WO2017023380A1 - Matériaux bi-dimensionnels et leurs utilisations - Google Patents

Matériaux bi-dimensionnels et leurs utilisations Download PDF

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Publication number
WO2017023380A1
WO2017023380A1 PCT/US2016/027637 US2016027637W WO2017023380A1 WO 2017023380 A1 WO2017023380 A1 WO 2017023380A1 US 2016027637 W US2016027637 W US 2016027637W WO 2017023380 A1 WO2017023380 A1 WO 2017023380A1
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WIPO (PCT)
Prior art keywords
graphene
dimensional
pores
pore
enclosure
Prior art date
Application number
PCT/US2016/027637
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English (en)
Inventor
Peter V. Bedworth
Steven E. Bullock
Scott E. Heise
Han Liu
Sarah M. Simon
Steven L SINSABAUGH
Steven W. Sinton
Jacob L. SWETT
Original Assignee
Lockheed Martin Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US15/099,193 external-priority patent/US20170035943A1/en
Priority claimed from US15/099,289 external-priority patent/US10376845B2/en
Application filed by Lockheed Martin Corporation filed Critical Lockheed Martin Corporation
Priority claimed from US15/099,276 external-priority patent/US20170037356A1/en
Priority claimed from US15/099,099 external-priority patent/US10696554B2/en
Priority claimed from US15/099,420 external-priority patent/US10118130B2/en
Priority claimed from US15/099,295 external-priority patent/US20170298191A1/en
Priority claimed from US15/099,304 external-priority patent/US10980919B2/en
Priority claimed from US15/099,269 external-priority patent/US10418143B2/en
Priority to EP16833433.2A priority Critical patent/EP3331588A4/fr
Priority claimed from US15/099,464 external-priority patent/US10017852B2/en
Priority claimed from US15/099,056 external-priority patent/US10203295B2/en
Priority claimed from US15/099,410 external-priority patent/US10213746B2/en
Priority claimed from US15/099,447 external-priority patent/US20170296982A1/en
Priority claimed from US15/099,482 external-priority patent/US20170296972A1/en
Priority claimed from US15/099,239 external-priority patent/US20170036911A1/en
Publication of WO2017023380A1 publication Critical patent/WO2017023380A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/10—Supported membranes; Membrane supports
    • B01D69/107—Organic support material
    • B01D69/1071—Woven, non-woven or net mesh
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M1/00—Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
    • A61M1/14—Dialysis systems; Artificial kidneys; Blood oxygenators ; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis
    • A61M1/16—Dialysis systems; Artificial kidneys; Blood oxygenators ; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis with membranes
    • A61M1/1621—Constructional aspects thereof
    • A61M1/1623—Disposition or location of membranes relative to fluids
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/06—Flat membranes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/10—Supported membranes; Membrane supports
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/10—Supported membranes; Membrane supports
    • B01D69/106—Membranes in the pores of a support, e.g. polymerized in the pores or voids
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/10—Supported membranes; Membrane supports
    • B01D69/108—Inorganic support material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/02—Inorganic material
    • B01D71/021—Carbon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/02—Inorganic material
    • B01D71/021—Carbon
    • B01D71/0211—Graphene or derivates thereof
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M1/00—Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
    • A61M1/14—Dialysis systems; Artificial kidneys; Blood oxygenators ; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis
    • A61M1/16—Dialysis systems; Artificial kidneys; Blood oxygenators ; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis with membranes
    • A61M1/1621—Constructional aspects thereof
    • A61M1/1631—Constructional aspects thereof having non-tubular membranes, e.g. sheets
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M2207/00—Methods of manufacture, assembly or production
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2325/00—Details relating to properties of membranes
    • B01D2325/02—Details relating to pores or porosity of the membranes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2325/00—Details relating to properties of membranes
    • B01D2325/02—Details relating to pores or porosity of the membranes
    • B01D2325/0283—Pore size
    • B01D2325/02832—1-10 nm
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2325/00—Details relating to properties of membranes
    • B01D2325/02—Details relating to pores or porosity of the membranes
    • B01D2325/0283—Pore size
    • B01D2325/02833—Pore size more than 10 and up to 100 nm
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2325/00—Details relating to properties of membranes
    • B01D2325/02—Details relating to pores or porosity of the membranes
    • B01D2325/0283—Pore size
    • B01D2325/02834—Pore size more than 0.1 and up to 1 µm
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/02—Inorganic material
    • B01D71/021—Carbon
    • B01D71/0212—Carbon nanotubes

Definitions

  • the present embodiments generally relate to two-dimensional materials, such as graphene as well as graphene platelet-based polymers, and methods of use and production thereof.
  • Graphene represents a form of carbon in which the carbon atoms reside within a single atomically thin sheet or a few layered sheets (e.g., about 20 or less) of fused six- membered rings forming an extended planar lattice. In its various forms, graphene has garnered widespread interest for use in a number of applications, primarily due to its favorable
  • a two dimensional material has a thickness of 0.3 to 1.2 nm. In other embodiment, a two dimensional material has a thickness of 0.3 to 3 nm.
  • pristine graphene typically displays the highest electrical conductivity values, it can sometimes be desirable to tune the electrical conductivity and modify the band structure. Tailoring of the band structure can be accomplished, for example, by introducing a plurality of defects (i.e., holes or perforations) within the graphene basal plane or increasing the number of such defects.
  • the band structure can be influenced by both the size, type, and number of holes present.
  • Applications that have been proposed for graphene include optical devices, mechanical structures, and electronic devices.
  • perforated graphene for filtration applications, particularly single-layer perforated graphene.
  • Current techniques used to perforate CVD graphene include oxidation processes (e.g., UV ozone, plasma oxidation, and high temperatures), ion beams, template cutting, and direct synthesis using specialized growth substrates.
  • Some embodiments include a process comprising: exposing a multilayered material to ions provided by an ion source, the multilayered material comprising a first layer comprising a two-dimensional first material and a second layer of a second material in contact with the first layer, the ions being provided with an ion energy ranging from 1.0 keV to 10 keV, and a flux from 0.1 nA/mm 2 to 100 nA/mm 2 ; and producing a perforated two-dimensional material by producing a plurality of holes in the two- dimensional first material by interacting a plurality of ions provided by the ion source, neutralized ions or a combination thereof with the two-dimensional first material and with the second material.
  • the cross-linked graphene platelet polymer comprising a plurality of cross-linked graphene platelets comprising a graphene portion and a cross-linking portion, the cross-linking portion contains a 4 to 10 atom link, and the cross-linked graphene platelet polymer being produced by reaction of an epoxide functionalized graphene platelet and a (meth)acrylate or (meth)acryl amide functionalized cross-linker; exposing blood from a patient to the blood filtration device having a hemodialysis membrane comprising the perforated two-dimensional material, the two-dimensional first material being disposed upon a porous support structure; removing a contaminant from the blood with the hemodialysis membrane; and recirculating purified blood to the patient.
  • the perforated two-dimensional material is graphene-based material.
  • graphene-based material is single-layer graphene.
  • the perforated two-dimensional material is graphene oxide.
  • the one or more occluding moieties are particles sized for at least partial introduction into an uncovered pore, but which cannot exit the uncovered pore.
  • the particles are deformable or swellable.
  • the particles are deformable and pressure or energy is applied to the particles after they are introduced into the at least one uncovered pore.
  • heat or light of a selected wavelength is applied to the particles after they are introduced into the at least one uncovered pore.
  • an electron or ion beam is applied to the particles after they are introduced into the at least one uncovered pore.
  • FIG. 1 shows an illustrative scanning electron microscope (SEM) image of defects and apertures that can be present in a graphene sheet on a porous substrate.
  • the illustrated graphene sheet has been transferred to an etched silicon nitride film in a rigid silicon support to create a composite membrane.
  • the diameter of arrayed substrate pores is 600nm.
  • Visible apertures in the graphene film appear black and range in size from approximately 10nm (limit of SEM resolution) to 600nm (fully uncovered substrate pore).
  • FIG. 2 shows an illustrative schematic demonstrating how a perforated graphene sheet or sheet of another two-dimensional material can undergo backside functionalization according to concepts described herein.
  • FIG. 3 shows an illustrative schematic demonstrating how a perforated graphene sheet or sheet of another two-dimensional material can undergo occlusion by flowing a catalyst there through according to concepts described herein.
  • FIG. 4 shows an illustrative schematic demonstrating how a perforated graphene sheet or sheet of another two-dimensional material can undergo occlusion with a carbonaceous material or a non-carbonaceous material in the presence of a light ion beam, or a high temperature annealing step according to concepts described herein.
  • FIG. 5 shows an illustrative schematic demonstrating how apertures in multiple layered graphene sheets or sheets of other two-dimensional materials can become differentially occluded according to concepts described herein.
  • FIG. 6 shows an illustrative schematic demonstrating occlusion of uncovered substrate pores in a composite membrane having a graphene-based material sheet disposed upon a porous substrate according to concepts described herein.
  • FIG. 7 shows an illustrative schematic demonstrating occlusion of uncovered substrate pores in a composite membrane having a graphene-based material sheet disposed upon a porous substrate according to concepts described herein.
  • the substrate pores are tapered to facilitate occlusion and anchoring of the particle in the uncovered pore.
  • FIG. 8 shows an illustrative schematic demonstrating occlusion of uncovered substrate pores in a composite membrane having a graphene-based material sheet disposed upon a porous substrate according to concepts described herein.
  • the substrate pores are exemplified as tapered.
  • an initial particle occludes the pore and secondary particles of size smaller than the initial particle are introduced into the uncovered occluded pores to facilitate anchoring and ensure complete occlusion.
  • FIG. 9 shows an illustrative schematic demonstrating occlusion of uncovered pores in a composite membrane having a graphene-based material sheet disposed upon a porous substrate according to concepts described herein.
  • the substrate pores are exemplified as having a ledge or other form of narrowing at the pore exit to facilitate retention and anchoring of the particle in the uncovered pore.
  • Such a ledge or other narrowing can for example be formed by deposition of a selected material to the backside of the substrate.
  • FIG. 10 shows an illustrative schematic demonstrating occlusion of uncovered substrate pores in a composite membrane having a graphene-based material sheet disposed upon a porous substrate according to concepts described herein. Pores in the substrate are illustrated as being interconnecting and non-uniform in diameter. Pores are shown as occluded by introduction of a plurality of particles.
  • FIG. 11 shows an illustrative schematic demonstrating occlusion of uncovered substrate pores in a composite membrane having a graphene-based material sheet disposed upon a porous substrate including swellable particles according to concepts described herein.
  • FIG. 12 shows an illustrative schematic demonstrating occlusion of uncovered substrate pores in a composite membrane having a graphene-based material sheet disposed upon a porous substrate according to concepts described herein.
  • no occluding moiety needs to be introduced into the uncovered pore.
  • the substrate material itself is swellable, on contact for example with an absorbable fluid. Swelling of the substrate material surrounding the uncovered pore results in occlusion of the pore.
  • FIG. 13 shows an illustrative schematic demonstrating occlusion of uncovered substrate pores in a composite membrane having a graphene-based material sheet disposed upon a porous substrate including an appropriate chemical reagent applied to initiate reaction between reactive groups on a particle and at a pore exit according to concepts described herein.
  • FIGs. 14A and 14B show an illustrative schematic demonstrating occlusion of uncovered pores in a composite membrane having a graphene-based material sheet disposed upon a porous substrate wherein energy, such as light of selected wavelengths is applied to the back side of the composite membrane to facilitate anchoring of the particle in the uncovered pore according to concepts described herein.
  • FIG. 14B illustrates resultant anchoring of the particle in the substrate pore.
  • FIGs. 15A and 15B show an illustrative schematic demonstrating occlusion of uncovered pores in a composite membrane having a graphene-based material sheet disposed upon a porous substrate wherein energy is applied to the back side of the composite membrane to deform and conglomerate or active chemical reactions between particles and/or between particles and the pores surfaces or edges to facilitate anchoring of particle in the uncovered pore according to concepts described herein.
  • FIG. 15B illustrates resultant anchoring of the particle in the substrate pore
  • FIG. 16 shows an illustrative schematic showing steps in an exemplary uncovered pore occlusion process according to concepts described herein.
  • FIG. 17 shows an illustrative schematic showing steps in another exemplary uncovered pore occlusion process according to concepts described herein.
  • FIG. 18 shows an illustrative schematic showing steps in another exemplary uncovered pore occlusion process according to concepts described herein.
  • FIG. 19 is an illustrative schematic demonstrating occlusion of uncovered pores by the process of Figure 18 according to concepts described herein.
  • the substrate pore is illustrated as having uniform diameter along its length. Shaped pores can also be employed.
  • the illustrated embodiment shows the formation of a cured material or polymer within the uncovered pore to occlude the pore.
  • FIGs. 20A and 20B are SEM images illustrating latex bead healing (occlusion) of uncovered pores in a composite membrane according to concepts described herein.
  • FIGs. 21A and 21B are SEM images illustrating the progress of latex bead healing (occlusion) of uncovered pores in a composite membrane according to concepts described herein.
  • FIG. 22A is a graph of flow rate ( ⁇ ) (left axis, diamonds) and cumulative permeate (right axis, squares) as a function of time through a composite membrane that is being subjected to uncovered substrate pore occlusion according to concepts described herein.
  • FIG. 22B is a SEM image showing occlusion of 1250nm diameter pores in a silicon nitride substrate by a single graphene sheet
  • FIG. 22C is a SEM image of occlusion of 1250nm diameter pores in a silicon nitride substrate after subsequent application of a second sheet of graphene.
  • FIG. 23 is an example reaction scheme of some embodiments.
  • FIG. 24 is an example configuration of a filter module of some embodiments.
  • FIGURE 25 shows an illustrative schematic of some embodiments of a composite structure comprising a two-dimensional material and a two fibrous layers. The fibrous layers allow for capillary ingrowth that brings the blood supply close to the two-dimensional material to facilitate exchange of molecules with the cells, proteins, tissue or the like on the opposite side of the two-dimensional material. SEM micrographs show embodiments with fibrous layers that have different pore sizes.
  • FIGURES 26A-F illustrate some embodiments with various configurations of enclosure configurations.
  • FIGURES 27A and 3B are schematic illustrations of some embodiments of an enclosure implemented for immunoisolation of living cells.
  • FIGURES 28A-C illustrate some embodiments for preparing an enclosure.
  • FIG. 29 is a top down representation of a graphene material including repaired defects.
  • FIG. 30 is a cross-section of the graphene material of FIG. 29 along line A-A' .
  • FIG. 31 is a representation of a graphene material including defects and pores when exposed to a first reactant and a second reactant to repair the defects through interfacial polymerization.
  • FIG. 32 is a representation of the graphene material of FIG. 31 after the reactants have contacted each other through the defect.
  • FIG. 33 is the graphene material of FIG. 32 after the polymerization of the reactants forming a polymer region filling the defect.
  • FIG. 34 is a representation of a repaired graphene material, according to one embodiment.
  • FIG. 35 is a representation of a repaired graphene material, according to one embodiment.
  • FIG. 36 is a representation of a repaired graphene material, according to one embodiment.
  • FIG. 37 is a representation of a graphene material including a defect when exposed to a first reactant and a second reactant to repair the defect through interfacial polymerization.
  • FIG. 38 is a representation of the graphene material of FIG. 37 after the reactants have contacted each other through the defect.
  • FIG. 39 is a top down representation of a graphene material including pores, holes, and defects.
  • FIG. 40 is the graphene material of FIG. 39 after the holes and defects have been filled by interfacial polymerization.
  • FIG. 41 is a top down representation of a graphene material that has undergone interfacial polymerization to repair defects and form a polymer handling region.
  • FIG. 42 is a representation of a cross-section of a graphene material that has undergone interfacial polymerization to repair defects and form a polymer handling region, where the graphene material is adhered to a support.
  • FIG. 43 is a top down representation of an enclosure including a graphene material and a polymer handling region.
  • FIG. 44 is a cross-section of the enclosure of FIG. 43 along line B-B' .
  • FIG. 45 is a top down representation of a graphene material that includes holes formed therein arranged such that an in-situ grown support structure may be produced.
  • FIG. 46 is a top down representation of the graphene material of FIG. 45 after undergoing interfacial polymerization.
  • FIG. 47 is a representation of a cross-section of FIG. 46 along line C-C .
  • FIG. 48 is a representation of a cross-section of a graphene material that has undergone interfacial polymerization to repair defects and form a polymer handling region, where the graphene material is adhered to a support such that the distance between the polymer regions on the support is less than the length of the graphene between the polymer regions.
  • FIG. 49 is a perspective view of a two-dimensional membrane layered structure according to one embodiment.
  • FIG. 50 is a perspective of the two-dimensional membrane layered structure of FIG. 49 having fluid flow passages.
  • FIG. 51 is a cross-sectional view of the two-dimensional membrane layered structure having the flow passages of FIG. 50 according to a first embodiment.
  • FIG. 52 is a cross-sectional view of the two-dimensional membrane layered structure having the flow passages of FIG. 50 according to a second embodiment.
  • FIG. 53 is a scanning electron microscope (SEM) micrograph of a support substrate layer having interlayer supports to form fluid flow passages.
  • FIG. 54 is a detailed SEM micrograph of the support substrate layer of FIG. 53.
  • FIG. 55 illustrates some embodiments having a membrane with two porous graphene- based material layers, where the membrane allows passage of both water and salt ions.
  • FIG. 56 illustrates some embodiments having a membrane with two porous graphene- based material layers, where applied pressure on the membrane excludes passage of salt ions.
  • FIG. 57 illustrates some embodiments having a membrane with three porous graphene-based material layers, where applied pressure on the membrane excludes passage of salt ions.
  • FIG. 58 illustrates some embodiments having a membrane with two porous graphene- based material layers, where applied voltage across the membrane excludes passage of salt ions.
  • FIG. 59 shows photographs of some embodiments of contamination-based spacer substances formed into various shapes or patterns.
  • Figure 59A shows contamination-based substances formed into a single line.
  • Figure 59B shows contamination-based substances patterned into a star.
  • Figures 59C and 59D show contamination-based spacer substances formed into a dot array ( Figure 59D provides a photograph with increased magnification as compared to Figure 59C).
  • FIGURE 60 is a schematic of some embodiments of graphene.
  • FIGURES 61 A-E show illustrative schematics of some embodiments with various configurations of enclosure configurations comprising a two-dimensional material.
  • FIGURES 62A and 62B are schematic illustrations of some embodiments of an enclosure implemented for immunoisolation of living cells.
  • FIGURES 63A-63C illustrate some embodiments for preparing an enclosure.
  • FIGURE 64 shows an illustrative SEM micrograph of some embodiments with a plurality of electrospun PVDF fibers deposited on graphene.
  • FIGURE 65 shows an illustrative schematic of some embodiments of a composite structure comprising a two-dimensional material and a two fibrous layers. The fibrous layers allow for capillary ingrowth that brings the blood supply close to the two-dimensional material to facilitate exchange of molecules with the cells, proteins, tissue or the like on the opposite side of the two-dimensional material. SEM micrographs show embodiments with fibrous layers that have different pore sizes.
  • FIGURE 66 shows schematic illustrations of some embodiments of composite structures comprising two-dimensional materials (e.g., graphene), an optional intermediate layer (e.g., track etched polymer membrane), and a fibrous layer having a tighter fiber spacing nearer the two-dimensional material and an increasing effective pore size further from the two- dimensional material.
  • Figure 66A also shows SEM micrographs from various locations in the composite structure. Also included are variants with direct substrate deposition (66B), hybrid thin membrane + deposition (66C), hybrid substrate deposition + thin film polymer sandwiching a graphene layer (66D) and hybrid substrate position + thin polymer film on the same side of a graphene layer.
  • FIGURE 67 shows an illustrative schematic of some embodiments of corrugation of graphene or graphene-based material after chemical vapor deposition on a planar growth substrate (1) by: pressing the graphene or graphene-based material and growth substrate onto a corrugated template (2); followed by application of an electrospun fibrous layer (3); removal of the graphene or graphene-based material, growth substrate and fibrous layer from the template (4); and etching of the growth substrate (5), to produce graphene or graphene-based material on electrospun material with a high surface area (6).
  • FIGURE 68 shows an illustrative schematic of some embodiments of a corrugated cylindrical workpiece for receiving graphene or graphene-based material on a growth substrate, as shown in Figure 65. Electrospray deposition of a fibrous layer on a non-rotated or planar surface produces a randomly distributed fibrous layer (A), whereas rotation of a cylindrical workpiece during the electrospray process produces an aligned fibrous layer (B). In the figure, entire outside of the cylinder is corrugated. [0078] FIGURE 69 shows an illustrative schematic of some embodiments of a process for manufacturing a two-dimensional material on a fibrous layer with mesh reinforcement.
  • FIGURE 70 shows a SEM micrograph of some embodiments of two layers of graphene or graphene-based material on a fibrous layer.
  • FIGURE 71 shows SEM micrographs of some embodiments of single-layer or two- layer graphene on a substrate at various magnifications and using two different electrospinning recipes, as set forth in the figure. In both recipes, 7% nylon 6,6 was electrospun and graphene was transferred to the electrospun layer. Arrows in the figure demonstrate defects and/or areas where the graphene drapes.
  • FIGURE 72 shows a high-magnification SEM micrograph of some embodiments of single-layer graphene on a substrate prepared according to recipe 1 in Figure 71.
  • FIGURE 73A shows micrographs of some embodiments of substrate layers (e.g., termed “tortuous path membrane” and “track etched membrane” in the figure); a two- dimensional membrane; and a composite structure with both a substrate layer and a two- dimensional membrane layer.
  • FIGURE 73B illustrates exemplary embodiments of materials subjected to cytotoxicity testing and implantation testing.
  • Figure 73 C shows photographs of some embodiments of exemplary test materials used in cytotoxicity studies.
  • FIGURE 74 illustrates some embodiments for using graphene in methods of immunoi sol ati on .
  • FIGURE 75 illustrates some embodiments for preparing and using graphene in methods of immunoisolation.
  • FIGURE 76 illustrates some embodiments of devices prepared with a composite structure (e.g., a substrate layer + a perforated graphene layer).
  • a composite structure e.g., a substrate layer + a perforated graphene layer.
  • FIGURE 77 illustrates examples of substances that can be selectively excluded by two-dimensional graphene in some embodiments, based on the size of the pores in the two- dimensional graphene (graphics not to scale).
  • FIGURE 78 shows some embodiments of graphene disposed on various substrates, including: track-etched polyimide, track-etched polycarbonate, microporous SiN, electrospun membrane, PVDF microfiltration membrane, nanoporous SiN, carbon nanomaterial membrane, and SiN microseive.
  • the right-most sub-figures show increased magnification views of graphene on an SiN microporous substrate.
  • FIGURE 79 shows micrographs of some embodiments of custom track-etched polyimide (TEPI).
  • FIGURE 80 shows a micrograph of some embodiments of graphene disposed on track-etched polyimide that has been nanoparticle perforated.
  • FIGURE 81 shows a magnified view of the micrograph shown in Figure 80.
  • the right side of the figure is an increased magnification view that corresponds with the white box on the left side of the figure.
  • FIGURE 82 shows a micrograph of some embodiments of graphene disposed on electrospun nylon 6,6.
  • FIGURE 83 shows a magnified view of the micrograph shown in Figure 82.
  • FIGURE 84 shows diffusive transport of small (Allura Red AC) and large (silver nanoparticles) analytes across a substrate layer and a perforated graphene layer of some embodiments as compared to a control.
  • the lighter-shaded bars correspond to permeability of Allura Red AC
  • the darked-shaded bars correspond to the ration of Allura Red AC permeability: silver nanoparticle permeability.
  • the figure also includes a picture of a device that can be used to test diffusive transport.
  • FIGURE 85 shows data related to normalized diffusive transport of fluorescein conjugated to immunoglobulin-G (IgG) across a SiN substrate layer, a control membrane (Biopore), a perforated graphene layer, and an unperforated graphene layer.
  • IgG immunoglobulin-G
  • the order of bars from left to right correspond with: (i) Bare Chip (left-most bar), (ii) perforated graphene, (iii) unperforated graphene (bar with lowest flux), and (iv) Biopore (right-most bar).
  • the lines correspond, from highest IgG concentration to lower IgG
  • FIGURE 86 shows data related to permeability of fluorescein across perforated graphene (line with highest analyte concentration in the graph) and a control membrane
  • FIGURE 87 shows photographs of some embodiments where 100 nm diameter Red (580/605) FluoSpheres are restricted from traversing perforated graphene, but fluorescein is able to traverse the perforated graphene.
  • FIGURE 88 shows data related to permeability of fluorescein across various substrate layers, substrate layers coated with perforated graphene, and unperforated graphene.
  • the left-most section relates to permeability experiments conducted on a control membrane (Biopore);
  • the middle section relates to permeability experiments conducted with uncoated substrate TEPI-400/7 (the left two bars in the middle section) and TEPI-400/7 coated with 2 layers of unperforated graphene (the right-most bar in the middle section);
  • the right-most section relates to permeability experiments conducted with uncoated substrate TEPI-460/25 (the left five bars), TEPI-460/25 coated with 2 layers of perforated graphene (the two bars with the lowest permeability), and TEPI-460/25 coated with perforated graphene (the right six bars).
  • Figure 89A shows data related to permeability of fluorescein across an uncoated substrate, across a perforated graphene-coated substrate, and across an unperforated graphene- coated substrate.
  • Figure 89B shows data related to permeability of FluoroShere across an uncoated substrate and a graphene-coated substrate.
  • FIGURE 90 shows TEM images of some embodiments of perforated graphene with various pore sizes.
  • the two left-most images show perforated graphene with relatively small pores; the two right-most images show perforated graphene with relatively large pores.
  • FIGURE 91 shows SEM images of some embodiments showing consistent perforation of graphene over relatively large areas.
  • FIGURE 92 shows SEM images of some embodiments showing the ability to tune pore sizes in perforated graphene via dilation.
  • FIG. 93 is a flow chart illustrating a method of forming a graphenic-based membrane according to concepts disclosed herein.
  • FIG. 94 is a scanning transmission electron microscopy (STEM) micrograph of a graphene-based material before charged particle irradiation at a level for healing according to concepts disclosed herein.
  • FIG. 95 is a magnified image of the STEM micrograph of FIG. 94 with arrows pointing to some identified defects.
  • FIG. 96 is a STEM micrograph of the region shown in FIG. 95 after charged particle irradiation for healing.
  • FIG. 97 is a STEM micrograph of another region of the graphene-based material shown in FIG. 94 before charged particle irradiation at a level for healing.
  • FIG. 98 is a STEM micrograph of the region shown in FIG. 97 after charged particle irradiation for healing.
  • FIG. 99 is a transmission electron microscope (TEM) image illustrating a graphene based material after conditioning treatment.
  • FIG. 100 is another TEM image illustrating a graphene based material after conditioning treatment.
  • FIGS. 101A and 101B are transmission electron microscope (TEM) images illustrating a portion of a sheet of graphene based material after perforation using UV-oxygen treatment.
  • TEM transmission electron microscope
  • FIGS. 102A and 102B are TEM images illustrating a portion of a sheet of graphene based material after perforation using Xe+ ions.
  • FIG. 103 and FIG. 104 are TEM images illustrating graphene based material after perforation using Ne+ ions.
  • FIG. 105 and FIG. 106 are TEM images illustrating graphene based material after perforation using He+ ions.
  • FIG. 107 is a transmission electron microscopy image demonstrating perforation through two independently stacked layers of graphene by nanoparticles.
  • FIG. 108 is a transmission electron microscopy image demonstrating perforation through bilayer graphene by nanoparticles.
  • FIG. 109 is a transmission electron microscopy image demonstrating perforation by a collimated nanoparticle beam at a non-zero angle with respect to the normal of the graphene- containing sheet.
  • FIGS 110A and H0B show the porosity present in a graphene-containing sheet after nanoparticle perforation (FIG. 110A) and after nanoparticle perforation followed by ion beam irradiation (FIG. H0B).
  • FIG. 111 is a scanning electron microscopy image of two independently stacked layers of single layer graphene on a TEPI (460/25) substrate perforated by Ag P particles.
  • FIG. 112 shows a flowchart for a method for monitoring defect formation or healing via detection of scattered, emitted or transmitted radiation or particles, according to some embodiments.
  • FIG. 113 shows a flowchart for a method for monitoring defect formation or healing via detection of movement of an analyte, according to some embodiments.
  • FIG. 114 shows a flowchart for a method for monitoring defect formation or healing via measurement of electrical conductivity, according to some embodiments.
  • FIG. 115 shows a flowchart for a method for monitoring defect formation or healing via Joule heating and temperature measurement, according to some embodiments.
  • FIGs. 116A and 116B show schematics of exemplary systems for monitoring defect formation or healing, according to the embodiments of the present invention.
  • FIG. 117A is a schematic, perspective view of a growth substrate used in the formation of a graphene sheet according to some embodiments.
  • FIG. 117B is a schematic, perspective view of the graphene sheet formed on the growth substrate of FIG. 117 A.
  • FIG. 118 is a schematic view of a transfer preparation apparatus to prepare the graphene sheet of FIG. 117B for free-float transfer.
  • FIG. 119A is a schematic, perspective view of an etching step of the growth substrate from the prepared graphene sheet of FIG. 118 using a free-float transfer method.
  • FIG. 119B is a schematic, perspective view of a transfer step of the prepared graphene sheet of FIG. 118 to a functional substrate using the free-float transfer method.
  • FIG. 120 shows a large-scale graphene sheet prepared using the transfer preparation apparatus of FIG. 118 after removal of the growth substrate.
  • FIG. 121 shows the large-scale graphene sheet of FIG. 120 after transfer to a functional substrate using the free-float transfer method.
  • FIG. 122 is a scanning electron microscope (SEM) micrograph of a graphene sheet transferred to a functional substrate using the free-float transfer method.
  • FIG. 123 is a detailed view of the SEM micrograph of FIG. 122.
  • the two-dimensional material comprises graphene, carbon nanomembranes (CNM), molybdenum disulfide, or boron nitride (specifically the hexagonal crystalline form of boron nitride).
  • the two-dimensional material is a graphene-based material.
  • the two-dimensional material is graphene.
  • Graphene according to embodiments can include single-layer graphene, multi -layer graphene, or any combination thereof.
  • Other nanomaterials having an extended two- dimensional molecular structure can also constitute the two-dimensional material in the various embodiments.
  • molybdenum sulfide is a representative chalcogenide having a two- dimensional molecular structure
  • other various chalcogenides can constitute the two- dimensional material in the embodiments.
  • Choice of a suitable two-dimensional material for a particular application can be determined by a number of factors, including the chemical and physical environment into which the graphene or other two-dimensional material is to be terminally deployed.
  • the two dimensional material useful in membranes herein is a sheet of graphene-based material.
  • Graphene-based materials include, but are not limited to, single layer graphene, multilayer graphene or interconnected single or multilayer graphene domains and combinations thereof.
  • graphene-based materials also include materials which have been formed by stacking independent single sheet or multilayer graphene sheets.
  • multilayer graphene includes 2 to 20 layers, 2 to 10 layers or 2 to 5 layers.
  • graphene is the dominant material in a graphene-based material.
  • a graphene-based material comprises at least 30% graphene by weight, or at least 40% graphene, or at least 50% graphene, or at least 60% graphene, or at least 70% graphene, or at least 80%) graphene, or at least 90% graphene, or at least 95% graphene.
  • a graphene-based material comprises a range of graphene content selected from 30% to 95%, or from 40% to 80% from 50% to 70%, from 60% to 95% or from 75% to 100%.
  • a graphene-based material comprises a range of up to 35% oxygen by atomic ratio.
  • a "domain” refers to a region of a material where atoms are uniformly ordered into a crystal lattice.
  • a domain is uniform within its boundaries, but different from a neighboring region.
  • a single crystalline material has a single domain of ordered atoms.
  • at least some of the graphene domains are nanocrystals, having a domain size from 1 to 100 nm or 10-100 nm and optionally up to about 1 cm.
  • at least some of the graphene domains have a domain size greater than 100 nm to 1 micron, or from 200 nm to 800 nm, or from 300 nm to 500 nm and optionally up to about 1 cm.
  • a first crystal lattice may be rotated relative to a second crystal lattice, by rotation about an axis perpendicular to the plane of a sheet, such that the two lattices differ in "crystal lattice orientation".
  • the sheet of graphene-based material comprises a sheet of single or multilayer graphene or a combination thereof. In an embodiment, the sheet of graphene-based material is a sheet of single or multilayer graphene or a combination thereof. In another embodiment, the sheet of graphene-based material is a sheet comprising a plurality of
  • interconnected single or multilayer graphene domains are covalently bonded together to form the sheet.
  • the sheet is polycrystalline.
  • the thickness of the sheet of graphene-based material is from 0.34 to 10 nm, from 0.34 to 5 nm, or from 0.34 to 3 nm.
  • a sheet of graphene-based material comprises intrinsic or native defects. Intrinsic or native defects are those resulting from preparation of the graphene-based material in contrast to perforations which are selectively introduced into a sheet of graphene-based material or a sheet of graphene. Such intrinsic or native defects include, but are not limited to, lattice anomalies, pores, tears, cracks or wrinkles. Lattice anomalies can include, but are not limited to, carbon rings with other than 6 members (e.g. 5, 7 or 9 membered rings), vacancies, interstitial defects (including incorporation of non- carbon atoms in the lattice), and grain boundaries.
  • a sheet of graphene-based material optionally further comprises non-graphenic carbon-based material located on the surface of the sheet of graphene-based material.
  • the non-graphenic carbon-based material does not possess long range order and may be classified as amorphous.
  • the non-graphenic carbon-based material further comprises elements other than carbon and/or hydrocarbons.
  • Non-carbon elements which may be incorporated in the non-graphenic carbon include, but are not limited to, hydrogen, oxygen, silicon, nitrogen, copper and iron.
  • the non-graphenic carbon-based material comprises hydrocarbons.
  • carbon is the dominant material in non-graphenic carbon-based material.
  • a non-graphenic carbon-based material comprises at least 30% carbon by weight, or at least 40% carbon, or at least 50% carbon, or at least 60% carbon, or at least 70% carbon, or at least 80% carbon, or at least 90% carbon, or at least 95% carbon.
  • a non-graphenic carbon-based material comprises a range of carbon selected from 30% to 95%, or from 40% to 80%, or from 50% to 70%.
  • Two-dimensional materials in which pores are intentionally created are referred to herein as “perforated,” such as “perforated graphene-based materials,” “perforated two- dimensional materials,” or “perforated graphene.”
  • Two-dimensional materials are, most generally, those which have atomically thin thickness from single-layer sub-nanometer thickness to a few nanometers and which generally have a high surface area.
  • Two-dimensional materials include metal chalogenides (e.g., transition metal dichalogenides), transition metal oxides, hexagonal boron nitride, graphene, silicene and germanene (see: Xu et al. (2013) "Graphene-like Two-Dimensional Materials) Chemical Reviews 113 :3766-3798).
  • Two-dimensional materials include graphene, a graphene-based material, a transition metal dichalcogenide, molybdenum disulfide, a-boron nitride, silicene, germanene, or a combination thereof.
  • Other nanomaterials having an extended two-dimensional, planar molecular structure can also constitute the two-dimensional material in the various embodiments.
  • molybdenum disulfide is a representative chalcogenide having a two-dimensional molecular structure, and other various chalcogenides can constitute the two-dimensional material in embodiments.
  • two-dimensional boron nitride can constitute the two- dimensional material in an embodiment of the concepts disclosed herein.
  • Choice of a suitable two-dimensional material for a particular application can be determined by a number of factors, including the chemical and physical environment into which the graphene, graphene-based or other two-dimensional material is to be deployed.
  • the present disclosure is directed, in part, to sheets of graphene-based material or other two-dimensional materials containing a plurality of perforations therein, where the perforations have a selected size and chemistry, as well as pore geometry.
  • the perforated graphene, perforated graphene-based materials and other perforated two-dimensional materials contain a plurality of size-selected perforations ranging from about 3 to 15 angstroms in size.
  • the perforation size ranges from 3 to 10 angstroms or from 3 to 6 angstroms in size.
  • the present disclosure is further directed, in part, to perforated graphene, perforated graphene-based materials and other perforated two-dimensional materials containing a plurality of size-selected perforations ranging from about 3 to 15 angstroms in size and having a narrow size distribution, including but not limited to a 1-10% deviation in size or a 1-20% deviation in size.
  • the characteristic dimension of the perforations is from about 3 to 15 angstroms in size.
  • the present disclosure is also directed, in part, to perforated graphene, perforated graphene-based materials and other perforated two-dimensional materials containing a plurality of perforations ranging from about 5 to about 1000 angstroms in size.
  • the perforations range from 10 to 100 angstroms, 10 to 50 angstroms, 10 to 20 angstroms or 5 to 20 angstroms.
  • the perforation size ranges from 100 nm up to 1000 nm or from 100 nm to 500 nm.
  • the present disclosure is further directed, in part, to perforated graphene, perforated graphene-based materials and other perforated two-dimensional materials containing a plurality of perforations ranging from about 5 to 1000 angstrom in size and having a narrow size distribution, including but not limited to a 1-10% deviation in size or a 1-20% deviation in size.
  • the characteristic dimension of the perforations is from 5 to 1000 angstrom.
  • the characteristic dimension is the diameter of the perforation or aperture.
  • the characteristic dimension can be taken as the largest distance spanning the perforation or aperture, the smallest distance spanning the perforation or aperture, the average of the largest and smallest distance spanning the perforation or aperture, or an equivalent diameter based on the in-plane area of the perforation or aperture.
  • perforated graphene-based materials include materials in which non-carbon atoms have been incorporated at the edges of the pores.
  • the present disclosure particularly describes methods directed to occluding apertures in a sheet of a graphene-based material or other two-dimensional material that are larger than a given threshold size, thereby reducing the plurality of apertures to a desired size and optionally with a specific chemistry.
  • the reduced size of the aperture falls within the perforation and aperture size ranges given above.
  • the threshold size can be chosen at will to meet the needs of a particular application.
  • Perforations or apertures are sized as described herein to provide desired selective permeability of a species (atom, molecule, protein, virus, cell, etc.) for a given application.
  • Selective permeability relates to the propensity of a porous material or a perforated two-dimensional material to allow passage (or transport) of one or more species more readily or faster than other species. Selective permeability allows separation of species which exhibit different passage or transport rates through perforations or apertures. In two-dimensional materials selective permeability correlates at least in part to the dimension or size (e.g., diameter) of perforations or apertures and the relative effective size of the species. Selective permeability of the perforations or apertures in two-dimensional materials such as graphene-based materials can also depend on functionalization of the perforation or aperture (if any) and the specific species that are to be separated.
  • selective permeability can be affected by application of a voltage bias to the membrane.
  • Selective permeability of gases can also depend upon adsorption of a gas species on the filtration material, e.g., graphene. Adsorption at least in part can affect the local concentration of the gas species at the surface of the filtration material. Separation of two or more species in a mixture includes a change in the ratio(s) (weight or molar ratio) of the two or more species in the mixture after passage of the mixture through a perforated two-dimensional material.
  • the chemistry of the perforated apertures can be the same or different after being occluded according to the embodiments described herein.
  • occluding the apertures can involve occluding apertures within a particular size range such that no apertures remain within the size range, thereby conferred selectivity to the "healing" of the graphene-based material or other two-dimensional material.
  • the embodiments of the healing processes described herein are applicable to both "through-holes" (i.e., pores in a single two-dimensional sheet) and "intralayer flow” (i.e., passages existing between stacked layers of individual single layer two-dimensional sheets or multiple layer sheets of 2D material. Passages can include laterally offset pores within multiple two-dimensional sheets. Through-holes can also exist in multiple two-dimensional sheets when the pores are not substantially laterally offset from one another in the various layers
  • the embodiments described herein allow specific chemistries to be readily applied in a homogenous manner to graphene-based materials and other two-dimensional materials to allow for tunable activity across many applications. While the chemistries described herein can be applied homogenously to an entire surface of the sheet of graphene or other two-dimensional material, they generally provide specific activation of particular perforations or apertures of a given size using a carefully sized moiety that allows for aperture modification to take place.
  • the described techniques can be advantageous in allowing the homogenous application of chemistry to the graphene-based material or other two-dimensional material surface while only occluding perforations or apertures of a certain desired size.
  • the homogenous application of the various chemistries described herein can facilitate scalable production and manufacturing ease.
  • Perforation or aperture modification can confer a specific chemistry to the perforations or apertures (e.g., functional selectivity, hydrophobicity, and the like) and allow for at least partial occlusion of the perforations or apertures to take place in various embodiments.
  • Such selective modification of the apertures can allow selective separations to take place using the graphene- based material, including size-based separations.
  • perforations or apertures can be selectively modified by various known methods to contain hydrophobic moieties, hydrophilic moieties, ionic moieties, polar moieties, reactive chemical groups, for example, amine-reactive groups (chemical species that react with amines) carboxylate-reactive groups (chemical species that react with carboxylates), amines or carboxylates (among many others), polymers and various biological molecules, including for example, amino acids, peptide, polypeptides, enzymes or other proteins, carbohydrates and various nucleic acids.
  • the techniques described herein can be configured to at least partially occlude large apertures within the sheet of graphene-based material or other two-dimensional material in preference to smaller apertures, thereby allowing the smaller apertures to remain open and allow flow to be maintained therethrough.
  • This type of selective flow can allow molecular sieving to take place using the graphene-based material or other two-dimensional material, rather than the solution-diffusion model provided by current polymeric solutions.
  • apertures or defects are blocked to provide flow reduction or blockage within a range of 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, 95% or more.
  • all the apertures and/or defects in a graphene-based material or other two-dimensional material can be occluded in order to substantially block passage or flow, herein 99% or more through the two-dimensional material or block passage or flow through the two-dimensional material entirely.
  • a graphene-based material or other two-dimensional material that is occluded in order to substantially or entirely block passage or flow through the material can be used as a starting material for forming a size-selected perforated two- dimensional material. Size-selected perforations can be introduced into the substantially or entirely blocked two-dimensional material employing art known methods for generating perforations of a selected size and, if any, a selected functionalization.
  • the description herein is primarily directed to graphene-based materials, it is to be recognized that other two-dimensional materials or near two-dimensional materials can be treated in a like manner.
  • the at least partially occluded graphene-based materials prepared according to the techniques described herein can be used for occluding fluid flow, particularly liquid or gas flow for separations, including filtration membranes and filtration systems. In addition, they can be used in optical or electronic applications.
  • the graphene-based material can be transferred from its growth substrate to a porous substrate in the course of, before or after practicing the embodiments described herein.
  • a sheet of a graphene-based material or sheet of another two- dimensional material can have a plurality of perforations therein, and a direction of fluid flow therethrough can establish an "upstream" side (alternative the top surface) and a "downstream” side (alternatively the bottom surface) of the sheet.
  • the downstream side of the sheet of the graphene-based material or sheet of another two-dimensional material can be next to or in contact with a substrate, such as a porous substrate.
  • the substrate can provide support to the sheet of the graphene-based material while practicing the various techniques described herein.
  • the perforations in the sheet of a graphene-based material or sheet of another two-dimensional material can be intentionally placed therein, or they can occur natively during its synthesis.
  • the perforations can have a distribution of sizes, which can be known or unknown.
  • a fluid containing a sized moiety can be flowed through the sheet of graphene-based material or other two-dimensional material.
  • the sized moiety can lodge in some of the apertures in the sheet and induce occlusion of at least the portion of the apertures in the sheet in which the sized moiety lodges.
  • a sized moiety can occlude fluid flow on the sheet of graphene-based material or other two- dimensional material from the upstream side of the graphene.
  • Occluding at least a portion of the apertures in the foregoing manner can result in reducing the size and number of apertures, possibly modifying a flow path and making the graphene-based material or other two-dimensional material suitable for use in an intended application.
  • the graphene-based material or sheet of another two-dimensional material can be processed in the foregoing manner to produce a cutoff pore size in a molecular filter.
  • the moiety can be covalently or non-covalently attached to the graphene-based material, or mechanically connected to the graphene-based material.
  • the "downstream" side of the sheet of graphene-based material can be "primed” or functionalized with oxygen via plasma oxidation or the like, such that the graphene-based material can be reactive with a moiety passing through the apertures.
  • the moiety in the flow path can bind to functional groups introduced to the graphene-based material, such that the moiety binds to the graphene-based material and the apertures become at least partially occluded.
  • Suitable binding motifs can include, but are not limited to, addition chemistry, crosslinking, covalent bonding, condensation reactions, esterification, or polymerization.
  • the occluding moiety can be sized to reflect a particular cutoff regime, such that it only passes through apertures having a certain threshold size or shape.
  • the occluding moieties can be a substantially flat molecule or spherical in shape.
  • POSS® silicones polyhedral oligomeric silsesquioxanes
  • Other examples, of useful occluding moieties include fullerenes, dendrites, dextran, micelles or other lipid aggregates, and micro-gel particles. Some or all of these techniques may be applied to other two-dimensional materials as well.
  • the graphene-based material can be perforated and functionalized with oxygen, such as treating the graphene-based material with oxygen or a dilute oxygen plasma, thereby functionalizing the graphene-based material with oxygen moieties.
  • the graphene based material can be functionalized in this manner while on a copper substrate, or any other metallic/growth or polymeric substrate as would be known by those with ordinary skill in the art.
  • the oxygen functionalities can be reacted via a chemistry that converts the oxygenated functionalities into a leaving group (such as a halide group, particularly a fluoro group, or sulfonic acid analogs, such as tosylates, triflates, mesylates, and the like).
  • a leaving group such as a halide group, particularly a fluoro group, or sulfonic acid analogs, such as tosylates, triflates, mesylates, and the like.
  • This chemistry results in sites on the substrate that are vulnerable to nucleophilic attack and can be used for additional chemistry, as detailed above, or allowing the graphene based material to bind to the substrate.
  • the graphene-based material can functionalized with oxygen so as to provide graphene oxide platelet membranes.
  • FIG. 2 shows an illustrative schematic demonstrating how a graphene sheet or sheet of another two-dimensional material can undergo backside functionalization according to the embodiments described herein to occlude undesired apertures or defects in the sheet.
  • Side A refers to the side of the graphene or other two-dimensional material being exposed to the upstream flow
  • Side B refers to the backside of the graphene or other two- dimensional material.
  • the flow may be across the two dimensional material instead of merely through.
  • the backside of the sheet may be primed or activated to react with the occluding moieties.
  • the backside of the sheet is functionalized to bind or react with occluding moieties.
  • the occluding moieties do not pass through aperture or defects having a size too small for the occluding moieties to pass through, but the occluding moieties do pass through the larger undesirable apertures or defects.
  • the occluding moieties react and/or bind at the aperture or defect and occlude the aperture or defect.
  • the flow is sufficiently high that diffusion of occluding moieties on the backside of the sheet away from the aperture that the exit is minimized to avoid occlusion of the smaller apertures or defects.
  • a sheet of graphene or other two-dimensional material can also be functionalized or primed such that it can undergo front side attack, particularly in cases where transfer is less desirable during the processing of a product.
  • Front side attack can ensure retention of configuration. Front side attack can occur similarly to the methods depicted in FIG. 2, with the exception that bonding occurs on the upstream or Side A of the graphene sheet or sheet of other two-dimensional material and there may be less selectivity in bonding holes of a desired size over larger apertures.
  • methods to permit front side attack on the surface of a graphene-based material again begin with an oxygen functional group on the surface of the graphene-based material, which are treated with an agent such as pyridine, triflate, or analogs thereof to provide a good leaving group.
  • an agent such as pyridine, triflate, or analogs thereof to provide a good leaving group.
  • Subsequent chemistry can be conducted to remove the copper growth substrate and use additional chemistry to occlude holes or apertures below the diameter which the moiety may pass. Note that both front side and back side approaches allow for a
  • the downstream side of the graphene-based material or other two-dimensional material can be primed with an occluding substance and a moiety that catalyzes the reaction of the occluding substance with the graphene or other two-dimensional material can pass through the apertures.
  • the moiety does not become bonded to the graphene or other two-dimensional material itself.
  • Figure 3 shows an illustrative schematic demonstrating how a perforated graphene sheet or sheet of another two-dimensional material can undergo occlusion by flowing a catalyst therethrough.
  • the methods can include treating the graphene or graphene-based material with lithium and an appropriate charge transfer catalyst in order to create polyethylene glycol chains around the periphery of the graphene perforations.
  • a reaction scheme can be conducted under substantially anhydrous conditions.
  • the moiety in the flow can catalyze the reaction with a polymer substrate (e.g., upon which the graphene-based material or other two-dimensional material is placed following transfer from its growth substrate), which can be considered a subset of the foregoing embodiments.
  • priming the graphene- based material can involve casting a porous substrate, such as a polymer substrate, onto the graphene-based material when it is on its copper growth substrate.
  • the copper can then be etched away.
  • the porous substrate can be exposed to light or some other form of electromagnetic radiation to cause a change in the substance, thereby making it no longer permeable.
  • the porous substrate can be exposed to a compound that binds to the porous substrate.
  • the porous substrate can maintain its porosity when practicing the embodiments described herein.
  • carbonaceous or non-carbonaceous materials can be flowed over the graphene based material or other two-dimensional material and become tethered to the open apertures.
  • Suitable materials can include, for example, graphene nanoplatelets (G Ps), fullerenes of various sizes, hexagonal, boron nitride, or carbon nanotubes.
  • tethering of the carbonaceous or non-carbonaceous material can be accomplished by utilizing a light or gentle ion beam, a high temperature annealing step, exposing to light to generate a photo-active reaction.
  • the high temperature annealing step could comprise isocyanate crosslink chemistry.
  • FIGURE 4 shows an illustrative schematic demonstrating how a perforated graphene sheet or sheet of another two-dimensional material can undergo occlusion with a carbonaceous material or a non-carbonaceous material in the presence of a light ion beam or a high temperature annealing step.
  • the carbonaceous or non-carbonaceous materials are flowed laterally across the sheet of graphene-based material or other two-dimensional material, rather than passing through the apertures.
  • carbonaceous materials or non-carbonaceous materials can be flowed through the sheet of graphene-based material or other two-dimensional material.
  • layered sheets of graphene-based materials or other two-dimensional material can be leveraged to allow for flow not only through channels, but also via intralayer flow. Healing or partial occlusion can result from further modification of apertures. That is, layered sheets of two-dimensional material can be differentially
  • FIG. 3 shows an illustrative schematic demonstrating how a perforated graphene sheet or sheet of another two-dimensional material can undergo occlusion by flowing a catalyst there through.
  • FIG. 4 shows an illustrative schematic demonstrating how a perforated graphene sheet or sheet of another two-dimensional material can undergo occlusion with a carbonaceous material or a non-carbonaceous material in the presence of a light ion beam, or a high temperature annealing step.
  • FIG. 5 shows an illustrative schematic demonstrating how apertures in multiple layered graphene sheets or sheets of other two-dimensional materials can become differentially occluded.
  • the functionalization can be chosen such that apertures of different sizes are occluded in the various graphene sheets.
  • the present disclosure is directed, in part, to composite membranes formed from a porous substrate having a plurality of pores with a sheet of two-dimensional material disposed on the surface of the porous substrate and defining a top surface of the composite membrane.
  • a portion of the pores of the substrate are covered by the two-dimensional material and a portion of the pores of the substrate are not covered by the two-dimensional material due, for example, to defects formed during synthesis of the two-dimensional material, formed during handling of the two-dimensional material, or formed when the two-dimensional material is disposed on the porous substrate. Defects or apertures in the two-dimensional material can result in undesired passage of species through the composite membrane. It is desired for use in filtration
  • substantially all of the substrate pores are covered by the two-dimensional material so that passage through the membrane is primarily controlled by passage through the two-dimensional material.
  • substantially all pores of the substrate are covered by a two-dimensional material that contains perforations of a desired size range for selective passage through the membrane.
  • perforations in the two- dimensional material have a selected chemistry at the perforation as discussed above.
  • the perforation in the two-dimensional material can have selected size or selected size range and discussed above.
  • the two-dimensional material is a graphene-based material.
  • the two-dimensional material is a graphene-based material which comprises single-layer graphene or multi-layer graphene.
  • the disclosure provides methods for occluding uncovered substrate pores in the composite membrane as described above.
  • the method includes introducing one or more occluding moieties at least partially into at least one uncovered pore to occlude the at least one uncovered pore.
  • 50% or more of the uncovered substrate pores are occluded.
  • 60% or more, 75% or more, 80% or more, 90% or more, 95% or more or 99% or more of the uncovered substrate pores are occluded.
  • occlusion of uncovered pores reduced flow through the composite membrane (compared to the non-occlude membrane) by 50% or more.
  • occlusion of uncovered pores reduced flow through the composite membrane (compared to the non-occluded membrane) by 60% or more, 75% or more, 80% or more, 90% or more, 95% or more or 99% or more.
  • the extent of occlusion of uncovered pores can be assessed by various methods. Detection of uncovered pores can, for example, be assessed using a selected assay fluid, e.g., a detectible gas, such as SF 6 , to detect the location (or approximate location) of uncovered pores by passage of the assay fluid. Uncovered pores may be detected by use of the passage of detectible chemical species, particles, electrons, UV or visible light through the pores. The presence of uncovered pores can also be detected by various imaging methods.
  • a selected assay fluid e.g., a detectible gas, such as SF 6
  • Uncovered pores may be detected by use of the passage of detectible chemical species, particles, electrons, UV or visible light through the pores.
  • the presence of uncovered pores can also be detected by various imaging methods.
  • the presence and or location (or approximate location) of pores can be assessed using various imaging methods (including scanning electron microscopy, scanning probe microscopy, scanning tunneling microscopy, atomic force microscopy, transmission electron microscopy, x-ray spectroscopy, etc.); detecting analyte, particles or ions passing through pores (using mass spectrometry, secondary mass spectrometry, Raman spectroscopy, residual gas analysis, detecting Auger electrons, detecting nanoparticles using a microbalance, detecting charged species with a Faraday cup, detecting secondary electrons, detecting movement of analyte through defects, employing an analyte detector, identifying a composition, mass, average radius, charge or size of an analyte; detecting electromagnetic radiation passing through defects;
  • Uncovered substrate pores include those pores that are only partially covered, but through which non-selective passage can occur.
  • the porous substrate of the composite membrane can be any porous material compatible with a disposed two-dimensional material and particularly with a graphene-based material.
  • the porous substrate is selected to be compatible with the application for which the composite membrane is intended. For example, compatible with the gases, liquids or other components which are to be in contact with the composite membrane.
  • the porous substrate provides mechanical support for the two-dimensional material and must maintain this support during use.
  • the porous support should substantially retain pores that are covered with two- dimensional material.
  • the porous material is made of a polymer, metal glass, or a ceramic
  • the pores in the substrate can have uniform pore diameter along the length of the pore, or they can have a diameter that varies along this length. Pores or pore openings (entrance or exit) can be shaped, as discussed below, to facilitate retention of occluding moieties in uncovered pores. Pores may be tapered, ridged or provided with one or more ledges to facilitate retention of occluding moieties in uncovered pores. In a specific embodiment, the pore entrance and/or the pore exit is narrowed compared to the rest of the pore to facilitate retention of occluding moieties. In some embodiments, pores in the substrate are preferably of uniform size and uniform density (e.g., uniformly spaced along the substrate).
  • pores may be independent or may be interconnected with other pores (tortuous or patterend).
  • pores sizes e.g. diameters
  • a top surface of the membrane is defined as the surface upon which the two-dimensional material is disposed.
  • One surface contains pore entrance openings and the second surface contains pore exit openings.
  • Introduction of occluding moieties is through pore entry openings so that introduction of such moieties is selectively into pores that are not covered by two-dimension materials.
  • Pore entrance and exits are defined by flow direction through pores.
  • Occluding moieties most generally include any material that can be selectively introduced into uncovered pores and retained therein to occlude the pore.
  • a step of chemical reaction, application of energy in the form of heat, electromagnetic radiation (e.g., UV, visible or microwave irradiation), or contact with an absorbable material can be applied to deform, swell, polymerize, cross-link or otherwise facilitate retention of occluding materials in a pore.
  • the occluding materials are one or more particles sized for entrance at least in part into an uncovered pore. Particle size and pore shape may be selected to facilitate retention in the uncovered pores.
  • Particles may be deformable, for example, by application of pressure, heat, microwave radiation or light of a selected wavelength (e.g. UV light), or by ion bombardment. Deformable particles introduced into pores are retained in pores after deformation. Particles may be swellable, where the size of a particle increases on contact with an absorbable material which induces swelling.
  • the absorbable material can, for example, be a fluid including liquids or gases, water or an aqueous solution or a miscible mixture of water and an organic solvent, a polar organic solvent or a non-polar organic solvent. The swellable particle and the absorbable fluid are selected to achieve a desired level of swelling to achieve retention in the pore.
  • Occluding particles can be made of any suitable material.
  • particles are made of melamine, polystyrene or polymethyl methacrylate (PMMA).
  • PMMA polymethyl methacrylate
  • the particles are made of latex (polystyrene).
  • the substrate pore occluding particles are themselves permeable to provide a selective permeability through the occluded pores.
  • the substrate pore occluding particles are permeable to fluid flow and provide for separation of components in the fluid.
  • Permeable materials could include hydrogels, polymers, proteins, zeolites, metal-organic framework materials, or thin film solution membranes.
  • Particle size is generally selected based on the pores sizes present in the substrate so that the particle can enter the pore and be retained in the pore. Particles may be monodisperse if the pore entrance openings are uniform in size. A mixture of particles of different sizes can be employed when pore openings are non-uniform in size. A mixture of particles of different sizes (having a selected particle size distribution or being polydisperse in size) can be used, if pores with different (or unknown sizes) are present in the substrate. In an embodiment, the occluding particle is selected to have particle size that is approximately the same size as a pore entrance opening.
  • the occluding particle may be slightly larger for tapered pores and slightly smaller for non-tapered pores such that the pores have a larger cross-section on the side of the substrate exposed to upstream flow.
  • particles are sized for at least partial introduction into an uncovered pore, but wherein the particle cannot exit the uncovered pore. Exit from the pore can be inhibited or prevented by providing shaped pores in which the pores are narrowed at some point along its length.
  • Particles useful in the methods herein will in an embodiment range in size from 10 nm to 10 microns.
  • occlusion may be facilitated through controlled fouling, where a fluid is flowed to the composite membrane surface, and material from the fluid is bonded to composite membrane pores that are defective. The fouling may be controlled such that it blocks non-selective pores.
  • occlusion may be facilitated through healing with particles in air or gas.
  • Particles are aerosolized and/or suspended in air and then forced through the membrane, such as by having convective flow of the air through the membrane.
  • the convective flow of the air could be facilitated by applying a pressure differential across the membrane.
  • the particles could be those described herein, with the methods described herein for fixing the particles to the membrane.
  • occluding particles carry one or more chemical reactive groups for reaction with compatible reactive groups in the at least one uncovered pore, on the surface of the substrate at the uncovered pore or on other particles to facilitate anchoring of at least one particle in at least one uncovered pore.
  • the particles can carry any one or more of a reactive chemical species, for example, the reactive species may be an amine, a carboxylate acid, an activated ester, a thiol, an aldehyde or a hydroxyl group.
  • Particles useful in the concepts disclosed herein which carry reactive groups can be prepared by known methods or may be obtained from commercial sources.
  • Reactive groups on the particles can react with compatible reactive groups on the surface of the substrate at an uncovered pore, within the pore or at pore openings to facilitate retention in the pore.
  • particles may react with other particles in the pore to facilitate retention in the pore.
  • One of ordinary skill in the art can employ a variety of chemically reactive groups to facilitate reaction with a pore to facilitate retention and anchoring in the pore. It will be appreciated that chemical reaction between particles, between particles and the pore surface, edges, openings or exits can be activated or induced by introduction of a reactive species, reagent or catalyst into a pore containing at least one occluding particle.
  • a chemical reaction between particles, between particles and the pore surface, edges, openings or exits can be activated or induced, for example, by heating, microwave irradiation, irradiation with light of selective wavelength (e.g., UV radiation) or by application of an ion beam, or by any method known in the art that is compatible with the materials employed.
  • the occluding moieties are selected from one or more monomers, oligomers, uncured polymers or uncross-linked polymers. These occluding moieties are introduced selectively into uncovered pores and wherein the monomers, oligomers or polymers are polymerized, cured or cross-linked after they are introduced into the at least one uncovered pore. Polymerization can be effected for example by introduction of a polymerization catalyst, heating, microwave irradiation, or irradiation with light of a selected wavelength or by any method known in the art that is compatible with the materials employed.
  • Curing of an uncured polymer or cross-linking of a polymer can be effected by any art-known method, for example by introduction of a curing or cross-linking reagent or application of heating, microwave irradiation, or irradiation with light of a selected wavelength or by any method known in the art that is compatible with the materials employed.
  • the occlusion method further comprising a second step of introducing secondary particles into the at least one uncovered pore having a first particle therein occluding the uncovered pore, where the secondary particles are sized to be smaller than the first particle.
  • the initial particle and the secondary particles may be deformable or swellable as described above and may be deformed or swollen after introduction of the secondary particles.
  • the initial particle and the secondary particles may carry one or more reactive groups as described above for chemical reaction of particles in the pores to facilitate retention in the pore.
  • the composite membrane further comprises a coating layer on the top surface of the porous substrate between that surface and the sheet of two-dimensional material. Chemical reaction of a particle or other occluding moiety with reactive species on this coating at the entrance of the uncovered pore can facilitate anchoring and retention in the pore.
  • Occluding moieties are introduced to the top surface of the composite membrane where the occluding moieties can enter uncovered substrate pores.
  • Introduction can be by any appropriate method and preferably is by application of a flow of fluid containing a selected concentration of occluding moieties.
  • the fluid is an aqueous solution carrying a selected concentration of occluding moieties.
  • concentration of occluding moieties in the flow introduced can be readily optimized empirically to optimize the
  • the flow of occluding moieties includes a surfactant to decrease or minimize clumping or aggregation of occluding moieties and to facilitate entry of occluding moieties into uncovered pores.
  • the inclusion of an appropriate surfactant is particularly beneficial for the introduction of occluding particles.
  • the surfactant is a non-ionic surfactant, such as
  • introduction of occluding moieties to the top surface of the composite membrane is by application of a cross-flow to the surface.
  • the velocity of the cross-flow can be varied according to desired results.
  • the pressure and flow may be varied as desired.
  • the shear velocity of the flow may be controlled.
  • the pressure across the composite membrane may be stopped while shear flowing.
  • the pressure on both sides of the membrane may be equalized.
  • the pressure may be controlled in cycles to alternately provide flow forward and then backward.
  • the pressure on one or both sides of the membrane may be pulsed. Further, peristaltic pump rate and dimensions of the channel through the composite membrane may be controlled according to embodiments.
  • the pore occlusion method further comprising a step of cleaning the top surface after introduction of occluding moieties into uncovered pores to remove occluding moieties that have not entered uncovered pores.
  • This cleaning step can comprise flow of an appropriate fluid (gas or liquid) to or across the top surface of the membrane.
  • a flow of water or an aqueous solution is applied to or across the top surface of the membrane.
  • the aqueous solution contains a surfactant (as discussed above) to decrease clumping or aggregation of particles on the top surface.
  • the introduction and cleaning steps as well any intervening steps to facilitate retention of particles in uncovered pores are repeated until additional occlusion of pores ends or until a selected level of uncovered pore occlusion is achieved.
  • various methods for accessing the extent or efficiency of pore occlusion can be employed.
  • cycles of introduction and cleaning can be repeated until at least 80% of the uncovered pores are occluded. In an embodiment, cycles of introduction and cleaning can be repeated until at least 95% of the uncovered pores are occluded. In an embodiment, cycles of introduction and cleaning can be repeated until at least 99% of the uncovered pores are occluded.
  • the two-dimensional material is a graphene-based material.
  • the two-dimensional materials is a sheet of graphene containing single layer graphene, few layer graphene (having 2-20 layers) or multilayer graphene.
  • the pore occlusion method can be practiced without introducing an occluding moiety into uncovered pores.
  • a composite membrane as discussed above wherein a sheet of two-dimensional material covers at least a portion of the pores of the substrate; but wherein at least one pore of the substrate is not covered by the two-dimensional material.
  • the substrate material forming the pores comprises a swellable material.
  • the substrate itself may be made of a swellable material or more preferably the substrate material surrounding the pores is formed of a swellable material.
  • a coating of swellable material can be applied to the inside surfaces of the substrate pores. Selective introduction of an absorbable material into the uncovered pores results in local swelling of the swellable material surrounding the uncovered pore and occlusion of the uncovered pore.
  • the uncovered pores are selectively contacted with an absorbable fluid.
  • the disclosure further provides a composite membrane comprising a porous substrate having a plurality of pores and a sheet of two-dimensional material disposed on a surface of the porous substrate and defining a top surface of the membrane, wherein the sheet of two - dimensional material covers at least a portion of the pores of the substrate, wherein at least one pore of the substrate is not covered by the two-dimensional material and wherein at least one uncovered pore of the substrate is occluded with an occluding moiety.
  • the composite membrane has at least one uncovered pore occluded with one or more particles or occluded with a polymer, cured polymer or cross-linked polymer formed in the at least one uncovered pore.
  • FIG. 6 schematically illustrates occlusion of uncovered pores in the substrate of a composite membrane having a graphene-based material sheet disposed upon a porous substrate forming a top surface thereof.
  • the occluding moiety is illustrated as a particle.
  • a particle, size- selected based on pore size, to at least partially enter an uncovered pore is illustrated.
  • a plurality of particles are introduced to the top surface of the membrane and a portion of the particles enter and are retained in the uncovered pores.
  • a particle enters at least one uncovered pore and occludes the pore preventing passage though the occluded pore.
  • the substrate may be pre-wetted in some embodiments.
  • FIG. 7 schematically illustrates an exemplary occlusion method applied to a composite membrane having a graphene-based material sheet disposed upon a porous substrate where the substrate pores of the membrane are tapered such that the pores have a larger cross- section on the side of the substrate exposed to upstream flow to facilitate retention of the occluding material and anchoring of the occluding material in the uncovered pore.
  • This embodiment is exemplified with an occluding particle which is size-selected to enter an uncovered pore and is inhibited or prevented from exiting the pore by tapering of the pore.
  • the substrate pores can be variously shaped to facilitate retention of occluding moieties, particularly particles.
  • the direction of particle flow is illustrated as perpendicular to the membrane top surface. It will be appreciated that cross-flow parallel to the top surface can be applied to introduce occluding moieties to the top surface.
  • FIG. 8 schematically illustrates another exemplary occlusion method where the composite membrane has a graphene-based material sheet disposed upon a porous substrate where the substrate pores are tapered to facilitate retention of the occluding material and anchoring of the occluding material in the uncovered pore.
  • an initial particle is introduced into the uncovered pore to occlude the pore and secondary particles of size smaller than the initial particle are introduced into the uncovered occluded pores to facilitate anchoring.
  • FIG. 9 schematically illustrates another exemplary occlusion method applied to composite membranes having a graphene-based material sheet disposed upon a porous substrate.
  • the substrate pores are exemplified as having a ledge or other form of narrowing along their length and specifically at the pore exit to facilitate retention and anchoring of an occluding moiety (exemplified as a particle) in the uncovered pore.
  • the particle may be inserted into the pore, and then a ridge may be formed after the particle is inserted.
  • FIG. 10 schematically illustrates another exemplary occlusion of uncovered substrate pores in a composite membrane having a graphene-based material sheet disposed upon the porous substrate. Pores in the substrate are illustrated as being partially interconnected and nonuniform in diameter, and may form a tortuous path through the substrate. Pores are shown as occluded by introduction of a plurality of particles. It is to be noted that if pore connections exist between covered and uncovered pores that occlusion of uncovered pores may reduce desired flow through covered pores.
  • FIG. 11 schematically illustrates another exemplary occlusion of uncovered pores in a composite membrane having a graphene-based material sheet disposed upon a porous substrate.
  • the substrate pores are illustrated as having a ledge or other form of narrowing at both the entrance and exit from the pores.
  • the particle is swellable, such that the non-swollen particle is of a size that will enter the uncovered pore, but which on swelling is of a size that will not exit the uncovered pore.
  • the swellable particle is composed at least in part of a swellable polymer. More specifically, the swellable particle is composed at least in part of a swellable amorphous polymer.
  • the swellable particle is composed at least in part of a hydrogel.
  • Swelling ratios of swellable polymers and hydrogel can be adjusted by variation of composition of the polymer or hydrogel as is known in the art. Swelling can for example be initiated on contact with an absorbable fluid, such as water or an organic solvent.
  • a hydrogel can be swollen employing absorption of water or aqueous solution.
  • a non-polar or hydrophobic polymer can be swollen with a hydrocarbon solvent.
  • a polar or hydrophilic polymer can be swollen with water or alcohol or mixtures thereof.
  • occluding particles can optionally be provided with one or more reactive groups as discussed above which can react or can be activated to react with compatible chemical moieties in the pores, at the edges of the pores, at the substrate surface at the pore opening or pore exit or disposed on ledges or other structures within the pores. Such chemical reactions facilitate anchoring of the particle in the pore.
  • occluding particles can be provided with compatible reactive chemical groups for reactions between particles in a pore.
  • FIG. 12 schematically illustrates another exemplary occlusion of uncovered pores in a composite membrane having a graphene-based material sheet disposed upon a porous substrate.
  • no occluding moiety is introduced into the uncovered pore.
  • the substrate material itself is swellable, on contact for example with an absorbable fluid. Swelling of the substrate material surrounding the uncovered pore results in occlusion of the pore.
  • the substrate is not made entirely of a swellable material, but the inside surface of the pores of the substrate are provided with a coating that is swellable.
  • FIG. 13 schematically illustrates another exemplary occlusion of uncovered pores in a composite membrane having a graphene-based material sheet disposed upon a surface of a porous substrate.
  • the substrate pore is shown as having a narrowing of the pore diameter at the pore exit.
  • a chemical reaction is activated to anchor the particle at the pore exit. Activation in this case is introduced to the surface of the membrane without the graphene-based material (also designated the backside of the membrane).
  • a chemical reaction can be activated variously, by providing a reagent or catalyst or by providing activating energy, such as heat, light or activating ions or particles.
  • FIGs. 14A and 14B schematically illustrates another exemplary occlusion of uncovered pores in a composite membrane having a graphene-based material sheet disposed upon a porous substrate.
  • the substrate pore is shown in FIGs. 14A and B as having a narrowing of the pore diameter at the pore exit.
  • the occluding particle may be sensitive to applied energy, such as light of selected wavelengths, or contact with electron or ion beams.
  • the applied energy facilitates deformation of the particle in the uncovered pore facilitating anchoring of the particle in the pore.
  • FIGs. 15A and B schematically illustrate another exemplary occlusion of uncovered pores in a composite membrane having a graphene-based material sheet disposed upon a porous substrate.
  • the substrate pore is shown as having a narrowing of the pore diameter at the pore exit.
  • a plurality of particles is shown as introduced into the uncovered pore.
  • the particles and/or the pore surfaces or edges carry reactive chemical groups.
  • FIG. 15A and B schematically illustrate another exemplary occlusion of uncovered pores in a composite membrane having a graphene-based material sheet disposed upon a porous substrate.
  • the substrate pore is shown as having a narrowing of the pore diameter at the pore exit.
  • a plurality of particles is shown as introduced into the uncovered pore.
  • the particles and/or the pore surfaces or edges carry reactive chemical groups.
  • FIG. 15 A energy, for example in the form of light of selected wavelength, an electron or ion beam, or a chemical reagent is applied to the bottom side of the composite membrane to activate chemical reactions between particles and/or between particles and the pores surfaces or edges to facilitate anchoring of particle in the uncovered pore.
  • FIG. 15B where the particles are anchored in the substrate pore
  • FIG. 16 schematically illustrates steps in an exemplary uncovered pore occlusion process.
  • a graphene sheet is disposed on a porous substrate, illustrated with uniform pores, to form a composite membrane. A portion of the pores are covered by the graphene and a portion of the pores are not covered by the graphene (uncovered pores).
  • Particles sized to at least partially enter an uncovered pore are introduced to the top surface of the composite membrane where they enter uncovered pores, but not covered pores.
  • pressure, heat, or light or alternatively solvent swelling is applied to the particles in the uncovered pores to deform the particles or swell the particles to occlude the pores. Particles do not bond to the graphene.
  • the particles are optionally subjected to an optional curing step after deformation.
  • the curing step is for example a thermoset cure achieved by heating.
  • An alternative exemplary cure is achieved catalytically by exposure to a catalyst or curing agent.
  • a cleaning step is then applied to wash off and remove excess particles. The steps of introducing the particles, application of pressure, energy or solvent swelling, and cleaning are repeated until a desired level of pore occlusion is obtained.
  • FIG. 17 schematically illustrates steps in an exemplary uncovered pore occlusion process.
  • a porous substrate is provided with a coating which is compatible with graphene and may enhance adhesion to graphene.
  • the coating provided does not occlude substrate pores.
  • a graphene sheet is then disposed on the coated porous substrate, illustrated with uniform pores to form a composite membrane. A portion of the pores are covered by the graphene and a portion of the pores are not covered by the graphene (uncovered pores). Particles sized to at least partially enter an uncovered pores are introduced to the top surface of the composite member where they enter uncovered pores, but not covered pores.
  • particles optionally bond to the substrate or to the coating on the substrate to facilitate anchoring of the particles to occlude uncovered pores. Particles do not bond to the graphene.
  • the particles may be subjected to an optional curing step after bonding. A cleaning step is then applied to wash off and remove excess particles. The steps of introducing the particles, bonding and optionally curing of particles, and cleaning are repeated until a desired level of pore occlusion is obtained.
  • FIG. 18 schematically illustrates steps in an exemplary uncovered pore occlusion process.
  • a graphene sheet is disposed on a porous substrate, illustrated with uniform pores to form a composite membrane. A portion of the pores are covered with the graphene and a portion of the pores are not covered by the graphene (uncovered pores).
  • Polymerizable monomers or oligomers or a curable or cross-linkable polymer are introduced into the uncovered pores. These precursors do not enter graphene covered pores. The precursors are polymerized, cured or cross- linked within the uncovered pores to occlude the pores. Polymerization or curing can be facilitated by application of heat, light of selected wavelength or of chemical reagents including polymerization catalyst and/or cross-linking agents.
  • a cleaning step is then applied to wash off and remove excess unreacted precursors and any catalysts or reagents employed.
  • the steps of introducing precursors for polymerization, curing or cross-linking, polymerization, curing and /or cross linking and cleaning are repeated until a desired level of pore occlusion is obtained.
  • FIG. 19 schematically illustrates exemplary results of occlusion of uncovered pores as in the process of FIG. 18.
  • the substrate pores are shown as having uniform diameter along their length. Shaped pores can also be employed.
  • the illustrated embodiment shows the formation of a cured material or polymer within the uncovered pore to occlude the pore.
  • the direction of flow for introduction of occluding moieties is illustrated as flow perpendicular to the substrate top surface. It will be appreciated that flow can also be applied in the illustrated embodiments in a cross-flow configuration, where flow is parallel to the substrate top surface.
  • FIGs. 20A and 20B are scanning electron microscopy (SEM) images illustrating latex bead healing (occlusion) of uncovered pores in a composite membrane.
  • SEM scanning electron microscopy
  • the SEM images were taken while tilted at 35-degrees relative to normal of the substrate surface. Areas covered in graphene are dark gray and areas without graphene coverage are light gray.
  • FIG. 20A is a lower magnification (x2500) SEM image showing areas on the composite membrane that are covered or not covered by graphene. Substrate pores (450 nm diameter) which are uncovered by graphene are being occluded by latex beads. Latex beads are also shown clumping on the surface of the composite membrane. Latex beads do not damage the graphene.
  • FIG. 20B is a higher magnification SEM image (x8500) of the same composite membrane showing latex beads occluding uncovered pores in the substrate. Those latex beads which are occluding substrate pores are visible embedded at varying depths into the substrate pores.
  • FIGs.21 A and 21B are SEM images illustrating the progress of latex bead healing (occlusion) of uncovered pores in a composite membrane. Latex beads of particle size 0.46 ⁇ were employed to occlude substrate pores of 0.45 ⁇ . The graphene sheet is light gray and a large area of dark gray is a microdefect in the graphene. A number of apertures in the graphene are circled in the images.
  • FIG. 21 A is an image taken after 5 cycles of alternating latex bead introduction and cleaning, both via cross-flow across the membrane surface. Latex beads were introduced at a lppm dilution in DI water containing 0.1% polysorbate-80 and a biocide (50ppm NaI3).
  • FIG. 2 IB is an image taken after another 4 of alternating latex bead introduction and cleaning (a total of 9 cycles). Additional apertures are occluded in this second image including all of the apertures circled in the image. The occlusion process illustrated in these images was found however not to be optimized.
  • FIG. 22B is a SEM image showing occlusion of 1250nm diameter pores in a silicon nitride substrate by a single graphene sheet
  • FIG. 22C is a SEM image of occlusion of 1250nm diameter pores in a silicon nitride substrate after subsequent application of a second sheet of graphene.
  • a majority of uncovered pores resulting from defects in the first graphene sheet are subsequently occluded by the second graphene sheet.
  • layering of individual sheets of the two-dimensional material is an effective method for occluding pores in a composite membrane that arise from intrinsic or native defects and defects generated during the processing and handling of the two-dimensional material.
  • Occlusion of the substrate pores can be significantly improved when subsequent sheets of the two dimensional material are applied, because the intrinsic or native defects and defects generated during processing and handling are independent for each layer thus the probability of an unoccluded substrate pore is exponentially reduced with each successive layer.
  • Such a method is most effective for fabrication of a size- selective composite membrane when the size-selected perforations are introduced to the multilayer stack of two-dimensional materials.
  • the methods described herein for occluding apertures in a sheet of a two-dimensional material may then be beneficially employed to a multi-layer stack of two dimensional materials.
  • FIG. 22A is a graph of flow rate ( ⁇ 7 ⁇ ) (left axis, diamonds) and cumulative permeate (right axis, squares) as a function of time through a graphene coated composite membrane that is being subjected to uncovered pore occlusion employing latex particles.
  • the y-axis in FIG. 22A corresponds to the flow rates through the membrane (input-to-permeate).
  • the flow rates noted are the cross-membrane (input-to-output) rates, while the pressures noted are the pressure difference between graphene side of membrane and the permeate outlet.
  • the flows that are cross-membrane (input-to-output) are labeled as "x-flow" in FIG.
  • the occlusion process employed to obtain the illustrated results differed from that illustrated in FIGs. 21 A and 21B, in that the concentration of particles applied to the top surface was optimized to improve efficiency of occlusion.
  • the porous substrate of the composite membrane is etched silicon nitride in a rigid silicon support.
  • the silicon nitride has a plurality of patterned 0.45 ⁇ pores.
  • the composite membrane is assessed in a cross-flow arrangement with pressure applied as indicated.
  • An occlusion cycle includes a step of introduction of latex beads (0.46 ⁇ beads) and a subsequent cleaning step.
  • the latex beads are carried in aqueous solution at a concentration of 0.5 ppm (0.1% polysorbate-80 and biocide (50 ppm NaI3) and introduced in cross-flow to the composite membrane at 20 mL/min at 45 psi.
  • the cleaning step is cross-flow application of an aqueous solution containing surfactant at a 20mL/min flow at 0 psi to remove latex beads remaining on surface.
  • the occlusion step and cleaning step are applied for 7-11 minutes as indicated in FIG. 22 A.
  • the figure follows flow rate and cumulative permeate for three full occlusion/cleaning cycles.
  • Introduction of latex beads in the first occlusion step is shown to produce an immediate greater than 99% reduction in flow rate.
  • Cleaning steps induce a small flow rate recovery ( ⁇ 5% of the flow rate before occlusion), which is then reversed by subsequent occlusion steps.
  • the concentration of beads may set according to the desired result.
  • small beads may be introduced, while larger beads are used to remove the small beads in the cleaning step.
  • the agglomerated beads may provide a filtering function.
  • Some embodiments provided herein are cross-linked graphene platelet polymers, compositions thereof, filtration devices comprising the cross-linked graphene platelet polymers and/or compositions thereof and methods for using and making the same.
  • Some of the polymers described herein comprise a graphene portion or moiety and a crosslinking portion or moiety.
  • the graphene portion or moiety may be a graphene platelet that may be chemically bound directly or indirectly to one or more crosslinking portions or moieties.
  • Crosslinking may be by covalent or other bonding mechanism such as ionic, van der Waals, etc.
  • the graphene portion in some embodiments comprises a reacted graphene platelet.
  • the graphene platelet may have a very thin but wide aspect ratio.
  • the graphene platelet may comprise several sheets of graphene, for example 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 sheets of graphene. It is understood that the various sheets are not necessarily the same width, e.g., one or more of the sheets may be a partial sheet that covers only a portion of the sheet in which it is associated with or in contact. For example, a partial sheet may cover about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 98%, 99% of the portion of the sheet in which it is associated with or in contact.
  • the particle diameter of the graphene platelet may range from sub-micron (for example, about 10 nm, 50 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, or 1000 nm) up to about 100 microns (for example up to about 1 micron, 2 microns, 3 microns, 4 microns, 5 microns, 6 microns, 7 microns, 8 microns, 9 microns, 10 microns, 20 microns, 30 microns, 40 microns, 50 microns, 60 microns, 70 microns, 80 microns, 90 microns, 100 microns).
  • the graphene platelets will not necessarily be perfect circular particles.
  • the particle diameter may be measured from the widest points of the graphene platelet.
  • the size of the graphene platelets may also be expressed as an average size or a plurality of graphene platelets.
  • the average size of a plurality of graphene platelets used may be about 10 nm, 50 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, or 1000 nm, about 100 microns (for example up to about 1 micron, 2 microns, 3 microns, 4 microns, 5 microns, 6 microns, 7 microns, 8 microns, 9 microns, 10 microns, 20 microns, 30 microns, 40 microns, 50 microns, 60 microns, 70 microns, 80 microns, 90 microns, 100 microns.
  • the coefficient of variation for the average size may be greater than zero to about 25%. For example, the coefficient of variation may be about 0.0
  • the graphene platelets in some of the embodiments may be functionalized. This functionalization may result in a direct or indirect chemical bond to the one or more crosslinking portions or moieties, or it may provide additional functionality to the resulting cross-linked graphene platelet polymer.
  • the graphene platelet comprises one or more reactive moieties capable of reacting with a crosslinking molecule.
  • the graphene platelet is functionalized as disclosed in Hunt, A., et al. Adv. Funct. Mater., 22(18), pp. 3950-3957, 2012.
  • the one or more reactive moieties may be capable of reacting with a
  • the one or more reactive moieties of the graphene platelet can be an epoxy functional group or amine, and graphene/carbon nitride via reaction in a nitrogen plasma.
  • the one or more reactive moieties is a "capped" moiety that is capable of converting to a reactive moiety upon, e.g., chemical, heat or UV treatment.
  • the graphene has a variable C/O ratio that maximizes the mechanical strength and the variation is C/O ratio of 2/1, 5/1, 10/1, 20/1, 30/1, 40/1, 50/1, 60/1 70/1, 80/1 90/1, and 100/1.
  • the speciation of the graphene would be either hydroxyl or epoxy, when reactions with amines or cyanates, can form one pot epoxy or urethane networks.
  • the one or more reactive moieties are a "capped" moiety that is capable of converting to a reactive moiety upon, e.g., chemical, heat or UV treatment.
  • the graphene platelet may comprise 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 reactive moieties.
  • a plurality of graphene platelets used in the polymer may have an average of about 2, 3, 4, 5, 6, 7, 8, 9 or 10 reactive moieties.
  • the coefficient of variation for this average may be greater than zero to about 25%.
  • the coefficient of variation may be about 0.01, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20.
  • the graphene platelet comprises one or more functional moieties. These moieties are different from the reactive moieties in that they do not react with the crosslinking molecule, but rather they ultimately impart some functionalization to the resulting cross-linked graphene platelet polymer. Some embodiments utilize functional moieties including thiol moieties, fluorocarbon functionalized areas of the graphene platelet and/or phosphorus, silane and siloxane functional groups.
  • the crosslinking portions or moieties in some embodiments may be a crosslinking portion that is chemically bound directly or indirectly to two or more graphene portions or moieties.
  • the cross-linked graphene may form ordered layers wherein the crosslinking moiety controls the spacing between ordered layers.
  • the crosslinking portion comprises a reacted di-, tri- or tetra- functional crosslinking compound.
  • the functional group may be a (meth)acrylate or
  • the di-, tri- or tetra-functional crosslinking compound contains the same functional groups.
  • the functional groups on the di-, tri- or tetra-functional crosslinking compound are different.
  • the crosslinking compound also includes a spacer portion between the functional groups. The spacer group remains in the crosslinking portions or moieties after the functional groups have reacted.
  • the spacer group may comprise 1 to 10 atoms in a linear chain, for example, carbon, oxygen or sulfur atoms, phosphide, phosphate or inorganic moieties as well, silicon and transition metals.
  • the length of the spacer groups will determine the class of the filtered species.
  • the spacer group between adjacent or laterally stacked graphene platelets of 1 to 6 carbons, with a carbon-carbon single bond of 1.54 A, allows for selectivity of ionic filtration, for species up to 1 nm in diameter.
  • Longer spacers, or branching can enable selectivity for viruses and other pathogens.
  • the spacer may be longer, but still provide spacing between graphene platelets that allows for selective size exclusion of certain viruses and other pathogens of a particular size. The spacing may be determined based on the desired viruses and other pathogen that should be excluded.
  • the spacer group is a CI -CI0 linear chain, or a C3-C20 branched chain.
  • the carbons may be replaced by an oxygen and/or sulfur atom.
  • the CI -CI0 linear chain or C3-C20 branched chain may comprise methylene groups, which may be optionally substituted with one or more halogen of hydroxyl group thiol groups, phosphate, or phosphide.
  • the crosslinking portions or moieties of the present disclosure provide a spacing between two or more graphene portions or moieties.
  • the cross-linking portion or moiety provides a 4 to 10 atom link between two or more graphene portions or moieties.
  • the cross-linking portion provides a 4 to 10 atom link between two or more graphene portions or moieties provide a spacing between individual graphene platelet moieties of about 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, or 3.5 nm.
  • the spacing between individual graphene platelet moieties may be determined by molecular modeling of the reacted cross-linking portion, or by microscopic methods, electroacoustic spectroscopy to measure particle and spacing size in aqueous media as well as the zeta potential of the surfaces. Also, x- ray diffraction may be employed to measure inter-plate gallery spacing in lamellar structures. Methods to control the spacing between vertically stacked graphene platelets can employ flexible, e.g., polyphenylene oxide repeat units or rigid carbon spacers with, e.g., polyphenylene or polynorbornene rods to provide a consistent spacer between graphene plates.
  • the crosslinking portions or moieties of the present disclosure can include spacer moieties.
  • the crosslinking portion may include moieties to attach to the graphene platelets (e.g., covalently, ionically, etc.) and the spacer moiety.
  • Spacer substances can include polymers, fibers, hydrogels, molecules, nanostructures, nanoparticles and allotropes that are responsive to an environmental stimulus.
  • the spacer substance is a smart polymer, such as a hygroscopic polymer; a thin polymer that expands when hydrated; or an amorphous polymer, such as a porous amorphous polymer.
  • the spacer substance comprises electrospun fibers that can be swelled upon exposure to a solvent.
  • the spacer substance comprises materials with a high thermal expansion coefficient, which expand or contract in response to a temperature stimulus.
  • the spacer substance is deliquescent.
  • the spacers are substantially inert. In some embodiments, the spacers are not inert (i.e., they can be reactive).
  • Exemplary spacer substances also include structural proteins, collagen, keratin, aromatic amino acids, and polyethylene glycol. Such spacer substances can be responsive to changes in tonicity of the environment surrounding the spacer substance, pi-bonding availability, and/or other environmental stimuli.
  • the spacer substance is a piezoelectric, electrostrictive, or ferroelectric magnetic particle.
  • the magnetic particle comprises a molecular crystal with a dipole associated with the unit cell.
  • the magnetic particles can be oriented based on an external magnetic field.
  • Exemplary magnetic particles include lithium niobate, nanocrystals of 4-dimethylamino-N-methyl-4-stilbazolium tosylate (DAST)), crystalline polytetrafluoroethylene (PTFE), electrospun PTFE, and combinations thereof.
  • the spacer substance heats up faster or slower than its surroundings. Without being bound by theory, it is believed that such embodiments will allow the rate of passage of permeants, or a subset of permeants, across the membrane to be increased and/or decreased.
  • spacer substances respond to electrochemical stimuli.
  • a spacer substance can be an electrochemical material (e.g., lithium ferrophosphate), where a change in oxidation state of the spacer substance (e.g., from 2- to 3-) alters permeability of the membrane.
  • changing the oxidation state of the spacer substances alters the interaction between the spacer substance and potential permeants.
  • the change in oxidation state results from a redox-type reaction. In some embodiments, the change in oxidation state results from a voltage applied to the membrane.
  • the spacer substance comprises contamination structures formed by utilizing a focused ion beam, e.g., to modify heavy levels of contamination on graphene-based material into more rigid structures. For instance, in some embodiments, mobilization and migration of contamination on the surface of the graphene-based material occurs— coupled in some embodiments with some slight beam induced deposition— followed by modification and induced bonding where the beam is applied. In some embodiments, combining contamination structures allows the geometry, thickness, rigidity, and composition of the spacer substance to be tuned to respond to an environmental stimulus (e.g., pressure).
  • an environmental stimulus e.g., pressure
  • Exemplary spacer substance includes particle substances such as metal nanoparticles (e.g., silver nanoparticles), oxide nanoparticles, octadecyltrichlorosilane nanoparticles, carbon nanotubes, and fullerenes.
  • the spacer substance includes nanorods, nano- dots (including decorated nano-dots), nanowires, nanostrands, and lacey carbon materials.
  • the spacer moiety is responsive to an environmental stimulus
  • the spacer substance may expand and/or contracts in response to the environmental stimulus.
  • the spacer substance may reversibly expand and/or reversibly contract in response to the environmental stimulus.
  • conformational changes between trans and cis forms of a spacer substance can alter the effective diameter of the spacer substance (by way of example, a spacer substance could be a polymer with an embedded diazo dye, where exposure to the appropriately colored light alters the volume of the dye based on cis-/trans- conformational changes).
  • the spacer substance undergoes a physical and/or chemical transformation that is pH-modulated or optically modulated.
  • the environmental stimulus degrades the spacer substance to alter the effective diameter of the spacer substance.
  • the environmental stimulus induces a conformational change in the spacer substance that alters the effective length of the spacer substance.
  • Environmental stimuli may include, for example, changes in temperature, pressure, pH, ionic concentration, solute concentration, tonicity, light, voltage, electric fields, magnetic fields, pi-bonding availability, and combinations thereof.
  • the polymers described herein may include additional monomeric components, biocompatible silicone, hexamethyl tnsiloxane (D3), epoxy, both cyclohexyl epoxies, amenable to UV curing, and epichlorohydrin, amenable to substitution on the carbonyl functionality of graphene.
  • the epichlorohydrin may be curable via thermal methods, and provides a durable, cross-linked graphene polymer.
  • Some polymeric cross-linkers initiators may be curing agents, such as diamines.
  • Other monomers and chain spacers may be included, such as aromatic and alkyl di-carboxylic acids curing via the hydroxyl functionality on the graphene platelets to create polyester cured graphene.
  • cross-linked graphene platelet polymers described herein have a sufficient crosslink density to prevent large gaps of uncured section of graphene, which may allow, e.g., salt, to pass unimpeded through greater than about 1 nm holes (or spaces between platelets).
  • the cross-linked graphene platelet polymers have a crosslink density of 0- 0.33 (for example, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, or 0.33, and measured by differential scanning calorimetry.
  • the cross-linked graphene platelet polymer compositions contain less than about 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1% holes (or spaces between platelets) greater than about 1 nm. In some other embodiments, the cross-linked graphene platelet polymer
  • cross-linked graphene platelet polymer composition is substantially free of holes (or spaces between platelets) greater than about 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2 nm.
  • cross-linked graphene platelet polymer composition comprises holes (or spaces between platelets) between 0.5 and 2.0 nm.
  • the space between platelets changes in response to an environmental stimulus as described herein.
  • the space between platelets may be between 0.5 and 2.0 nm after or before the change in response to an environmental stimulus as described herein.
  • the cross-linked graphene platelet polymer composition has a crosslink density sufficient to reduce the sodium content in a 3.5% saline solution by at least 50, 60, 70, 80, 90 or 100 fold when passed through the cross-linked graphene platelet polymer composition having a thickness of about 100 nm.
  • Other embodiments include, e.g., about 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, or 250 nm, or values in between.
  • Figure 23 demonstrates an exemplary reaction scheme of an embodiment of the present disclosure, wherein the graphene platelet comprises a reactive epoxide moiety and the functional crosslinking compounds are di-functional crosslinking compounds containing either hydroxyl moieties or acrylate moieties.
  • the cross-linked graphene platelet comprise one or more functional moieties.
  • the cross-linked graphene platelet polymer compositions may be further functionalized to remove or reduce one or more deleterious contaminant from a liquid or gas passing through the cross-linked graphene platelet polymer composition.
  • the holes (or spaces between platelets) within the cross-linked graphene platelet polymer composition may be patterned with silver nanoclusters that, e.g., deactivate the bacteria.
  • the cross-linked graphene platelet polymer composition may be further treated with quaternary alkyl-ammonium bromide compounds that, e.g., have been shown to coordinate with the phospholipid shell of viruses.
  • the cross-linked graphene platelet polymer composition may include ionically or chemisorbed ammonium compounds that are not covalently bound to the cross-linked graphene platelet polymer.
  • the cross-linked graphene platelet polymer may be formed into membranes that remove or reduce one or more deleterious contaminant from a liquid or gas passing through the cross-linked graphene platelet polymer composition.
  • the liquid is water.
  • the cross-linked graphene platelet polymer compositions may be mounted on a support structure.
  • the cross-linked graphene platelet polymer may be formed into membranes that isolate or concentrate one or more desired components from a liquid or gas passing through the cross-linked graphene platelet polymer composition.
  • desired components e.g., seawater by reducing water content where certain components of the seawater (e.g., water) are capable of passing through the cross-linked graphene platelet polymer composition, but the desired compounds, such as rare earth ions, are incapable of passing through the cross-linked graphene platelet polymer composition.
  • the membranes in some embodiments may include more than one cross-linked graphene platelet polymer composition layers.
  • the different layers may be incorporated into a membrane module, wherein the various layers each has a particular functionality.
  • the filter module comprising at least two separate filters or membranes each comprising a cross-linked graphene platelet polymer composition layer, wherein each filter or membrane is functionalized in a different manner, e.g., wherein the cross- linking moieties generate a spacing of about 1 nanometer between individual graphene platelet moieties, wherein the cross-linking portion contains a 4 to 10 atom link, wherein the cross-linked graphene platelets comprise a thiol moiety, wherein the cross-linked graphene platelets further comprise a metal nanocluster, wherein the cross-linked graphene platelets further comprise a quaternary alkyl-ammonium bromide, or wherein the graphene platelet moieties contains fluorocarbon functionalization.
  • FIG. 24 provides an exemplary configuration of a filter module of an embodiment of the present disclosure.
  • the composite membrane may be used as a separation/barrier layer or for immunoisolation of a second material that is meant to be isolated from an immune response when placed in a biological system (e.g., an animal such as a mammal). For example, it may be used to separate one environment from another within a biological system.
  • a biological system e.g., an animal such as a mammal
  • the spacing between individual graphene platelet moieties may be such that certain biological components are excluded from passing through the composite membrane.
  • the composite membrane may be used in transdermal applications, wherein the spacing between individual graphene platelet moieties may be such that certain biological components are excluded from passing through the composite membrane.
  • the filters and membranes of the disclosure have broad application, including in water filtration, immune-isolation (i.e., protecting substances from an immune reaction), timed drug release (e.g., sustained or delayed release), hemodialysis, and hemofiltration.
  • Some embodiments described herein comprise a method of water filtration, water desalination, water purification, immune-isolation, timed drug release, hemodialysis, or hemofiltration, where the method comprises exposing a membrane to an environmental stimulus, and wherein the membrane comprises a cross-linked graphene platelet polymer described herein.
  • Some embodiments include a method of increasing the purity of a liquid or gas, comprising contacting a first portion of a liquid or gas having an impurity with a filter or membrane comprising the cross-linked graphene platelet polymer compositions to form a second portion of a liquid or gas, wherein the second portion of a liquid or gas contains a lower concentration of the impurity.
  • the liquid or gas is liquid water.
  • the liquid or gas is a liquid in a physiological environment, e.g., in an animal, such as a mammal or human.
  • the impurity is a salt that may be ionized (e.g., NaCl salt or sodium and chloride ions) or a heavy metal or bacteria (or microorganisms, such as viruses) or a hydrocarbon or a larger biological compound such as antibodies (whereas the filter or membrane can allow passage of biological compounds such as insulin, proteins and/or other biological material (e.g., RNA, DNA, and/or nucleic acids))).
  • the second portion of liquid or gas e.g., water
  • the second portion of liquid or gas e.g., water
  • the second portion of liquid or gas e.g., water
  • Some embodiments include a method of concentrating a material of interest from a liquid or gas, comprising contacting a first portion of a liquid or gas having a composition of interest with a filter or membrane comprising the cross-linked graphene platelet polymer compositions to form a second portion of liquid or gas, wherein the second portion of liquid or gas contains a lower concentration of the composition of interest, and collecting the composition of interest that does not pass through the filter or membrane.
  • Some embodiments include a method of concentrating a composition of interest from water by reducing the water content of a solution of that composition.
  • the composition of interest may be a rare- earth element.
  • the cross-linked graphene platelet polymer compositions and filter or membrane may be used as a pre-filtration device.
  • some embodiments include a method of increasing the purity of water, comprising contacting a first portion of water having an impurity with a filter or membrane comprising the cross-linked graphene platelet polymer compositions to form a second portion of water, wherein the second portion of water contains a lower concentration of the impurity, followed by contacting the second portion of water with a perforated graphene filter or membrane.
  • Other embodiments include membranes wherein the spacing between individual graphene platelet moieties is such that is allows certain compounds to pass freely, but retards the passage of other, larger compounds.
  • membranes wherein the spacing and functionalization between individual graphene platelet moieties is such that is allows certain compounds to pass freely, but retards the passage of other compounds that interact with the graphene platelet moieties or a functional compound contained in the cross-linked graphene platelet polymer.
  • a membrane that allows passage of water but excludes salt ions e.g. Na+ and C1-
  • the membrane can be tuned to allow passage of biological compounds such as insulin, proteins and/or other biological material (e.g., RNA, DNA, and/or nucleic acids), but to exclude passage of other larger biological compounds such as antibodies.
  • biological compounds such as insulin, proteins and/or other biological material (e.g., RNA, DNA, and/or nucleic acids)
  • the membrane can be tuned to be permeable to oxygen and nutrients, but to exclude passage of cells (such as immune cells), viruses, bacteria, antibodies, and/or complements of the immune system.
  • the membrane can be tuned from one that allows passage of antibodies to one that inhibits passage of antibodies.
  • Other embodiments include methods of encasing a material and selectively allowing matter of a certain size to contact the encased material.
  • the linked graphene platelet polymer compositions and filters or membranes may be used as encapsulating materials within a biological system, wherein the spacing between individual graphene platelet moieties is such that is allows certain compounds to pass freely, but retards the passage of compounds, such as antibodies from traversing the graphene platelet polymer composition.
  • a membrane that allows passage of water but excludes salt ions can be tuned to allow passage of both water and salt ions.
  • the membrane can be tuned to allow passage of biological compounds such as insulin, proteins and/or other biological material (e.g., RNA, DNA, and/or nucleic acids), but to exclude passage of other larger biological compounds such as antibodies.
  • the membrane can be tuned to be permeable to oxygen and nutrients, but to exclude passage of cells (such as immune cells), viruses, bacteria, antibodies, and/or complements of the immune system.
  • the membrane can be tuned from one that allows passage of antibodies to one that inhibits passage of antibodies.
  • the cross-linked graphene platelet polymers may be formed by reacting one or more functionalized graphene platelets with one or more functionalized crosslinking compounds of the present disclosure.
  • the functionalized graphene platelets of the present disclosure and the functionalized crosslinking compounds of the present disclosure are reacted by heat or radiation (e.g., UV) or e-beam.
  • Methods of some embodiments comprise using graphene-based materials and other two-dimensional materials to transport, deliver, and or separate substances. Some embodiments comprise to enclosures formed from graphene-based materials and other two-dimensional materials on or suspended across a suitable substrate or substrates which can be porous or non- porous, which can serve as a delivery vehicle in an environment external to the enclosure, particularly in a biological environment. Some embodiments comprise enclosures formed from graphene-based materials or other two-dimensional materials containing cells, pharmaceuticals, therapeutic agents and other medicaments.
  • enclosures are configured for long-term in vivo implantation for the delivery of pharmaceuticals, therapeutic agents or other medicaments directly to a biological environment can improve compliance with a dosing regimen relative to traditional oral and intravenous delivery methods that require patient or medical personnel intervention.
  • enclosures may be configured as oral capsules or suppositories.
  • an enclosure may be provided in a gelatin capsule for ease of swallowing.
  • enclosures may be physically coupled with or integrated into a device that ensures contact of the enclosure with the skin of a subject for transdermal drug delivery.
  • a device for ensuring contact between an enclosure and skin may comprise a pocket for receiving the enclosure and microneedles or other relief features for penetrating the stratum cornea and anchoring the device and enclosure to the skin of a subject.
  • a sheath or vascularization device may be provided or surgically placed within a subject and enclosures may be inserted into and removed from the sheath or vascularization device.
  • the sheath or vascularization device may, for example, be tubular and rigid, perforated or permeable, so long as it is capable of withstanding forces provided in an in vivo environment.
  • a sheath or vascularization device is biocompatible.
  • a sheath or vascularization device comprises graphene.
  • Enclosures disposed in a sheath or vascularization device may be exchanged in a minimally invasive manner when their contents are depleted, damaged, or otherwise compromised, or when an enclosure captures an analyte for ex vivo analysis.
  • an interior of an enclosure may comprise a molecule, protein (e.g., antibody), or other substance (e.g., chelating agent) that ionically, covalently or
  • analyte may be bound to an interior surface of an enclosure.
  • enclosures that capture analytes for ex vivo analysis may be used without a sheath or vascularization device. For example, an enclosure for capturing an analyte may be surgically inserted into a subject at a specific site for a period of time, then surgically removed, or an enclosure for capturing an analyte may be ingested and passed through the digestive system.
  • enclosures can be configured to deliver pharmaceuticals, therapeutic agents or other medicaments directly to a biological environment.
  • enclosure are used for treating medical conditions (including chronic medical conditions) requiring a substantially continuous release and/or slow release of a pharmaceutical, therapeutic agent, or other medicament.
  • enclosures elute drugs to a biological environment at a rate that is substantially constant, e.g., in accordance with zero-order kinetics.
  • the enclosures elute drugs with a delayed release profile.
  • implanted or ingested enclosures elute drugs with a delayed release profile.
  • Graphene represents an atomically thin layer of carbon in which the carbon atoms reside as closely spaced atoms at regular lattice positions, and can possess favorable mechanical and electrical properties, including optical properties, thinness, flexibility, strength, conductivity (e.g., for potential electrical stimulation), tunable porosity when perforated, and permeability.
  • the regular lattice positions can have a plurality of defects present therein, which can occur natively or be intentionally introduced to the graphene basal plane. Such defects will also be equivalently referred to herein as "pores,” “apertures,” “perforations,” or “holes.” Aside from such apertures, graphene and other two-dimensional materials can represent an impermeable layer to many substances. Therefore, when sized properly, the apertures in the impermeable layer of such materials can be useful for ingress and egress to an enclosure formed from the impermeable layer.
  • Some embodiments comprise graphene-based enclosures that are capable of delivering a target to an in vivo or in vitro location while maintaining a barrier (e.g., an immunoisolation barrier) in an organism or similar biological environment.
  • a barrier e.g., an immunoisolation barrier
  • Encapsulation of molecules or cells with bi-directional transport across a semi-permeable membrane, such as perforated graphene or other two-dimensional materials, while sequestering cells or the like in a biological environment (such as in an organism) can enable treatments to overcome graft rejection, the need for repeated dosages of drugs (e.g., drugs with short half-lives), and excess surgical intervention.
  • the foregoing can be accomplished by providing technology to allow xenogenic and allogenic tissue transplants, autogenic transplants for subjects with autoimmune disorders, long term low-dose therapeutic levels of a drug, and even sense-response paradigms to treat aliments after surgical intervention, thereby reducing complications from multiple surgeries at the same site.
  • Some embodiments comprise enclosures formed by two-dimensional materials configured for deployment within a tissue or organ, e.g., spanning a space between walls of a tissue or organ.
  • enclosures may be suspended inside or adjacent to an artery or an organ.
  • inlet and outlet ports of an enclosure may be aligned with fluid flow within a blood vessel such that the device is configured in-line or in parallel with the fluid flow.
  • Some embodiments comprise enclosures formed by two-dimensional materials where the enclosure or a compartment thereof comprises at least one opening.
  • a doughnut-shaped or toroid-shaped enclosure comprising an opening can receive vasculature, nerves or nerve bundles, heart valves, bones and the like through the opening, which may anchor or secure the enclosure at a site in need of therapeutic agents contained within the enclosure.
  • Some embodiments comprise enclosures formed by two-dimensional materials, where the enclosure or a component thereof comprises a lumen in the form of a tube or port for introducing or removing cells, pharmaceuticals, therapeutic agents and other substances into/from the enclosure.
  • a lumen, tube, or port can be joined with the two-dimensional material of the enclosure, for example, by physical methods of clamping or crimping and/or chemical methods implementing a sealant (e.g., silicone).
  • the lumen, tube, or port can be joined with an impermeable region (which, e.g., can be non-graphene) that is connected or sealed to the two-dimensional material.
  • a lumen comprises a self-sealing end for receiving the substance via syringe.
  • perforated graphene and other two-dimensional materials can readily facilitate the foregoing while surpassing the performance of current delivery vehicles and devices, including immune-isolating devices.
  • graphene can accomplish the foregoing due to its thinness, flexibility, strength, conductivity (for potential electrical stimulation), tunable porosity, and permeability in the form of perforations therein.
  • the thinness and subsequent transport properties across the graphene membrane surface can allow a disruptive time response to be realized compared to the lengthy diffusion seen with thicker polymeric membranes of comparable size performance.
  • Two-dimensional materials include those which are atomically thin, with thickness from single-layer sub-nanometer thickness to a few nanometers, and which generally have a high surface area.
  • Two-dimensional materials include metal chalogenides (e.g., transition metal dichalogenides), transition metal oxides, hexagonal boron nitride, graphene, silicene and germanene (see: Xu et al. (2013) "Graphene-like Two-Dimensional Materials) Chemical Reviews 113 :3766-3798).
  • Graphene represents a form of carbon in which the carbon atoms reside within a single atomically thin sheet or a few layered sheets (e.g., about 20 or less) of fused six-membered rings forming an extended sp2-hybridized carbon planar lattice.
  • graphene has garnered widespread interest for use in a number of applications, primarily due to its favorable combination of high electrical and thermal conductivity values, good in-plane mechanical strength, and unique optical and electronic properties.
  • Other two- dimensional materials having a thickness of a few nanometers or less and an extended planar lattice are also of interest for various applications.
  • a two dimensional material has a thickness of 0.3 to 1.2 nm or 0.34 to 1.2 nm. In some embodiments, a two dimensional material has a thickness of 0.3 to 3 nm or 0.34 to 3 nm.
  • the two-dimensional material comprises a sheet of a graphene-based material.
  • the sheet of graphene-based material is a sheet of single or multilayer graphene or a sheet comprising a plurality of interconnected single or multilayer graphene domains.
  • the multilayer graphene domains have 2 to 5 layers or 2 to 10 layers.
  • the layer comprising the sheet of graphene- based material further comprises non-graphenic carbon-based material located on the surface of the sheet of graphene-based material. In some embodiments, the amount of non-graphenic carbon-based material is less than the amount of graphene.
  • the amount of graphene in the graphene-based material is from 60% to 95% or from 75% to 100%.
  • the characteristic size of the perforation is from 0.3 to 10 nm, from 1 to 10 nm, from 5 to 10 nm, from 5 to 20 nm, from 5 to 25 nm, from 5 to 30 nm, from 7 to 25 nm, from 7 to 20 nm, from 10 to 25 nm, from 15 to 25 nm, from 10 nm to 50 nm, from 50 nm to 100 nm, from 50 nm to 150 nm, from 100 nm to 200 nm, or from 100 nm to 500 nm.
  • the average pore size is within the specified range. In some embodiments, 70% to 99%, 80% to 99%, 85% to 99% or 90 to 99% of the perforations in a sheet or layer fall within a specified range, but other pores fall outside the specified range.
  • the technique used for forming the graphene or graphene-based material is not believed to be particularly limited, and may be used to form single-layer graphene or graphene- based materials (SLG) or few-layer graphene or graphene-based materials (FLG).
  • CVD graphene or graphene-based material can be used.
  • the CVD graphene or graphene-based material can be liberated from its growth substrate (e.g., Cu) and transferred to a polymer backing.
  • the techniques for introducing perforations to the graphene or graphene-based material are also not believed to be particularly limited, other than being chosen to produce perforations within a desired size range.
  • Perforations are sized to provide desired selective permeability of a species (atom, ion, molecule, DNA, RNA, protein, virus, cell, etc.) for a given application.
  • Selective permeability relates to the propensity of a porous material or a perforated two-dimensional material to allow passage (or transport) of one or more species more readily or faster than other species. Selective permeability allows separation of species which exhibit different passage or transport rates.
  • selective permeability correlates to the dimension or size (e.g., diameter) of apertures and the relative effective size of the species.
  • Selective permeability of the perforations in two-dimensional materials can also depend on functionalization (e.g., of perforations if any, or the surface of the graphene-based material) and the specific species that are to be separated.
  • Selective permeability can also depend on the voltage applied across the membrane. Separation of two or more species in a mixture includes a change in the ratio(s) (weight or molar ratio) of the two or more species in the mixture after passage of the mixture through a perforated two-dimensional material.
  • Graphene-based materials include, but are not limited to, single layer graphene, multilayer graphene or interconnected single or multilayer graphene domains and combinations thereof. In some embodiments, graphene-based materials also include materials which have been formed by stacking single or multilayer graphene sheets. In some embodiments, multilayer graphene includes 2 to 20 layers, 2 to 10 layers or 2 to 5 layers. In some embodiments, graphene is the dominant material in a graphene-based material.
  • a graphene-based material comprises at least 20% graphene, at least 30%> graphene, or at least 40% graphene, or at least 50%) graphene, or at least 60%> graphene, or at least 70% graphene, or at least 80%> graphene, or at least 90% graphene, or at least 95% graphene.
  • a graphene-based material comprises a range of graphene selected from 30% to 95%, or from 40% to 80% from 50% to 70%, from 60% to 95% or from 75% to 100%.
  • a "domain” refers to a region of a material where atoms are uniformly ordered into a crystal lattice.
  • a domain is uniform within its boundaries, but different from a neighboring region.
  • a single crystalline material has a single domain of ordered atoms.
  • at least some of the graphene domains are nanocrystals, having domain size from 1 to 100 nm or 10-100 nm.
  • at least some of the graphene domains have a domain size greater than 100 nm to 1 micron, or from 200 nm to 800 nm, or from 300 nm to 500 nm.
  • Some embodiments comprise a domain size up to about 1 mm.
  • a first crystal lattice may be rotated relative to a second crystal lattice, by rotation about an axis perpendicular to the plane of a sheet, such that the two lattices differ in "crystal lattice orientation".
  • the sheet of graphene-based material comprises a sheet of single or multilayer graphene or a combination thereof.
  • the sheet of graphene-based material is a sheet of single or multilayer graphene or a combination thereof.
  • the sheet of graphene-based material is a sheet comprising a plurality of interconnected single or multilayer graphene domains.
  • the interconnected domains are covalently bonded together to form the sheet. When the domains in a sheet differ in crystal lattice orientation, the sheet is polycrystalline.
  • the thickness of the sheet of graphene-based material is from 0.34 to 10 nm, from 0.34 to 5 nm, or from 0.34 to 3 nm.
  • a sheet of graphene-based material comprises intrinsic or native defects. Intrinsic or native defects are those resulting from preparation of the graphene-based material in contrast to perforations which are selectively introduced into a sheet of graphene-based material or a sheet of graphene. Such intrinsic or native defects include, but are not limited to, lattice anomalies, pores, tears, cracks or wrinkles. Lattice anomalies can include, but are not limited to, carbon rings with other than 6 members (e.g. 5, 7 or 9 membered rings), vacancies, interstitial defects (including incorporation of non-carbon atoms in the lattice), and grain boundaries.
  • the layer comprising the sheet of graphene-based material further comprises non-graphenic carbon-based material located on the surface of the sheet of graphene-based material.
  • the non-graphenic carbon-based material does not possess long range order and may be classified as amorphous.
  • the non-graphenic carbon-based material further comprises elements other than carbon and/or hydrocarbons. Non-carbon elements which may be incorporated in the non-graphenic carbon include, but are not limited to, hydrogen, oxygen, silicon, copper and iron.
  • the non-graphenic carbon-based material comprises hydrocarbons.
  • carbon is the dominant material in non-graphenic carbon-based material.
  • a non-graphenic carbon-based material comprises at least 30% carbon, or at least 40% carbon, or at least 50% carbon, or at least 60% carbon, or at least 70% carbon, or at least 80% carbon, or at least 90% carbon, or at least 95% carbon.
  • a non-graphenic carbon-based material comprises a range of carbon selected from 30% to 95%, or from 40% to 80%, or from 50% to 70%.
  • Nanomaterials that contain pores in its basal plane, regardless of whether they are intrinsically or natively present or intentionally created, will be referred to herein as "perforated two-dimensional materials.”
  • Exemplary perforated two-dimensional materials include perforated graphene-based materials and/or other perforated graphene.
  • the term "perforated graphene-based materials” is used herein to denote a two-dimensional material comprising a graphene sheet with defects in its basal plane, regardless of whether the defects are intrinsically or natively present or intentionally produced.
  • Perforated graphene-based materials include perforated graphene.
  • the perforated two-dimensional material contains a plurality of holes of size (or size range) appropriate for a given enclosure application.
  • the size distribution of holes may be narrow, e.g., limited to a 1-10% + 3% deviation in size, or a 1-20% + 5% deviation in size, or a 1-30% + 5% deviation in size.
  • the characteristic dimension of the holes is selected for the application. For circular holes, the characteristic dimension is the diameter of the hole.
  • the characteristic dimension can be taken as the largest distance spanning the hole, the smallest distance spanning the hole, the average of the largest and smallest distance spanning the hole, or an equivalent diameter based on the in-plane area of the pore.
  • pore geometries or shapes may be implemented in a two-dimensional membrane, such as circular, oval, diamond, slits and the like.
  • perforated graphene-based materials include materials in which non-carbon atoms have been incorporated at the edges of the pores.
  • the two-dimensional material comprises graphene, molybdenum disulfide, or hexagonal boron nitride.
  • the two- dimensional material can be graphene.
  • Graphene can includes single-layer graphene, multi-layer graphene, or any combination thereof.
  • Other nanomaterials having an extended two-dimensional molecular structure can also constitute the two-dimensional material in the some embodiments.
  • molybdenum disulfide is a representative chalcogenide having a two-dimensional molecular structure, and other various chalcogenides can constitute the two-dimensional material in some embodiments.
  • Choice of a suitable two-dimensional material for a particular application can be determined by a number of factors, including the chemical and physical environment into which the graphene or other two-dimensional material is to be terminally deployed.
  • materials employed in making an enclosure are biocompatible or can be made biocompatible.
  • combinations of two-dimensional materials may be used in a multilayer or multi-sheet configuration to make an enclosure. For example, a first two- dimensional material in the multilayer or multi-sheet configuration, nearer an interior of an enclosure, could provide structural support while a second two-dimensional material of the multilayer or multi-sheet configuration, nearer the external environment, could impart biocompatibility.
  • perforation The process of forming holes in graphene and other two-dimensional materials will be referred to herein as “perforation,” and such nanomaterials will be referred to herein as being “perforated.”
  • a graphene sheet an interstitial aperture is formed by each six carbon atom ring structure in the sheet and this interstitial aperture is less than one nanometer across.
  • this interstitial aperture is believed to be about 0.3 nanometers across its longest dimension (the center to center distance between carbon atoms being about 0.28 nm and the aperture being somewhat smaller than this distance).
  • Perforation of sheets comprising two-dimensional network structures typically refers to formation of holes larger than the interstitial apertures in the network structure.
  • holes can be created using focused ion beam drilling, ion bombardment, nanoparticle bombardment, and combinations thereof.
  • lithographic techniques can be used to remove matter from the planar structure of two- dimensional materials to create holes.
  • the holes produced in the graphene or other two-dimensional material can range from about 0.3 nm to about 50 nm in size. In some embodiments, hole sizes can range from 1 nm to 50 nm. In some embodiments, hole sizes can range from 1 nm to 10 nm. In some embodiments, hole sizes can range from 5 nm to 10 nm. In some embodiments, hole sizes can range from 1 nm to 5 nm. In some embodiments, the holes can range from about 0.5 nm to about 2.5 nm in size. In some embodiments, the hole size is from 0.3 to 0.5 nm. In some embodiments, the hole size is from 0.5 to 10 nm.
  • the hole size is from 5 nm to 20 nm. In some embodiments, the hole size is from 0.7 nm to 1.2 nm. In some embodiments, the hole size is from 10 nm to 50 nm. In some embodiments where larger hole sizes are preferred, the hole size is from 50 nm to 100 nm, from 50 nm to 150 nm, or from 100 nm to 200 nm.
  • substance is used genetically herein to refer to atoms, ions, molecules, macromolecules, viruses, cells, particles and aggregates thereof.
  • Substances of particular interest are molecules of various size, including biological molecules, such as DNA, RNA, proteins and nucleic acids.
  • Substances can include pharmaceuticals, drugs, medicaments and therapeutics, which include biologies and small molecule drugs.
  • Figure 25 shows an illustrative schematic demonstrating the thickness of graphene in comparison to conventional drug delivery vehicles and devices.
  • the biocompatibility of graphene can further promote this application, particularly by functionalizing the graphene to be compatible with a particular biological environment (e.g., via available edge bonds, bulk surface functionalization, pi-bonding, and the like). Functionalization can provide membranes having added complexity for use in treating local and systemic disease.
  • Figure 25 illustrates a wall of an enclosure formed with perforated two-dimensional material having hole sizes in the range of 400-700 nm which will retain active cells.
  • the external biological environment abutting the enclosure (the full enclosure is not shown) is illustrated with an optional porous substrate layer adjacent and external to the perforated two-dimensional material and an optional woven support material external to the perforated two-dimensional material.
  • implantation of such an enclosure contemplates vascularization into any such substrate layer materials.
  • hole sizes can be tailored to prevent entrance of antibodies into the enclosure.
  • sealed enclosures primarily formed from a two-dimensional material, such as graphene, that remain capable of bi-directional transportation of materials.
  • at least one section or panel of the enclosure contains appropriately sized perforations in the two-dimensional material to allow ingress and egress, respectively, of materials of a desired size to and from the interior of the enclosure.
  • the two-dimensional material such as graphene
  • a suitable porous substrate can include, for example, thin film polymers; ceramics and inorganic materials, such as Si 3 N 4 , SiO 2 , Si; thin metal films (e.g., Ti, Au); track-etched polyimide; polycarbonate; PET; and combinations thereof.
  • the enclosure comprises two or more two-dimensional material layers.
  • an intermediate layer is positioned between two separate two-dimensional layers.
  • the intermediate layer is porous.
  • the intermediate layer comprises carbon nanotubes, lacey carbon, nanoparticles, lithographically patterned low-dimensional materials, silicon and silicon nitride micromachined material, a fine mesh, such as a transmission electron microscopy grid, or combinations of these.
  • the intermediate layer is functionalized. In some embodiments, the intermediate layer is functionalized.
  • functionalization comprises surface charges (e.g., sulfonates) attached to or embedded in the intermediate layer.
  • surface charges e.g., sulfonates
  • surface charges can impact molecules and/or ions that can traverse the membrane.
  • functionalization comprises specific binding sites attached to or embedded in the intermediate layer.
  • functionalization comprises proteins or peptides attached to or embedded in the intermediate layer.
  • functionalization comprises antibodies and/or antigens (e.g., IgG-binding antigens) or an antibody-binding fragment thereof attached to or embedded in the intermediate layer.
  • functionalization comprises adsorptive substances attached to or embedded in the intermediate layer.
  • functionalization involves catalytic and/or regenerative substances or groups.
  • functionalization comprise a negatively or partially negatively charged group (e.g., oxygen) attached to or embedded in the intermediate layer.
  • functionalization comprises a positively or partially positively charged group attached to or embedded in the intermediate layer.
  • the functionalization moieties are free to diffuse within the intermediate layer.
  • the functionalization moieties are trapped between two two-dimensional material layers, but are not restricted to a single position in the channel (i.e., they are mobile within the intermediate layer, but are inhibited from traversing the two-dimensional material layers, e.g., based the size of the pores in the two-dimensional material layers).
  • functionalization of the intermediate layer functions as an entrainment layer, and inhibits substances from traversing the membrane that would be able to traverse the membrane absent the functionalization.
  • functionalization imparts a selective permeability upon the membrane based on properties of potential permeants such as charge, hydrophobicity, structure, etc.
  • a substrate layer is disposed on one or both surfaces of the graphene-based material layer. Without being bound by theory, it is believed that the substrate layer can improve biocompatibility of membranes, for instance by reducing biofouling;
  • the substrate layer can increase vascularization near the enclosure, thus prompting the formation of blood vessels and/or tissue ingrowth in close proximity to the enclosure.
  • the substrate is disposed directly on the graphene-based material layer. In some embodiments, the substrate is disposed indirectly on the graphene-based material layer; for instance, an intermediate layer can be positioned between the substrate layer and the graphene-based material layer. In some embodiments, the graphene-based material layer is suspended on a substrate layer. In some embodiments, the substrate layer is affixed to the graphene-based material layer.
  • the substrate layer can be porous and/or nonporous.
  • the substrate layer contains porous and nonporous sections.
  • the substrate layer comprises a porous or permeable fibrous layer.
  • Porous substrates include, for example, one or more of ceramics and thin film polymers. Exemplary ceramics include nanoporous silica (silicon dioxide), silicon, SiN, and combinations thereof.
  • the substrate layer comprises track-etched polymers, expanded polymers, patterned polymers, woven polymers, and/or non-woven polymers.
  • the substrate layer comprises a plurality of polymer filaments.
  • the polymer filaments can comprise a thermopolymer, thermoplastic or melt polymer, e.g., that can be molded or set in an optional annealing step.
  • the polymer filaments are hydrophobic. In some embodiments, the polymer filaments are hydrophilic.
  • the substrate layer comprises a polymer selected from the group consisting of polysulfones, polyurethane, polymethylmethacrylate (PMMA), polyglycolid acid (PGA), polylactic acid (PLA), polyethylene glycol (PEG), polylactic-co-glycolic acid (PLGA), polyamides (such as nylon-6,6, supramid and nylamid), polyimides, polypropylene, polyethersulfones (PES), polyvinylidine fluoride (PVDF), cellulose acetate, polyethylene, polypropylene, polycarbonate, polytetrafluoroethylene (PTFE) (such as Teflon), polyvinylchloride (PVC), polyether ether ketone (PEEK), mixtures and block co-polymers of any of these, and combinations and/or mixtures thereof.
  • the polymers are biocompatible, bioinert and/or medical grade materials.
  • the substrate layer comprises a biodegradable polymer.
  • a substrate layer forms a shell around the enclosure.
  • the substrate layer shell, or a portion thereof can be dissolved or degraded, e.g., in vitro.
  • Suitable techniques for depositing or forming a porous or permeable polymer on the graphene-based material layer include casting or depositing a polymer solution onto the graphene-based material layer or intermediate layer using a method such as spin-coating, curtain coating, doctor-blading, immersion coating, electrospinning, or other similar techniques.
  • Electrospinning technique are described, e.g., in US 2009/0020921 and/or U.S. Application No. 14/609,325, both of which are hereby incorporated by reference in their entirety.
  • the process for forming a substrate layer includes an electrospinning process in which a plurality of polymer filaments are laid down to form a porous mat, e.g., on the graphene-based material layer.
  • the mat has pores or voids located between deposited filaments of the fibrous layer.
  • Figure 25 shows an illustrative SEM micrograph of a graphene or graphene-based film deposited upon a plurality of electrospun PVDF fibers.
  • the electrospinning process comprises a melt
  • the polymer can be present in a spin dope at a concentration of 2 wt.% to 15 wt.%, or 5 wt.% to 10 wt.%, or about 7 wt.%.
  • Suitable solvents for the spin dope include any solvent that dissolves the polymer to be deposited and which rapidly evaporates, such as m-cresol, formic acid, dimethyl sulfoxide (DMSO), ethanol, acetone, dimethylacetamide (DMAC), dimethylformamide (DMF), water, and combinations thereof.
  • the spin dope solvent is biocompatible and/or bioinert.
  • the amount of solvent used can influence the morphology of the substrate layer.
  • the spun fibers of the fibrous layer can remain as essentially discrete entities once deposited.
  • wet electrospinning processes deposit the spun fibers such that they are at least partially fused together when deposited.
  • the size and morphology of the deposited fiber mat e.g., degree of porosity, effective pore size, thickness of fibrous layer, gradient porosity
  • the porosity of the fibrous layer can include effective porosity values— i.e., void space values— (e.g. measured via imagery or porometry methods) of up to about 95% (i.e., the layer is 95% open), about 90%, about 80%, or about 60% with a broad range of pore sizes.
  • effective porosity values i.e., void space values— (e.g. measured via imagery or porometry methods) of up to about 95% (i.e., the layer is 95% open), about 90%, about 80%, or about 60% with a broad range of pore sizes.
  • void space values e.g. measured via imagery or porometry methods
  • the spun fibers in an electrospun fibrous layer can have a fiber diameter ranging from about 1 nm to about 100 ⁇ m, or about 10 nm to about 1 ⁇ m, or about 10 nm to about 500 nm, or about 100 nm to about 200 nm, or about 50 nm to about 120 nm, or about 1 ⁇ to about 5 ⁇ m, or about 1 ⁇ to about 6 ⁇ m, or about 5 ⁇ to about 10 ⁇ .
  • the fiber diameter is directly correlated with a depth (Z-axis) of a pore abutting the graphene-based material layer (disposed in the X-Y plane), and large diameter fibers can lead to large unsupported spans of material.
  • the substrate layer can have pores with an effective pore size of from about 1 nm to about 100 ⁇ m, or about 10 nm to about 1 ⁇ m, or about 10 nm to about 500 nm, or about 100 nm to about 200 nm, or about 50 nm to about 120 nm, or about 1 ⁇ to about 5 ⁇ , or about 1 ⁇ to about 6 ⁇ , or about 5 ⁇ to about 10 ⁇ .
  • Pore diameters in the substrate layer can be measure, for example, via a bubble point method.
  • the substrate layer can have an average pore size gradient throughout its thickness.
  • Pore size gradient describes a layer with a plurality of pores, where the average diameter of the pores increases or decreases based on the proximity of the pore to the graphene-based material layer.
  • a fibrous layer can have an average pore size gradient that decreases nearer the surface of a graphene-based material.
  • an average pore size of the fibrous layer is smaller nearer the surface of the graphene-based material than at an opposite surface of the fibrous layer.
  • the fibrous layer can have effective pore diameters of from about 1 ⁇ to about 6 ⁇ close to the intermediate layer or the graphene-based material layer which can increase to greater than 100 ⁇ at the maximum distance away from the intermediate layer or graphene-based material layer.
  • the fibrous layer can have a "porosity gradient" throughout its thickness, which can be measured for instance using imagery.
  • “Porosity gradient,” as used herein, describes a change, along a dimension of the fibrous layer, in the porosity or total pore volume as a function of distance from the graphene-based material layer.
  • the porosity can change in a regular or irregular manner.
  • a porosity gradient can decrease from one face of the fibrous layer to the other.
  • the lowest porosity in the fibrous layer can be located spatially closest to the graphene-based material layer, and the highest porosity can be located farther away (e.g., spatially closer to an external environment).
  • a porosity gradient of this type can be achieved by electrospinning fibers onto a graphene-based material layer such that a fiber mat is denser near the surface of the graphene-based material layer and less dense further from the surface of the graphene-based material layer.
  • a substrate layer can have a relatively low porosity close to the graphene-based material layer, a higher porosity at a mid-point of the fibrous layer thickness (which can, for example, contain a supporting mesh for reinforcement or other particles), and return to a relatively low porosity at an external surface distal to the graphene-based material layer.
  • the substrate layer can have a "permeability gradient" throughout its thickness.
  • Permeability gradient describes a change, along a dimension of the fibrous layer, in the "permeability” or rate of flow of a liquid or gas through a porous material. For example, throughout the thickness of the fibrous layer, the permeability can change in a regular or irregular manner. A permeability gradient can decrease from one face of the fibrous layer to the other. For example, the lowest permeability in the fibrous layer can be located spatially closest to the graphene-based material layer, and the highest permeability can be located farther away. Those of skill in the art will understand that permeability of a layer can increase or decrease without pore diameter or porosity changing, e.g., in response to chemical functionalization, applied pressure, voltage, or other factors.
  • the enclosure can be supported by one or more support structures.
  • the support structure can itself have a porous structure wherein the pores are larger than those of the graphene-based material layer.
  • the support structure is entirely porous (i.e., the support structure is formed as a frame at a perimeter of a graphene-based material layer).
  • the support structure is at least in part non-porous comprising some structure interior to a perimeter of a graphene-based material layer.
  • the thickness and structure of the substrate layer can be chosen to convey a desired degree of structural support (e.g., to prevent tearing and/or buckling) to the graphene-based material layer.
  • the substrate layer can have a thickness of about 1 mm or less, or about 1 ⁇ m or less.
  • a thickness of the substrate layer can range from about 100 nm to about 100 ⁇ m, or about 1 ⁇ m to about 50 ⁇ m, or about 10 ⁇ to about 20 ⁇ m, or about 15 ⁇ to about 25 ⁇ m.
  • the substrate layer has a thickness greater than about 5 ⁇ m, or greater than about 10 ⁇ m, or greater than about 15 ⁇ m.
  • the substrate layer has a thickness of less than 1 ⁇ m.
  • both the graphene-based material layer and the substrate layer include a plurality of pores therein.
  • both the graphene-based material layer and the substrate layer contain pores, and the pores in the graphene-based material layer are smaller, on average, than the pores in the substrate layer.
  • the median pore size in the graphene-based material layer are smaller than the median pore size in the substrate layer.
  • the substrate layer can contain pores with an average and/or median diameter of about 1 ⁇ or larger and the graphene-based material layer can contain pores with an average and/or median diameter of about 10 nm or smaller.
  • the average and/or median diameter of pores in the graphene-based material layer are at least about 10-fold smaller than are the average and/or median diameter of pores in the substrate layer. In some embodiments, the average and/or median diameter of pores in the graphene-based material layer are at least about 100-fold smaller than are the average and/or media diameter of pores in the substrate layer.
  • the substrate layer can provide a scaffold for tissue growth, cell growth, support, and/or vascularization.
  • the substrate layer or wall comprises additives, such as pharmaceuticals, cells, growth factors (e.g., VEGF), signaling molecules, cytokines, clotting factors, blood thinners, immunosuppressants, antimicrobial agents, hormones, antibodies, minerals, nutrients or combinations thereof.
  • additives such as pharmaceuticals, cells, growth factors, clotting factors, blood thinners, immunosuppressants, antimicrobial agents, hormones, antibodies, antigens (e.g., IgG-binding antigens) or an antibody-binding fragment thereof, minerals, nutrients or combinations thereof are positioned on the inside of the disclosure.
  • the substrate layer or wall comprises materials toxic to bacteria or cells (without being bound by theory, it is believed that incorporating toxic materials into the wall will prevent passage of potentially dangerous cells across the wall).
  • additives beneficially promote cell or tissue viability or growth, reduce or prevent infection, improve vascularization to or near the enclosure, improve biocompatibility, reduce biofouling, and/or reduce the risk of adverse reactions.
  • additives can modulate properties, such as hydrophobicity or hydrophilicity, of the substrate layer.
  • additives can be used to modulate elution of a substance from a compartment in the enclosure. For instance, additives can confer shell-like properties to a substrate layer, such that degradation or removal of the additives allows substances in the compartment to escape the enclosure (and, by extension, substances from the external environment to enter to enclosure).
  • the enclosures have a single compartment without sub- compartments.
  • the enclosures can have a plurality of sub-compartments within the main enclosure each sub-compartment comprises perforated two-dimensional material to allow passage of one or more substance into or out of the sub-compartment.
  • sub-compartment can have any useful shape or size.
  • 2 or 3 sub-compartments are present.
  • the main enclosure B completely contains a smaller enclosure A, such that substances in the centermost enclosure A can pass into the main enclosure B, and potentially react with or within the main compartment during ingress and egress therefrom.
  • one or more substance in A can pass into B and one or more substance in A can be retained in A and not to B.
  • Two sub compartments in which one or more substance can pass directly between the sub-compartments are in direct fluid communication. Passage between sub-compartments and between the enclosure and the external environment is via passage through the holes of a perforated two-dimensional material.
  • the barrier membrane, i.e.
  • perforated two-dimensional material between compartment A and B can be permeable to all substances in A or selectively permeable to certain substances in A.
  • the barrier (membrane) between B and the external environment can be permeable to all substances in B or selectively permeable to certain substances in B.
  • sub-compartment A is in direct fluid communication with sub-compartment B which in turn is in direct fluid
  • Compartment A in this nested configuration is only in indirect fluid communication with the external environment via intermediate passage into sub-compartment B.
  • the two-dimensional materials employed in different sub-compartments of a given enclosure may be the same or different materials and the perforations or hole sizes in the two-dimensional material of different sub-compartments may be the same or different dependent upon the substances involved and the application.
  • the enclosure is bisected with an impermeable wall (e.g., formed of non-porous or non-permeable sealant) forming sub-compartments A and B, such that both sections have access to the egress location independently, but there is no direct or indirect passage of substances from A to B. (It will be appreciated, however, that substances exiting A or B may enter the other sub-compartment indirectly via the external environment.)
  • an impermeable wall e.g., formed of non-porous or non-permeable sealant
  • embodiments also can interact with one another, i.e. the sub-compartments are in direct fluid communication.
  • the barrier (membrane) between compartments A and B is selectively permeable, for example allowing at least one substance in A to pass into B, but not allowing the substances originating in B to pass to A.
  • Figure 26D illustrates an enclosure having three compartments.
  • the enclosure is illustrated with sub-compartment A having egress into sub-compartment B, which in turn has egress into sub -compartment C, which in turn has egress to the external environment.
  • Compartments A and B have no egress to the external environment, i.e. they are not in direct fluid communication with the external environment.
  • Adjacent sub-compartments A and B and adjacent sub-compartments B and C are each separated by a perforated two-dimensional material and are thus in direct fluid communication with each other.
  • Sub-compartment A is only in indirect fluid communication with compartment C and the external environment via sub- compartment B or B and C, respectively.
  • Various other combinations of semi-permeable barrier (membranes) or non-permeable barriers can be employed to separate compartments in the enclosures.
  • Various perforation size constraints can change depending on how the enclosure is ultimately configured (e.g., if one enclosure is within another versus side-by-side).
  • the boundaries or at least a portion thereof, of the enclosure can be constructed from a two-dimensional material in order to realize the benefits thereof, specifically such that the thickness of the active membrane is less than the diameter of the target to be passed selectively across the membrane.
  • the pore size of the two-dimensional material can range between about 0.3 nm to about 10 nm in size. Larger pore sizes are also possible.
  • Figure 26E illustrates an enclosure having multiple compartments in a radial array around a central compartment. In the embodiment shown, central compartment E is surrounded by four compartments A-D. Top and bottom surfaces of compartment E may also be joined to compartments that are not shown.
  • the central compartment of a radial array may have a hexagonal, octahedral, decahedral, dodecahedral or circular shape to increase the number of connection points for the radially arranged compartments.
  • compartment E has egress into compartments A-D, which in turn have egress to the external environment.
  • Compartment E does not have egress to the external environment, i.e. it is not in direct fluid communication with the external environment.
  • Compartments A-D have egress to the external environment through at least one section of permeable two-dimensional membrane, but in some embodiments compartments A-D may be formed entirely by a permeable two-dimensional membrane.
  • Figure 26F illustrates an enclosure having a single compartment (A) and no sub- compartments.
  • the compartment is in direct fluid communication with an environment external to the enclosure.
  • compartment E may independently transfer molecules to, receive molecules from, or exchange molecules with compartments A, B, C and/or D.
  • compartment E may contain a biological organism producing a molecule that is transferred to one or more of compartments A-D, which may contain different molecules capable of reacting with the molecule produced in the central compartment.
  • central compartment E may receive one or more molecules from one or more of the radial compartments A-D, such that compartment E acts as a reaction chamber. In such an embodiment, it may be useful for compartments A-D to only have egress to an external environment through central compartment E.
  • the perforated two-dimensional material separating the central compartment from each of the radially arranged compartments may be the same or different in terms of composition and hole size.
  • the sub-compartments are connected by microfluidic channels.
  • the microfluidic channels comprise valves.
  • substances can diffuse between sub-compartments.
  • substances can pass between sub-compartments via a tortuous path membrane.
  • reaction rates between substances in two sub-compartments can be controlled by modulating the ability of the substances to pass from the first sub-compartment to the second sub-compartment, and vice versa.
  • Some embodiments comprise a device comprising more than one enclosure (such as 2, 3, 4, 5, 6, 7, 8, 9, 10, or more than 10 enclosures), where at least a portion of the enclosures are connected such that a reservoir is formed between the enclosures.
  • at least a portion of the enclosures are connected by microfluidic channels.
  • the microfluidic channels comprise valves.
  • substances can diffuse between at least a portion of the enclosures.
  • substances can pass between at least a portion of the enclosures via a tortuous path membrane.
  • reaction rates between substances in different enclosures can be controlled by modulating the ability of the substances to pass from one enclosure to the other enclosure, and vice versa.
  • Some embodiments comprise two or more enclosures configured in a similar manner to the sub-compartments described above. For instance, two enclosures can be positioned in a nested configuration, where only the outer enclosure is in fluid communication with an environment external to the enclosure. In some embodiments with a nested enclosure
  • the outermost enclosure comprises a substance that is released over a period of days, weeks, months, or years.
  • the innermost enclosure comprises a substance that is released after the substance in the outermost enclosure is substantially depleted, at which point the substance from the innermost enclosure can pass through the outermost enclosure and into the external environment.
  • a polymer protective shell e.g., a polymer coating surrounding the inner enclosure is degraded after a certain time period, for instance after the substance in the outermost enclosure is depleted.
  • devices with more than two nested enclosures can be used. Without being bound by theory, it is believed that a nested enclosure configuration can be used for sustained substance release and/or weaning a subject off a pharmaceutical product.
  • Some embodiments comprise a means for moving substances and/or fluid between sub-compartments. Some embodiments comprise a means for moving substances and/or fluid between enclosures and/or reservoirs positioned between the enclosures. For instance, passage of substances and/or fluids can be in response to a concentration gradient, electric potential, or pressure difference. In some embodiments, passage of substances and/or fluids can be in response to activating or deactivating electrically gated pores.
  • passage of substances and/or fluid is via osmosis.
  • an osmotic engine is used to influence passage of substances and/or fluids.
  • osmosis is triggered based on a change in basal cell chemistry. For instance, the presence of antibodies or an immune-mediated response can trigger the release of substances from the enclosure (for example, an immune response could trigger release of antibiotics from the enclosure device).
  • a piston is used to influence passage of substances and/or fluids (e.g., the piston can be used to push out or draw in substances/fluids from an enclosure and/or reservoir).
  • passage of substances and/or fluid between enclosures and/or reservoirs is via an automated or triggered release of the substances and/or fluid.
  • the passage is triggered by a microchip positioned in or on the device.
  • the microchip is triggered by a triggering device located external to the enclosure device.
  • the enclosure can be supported by one or more support structures.
  • the support structure can itself have a porous structure wherein the pores are larger than those of the two-dimensional material.
  • the support structure is entirely porous.
  • the support structure is at least in part non-porous.
  • the multiple physical embodiments for the enclosures and their uses can allow for various levels of interaction and scaled complexity of problems to be solved.
  • a single enclosure can provide drug elution for a given time period, or there can be multiple sizes of perforations to restrict or allow movement of distinct targets, each having a particular size.
  • added complexity with multiple sub-compartments can allow for interaction between target compounds to catalyze or activate a secondary response (i.e., a "sense-response" paradigm).
  • a secondary response i.e., a "sense-response" paradigm.
  • exemplary compound A may undergo a constant diffusion into the body, or either after time or only in the presence of a stimulus from the body.
  • exemplary compound A can activate exemplary compound B, or inactivate functionalization blocking exemplary compound B from escaping.
  • the bindings to produce the foregoing effects can be reversible or irreversible.
  • exemplary compound A can interact with chemical cascades produced outside the enclosure, and a metabolite subsequent to the interaction can release exemplary compound B (by inactivating
  • growth factors and/or hormones can be loaded in the enclosure to encourage vascularization (see Figure 25).
  • cell survival can be far superior as a result of bi-directional transport of nutrients and waste.
  • the relative thinness of graphene can enable bi-directional transport across the membrane enclosure in close proximity to blood vessels, particularly capillary blood vessels, and other target cells.
  • using a graphene-based enclosure can provide differentiation over other solutions accomplishing the same effect because the graphene membrane is not appreciably limiting the permeability.
  • the diffusion of molecules through the medium or interstitial connections can limit the movement of a target.
  • a "sense-response" paradigm with graphene is enabled by a superior time response.
  • the biocompatibility of graphene can further enhance this application.
  • graphene is less susceptible to biofouling and clogging than traditional permeable materials and adsorbed species may be removed by electrification of graphene.
  • Expansion to functionalized graphene membranes for added complexity in treating local and systemic disease is also predicted to lower the degree of biofouling, due to electrostatic repulsion by the functional moieties.
  • the mechanical stability of graphene can make it suitable to withstand physical stresses and osmotic stresses within the body.
  • Figures 27A and 27B provide a schematic illustration of enclosures with a single compartment for immunoisolation (it will be appreciated that the enclosure can having a plurality of sub-compartments, for example, two or three sub-compartments).
  • the enclosure (2730) of Figure 27 A is shown as a cross-section formed by an inner sheet or layer (2731) comprising perforated two-dimensional material, such as a graphene-based material, and an outer sheet or layer (2732) of a substrate material (though in some embodiments, the inner layer comprises the substrate material, and the outer layer comprises the perforate two-dimensional material).
  • the substrate material can be porous, selectively permeable or non-porous, and/or and non- permeable.
  • Figure 27 provides an alternative cross-section of the enclosure of Figure 27 A, showing the space or cavity formed between a first composite layer (2732/2731) and a second composite layer (2732/2731) (in the figure, the cavity is depicted to contain roughly circular symbols, which can be cells or any other substance) where a sealant 2734 is illustrated as sealing the edges of the composite layers.
  • seals at the edges of the composite layers can be formed employing physical methods, such as clamping, crimping, or with adhesives. Methods and materials for forming the seals at the edges are not particularly limiting.
  • the sealing material provides a non-porous and non-permeable seal or closure.
  • a portion of the enclosure is formed from a sealant, such as a silicone, epoxy, polyurethane or similar material.
  • the sealant is biocompatible. For instance, in some
  • the seal does not span the entire length or width of the device. In some embodiments the seal does not span the entire length or width of the device.
  • the seal forms a complete loop around the cavity.
  • the seal is formed as a frame at a perimeter of a two-dimensional material.
  • the seal is positioned, at least in in part, interior to a perimeter of a two-dimensional material.
  • the enclosure is permeable to desirable products, such as growth factors produced by the cells.
  • the cells within the enclosure are immune- isolated.
  • hole sizes in perforated two-dimensional materials useful for immunoisolation range in size from about 1-20 nm, about 1-10 nm, about 3-10 nm, or about 3-5 nm.
  • the holes are from about 1 nm to about 30 nm in size, such as about 30 nm, about 20 nm, about 18 nm, about 15 nm, about 10 nm, about 5 nm, or about 3 nm. See, e.g., Song et al., Scientific Reports, 6: 23679, doi: 10.1038/srep23679 (2016), which is incorporated herein by reference in its entirety.
  • Figures 28A-28C illustrate an exemplary method for forming an enclosure and introducing selected substances, for example cells therein. The method is illustrated with use of a sealant for forming the enclosure.
  • the exemplary enclosure has no sub-compartment.
  • a first composite layer or sheet is formed by placing a sheet or layer of two-dimensional material, particularly a sheet of graphene-based material or a sheet of graphene (2841), in contact with a support layer (2842). At least a portion of the support layer (2842) of the first composite is porous or permeable. Pore size of the support layer is generally larger than the holes or apertures in the two-dimensional material employed and may be tuned for the environment (e.g. body cavity).
  • silicone is applied on the sheet or layer of perforated two-dimensional material outlining a compartment of the enclosure wherein the sealant will form a non-permeable seal around a perimeter of the enclosure. Formation of a single compartment is illustrate in Figures 28A-28C, however, it will be appreciated that multiple independent compartments within an enclosure can be formed by an analogous process.
  • a second composite layer formed in the same way as the first can be prepared and positioned with the sheet or layer of perforated two dimensional materials in contact with the sealant. (Alternatively, a sealant can be applied to a portion of composite layer and the layer can be folded over in contact with the sealant to form an enclosure. A seal is then formed between the two composite layers.
  • an alternative enclosure can be formed by applying a sheet or layer of non-porous and non-permeable support material in contact with the sealant. In this case only a portion of the enclosure is porous and permeable. Sealed composite layers are illustrated in Figure 284B where it is shown that the sealed layers can be trimmed to size around the sealant to form the enclosure.)
  • the enclosure formed is shown to have an external porous support layer 2842, the sheet or layer of perforated two-dimensional material (2841) being positioned as an internal layer, with sealant 2844 around the perimeter of the enclosure.
  • cells or other substances that would be excluded from passage through the perforated to-dimensional sheet or layer can be introduced into the enclosure after it formed by injection through the sealant layer. Any perforation formed by such injection can be sealed as needed. It will be appreciated that substances and cells can be introduced into the enclosure prior to formation of the seal. Those in the art will appreciate that sterilization methods appropriate for the application envisioned may be employed during or after the preparation of the enclosure.
  • an enclosure comprises perforated two-dimensional material encapsulating a substance, such that the substance is released to an environment external to the enclosure by passage through the holes in the perforated two-dimensional material.
  • the enclosure encapsulates more than one different substance.
  • not all of the different substances are released to an environment external to the enclosure. In some embodiments, all of the different substances are released into an environment external to the enclosure. In some embodiments, different substances are released into an environment external to the enclosure at different rates. In some embodiments, different substances are released into an environment external to the enclosure at the same rates.
  • the enclosure comprises two or more sub-compartments, wherein at least one sub-compartment is in direct fluid communication with an environment external to the enclosure through holes in a two-dimensional material of the sub-compartment.
  • each sub-compartment comprises a perforated two-dimensional material and each sub-compartment is in direct fluid communication with an environment external to the enclosure, through holes in the two-dimensional material of each sub-compartment.
  • an enclosure is subdivided into two sub-compartments separated from each other at least in part by perforated two-dimensional material, such that the two-sub-compartments are in direct fluid communication with each other through holes in two- dimensional material.
  • the enclosure is subdivided into two-sub- compartments each comprising two-dimensional material which sub-compartments are in direct fluid communication with each other through holes in two-dimensional material and only one of the sub-compartments is in direct fluid communication with an environment external to the enclosure.
  • the enclosure is subdivided into two-sub-compartments each comprising two-dimensional material which sub-compartments are in direct fluid communication with each other through holes in two-dimensional material and both of the sub-compartments are also in direct fluid communication with an environment external to the enclosure.
  • the enclosure has an inner sub-compartment and an outer sub- compartment each comprising a perforated two-dimensional material, wherein the inner sub- compartment is entirely enclosed within the outer sub-compartment, the inner and outer compartments are in direct fluid communication with each other through holes in two- dimensional material and the inner sub-compartment is not in direct fluid communication with an environment external to the enclosure.
  • an enclosure has a plurality of sub-compartments each comprising a two-dimensional material
  • the sub-compartments are nested one within the other, each of which sub-compartments is in direct fluid communication through holes in two- dimensional material with the sub-compartment(s) to which it is adjacent, the outermost sub- compartment in direct fluid communication with an environment external to the enclosure, the remaining plurality of sub-compartments not in direct fluid communication with an environment external to the enclosure.
  • each sub-compartment is in direct fluid communication with one or more adjacent sub-compartments, and only one sub- compartment is in direct fluid communication with an environment external to the enclosure.
  • the enclosure comprises two sub-compartments, where (i) the first sub-compartment is in fluid communication with an environment external to the enclosure and comprises a substance such as a pharmaceutical, a drug, a medicament, a therapeutic, a biologic, a small molecule, and combinations thereof and (ii) the second compartment comprises a semi-permeable membrane not abutting the first sub-compartment.
  • osmosis occurs across the semi-permeable membrane in the second sub-compartment, thereby increasing pressure on the first sub-compartment (e.g., using a piston-like driving force). In some embodiments, this increased pressure increases the diffusion rate of the substance in the first sub-compartment into the environment external to the enclosure.
  • the at least one substance within the enclosure that is released to an environment external to the enclosure through holes in two-dimensional material is a pharmaceutical, therapeutic or drug.
  • the two-dimensional material of the enclosure for release of the substance comprises holes ranging in size from 1-50 nm.
  • the two-dimensional material of the enclosure for release of the substance comprises holes ranging in size from 1-10 nm.
  • the substance within the enclosure is cells and the size of the holes in the two-dimensional material is selected to retain the cells within the enclosure and to exclude immune cells and antibodies from entering the enclosure from an environment external to the enclosure.
  • the enclosure is divided into a plurality of sub-compartments and one or more sub-compartments contain cells.
  • An enclosure can contain different cells with a sub-compartment or different cells within different sub- compartments of the same enclosure.
  • the enclosure is a nested enclosure wherein the cells are within the inner sub-compartment.
  • an enclosure has an inner sub-compartment and an outer sub- compartment each comprising a perforated two-dimensional material wherein the inner sub- compartment is entirely enclosed within the outer sub-compartment, the inner and outer compartments are in direct fluid communication through holes in two-dimensional material of the inner sub-compartment, the inner sub-compartment is not in direct fluid communication with an environment external to the enclosure and the outer compartment is in direct fluid communication with an environment external to the enclosure.
  • an enclosure has a plurality of sub- compartments each of which comprises perforated two-dimensional material and each of which sub -compartments is in direct fluid communication with one or more adjacent sub- compartments, the cells being within one or more cell-containing sub-compartments each of which are not in direct fluid communication with an environment external to the enclosure.
  • the cells are yeast cells or bacterial cells. In some embodiments of enclosures containing cells, the cells are mammalian cells. In some embodiments of enclosures containing cells, the size of the holes, in the two- dimensional material of the enclosure or sub-compartment, ranges from 1-10 nm, 3-10 nm, or from 3-5 nm.
  • two-dimensional material in the enclosure is supported on a porous substrate.
  • the porous substrate can be polymer or ceramic.
  • the two-dimensional material is a graphene-based material. In some embodiments, the two-dimensional material is graphene.
  • the holes, or a portion thereof, in the two- dimensional materials of the enclosure are functionalized.
  • the external surface of the enclosure is functionalized.
  • functionalization comprises surface charges (e.g., sulfonates) attached to the pores and/or surface of the enclosure. Without being bound by theory, it is believed that surface charges can impact molecules and/or ions that can traverse the membrane.
  • functionalization comprises specific binding sites attached to the pores and/or the surface of the enclosure.
  • functionalization comprises proteins or peptides attached to the pores and/or the surface of the enclosure.
  • functionalization comprises adsorptive substances attached to the pores and/or the surface of the enclosure.
  • functionalization involves catalytic and/or regenerative substances or groups.
  • functionalization comprise a negatively or partially negatively charged group (e.g., oxygen) attached to the pores and/or the surface of the enclosure.
  • functionalization comprises a positively or partially positively charged group attached to the pores and/or the surface of the enclosure.
  • functionalizing the pores and/or the surface of the enclosure functions: to restrict contaminants from traversing the membrane; to act as a disposable filter, capture, or diagnostic tool; increase biocompatibility (e.g., when polyethylene glycol is used for functionalization); increase filtration efficiency; and/or to increase selectivity at or near the pores or in asymmetric membranes.
  • At least a portion of the two-dimensional material is conductive and a voltage can be applied to at least a portion of the conductive two-dimensional material.
  • the voltage can be an AC or DC voltage.
  • the voltage can be applied from a source external to the enclosure.
  • a device comprising a two-dimensional material (such as an enclosure device) further comprises connectors and leads for application of a voltage from an external source to the two-dimensional material.
  • Some embodiments comprise methods of employing an enclosure in a selected environment for delivery of one or more substance to the environment.
  • the environment is a biological environment.
  • the enclosure is implanted into biological tissue.
  • the enclosure device is positioned such that the device or enclosure is positioned partially inside a subject's body and partially outside a subject's body (e.g., an enclosure can be used as a port or wound covering to allow drugs or biologies to be introduced without cells or other contaminants entering the body).
  • the enclosure is injected (e.g., through a needle).
  • the enclosure is ingested.
  • the enclosure is employed for delivery of a pharmaceutical, a drug or a therapeutic.
  • a method comprises introducing an enclosure comprising perforated two-dimensional material into a an environment, the enclosure containing at least one substance; and releasing at least a portion of at least one substance through the holes of the two- dimensional material to the environment external to the enclosure.
  • the enclosure contains cells which are not released from the enclosure and the at least one substance a portion of which is released is a substance generated by the cells in the enclosure.
  • a method comprises introducing an enclosure comprising perforated two-dimensional material to an environment, the enclosure containing at least one first substance; and receiving a second substance from the environment into the enclosure.
  • the first substance is cells
  • a second substance is nutrients and another second substance is oxygen.
  • the support layer can be a polymer or a ceramic material.
  • Useful exemplary ceramics include nanoporous silica, silicon or silicon nitride.
  • Useful porous polymer supports include solution-diffusion membranes, track-etched polymers, expanded polymers or non-woven polymers.
  • the support material can be porous or permeable.
  • a portion, e.g., a wall, side or portion thereof, of an enclosure or a sub-compartment can be non-porous polymer or ceramic.
  • Biocompatible polymers and ceramics are preferred.
  • a portion of the enclosure can be formed from a sealant, such as a silicone, epoxy, polyurethane or similar material. Biocompatible sealants are preferred.
  • a non-perforated wall or portion thereof of an enclosure is a metallic, polymeric or ceramic material. Biocompatible metals, polymers and ceramics are preferred, such as medical grade materials.
  • a non-perforated wall of an enclosure may be treated, e.g., on a surface interfacing with an external environment, to provide or improve biocompatibility.
  • the conductive properties of graphene-based or other two-dimensional membranes can allow for electrification to take place from an external source.
  • an AC or DC voltage can be applied to conductive two-dimensional materials (e.g., in a device such as an enclosure device).
  • the conductivity properties of graphene can provide additional gating to charged molecules or substances. Electrification can occur permanently or only a portion of the time to affect gating.
  • Directional gating of charged molecules can be directed not only through the pores (or restrict travel through pores), but also to the surface of the graphene to adsorb or bind and encourage growth, promote formation of a protective layer, or provide the basis or mechanism for other biochemical effects (e.g., on the body).
  • the membranes allow for electrostatic control of charged species, for instance in nanofluidic or microfluidic systems. In some embodiments, the membranes allow for control of charged species by varying the applied voltage, for instance in nanofluidic or microfluidic systems. In some embodiments, the membrane can be tuned to manipulate ion transport at low and/or high ion concentrations. In some embodiments, the membrane is an ion-selective membrane. In some embodiments, the membrane comprises one or more voltage-gated ion channels, such as voltage-gated pores. In some embodiments, the membranes mimic biological voltage-gated ion channels.
  • the gated graphene functions as an artificial membrane, e.g., when used in an artificial organ or organelle.
  • the membrane is a solid-state membrane.
  • nanochannel or nanopore transistors can be used to manipulate ion transport.
  • the membrane can be tuned using low or high applied voltages. In some embodiments, the membrane allows high ionic flux. In some embodiments, the membrane allows low ion flux. In some embodiments, pores in the membrane modulate current of ions at low gate voltages and/or display high selectivity. In some embodiments, ion flux across the membrane can be turned on or off at low applied voltages, such as ⁇ 500 mV. In some embodiments, ion flux across the membrane can be turned on or off at biologically relevant ion concentrations, such as up to 1 M. In some embodiments, the applied voltage can modulate on species selectivity, e.g., cation or anion selectivity.
  • species selectivity e.g., cation or anion selectivity.
  • nanopores can be electrostatically controlled at low voltages and biologically relevant ion concentrations.
  • membranes are used in separation and sensing technologies.
  • membranes are used in water filtration, energy storage, microfluidic devices, nanofluidic devices, and/or therapeutic methods.
  • methods for separating ions or other substances relate to methods for sensing ions; methods for storing energy; methods for filtering water; and/or methods of treating a disease or condition.
  • Some embodiments relate to methods of nanofiltration and/or microfiltration. Some embodiments comprise using gating to control release of substances. Some embodiments comprise using gating to allow for different substances to be release at different times. Some embodiments comprise allowing different substances to pass through the membrane at different times, thus modulating when and how substances mix and interact with other substances in a specific order.
  • Some embodiments comprise enclosures where graphene allows implementation of a sense-response system.
  • graphene can be used to sense a variety of biomolecules, such as insulin.
  • the biomolecules are "sensed" based on an interaction between compounds with the graphene or with functional groups attached to the graphene.
  • the sense-response paradigm provides a feedback mechanism for monitoring the state of encapsulated materials.
  • Some embodiments comprise bioartificial liver configurations comprising an enclosure.
  • hepatocytes or liver cells can be encapsulated by the enclosure.
  • enclosures comprising encapsulated hepatocytes is implanted into a subject in need thereof, such as a subject with impaired liver function.
  • enclosures comprising encapsulated hepatocytes are used in an extracorporeal medical procedure.
  • the enclosure is loadable or reloadable, such that a metabolite can be injected into the enclosure to elicit a reaction, or the number or type of cells inside the enclosure can be modified (e.g., the cells inside the enclosure can be replaced).
  • Some embodiments comprise artificial kidney configurations comprising an enclosure.
  • kidney cells can be encapsulated by the enclosure.
  • enclosures comprising encapsulated kidney cells can be implanted into a subject in need thereof.
  • the enclosure is loadable or reloadable, such that a metabolite can be injected into the enclosure to elicit a reaction, or the number or type of cells inside the enclosure can be modified (e.g., the cells inside the enclosure can be replaced).
  • Some embodiments comprise artificial lungs comprising an enclosure.
  • the compartment in the enclosure is in gaseous communication with an environment external to the compartment.
  • some embodiments can be utilized in other areas as well. Some embodiments can be used in non-therapeutic applications such as, for example, the dosage of probiotics in dairy products (as opposed to the presently used microencapsulation techniques to increase viability during processing for delivery to the GI tract).
  • the enclosures and devices formed therefrom can span several orders of magnitude in size, depending on manufacturing techniques and various end use requirements. Nevertheless, the enclosures are believed to be able to be made small enough to circulate through the bloodstream. On the opposite end of the spectrum, the enclosures can be made large enough to implant (on the order of a few inches or greater). These properties can result from the two-dimensional characteristics of the graphene and its growth over large surface areas.
  • Graphene based materials and other two-dimensional materials may have undesirable defects present therein.
  • Defects are undesired openings formed in the graphene material. The presence of defects may render the graphene material unsuitable for filtration-type applications, as the defects may allow undesired molecules to pass through the material. In such applications, the presence of defects above a cutoff size or outside of a selected size range can be undesirable. On the other hand, defects below a critical size required for application-specific separation may be useful from a permeability perspective, as long as such defects do not negatively impact the integrity of the graphene. In some embodiments, defects may include holes, tears, slits, or any other shape or structure. Defects may be the result of manufacturing or handling the graphene material.
  • a process for repairing or mitigating the presence of defects in the graphene materials increases the utility of the materials as filtration or permeable membranes.
  • the repair process may selectively produce a polymer material within the defects of the graphene material, preventing flow through the defects.
  • the repair process may produce a graphene material 2900 with polymer regions 2910 that have filled defects in the graphene material, as shown in FIGS. 29 and 30.
  • the polymer regions 2910 are thin and may be a single layer of polymer molecules. As shown in FIG. 30, while the polymer regions 2910 are thin, they are thicker than the graphene material 2900.
  • a single layer of graphene may have a thickness of about 3.5 angstroms, while a polymer region including a single layer of polymer molecules may have a thickness of a few nanometers or more, depending on the polymer.
  • Graphene represents a form of carbon in which the carbon atoms reside within a single atomically thin sheet or a few layered sheets (e.g., about 20 or less) of fused six- membered rings forming an extended sp2-hybridized carbon planar lattice.
  • Graphene-based materials include, but are not limited to, single layer graphene, multilayer graphene or interconnected single or multilayer graphene domains and combinations thereof.
  • graphene material may refer to graphene or a graphene-based material.
  • graphene-based materials also include materials which have been formed by stacking single or multilayer graphene sheets.
  • multilayer graphene includes 2 to 20 layers, 2 to 10 layers or 2 to 5 layers. In some embodiments, layers of multilayered graphene are stacked, but are less ordered in the z direction (perpendicular to the basal plane) than a thin graphite crystal.
  • a sheet of graphene-based material is a sheet of single or multilayer graphene or a sheet comprising a plurality of interconnected single or multilayer graphene domains.
  • the multilayer graphene domains have 2 to 5 layers or 2 to 10 layers.
  • a "domain" refers to a region of a material where atoms are uniformly ordered into a crystal lattice. A domain is uniform within its boundaries, but different from a neighboring region. For example, a single crystalline material has a single domain of ordered atoms.
  • At least some of the graphene domains are nanocrystals, having a domain size from 1 nm to 100 nm, such as 10 nm to 100 nm. In some embodiments, at least some of the graphene domains have a domain size greater than 100 nm to 1 micron, or from 200 nm to 800 nm, or from 300 nm to 500 nm. In some embodiments, a domain of multilayer graphene may overlap a neighboring domain. "Grain boundaries" formed by crystallographic defects at edges of each domain differentiate between neighboring crystal lattices.
  • a first crystal lattice may be rotated relative to a second crystal lattice, by a rotation about an axis perpendicular to the plane of a sheet, such that the two lattices differ in "crystal lattice orientation.”
  • the sheet of graphene-based material is a sheet of single or multilayer graphene or a combination thereof.
  • the sheet of graphene-based material is a sheet comprising a plurality of interconnected single or multilayer graphene domains. The interconnected domains may be covalently bonded together to form the sheet. When the domains in a sheet differ in crystal lattice orientation, the sheet may be considered polycrystalline.
  • the thickness of the sheet of graphene-based material is from 0.3 nm to 10 nm, such as from 0.34 nm to 10 nm, from 0.34 nm to 5 nm, or from 0.34 nm to 3 nm. In some embodiments, the thickness may include both single layer graphene and non- graphenic carbon.
  • graphene is the dominant material in a graphene-based material.
  • a graphene-based material may comprise at least 20% graphene, such as at least 30% graphene, at least 40% graphene, at least 50% graphene, at least 60% graphene, at least 70%) graphene, at least 80% graphene, at least 90% graphene, at least 95% graphene, or more.
  • a graphene-based material may comprise a graphene content range selected from 30% to 100%, such as from 30% to 95%, such as from 40% to 80%, from 50% to 70%, from 60% to 95%, or from 75% to 100%.
  • the amount of graphene in the graphene-based material is measured as an atomic percentage.
  • the amount of graphene in the graphene-based material is measured as an atomic percentage utilizing known methods including transmission electron microscope examination or, alternatively, if TEM is ineffective, another similar measurement technique.
  • a sheet of graphene-based material may further comprise non- graphenic carbon-based material located on at least one surface of the sheet of graphene-based material.
  • the sheet is defined by two base surfaces (e.g. top and bottom faces of the sheet) and side faces (e.g. the side faces of the sheet).
  • non- graphenic carbon-based material is located on one or both base surfaces of the sheet.
  • the sheet of graphene-based material includes a small amount of one or more other materials on the surface, such as, but not limited to, one or more dust particles or similar contaminants.
  • the amount of non-graphenic carbon-based material is less than the amount of graphene. In some other embodiments, the amount of non-graphenic carbon material is three to five times the amount of graphene; this may be measured in terms of mass. In additional embodiments, the non-graphenic carbon material is characterized by a percentage by mass of said graphene-based material selected from the range of 0% to 80%. In some
  • the surface coverage of the sheet of non-graphenic carbon-based material is greater than zero and less than 80%, such as from 5% to 80%, from 10% to 80%, from 5% to 50%), or from 10%> to 50%. This surface coverage may be measured with transmission electron microscopy.
  • the amount of graphene in the graphene-based material is from 60%) to 95% or from 75% to 100%. The amount of graphene in the graphene-based material is measured as mass percentage utilizing known methods, preferentially using transmission electron microscopy (TEM) examination or, alternatively, if TEM is ineffective, using other similar techniques.
  • TEM transmission electron microscopy
  • the non-graphenic carbon-based material does not possess long range order and may be classified as amorphous.
  • the non-graphenic carbon-based material may further comprise elements other than carbon and/or hydrocarbons.
  • non-carbon elements which may be incorporated in the non-graphenic carbon include hydrogen, oxygen, silicon, copper, and iron.
  • the non-graphenic carbon-based material comprises hydrocarbons.
  • carbon is the dominant material in non- graphenic carbon-based material.
  • a non-graphenic carbon-based material may comprise at least 30% carbon, such as at least 40% carbon, at least 50% carbon, at least 60% carbon, at least 70% carbon, at least 80% carbon, at least 90% carbon, or at least 95% carbon.
  • a non-graphenic carbon-based material comprises a range of carbon selected from 30% to 95%, such as from 40% to 80%, or from 50% to 70%.
  • the amount of carbon in the non-graphenic carbon-based material may be measured as an atomic percentage utilizing known methods preferentially using transmission electron microscope examination or, alternatively, if TEM is ineffective, using other similar techniques.
  • the graphene material may be in the form of a macroscale sheet.
  • a macroscale sheet may be observable by the naked eye.
  • at least one lateral dimension of the macroscopic sheet may be greater than 1 mm, such as greater than 5 mm, greater than 1 cm, or greater than 3 cm.
  • the macroscopic sheet may be larger than a flake obtained by exfoliation.
  • the macroscopic sheet may have a lateral dimension greater than about 1 micrometer.
  • the lateral dimension of the macroscopic sheet may be less than 10 cm.
  • the macroscopic sheet may have a lateral dimension of from 10 nm to 10 cm, such as from 1 mm to 10 cm.
  • a lateral dimension is generally perpendicular to the thickness of the sheet.
  • two-dimensional material may refer to any extended planar structure of atomic thickness, including both single- and multi-layer variants thereof.
  • Multi-layer two-dimensional materials may include up to about 20 stacked layers.
  • a two-dimensional material suitable for the present structures and methods can include any material having an extended planar molecular structure and an atomic level thickness.
  • Particular examples of two-dimensional materials include graphene films, graphene- based material, transition metal dichalcogenides, metal oxides, metal hydroxides, graphene oxide, hexagonalboron nitride, silicone, germanene, or other materials having a similar planar structure.
  • transition metal dichalcogenides include molybdenum disulfide and niobium diselenide.
  • metal oxides include vanadium pentoxide.
  • Graphene or graphene-based films according to the embodiments herein can include single-layer or multi-layer films, or any combination thereof. Choice of a suitable two-dimensional material can be determined by a number of factors, including the chemical and physical environment into which the graphene, graphene-based material or other two-dimensional material is to be terminally deployed, ease of perforating the two-dimensional material, and the like. The processes and structures disclosed herein with respect to graphene materials are also applicable to two-dimensional materials.
  • Pores as described herein may be sized to provide desired selective permeability of a species (atom, molecule, protein, virus, cell, etc.) for a given application.
  • Selective permeability relates to the propensity of a porous material or a perforated two-dimensional material to allow passage (or transport) of one or more species more readily or faster than other species.
  • Selective permeability allows separation of species which exhibit different passage or transport rates.
  • selective permeability correlates to the dimension or size (e.g., diameter) of apertures and the relative effective size of the species.
  • Selective permeability of the perforations in two-dimensional materials such as graphene-based materials can also depend on functionalization of perforations (if any) and the specific species that are to be separated.
  • Separation of two or more species in a mixture includes a change in the ratio(s) (weight or molar ratio) of the two or more species in the mixture after passage of the mixture through a perforated two-dimensional material.
  • a characteristic size of the pores may be from 0.3 nm to 500 nm, such as from 0.3 nm to 10 nm, from 1 nm to 10 nm, from 5 nm to 10 nm, from 5 nm to 20 nm, from 10 nm to 50 nm, from 50 nm to 100 nm, from 50 nm to 150 nm, from 100 nm to 200 nm, or from 100 nm to 500 nm.
  • the characteristics size may refer to the average pore size. In some embodiments, from 70% to 99%, such as from 80% to 99%, from 85% to 99%, or from 90% to 99%), of the pores in a sheet or layer fall within a specified range, and the remaining pores fall outside the specified range.
  • the size distribution of the pores may be narrow, e.g., limited to 0.1 to 0.5 coefficient of variation.
  • the characteristic dimension may be the diameter of the hole.
  • the characteristic dimension may be the largest distance spanning the hole, the smallest distance spanning the hole, the average of the largest and smallest distance spanning the hole, or an equivalent diameter based on the in-plane area of the pore.
  • Quantitative image analysis of pore features may include measurement of the number, area, size and/or perimeter of pores.
  • d is the equivalent diameter of the pore
  • A is the area of the pore.
  • the coefficient of variation of the pore size may be calculated herein as the ratio of the standard deviation of the pore size to the mean of the pore size.
  • the ratio of the area of the pores to the area of the sheet is used to characterize the sheet.
  • the area of the sheet may be taken as the planar area spanned by the sheet.
  • characterization may be based on the ratio of the area of the perforations to the sheet area excluding features such as surface debris.
  • characterization may be based on the ratio of the area of the pores to a suspended area of the sheet.
  • the pore area may comprises 0.1% or greater, such as 1%) or greater, or 5% or greater of the sheet area.
  • the pore are may comprise less than 15% of the sheet area, such as less than 10% of the sheet area.
  • the pore area may comprise from 0.1% to 15% of the sheet area, such as from 1% to 15%) of the sheet area, from 5%> to 15%> of the sheet area, or from 1%> to 10%> of the sheet area.
  • the pores may be located over greater than 10%>, such as greater than 15%> of the area, of a sheet of graphene-based material.
  • the pore density may be from 2 pores pre nm 2 to 1 pore per ⁇ 2 .
  • the defect repair process includes the application of a first reactant to a first side of the graphene material and a second reactant to a second side of the graphene material.
  • molecules of the first reactant material 3110 are disposed on a first side of the graphene material 2900 and molecules of the second reactant material 3120 are disposed on a second side of the graphene material 2900.
  • a defect 2912 in the graphene material 2900 allows the first reactant 3110 to contact the second reactant 3120 as shown in FIG. 38.
  • the first reactant 3110 and the second reactant 3120 may pass through any defect 2912 with a size larger than the reactant molecules.
  • the interaction between the first reactant 3110 and the second reactant 3120 produces a polymerization reaction and forms a polymer 3110 in the defect.
  • the polymerization reaction may continue until the polymer 3110 fills the defect and the first reactant 3110 and second reactant 3120 are no longer able to pass through the defect and interact.
  • the thickness of the polymer region may depend on the type of polymer employed and the reaction conditions. In some embodiments the thickness of the polymer region may be greater than a few nanometers, such as greater than 3 nm, greater than 10 nm, greater than 25 nm, greater than 50 nm, greater than 100 nm, greater than 1 ⁇ m, greater than 10 ⁇ m, greater than 100 ⁇ m, or more. In some embodiments, the polymer regions may have a thickness in the range of 3 nm to 100 ⁇ m, such as from 10 nm to 50 ⁇ m, or from 10 nm to 500 nm.
  • the first reactant may be any reactant capable of producing a polymer when in contact with the second reactant.
  • the first reactant may be provided in the form of a liquid solution or suspension.
  • the first reactant may be a monomer or oligomer.
  • the monomer or oligomer may include a diamine, such as hexamethylene diamine, or a polystyrene monomer.
  • the first reactant may be biocompatible or bio-inert.
  • the second reactant may be any reactant capable of producing a polymer when in contact with the first reactant.
  • the second reactant may be provided in the form of a liquid solution, liquid suspension, gas, or plasma.
  • the second reactant may be a monomer, an oligomer, or a catalyst that initiates polymerization.
  • the second reactant may be a dicarboxylic acid, such as hexanedioic acid.
  • the second reactant may be a polymerization catalyst, such as azobisisobutyronitrile (AIBN).
  • AIBN azobisisobutyronitrile
  • the second reactant may be provided in an aqueous solution or an oil based solution.
  • the second reactant may be
  • the reactants may be selected from monomers or oligomers that include any of the following functional groups: hydroxyl, ether, ketone, carboxyl, aldehyde, amine, or combinations thereof.
  • the monomers or oligomers may be selected from any appropriate species that includes a functional group capable of reacting with a counterpart reactant to produce a polymer.
  • the reactants may be selected to produce a step or condensation polymerization.
  • a step or condensation polymerization reaction is self-limiting, as once the defects are filled such that the reactants can no longer pass through the defect the polymerization reaction will cease due to a lack of reactants.
  • the self-limiting nature of the step or condensation polymerization reaction allows the defects in the graphene material to be fully repaired without concern that polymer formation will continue until pores and desired fluid flow channels are blocked.
  • the reactants may be selected to produce an addition or chain polymerization reaction.
  • one of the reactants may be a monomer, oligomer, or polymer and the second reactant may be an initiator.
  • the addition or chain polymerization reaction may continue until the reaction is quenched or the reactant supply is exhausted.
  • the extent of the addition or chain polymerization may be controlled by quenching the reaction after a predetermined time that is selected to ensure that sufficient repair of the defects in the graphene material has occurred.
  • the quenching of the reaction may be achieved by introducing a quenching reagent, such as oxygen, to the reaction system.
  • An addition or chain polymerization reaction may be useful in applications where it is desirable for the polymer to be formed in areas beyond the immediate defects of the graphene material.
  • the ability to form more extensive polymer regions allows the interfacial polymerization process to produce polymer regions with additional functionality, such as providing adhesion enhancements, mechanical reinforcement, or chemical functionalization.
  • An exemplary reactant pair for an addition or chain polymerization may be an AIBN aqueous solution and a vapor phase polystyrene.
  • the polymer formed during the repair process may be any appropriate polymer.
  • the polymers formed utilizing a step or condensation polymerization reaction may include polyamide, polyimide, polyester, polyurethane, polysiloxane, phenolic resin, epoxy, melamine, polyacetal, polycarbonate, and co-polymers thereof.
  • the polymers formed utilizing an addition or chain polymerization reaction may include polyacrylonitrile, polystyrene, poly(methyl methacrylate), poly(vinyl acetate), or co-polymers thereof.
  • the polymer formed during the repair process may be a biocompatible or bio-inert polymer.
  • the polymer formed during the repair process may be semipermeable, such that some materials or molecules may diffuse through the polymer regions that fill the defects.
  • the polymer may be porous or non-porous.
  • the first reactant and the second reactant may have a size larger than a desired pore size of the graphene material.
  • the use of reactants with such a size allows for the selective repair of only those defects that have a size greater than the desired pore size, as the reactants are unable to pass through the defects and pores with a size less than the desired pore size of the graphene material.
  • the size of a defect may refer to the effective diameter of the defect.
  • the effective diameter of a defect is the diameter of the largest spherical particle that will pass through the defect. The effective diameter may be measured by any appropriate method, such as imaging with a scanning electron microscope and then calculating the effective diameter of the defect.
  • the size of a reactant may refer to the effective diameter of the reactant.
  • the effective diameter of the reactant may be the diameter of a sphere that is capable of passing through the same openings that the reactant can pass through.
  • the effective diameter of polymeric materials may refer to the diameter of gyration, with the diameter of gyration being twice the radius of gyration.
  • a reactant with a large size may be a dendrimer.
  • the dendrimers may include a surface containing any of the functional groups described herein for the reactants.
  • the dendrimers may include hydroxyl, amine, sulfonic acid, carboxylic acid, or quaternary ammonium functional groups on the surface thereof.
  • the large reactants may have a size of at least about 15 nm, such as at least about 20 nm, about 25 nm, about 30 nm, about 40 nm, about 50 nm, about 75 nm, about 100 nm, about 125 nm, or more.
  • a reactant with a large size may be a reactant with a diameter of gyration that is equivalent to the effective diameter of the smallest defect targeted for repair.
  • Exemplary reactants of this type may include high molecular weight polymers with end groups including the functional groups described above for the reactants.
  • a large reactant may be an ionic polymer, where the first and second reactants are selected to have opposite charges.
  • the graphene material 2900 may include defects 2912 and pores 2914. The use of a first reactant material 3110 and a second reactant material 3120 with a size greater than the size of the pores 2914 prevents the reactant molecules from passing through and polymerizing in the pores 2914.
  • the first reactant material 3110 and the second reactant material 3120 pass through and polymerize in the defects 2912.
  • the interfacial polymerization repair process is capable of selectively repairing only those defects having a size that is greater than a desired pore size.
  • the defects are filled by a polymer region 110, while the pores 2914 are open and allow the passage of fluid there through.
  • the first reactant material and the second reactant material are provided in forms that allow the manner in which the reactants diffuse into each other to be controlled.
  • the way in which the reactants interact influences the location of the polymer produced by the polymerization.
  • the reactants are provided in a form that does not allow significant amounts of diffusion of either reactant in to the other, which produces a polymer region that has a midpoint that substantially aligns with the graphene material, as shown in FIG. 34.
  • the reactants may be provided in solutions that are immiscible with each other, such that the interface between the solutions is maintained along the plane of the graphite material.
  • the immiscible solutions may be any appropriate combination, such as an aqueous solution and an oil-based solution.
  • the diffusion of the reactants in to the other reactant solution may be prevented by selecting reactants that are not soluble in the solvent forming the other solution.
  • a first reactant that is not soluble in oil may be provided in an aqueous solution and a second reactant that is not soluble in water may be provided in an oil solution, producing limited or no diffusion of the reactants to the counterpart solution.
  • the first reactant and second reactant may be selected such that one of the reactants is cationic and the second reactant is anionic.
  • the reactants may be selected such that one of the reactants is capable of diffusing readily into the other reactant.
  • the first reactant material 3110 may be selected such that the second reactant material 3120 diffuses therein, producing a polymer 3110 that is located substantially on the side of the graphene material 2900 that the first reactant is disposed on.
  • a similar effect may be produced when the first reactant is a liquid solution and the second reactant is a gas, such that the first reactant does not diffuse in to the gas of the second reactant.
  • the second reactant material 3120 may be selected such that the first reactant material 3110 diffuses in the second reactant material 3120.
  • a reactant system of this type produces a polymer 3110 that is located substantially on the side of the graphene material 2900 on which the second reactant material 3120 is disposed, as shown in FIG. 36.
  • the interaction of the reactants through the defects in the graphene material may be the result of diffusion.
  • the reactants may be heated to increase the diffusion thereof and the likelihood that the reactants will interact.
  • the reactants may be ionic, with the first and second reactants having opposite charges. The opposite charges of the ionic polymers produces an attraction between the reactants, ensuring that the reactants interact across the defects of the graphene material to produce a polymer.
  • electrophoresis may be employed to facilitate interaction between ionic and polar reactants.
  • the reactants may have a dipole, such that an electric or magnetic field may be applied to the reactants to drive motion of the reactants in the system and produce interaction between the reactants.
  • an electrical potential may be applied across the graphene material, attracting the reactants to the surface thereof and enhancing interaction between the reactants.
  • the polymer regions formed in the defects may be attached to the graphene material by any suitable interaction.
  • the polymer regions may be attached to the graphene material through mechanical interaction.
  • One example of mechanical interaction occurs includes a polymer region formed such that the portion of the polymer region in plane with the graphene material is has a smaller dimension than the portions of the polymer region formed on either side of the graphene material.
  • the larger ends of the polymer region mechanically interact with the graphene material to prevent the polymer region from being pulled out of the defect.
  • the graphene material and the polymer region may be attached by van der Waals attraction.
  • the graphene material may be functionalized to produce covalent or non-covalent interactions between the graphene material and the polymer regions.
  • the graphene material may be rendered hydrophobic or hydrophilic by treating the graphene material before forming the polymer regions, such that the interaction between the graphene material and the polymer region is strengthened.
  • the graphene material may be treated to form functional groups, such as hydroxyl, carbonyl, carboxylic, or amine groups. The functionalization may be achieved through any appropriate process, such as oxidation of the graphene material.
  • the graphene material may be oxidized by thermal treatment, ultraviolet oxidation, plasma treatment, sulfuric acid treatment, nitric acid treatment, or permanganate treatment.
  • the graphene material may be aminated by ammonia treatment. The oxidation may be limited to the area of the graphene material containing defects, as the chemical bonds of the graphene material are generally more reactive in the areas adjacent to defects than in the basal plane.
  • the functional groups produced by the treatment of the graphene material may form covalent bonds with the polymer regions, such that the polymer regions are attached to the graphene material by the covalent bonds.
  • the reactants may be selected such that the produced polymer is capable of adhering to a support over which the graphene material may be disposed.
  • graphene materials do not covalently bond to support materials, thus by selecting a polymer material to repair defects in the graphene material that will adhere to a support structure the adhesion of the repaired graphene material to the support structure may be improved.
  • the increased adhesion may be demonstrated by immersing the sample in a solvent that does not attack the polymer regions or the support structure and agitating the sample.
  • the increased adhesion may be demonstrated by applying a back pressure to the support structure side of the graphene material, and measuring the delamination/rupture pressure. The materials exhibiting improved adhesion have a higher delamination/rupture pressure than graphene materials that lack the polymer regions.
  • the support structure may be any appropriate structure that supports the graphene material without hindering the desired applications of the graphene material, such as filtration or selective permeability.
  • the support structure may be a polymer material, such as a polycarbonate material. In the case that the support is a polycarbonate material, the polymer may be an epoxy.
  • the support may be a porous material, such that the graphene material is supported while also allowing fluid to flow to and through the graphene material.
  • a porous material that may be useful as a support structure for the graphene material may include one or more selected from ceramics and thin film polymers.
  • ceramic porous materials may include silica, silicon, silicon nitride, and combinations thereof.
  • the porous material may include track-etched polymers, expanded polymers, patterned polymers, non-woven polymers, woven polymers, and combinations thereof.
  • the support structure may include a polymer selected from the group consisting of polysulfones, polyurethane, polymethylmethacrylate (PMMA), polyethylene glycol (PEG), polylactic-co-glycolic acid (PLGA), PLA, PGA, polyamides (such as nylon-6,6, supramid and nylamid), polyimides, polypropylene, polyethersulfones (PES), polyvinylidine fluoride (PVDF), cellulose acetate, polyethylene, polypropylene, polycarbonate, polytetrafluoroethylene (PTFE) (such as Teflon), polyvinylchloride (PVC), polyether ether ketone (PEEK), mixtures and block co-polymers of any of these, and combinations and/or mixtures thereof.
  • the polymers are biocompatible, bioinert and/or medical grade materials.
  • the repaired graphene material may be adhered to the support structure material by placing the repaired graphene material in contact with the support structure material.
  • the support structure may be treated to promote adhesion to the polymer regions of the repaired graphene material.
  • the adhesion promoting treatment may include any appropriate process, such as subjecting the surface of the support structure to ultra violet oxidation.
  • the graphene material 4000 may be separated from the support structure material 4050 by a gap as a result of the thickness and location of the polymer regions 4012 repairing the defects and polymer handling region 4040. The size of the gap may be controlled by altering the location of the polymer regions formed during the repair process, as described above.
  • the increase in adhesion of the repaired graphene material to the support structure is a function of the proportion of polymer regions in the repaired graphene material.
  • a minimum amount of polymer regions, and thereby adhesion may be ensured by forming holes in the graphene layer before the repair process.
  • holes refer to openings purposefully formed in the graphene material that will be plugged by the polymer material during the repair process.
  • the holes may fall within the defect classification, as they are undesired in the repaired membrane material.
  • the holes may have any appropriate size, such as any of the sizes of the pores described herein.
  • the holes may have a size that is greater than the desired pore size, such that the holes may be filled during the repair process and the pores may remain open.
  • the holes may be formed in the graphene material by any appropriate process, such as ion bombardment, chemical reaction, nanoparticle impacting or mechanical cutting. In some embodiments, the holes may be formed by any of the processes described herein for the formation of pores in the material.
  • the holes may be arranged in a periodic array with a predetermined pattern and spacing across the surface of the graphene material. As shown in FIG. 39, the holes may be arranged in a plurality of rows, with a defined spacing between holes within each row, and a defined spacing between rows. The spacing of the holes in the rows may be the same in multiple rows, or different in each row.
  • the spacing between the rows may be uniform, such that the spacing between each adjacent pair of rows is the same, or varied, such that the spacing between pairs of adjacent rows may be different.
  • the spacing of the holes in adjacent rows may be in phase, such that the holes in adjacent rows are aligned, as shown in FIG. 39. In some other embodiments, the spacing of the holes in the rows may be out of phase, such that the holes in adjacent rows are not aligned.
  • the holes may be arranged in a repeating pattern. In some embodiments, the holes may have a random distribution across the surface of the graphene material.
  • the holes may be formed such that the holes account for at least about 5% of the area of the graphene material before repair, such as at least about 10%, about 15%), about 20%, about 25%, about 30%>, about 40%, or more. In some embodiments, the holes may have an area of less than about 50% of the area of the graphene material before repair, such as less than about 45%, about 40%, about 35%, about 30%, about 25%, about 20%, or less. The minimum area of the holes of the graphene material may be selected such that the polymer regions of the repaired graphene material produce at least a desired degree of adhesion between the repaired graphene material and the support structure.
  • the adhesion between the repaired graphene material and the support structure produces a graphene membrane assembly.
  • the adhesion between the polymer regions of the repaired graphene material and the support structure may include van der Waals forces, chemical bonds, molecular entanglement, or combinations thereof.
  • the polymer of the polymer regions may include polar a group, such as a hydroxyl, carbonyl, amine, epoxide, or combinations thereof, that exhibits stronger van der Waals attraction to the support structure than the graphene material.
  • the polymer of the polymer regions may include functional groups or side chains that readily react with the support structure to form chemical bonds.
  • the chemical bonding between the polymer regions and the support structure may be initiated by any appropriate process, such as exposure to ultraviolet (UV) radiation, thermal treatment, or combinations thereof.
  • the polymer molecules of the polymer regions may be entangled with polymer molecules of the support structure.
  • the molecular entanglement may be produced by thermal treatment of the graphene membrane assembly, such that the polymer of the polymer region and the support structure are softened without degrading.
  • the polymer of the polymer region and the polymer of the support structure may be selected to have similar thermal properties, such that both polymers are softened sufficiently at the treatment temperature to produce entanglement of the polymer molecules.
  • the graphene membrane assembly exhibits improved performance and service life when compared to a graphene membrane without polymer adhesion regions disposed on support structures.
  • the polymer regions may be adhered to a support structure in a manner that increases the surface area of the graphene material provided on the support structure.
  • polymer regions 4812 of a repaired graphene material may be adhered to a support structure 4850 such that the graphene material 4800 forms folds, drapes, or bends that increase the available surface area of the graphene material.
  • the increased surface area may be produced by adhering the polymer regions 4812 to the support structure 4850 such that the distance between the polymer regions on the support structure is less than the length of the graphene material between the polymer regions.
  • the graphene material may then fold or bend to accommodate the shorter distance between the polymer regions, and produce an increased graphene surface area for a given support structure area.
  • the folds, drapes, or bends may be formed by performing the repair process in a solvent that induces swelling in the polymer, and then exchanging the solvent for another solvent that does not swell the polymer.
  • the resulting shrinkage of the polymer regions may relax the graphene and create folds, drapes, or bends therein.
  • the polymer regions may be softened by heating to relieve stress in the polymer material, creating folds, drapes, or bends in the graphene material.
  • movements of the repaired graphene material that includes the polymer regions may produce the folds, drapes, or bends in the graphene material.
  • the support structure may be formed in situ during the repair process.
  • holes may be formed in the graphene material in a pattern and spacing that will result in an interconnected polymer layer, while still maintaining an area of the graphene material sufficient to allow the desired performance of the graphene material.
  • the holes may be produced utilizing any of the procedures described herein, and with any of the shapes and sizes described herein.
  • the holes may be formed in any appropriate pattern, and with any appropriate size.
  • the holes may be formed in linear arrangements such that the distance between the holes is significantly smaller than the size of the holes.
  • the holes may be arranged in lines, circles, squares, or any other appropriate pattern. As shown in FIG.
  • the holes 4510 may be formed in the graphene material 4480 in a series of lines, where the spacing between the holes within the lines is small in comparison to the size of the holes.
  • the polymer may grow beyond the beyond the borders of the holes, such that the formed polymer regions associated with each hole fuse or merge together, producing a substantially continuous support structure.
  • the in situ formed polymer support structure may include a polymer handling region 4540 fused with the polymer regions 4412 formed in the holes.
  • FIG. 47 shows that portions of the polymer regions filling the holes 4412 and/or polymer handling regions 4540 may extend over portions of the graphene material 4480 to fuse and form a substantially continuous in situ support structure.
  • the in situ support structure may resemble a porous polymer layer, with the graphene material extending across the pores in the support structure.
  • the in situ support structure may be produced by disposing a porous layer over the graphene membrane prior to forming the in situ support structure, and removing the porous layer after the formation of the in situ support to form fluid flow channels in the in situ support.
  • the porous layer may be a mesh, such as a polymer mesh. The removal of the porous layer may be achieved by any appropriate process, such as dissolving the porous layer.
  • the graphene material employed in the formation of the in situ support structure may be free of defects other than the holes produced for the purpose of forming the in situ support structure.
  • the repair process may be extended to produce a polymer handling region attached to the graphene material.
  • the polymer handling region 4040 may form a frame around the graphene material 4000 as shown in FIG. 31.
  • the polymer handling region 4040 may be formed in the same process and at the same time as the polymer regions 4012 that repair defects in the graphene material 4000.
  • the polymer handling region may be produced by extending the first reactant and the second reactant beyond the edges of the graphene material, such that the first and second reactants form a polymer extending from the edge of the graphene material.
  • the polymer handling region allows the repaired graphene material to be handled more easily, as the polymer handling region may be more damage resistant than the graphene material.
  • the polymer handling region allows the repaired graphene material to be manipulated without directly contacting the graphene material, reducing the opportunity for defects to form in the graphene material after the repair process.
  • the repair process may be utilized to form a polymer handling region on a graphene material that is free of defects.
  • the polymer handling region may have any appropriate size and geometry. As shown in FIG. 41, the polymer handling region 4040 may be in the form of a substantially continuous border that extends along the circumference of the graphene material 4000. The polymer handling region may extend for a distance of at least about 1 mm from the edge of the graphene material, such as at least about 2 mm, about 5 mm, about 1 cm, about 2 cm, about 5 cm, or more. The polymer handling region may have a thickness on the same scale as the polymer regions that plug defects in the graphene material described herein. In some embodiments, the polymer handling region has the same thickness as the polymer regions that plug defects in the graphene material. In some embodiments, the polymer handling region may extend along at least a portion of an edge of the graphene region, such as along one or more edges of the graphene material.
  • the polymer handling region 4040 may also function as a sealing region that prevents fluid from flowing around the edges of the graphene material.
  • the polymer handling region may be adhered and sealed to a support structure 4050, as shown in FIG. 42.
  • the polymer handling region may be utilized to mount the graphene material in a device or test fixture.
  • the polymer handling region 4342 of a first repaired graphene material 4302 may be sealed to the polymer handling region 4344 of a second repaired graphene material 4304 to form a graphene enclosure or envelope, as shown in FIGS. 43 and 44.
  • the graphene enclosure or envelope forms an interior volume 4370 that is defined by the first graphene material 4302 and the second graphene material 4304.
  • the polymer repair process may be conducted before or after forming pores in the graphene material.
  • the repair process may employ reactants with a size selected to repair only defects greater in size than the desired pores, as described above. In this manner the desired pores are maintained in the repaired graphene material, while defects larger than the desired pore size are repaired with a polymer region. Performing the repair process after forming the pores allows for pore forming procedure that results in a less controlled pore size to be employed, as pores formed that are larger than the desired size will be repaired.
  • defects may be formed in the graphene material during the pore forming process and repairing the graphene material after the pore forming process prevent defects formed in the pore forming process from being present in the finished material. This produces a graphene material with more uniform pore sizes.
  • the process of producing a perforated graphene material may include forming pores in a graphene material, forming holes in the graphene material to increase adhesion of the graphene material to a substrate, and repairing the graphene material utilizing an interfacial polymerization process.
  • the graphene material 3900 includes pores 3930, holes 3910 and defects 3920, as shown in FIG. 39.
  • the graphene material 3900 includes pores 3930, polymer regions filling the defects 3922, and polymer regions filling the holes 3912, as shown in FIG. 40.
  • the repaired graphene material may be free of defects and holes that are larger than the desired pore size.
  • the forming of the holes in the graphene material is an optional step, and may not be performed where an increase in adhesion between the graphene material and a substrate is not desired.
  • a process without the formation of holes may produce a graphene material 4000 that includes pores 3930, a polymer region filling defects 4012, and a polymer handling region 4040.
  • the graphene material may be produced by repairing defects in the graphene material with interfacial polymerization and forming pores in the material by any appropriate process.
  • pores may be formed in the graphene material by ultraviolet oxidation, plasma treatment, ion irradiation, or nanoparticle bombardment. The pore formation may occur before or after the repair of the graphene material.
  • Ion-based perforation processes may include methods in which the graphene-based material is irradiated with a directional ion source.
  • the ion source is collimated.
  • the ion source may be a broad field or flood ion source.
  • a broad field or flood ion source can provide an ion flux which is significantly reduced compared to a focused ion beam.
  • the ion source inducing perforation of the graphene or other two-dimensional material in embodiments of the present disclosure is considered to provide a broad ion field, also commonly referred to as an ion flood source.
  • the ion flood source does not include focusing lenses.
  • the ion source may be operated at less than atmospheric pressure, such as at 10 -3 to 10 -5 torr or 10 -4 to 10 -6 torr.
  • the environment may also contain background amounts (e.g. on the order of 10 -5 torr) of oxygen (02), nitrogen (N2) or carbon dioxide (C02).
  • the ion beam may be perpendicular to the surface of the layer(s) of the material (incidence angle of 0 degrees) or the incidence angle may be from 0 to 45 degrees, 0 to 20 degrees, 0 to 15 degrees or 0 to 10 degrees.
  • exposure to ions does not include exposure to a plasma.
  • Ultraviolet oxidation based perforation processes may include methods in which the graphene-based material is simultaneously exposed to ultraviolet (UV) light and an oxygen containing gas. Ozone may be generated by exposure of an oxygen containing gas such as oxygen or air to the UV light. Ozone may also be supplied by an ozone generator device. In some embodiments, the UV oxidation based perforation method further includes exposure of the graphene-based material to atomic oxygen. Suitable wavelengths of UV light may include, but are not limited to, wavelengths below 300 nm, such as from 150 nm to 300 nm.
  • the intensity of the UV light may be from 10 to 100 mW/cm 2 at 6 mm distance or 100 to 1000 mW/cm 2 at 6 mm distance.
  • suitable UV light may be emitted by mercury discharge lamps (e.g. a wavelength of about 185 nm to 254 nm).
  • UV oxidation is performed at room temperature or at a temperature greater than room
  • UV oxidation may be performed at atmospheric pressure (e.g. 1 atm) or under vacuum.
  • the pores may be formed by nanoparticle bombardment.
  • Nanoparticle bombardment may employ a nanoparticle beam or a cluster beam.
  • the beam is collimated or is not collimated.
  • the beam need not be highly focused.
  • a plurality of the nanoparticles or clusters is singly charged.
  • the nanoparticles comprise from 500 to 250,000 atoms, such as from 500 to 5,000 atoms.
  • metal particles are suitable for use in the methods of the present disclosure.
  • nanoparticles of Al, Ag, Au, Ti, Cu and nanoparticles comprising Al, Ag, Au, Ti, Cu are suitable.
  • Metal Ps can be generated in a number of ways including magnetron sputtering and liquid metal ion sources (LMIS). Methods for generation of nanoparticles are further described in Cassidy, Cathal, et al. "Inoculation of silicon nanoparticles with silver atoms.” Scientific reports 3 (2013), Haberland, Hellmut, et al.
  • Gas cluster beams can be made when high pressure gas adiabatically expands in a vacuum and cools such that it condenses into clusters. Clusters can also be made ex situ such as C60 and then accelerated towards the graphene.
  • the nanoparticles are specially selected to introduce moieties into the graphene.
  • the nanoparticles function as catalysts.
  • the moieties may be introduced at elevated temperatures, optionally in the presence of a gas.
  • the nanoparticles introduce" chiseling" moieties, which are moieties that help reduce the amount of energy needed to remove an atom during irradiation.
  • the size of the produced pores is controlled by controlling both the nanoparticle size and the nanoparticle energy.
  • the size of the pore is believed to be influenced by deformation of the nanoparticle during the perforation process. This deformation is believed to be influenced by both the energy and size of the nanoparticle and the stiffness of the graphene layer(s). A grazing angle of incidence of the nanoparticles can also produce deformation of the nanoparticles.
  • the nanoparticle energy it is believed that nanoparticles can be deposited with a large mass and size distribution, but that a sharp cutoff can still be achieved.
  • the mechanism of perforation is believed to be a continuum bound by sputtering on one end (where enough energy is delivered to the graphene sheet to atomize the carbon in and around the NP impact site) and ripping or fracturing (where strain induced failure opens a torn hole but leaves the graphene carbons as part of the original sheet).
  • Part of the graphene layer may fold over at the site of the rip or fracture.
  • the cluster can be reactive so as to aid in the removal of carbon (e.g. an oxygen cluster or having trace amounts of a molecule known to etch carbon in a gas cluster beam i.e. a mixed gas cluster beam).
  • the stiffness of a graphene layer is believed to be influenced by both the elastic modulus of graphene and the tautness of the graphene.
  • Factors influencing the elastic modulus of a graphene layer are believed to include temperature, defects (either small defects or larger defects from P irradiation), physisorption, chemisorption and doping.
  • Tautness is believed to be influenced by coefficient of thermal expansion mismatches (e.g. between substrate and graphene layer) during deposition, strain in the graphene layer, wrinkling of the graphene layer.
  • strain in a graphene layer can be influenced by a number of factors including application of gas pressure to the backside (substrate side) of a graphene layer, straining of an elastic substrate prior to deposition of graphene, flexing of the substrate during deposition, and defecting the graphene layer in controlled regions to cause the layer to locally contract and increase the local strain.
  • nanoparticle perforation can be further controlled by straining the graphene layers during perforation to induce fracture, thereby "ripping" or “tearing" one or more graphene layers.
  • the stress is directional and used to preferentially fracture in a specific orientation. For example, ripping of one or more graphene sheets can be used to create "slit” shaped apertures; such apertures can be substantially larger than the nanoparticle used to initiate the aperture.
  • the stress is not oriented in a particular direction.
  • the pores may be functionalized.
  • the pores are functionalized by exposure to gas during and/or following the perforation process. The exposure to gas may occur at temperatures above room temperature.
  • the pores can have more than one effective functionalization. For example, when the top and the bottom layers of a graphite stack are exposed to different functionalizing gases, more than one effective functionalization can be produced.
  • a thin layer of a graphite stack are exposed to different functionalizing gases, more than one effective functionalization can be produced.
  • functionalizing moiety is applied to the surface before NP perforation, during NP perforation and after P perforation.
  • the thin layer may be formed by applying a fluid to the surface.
  • the gas pressure is 10 -4 Torr to atmospheric pressure.
  • functionalizing moieties include, but are not limited to water, water vapor, PEG, oxygen, nitrogen, amines, and carboxylic acid.
  • the preferred gasses for before and during functionalization depend on the reaction of graphene and the gas within the high energy environment of the particle impact. This would be within about 100 nm of the edge of the particle impact. This fits into two general classes, and the gases would be added at a partial pressure of from lx10 -6 Torr to lx10 -3 Torr.
  • the first class would be species that reacts with radicals, carbanions (negative charge centered on a carbon) and carbocations (positive charge centered on a carbon). Representative molecules include carbon dioxide, ethylene oxide and isoprene.
  • the second class would be species that fragment to create species that react with graphene and defective graphene. Representative molecules would be polyethylene glycol, diacytylperoxide, azobisisobutyronitrile, and phenyl diazonium iodide.
  • the process is stepwise efficient, since perforated single-layer graphene can optionally be produced by exfoliating the multi-layer graphene after the pore definition process is completed.
  • the pore size is also tailorable in the processes described herein.
  • the nanoparticle perforation processes described herein are desirable in terms of the number, size and size distribution of pores produced.
  • the multi -layer graphene subjected to nanoparticle perforation may contain between about 2 stacked graphene sheets and about 20 stacked graphene sheets. Too few graphene sheets may lead to difficulties in handling the graphene as well as an increased incidence of intrinsic or native graphene defects. Having more than about 20 stacked graphene sheets, in contrast, may make it difficult to perforate all of the graphene sheets.
  • the multilayer sheets may be made by individually growing sheets and making multiple transfers to the same substrate.
  • the multi-layer graphene perforated by the techniques described herein can have 2 graphene sheets, or 3 graphene sheets, or 4 graphene sheets, or 5 graphene sheets, or 6 graphene sheets, or 7 graphene sheets, or 8 graphene sheets, or 9 graphene sheets, or 10 graphene sheets, or 11 graphene sheets, or 12 graphene sheets, or 13 graphene sheets, or 14 graphene sheets, or 15 graphene sheets, or 16 graphene sheets, or 17 graphene sheets, or 18 graphene sheets, or 19 graphene sheets, or 20 graphene sheets.
  • the reactants may be applied to the graphene material by any appropriate process.
  • the graphene material may be disposed between liquid solutions or suspensions containing the reactants, and the liquid solutions and suspensions may or may not be flowing past the surfaces of the graphene material.
  • the liquid solutions or suspensions of reactants may be applied to the graphene material by rollers, brushes, spray nozzles, or doctor blades.
  • the reactants may be applied to the graphene material in droplet form, such as through the use of an inkjet apparatus.
  • a liquid solution or suspension containing a reactant may be disposed on one side of the graphene material and the other side of the graphene material may be exposed to a gas phase reactant.
  • the graphene material may be floated on the surface of a liquid suspension or solution containing one of the reactants.
  • the graphene material may be free of a support structure when it is floated on the liquid.
  • the graphene material may be disposed on a support structure when floated on the liquid, the support structure may include support structures that function to maintain the position of the graphene material on the surface of the liquid and support structures that may be utilized to handle the graphene material after repair.
  • a mesh material may be employed as a support structure to maintain the graphene material on the surface of the liquid.
  • a porous polymer may be employed as a support structure that may also be used to handle or manipulate the graphene material after the repair process.
  • a support structure including a sacrificial layer that is removed during or after the repair process may be employed.
  • the reactants may be applied to an enclosure or envelope including the graphene material.
  • an enclosure or envelope including the graphene material may include a lumen 4360 that allows access to the interior volume 4370 of the enclosure.
  • the first reactant may be supplied to the interior volume of the enclosure, and the second reactant may be applied to the exterior of the enclosure.
  • the manner of exposing the exterior of the enclosure to the second reactant may include any of the application processes described herein.
  • the first reactant may be removed from the enclosure and a desired component may be loaded in to the interior space of the enclosure.
  • the repaired graphene material described herein may be employed in any appropriate process or device.
  • the graphene material may be utilized in filtration devices, such as devices utilized in deionization, reverse osmosis, forward osmosis, contaminant removal, and wastewater treatment processes.
  • the graphene material may also be employed in a biomedical device as a selectively permeable membrane.
  • the graphene material may be employed in a viral clearance or protein separation process.
  • the graphene materials described herein may be employed as membranes in water filtration, immune-isolation (i.e., protecting substances from an immune reaction), timed drug release (e.g., sustained or delayed release), hemodialysis, and hemofiltration.
  • the graphene materials described herein may be employed in a method of water filtration, water desalination, water purification, immune-isolation, timed drug release, hemodialysis, or hemofiltration, where the method comprises exposing a membrane to an environmental stimulus.
  • methods of filtering water may include passing water through a membrane including the graphene materials described herein.
  • Some embodiments include desalinating or purifying water comprising passing water through a membrane including the graphene materials described herein.
  • the water can be passed through the membrane by any known means, such as by diffusion or gravity filtration, or with applied pressure.
  • Some embodiments include methods of selectively separating or isolating substances in a biological environment, wherein a membrane including the graphene materials described herein separates or isolates biological substances based on characteristics of the substance, such as size. Such methods can be useful in the context of disease treatment, such as in the treatment of diabetes.
  • biological substances below a certain size threshold can migrate across the membrane.
  • even biological substances below the size threshold are excluded from migrating across the membrane due to functionalization of membrane pores and/or channels.
  • Some embodiments relate to a two-dimensional membrane layered structure having a plurality of flow passages formed between a two-dimensional membrane layer and a support substrate layer.
  • the flow passages provide an increase in pore utilization by allowing fluid to flow through pores in the two-dimensional membrane layer that do not overlap with passages present in the support substrate. With the flow passages, fluid may flow from the non- overlapping pores through the flow passages to a nearby support substrate passage.
  • the flow passages may be formed by interlayer supports laterally disposed on an upper surface of the support substrate layer and/or by grooves laterally formed on the upper surface of the support substrate layer.
  • the flow passages may also provide sufficient support to the two-dimensional membrane without adding undesirable strain to the membrane layer.
  • FIG. 49 shows a perspective view of a two-dimensional membrane layered structure 4900.
  • the two-dimensional membrane layered structure 4900 may include a two-dimensional membrane layer 4910 having a plurality of pores 4915, and a support substrate layer 4920 having a plurality of substrate passages 4925 that extend along a thickness of the support substrate layer 4920.
  • the two-dimensional membrane layer 4910 may be a single-layer two-dimensional material or a stacked two-dimensional material. Most generally, a single-layer two dimensional material is atomically thin, having an extended planar structure and a thickness on the nanometer scale. Single-layer two-dimensional materials generally exhibit strong in-plane chemical bonding relative to the weak coupling present between layers when such layers are stacked. Examples of single-layer two-dimensional materials include metal chalcogenides (e.g., transition metal dichalcogenides), transition metal oxides, boron nitrate (e.g., hexagonal boron nitride), graphene, silicone, and germanene, carbon nanomembranes (CNM), and molybdenum disulfide.
  • metal chalcogenides e.g., transition metal dichalcogenides
  • transition metal oxides e.g., boron nitrate (e.g., hexagonal boron nitride)
  • graphene silicone
  • Stacked two-dimensional materials may include a few layers (e.g., about 20 or less) of a single- layer two-dimensional material or various combinations of single-layer two-dimensional materials.
  • the two-dimensional membrane layer 4910 may be a graphene or graphene-based two-dimensional material as a single-layer two-dimensional material or a stacked two-dimensional material.
  • the support substrate layer 4920 may include any appropriate planar-type substrate.
  • the support substrate layer 4920 may be made from ceramic porous materials, such as silica, silicon, silicon nitride, and combinations thereof.
  • he support substrate layer 4920 may be made from a polymer material, such as track-etched polymers, expanded polymers, patterned polymers, non-woven polymers, and combinations thereof.
  • the support substrate layer 4920 may include a polymer selected from the group consisting of polysulfones, polyurethane, polymethylmethacrylate (PMMA), polyethylene glycol (PEG), polylactic-co-glycolic acid (PLGA), PLA, PGA, polyamides (such as nylon-6,6, supramid and nylamid), polyimides, polypropylene, polyethersulfones (PES), polyvinylidine fluoride (PVDF), cellulose acetate, polyethylene, polypropylene, polycarbonate,
  • the support substrate layer 4920 may be a track- etched polycarbonate (TEPC) membrane.
  • TEPC track- etched polycarbonate
  • the support substrate layer 4920 may be a membrane formed by silicon nitride, track-etched polyimide, track-etched polyester, track-etched SiN, nanoporous silicon, nanoporous silicon nitride, an electrospun membrane, and/or a PVDF membrane.
  • the substrate passages 4925 may be formed randomly or in a patterned manner.
  • pores 4915 overlap with the substrate passages 4925.
  • a first portion of pores 4915a overlap with, or are in fluid communication with, the support substrate passages 4925.
  • the first portion of pores 4915a contributes to overall pore utilization because they allow fluid to flow through to the substrate passages 4925.
  • a second portion of pores 4915b do not overlap with, or fail to be in fluid communication with, the support substrate passages 4925.
  • the second portion of pores 4915b does not contribute to overall pore utilization because fluid cannot flow from these pores into the support substrate passages 4925.
  • a support substrate passage 4925a may fail to be in fluid communication with any of the pores 4915.
  • this blocked support substrate passageg 4925a receives no fluid flow, thereby decreasing the overall utilization of the support substrate passages 4925.
  • FIG. 50 illustrates a perspective view of the two-dimensional membrane layered structure 4900 having a plurality of flow passages 4955 disposed between the two-dimensional membrane layer 4910 and the support substrate layer 4920.
  • the flow passages 4955 provide a means for the second portion of pores 4915b to be utilized by providing a flow path for fluid to flow from a respective pore 4915b to a nearby substrate passage 4925.
  • the flow passages 4955 may also provide a flow path from the second portion of pores 4915b to the blocked support substrate passage 4925a such that fluid may flow through the blocked support substrate passage 4925a.
  • the integration of the flow passages 4955 provide for an increase in the overall pore utilization of the two-dimensional membrane layer 4910 and a means for increased fluid flow through the support substrate layer 4920.
  • FIG. 51 shows a cross-sectional view of the two-dimensional membrane layered structure 4900 having flow passages 4955 formed therein in accordance with a first embodiment.
  • a plurality of interlayer supports 4950 may be disposed laterally on an upper surface 4926 of the support substrate layer 4920.
  • the two-dimensional membrane layer 4910 is then disposed onto the upper surface 4926 of the support substrate layer 4920 having the interlayer supports 4950 disposed thereon.
  • the interlayer supports 4950 support the two-dimensional membrane layer 4910 while pushing the two-dimensional membrane layer 4910 upward from the support substrate layer 4920 to form the flow passages 4955 that allow fluid to flow through the pores 4915b.
  • the interlayer supports 4950 may take numerous forms.
  • the interlayer supports 4950 may be carbon nanotubes.
  • FIGS. 53 and 54 show interlayer supports in the form of carbon nanotubes spray-coated onto an upper surface of a support substrate layer in the form of a track-etched polyimide layer before the two- dimensional membrane layer is disposed onto the support substrate layer.
  • the carbon nanotubes are disposed onto the upper surface of the support substrate layer so as to extend laterally across the upper surface to provide access for fluid flow to the substrate passages.
  • the carbon nanotubes may be single-walled or multi-walled.
  • the interlayer supports 4950 may be electrospun fibers.
  • the interlayer supports 4950 may be nanorods, nanoparticles, (e.g., oxide nanoparticles, octadecyltrichlorosilane nanoparticles), fullerenes, collagen, keratin, aromatic amino acids, polyethylene glycol, lithium niobate particles,, decorated nano-dots, nanowires, nanostrands, lacey carbon material, proteins polymers (e.g., hygroscopic polymer, thin polymer, amorphous polymer), hydrogels, self-assembled monolayers, allotropes, nanocrystals of 4- dimethylamino-N-methyl-4-stilbazolium tosylate, crystalline polytetrafluoroethylene, or combinations thereof.
  • nanoparticles e.g., oxide nanoparticles, octadecyltrichlorosilane nanoparticles
  • fullerenes
  • the density of the interlayer supports 4950 may comprise about 5% to about 50% of the total area of the upper surface 4926 of the substrate support layer 4920 to provide a sufficient pore utilization increase to the composite 4900, while at the same time minimizing a decrease in mechanical support of the two-dimensional membrane layer 4910. In some embodiments, the density of the interlayer supports 4950 comprises 40 to 45 % of the total area of the upper surface 4926 of the support substrate layer 4920.
  • the interlayer supports 4950 may be applied to the upper surface 4926 of the support substrate layer 4920 in any appropriate manner.
  • the interlayer supports 4950 may be carbon nanotubes that may be spray-coated in random orientations onto the upper surface 4926 of the support substrate layer 4920.
  • the spray-coating may be controlled such that the density of the carbon nanotubes applied to the upper surface 4926 may be fine-tuned.
  • Other methods of disposing the interlayer supports 4950 onto the upper surface 4926 of the support substrate layer 4920 may include, but are not limited to, electrostatic deposition, drop casting, spin-coating, sputtering, lithography, ion beam induced deposition, atomic layer deposition, or electron beam induced deposition.
  • Additional methods include the application of electrospun fibers by an electric field, the acceleration of nanoparticles by a potential, or the use of an ion beam to irradiate material present on the upper surface 4926 to form raised structures on the upper surface 4926 of the support substrate layer 4920.
  • FIG. 52 shows a cross-sectional view of the two-dimensional membrane layered structure 4900 having flow passages 4955 formed therein in accordance with a second embodiment.
  • a plurality of grooves 4950' are laterally formed onto the upper surface 4926 of the support substrate layer 4920 to form the flow channels 4955.
  • fluid may flow through the pores 4915b to the support substrate channels 4925, thereby increasing the overall pore utilization of the two-dimensional membrane layer 4910.
  • the plurality of grooves 4950' may be formed into the upper surface 4926 of the support substrate layer 4925 by any appropriate means.
  • the grooves 4950' may be formed by etching the upper surface 4926.
  • the grooves 4950' may be formed by focused ion beam milling, lithography methods (e.g., optical, electron beam lithography, extreme UV lithography) on resists followed by suitable etching (e.g., reactive ion etching), block copolymer mask focused on columnar and aligned structures followed by suitable etching, laser ablation, nanoimprint, scanning probe lithography, shadowmask deposition followed by suitable etching, or sparse aperture masking methods.
  • lithography methods e.g., optical, electron beam lithography, extreme UV lithography
  • suitable etching e.g., reactive ion etching
  • block copolymer mask focused on columnar and aligned structures followed by suitable etching laser ablation, nanoimprint, scanning probe lith
  • the grooves 4950' may be formed in a regular, structured pattern, such as a lattice-like pattern, or in a random pattern.
  • the grooves 4950' may be formed to have a depth and a width of about 1 nm to about 5 ⁇ . In some embodiments, the depth and width may range from about 10 nm to about 1000 nm. In other embodiments, the depth and width of the grooves 4950' may range from about 50 nm to about 250 nm. In certain embodiments, the density of the grooves 4950' may comprise up to 50 to 75 % of the total area of the upper surface 4926 of the support substrate layer 4920.
  • the flow passages may be formed by interlayer supports disposed on an upper surface of the support substrate layer.
  • the flow passages may be formed by grooves provided on the upper surface of the support substrate layer.
  • the flow passages may be formed both by interlayer supports disposed on the upper surface of the support substrate layer and grooves provided on the upper surface of the support substrate layer.
  • the fluid flow passages may be formed between the two-dimensional support layer and the support substrate layer such that an increase in the amount of pores that allow fluid to flow to passages in the support substrate layer may be realized.
  • the flow passages may result in an increase in overall pore utilization in the layered structure without resulting in a loss of mechanical support provided to the two-dimensional membrane.
  • the two-dimensional membrane layered structures described herein have broad application, including in water filtration, immune-isolation, (i.e., protecting substances from an immune reaction), timed drug release (e.g., sustained or delayed release), hemodialysis, and hemofiltration.
  • Some embodiments described herein comprise a method of water filtration, water desalination, water purification, immune-isolation, timed drug release, hemodialysis, or hemofiltration, where the method comprises exposing a two-dimensional membrane layered structure to an environmental stimulus, and wherein the two-dimensional membrane layered structure comprises a two-dimensional membrane layer having a plurality of pores (e.g., a porous graphene-based material) and a support substrate layer having a plurality of substrate passages.
  • a method of water filtration, water desalination, water purification, immune-isolation, timed drug release, hemodialysis, or hemofiltration where the method comprises exposing a two-dimensional membrane layered structure to an environmental stimulus, and wherein the two
  • Some embodiments include methods of filtering water comprising passing water through a two-dimensional membrane layered structure. Some embodiments include
  • desalinating or purifying water comprising passing water through a two-dimensional membrane layered structure.
  • the water can be passed through the two-dimensional membrane layered structure by any known means, such as by diffusion or gravity filtration, or with applied pressure (e.g., applied with a pump or via osmotic pressure).
  • Some embodiments include methods of selectively separating or isolating substances in a biological environment, wherein the two-dimensional membrane layered structure separates or isolates biological substances based on characteristics of the substance, such as size. Such methods can be useful in the context of disease treatment, such as in the treatment of diabetes.
  • biological substances below a certain size threshold can migrate across the two-dimensional membrane layered structure.
  • even biological substances below the size threshold are excluded from migrating across the two-dimensional membrane layered structure due to functionalization of the plurality of pores, the plurality of substrate passages, the plurality of interlayer supports and/or the plurality of grooves.
  • the plurality of pores, or at least a portion thereof is functionalized.
  • the plurality of substrate passages, or at least a portion thereof is functionalized, for instance by attaching or embedding a functional group.
  • the plurality of interlayer supports and/or the plurality of grooves, or at least a portion thereof is functionalized, for instance by attaching or embedding a functional group.
  • the functionalization moieties are trapped between two layers, but are not restricted to a single position in the flow passages (i.e., they are mobile within the flow passages, but are inhibited from traversing the layers, e.g., based the size of the pores in the two- dimensional membrane layer).
  • functionalization comprises surface charges (e.g., sulfonates) attached to the pores, substrate passages, interlayer supports, and/or grooves. Without being bound by theory, it is believed that surface charges can impact which molecules and/or ions can traverse the two-dimensional membrane layered structure.
  • functionalization comprises specific binding sites attached to the pores, substrate passages, interlayer supports, and/or grooves.
  • functionalization comprises proteins or peptides attached to the pores, substrate passages, interlayer supports, and/or grooves.
  • functionalization comprises antibodies and/or antigens (e.g., IgG-binding antigens) attached to the pores, substrate passages, interlayer supports, and/or grooves.
  • functionalization comprises adsorptive substances attached to the pores, substrate passages, interlayer supports, and/or grooves.
  • functionalization involves catalytic and/or regenerative substances or groups.
  • functionalization comprises a negatively or partially negatively charged group (e.g., oxygen) attached to the pores, substrate passages, interlayer supports, and/or grooves.
  • functionalization comprises a positively or partially positively charged group attached to the pores, substrate passages, interlayer supports, and/or grooves.
  • functionalizing the pores, substrate passages, interlayer supports, and/or grooves functions to: restrict contaminants from traversing the two-dimensional membrane layered structure; act as a disposable filter, capture, or diagnostic tool; increase biocompatibility (e.g., when polyethylene glycol is used for functionalization); increase filtration efficiency; position the interlayer supports (e.g., interlayer supports can be positioned near the pores via affinity -based functionalization in the pores; additional spacers can be positioned in interlaminar areas); increase selectivity at or near the pores or in asymmetric two-dimensional membrane layered structure; and/or protect interlayer supports (e.g., from the external environment or from a particular vulnerability such as degradation).
  • biocompatibility e.g., when polyethylene glycol is used for functionalization
  • increase filtration efficiency position the interlayer supports (e.g., interlayer supports can be positioned near the pores via affinity -based functionalization in the pores; additional spacers can be positioned in interlaminar areas); increase selectivity at or near the pores or
  • Some embodiments include membranes, and methods of making membranes, with tunable selectivity, e.g., where the membrane can adapt to environmental conditions.
  • the membrane can be tuned as a result of being adjusted to alter selectivity.
  • Some other embodiments include methods of altering membrane permeability and methods of using membranes with tunable selectivity.
  • Membranes of some embodiments are formed with multiple layers of porous graphene-based material, where the layers are positioned or stacked such that a space between the layers can function as a channel or conduit.
  • the membrane comprises at least two layers of porous graphene-based material, such as from about 2 to about 10 layers, or from about 2 to about 5 layers of porous graphene-based material.
  • the membrane comprises 2, 3, 4, 5, 6, 7, 8, 9, or 10 layers of porous graphene-based material.
  • the number of channels in the membrane depends in part on the number of graphene-based material layers in the membrane. Thus, two graphene-based material layers can form one channel; three graphene-based material layers can form two channels.
  • the walls of the channel comprise the graphene-based material layers.
  • a graphene-based material layer comprises a single sheet of graphene-based material.
  • a graphene-based material layer comprises multiple sheets of graphene-based material, such as from about 2 to about 5 sheets of graphene-based material.
  • the sheets of can be combined in the layer via, e.g., covalent bonding and/or van der Waals forces.
  • Graphene-based materials are discussed in greater detail later in this application.
  • the porous graphene-based material layers in the membrane can be structurally similar, structurally identical, or structurally different from other porous graphene-based material layers in the membrane.
  • all graphene-based material layers have the same number of graphene sheets.
  • the number of graphene sheets in a layer is different from the number of graphene sheets in a different layer.
  • the porous graphene-based material layers in the membrane can be chemically similar, chemically identical, or chemically different from other porous graphene-based material layers in the membrane.
  • graphene-based material layers can be functionalized with similar, identical, or different functional groups from other graphene-based material layers.
  • the thickness of the membrane depends in part on the number of layers present in the membrane and/or on the number of graphene-based material sheets in the membrane.
  • the membrane is at least 5 nm thick, such as from about 5 nm to about 250 nm thick, from about 5 to about 20 nm thick, or from about 20 to about 50 nm thick.
  • Membranes of some of the embodiments provide a means for increasing and/or decreasing the diameter of the channel.
  • at least one spacer substance can be positioned in the channel between the graphene-based material layers.
  • the spacer substance is responsive to an environmental stimulus.
  • environmental stimuli include changes in temperature, pressure, pH, ionic concentration, solute concentration, tonicity, light, voltage, electric fields, magnetic fields, pi-bonding availability, and combinations thereof.
  • the spacer substance is responsive to a single environmental stimulus.
  • the spacer substance is responsive to two or more
  • the properties of the responsive spacer substances can be altered upon exposure to an environmental stimulus.
  • the spacer substance can expand and/or contract in response to an environmental stimulus.
  • the effective diameter of the spacer substance can be reduced in response to an increase in applied pressure.
  • Figures 60-62 shows a membrane channel with altered selectivity following application of pressure (initially, both water and ions, electrolytes, and/or salts in solution can traverse the membrane - Figure 60; increased pressure compresses the spacer substance and prevents the salt from traversing the membrane - Figure 61;
  • Figure 62 demonstrates that pressure can be used to compress a spacer substance in a membrane with three graphene layers).
  • the term "effective diameter" as it relates to spacer substances refers to the distance between two points on the spacer substance, where the points interact with different graphene-based material layers that form a channel of the membrane (i.e., the height of the spacer substance in the membrane). In this way, the effective diameter of the spacer substance influences the diameter of the channel.
  • An initial effective diameter of the spacer substances can be determined prior to incorporating the spacer substance into the membrane, for instance via transmission electron microscopy (TEM) tomography.
  • TEM transmission electron microscopy
  • the effective diameter can be determined via scanning electron microscopy (SEM).
  • the effective diameter of the spacer substance can be increased upon removal of or reduction in applied pressure. In some embodiments, the effective diameter of the spacer substance increases upon hydration and/or decreases upon dehydration. In some embodiments, the spacer substance is capable of undergoing a physical and/or chemical transformation in the membrane based on an interaction with an activating substance, such as an affinity-based interaction or a chemical reduction. In some embodiments, the environmental stimulus induces a conformational change in the spacer substance that alters the effective diameter of the spacer substance.
  • conformational changes between trans and cis forms of a spacer substance can alter the effective diameter of the spacer substance (by way of example, a spacer substance could be a polymer with an embedded diazo dye, where exposure to the appropriately colored light alters the volume of the dye based on cis-/trans- conformational changes).
  • the spacer substance undergoes a physical and/or chemical transformation that is pH-modulated or optically modulated.
  • the environmental stimulus degrades the spacer substance to alter the effective diameter of the spacer substance.
  • the effective diameter of the spacer substance can be altered by applying a voltage to the membrane or via electrowetting. See, for instance, Figure 63, showing that the spacing between layers can be altered via voltage-sensitive spacer substances.
  • a voltage or field source is applied across the membrane.
  • the voltage assists in moving the permeant across the membrane.
  • the voltage is applied across the membrane using a power source, such as a battery, a wall outlet, or an applied RF field (or other beam).
  • a voltage of about 1 mV to about 900 mV is applied across the membrane.
  • the voltage is applied to a graphene-based material layer in-plane.
  • the graphene can be biased, for instance with the use of an insulating material.
  • the voltage applied across the membrane is low enough that the graphene does not delaminate and/or low enough that the voltage does not induce electrolysis.
  • the responsive change in spacer substance properties can be reversible or
  • the spacer substances reversibly expands and/or reversibly contracts in response to the environmental stimulus. Therefore, in some embodiments, the size of the spacer substance can be repeatedly increased and then decreased in succession. In some embodiments, the size of spacer substance can be increased or decreased, but not both. In some embodiments, the size of the spacer substance can be increased or decreased irreversibly.
  • Spacer substances can include polymers, fibers, hydrogels, molecules, nanostructures, nanoparticles, self-assembled monolayers, and allotropes that are responsive to an environmental stimulus.
  • the spacer substance is a smart polymer, such as a hygroscopic polymer; a thin polymer that expands when hydrated; or an amorphous polymer, such as a porous amorphous polymer.
  • the spacer substance comprises electrospun fibers that can be swelled upon exposure to a solvent.
  • the spacer substance comprises materials with a high thermal expansion coefficient, which expand or contract in response to a temperature stimulus.
  • the spacer substance is deliquescent.
  • the spacers are substantially inert. In some embodiments, the spacers are not inert (i.e., they can be reactive).
  • Exemplary spacer substance includes particle substances such as metal nanoparticles (e.g., silver nanoparticles), oxide nanoparticles, octadecyltrichlorosilane nanoparticles, carbon nanotubes, and fullerenes.
  • the spacer substance includes nanorods, nano- dots (including decorated nano-dots), nanowires, nanostrands, and lacey carbon materials.
  • Exemplary spacer substances also include structural proteins, collagen, keratin, aromatic amino acids, and polyethylene glycol. Such spacer substances can be responsive to changes in tonicity of the environment surrounding the spacer substance, pi-bonding availability, and/or other environmental stimuli.
  • the spacer substance is a piezoelectric, electrostrictive, or ferroelectric magnetic particle.
  • the magnetic particle comprises a molecular crystal with a dipole associated with the unit cell.
  • the magnetic particles can be oriented based on an external magnetic field.
  • Exemplary magnetic particles include lithium niobate, nanocrystals of 4-dimethylamino-N-methyl-4-stilbazolium tosylate (DAST)), crystalline polytetrafluoroethylene (PTFE), electrospun PTFE, and combinations thereof.
  • the spacer substance heats up faster or slower than its surroundings. Without being bound by theory, it is believed that such embodiments will allow the rate of passage of permeants, or a subset of permeants, across the membrane to be increased and/or decreased.
  • spacer substances respond to electrochemical stimuli.
  • a spacer substance can be an electrochemical material (e.g., lithium ferrophosphate), where a change in oxidation state of the spacer substance (e.g., from 2- to 3-) alters permeability of the membrane.
  • changing the oxidation state of the spacer substances alters the interaction between the spacer substance and potential permeants.
  • the change in oxidation state results from a redox-type reaction. In some embodiments, the change in oxidation state results from a voltage applied to the membrane.
  • the spacer substance comprises contamination structures formed by utilizing a focused ion beam, e.g., to modify heavy levels of contamination on graphene-based material into more rigid structures. For instance, in some embodiments, mobilization and migration of contamination on the surface of the graphene-based material occurs - coupled in some embodiments with some slight beam induced deposition - followed by modification and induced bonding where the beam is applied. In some embodiments, combining contamination structures allows the geometry, thickness, rigidity, and composition of the spacer substance to be tuned to respond to an environmental stimulus (e.g., pressure). Exemplary contamination-based spacer substances are shown in Figures 64A-D.
  • spacer substances have an affinity for graphene. In some embodiments, spacer substances have a higher affinity for graphene than for substances or solutions that can permeate the membrane.
  • the spacer substance is chemically modified to have a functional group or a desired physiochemical property.
  • the spacer substance is modified to be hydrophobic.
  • the spacer substance is modified to be hydrophilic.
  • the spacer substance is modified by addition of hydroxyl groups.
  • the spacer substance is attached to antibody receptors.
  • the spacer substance is attached to proteins, enzymes, and/or catalysts.
  • a metallic, organometallic, and/or zeolite-based functional group can act as a catalyst for precursors that enter the membrane.
  • spacer substances are functionalized to preferentially orient a permeant (e.g., water or a solvent).
  • a permeant that is in the preferential orientation can traverses the membrane in that preferential orientation, whereas a permeant that is not the preferential orientation does not.
  • membranes include a plurality of a single type of spacer substance (e.g., a plurality of nanoparticles). In some embodiments, membranes include a multiple types of spacer substances (e.g., nanoparticles and polymers). In some embodiments, the spacer substance is a porous layer, such as a porous amorphous polymer layer. In some embodiments, the spacer substance is a self-assembled co-polymer that leaves channels between graphene-based material layers (e.g., the channels can be a sub-nm in diameter to about 40 nm in diameter).
  • the spacer substance or substances between two graphene- based material layers can be the same as or different from the spacer substance or substances between two other graphene-based material layers. That is, the spacer substance or substances in one membrane channel can be the same as or different from the spacer substance or substances in a different membrane channel.
  • the diameter of the channel can be tailored based on the density and/or size of the spacer substance incorporated into the membrane. For instance, without being bound by theory, an increase in spacer substance density is believed to be associated with an increase in channel diameter as compared to a channel comprising the same spacer substance, but at a lower density. Indeed, an increased distance between spacer substances (i.e., a low density) allows flexible graphene-based material layers to attain stable configurations in which portions of different layers are in close proximity, thereby lowering the diameter of the channel.
  • the spacer substances are incorporated at a sufficiently low density to allow inter-layer interactions (e.g., interactions between graphene in different layers).
  • the spacer substances are incorporated at a sufficiently high density to allow chemical interactions (e.g., covalent or van der Waals interactions) between the layers and the spacer substances, but to prevent inter-layer chemical interactions.
  • both layer-spacer substance and inter-layer chemical interactions are present in the membrane.
  • the spacer substances are positioned in the channel with an average distance between spacer substances of from 10 nm to about 150 nm.
  • the spacer density is such that spacer substances cover up to about 50% of the surface area of center of the channel - i.e., in a 2D-plane along the center of the channel, spacer substances cover up to about 50% of the area of that plane.
  • the spacer density is such that the spacer substances cover up to about 40%, up to about 30%, up to about 20%), or up to about 10%> of the surface area of the center of the channel. Spacer density can be calculated, for instance, based on the amount of spacer substance used, the dimensions of the membrane, and the dimensions of the spacer.
  • the size of the spacer substances can also impact properties of the membrane.
  • spacer substances with a relatively large effective diameter can be used to prepare channels with a relatively high maximum diameter.
  • maximum diameter as it relates to channel width is defined by the diameter of the channel at a point of interaction between a layer and the spacer substance in the channel with the largest effective diameter.
  • the diameter of a channel at any given location can be higher or lower than the maximum diameter.
  • spacer substances with relatively small effective diameter can be used to prepare channels with a relatively low maximum diameter.
  • the spacer substances have an effective diameter of from about 0.3 nm to about 100 nm, such from about 0.3 nm to about 0.5 nm, from about 0.5 nm to about 2 nm, or from about 20 nm to about 50 nm.
  • the spacer substance is restricted from traversing the graphene-based material layers.
  • the spacer substance is larger than the size of the pores in the graphene-based material layers, or larger than a portion of the pores in the graphene-based material layers.
  • the spacer substance is larger in one dimension than the size of the pores, or a portion thereof, in the graphene-based material layers.
  • the spacer substance interacts with the graphene-based material layer (e.g., via covalent bonding or van der Waals interactions).
  • the interactions between the spacer substance and the graphene-based material layer is stronger than an interaction between the spacer substance and permeants that pass through the membrane.
  • the effective diameter of the spacer substance can be tunable, i.e., it can be altered upon exposure to an environmental stimulus.
  • the effective diameter of spacer substances can be altered, upon exposure to an environmental stimulus, by about 0.3 nm to about 50 nm, such as from about 0.3 nm to about 0.5 nm, from about 0.5 nm to about 2 nm, from about 10 nm to about 20 nm, or from about 20 nm to about 50 nm.
  • the effective diameter of the spacer substance can be reduced by about 0.3 nm to about 50 nm, such as from about 0.3 nm to about 0.5 nm, from about 0.5 nm to about 2 nm, from about 10 nm to about 20 nm, or from about 20 nm to about 50 nm. In some embodiments, the effective diameter of the spacer substance can be increased by about 0.3 nm to about 50 nm, such as from about 0.3 nm to about 0.5 nm, from about 0.5 nm to about 2 nm, from about 10 nm to about 20 nm, or from about 20 nm to about 50 nm.
  • the membrane comprises one or more channels that are impermeable (i.e., the channel diameter is about 0, and the channel is referred to as being in a closed position) before and/or after exposure to an environmental stimulus.
  • the channel diameter is about 0, and the channel is referred to as being in a closed position
  • the diameter of the channel is from about 0.3 nm to about 100 nm, such from about 0.3 nm to about 0.5 nm, from about 0.5 nm to about 2 nm, or from about 20 nm to about 50 nm.
  • the channel diameter is about 0.5 nm, about 1 nm, about 2 nm, about 5 nm, about 10 nm, about 15, nm, about 20 nm, about 25 nm, about 30 nm, about 35 nm, about 40 nm, about 45 nm, or about 50 nm.
  • the channel diameter is smaller than the diameter of pores, or a portion of pores, in the graphene-based material layers.
  • channel diameter and "diameter of the channel” are defined by the diameter of substances that can traverse the membrane. For example, substances with a diameter of more than 10 nm are inhibited from traversing a membrane with a channel diameter of 10 nm or less; substances with a diameter of 50 nm or more are inhibited from traversing a membrane with a channel diameter of 50 nm or less. Channel diameter can be assessed, for example, using a flow test to determine the size cutoff for substances that can traverse the membrane. In some embodiments, particles smaller than the diameter of the channel are also inhibited from traversing the channel, for instance due to interactions with the graphene-based material layer or due to a solvation shell around the particle.
  • the channel diameter can be the larger than, about the same as, or smaller than the diameter of pores on the graphene-based material layer. In some embodiments, the channel diameter is smaller than the average diameter of pores in the graphene-based material layer, such as about 5% smaller, about 10% smaller, about 20% smaller, or about 50% smaller. In some embodiments, the channel diameter is about the same as the average diameter of pores in the graphene-based material layer. In some embodiments, the channel diameter is larger than the average diameter of pores in the graphene-based material layer, and the channel is
  • the channel diameter can be estimated based on the diameter of the spacer substances.
  • the channel diameter is tunable, i.e., it can be altered upon exposure to an environmental stimulus, by from about 0.3 nm to about 50 nm, such as from about 0.3 nm to about 0.5 nm, from about 0.5 nm to about 2 nm, or from about 20 nm to about 50 nm.
  • the channel diameter can be reduced by about 0.3 nm to about 50 nm, such as from about 0.3 nm to about 0.5 nm, from about 0.5 nm to about 2 nm, or from about 20 nm to about 50 nm.
  • the channel diameter can be increased by about 0.3 nm to about 50 nm, such as from about 0.3 nm to about 0.5 nm, from about 0.5 nm to about 2 nm, or from about 20 nm to about 50 nm.
  • permeability and/or selectivity of the membrane e.g., as measured by a flow test
  • membranes of some of the embodiments are responsive to one or more environmental stimuli. For instance, channels located between membrane layers can be increased or decreased in diameter as a result of changes in the size of the spacer substances.
  • a membrane that allows passage of water but excludes salt ions e.g.
  • Na+ and C1- can be tuned to allow passage of both water and salt ions.
  • the membrane can be tuned to allow passage of biological compounds such as insulin, proteins and/or other biological material (e.g., RNA, DNA, and/or nucleic acids), but to exclude passage of other larger biological compounds such as antibodies.
  • the membrane can be tuned to be permeable to oxygen and nutrients, but to exclude passage of cells (such as immune cells), viruses, bacteria, antibodies, and/or complements of the immune system.
  • the membrane can be tuned from one that allows passage of antibodies to one that inhibits passage of antibodies.
  • Tunable membranes have broad application, including in water filtration, immune- isolation (i.e., protecting substances from an immune reaction), timed drug release (e.g., sustained or delayed release), hemodialysis, and hemofiltration.
  • Some embodiments described herein comprise a method of water filtration, water desalination, water purification, immune- isolation, timed drug release, hemodialysis, or hemofiltration, where the method comprises exposing a membrane to an environmental stimulus, and wherein the membrane comprises a first layer with a porous graphene-based material and a second layer with a porous graphene-based material.
  • Some embodiments include methods of filtering water comprising passing water through a membrane. Some embodiments include desalinating or purifying water comprising passing water through a membrane.
  • the water can be passed through the membrane by any known means, such as by diffusion or gravity filtration, or with applied pressure (e.g. applied with a pump or via osmotic pressure).
  • Some embodiments include methods of selectively separating or isolating substances in a biological environment, wherein the membrane separates or isolates biological substances based on characteristics of the substance, such as size. Such methods can be useful in the context of disease treatment, such as in the treatment of diabetes.
  • biological substances below a certain size threshold can migrate across the membrane.
  • even biological substances below the size threshold are excluded from migrating across the membrane due to functionalization of membrane pores and/or channels.
  • the pores, or at least a portion thereof are functionalized.
  • the channels, or at least a portion thereof are functionalized, for instance by attaching or embedding a functional group.
  • the functionalization moieties are trapped between two graphene-based material layers, but are not restricted to a single position in the channel (i.e., they are mobile within the channel, but are inhibited from traversing the two-dimensional material layers, e.g., based the size of the pores in the graphene-based material layers).
  • functionalization comprises surface charges (e.g., sulfonates) attached to the pores and/or channels.
  • functionalization comprises specific binding sites attached to the pores and/or channels.
  • functionalization comprises proteins or peptides attached to the pores and/or the channel.
  • functionalization comprises antibodies and/or antigens (e.g., IgG-binding antigens) attached to the pores and/or channels.
  • functionalization comprises adsorptive substances attached to the pores and/or channels.
  • functionalization involves catalytic and/or regenerative substances or groups.
  • functionalization comprises a negatively or partially negatively charged group (e.g., oxygen) attached to the pores and/or channels.
  • functionalization comprises a positively or partially positively charged group attached to the pores and/or channels.
  • functionalizing the pores and/or channels functions to: restrict contaminants from traversing the membrane; act as a disposable filter, capture, or diagnostic tool; increase biocompatibility (e.g., when polyethylene glycol is used for functionalization); increase filtration efficiency; position the spacer substances in the channels (e.g., spacers can be positioned near the pores via affinity -based functionalization in the pores; additional spacers can be positioned in interlaminar areas); increase selectivity at or near the pores or in asymmetric membranes; and/or protect spacer substances (e.g., from the external environment or from a particular vulnerability such as degradation).
  • biocompatibility e.g., when polyethylene glycol is used for functionalization
  • increase filtration efficiency position the spacer substances in the channels (e.g., spacers can be positioned near the pores via affinity -based functionalization in the pores; additional spacers can be positioned in interlaminar areas); increase selectivity at or near the pores or in asymmetric membranes; and/or protect spacer substances (
  • a substrate layer is disposed on one or both surfaces of the membrane. Without being bound by theory, it is believed that the substrate layer can improve biocompatibility of membranes, for instance by reducing biofouling, preventing protein adsorption-related problems, and/or enhancing vascularization. In some embodiments, the substrate layer can increase vascularization and/or tissue ingrowth near the membrane, thus prompting the formation of blood vessels and/or tissue ingrowth in close proximity to the membrane.
  • the substrate layer has a thickness of about 1 mm or less, about 1 ⁇ or less, or about 100 nm or less. In some embodiments, a thickness of the substrate layer can range from about 100 nm to about 100 ?m, or about 1 ⁇ to about 50 ⁇ m, or about 10 ⁇ to about 20 ⁇ m, or about 15 ⁇ to about 25 ⁇ . In some embodiments, the substrate layer has a thickness about 10 ⁇ or greater, or about 15 ⁇ or greater. In some embodiments, the substrate layer has a thickness of less than 1 ⁇ . In some embodiments, the substrate layer has a thickness of about 10 nm to about 100 nm, or about 20 nm to about 50 nm.
  • the enclosure can be supported by one or more support structures.
  • the support structure can itself have a porous structure wherein the pores are larger than those of the two-dimensional material.
  • the support structure is formed as a frame at a perimeter of a two-dimensional material.
  • the support structure is positioned, at least in part, interior to a perimeter of a two- dimensional material.
  • the substrate layer can convey a desired degree of structural support (e.g., to prevent tearing and/or buckling) to the two-dimensional material layer.
  • two or more substrate layers are positioned on the same side of the membrane (e.g., two or more substrate layers can be positioned on the outside of an enclosure comprising the membrane).
  • the substrate is disposed directly on (or affixed directly to) a graphene-based material layer.
  • the substrate is disposed on or affixed to the graphene-based material layer with high conformance (e.g., by disposing a slightly wet substrate on the graphene-based material layer).
  • the substrate is disclosed with low conformance.
  • the substrate is disposed indirectly on (or affixed indirectly to) the graphene-based material; for instance, an intermediate layer can be positioned between the substrate layer and the graphene-based material layer.
  • the substrate layer is disposed or directly or indirectly on (or affixed directly or indirectly to) another substrate layer.
  • the graphene-based material layer is suspended on a substrate layer.
  • the substrate layer is affixed to the graphene-based material layer.
  • the substrate layer can increase vascularization near the membrane, thus prompting the formation of blood vessels and/or tissue ingrowth in close proximity to the membrane.
  • the increased vascularization contributes to decreasing the effective distance between the blood stream and substances being eluted through the membrane.
  • the increased vascularization contributes to viability of substances, such as cells, enclosed within an enclosure comprising the membrane.
  • the substrate layer can be porous and/or nonporous.
  • the substrate layer contains porous and nonporous sections.
  • the substrate layer comprises a porous or permeable fibrous layer.
  • Porous substrates include, for example, one or more of ceramics and thin film polymers. Exemplary ceramics include nanoporous silica (silicon dioxide), silicon, SiN, and combinations thereof.
  • the substrate layer comprises track-etched polymers, expanded polymers, patterned polymers, woven polymers, and/or non-woven polymers.
  • the substrate layer comprises a plurality of polymer filaments.
  • the polymer filaments can comprise a thermopolymer, thermoplastic polymer, or melt polymer, e.g., that can be molded or set in an optional annealing step.
  • the polymer filaments are hydrophobic. In some embodiments, the polymer filaments are hydrophilic.
  • the substrate layer comprises a polymer selected from the group consisting of polysulfones, polyurethane, polymethylmethacrylate (PMMA), polyglycolid acid (PGA), polylactic acid (PLA), polyethylene glycol (PEG), polylactic-co-glycolic acid (PLGA), polyamides (such as nylon-6,6, supramid and nylamid), polyimides, polypropylene, polyethersulfones (PES), polyvinylidine fluoride (PVDF), cellulose acetate, polyethylene, polypropylene, polycarbonate, polytetrafluoroethylene (PTFE) (such as Teflon), polyvinylchloride (PVC), polyether ether ketone (PEEK), mixtures and block co-polymers of any of these, and combinations and/or mixtures thereof.
  • the polymers are biocompatible, bioinert and/or medical grade materials.
  • the substrate layer comprises a biodegradable polymer.
  • a substrate layer forms a shell around an enclosure comprising the membrane (e.g., it completely engulfs the enclosure).
  • the substrate layer shell can be dissolved or degraded, e.g., in vitro.
  • the shell can be loaded with additives, including additives that protect substances inside the enclosure from air or prevent the need for a stabilizing agent.
  • Suitable techniques for depositing or forming a porous or permeable polymer on the graphene-based material layer include casting or depositing a polymer solution onto the graphene-based material layer or intermediate layer using a method such as spin-coating, spray coating, curtain coating, doctor-blading, immersion coating, electrospinning, or other similar techniques. Electrospinning techniques are described, e.g., in US 2009/0020921 and/or U.S. Application No. 14/609,325, both of which are hereby incorporated by reference in their entirety.
  • the process for forming a substrate layer includes an electrospinning process in which a plurality of polymer filaments are laid down to form a porous mat, e.g., on the graphene-based material layer.
  • the mat has pores or voids located between deposited filaments of the fibrous layer.
  • Figure 64 shows an illustrative SEM micrograph of a graphene or graphene-based film deposited upon a plurality of electrospun PVDF fibers.
  • the electrospinning process comprises a melt
  • the polymer can be present in a spin dope at a concentration of 2 wt.% to 15 wt.%, or 5 wt.% to 10 wt.%, or about 7 wt.%.
  • Suitable solvents for the spin dope include any solvent that dissolves the polymer to be deposited and which rapidly evaporates, such as m-cresol, formic acid, dimethyl sulfoxide (DMSO), ethanol, acetone, dimethylacetamide (DMAC), dimethylformamide (DMF), water, and combinations thereof.
  • the spin dope solvent is biocompatible and/or bioinert.
  • the amount of solvent used can influence the morphology of the substrate layer.
  • the spun fibers of the fibrous layer can remain as essentially discrete entities once deposited.
  • wet electrospinning processes deposit the spun fibers such that they are at least partially fused together when deposited.
  • the size and morphology of the deposited fiber mat e.g., degree of porosity, effective pore size, thickness of fibrous layer, gradient porosity
  • the porosity of the fibrous layer can include effective void space values (e.g.
  • a single spinneret can be moved to lay down a mat of the fibrous layer. In some embodiments, multiple spinnerets can be used for this purpose.
  • the spun fibers in an electrospun fibrous layer can have a fiber diameter ranging from about 1 nm to about 100 ⁇ m, or about 10 nm to about 1 ⁇ m, or about 10 nm to about 500 nm, or about 100 nm to about 200 nm, or about 50 nm to about 120 nm, or about 1 ⁇ m to about 5 ⁇ m, or about 1 ⁇ to about 6 ⁇ m, or about 5 ⁇ m to about 10 ⁇ .
  • the fiber diameter is directly correlated with a depth (Z-axis) of a pore abutting the graphene-based material layer (disposed in the X-Y plane), and large diameter fibers can lead to large unsupported spans of material.
  • the substrate layer can have pores (e.g., void spaces) with an effective pore size of from about 1 nm to about 100 ⁇ m, or about 10 nm to about 1 ⁇ m, or about 10 nm to about 500 nm, or about 100 nm to about 200 nm, or about 50 nm to about 120 nm, or about 1 ⁇ to about 5 ⁇ m, or about 1 ⁇ to about 6 ⁇ m, or about 5 ⁇ to about 10 ⁇ .
  • Pore diameters in the substrate layer can be measured, for example, via porometry methods (e.g., capillary flow porometry) or extrapolated via imagery.
  • the substrate layer can have an average pore size gradient throughout its thickness.
  • Pore size gradient describes a layer with a plurality of pores, where the average diameter of the pores increases or decreases based on the proximity of the pore to the graphene-based material layer.
  • a fibrous layer can have an average pore size gradient that decreases nearer the surface of a graphene-based material.
  • an average pore size of the fibrous layer is smaller nearer the surface of the graphene-based material than at an opposite surface of the fibrous layer.
  • the fibrous layer can have effective pore diameters of less than about 200 nm close to the intermediate layer or the graphene-based material layer which can increase to greater than 100 ⁇ at the maximum distance away from the intermediate layer or graphene-based material layer.
  • the fibrous layer can have a "porosity gradient" throughout its thickness, which can be measured for instance using imagery.
  • "Porosity gradient” describes a change, along a dimension of the fibrous layer, in the porosity or total pore volume as a function of distance from the graphene-based material layer.
  • the porosity can change in a regular or irregular manner.
  • a porosity gradient can decrease from one face of the fibrous layer to the other.
  • the lowest porosity in the fibrous layer can be located spatially closest to the graphene-based material layer, and the highest porosity can be located farther away (e.g., spatially closer to an external environment).
  • a porosity gradient of this type can be achieved by electrospinning fibers onto a graphene-based material layer such that a fiber mat is denser near the surface of the graphene- based material layer and less dense further from the surface of the graphene-based material layer.
  • a substrate layer can have a relatively low porosity close to the graphene- based material layer, a higher porosity at a mid-point of the fibrous layer thickness (which can, for example, contain a supporting mesh for reinforcement or other particles), and return to a relatively low porosity at an external surface distal to the graphene-based material layer.
  • the substrate layer can have a "permeability gradient" throughout its thickness.
  • Permeability gradient describes a change, along a dimension of the fibrous layer, in the "permeability” or rate of flow of a liquid or gas through a porous material.
  • the permeability can change in a regular or irregular manner.
  • a permeability gradient can decrease from one face of the fibrous layer to the other.
  • the lowest permeability in the fibrous layer can be located spatially closest to the graphene-based material layer, and the highest permeability can be located farther away.
  • permeability of a layer can increase or decrease without pore diameter or porosity changing, e.g., in response to chemical functionalization, applied pressure, voltage, or other factors.
  • both the graphene-based material layer and the substrate layer include a plurality of pores therein.
  • both the graphene-based material layer and the substrate layer contain pores, and the pores in the graphene-based material layer are smaller, on average, than the pores in the substrate layer.
  • the median pore size in the graphene-based material layer is smaller than the median pore size in the substrate layer.
  • the substrate layer can contain pores with an average and/or median diameter of about 1 ⁇ or larger and the graphene-based material layer can contain pores with an average and/or median diameter of about 10 nm or smaller.
  • the average and/or median diameter of pores in the graphene-based material layer is at least about 10-fold smaller than the average and/or median diameter of pores in the substrate layer. In some embodiments, the average and/or median diameter of pores in the graphene-based material layer is at least about 100-fold smaller than are the average and/or media diameter of pores in the substrate layer.
  • the substrate layer can provide a scaffold for tissue growth, cell growth and/or vascularization.
  • the substrate layer or wall comprises additives, such as pharmaceuticals, cells, growth factors (e.g., VEGF), signaling molecules, cytokines, clotting factors, blood thinners, immunosuppressants, antimicrobial agents, hormones, antibodies, minerals, nutrients or combinations thereof.
  • additives such as pharmaceuticals, cells, growth factors, clotting factors, blood thinners, immunosuppressants, antimicrobial agents, hormones, antibodies, antigens (e.g., IgG-binding antigens) or an antibody- binding fragment thereof, minerals, nutrients or combinations thereof are positioned on the inside of the disclosure.
  • the substrate layer or membrane comprises materials toxic to bacteria or cells (without being bound by theory, it is believed that incorporating toxic materials into the wall will prevent passage of potentially dangerous or detrimental cells across the membrane).
  • additives beneficially promote cell or tissue viability or growth, reduce or prevent infection, improve vascularization to or near the membrane, improve biocompatibility, reduce biofouling, and/or reduce the risk of adverse reactions.
  • additives can modulate properties, such as hydrophobicity or hydrophilicity, of the substrate layer.
  • additives can be used to modulate elution of a substance from a compartment in the enclosure. For instance, additives can confer shell-like properties to a substrate layer, such that degradation or removal of the additives allows substances to traverse the membrane.
  • an intermediate layer promotes adhesion between the graphene-based material layer and the substrate layer.
  • the enclosure comprises an intermediate layer disposed between the graphene-based material layer and the substrate layer.
  • the enclosure comprises an intermediate layer positioned between two substrate layers on the same side of the graphene-based material layer.
  • the intermediate layer comprises carbon nanotubes, lacey carbon, nanoparticles, lithographically patterned low-dimensional materials, silicon and silicon nitride micromachined material, a fine mesh, such as a transmission electron microscopy grid, or combinations of these.
  • the intermediate layer can be a thin, smooth, porous polymer layer, such as a track etched polymer.
  • the intermediate layer has a thickness of from 3 nm to 10 ⁇ m, 10 nm to 10 ⁇ m, 50 nm to 10 ⁇ m, 100 nm to 10 ⁇ m, 500 nm to 10 ⁇ m, 1 ⁇ m to 10 ⁇ m, or 2 ⁇ to 6 ⁇ .
  • membranes of some of the embodiments comprise graphene- based materials.
  • Graphene represents a form of carbon in which the carbon atoms reside within a single atomically thin sheet or a few layered sheets (e.g., about 20 or less) of fused six- membered rings forming an extended sp2-hybridized carbon planar lattice.
  • Graphene-based materials include, but are not limited to, single layer graphene, multilayer graphene or interconnected single or multilayer graphene domains and combinations thereof.
  • graphene-based materials also include materials which have been formed by stacking single or multilayer graphene sheets.
  • multilayer graphene includes 2 to 20 layers, 2 to 10 layers or 2 to 5 layers.
  • layers of multilayered graphene are stacked, but are less ordered in the z direction (perpendicular to the basal plane) than a thin graphite crystal.
  • a sheet of graphene-based material may be a sheet of single or multilayer graphene or a sheet comprising a plurality of interconnected single or multilayer graphene domains, which may be observed in any known manner such as using for example small angle electron diffraction, transmission electron microscopy, etc..
  • the multilayer graphene domains have 2 to 5 layers or 2 to 10 layers.
  • a domain refers to a region of a material where atoms are substantially uniformly ordered into a crystal lattice. A domain is uniform within its boundaries, but may be different from a neighboring region. For example, a single crystalline material has a single domain of ordered atoms.
  • At least some of the graphene domains are nanocrystals, having domain size from 1 to 100 nm or 10-100 nm. In some embodiments, at least some of the graphene domains have a domain size greater than from 100 nm to 1 cm, or from 100 nm to 1 micron, or from 200 nm to 800 nm, or from 300 nm to 500 nm. In some embodiments, a domain of multilayer graphene may overlap a neighboring domain. Grain boundaries formed by crystallographic defects at edges of each domain may differentiate between neighboring crystal lattices.
  • a first crystal lattice may be rotated relative to a second crystal lattice, by rotation about an axis perpendicular to the plane of a sheet, such that the two lattices differ in crystal lattice orientation.
  • the sheet of graphene-based material is a sheet of single or multilayer graphene or a combination thereof.
  • the sheet of graphene-based material is a sheet comprising a plurality of interconnected single or multilayer graphene domains.
  • the interconnected domains are covalently bonded together to form the sheet.
  • the sheet is polycrystalline.
  • the thickness of the sheet of graphene-based material is from 0.3 to 10 nm, 0.34 to 10 nm, from 0.34 to 5 nm, or from 0.34 to 3 nm. In some embodiments, the thickness includes both single layer graphene and the non-graphenic carbon.
  • a sheet of graphene-based material comprises intrinsic or native defects.
  • Intrinsic or native defects may result from preparation of the graphene-based material in contrast to perforations which are selectively introduced into a sheet of graphene- based material or a sheet of graphene.
  • Such intrinsic or native defects may include, but are not limited to, lattice anomalies, pores, tears, cracks or wrinkles.
  • Lattice anomalies can include, but are not limited to, carbon rings with other than 6 members (e.g. 5, 7 or 9 membered rings), vacancies, interstitial defects (including incorporation of non-carbon atoms in the lattice), and grain boundaries.
  • Perforations are distinct from openings in the graphene lattice due to intrinsic or native defects or grain boundaries, but testing and characterization of the final membrane such as mean pore size and the like encompasses all openings regardless of origin since they are all present.
  • graphene is the dominant material in a graphene-based material.
  • a graphene-based material may comprise at least 20% graphene, 30% graphene, or at least 40% graphene, or at least 50% graphene, or at least 60% graphene, or at least 70%) graphene, or at least 80% graphene, or at least 90% graphene, or at least 95% graphene.
  • a graphene-based material comprises a range of graphene selected from 30% to 95%, or from 40% to 80% from 50% to 70%, from 60% to 95% or from 75%) to 100%).
  • the amount of graphene in the graphene-based material is quantified as an atomic percentage utilizing known methods including scanning transmission electron microscope examination, or alternatively if STEM or TEM is ineffective another similar measurement technique.
  • a sheet of graphene-based material further comprises non- graphenic carbon-based material located on at least one surface of the sheet of graphene-based material.
  • the sheet is exemplified by two base surfaces (e.g. top and bottom faces of the sheet, opposing faces) and side faces (e.g. the side faces of the sheet).
  • the "bottom" face of the sheet is that face which contacted the substrate during growth of the sheet and the "free" face of the sheet opposite the "bottom” face.
  • non-graphenic carbon-based material may be located on one or both base surfaces of the sheet (e.g. the substrate side of the sheet and/or the free surface of the sheet).
  • the sheet of graphene-based material includes a small amount of one or more other materials on the surface, such as, but not limited to, one or more dust particles or similar contaminants.
  • the amount of non-graphenic carbon-based material is less than the amount of graphene. In some further embodiments, the amount of non-graphenic carbon material is three to five times the amount of graphene; this is measured in terms of mass. In some additional embodiments, the non-graphenic carbon material is characterized by a percentage by mass of said graphene-based material selected from the range of 0% to 80%. In some embodiments, the surface coverage of the sheet of non-graphenic carbon-based material is greater than zero and less than 80%, from 5% to 80%, from 10% to 80%, from 5% to 50% or from 10%) to 50%. This surface coverage may be measured with transmission electron microscopy, which gives a projection.
  • the amount of graphene in the graphene-based material is from 60%> to 95% or from 75% to 100%.
  • the amount of graphene in the graphene-based material is quantified as an atomic percentage utilizing known methods preferentially using transmission electron microscope examination, or alternatively if STEM is ineffective using an atomic force microscope.
  • the non-graphenic carbon-based material does not possess long range order and is classified as amorphous.
  • the non-graphenic carbon-based material further comprises elements other than carbon and/or hydrocarbons.
  • non-carbon elements which may be incorporated in the non-graphenic carbon include hydrogen, oxygen, silicon, copper, and iron.
  • the non-graphenic carbon-based material comprises hydrocarbons.
  • carbon is the dominant material in non-graphenic carbon-based material.
  • a non-graphenic carbon-based material in some embodiments comprises at least 30% carbon, or at least 40% carbon, or at least 50% carbon, or at least 60% carbon, or at least 70% carbon, or at least 80% carbon, or at least 90% carbon, or at least 95% carbon.
  • a non-graphenic carbon-based material comprises a range of carbon selected from 30% to 95%, or from 40% to 80%), or from 50%> to 70%.
  • the amount of carbon in the non-graphenic carbon-based material is quantified as an atomic percentage utilizing known methods preferentially using transmission electron microscope examination, or alternatively if STEM is ineffective using atomic force microscope.
  • Perforation techniques suitable for use in perforating the graphene-based materials may include described herein ion-based perforation methods and UV-oxygen based methods.
  • Ion-based perforation methods include methods in which the graphene-based material is irradiated with a directional source of ions.
  • the ion source is collimated.
  • the ion source is a broad beam or flood source.
  • a broad field or flood ion source can provide an ion flux which is significantly reduced compared to a focused ion beam.
  • the ion source inducing perforation of the graphene or other two- dimensional material is considered to provide a broad ion field, also commonly referred to as an ion flood source.
  • the ion flood source does not include focusing lenses.
  • the ion source is operated at less than atmospheric pressure, such as at 10- 3 to 10 -5 torr or 10 -4 to 10 -6 torr.
  • the environment also contains background amounts (e.g. on the order of 10 -5 torr) of oxygen (02), nitrogen (N2) or carbon dioxide (CO 2 ).
  • the ion beam may be perpendicular to the surface of the layer(s) of the material (incidence angle of 0 degrees) or the incidence angle may be from 0 to 45 degrees, 0 to 20 degrees, 0 to 15 degrees or 0 to 10 degrees.
  • exposure to ions does not include exposure to plasma.
  • UV-oxygen based perforation methods include methods in which the graphene-based material is simultaneously exposed to ultraviolet (UV) light and an oxygen containing gas Ozone may be generated by exposure of an oxygen containing gas such as oxygen or air to the UV light. Ozone may also be supplied by an ozone generator device.
  • the UV-oxygen based perforation method further includes exposure of the graphene-based material to atomic oxygen. Suitable wavelengths of UV light include, but are not limited to wavelengths below 300 nm or from 150 nm to 300 nm. In some embodiments, the intensity from 10 to 100 mW/cm 2 at 6mm distance or 100 to 1000 mW/cm 2 at 6mm distance.
  • suitable light is emitted by mercury discharge lamps (e.g. about 185 nm and 254 nm).
  • UV/oxygen cleaning is performed at room temperature or at a temperature greater than room temperature.
  • UV/oxygen cleaning is performed at atmospheric pressure (e.g. 1 atm) or under vacuum.
  • Perforations are sized as described herein to provide desired selective permeability of a species (atom, molecule, protein, virus, cell, etc.) for a given application.
  • permeability relates to the propensity of a porous material or a perforated two-dimensional material to allow passage (or transport) of one or more species more readily or faster than other species. Selective permeability allows separation of species which exhibit different passage or transport rates. In two-dimensional materials selective permeability correlates to the dimension or size (e.g., diameter) of apertures and the relative effective size of the species. Selective permeability of the perforations in two-dimensional materials such as graphene-based materials can also depend on functionalization of perforations (if any) and the specific species. Separation or passage of two or more species in a mixture includes a change in the ratio(s) (weight or molar ratio) of the two or more species in the mixture during and after passage of the mixture through a perforated two-dimensional material.
  • the characteristic size of the perforation is from 0.3 to 10 nm, from 1 to 10 nm, from 5 to 10 nm, from 5 to 20 nm, from 10 nm to 50 nm, from 50 nm to 100 nm, from 50 nm to 150 nm, from 100 nm to 200 nm, or from 100 nm to 500 nm.
  • the average pore size is within the specified range. In some embodiments, 70% to 99%, 80% to 99%, 85% to 99% or 90 to 99% of the perforations in a sheet or layer fall within a specified range, but other pores fall outside the specified range.
  • Nanomaterials in which pores are intentionally created may be referred to as perforated graphene, perforated graphene-based materials or perforated two-dimensional materials, and the like.
  • Perforated graphene-based materials include materials in which non- carbon atoms have been incorporated at the edges of the pores.
  • Pore features and other material features may be characterized in a variety of manners including in relation to size, area, domains, periodicity, coefficient of variation, etc. For instance, the size of a pore may be assessed through quantitative image analysis utilizing images preferentially obtained through transmission electron microscopy, and if TEM is ineffective, through atomic force microscopy, and if AFM is ineffective, through scanning electron microscopy, as for example presented in Figs.
  • the boundary of the presence and absence of material identifies the contour of a pore.
  • the size of a pore may be determined by shape fitting of an expected species against the imaged pore contour where the size measurement is characterized by smallest dimension unless otherwise specified.
  • the shape may be round or oval.
  • the round shape exhibits a constant and smallest dimension equal to its diameter.
  • the width of an oval is its smallest dimension. The diameter and width measurements of the shape fitting in these instances provide the size measurement, unless specified otherwise.
  • Each pore size of a test sample may be measured to determine a distribution of pore sizes within the test sample. Other parameters may also be measured such as area, domain, periodicity, coefficient of variation, etc.
  • Multiple test samples may be taken of a larger membrane to determine that the consistency of the results properly characterizes the whole membrane. In such instance, the results may be confirmed by testing the performance of the membrane with test species. For example, if measurements indicate that certain sizes of species should be restrained from transport across the membrane, a performance test provides verification with test species. Alternatively, the performance test may be utilized as an indicator that the pore measurements will determine a concordant pore size, area, domains, periodicity, coefficient of variation, etc.
  • the size distribution of holes may be narrow, e.g., limited to 0.1-0.5 coefficient of variation.
  • the characteristic dimension of the holes is selected for the application.
  • a pore size distribution may be obtained.
  • the coefficient of variation of the pore size may be calculated herein as the ratio of the standard deviation of the pore size to the mean of the pore size as measured across the test samples.
  • the average area of perforations is an averaged measured area of pores as measured across the test samples.
  • the ratio of the area of the perforations to the ratio of the area of the sheet may be used to characterize the sheet as a density of perforations.
  • the area of a test sample may be taken as the planar area spanned by the test sample. Additional sheet surface area may be excluded due to wrinkles other non-planar features. Characterization may be based on the ratio of the area of the perforations to the test sample area as density of perforations excluding features such as surface debris. Characterization may be based on the ratio of the area of the perforations to the suspended area of the sheet. As with other testing, multiple test samples may be taken to confirm consistency across tests and verification may be obtained by performance testing.
  • the density of perforations may be, for example, 2 per nm 2 (2/ nm 2 ) to 1 per ⁇ m 2 (1/ ⁇ m 2 ).
  • the perforated area comprises 0.1% or greater, 1% or greater or 5% or greater of the sheet area, less than 10% of the sheet area, less than 15% of the sheet area, from 0.1% to 15% of the sheet area, from 1% to 15% of the sheet area, from 5% to 15% of the sheet area or from 1% to 10% of the sheet area.
  • the sheet area comprises 0.1% or greater, 1% or greater or 5% or greater of the sheet area, less than 10% of the sheet area, less than 15% of the sheet area, from 0.1% to 15% of the sheet area, from 1% to 15% of the sheet area, from 5% to 15% of the sheet area or from 1% to 10% of the sheet area.
  • a macroscale sheet is macroscopic and observable by the naked eye.
  • at least one lateral dimension of the sheet is greater than 3 cm, greater than 1 cm, greater than 1 mm or greater than 5 mm.
  • the sheet is larger than a graphene flake which would be obtained by exfoliation of graphite in known processes used to make graphene flakes.
  • the sheet has a lateral dimension greater than about 1 micrometer.
  • the lateral dimension of the sheet is less than 10 cm.
  • the sheet has a lateral dimension (e.g., perpendicular to the thickness of the sheet) from 10 nm to 10 cm or greater than 1 mm and less than 10 cm.
  • Chemical vapor deposition growth of graphene-based material typically involves use of a carbon containing precursor material, such as methane and a growth substrate.
  • the growth substrate is a metal growth substrate.
  • the metal growth substrate is a substantially continuous layer of metal rather than a grid or mesh.
  • Metal growth substrates compatible with growth of graphene and graphene-based materials include transition metals and their alloys.
  • the metal growth substrate is copper based or nickel based.
  • the metal growth substrate is copper or nickel.
  • the graphene-based material is removed from the growth substrate by dissolution of the growth substrate.
  • the sheet of graphene-based material is formed by chemical vapor deposition (CVD) followed by at least one additional conditioning or treatment step.
  • the conditioning step is selected from thermal treatment, UV-oxygen treatment, ion beam treatment, and combinations thereof.
  • thermal treatment may include heating to a temperature from 200° C to 800° C at a pressure of 10 -7 torr to atmospheric pressure for a time of 2 hours to 8 hours.
  • UV-oxygen treatment may involve exposure to light from 150 nm to 300 nm and an intensity from 10 to 100 mW/cm 2 at 6mm distance for a time from 60 to 1200 seconds.
  • UV- oxygen treatment may be performed at room temperature or at a temperature greater than room temperature.
  • UV-oxygen treatment may be performed at atmospheric pressure (e.g. 1 atm) or under vacuum.
  • ion beam treatment may involve exposure of the graphene-based material to ions having an ion energy from 50 eV to 1000 eV (for pretreatment) and the fluence is from 3 x 10 10 ions/cm 2 to 8 x 10 11 ions/cm 2 or 3 x 10 10 ions/cm 2 to 8 x 10 13 ions/cm2 (for pretreatment).
  • the source of ions may be collimated, such as a broad beam or flood source.
  • the ions may be noble gas ions such as Xe + .
  • one or more conditioning steps are performed while the graphene-based material is attached to a substrate, such as a growth substrate.
  • the conditioning treatment affects the mobility and/or volatility of the non-graphitic carbon-based material.
  • the surface mobility of the non-graphenic carbon-based material is such that when irradiated with perforation parameters such as described herein, the non-graphenic carbon-based material, may have a surface mobility such that the perforation process results ultimately in perforation.
  • hole formation is believed to be related to beam induced carbon removal from the graphene sheet and thermal replenishment of carbon in the hole region by non grapheme carbon. The replenishment process may be dependent upon energy entering the system during perforation and the resulting surface mobility of the non-graphenic carbon based material.
  • the rate of graphene removal may be higher than the non- graphenic carbon hole filling rate.
  • These competing rates depend on the non-graphenic carbon flux (e.g., mobility [viscosity and temperature] and quantity) and the graphene removal rate (e.g., particle mass, energy, flux).
  • the volatility of the non-graphenic carbon-based material may be less than that which is obtained by heating the sheet of graphene-based material to 500°C for 4 hours in vacuum or at atmospheric pressure with an inert gas.
  • CVD graphene or graphene-based material can be liberated from its growth substrate (e.g., Cu) and transferred to a supporting grid, mesh or other supporting structure.
  • the supporting structure may be configured so that at least some portions of the sheet of graphene-based material are suspended from the supporting structure. For example, at least some portions of the sheet of graphene-based material may not be in contact with the supporting structure.
  • the sheet of graphene-based material following chemical vapor deposition comprises a single layer of graphene having at least two surfaces and non- graphenic carbon based material may be provided on said surfaces of the single layer graphene.
  • the non-graphenic carbon based material may be located on one of the two surfaces or on both.
  • additional graphenic carbon may also present on the surface(s) of the single layer graphene.
  • Tunable membranes can be made by a variety of methods. For instance, a perforated graphene layer can be combined with spacer substances in solution, such that the spacer substances self-assemble to the perforated graphene layer. Then, the solution can be reduced to induce bonding between the spacer substance and the graphene layer. After that, an additional graphene layer can be added to the solution, which can bond to the graphene layer-spacer substance complex. Attachment of the additional graphene layer can be via van der Waals forces or induced covalent bonding (e.g., as a result of an applied energy such as ion radiation).
  • spacer substances are covalently bonded to at least one graphene-based material layer.
  • covalent bonding between a spacer substance and a graphene-based material layer can be induced via ion- beam induced bonding, electron-beam induced bonding, heating, chemical reactions (e.g., via reactants on - i.e., attached to - the spacer substance and the graphene-based material layer), and combinations thereof.
  • functional moieties are attached to the spacer molecules to facilitate self-assembly on or bonding to the graphene layers. In some embodiments, the functional moieties are removed in the process of making the membrane.
  • the spacer substances are trapped between two graphene-based material layers. In some embodiments the spacer substances are trapped between two graphene- based material layers, but are not restricted to a single position in the channel (i.e., they are mobile within the channel).
  • Some embodiments relate to the selective passage of substances through an enclosure that encourages nearby vascularization (i.e., angiogenesis) and/or tissue ingrowth in a biological environment.
  • Some embodiments include methods and devices for selectively separating or isolating substances in a biological environment, e.g., using a composite structure that comprises a two-dimensional material.
  • Some embodiments include an enclosure comprising a
  • the wall comprises a two-dimensional material layer and a substrate layer. Two-dimensional materials, such as graphene-based materials, are discussed below.
  • Enclosures can be in any shape.
  • the cross-section of an enclosure can be, for example, circular, ovular, rectangular, square, or irregular-shaped.
  • the size of the enclosure also is not limited, and can be small enough to circulate in the bloodstream (e.g., on the order of nanometers or larger) or large enough for implantation (e.g. on the order of inches or smaller).
  • the enclosure is from 100 nm to 6 inches long in its longest dimension, such as from about 100 nm to about 500 nm, about 500 nm to about 1 ⁇ m, about 1 ⁇ to about 500 ⁇ m, about 500 ⁇ to about 1 mm, about 1 mm to about 500 mm, about 500 mm to about 1 cm, about 1 cm to about 10 cm, or about 1 cm to about 6 inches long. In some embodiments, the enclosure is longer than 6 inches in its longest dimension, such as about 10 inches or about 15 inches long.
  • the thickness of the wall depends, in part, on the two-dimensional material layer and/or substrate layers used in the wall.
  • a wall, or a portion thereof, comprising both a two-dimensional material layer and a substrate layer is at least 5 nm thick, such as from about 5 nm to about 1 ⁇ thick, from about 5 nm to about 250 nm thick, from about 5 to about 50 nm thick, from about 5 to about 20 nm thick, or from about 20 to about 50 nm thick.
  • the thickness of the wall is about 5 nm, about 6 nm, about 7 nm, about 8 nm, about 9 nm, about 10 nm, about 11 nm, about 12 nm, about 13 nm, about 14 nm, about 15 nm, about 16 nm, about 17 nm, about 18 nm, about 19 nm, about 20 nm thick, about 25 nm thick, about 30 nm thick, about 35 nm thick, about 40 nm thick, about 45 nm thick, about 50 nm thick, about 100 nm thick, about 150 nm thick, about 200 nm thick, about 250 nm thick, about 300 nm thick, about 400 nm thick, about 500 nm thick, about 600 nm thick, about 700 nm thick, about 800, nm thick, about 900 nm thick, or about 1 ⁇ thick.
  • the thickness of the wall is up to about 1 ⁇ thick or up to about 1 mm thick. In some embodiments, the thickness of the wall is tailored to allow bidirectional passage of oxygen and nutrients into and out of the enclosure. In some embodiments, the thickness of the wall is tailored to allow entry of oxygen and nutrients into the enclosure at sufficient concentrations to maintain viability of cells within the enclosure.
  • the substrate layer has a thickness of about 1 mm or less, about 1 ⁇ or less, or about 100 nm or less. In some embodiments, a thickness of the substrate layer can range from about 100 nm to about 100 ⁇ m, or about 1 ⁇ to about 50 ⁇ m, or about 10 ⁇ to about 20 ⁇ m, or about 15 ⁇ to about 25 ⁇ . In some embodiments, the substrate layer has a thickness about 10 ⁇ or greater, or about 15 ⁇ or greater. In some embodiments, the substrate layer has a thickness of less than 1 ⁇ . In some embodiments, the substrate layer has a thickness of about 10 nm to about 100 nm, or about 20 nm to about 50 nm.
  • the enclosure can be supported by one or more support structures.
  • the support structure can itself have a porous structure wherein the pores are larger than those of the two-dimensional material.
  • the support structure is formed as a frame at a perimeter of a two-dimensional material.
  • the support structure is positioned in part interior to a perimeter of a two- dimensional material.
  • the substrate layer can convey a desired degree of structural support (e.g., to prevent tearing and/or buckling) to the two-dimensional material layer.
  • a substrate layer is positioned on one or both sides or surfaces of the two-dimensional material.
  • the substrate is positioned on the outside of the enclosure and in some cases is exposed to the external environment (see, e.g., Figure 76, showing some embodiments with a device with a substrate positioned on the outside of an enclosure).
  • the substrate is positioned on the inside of the enclosure, and can be separated from an environment external to the enclosure (even though the substrate can be separated from the environment external to the enclosure, it can still be exposed to components from the external environment due to pores in the two-dimensional material layer and/or substrate layer).
  • the substrate is positioned on both the outside and the inside of the enclosure.
  • the substrate on the outside of the enclosure can contain materials that are the same as or different from the substrate on the inside of the enclosure.
  • two or more substrate layers are positioned on the same side of the two- dimensional material layer (e.g., two or more substrate layers can be positioned on the outside of the enclosure).
  • the substrate is disposed directly on the two-dimensional material.
  • the substrate is disposed on the two-dimensional material with high conformance (e.g., by disposing a slightly wet substrate on the two-dimensional material).
  • the substrate is disclosed with low conformance.
  • the substrate is disposed indirectly on the two-dimensional material; for instance, an intermediate layer can be positioned between the substrate layer and the two-dimensional material layer. In some embodiments, the substrate layer is disposed directly or indirectly on another substrate layer. In some embodiments, the two-dimensional material is suspended on a substrate layer. In some embodiments, the substrate layer is affixed to the two-dimensional material layer (see, e.g., Figure 73 A, showing exemplary substrate layers, two-dimensional material layers, and substrate affixed to a two-dimensional material; see also Figure 73B, showing some embodiments that were determined to be not cytotoxic based on cytotoxicity testing and implantation testing).
  • the substrate layer can increase vascularization near the enclosure, thus prompting the formation of blood vessels and/or tissue ingrowth in close proximity to the enclosure.
  • the increased vascularization contributes to decreasing the effective distance between the blood stream and substances being eluted from the enclosure.
  • the increased vascularization contributes to viability of substances, such as cells, enclosed within the enclosure.
  • the substrate layer can be porous and/or nonporous. In some embodiments, the substrate layer contains porous and nonporous sections. In some embodiments the substrate layer comprises a porous or permeable fibrous layer. Porous substrates include, for example, one or more of ceramics and thin film polymers. Exemplary ceramics include nanoporous silica (silicon dioxide), silicon, SiN, and combinations thereof. In some embodiments, the substrate layer comprises track-etched polymers, expanded polymers, patterned polymers, woven polymers, and/or non-woven polymers. In some embodiments, the substrate layer comprises a plurality of polymer filaments.
  • the polymer filaments can comprise a thermopolymer, thermoplastic polymer, or melt polymer, e.g., that can be molded or set in an optional annealing step.
  • the polymer filaments are hydrophobic. In some embodiments, the polymer filaments are hydrophilic.
  • the substrate layer comprises a polymer selected from the group consisting of polysulfones, polyurethane, polymethylmethacrylate (PMMA), polyglycolid acid (PGA), polylactic acid (PLA), polyethylene glycol (PEG), polylactic-co-glycolic acid (PLGA), polyamides (such as nylon-6,6, supramid and nylamid), polyimides, polypropylene, polyethersulfones (PES), polyvinylidine fluoride (PVDF), cellulose acetate, polyethylene, polypropylene, polycarbonate, polytetrafluoroethylene (PTFE) (such as Teflon), polyvinylchloride (PVC), polyether ether ketone (PEEK), mixtures and block co-polymers of any of these, and combinations and/or mixtures thereof.
  • PMMA polymethylmethacrylate
  • PGA polyglycolid acid
  • PLA polylactic acid
  • PEG polyethylene glycol
  • PLGA polylactic-co
  • the polymers are biocompatible, bioinert and/or medical grade materials.
  • Figure 78 shows some embodiments of graphene disposed on various different substrates.
  • Figures 79 shows micrographs some embodiments of custom track-etched polyimide.
  • Figures 80 and 81 show micrographs of some embodiments of graphene disposed on track-etched polyimide.
  • Figure 82 and 83 show micrographs of some embodiments of graphene disposed on electrospun nylon 6,6.
  • the substrate layer comprises a biodegradable polymer.
  • a substrate layer forms a shell around the enclosure (e.g., completely engulfs the enclosure).
  • the substrate layer shell, or a portion thereof can be dissolved or degraded, e.g., in vitro.
  • the shell can be loaded with additives, including additives that protect substances inside the enclosure from air or prevent the need for a stabilizing agent.
  • Suitable techniques for depositing or forming a porous or permeable polymer on the two-dimensional material include casting or depositing a polymer solution onto the two- dimensional material or intermediate layer using a method such as spin-coating, spray coating, curtain coating, doctor-blading, immersion coating, electrospinning, or other similar techniques. Electrospinning techniques are described, e.g., in US 2009/0020921 and/or U.S. Application No. 14/609,325, both of which are hereby incorporated by reference in their entirety.
  • the process for forming a substrate layer includes an electrospinning process in which a plurality of polymer filaments are laid down to form a porous mat, e.g., on the two-dimensional material layer.
  • the mat has pores or voids located between deposited filaments of the fibrous layer.
  • Figure 64 shows an illustrative SEM micrograph of a graphene or graphene-based film deposited upon a plurality of electrospun PVDF fibers.
  • the electrospinning process comprises a melt
  • the polymer can be present in a spin dope at a concentration of 2 wt.% to 15 wt.%, or 5 wt.% to 10 wt.%, or about 7 wt.%.
  • Suitable solvents for the spin dope include any solvent that dissolves the polymer to be deposited and which rapidly evaporates, such as m-cresol, formic acid, dimethyl sulfoxide (DMSO), ethanol, acetone, dimethylacetamide (DMAC), dimethylformamide (DMF), water, and combinations thereof.
  • the spin dope solvent is biocompatible and/or bioinert.
  • the amount of solvent used can influence the morphology of the substrate layer.
  • dry electrospinning processes the spun fibers of the fibrous layer can remain as essentially discrete entities once deposited.
  • wet electrospinning processes deposit the spun fibers such that they are at least partially fused together when deposited.
  • the size and morphology of the deposited fiber mat e.g., degree of porosity, effective pore size, thickness of fibrous layer, gradient porosity
  • the size and morphology of the deposited fiber mat can be tailored based on the electrospinning process used.
  • the porosity of the fibrous layer can include effective void space values (e.g.
  • a single spinneret can be moved to lay down a mat of the fibrous layer. In some embodiments, multiple spinnerets can be used for this purpose.
  • the spun fibers in an electrospun fibrous layer can have a fiber diameter ranging from about 1 nm to about 100 ⁇ m, or about 10 nm to about 1 ⁇ m, or about 10 nm to about 500 nm, or about 100 nm to about 200 nm, or about 50 nm to about 120 nm, or about 1 ⁇ m to about 5 ⁇ m, or about 1 ⁇ m to about 6 ⁇ m, or about 5 ⁇ m to about 10 ⁇ m.
  • the fiber diameter is directly correlated with a depth (Z-axis) of a pore abutting the two-dimensional material (disposed in the X-Y plane), and large diameter fibers can lead to large unsupported spans of material.
  • the substrate layer can have pores (e.g., void spaces) with an effective pore size of from about 1 nm to about 100 ⁇ m, or about 10 nm to about 1 ⁇ m, or about 10 nm to about 500 nm, or about 100 nm to about 200 nm, or about 50 nm to about 120 nm, or about 1 ⁇ m to about 5 ⁇ m, or about 1 ⁇ m to about 6 ⁇ m, or about 5 ⁇ m to about 10 ⁇ m.
  • Pore diameters in the substrate layer can be measured, for example, via porometry methods (e.g., capillary flow porometry) or extrapolated via imagery.
  • the substrate layer can have an average pore size gradient throughout its thickness.
  • Pore size gradient describes a layer with a plurality of pores, where the average diameter of the pores increases or decreases based on the proximity of the pore to the two-dimensional material.
  • a fibrous layer can have an average pore size gradient that decreases nearer the surface of a graphene-based material.
  • an average pore size of the fibrous layer is smaller nearer the surface of the graphene-based material than at an opposite surface of the fibrous layer.
  • the fibrous layer can have effective pore diameters of less than about 200 nm close to the intermediate layer or the two-dimensional material layer which can increase to greater than 100 ⁇ at the maximum distance away from the intermediate layer or two-dimensional material layer.
  • the fibrous layer can have a "porosity gradient" throughout its thickness, which can be measured for instance using imagery.
  • "Porosity gradient” describes a change, along a dimension of the fibrous layer, in the porosity or total pore volume as a function of distance from the two-dimensional material layer.
  • the porosity can change in a regular or irregular manner.
  • a porosity gradient can decrease from one face of the fibrous layer to the other.
  • the lowest porosity in the fibrous layer can be located spatially closest to the two-dimensional material, and the highest porosity can be located farther away (e.g., spatially closer to an external
  • a porosity gradient of this type can be achieved by electrospinning fibers onto a two-dimensional material such that a fiber mat is denser near the surface of the two-dimensional material and less dense further from the surface of the two-dimensional material.
  • a substrate layer can have a relatively low porosity close to the two-dimensional material, a higher porosity at a mid-point of the fibrous layer thickness (which can, for example, contain a supporting mesh for reinforcement or other particles), and return to a relatively low porosity at an external surface distal to the two-dimensional material.
  • the substrate layer can have a "permeability gradient" throughout its thickness.
  • Permeability gradient describes a change, along a dimension of the fibrous layer, in the "permeability” or rate of flow of a liquid or gas through a porous material.
  • the permeability can change in a regular or irregular manner.
  • a permeability gradient can decrease from one face of the fibrous layer to the other.
  • the lowest permeability in the fibrous layer can be located spatially closest to the graphene or graphene-based film or other two-dimensional material, and the highest permeability can be located farther away.
  • permeability of a layer can increase or decrease without pore diameter or porosity changing, e.g., in response to chemical functionalization, applied pressure, voltage, or other factors.
  • both the two-dimensional material layer and the substrate layer include a plurality of pores therein.
  • both the two-dimensional material and the substrate layer contain pores, and the pores in the two-dimensional material layer are smaller, on average, than the pores in the substrate layer.
  • the median pore size in the two dimensional material layer is smaller than the median pore size in the substrate layer.
  • the substrate layer can contain pores with an average and/or median diameter of about 1 ⁇ or larger and the two-dimensional material layer can contain pores with an average and/or median diameter of about 10 nm or smaller.
  • the average and/or median diameter of pores in the two-dimensional material layer is at least about 10-fold smaller than the average and/or median diameter of pores in the substrate layer. In some embodiments, the average and/or median diameter of pores in the two-dimensional material layer is at least about 100-fold smaller than are the average and/or media diameter of pores in the substrate layer.
  • Figure 65 illustrates a portion of an enclosure in a biological environment in contact with biological tissue in which an enclosure comprises one or more substrate layers, such as fibrous layers positioned on the outside of the perforated two-dimensional material.
  • Figure 65 also shows capillary vascularization into the substrate layer.
  • the biocompatibility of graphene can further promote this application, particularly by functionalizing the graphene to improve compatibility with a particular biological environment (e.g., via available edge bonds, bulk surface functionalization, pi-bonding, and the like). Functionalization can provide enclosures having added complexity for use in treating local and systemic disease.
  • Figure 65 also shows a wall of an enclosure with a perforated two- dimensional material having hole sizes in a range that will retain cells.
  • the external biological environment abutting the enclosure (the full enclosure is not shown) in Figure 65 is separated from cells, proteins, etc., positioned inside the enclosure. As illustrated, in some embodiments implantation of such an enclosure contemplates vascularization into a substrate layer positioned on the outside of the enclosure.
  • the substrate layer can provide a scaffold for tissue growth, cell growth and/or vascularization.
  • the substrate layer or wall comprises additives, such as pharmaceuticals, cells, growth factors (e.g., VEGF), signaling molecules, cytokines, clotting factors, blood thinners, immunosuppressants, antimicrobial agents, hormones, antibodies, minerals, nutrients or combinations thereof.
  • additives such as pharmaceuticals, cells, growth factors, clotting factors, blood thinners, immunosuppressants, antimicrobial agents, hormones, antibodies, antigens (e.g., IgG-binding antigens) or an antibody- binding fragment thereof, minerals, nutrients or combinations thereof are positioned on the inside of the disclosure.
  • the substrate layer or wall comprises materials toxic to bacteria or cells (without being bound by theory, it is believed that incorporating toxic materials into the wall will prevent passage of potentially dangerous or detrimental cells across the wall).
  • additives beneficially promote cell or tissue viability or growth, reduce or prevent infection, improve vascularization to or near the enclosure, improve biocompatibility, reduce biofouling, and/or reduce the risk of adverse reactions.
  • additives can modulate properties, such as hydrophobicity or hydrophilicity, of the substrate layer.
  • additives can be used to modulate elution of a substance from a compartment in the enclosure. For instance, additives can confer shell-like properties to a substrate layer, such that degradation or removal of the additives allows substances in the compartment to escape the enclosure (and, by extension, substances from the external environment to enter to enclosure).
  • Some embodiments comprise a composited structure that include a two-dimensional material layer and a substrate layer.
  • a composite structure includes a support material (see, e.g., Figure 66D) disposed on an opposite side of the two-dimensional material from the substrate layer.
  • a composite structure comprises an intermediate layer between the two-dimensional material and the substrate layer, e.g., as shown in Figures 66A, 66C, and 66E.
  • Figure 66 shows schematic illustrations of composite structures comprising two-dimensional materials (e.g., graphene), an optional intermediate layer (e.g., track etched polymer membrane), and a fibrous layer having a tighter fiber spacing nearer the two- dimensional material and an increasing effective pore size further from the two-dimensional material.
  • Figure 66 A shows SEM micrographs of the fibrous material with (bottom two expanded micrographs) and without (top two expanded micrographs) the two-dimensional material on the surface of the fibrous material.
  • Figure 66A also shows SEM micrographs of high fiber density (bottom), medium fiber density (middle) and low fiber density (top) substrates.
  • the intermediate layer promotes adhesion between the two- dimensional material layer and the substrate layer.
  • the enclosure comprises an intermediate layer disposed between the two-dimensional material layer and the substrate layer.
  • the enclosure comprises an intermediate layer positioned between two substrate layers on the same side of the two-dimensional material layer.
  • the intermediate layer comprises carbon nanotubes, lacey carbon, nanoparticles, lithographically patterned low-dimensional materials, silicon and silicon nitride micromachined material, a fine mesh, such as a transmission electron microscopy grid, or combinations of these.
  • Figure 69 shows an illustrative schematic of a process for manufacturing a two-dimensional material on a fibrous layer with mesh reinforcement.
  • the intermediate layer can be a thin, smooth, porous polymer layer, such as a track etched polymer.
  • the intermediate layer has a thickness of from 3 nm to 10 ⁇ m, 10 nm to 10 ⁇ m, 50 nm to 10 ⁇ m, 100 nm to 10 ⁇ m, 500 nm to 10 ⁇ m, 1 ⁇ to 10 ⁇ m, or 2 ⁇ to 6 ⁇ m.
  • the composite structure has a thickness of from 1 ⁇ to 100 ⁇ m, 2 ⁇ m, to 75 ⁇ m, 3 ⁇ m, to 50 ⁇ m, 4 ⁇ m, to 40 ⁇ m, 5 ⁇ m to 30 ⁇ m, 6 ⁇ m, to 25 ⁇ m, or 6 ⁇ to 20 ⁇ m, or 6 ⁇ to 16 ⁇ m.
  • an enclosure or composite structure includes a fibrous layer affixed to multiple sheets of graphene or graphene-based material.
  • the sheets of graphene or graphene-based materials are stacked upon one another with one of the sheets affixed directly or indirectly to the fibrous layer.
  • Figure 70 shows an illustrative SEM micrograph of two layers of graphene or graphene-based material on a fibrous layer.
  • one or more sheets of graphene or graphene-based material can be affixed to a first surface of a fibrous layer and one or more sheets of graphene or graphene-based material can be affixed to a second surface of the fibrous layer.
  • the graphene- based material is applied to a fully-formed substrate layer, such as a fully-formed electrospun substrate layer.
  • Some embodiments comprise putting multiple layers of the graphene-based material onto the substrate layer (e.g., the fully-formed substrate layer). Without being bound by theory, it is believed that adding multiple layers of graphene-based material onto the substrate layer allows complete coverage of the substrate layer with the graphene-based material.
  • the enclosure comprises a single compartment that does not contain sub-compartments.
  • the single compartment is in fluid
  • the enclosure has a plurality of sub-compartments.
  • each sub-compartment is in fluid communication with an environment outside the sub-compartment.
  • each sub-compartment comprises a wall that allows passage of one or more substances into and/or out of the sub-compartment.
  • the wall or a portion thereof comprises a perforated two-dimensional material, a polymer, a hydrogel, or some other means of allowing passage of one or more substance into and/or out of the sub-compartment.
  • an enclosure is subdivided into two sub-compartments separated from each other at least in part by perforated two-dimensional material, such that the two sub-compartments are in direct fluid communication with each other through holes in the two-dimensional material.
  • the enclosure is subdivided into two sub-compartments each comprising two-dimensional material which sub- compartments are in direct fluid communication with each other through holes in the two- dimensional material and only one of the sub-compartments is in direct fluid communication with an environment external to the enclosure.
  • the enclosure is subdivided into two sub-compartments each comprising two-dimensional material which sub- compartments are in direct fluid communication with each other through holes in the two- dimensional material and both of the sub-compartments are also in direct fluid communication with an environment external to the enclosure.
  • the enclosure has an inner sub-compartment and an outer sub- compartment each comprising a perforated two-dimensional material, wherein the inner sub- compartment is entirely enclosed within the outer sub-compartment, the inner and outer compartments are in direct fluid communication with each other through holes in the two- dimensional material and the inner sub-compartment is not in direct fluid communication with an environment external to the enclosure.
  • an enclosure has a plurality of sub-compartments each comprising a two-dimensional material
  • the sub-compartments are nested one within the other, each of which sub-compartments is in direct fluid communication through holes in two- dimensional material with the sub-compartment(s) to which it is adjacent, the outermost sub- compartment in direct fluid communication with an environment external to the enclosure, the remaining plurality of sub-compartments not in direct fluid communication with an environment external to the enclosure.
  • a sub-compartment can have any shape or size. In some embodiments, 2 or 3 sub-compartments are present.
  • enclosure sub- compartments are illustrated in Figures 61 A-61E.
  • Figure 61 A a nested configuration is illustrated, such that sub-compartment B completely contains a smaller sub-compartment A, and substances in the centermost enclosure A can pass into the main enclosure B, and potentially react with or within the main compartment during ingress and egress therefrom.
  • one or more substances in A can pass into B and one or more substances in A can be retained in A and not enter B.
  • Two sub-compartments in which one or more substances can pass directly between the sub-compartments are said to be in direct fluid communication.
  • Passage between sub-compartments and between the enclosure and the external environment can be via holes of a perforated two-dimensional material.
  • the barrier e.g., a membrane
  • the barrier between compartment A and B can be permeable to all substances in A or to certain substances in A (i.e., selective permeability).
  • the barrier between B and the external environment can be permeable to all substances in B or selectively permeable to certain substances in B.
  • sub-compartment A is in direct fluid communication with sub-compartment B which in turn is in direct fluid communication with the external environment.
  • Compartment A in this nested configuration is in indirect fluid communication with the external environment via intermediate passage into sub-compartment B.
  • the two- dimensional materials employed in different sub-compartments of an enclosure can be the same or different materials and the perforations or hole sizes in the two-dimensional material of different sub-compartments can be the same or different.
  • the enclosure is bisected with an impermeable wall (e.g., formed of non-porous or non-permeable sealant) forming sub-compartments A and B, such that both sections have access to the egress location independently, but there is no direct or indirect passage of substances from A to B. (It will be appreciated, however, that substances exiting A or B can enter the other sub-compartment indirectly via the external environment.)
  • an impermeable wall e.g., formed of non-porous or non-permeable sealant
  • the main enclosure is again bisected into sub-compartments A and B, but with a perforated material forming the barrier between the sub-compartments.
  • Both sub- compartments not only have access to the egress location independently, but also can interact with one another, i.e. the sub-compartments are in direct fluid communication.
  • the barrier between sub-compartments A and B is selectively permeable, for example allowing at least one substance in A to pass into B, but not allowing the substances originating in B to pass to A.
  • the porosity of the barrier between sub-compartments e.g., sub- compartments A and B
  • Figure 6 ID illustrates an enclosure having three compartments.
  • the enclosure is illustrated with sub-compartment A being in fluid communication with sub-compartment B, which in turn is in fluid communication with sub-compartment C, which in turn is in fluid communication with the external environment.
  • Compartments A and B are not in fluid communication with the external environment, i.e. they are not in direct fluid communication with the external environment.
  • Adjacent sub-compartments A and B and adjacent sub- compartments B and C are each separated by a perforated two-dimensional material and are thus in direct fluid communication with each other.
  • Sub-compartment A is only in indirect fluid communication with compartment C and the external environment via sub-compartment B or B and C, respectively.
  • the boundaries, or at least a portion thereof, of the enclosure can be constructed from a two-dimensional material such that the thickness of the two- dimensional material is less than the diameter of the substance to be passed selectively across the two-dimensional material.
  • Figure 6 IE illustrates an enclosure having a single compartment (A) and no sub- compartments.
  • the compartment is in direct fluid communication with an environment external to the enclosure.
  • the presence of two or more sub-compartments containing the same substance(s) provides redundancy in function so that an enclosure can remain at least partially operable so long as at least one sub-compartment is not compromised.
  • the multiple physical embodiments for the enclosures and their uses can allow for various levels of interaction and scaled complexity of problems to be solved.
  • a single enclosure can provide drug elution for a given time period, or there can be multiple sizes of perforations to restrict or allow movement of distinct substances, each having a particular size.
  • Added complexity of the embodiments described herein with multiple sub- compartments can allow for interaction between compounds to catalyze or activate a secondary response (i.e., a "sense-response" paradigm).
  • a secondary response i.e., a "sense-response" paradigm.
  • exemplary compound A can undergo a constant diffusion into the body, or either after a given time or in the presence of a stimulus from the body.
  • exemplary compound A can activate exemplary compound B, or inactivate functionalization that otherwise blocks exemplary compound B from escaping.
  • binding interactions to produce the foregoing effects can be reversible or irreversible.
  • exemplary compound A can interact with chemical cascades produced outside the enclosure, and a metabolite subsequent to the interaction can release exemplary compound B (e.g., by inactivating functionalization).
  • exemplary compound B e.g., by inactivating functionalization.
  • source cells e.g., non-host; allogenic; xenogenic; autogenic; cadeaveric; stem cells, such as fully or partially differentiated stem cells
  • stem cells such as fully or partially differentiated stem cells
  • growth factors or hormones can be loaded in the enclosure to encourage vascularization (see Figure 65).
  • survival of cells within the enclosure can be improved as a result of bi-directional passage of nutrients and waste into and out of the enclosure.
  • the relative thinness of graphene can enable bi-directional passage across a wall (or portion thereof) of the enclosure in close proximity to blood vessels, particularly capillary blood vessels, and other cells.
  • using a graphene- based enclosure can provide differentiation over other solutions accomplishing the same effect because the graphene does not appreciably limit permeability; instead, the diffusion of molecules through the graphene apertures can limit the movement of a substance across the wall.
  • the perforations allow for zeroth order diffusion through the wall.
  • osmotic pumps can be used to transport substances across the wall.
  • natural delta pressures in the body influence passage of substances across the wall.
  • convective pressure influences passage of substances across the wall. In some embodiments, it is possible to achieve high throughput flux through the wall of the enclosure.
  • Figures 62A and 62B provide a schematic illustration of enclosures with a single compartment for immunoisolation (it will be appreciated that the enclosure can having a plurality of sub-compartments, for example, two or three sub-compartments).
  • the enclosure (6030) of Figure 62 A is shown as a cross-section formed by an inner sheet or layer (6031) comprising perforated two-dimensional material, such as a graphene-based material, and an outer sheet or layer (6032) of a substrate material (though in some embodiments, the inner layer comprises the substrate material, and the outer layer comprises the perforate two-dimensional material).
  • the substrate material can be porous, selectively permeable or non-porous, and/or and non- permeable.
  • Figure 62B provides an alternative cross-section of the enclosure of Figure 62 A, showing the space or cavity formed between a first composite layer (6032/6031) and a second composite layer (6032/6031) (in the figure, the cavity is depicted to contain roughly circular symbols, which can be, e.g., cells or any other substance) where a sealant 6034 is illustrated as sealing the edges of the composite layers.
  • seals at the edges of the composite layers can be formed employing physical methods, such as clamping, crimping, or with adhesives. Methods and materials for forming the seals at the edges are not particularly limiting.
  • the sealing material provides a non-porous and non-permeable seal or closure.
  • a portion of the enclosure is formed from a sealant, such as a silicone, epoxy, polyurethane or similar material.
  • the sealant is biocompatible. For instance, in some embodiments the seal does not span the entire length or width of the device.
  • the seal forms a complete loop around the cavity.
  • the seal is formed as a frame at a perimeter of a two-dimensional material.
  • the seal is positioned, at least in in part, interior to a perimeter of a two-dimensional material.
  • Some embodiments include methods for using graphene-based materials and/or other two-dimensional materials to transport, transfer, deliver, and/or allow passage of substances in or to a biological environment. Some embodiments comprise delivering substances to an environment external to the enclosure (e.g., a biological environment).
  • the substance positioned on the inside of the enclosure comprises one or more of atoms, molecules, viruses, bacteria, cells, particles and aggregates thereof.
  • the substance can include biological molecules, such as proteins (e.g., insulin), nucleic acids, DNA, and/or RNA; pharmaceuticals; drugs; medicaments; therapeutics, including biologies and small molecule drugs; and combinations thereof.
  • At least a portion of the enclosure can be permeable to oxygen and nutrients sufficient for cell growth and maintenance, to waste produced by the cell (e.g., CO 2 ), and/or to metabolites produced by the cell (e.g., insulin).
  • at least a portion of the enclosure is permeable to signaling molecules, such as glucose.
  • at least a portion of the enclosure is permeable to growth factors produced by cells, such as VEGF.
  • the enclosure is not permeable to cells (such as immune cells), viruses, bacteria, antibodies, and/or complements of the immune system. Thus, in some embodiments, cells from the external environment cannot enter the enclosure and cells in the enclosure are retained.
  • the enclosure is permeable to desirable products, such as growth factors or hormones produced by the cells (see, e.g., Figures 74 and 75, illustrating some embodiments related to immunoisolation).
  • the cells within the enclosure can be immunoisolated (i.e., protected from an immune reaction).
  • the cells are yeast cells, bacterial cells, stem cells, mammalian cells, human cells, porcine cells, or a combination thereof.
  • an enclosure comprises a plurality of sub-compartments, with the cells being positioned within one or more sub-compartments.
  • the enclosure comprises a single compartment.
  • hole sizes in perforated two-dimensional materials useful for immunoisolation range in size from 1-50 nm, 1-40 nm, 1-30 nm, 1-25 nm, 1-17 nm, 1- 15 nm, 1-12 nm, 1-10 nm, 3-50 nm, 3-30 nm, 3-20 nm, 3-10 nm, or 3-5 nm. In some
  • the size of the holes is about 1 nm, about 3 nm about 5 nm, about 10 nm, about 15 nm, about 20 nm, about 30 nm, or about 50 nm.
  • Figures 63A-63C illustrate an exemplary method for forming an enclosure and introducing selected substances, for example cells, therein. The method is illustrated with use of a sealant for forming the enclosure.
  • a first composite layer or sheet can be formed by placing a sheet or layer of two-dimensional material, such as a sheet of graphene-based material or a sheet of graphene (6141), in contact with a substrate layer (6142). At least a portion of the substrate layer (6142) of the first composite can be porous or permeable. Pore size of the substrate layer can be larger than the holes or apertures in the two-dimensional material employed and can be tuned for the environment (e.g., body cavity).
  • a layer of sealant (6144), e.g., silicone, is applied on the sheet or layer of perforated two-dimensional material outlining a compartment of the enclosure wherein the sealant will form a non-permeable seal around a perimeter of the enclosure. Formation of a single compartment is illustrated in Figures 63 A-63C, however, it will be appreciated that multiple independent compartments within an enclosure can be formed by an analogous process.
  • a second composite layer formed in the same way as the first is then prepared and positioned with the sheet or layer of perforated two dimensional materials in contact with the sealant.
  • a sealant can be applied to a portion of a composite layer and the layer can be folded over in contact with the sealant to form an enclosure. A seal is then formed between the two composite layers.
  • an alternative enclosure can be formed by applying a sheet or layer of non-porous and non-permeable support material in contact with the sealant. In this case only a portion of the enclosure is porous and permeable.
  • Other methods for sealing the enclosure include ultrasonic welding. Sealed composite layers are illustrated in Figure 63B where it is shown that the sealed layers can be trimmed to size around the sealant to form the enclosure.
  • the enclosure formed is shown to have an external porous substrate layer 6142 with the sheet or layer of perforated two-dimensional material (6141) being positioned as an internal layer, with sealant 6144 around the perimeter of the enclosure.
  • cells or other substances that would be excluded from passage through the perforated two-dimensional sheet or layer can be introduced into the enclosure after it is formed by injection through the sealant layer. Any perforation formed by such injection can be sealed as needed.
  • substances e.g., cells
  • one or more ports can be provided for introducing substances into the enclosure.
  • a loading port can be provided within the sealed perimeter of the enclosure, and the loading port can be permanently or semipermanently sealed after introduction of one or more substances through the loading port.
  • an enclosure comprises perforated two-dimensional material encapsulating a substance, such that the substance is released to an environment external to the enclosure by passage through the holes in the perforated two-dimensional material.
  • the enclosure encapsulates two or more different substances.
  • not all of the different substances are released to an environment external to the enclosure. In some embodiments, all of the different substances are released into an environment external to the enclosure. In some embodiments, different substances are released into an environment external to the enclosure at different rates. In some embodiments, different substances are released into an environment external to the enclosure at the same rates.
  • any enclosure herein at least a portion of the holes in the two-dimensional material of the enclosure are functionalized.
  • At least a portion of the two-dimensional material is conductive and a voltage can be applied to at least a portion of the conductive two-dimensional material.
  • the voltage can be an AC or DC voltage.
  • the voltage can be applied from a source external to the enclosure.
  • an enclosure device further comprises connectors and leads for application of a voltage from an external source to the two-dimensional material.
  • the conductive properties of graphene-based or other two-dimensional materials can allow for electrification to take place from an external source.
  • an AC or DC voltage can be applied to conductive two-dimensional materials (e.g., in a device such as an enclosure device).
  • the conductivity properties of graphene can provide additional gating to charged molecules or substances. Electrification can occur permanently or only a portion of the time to affect gating.
  • Directional gating of charged molecules can be directed not only through the pores (or restrict travel through pores), but also to the surface of the graphene to adsorb or bind and encourage growth, promote formation of a protective layer, or provide the basis or mechanism for other biochemical effects (e.g., on the body).
  • At least once wall, or portion thereof, of the enclosure allows for electrostatic control of charged species, for instance in nanofluidic or microfluidic systems.
  • the wall allows for control of charged species by varying the applied voltage, for instance in nanofluidic or microfluidic systems.
  • the wall can be tuned to manipulate ion passage at low and/or high ion concentrations.
  • the wall is an ion-selective membrane.
  • the wall comprises one or more voltage-gated ion channels, such as voltage-gated pores.
  • the wall mimics biological voltage-gated ion channels.
  • the wall is a solid- state membrane.
  • nanochannel or nanopore transistors can be used to manipulate ion passage.
  • the wall can be tuned using low or high applied voltages. In some embodiments, the wall allows high ionic flux. In some embodiments, the wall allows low ion flux. In some embodiments, pores in the wall modulates current of ions at low gate voltages and/or display high selectivity. In some embodiments, ion flux across the wall can be turned on or off at low applied voltages, such as ⁇ 500 mV. In some embodiments, ion flux across the wall can be turned on or off at biologically relevant ion concentrations, such as up to 1 M. In some embodiments, the applied voltage can modulate on species selectivity, e.g., cation or anion selectivity.
  • species selectivity e.g., cation or anion selectivity.
  • nanopores can be electrostatically controlled at low voltages and biologically relevant ion concentrations.
  • walls are used in separation and sensing technologies.
  • walls are used in water filtration, water desalination, water purification, osmosis, energy storage, microfluidic devices, nanofluidic devices, and/or therapeutic methods.
  • walls are used in immune-isolation (i.e., protecting substances from an immune reaction), timed drug release (e.g., sustained or delayed release), hemodialysis, and hemofiltration.
  • Some embodiments relate to methods of ultrafiltration, nanofiltration and/or microfiltration. Some embodiments comprise using gating to control release of substances. Some embodiments comprise using gating to allow for different substances to be released at different times. Some embodiments comprise allowing different substances to pass through the wall at different times, thus modulating when and how substances mix and interact with other substances in a specific order.
  • Some embodiments comprise a method comprising introducing an enclosure comprising perforated two-dimensional material into an environment, the enclosure containing at least one substance; and releasing at least a portion of the at least one substance through the holes of the two-dimensional material to the environment external to the enclosure.
  • the enclosure contains cells which are not released from the enclosure and the at least one substance, a portion of which is released, is a substance generated by the cells in the enclosure.
  • Some embodiments comprise a method comprising introducing an enclosure comprising perforated two-dimensional material to an environment, the enclosure containing at least one first substance; and allowing migration of other substances from the environment into the enclosure.
  • the first substance is cells, and other substances include nutrients and/or oxygen.
  • a composite structure comprises perforated two-dimensional material and a first fibrous layer comprising a plurality of polymer filaments affixed to a surface of the two-dimensional material; wherein the composite structure is substantially planar.
  • the perforated two-dimensional material has a second fibrous layer affixed to a surface of the two-dimensional material opposite the first fibrous layer.
  • the average pore size of the first fibrous layer is different from the average pore size of the second fibrous layer.
  • the first and/or second fibrous layer comprises an additive selected from the group consisting of pharmaceuticals, cells, growth factors, clotting factors, blood thinners, immunosuppressants, antimicrobial agents, hormones, antibodies, minerals, nutrients and combinations thereof.
  • the additive selected from the group consisting of pharmaceuticals, cells, growth factors, clotting factors, blood thinners, immunosuppressants, antimicrobial agents, hormones, antibodies, minerals, nutrients and combinations thereof.
  • substantially planar composite structure is flexible. In some embodiments, the substantially planar composite structure is rigid. In some embodiments, multiple composite structures are combined to form a pouch-like enclosure. Such planar composite structures can be useful, for example, as appliques for wound healing. The composite structures can also be used, for example, as a component of an adhesive bandage.
  • enclosures represent a disruptive technology for state of the art vehicle and other devices, such that these vehicles and devices to be used in new ways.
  • cell line developments, therapeutic releasing agents, and sensing paradigms e.g., MRSw's, MR-based magnetic relaxation switches, see; Koh et al. (2008) Ang. Chem. Int'l Ed. Engl., 47(22) 4119-4121
  • MRSw's MR-based magnetic relaxation switches
  • enclosures can be used in non-therapeutic applications, such as in dosing probiotics in dairy products.
  • two-dimensional materials are atomically thin, with thickness ranging from single-layer sub-nanometer thickness to a few nanometers.
  • Two-dimensional materials include metal chalogenides (e.g., transition metal dichalogenides), transition metal oxides, hexagonal boron nitride, graphene, silicene and germanene (see: Xu et al. (2013)
  • the two-dimensional material comprises a graphene-based material.
  • Graphene represents a form of carbon in which the carbon atoms reside within a single atomically thin sheet or a few layered sheets (e.g., about 20 or less) of fused six- membered rings forming an extended sp 2 -hybridized carbon planar lattice.
  • Graphene-based materials include, but are not limited to, single layer graphene, multilayer graphene or interconnected single or multilayer graphene domains and combinations thereof.
  • graphene-based materials also include materials which have been formed by stacking single or multilayer graphene sheets.
  • multilayer graphene includes 2 to 20 layers, 2 to 10 layers or 2 to 5 layers.
  • layers of multilayered graphene are stacked, but are less ordered in the z direction (perpendicular to the basal plane) than a thin graphite crystal.
  • a sheet of graphene-based material may be a sheet of single or multilayer graphene or a sheet comprising a plurality of interconnected single or multilayer graphene domains, which may be observed in any known manner such as using for example small angle electron diffraction, transmission electron microscopy, etc..
  • the multilayer graphene domains have 2 to 5 layers or 2 to 10 layers.
  • a domain refers to a region of a material where atoms are substantially uniformly ordered into a crystal lattice. A domain is uniform within its boundaries, but may be different from a neighboring region. For example, a single crystalline material has a single domain of ordered atoms.
  • At least some of the graphene domains are nanocrystals, having domain size from 1 to 100 nm or 10-100 nm. In some embodiments, at least some of the graphene domains have a domain size greater than from 100 nm to 1 cm, or from 100 nm to 1 micron, or from 200 nm to 800 nm, or from 300 nm to 500 nm. In some embodiments, a domain of multilayer graphene may overlap a neighboring domain. Grain boundaries formed by crystallographic defects at edges of each domain may differentiate between neighboring crystal lattices.
  • a first crystal lattice may be rotated relative to a second crystal lattice, by rotation about an axis perpendicular to the plane of a sheet, such that the two lattices differ in crystal lattice orientation.
  • the sheet of graphene-based material is a sheet of single or multilayer graphene or a combination thereof.
  • the sheet of graphene-based material is a sheet comprising a plurality of interconnected single or multilayer graphene domains.
  • the interconnected domains are covalently bonded together to form the sheet.
  • the sheet is polycrystalline.
  • the thickness of the sheet of graphene-based material is from 0.3 to 10 nm, 0.34 to 10 nm, from 0.34 to 5 nm, or from 0.34 to 3 nm. In some embodiments, the thickness includes both single layer graphene and the non-graphenic carbon.
  • a sheet of graphene-based material comprises intrinsic or native defects.
  • Intrinsic defects may result from preparation of the graphene-based material in contrast to perforations which are selectively introduced into a sheet of graphene-based material or a sheet of graphene.
  • Such intrinsic or native defects may include, but are not limited to, lattice anomalies, pores, tears, cracks or wrinkles.
  • Lattice anomalies can include, but are not limited to, carbon rings with other than 6 members (e.g. 5, 7 or 9 membered rings), vacancies, interstitial defects (including incorporation of non-carbon atoms in the lattice), and grain boundaries.
  • graphene is the dominant material in a graphene-based material.
  • a graphene-based material may comprise at least 20% graphene, at least 30%) graphene, or at least 40% graphene, or at least 50% graphene, or at least 60%> graphene, or at least 70% graphene, or at least 80% graphene, or at least 90% graphene, or at least 95% graphene.
  • a graphene-based material comprises a range of graphene selected from 30% to 95%, or from 40% to 80% from 50% to 70%, from 60% to 95% or from 75%) to 100%).
  • the amount of graphene in the graphene-based material is quantified as an atomic percentage utilizing known methods including scanning transmission electron microscope examination, or alternatively if STEM or TEM is ineffective another similar measurement technique.
  • a sheet of graphene-based material further comprises non- graphenic carbon-based material located on at least one surface of the sheet of graphene-based material.
  • the sheet is exemplified by two base surfaces (e.g. top and bottom faces of the sheet, opposing faces) and side faces (e.g. the side faces of the sheet).
  • the "bottom" face of the sheet is that face which contacted the substrate during growth of the sheet and the "free" face of the sheet opposite the "bottom” face.
  • non-graphenic carbon-based material may be located on one or both base surfaces of the sheet (e.g. the substrate side of the sheet and/or the free surface of the sheet).
  • the sheet of graphene-based material includes a small amount of one or more other materials on the surface, such as, but not limited to, one or more dust particles or similar contaminants.
  • the amount of non-graphenic carbon-based material is less than the amount of graphene. In some further embodiments, the amount of non-graphenic carbon material is three to five times the amount of graphene; this is measured in terms of mass. In some additional embodiments, the non-graphenic carbon material is characterized by a percentage by mass of said graphene-based material selected from the range of 0% to 80%. In some embodiments, the surface coverage of the sheet of non-graphenic carbon-based material is greater than zero and less than 80%, from 5% to 80%, from 10% to 80%, from 5% to 50% or from 10%) to 50%. This surface coverage may be measured with transmission electron microscopy, which gives a projection.
  • the amount of graphene in the graphene-based material is from 60% to 95% or from 75% to 100%.
  • the amount of graphene in the graphene-based material is quantified as an atomic percentage utilizing known methods preferentially using transmission electron microscope examination, or alternatively if STEM is ineffective using an atomic force microscope.
  • the non-graphenic carbon-based material does not possess long range order and is classified as amorphous.
  • the non-graphenic carbon-based material further comprises elements other than carbon and/or hydrocarbons.
  • non-carbon elements which may be incorporated in the non-graphenic carbon include hydrogen, oxygen, silicon, copper, and iron.
  • the non-graphenic carbon-based material comprises hydrocarbons.
  • carbon is the dominant material in non-graphenic carbon-based material.
  • a non-graphenic carbon-based material in some embodiments comprises at least 30% carbon, or at least 40% carbon, or at least 50% carbon, or at least 60% carbon, or at least 70% carbon, or at least 80% carbon, or at least 90% carbon, or at least 95% carbon.
  • a non-graphenic carbon-based material comprises a range of carbon selected from 30% to 95%, or from 40% to 80%), or from 50% to 70%.
  • the amount of carbon in the non-graphenic carbon-based material is quantified as an atomic percentage utilizing known methods preferentially using transmission electron microscope examination, or alternatively if STEM is ineffective using atomic force microscope.
  • Perforation techniques suitable for use in perforating the graphene-based materials may include described herein ion-based perforation methods and UV-oxygen based methods.
  • Ion-based perforation methods include methods in which the graphene-based material is irradiated with a directional source of ions.
  • the ion source is collimated.
  • the ion source is a broad beam or flood source.
  • a broad field or flood ion source can provide an ion flux which is significantly reduced compared to a focused ion beam.
  • the ion source inducing perforation of the graphene or other two- dimensional material is considered to provide a broad ion field, also commonly referred to as an ion flood source.
  • the ion flood source does not include focusing lenses.
  • the ion source is operated at less than atmospheric pressure, such as at 10- 3 to 10 -5 torr or 10 -4 to 10 -6 torr.
  • the environment also contains background amounts (e.g. on the order of 10 -5 torr) of oxygen (O 2 ), nitrogen (N 2 ) or carbon dioxide (CO 2 ).
  • the ion beam may be perpendicular to the surface of the layer(s) of the material (incidence angle of 0 degrees) or the incidence angle may be from 0 to 45 degrees, 0 to 20 degrees, 0 to 15 degrees or 0 to 10 degrees.
  • exposure to ions does not include exposure to plasma.
  • UV-oxygen based perforation methods include methods in which the graphene-based material is simultaneously exposed to ultraviolet (UV) light and an oxygen containing gas Ozone may be generated by exposure of an oxygen containing gas such as oxygen or air to the UV light. Ozone may also be supplied by an ozone generator device.
  • the UV-oxygen based perforation method further includes exposure of the graphene-based material to atomic oxygen. Suitable wavelengths of UV light include, but are not limited to wavelengths below 300 nm or from 150 nm to 300 nm. In some embodiments, the intensity from 10 to 100 mW/cm 2 at 6mm distance or 100 to 1000 mW/cm 2 at 6mm distance.
  • suitable light is emitted by mercury discharge lamps (e.g. about 185 nm and 254 nm).
  • UV/oxygen cleaning is performed at room temperature or at a temperature greater than room temperature.
  • UV/oxygen cleaning is performed at atmospheric pressure (e.g. 1 atm) or under vacuum.
  • Perforations are sized as described herein to provide desired selective permeability of a species (atom, molecule, protein, virus, cell, etc.) for a given application.
  • permeability relates to the propensity of a porous material or a perforated two-dimensional material to allow passage (or transport) of one or more species more readily or faster than other species. Selective permeability allows separation of species which exhibit different passage or transport rates. In two-dimensional materials selective permeability correlates to the dimension or size (e.g., diameter) of apertures and the relative effective size of the species. Selective permeability of the perforations in two-dimensional materials such as graphene-based materials can also depend on functionalization of perforations (if any) and the specific species. Separation or passage of two or more species in a mixture includes a change in the ratio(s) (weight or molar ratio) of the two or more species in the mixture during and after passage of the mixture through a perforated two-dimensional material.
  • the characteristic size of the perforation is from 0.3 to 10 nm, from 1 to 10 nm, from 5 to 10 nm, from 5 to 20 nm, from 10 nm to 50 nm, from 50 nm to 100 nm, from 50 nm to 150 nm, from 100 nm to 200 nm, or from 100 nm to 500 nm.
  • the average pore size is within the specified range. In some embodiments, 70% to 99%, 80% to 99%, 85% to 99% or 90 to 99% of the perforations in a sheet or layer fall within a specified range, but other pores fall outside the specified range.
  • Nanomaterials in which pores are intentionally created may be referred to as perforated graphene, perforated graphene-based materials or perforated two-dimensional materials, and the like.
  • Perforated graphene-based materials include materials in which non- carbon atoms have been incorporated at the edges of the pores.
  • Pore features and other material features may be characterized in a variety of manners including in relation to size, area, domains, periodicity, coefficient of variation, etc. For instance, the size of a pore may be assessed through quantitative image analysis utilizing images preferentially obtained through transmission electron microscopy, and if TEM is ineffective, through atomic force microscopy, and if AFM is ineffective, through scanning electron microscopy, as for example presented in Figs.
  • the boundary of the presence and absence of material identifies the contour of a pore.
  • the size of a pore may be determined by shape fitting of an expected species against the imaged pore contour where the size measurement is characterized by smallest dimension unless otherwise specified.
  • the shape may be round or oval.
  • the round shape exhibits a constant and smallest dimension equal to its diameter.
  • the width of an oval is its smallest dimension. The diameter and width measurements of the shape fitting in these instances provide the size measurement, unless specified otherwise.
  • Each pore size of a test sample may be measured to determine a distribution of pore sizes within the test sample. Other parameters may also be measured such as area, domain, periodicity, coefficient of variation, etc.
  • Multiple test samples may be taken of a larger membrane to determine that the consistency of the results properly characterizes the whole membrane. In such instance, the results may be confirmed by testing the performance of the membrane with test species. For example, if measurements indicate that certain sizes of species should be restrained from transport across the membrane, a performance test provides verification with test species. Alternatively, the performance test may be utilized as an indicator that the pore measurements will determine a concordant pore size, area, domains, periodicity, coefficient of variation, etc.
  • the size distribution of holes may be narrow, e.g., limited to 0.1-0.5 coefficient of variation.
  • the characteristic dimension of the holes is selected for the application.
  • a pore size distribution may be obtained.
  • the coefficient of variation of the pore size may be calculated herein as the ratio of the standard deviation of the pore size to the mean of the pore size as measured across the test samples.
  • the average area of perforations is an averaged measured area of pores as measured across the test samples.
  • the ratio of the area of the perforations to the ratio of the area of the sheet may be used to characterize the sheet as a density of perforations.
  • the area of a test sample may be taken as the planar area spanned by the test sample. Additional sheet surface area may be excluded due to wrinkles other non-planar features. Characterization may be based on the ratio of the area of the perforations to the test sample area as density of perforations excluding features such as surface debris. Characterization may be based on the ratio of the area of the perforations to the suspended area of the sheet.
  • multiple test samples may be taken to confirm consistency across tests and verification may be obtained by performance testing.
  • the density of perforations may be, for example, 2 per nm 2 (2/ nm 2 to 1 per ⁇ m 2 (1/ ⁇ m 2 )).
  • the perforated area comprises 0.1% or greater, 1% or greater or 5%) or greater of the sheet area, less than 10% of the sheet area, less than 15% of the sheet area, from 0.1% to 15% of the sheet area, from 1% to 15% of the sheet area, from 5% to 15% of the sheet area or from 1% to 10% of the sheet area.
  • the perforations are located over greater than 10% or greater than 15% of said area of said sheet of graphene-based material.
  • a macroscale sheet is macroscopic and observable by the naked eye.
  • at least one lateral dimension of the sheet is greater than 3 cm, greater than 1 cm, greater than 1 mm or greater than 5 mm.
  • the sheet is larger than a graphene flake which would be obtained by exfoliation of graphite in known processes used to make graphene flakes.
  • the sheet has a lateral dimension greater than about 1 micrometer.
  • the lateral dimension of the sheet is less than 10 cm.
  • the sheet has a lateral dimension (e.g., perpendicular to the thickness of the sheet) from 10 nm to 10 cm or greater than 1 mm and less than 10 cm.
  • Chemical vapor deposition growth of graphene-based material typically involves use of a carbon containing precursor material, such as methane and a growth substrate.
  • the growth substrate is a metal growth substrate.
  • the metal growth substrate is a substantially continuous layer of metal rather than a grid or mesh.
  • Metal growth substrates compatible with growth of graphene and graphene-based materials include transition metals and their alloys.
  • the metal growth substrate is copper based or nickel based.
  • the metal growth substrate is copper or nickel.
  • the graphene-based material is removed from the growth substrate by dissolution of the growth substrate.
  • the sheet of graphene-based material is formed by chemical vapor deposition (CVD) followed by at least one additional conditioning or treatment step.
  • the conditioning step is selected from thermal treatment, UV-oxygen treatment, ion beam treatment, and combinations thereof.
  • thermal treatment may include heating to a temperature from 200° C to 800° C at a pressure of 10 -7 torr to atmospheric pressure for a time of 2 hours to 8 hours.
  • UV-oxygen treatment may involve exposure to light from 150 nm to 300 nm and an intensity from 10 to 100 mW/cm 2 at 6mm distance for a time from 60 to 1200 seconds.
  • UV- oxygen treatment may be performed at room temperature or at a temperature greater than room temperature.
  • UV-oxygen treatment may be performed at atmospheric pressure (e.g. 1 atm) or under vacuum.
  • ion beam treatment may involve exposure of the graphene-based material to ions having an ion energy from 50 eV to 1000 eV (for pretreatment) and the fluence is from 3 x 10 10 ions/cm 2 to 8 x 10 11 ions/cm 2 or 3 x
  • the source of ions may be collimated, such as a broad beam or flood source.
  • the ions may be noble gas ions such as Xe + .
  • one or more conditioning steps are performed while the graphene-based material is attached to a substrate, such as a growth substrate.
  • the conditioning treatment affects the mobility and/or volatility of the non-graphitic carbon-based material.
  • the surface mobility of the non-graphenic carbon-based material is such that when irradiated with perforation parameters such as described herein, the non-graphenic carbon-based material, may have a surface mobility such that the perforation process results ultimately in perforation.
  • hole formation is believed to be related to beam induced carbon removal from the graphene sheet and thermal replenishment of carbon in the hole region by non grapheme carbon. The replenishment process may be dependent upon energy entering the system during perforation and the resulting surface mobility of the non-graphenic carbon based material.
  • the rate of graphene removal may be higher than the non- graphenic carbon hole filling rate.
  • These competing rates depend on the non-graphenic carbon flux (e.g., mobility [viscosity and temperature] and quantity) and the graphene removal rate (e.g., particle mass, energy, flux).
  • the volatility of the non-graphenic carbon-based material may be less than that which is obtained by heating the sheet of graphene-based material to 500°C for 4 hours in vacuum or at atmospheric pressure with an inert gas.
  • CVD graphene or graphene-based material can be liberated from its growth substrate (e.g., Cu) and transferred to a supporting grid, mesh or other supporting structure.
  • the supporting structure may be configured so that at least some portions of the sheet of graphene-based material are suspended from the supporting structure. For example, at least some portions of the sheet of graphene-based material may not be in contact with the supporting structure.
  • the sheet of graphene-based material following chemical vapor deposition comprises a single layer of graphene having at least two surfaces and non- graphenic carbon based material may be provided on said surfaces of the single layer graphene.
  • the non-graphenic carbon based material may be located on one of the two surfaces or on both.
  • additional graphenic carbon may also present on the surface(s) of the single layer graphene.
  • enclosures can be further modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the disclosure. Accordingly, the enclosures and methods are not limited by the foregoing description.
  • permeability results for Allura Red AC and silver nanoparticles through the control membrane were also normalized to each other (based on the raw data, permeability of Allura Red AC through the control membrane high than permeability of silver nanoparticles through the control membrane).
  • the data shows that less Allura Red AC permeated the perforated graphene layer than the SiN layer.
  • the perforated graphene layer restricted silver nanoparticles from traversing the layer, as compared to the SiN layer.
  • Figure 86 compares the permeability results in Figure 85 with permeability data obtained on fluorescein alone (i.e., not conjugated to IgG). The Figure demonstrates that fluorescein permeability was higher than IgG permeability.
  • FluoSpheres added to the left side of diffusion cell did not traverse the perforated graphene.
  • fluorescein added to the left side of the diffusion cell traversed the perforated graphene, and then was detected on the right side of the diffusion cell.
  • TEPI-400/7 coated with two layers of unperforated graphene (“SLG2 Unperf); (iii) uncoated substrate TEPI-460/25; (iv) TEPI-460/25 coated with two layers of unperforated graphene; and (v) TEPI-460/25 coated with two layers of perforated graphene, where the graphene was perforated with silver nanoparticles.
  • Figure 89A and 89B show diffusion for small fluorescent dye molecules (fluorescein, Figure 89A) and large 100nm FluoSpheres (Figure 89B) through uncoated substrate,
  • Donor concentrations were 5 ⁇ for fluorescein and 200ppm for FluoSpheres.
  • the substrate was a track-etched polymeric membrane with pore diameters ranging between approximately 350-450 nm. Sample area available for diffusion was 49 mm A 2. Testing was performed at room temperature.
  • Some embodiments relate to the selective passage of substances through an enclosure that encourages nearby vascularization (i.e., angiogenesis) and/or tissue ingrowth in a biological environment.
  • Some embodiments include methods and devices for selectively separating or isolating substances in a biological environment, e.g., using a composite structure that comprises a two-dimensional material.
  • Some embodiments include an enclosure comprising a
  • the wall comprises a two-dimensional material layer and a substrate layer. Two-dimensional materials, such as graphene-based materials, are discussed below.
  • Enclosures can be in any shape.
  • the cross-section of an enclosure can be, for example, circular, ovular, rectangular, square, or irregular-shaped.
  • the size of the enclosure also is not limited, and can be small enough to circulate in the bloodstream (e.g., on the order of nanometers or larger) or large enough for implantation (e.g. on the order of inches or smaller).
  • the enclosure is from 100 nm to 6 inches long in its longest dimension, such as from about 100 nm to about 500 nm, about 500 nm to about 1 ⁇ m, about 1 ⁇ to about 500 ⁇ m, about 500 ⁇ to about 1 mm, about 1 mm to about 500 mm, about 500 mm to about 1 cm, about 1 cm to about 10 cm, or about 1 cm to about 6 inches long. In some embodiments, the enclosure is longer than 6 inches in its longest dimension, such as about 10 inches or about 15 inches long.
  • the thickness of the wall depends, in part, on the two-dimensional material layer and/or substrate layers used in the wall.
  • a wall, or a portion thereof, comprising both a two-dimensional material layer and a substrate layer is at least 5 nm thick, such as from about 5 nm to about 1 ⁇ thick, from about 5 nm to about 250 nm thick, from about 5 to about 50 nm thick, from about 5 to about 20 nm thick, or from about 20 to about 50 nm thick.
  • the thickness of the wall is about 5 nm, about 6 nm, about 7 nm, about 8 nm, about 9 nm, about 10 nm, about 11 nm, about 12 nm, about 13 nm, about 14 nm, about 15 nm, about 16 nm, about 17 nm, about 18 nm, about 19 nm, about 20 nm thick, about 25 nm thick, about 30 nm thick, about 35 nm thick, about 40 nm thick, about 45 nm thick, about 50 nm thick, about 100 nm thick, about 150 nm thick, about 200 nm thick, about 250 nm thick, about 300 nm thick, about 400 nm thick, about 500 nm thick, about 600 nm thick, about 700 nm thick, about 800, nm thick, about 900 nm thick, or about 1 ⁇ thick.
  • the thickness of the wall is up to about 1 ⁇ thick or up to about 1 mm thick. In some embodiments, the thickness of the wall is tailored to allow bidirectional passage of oxygen and nutrients into and out of the enclosure. In some embodiments, the thickness of the wall is tailored to allow entry of oxygen and nutrients into the enclosure at sufficient concentrations to maintain viability of cells within the enclosure.
  • the substrate layer has a thickness of about 1 mm or less, about 1 ⁇ or less, or about 100 nm or less. In some embodiments, a thickness of the substrate layer can range from about 100 nm to about 100 ⁇ m, or about 1 ⁇ to about 50 ⁇ m, or about 10 ⁇ to about 20 ⁇ m, or about 15 ⁇ to about 25 ⁇ . In some embodiments, the substrate layer has a thickness about 10 ⁇ or greater, or about 15 ⁇ or greater. In some embodiments, the substrate layer has a thickness of less than 1 ⁇ . In some embodiments, the substrate layer has a thickness of about 10 nm to about 100 nm, or about 20 nm to about 50 nm.
  • the enclosure can be supported by one or more support structures.
  • the support structure can itself have a porous structure wherein the pores are larger than those of the two-dimensional material.
  • the support structure is formed as a frame at a perimeter of a two-dimensional material.
  • the support structure is positioned in part interior to a perimeter of a two- dimensional material.
  • the substrate layer can convey a desired degree of structural support (e.g., to prevent tearing and/or buckling) to the two-dimensional material layer.
  • a substrate layer is positioned on one or both sides or surfaces of the two-dimensional material.
  • the substrate is positioned on the outside of the enclosure and in some cases is exposed to the external environment (see, e.g., Figure 76, showing some embodiments with a device with a substrate positioned on the outside of an enclosure).
  • the substrate is positioned on the inside of the enclosure, and can be separated from an environment external to the enclosure (even though the substrate can be separated from the environment external to the enclosure, it can still be exposed to components from the external environment due to pores in the two-dimensional material layer and/or substrate layer).
  • the substrate is positioned on both the outside and the inside of the enclosure.
  • the substrate on the outside of the enclosure can contain materials that are the same as or different from the substrate on the inside of the enclosure.
  • two or more substrate layers are positioned on the same side of the two- dimensional material layer (e.g., two or more substrate layers can be positioned on the outside of the enclosure).
  • the substrate is disposed directly on the two-dimensional material.
  • the substrate is disposed on the two-dimensional material with high conformance (e.g., by disposing a slightly wet substrate on the two-dimensional material).
  • the substrate is disclosed with low conformance.
  • the substrate is disposed indirectly on the two-dimensional material; for instance, an intermediate layer can be positioned between the substrate layer and the two-dimensional material layer. In some embodiments, the substrate layer is disposed directly or indirectly on another substrate layer. In some embodiments, the two-dimensional material is suspended on a substrate layer. In some embodiments, the substrate layer is affixed to the two-dimensional material layer (see, e.g., Figure 73 A, showing exemplary substrate layers, two-dimensional material layers, and substrate affixed to a two-dimensional material; see also Figure 73B, showing some embodiments that were determined to be not cytotoxic based on cytotoxicity testing and implantation testing).
  • the substrate layer can increase vascularization near the enclosure, thus prompting the formation of blood vessels and/or tissue ingrowth in close proximity to the enclosure.
  • the increased vascularization contributes to decreasing the effective distance between the blood stream and substances being eluted from the enclosure.
  • the increased vascularization contributes to viability of substances, such as cells, enclosed within the enclosure.
  • the substrate layer can be porous and/or nonporous. In some embodiments, the substrate layer contains porous and nonporous sections. In some embodiments the substrate layer comprises a porous or permeable fibrous layer. Porous substrates include, for example, one or more of ceramics and thin film polymers. Exemplary ceramics include nanoporous silica (silicon dioxide), silicon, SiN, and combinations thereof. In some embodiments, the substrate layer comprises track-etched polymers, expanded polymers, patterned polymers, woven polymers, and/or non-woven polymers. In some embodiments, the substrate layer comprises a plurality of polymer filaments.
  • the polymer filaments can comprise a thermopolymer, thermoplastic polymer, or melt polymer, e.g., that can be molded or set in an optional annealing step.
  • the polymer filaments are hydrophobic. In some embodiments, the polymer filaments are hydrophilic.
  • the substrate layer comprises a polymer selected from the group consisting of polysulfones, polyurethane, polymethylmethacrylate (PMMA), polyglycolid acid (PGA), polylactic acid (PLA), polyethylene glycol (PEG), polylactic-co-glycolic acid (PLGA), polyamides (such as nylon-6,6, supramid and nylamid), polyimides, polypropylene, polyethersulfones (PES), polyvinylidine fluoride (PVDF), cellulose acetate, polyethylene, polypropylene, polycarbonate, polytetrafluoroethylene (PTFE) (such as Teflon), polyvinylchloride (PVC), polyether ether ketone (PEEK), mixtures and block co-polymers of any of these, and combinations and/or mixtures thereof.
  • the polymers are biocompatible, bioinert and/or medical grade materials.
  • Figure 78 shows some embodiments of graphene
  • Figures 79 shows micrographs some embodiments of custom track-etched polyimide.
  • Figures 80 and 81 show micrographs of some embodiments of graphene disposed on track-etched polyimide.
  • Figure 82 and 83 show micrographs of some embodiments of graphene disposed on electrospun nylon 6,6.
  • the substrate layer comprises a biodegradable polymer.
  • a substrate layer forms a shell around the enclosure (e.g., it completely engulfs the enclosure).
  • the substrate layer shell, or a portion thereof can be dissolved or degraded, e.g., in vitro.
  • the shell can be loaded with additives, including additives that protect substances inside the enclosure from air or prevent the need for a stabilizing agent.
  • Suitable techniques for depositing or forming a porous or permeable polymer on the two-dimensional material include casting or depositing a polymer solution onto the two- dimensional material or intermediate layer using a method such as spin-coating, spray coating, curtain coating, doctor-blading, immersion coating, electrospinning, or other similar techniques. Electrospinning techniques are described, e.g., in US 2009/0020921 and/or U.S. Application No. 14/609,325, both of which are hereby incorporated by reference in their entirety.
  • the process for forming a substrate layer includes an electrospinning process in which a plurality of polymer filaments are laid down to form a porous mat, e.g., on the two-dimensional material layer.
  • the mat has pores or voids located between deposited filaments of the fibrous layer.
  • Figure 64 shows an illustrative SEM micrograph of a graphene or graphene-based film deposited upon a plurality of electrospun PVDF fibers.
  • the electrospinning process comprises a melt
  • the polymer can be present in a spin dope at a concentration of 2 wt.% to 15 wt.%, or 5 wt.% to 10 wt.%, or about 7 wt.%.
  • Suitable solvents for the spin dope include any solvent that dissolves the polymer to be deposited and which rapidly evaporates, such as m-cresol, formic acid, dimethyl sulfoxide (DMSO), ethanol, acetone, dimethylacetamide (DMAC), dimethylformamide (DMF), water, and combinations thereof.
  • the spin dope solvent is biocompatible and/or bioinert.
  • the amount of solvent used can influence the morphology of the substrate layer.
  • the spun fibers of the fibrous layer can remain as essentially discrete entities once deposited.
  • wet electrospinning processes deposit the spun fibers such that they are at least partially fused together when deposited.
  • the size and morphology of the deposited fiber mat e.g., degree of porosity, effective pore size, thickness of fibrous layer, gradient porosity
  • the porosity of the fibrous layer can include effective void space values (e.g.
  • a single spinneret can be moved to lay down a mat of the fibrous layer. In some embodiments, multiple spinnerets can be used for this purpose.
  • the spun fibers in an electrospun fibrous layer can have a fiber diameter ranging from about 1 nm to about 100 ⁇ m, or about 10 nm to about 1 ⁇ m, or about 10 nm to about 500 nm, or about 100 nm to about 200 nm, or about 50 nm to about 120 nm, or about 1 ⁇ to about 5 ⁇ m, or about 1 ⁇ to about 6 ⁇ m, or about 5 ⁇ to about 10 ⁇ .
  • the fiber diameter is directly correlated with a depth (Z-axis) of a pore abutting the two-dimensional material (disposed in the X-Y plane), and large diameter fibers can lead to large unsupported spans of material.
  • the substrate layer can have pores (e.g., void spaces) with an effective pore size of from about 1 nm to about 100 ⁇ m, or about 10 nm to about 1 ⁇ m, or about 10 nm to about 500 nm, or about 100 nm to about 200 nm, or about 50 nm to about 120 nm, or about 1 ⁇ to about 5 ⁇ m, or about 1 ⁇ to about 6 ⁇ m, or about 5 ⁇ to about 10 ⁇ .
  • Pore diameters in the substrate layer can be measured, for example, via porometry methods (e.g., capillary flow porometry) or extrapolated via imagery.
  • the substrate layer can have an average pore size gradient throughout its thickness.
  • Pore size gradient describes a layer with a plurality of pores, where the average diameter of the pores increases or decreases based on the proximity of the pore to the two-dimensional material.
  • a fibrous layer can have an average pore size gradient that decreases nearer the surface of a graphene-based material.
  • an average pore size of the fibrous layer is smaller nearer the surface of the graphene-based material than at an opposite surface of the fibrous layer.
  • the fibrous layer can have effective pore diameters of less than about 200 nm close to the intermediate layer or the two-dimensional material layer which can increase to greater than 100 ⁇ at the maximum distance away from the intermediate layer or two-dimensional material layer.
  • the fibrous layer can have a "porosity gradient" throughout its thickness, which can be measured for instance using imagery.
  • "Porosity gradient” describes a change, along a dimension of the fibrous layer, in the porosity or total pore volume as a function of distance from the two-dimensional material layer.
  • the porosity can change in a regular or irregular manner.
  • a porosity gradient can decrease from one face of the fibrous layer to the other.
  • the lowest porosity in the fibrous layer can be located spatially closest to the two-dimensional material, and the highest porosity can be located farther away (e.g., spatially closer to an external
  • a porosity gradient of this type can be achieved by electrospinning fibers onto a two-dimensional material such that a fiber mat is denser near the surface of the two-dimensional material and less dense further from the surface of the two-dimensional material.
  • a substrate layer can have a relatively low porosity close to the two-dimensional material, a higher porosity at a mid-point of the fibrous layer thickness (which can, for example, contain a supporting mesh for reinforcement or other particles), and return to a relatively low porosity at an external surface distal to the two-dimensional material.
  • the substrate layer can have a "permeability gradient" throughout its thickness.
  • Permeability gradient describes a change, along a dimension of the fibrous layer, in the "permeability” or rate of flow of a liquid or gas through a porous material.
  • the permeability can change in a regular or irregular manner.
  • a permeability gradient can decrease from one face of the fibrous layer to the other.
  • the lowest permeability in the fibrous layer can be located spatially closest to the graphene or graphene-based film or other two-dimensional material, and the highest permeability can be located farther away.
  • permeability of a layer can increase or decrease without pore diameter or porosity changing, e.g., in response to chemical functionalization, applied pressure, voltage, or other factors.
  • both the two-dimensional material layer and the substrate layer include a plurality of pores therein.
  • both the two-dimensional material and the substrate layer contain pores, and the pores in the two-dimensional material layer are smaller, on average, than the pores in the substrate layer.
  • the median pore size in the two dimensional material layer is smaller than the median pore size in the substrate layer.
  • the substrate layer can contain pores with an average and/or median diameter of about 1 ⁇ or larger and the two-dimensional material layer can contain pores with an average and/or median diameter of about 10 nm or smaller.
  • the average and/or median diameter of pores in the two-dimensional material layer is at least about 10-fold smaller than the average and/or median diameter of pores in the substrate layer. In some embodiments, the average and/or median diameter of pores in the two-dimensional material layer is at least about 100-fold smaller than are the average and/or media diameter of pores in the substrate layer.
  • Some embodiments comprise an enclosure with low or no toxicity, such as cytotoxicity.
  • the enclosure is not cytotoxic when implanted into a subject.
  • the enclosure is not cytotoxic to cells, skin, blood, bodily fluids, or muscle.
  • the enclosure is not cytotoxic when injected into a subject.
  • the enclosure is not cytotoxic when ingested by a subject.
  • the enclosure is not cytotoxic when used in vitro.
  • Some embodiments comprise a two-dimensional material (e.g., a graphene based material), such as a porous two-dimensional material, with low or no toxicity, such as cytotoxicity.
  • the two-dimensional material is not cytotoxic to cells, skin, blood, bodily fluids, or muscle.
  • the two-dimensional material is not cytotoxic when implanted into a subject.
  • the two-dimensional material is not cytotoxic when injected into a subject.
  • the two-dimensional material is not cytotoxic when ingested by a subject.
  • the two-dimensional material is not cytotoxic when used in vitro.
  • a two-dimensional material can be affixed to or disposed on a second material ⁇ e.g., a substrate) without substantially affecting the cytotoxicity of the second material.
  • affixing the two-dimensional material to (or disposing it on) the second material can reduce cytotoxicity of the second material.
  • Some embodiments comprise a composite structure with low or no toxicity, such as cytotoxicity.
  • the composite structure is not cytotoxic to cells, skin, blood, bodily fluids, or muscle.
  • the composite structure is not cytotoxic when implanted into a subject.
  • the composite structure is not cytotoxic when injected into a subject.
  • the composite structure is not cytotoxic when ingested by a subject.
  • the composite structure is not cytotoxic when used in vitro.
  • Cytotoxicity can be measured, for instance, using cell viability assays or implantation testing. In some embodiments, greater than about 70% of cells exposed to the enclosure and/or composite structure remain viable at least 24 hours after exposure. In some embodiments, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 98%, or at least about 99% of cells exposed to the enclosure and/or composite structure remain viable at least 24 hours after exposure.
  • the device, enclosure and/or composite material has a bioreactivity rating of about 8.9 or less, such as from about 3.0 to about 8.9, or about 0.0 to about 2.9. In some embodiments, the device, enclosure and/or composite material has a bioreactivity rating of about 0.0, about 0.5, about 0.7, about 1.0, about 1.5, about 2.0, about 2.2, about 2.5, or about 2.9.
  • tissue surrounding an implanted enclosure and/or composite structure do not exhibit substantial signs of cytotoxicity.
  • the enclosure and/or composite structure causes no, mild, or moderate signs of inflammation, encapsulation, hemorrhage, necrosis, discoloration, polymorphonuclear cells, lymphocytes, plasma cells, macrophages, giant cells, necrosis, neovascularization, fibrosis, fatty infiltrate, or combinations thereof in tissues exposed to the enclosure and/or composite structure.
  • macroscopic evaluation of tissue exposed to the enclosure and/or composite structure reveals no signs of inflammation, encapsulation, hemorrhage, necrosis, discoloration, or combinations thereof.
  • macroscopic evaluation of tissue exposed to the enclosure and/or composite structure reveals mild or moderate signs of inflammation, encapsulation, hemorrhage, necrosis, discoloration, or combinations thereof.
  • microscopic evaluation of tissue exposed to the enclosure and/or composite structure reveals no signs an inflammatory response, such as signs of polymorphonuclear cells, lymphocytes, plasma cells, macrophages, giant cells, necrosis, or combinations thereof. In some embodiments, microscopic evaluation of tissue exposed to the enclosure and/or composite structure reveals minimal or mild signs an inflammatory response, such as signs of polymorphonuclear cells, lymphocytes, plasma cells, macrophages, giant cells, necrosis, or combinations thereof. In some embodiments, microscopic evaluation of tissue exposed to the enclosure and/or composite structure reveals no signs a healing response, such as neovascularization, fibrosis, fatty infiltrate, or combinations thereof. In some embodiments, microscopic evaluation of tissue exposed to the enclosure and/or composite structure reveals minimal or mild signs a healing response, such as neovascularization, fibrosis, fatty infiltrate, or combinations thereof.
  • extent of cytotoxicity is classified based on macroscopic or microscopic evaluation, and classification can be relative to cytotoxicity of a control enclosure and/or structure.
  • no, mild, or moderate signs of inflammation, encapsulation, hemorrhage, necrosis, discoloration, polymorphonuclear cells, lymphocytes, plasma cells, macrophages, giant cells, necrosis, neovascularization, fibrosis, fatty infiltrate, or combinations thereof are as compared to a control (e.g., in some embodiments, the enclosure and/or composite structure has no signs of inflammation if observed inflammation is less than is observed using a control).
  • Some embodiments comprise methods of releasing a substance into an environment from an enclosure with low or no toxicity (e.g., cytotoxicity) to the environment. Some embodiments comprise treating a condition or disease, such as diabetes, by an enclosure with low or no cytotoxicity into the subject. Some embodiments comprise using the non-cytotoxic or low-cytotoxic enclosure in methods of immunoisolation (i.e., protecting substances from an immune reaction), timed drug release (e.g., sustained or delayed release), hemodialysis, or hemofiltration.
  • immunoisolation i.e., protecting substances from an immune reaction
  • timed drug release e.g., sustained or delayed release
  • hemodialysis hemodialysis
  • Some embodiments comprise encapsulating a device with a composite structure comprising (a) a perforated graphene-based material layer and (b) a substrate layer affixed directly or indirectly to at least one surface of the perforated graphene-based material.
  • the encapsulated device has a reduced cytotoxicity as compared to a comparable device without a perforated graphene-based material layer.
  • Some embodiments comprise methods of coating a therapeutic device with the composite structure.
  • the composite structure is applied to the exterior of the therapeutic device.
  • Some embodiments comprise the coated therapeutic device.
  • the coated therapeutic device has a lower toxicity (e.g., cytotoxicity) than a comparable therapeutic device that is not coated with the composite structure.
  • Figure 65 illustrates a portion of an enclosure in a biological environment in contact with biological tissue in which an enclosure comprises one or more substrate layers, such as fibrous layers positioned on the outside of the perforated two-dimensional material.
  • Figure 65 also shows capillary vascularization into the substrate layer.
  • the biocompatibility of graphene can further promote this application, particularly by functionalizing the graphene to improve compatibility with a particular biological environment (e.g., via available edge bonds, bulk surface functionalization, pi-bonding, and the like). Functionalization can provide enclosures having added complexity for use in treating local and systemic disease.
  • Figure 65 also shows a wall of an enclosure with a perforated two- dimensional material having hole sizes in a range that will retain cells.
  • the substrate layer can provide a scaffold for tissue growth, cell growth and/or vascularization.
  • the substrate layer or wall comprises additives, such as pharmaceuticals, cells, growth factors (e.g., VEGF), signaling molecules, cytokines, clotting factors, blood thinners, immunosuppressants, antimicrobial agents, hormones, antibodies, minerals, nutrients or combinations thereof.
  • additives such as pharmaceuticals, cells, growth factors, clotting factors, blood thinners, immunosuppressants, antimicrobial agents, hormones, antibodies, antigens (e.g., IgG-binding antigens) or an antibody- binding fragment thereof, minerals, nutrients or combinations thereof are positioned on the inside of the disclosure.
  • the substrate layer or wall comprises materials toxic to bacteria or cells (without being bound by theory, it is believed that incorporating toxic materials into the wall will prevent passage of potentially dangerous or detrimental cells across the wall).
  • additives beneficially promote cell or tissue viability or growth, reduce or prevent infection, improve vascularization to or near the enclosure, improve biocompatibility, reduce biofouling, and/or reduce the risk of adverse reactions.
  • additives can modulate properties, such as hydrophobicity or hydrophilicity, of the substrate layer.
  • additives can be used to modulate elution of a substance from a compartment in the enclosure. For instance, additives can confer shell-like properties to a substrate layer, such that degradation or removal of the additives allows substances in the compartment to escape the enclosure (and, by extension, substances from the external environment to enter to enclosure).
  • Some embodiments comprise a composited structure that include a two-dimensional material layer and a substrate layer.
  • a composite structure includes a support material (see, e.g., Figure 66D) disposed on an opposite side of the two-dimensional material from the substrate layer.
  • a composite structure comprises an intermediate layer between the two-dimensional material and the substrate layer, e.g., as shown in Figures 66A, 66C and 66E.
  • Figure 66 shows schematic illustrations of composite structures comprising two-dimensional materials (e.g., graphene), an optional intermediate layer (e.g., track etched polymer membrane), and a fibrous layer having a tighter fiber spacing nearer the two- dimensional material and an increasing effective pore size further from the two-dimensional material.
  • Figure 66 A shows SEM micrographs of the fibrous material with (bottom two expanded micrographs) and without (top two expanded micrographs) the two-dimensional material on the surface of the fibrous material.
  • Figure 66A also shows SEM micrographs of high fiber density (bottom), medium fiber density (middle) and low fiber density (top) substrates.
  • the intermediate layer promotes adhesion between the two- dimensional material layer and the substrate layer.
  • the enclosure comprises an intermediate layer disposed between the two-dimensional material layer and the substrate layer.
  • the enclosure comprises an intermediate layer positioned between two substrate layers on the same side of the two-dimensional material layer.
  • the intermediate layer comprises carbon nanotubes, lacey carbon, nanoparticles, lithographically patterned low-dimensional materials, silicon and silicon nitride micromachined material, a fine mesh, such as a transmission electron microscopy grid, or combinations of these.
  • Figure 69 shows an illustrative schematic of a process for manufacturing a two-dimensional material on a fibrous layer with mesh reinforcement.
  • the intermediate layer can be a thin, smooth, porous polymer layer, such as a track etched polymer.
  • the intermediate layer has a thickness of from 3 nm to 10 ⁇ m, 10 nm to 10 ⁇ m, 50 nm to 10 ⁇ m, 100 nm to 10 ⁇ m, 500 nm to 10 ⁇ m, 1 ⁇ to 10 ⁇ m, or 2 ⁇ to 6 ⁇ .
  • the composite structure has a thickness of from 1 ⁇ to 100 ⁇ m, 2 ⁇ to 75 ⁇ m, 3 ⁇ to 50 ⁇ m, 4 ⁇ to 40 ⁇ m, 5 ⁇ to 30 ⁇ m, 6 ⁇ to 25 ⁇ m, or 6 ⁇ to 20 ⁇ m, or 6 ⁇ to 16 ⁇ .
  • an enclosure or composite structure includes a fibrous layer affixed to multiple sheets of graphene or graphene-based material.
  • the sheets of graphene or graphene-based materials are stacked upon one another with one of the sheets affixed directly or indirectly to the fibrous layer.
  • Figure 70 shows an illustrative SEM micrograph of two layers of graphene or graphene-based material on a fibrous layer.
  • one or more sheets of graphene or graphene-based material can be affixed to a first surface of a fibrous layer and one or more sheets of graphene or graphene-based material can be affixed to a second surface of the fibrous layer.
  • the graphene- based material is applied to a fully-formed substrate layer, such as a fully-formed electrospun substrate layer.
  • Some embodiments comprise putting multiple layers of the graphene-based material onto the substrate layer (e.g., the fully-formed substrate layer). Without being bound by theory, it is believed that adding multiple layers of graphene-based material onto the substrate layer allows complete coverage of the substrate layer with the graphene-based material.
  • the enclosure comprises a single compartment that does not contain sub-compartments.
  • the single compartment is in fluid
  • the enclosure has a plurality of sub-compartments.
  • each sub-compartment is in fluid communication with an environment outside the sub-compartment.
  • each sub-compartment comprises a wall that allows passage of one or more substances into and/or out of the sub-compartment.
  • the wall or a portion thereof comprises a perforated two-dimensional material, a polymer, a hydrogel, or some other means of allowing passage of one or more substance into and/or out of the sub-compartment.
  • an enclosure is subdivided into two sub-compartments separated from each other at least in part by perforated two-dimensional material, such that the two sub-compartments are in direct fluid communication with each other through holes in the two-dimensional material.
  • the enclosure is subdivided into two sub-compartments each comprising two-dimensional material which sub- compartments are in direct fluid communication with each other through holes in the two- dimensional material and only one of the sub-compartments is in direct fluid communication with an environment external to the enclosure.
  • the enclosure is subdivided into two sub-compartments each comprising two-dimensional material which sub- compartments are in direct fluid communication with each other through holes in the two- dimensional material and both of the sub-compartments are also in direct fluid communication with an environment external to the enclosure.
  • the enclosure has an inner sub-compartment and an outer sub- compartment each comprising a perforated two-dimensional material, wherein the inner sub- compartment is entirely enclosed within the outer sub-compartment, the inner and outer compartments are in direct fluid communication with each other through holes in the two- dimensional material and the inner sub-compartment is not in direct fluid communication with an environment external to the enclosure.
  • an enclosure has a plurality of sub-compartments each comprising a two-dimensional material
  • the sub-compartments are nested one within the other, each of which sub-compartments is in direct fluid communication through holes in two- dimensional material with the sub-compartment(s) to which it is adjacent, the outermost sub- compartment in direct fluid communication with an environment external to the enclosure, the remaining plurality of sub-compartments not in direct fluid communication with an environment external to the enclosure.
  • a sub-compartment can have any shape or size. In some embodiments, 2 or 3 sub-compartments are present.
  • enclosure sub- compartments are illustrated in Figures 61 A-61E.
  • Figure 61 A a nested configuration is illustrated, such that sub-compartment B completely contains a smaller sub-compartment A, and substances in the centermost enclosure A can pass into the main enclosure B, and potentially react with or within the main compartment during ingress and egress therefrom.
  • one or more substances in A can pass into B and one or more substances in A can be retained in A and not enter B.
  • Two sub-compartments in which one or more substances can pass directly between the sub-compartments are said to be in direct fluid communication.
  • Passage between sub-compartments and between the enclosure and the external environment can be via holes of a perforated two-dimensional material.
  • the barrier e.g., a membrane
  • the barrier between compartment A and B can be permeable to all substances in A or to certain substances in A (i.e., selective permeability).
  • the barrier between B and the external environment can be permeable to all substances in B or selectively permeable to certain substances in B.
  • sub-compartment A is in direct fluid communication with sub-compartment B which in turn is in direct fluid communication with the external environment.
  • Compartment A in this nested configuration is in indirect fluid communication with the external environment via intermediate passage into sub-compartment B.
  • the two- dimensional materials employed in different sub-compartments of an enclosure can be the same or different materials and the perforations or hole sizes in the two-dimensional material of different sub-compartments can be the same or different.
  • the enclosure is bisected with an impermeable wall (e.g., formed of non-porous or non-permeable sealant) forming sub-compartments A and B, such that both sections have access to the egress location independently, but there is no direct or indirect passage of substances from A to B. (It will be appreciated, however, that substances exiting A or B can enter the other sub-compartment indirectly via the external environment.)
  • an impermeable wall e.g., formed of non-porous or non-permeable sealant
  • the main enclosure is again bisected into sub-compartments A and B, but with a perforated material forming the barrier between the sub-compartments.
  • Both sub- compartments not only have access to the egress location independently, but also can interact with one another, i.e. the sub-compartments are in direct fluid communication.
  • the barrier between sub-compartments A and B is selectively permeable, for example allowing at least one substance in A to pass into B, but not allowing the substances originating in B to pass to A.
  • the porosity of the barrier between sub-compartments e.g., sub- compartments A and B
  • Figure 6 ID illustrates an enclosure having three compartments.
  • the enclosure is illustrated with sub-compartment A being in fluid communication with sub-compartment B, which in turn is in fluid communication with sub-compartment C, which in turn is in fluid communication with the external environment.
  • Compartments A and B are not in fluid communication with the external environment, i.e. they are not in direct fluid communication with the external environment.
  • Adjacent sub-compartments A and B and adjacent sub- compartments B and C are each separated by a perforated two-dimensional material and are thus in direct fluid communication with each other.
  • Sub-compartment A is only in indirect fluid communication with compartment C and the external environment via sub-compartment B or B and C, respectively.
  • the boundaries, or at least a portion thereof, of the enclosure can be constructed from a two-dimensional material such that the thickness of the two- dimensional material is less than the diameter of the substance to be passed selectively across the two-dimensional material.
  • Figure 6 IE illustrates an enclosure having a single compartment (A) and no sub- compartments.
  • the compartment is in direct fluid communication with an environment external to the enclosure.
  • the presence of two or more sub-compartments containing the same substance(s) provides redundancy in function so that an enclosure can remain at least partially operable so long as at least one sub-compartment is not compromised.
  • the multiple physical embodiments for the enclosures and their uses can allow for various levels of interaction and scaled complexity of problems to be solved.
  • a single enclosure can provide drug elution for a given time period, or there can be multiple sizes of perforations to restrict or allow movement of distinct substances, each having a particular size.
  • Added complexity of the embodiments described herein with multiple sub- compartments can allow for interaction between compounds to catalyze or activate a secondary response (i.e., a "sense-response" paradigm).
  • a secondary response i.e., a "sense-response" paradigm.
  • exemplary compound A can undergo a constant diffusion into the body, or either after a given time or in the presence of a stimulus from the body.
  • exemplary compound A can activate exemplary compound B, or inactivate functionalization that otherwise blocks exemplary compound B from escaping.
  • binding interactions to produce the foregoing effects can be reversible or irreversible.
  • exemplary compound A can interact with chemical cascades produced outside the enclosure, and a metabolite subsequent to the interaction can release exemplary compound B (e.g., by inactivating functionalization).
  • exemplary compound B e.g., by inactivating functionalization.
  • source cells e.g., non-host; allogenic; xenogenic; autogenic; cadeaveric; stem cells, such as fully or partially differentiated stem cells
  • stem cells such as fully or partially differentiated stem cells
  • growth factors or hormones can be loaded in the enclosure to encourage vascularization (see Figure 65).
  • survival of cells within the enclosure can be improved as a result of bi-directional passage of nutrients and waste into and out of the enclosure.
  • the relative thinness of graphene can enable bi-directional passage across a wall (or portion thereof) of the enclosure in close proximity to blood vessels, particularly capillary blood vessels, and other cells.
  • using a graphene- based enclosure can provide differentiation over other solutions accomplishing the same effect because the graphene does not appreciably limit permeability; instead, the diffusion of molecules through the graphene apertures can limit the movement of a substance across the wall.
  • the perforations allow for zeroth order diffusion through the wall.
  • osmotic pumps can be used to transport substances across the wall.
  • natural delta pressures in the body influence passage of substances across the wall.
  • convective pressure influences passage of substances across the wall.
  • Figures 62A and 62B provide a schematic illustration of enclosures with a single compartment for immunoisolation (it will be appreciated that the enclosure can having a plurality of sub-compartments, for example, two or three sub-compartments).
  • the enclosure (6030) of Figure 62 A is shown as a cross-section formed by an inner sheet or layer (6031) comprising perforated two-dimensional material, such as a graphene-based material, and an outer sheet or layer (6032) of a substrate material (though in some embodiments, the inner layer comprises the substrate material, and the outer layer comprises the perforate two-dimensional material).
  • the substrate material can be porous, selectively permeable or non-porous, and/or and non- permeable.
  • Figure 62B provides an alternative cross-section of the enclosure of Figure 62 A, showing the space or cavity formed between a first composite layer (6032/6031) and a second composite layer (6032/6031) (in the figure, the cavity is depicted to contain roughly circular symbols, which can be, e.g., cells or any other substance) where a sealant 6034 is illustrated as sealing the edges of the composite layers.
  • seals at the edges of the composite layers can be formed employing physical methods, such as clamping, crimping, or with adhesives. Methods and materials for forming the seals at the edges are not particularly limiting.
  • the sealing material provides a non-porous and non-permeable seal or closure.
  • a portion of the enclosure is formed from a sealant, such as a silicone, epoxy, polyurethane or similar material.
  • the sealant is biocompatible. For instance, in some embodiments the seal does not span the entire length or width of the device.
  • the seal forms a complete loop around the cavity.
  • the seal is formed as a frame at a perimeter of a two-dimensional material.
  • the seal is positioned, at least in in part, interior to a perimeter of a two-dimensional material.
  • Some embodiments include methods for using graphene-based materials and/or other two-dimensional materials to transport, transfer, deliver, and/or allow passage of substances in or to a biological environment. Some embodiments comprise delivering substances to an environment external to the enclosure (e.g., a biological environment).
  • the substance positioned on the inside of the enclosure comprises one or more of atoms, molecules, viruses, bacteria, cells, particles and aggregates thereof.
  • the substance can include biological molecules, such as proteins, peptides, (e.g., insulin), nucleic acids, DNA, and/or RNA; pharmaceuticals; drugs; medicaments; therapeutics, including biologies and small molecule drugs; and combinations thereof.
  • At least a portion of the enclosure can be permeable to oxygen and nutrients sufficient for cell growth and maintenance, to waste produced by the cell (e.g., CO 2 ), and/or to metabolites produced by the cell (e.g., insulin).
  • at least a portion of the enclosure is permeable to signaling molecules, such as glucose.
  • at least a portion of the enclosure is permeable to growth factors produced by cells, such as VEGF.
  • the enclosure is not permeable to cells (such as immune cells), viruses, bacteria, antibodies, and/or complements of the immune system. Thus, in some embodiments, cells from the external environment cannot enter the enclosure and cells in the enclosure are retained.
  • the enclosure is permeable to desirable products, such as growth factors or hormones produced by the cells (see, e.g., Figures 74 and 75, illustrating some embodiments related to immunoisolation).
  • the cells within the enclosure can be immunoisolated (i.e., protected from an immune reaction).
  • the cells are yeast cells, bacterial cells, stem cells, mammalian cells, human cells, porcine cells, or a combination thereof.
  • an enclosure comprises a plurality of sub-compartments, with the cells being positioned within one or more sub-compartments.
  • the enclosure comprises a single compartment.
  • hole sizes in perforated two-dimensional materials useful for immunoisolation range in size from 1-50 nm, 1-40 nm, 1-30 nm, 1-25 nm, 1-17 nm, 1- 15 nm, 1-12 nm, 1-10 nm, 3-50 nm, 3-30 nm, 3-20 nm, 3-10 nm, or 3-5 nm. In some
  • the size of the holes is about 1 nm, about 3 nm about 5 nm, about 10 nm, about 15 nm, about 20 nm, about 30 nm, or about 50 nm.
  • Figures 63A-63C illustrate an exemplary method for forming an enclosure and introducing selected substances, for example cells, therein. The method is illustrated with use of a sealant for forming the enclosure.
  • a first composite layer or sheet can be formed by placing a sheet or layer of two-dimensional material, such as a sheet of graphene-based material or a sheet of graphene (6141), in contact with a substrate layer (6142). At least a portion of the substrate layer (6142) of the first composite can be porous or permeable. Pore size of the substrate layer can be larger than the holes or apertures in the two-dimensional material employed and can be tuned for the environment (e.g., body cavity).
  • a layer of sealant (6144), e.g., silicone, is applied on the sheet or layer of perforated two-dimensional material outlining a compartment of the enclosure wherein the sealant will form a non-permeable seal around a perimeter of the enclosure. Formation of a single compartment is illustrated in Figures 63 A-63C, however, it will be appreciated that multiple independent compartments within an enclosure can be formed by an analogous process.
  • a second composite layer formed in the same way as the first is then prepared and positioned with the sheet or layer of perforated two dimensional materials in contact with the sealant.
  • a sealant can be applied to a portion of a composite layer and the layer can be folded over in contact with the sealant to form an enclosure. A seal is then formed between the two composite layers.
  • an alternative enclosure can be formed by applying a sheet or layer of non-porous and non-permeable support material in contact with the sealant. In this case only a portion of the enclosure is porous and permeable.
  • Other methods for sealing the enclosure include ultrasonic welding. Sealed composite layers are illustrated in Figure 63B where it is shown that the sealed layers can be trimmed to size around the sealant to form the enclosure.
  • the enclosure formed is shown to have an external porous substrate layer 6142 with the sheet or layer of perforated two-dimensional material (6141) being positioned as an internal layer, with sealant 6144 around the perimeter of the enclosure.
  • cells or other substances that would be excluded from passage through the perforated two-dimensional sheet or layer can be introduced into the enclosure after it is formed by injection through the sealant layer. Any perforation formed by such injection can be sealed as needed.
  • substances e.g., cells
  • one or more ports can be provided for introducing substances into the enclosure.
  • a loading port can be provided within the sealed perimeter of the enclosure, and the loading port can be permanently or semipermanently sealed after introduction of one or more substances through the loading port.
  • an enclosure comprises perforated two-dimensional material encapsulating a substance, such that the substance is released to an environment external to the enclosure by passage through the holes in the perforated two-dimensional material.
  • the enclosure encapsulates two or more different substances.
  • not all of the different substances are released to an environment external to the enclosure. In some embodiments, all of the different substances are released into an environment external to the enclosure. In some embodiments, different substances are released into an environment external to the enclosure at different rates. In some embodiments, different substances are released into an environment external to the enclosure at the same rates.
  • any enclosure herein at least a portion of the holes in the two-dimensional material of the enclosure are functionalized.
  • At least a portion of the two-dimensional material is conductive and a voltage can be applied to at least a portion of the conductive two-dimensional material.
  • the voltage can be an AC or DC voltage.
  • the voltage can be applied from a source external to the enclosure.
  • an enclosure device further comprises connectors and leads for application of a voltage from an external source to the two-dimensional material.
  • the conductive properties of graphene-based or other two-dimensional materials can allow for electrification to take place from an external source.
  • an AC or DC voltage can be applied to conductive two-dimensional materials (e.g., in a device such as an enclosure device).
  • the conductivity properties of graphene can provide additional gating to charged molecules or substances. Electrification can occur permanently or only a portion of the time to affect gating.
  • Directional gating of charged molecules can be directed not only through the pores (or restrict travel through pores), but also to the surface of the graphene to adsorb or bind and encourage growth, promote formation of a protective layer, or provide the basis or mechanism for other biochemical effects (e.g., on the body).
  • At least once wall, or portion thereof, of the enclosure allows for electrostatic control of charged species, for instance in nanofluidic or microfluidic systems.
  • the wall allows for control of charged species by varying the applied voltage, for instance in nanofluidic or microfluidic systems.
  • the wall can be tuned to manipulate ion passage at low and/or high ion concentrations.
  • the wall is an ion-selective membrane.
  • the wall comprises one or more voltage-gated ion channels, such as voltage-gated pores.
  • the wall mimics biological voltage-gated ion channels.
  • the wall is a solid- state membrane.
  • nanochannel or nanopore transistors can be used to manipulate ion passage.
  • the wall can be tuned using low or high applied voltages. In some embodiments, the wall allows high ionic flux. In some embodiments, the wall allows low ion flux. In some embodiments, pores in the wall modulates current of ions at low gate voltages and/or display high selectivity. In some embodiments, ion flux across the wall can be turned on or off at low applied voltages, such as ⁇ 500 mV. In some embodiments, ion flux across the wall can be turned on or off at biologically relevant ion concentrations, such as up to 1 M. In some embodiments, the applied voltage can modulate on species selectivity, e.g., cation or anion selectivity.
  • species selectivity e.g., cation or anion selectivity.
  • nanopores can be electrostatically controlled at low voltages and biologically relevant ion concentrations.
  • walls are used in separation and sensing technologies.
  • walls are used in water filtration, water desalination, water purification, osmosis, energy storage, microfluidic devices, nanofluidic devices, and/or therapeutic methods.
  • walls are used in immune-isolation (i.e., protecting substances from an immune reaction), timed drug release (e.g., sustained or delayed release), hemodialysis, and hemofiltration.
  • Some embodiments relate to methods of ultrafiltration, nanofiltration and/or microfiltration. Some embodiments comprise using gating to control release of substances. Some embodiments comprise using gating to allow for different substances to be released at different times. Some embodiments comprise allowing different substances to pass through the wall at different times, thus modulating when and how substances mix and interact with other substances in a specific order.
  • Some embodiments comprise a method comprising introducing an enclosure comprising perforated two-dimensional material into an environment, the enclosure containing at least one substance; and releasing at least a portion of the at least one substance through the holes of the two-dimensional material to the environment external to the enclosure.
  • the enclosure contains cells which are not released from the enclosure and the at least one substance, a portion of which is released, is a substance generated by the cells in the enclosure.
  • Some embodiments comprise a method comprising introducing an enclosure comprising perforated two-dimensional material to an environment, the enclosure containing at least one first substance; and allowing migration of other substances from the environment into the enclosure.
  • the first substance is cells, and other substances include nutrients and/or oxygen.
  • a composite structure comprises perforated two-dimensional material and a first fibrous layer comprising a plurality of polymer filaments affixed to a surface of the two-dimensional material; wherein the composite structure is substantially planar.
  • the perforated two-dimensional material has a second fibrous layer affixed to a surface of the two-dimensional material opposite the first fibrous layer.
  • the average pore size of the first fibrous layer is different from the average pore size of the second fibrous layer.
  • the first and/or second fibrous layer comprises an additive selected from the group consisting of pharmaceuticals, cells, growth factors, clotting factors, blood thinners, immunosuppressants, antimicrobial agents, hormones, antibodies, minerals, nutrients and combinations thereof.
  • the additive selected from the group consisting of pharmaceuticals, cells, growth factors, clotting factors, blood thinners, immunosuppressants, antimicrobial agents, hormones, antibodies, minerals, nutrients and combinations thereof.
  • substantially planar composite structure is flexible. In some embodiments, the substantially planar composite structure is rigid. In some embodiments, multiple composite structures are combined to form a pouch-like enclosure. Such planar composite structures can be useful, for example, as appliques for wound healing. The composite structures can also be used, for example, as a component of an adhesive bandage.
  • enclosures represent a disruptive technology for state of the art vehicle and other devices, such that these vehicles and devices to be used in new ways.
  • cell line developments, therapeutic releasing agents, and sensing paradigms e.g., MRSw's, MR-based magnetic relaxation switches, see; Koh et al. (2008) Ang. Chem. Int'l Ed. Engl., 47(22) 4119-4121
  • MRSw's MR-based magnetic relaxation switches
  • enclosures can be used in non-therapeutic applications, such as in dosing probiotics in dairy products.
  • two-dimensional materials are atomically thin, with thickness ranging from single-layer sub-nanometer thickness to a few nanometers.
  • Two-dimensional materials include metal chalogenides (e.g., transition metal dichalogenides), transition metal oxides, hexagonal boron nitride, graphene, silicene and germanene (see: Xu et al. (2013)
  • the two-dimensional material comprises a graphene-based material.
  • Graphene represents a form of carbon in which the carbon atoms reside within a single atomically thin sheet or a few layered sheets (e.g., about 20 or less) of fused six- membered rings forming an extended sp 2 -hybridized carbon planar lattice.
  • Graphene-based materials include, but are not limited to, single layer graphene, multilayer graphene or interconnected single or multilayer graphene domains and combinations thereof.
  • graphene-based materials also include materials which have been formed by stacking single or multilayer graphene sheets.
  • multilayer graphene includes 2 to 20 layers, 2 to 10 layers or 2 to 5 layers.
  • layers of multilayered graphene are stacked, but are less ordered in the z direction (perpendicular to the basal plane) than a thin graphite crystal.
  • a sheet of graphene-based material may be a sheet of single or multilayer graphene or a sheet comprising a plurality of interconnected single or multilayer graphene domains, which may be observed in any known manner such as using for example small angle electron diffraction, transmission electron microscopy, etc..
  • the multilayer graphene domains have 2 to 5 layers or 2 to 10 layers.
  • a domain refers to a region of a material where atoms are substantially uniformly ordered into a crystal lattice. A domain is uniform within its boundaries, but may be different from a neighboring region. For example, a single crystalline material has a single domain of ordered atoms.
  • At least some of the graphene domains are nanocrystals, having domain size from 1 to 100 nm or 10-100 nm. In some embodiments, at least some of the graphene domains have a domain size greater than from 100 nm to 1 cm, or from 100 nm to 1 micron, or from 200 nm to 800 nm, or from 300 nm to 500 nm. In some embodiments, a domain of multilayer graphene may overlap a neighboring domain. Grain boundaries formed by crystallographic defects at edges of each domain may differentiate between neighboring crystal lattices.
  • a first crystal lattice may be rotated relative to a second crystal lattice, by rotation about an axis perpendicular to the plane of a sheet, such that the two lattices differ in crystal lattice orientation.
  • the sheet of graphene-based material is a sheet of single or multilayer graphene or a combination thereof.
  • the sheet of graphene-based material is a sheet comprising a plurality of interconnected single or multilayer graphene domains.
  • the interconnected domains are covalently bonded together to form the sheet.
  • the sheet is polycrystalline.
  • the thickness of the sheet of graphene-based material is from 0.3 to 10 nm, 0.34 to 10 nm, from 0.34 to 5 nm, or from 0.34 to 3 nm. In some embodiments, the thickness includes both single layer graphene and the non-graphenic carbon.
  • a sheet of graphene-based material comprises intrinsic or native defects.
  • Intrinsic or native defects may result from preparation of the graphene-based material in contrast to perforations which are selectively introduced into a sheet of graphene- based material or a sheet of graphene.
  • Such intrinsic or native defects may include, but are not limited to, lattice anomalies, pores, tears, cracks or wrinkles.
  • Lattice anomalies can include, but are not limited to, carbon rings with other than 6 members (e.g. 5, 7 or 9 membered rings), vacancies, interstitial defects (including incorporation of non-carbon atoms in the lattice), and grain boundaries.
  • graphene is the dominant material in a graphene-based material.
  • a graphene-based material may comprise at least 20% graphene, at least 30%) graphene, or at least 40% graphene, or at least 50% graphene, or at least 60%> graphene, or at least 70% graphene, or at least 80% graphene, or at least 90% graphene, or at least 95% graphene.
  • a graphene-based material comprises a range of graphene selected from 30% to 95%, or from 40% to 80% from 50% to 70%, from 60% to 95% or from 75%) to 100%).
  • the amount of graphene in the graphene-based material is quantified as an atomic percentage utilizing known methods including scanning transmission electron microscope examination, or alternatively if STEM or TEM is ineffective another similar measurement technique.
  • a sheet of graphene-based material further comprises non- graphenic carbon-based material located on at least one surface of the sheet of graphene-based material.
  • the sheet is exemplified by two base surfaces (e.g. top and bottom faces of the sheet, opposing faces) and side faces (e.g. the side faces of the sheet).
  • the "bottom" face of the sheet is that face which contacted the substrate during growth of the sheet and the "free" face of the sheet opposite the "bottom” face.
  • non-graphenic carbon-based material may be located on one or both base surfaces of the sheet (e.g. the substrate side of the sheet and/or the free surface of the sheet).
  • the sheet of graphene-based material includes a small amount of one or more other materials on the surface, such as, but not limited to, one or more dust particles or similar contaminants.
  • the amount of non-graphenic carbon-based material is less than the amount of graphene. In some further embodiments, the amount of non-graphenic carbon material is three to five times the amount of graphene; this is measured in terms of mass. In some additional embodiments, the non-graphenic carbon material is characterized by a percentage by mass of said graphene-based material selected from the range of 0% to 80%. In some embodiments, the surface coverage of the sheet of non-graphenic carbon-based material is greater than zero and less than 80%, from 5% to 80%, from 10% to 80%, from 5% to 50% or from 10%) to 50%. This surface coverage may be measured with transmission electron microscopy, which gives a projection.
  • the amount of graphene in the graphene-based material is from 60% to 95% or from 75% to 100%.
  • the amount of graphene in the graphene-based material is measured as an atomic percentage utilizing known methods preferentially using transmission electron microscope examination, or alternatively if STEM is ineffective using an atomic force microscope.
  • the non-graphenic carbon-based material does not possess long range order and is classified as amorphous.
  • the non-graphenic carbon-based material further comprises elements other than carbon and/or hydrocarbons.
  • non-carbon elements which may be incorporated in the non-graphenic carbon include hydrogen, oxygen, silicon, copper, and iron.
  • the non-graphenic carbon-based material comprises hydrocarbons.
  • carbon is the dominant material in non-graphenic carbon-based material.
  • a non-graphenic carbon-based material in some embodiments comprises at least 30% carbon, or at least 40% carbon, or at least 50% carbon, or at least 60% carbon, or at least 70% carbon, or at least 80% carbon, or at least 90% carbon, or at least 95% carbon.
  • a non-graphenic carbon-based material comprises a range of carbon selected from 30% to 95%, or from 40% to 80%), or from 50% to 70%.
  • the amount of carbon in the non-graphenic carbon-based material is measured as an atomic percentage utilizing known methods preferentially using transmission electron microscope examination, or alternatively if STEM is ineffective using atomic force microscope.
  • Perforation techniques suitable for use in perforating the graphene-based materials may include described herein ion-based perforation methods and UV-oxygen based methods.
  • Ion-based perforation methods include methods in which the graphene-based material is irradiated with a directional source of ions.
  • the ion source is collimated.
  • the ion source is a broad beam or flood source.
  • a broad field or flood ion source can provide an ion flux which is significantly reduced compared to a focused ion beam.
  • the ion source inducing perforation of the graphene or other two- dimensional material is considered to provide a broad ion field, also commonly referred to as an ion flood source.
  • the ion flood source does not include focusing lenses.
  • the ion source is operated at less than atmospheric pressure, such as at 10- 3 to 10 -5 torr or 10 -4 to 10 -6 torr.
  • the environment also contains background amounts (e.g. on the order of 10 -5 torr) of oxygen (O 2 ), nitrogen (N 2 ) or carbon dioxide (CO 2 ).
  • the ion beam may be perpendicular to the surface of the layer(s) of the material (incidence angle of 0 degrees) or the incidence angle may be from 0 to 45 degrees, 0 to 20 degrees, 0 to 15 degrees or 0 to 10 degrees.
  • exposure to ions does not include exposure to plasma.
  • UV-oxygen based perforation methods include methods in which the graphene-based material is simultaneously exposed to ultraviolet (UV) light and an oxygen containing gas Ozone may be generated by exposure of an oxygen containing gas such as oxygen or air to the UV light. Ozone may also be supplied by an ozone generator device.
  • the UV-oxygen based perforation method further includes exposure of the graphene-based material to atomic oxygen. Suitable wavelengths of UV light include, but are not limited to wavelengths below 300 nm or from 150 nm to 300 nm. In some embodiments, the intensity from 10 to 100 mW/cm 2 at 6mm distance or 100 to 1000 mW/cm 2 at 6mm distance.
  • suitable light is emitted by mercury discharge lamps (e.g. about 185 nm and 254 nm).
  • UV/oxygen cleaning is performed at room temperature or at a temperature greater than room temperature.
  • UV/oxygen cleaning is performed at atmospheric pressure (e.g. 1 atm) or under vacuum.
  • Perforations are sized as described herein to provide desired selective permeability of a species (atom, molecule, protein, virus, cell, etc.) for a given application.
  • permeability relates to the propensity of a porous material or a perforated two-dimensional material to allow passage (or transport) of one or more species more readily or faster than other species. Selective permeability allows separation of species which exhibit different passage or transport rates. In two-dimensional materials selective permeability correlates to the dimension or size (e.g., diameter) of apertures and the relative effective size of the species. Selective permeability of the perforations in two-dimensional materials such as graphene-based materials can also depend on functionalization of perforations (if any) and the specific species. Separation or passage of two or more species in a mixture includes a change in the ratio(s) (weight or molar ratio) of the two or more species in the mixture during and after passage of the mixture through a perforated two-dimensional material.
  • the characteristic size of the perforation is from 0.3 to 10 nm, from 1 to 10 nm, from 5 to 10 nm, from 5 to 20 nm, from 10 nm to 50 nm, from 50 nm to 100 nm, from 50 nm to 150 nm, from 100 nm to 200 nm, or from 100 nm to 500 nm.
  • the average pore size is within the specified range. In some embodiments, 70% to 99%, 80% to 99%, 85% to 99% or 90 to 99% of the perforations in a sheet or layer fall within a specified range, but other pores fall outside the specified range.
  • Nanomaterials in which pores are intentionally created may be referred to as perforated graphene, perforated graphene-based materials or perforated two-dimensional materials, and the like.
  • Perforated graphene-based materials include materials in which non- carbon atoms have been incorporated at the edges of the pores.
  • Pore features and other material features may be characterized in a variety of manners including in relation to size, area, domains, periodicity, coefficient of variation, etc. For instance, the size of a pore may be assessed through quantitative image analysis utilizing images preferentially obtained through transmission electron microscopy, and if TEM is ineffective, through atomic force microscopy, and if AFM is ineffective, through scanning electron microscopy, as for example presented in Figs.
  • the boundary of the presence and absence of material identifies the contour of a pore.
  • the size of a pore may be determined by shape fitting of an expected species against the imaged pore contour where the size measurement is characterized by smallest dimension unless otherwise specified.
  • the shape may be round or oval.
  • the round shape exhibits a constant and smallest dimension equal to its diameter.
  • the width of an oval is its smallest dimension. The diameter and width measurements of the shape fitting in these instances provide the size measurement, unless specified otherwise.
  • Each pore size of a test sample may be measured to determine a distribution of pore sizes within the test sample. Other parameters may also be measured such as area, domain, periodicity, coefficient of variation, etc.
  • Multiple test samples may be taken of a larger membrane to determine that the consistency of the results properly characterizes the whole membrane. In such instance, the results may be confirmed by testing the performance of the membrane with test species. For example, if measurements indicate that certain sizes of species should be restrained from transport across the membrane, a performance test provides verification with test species. Alternatively, the performance test may be utilized as an indicator that the pore measurements will determine a concordant pore size, area, domains, periodicity, coefficient of variation, etc.

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Abstract

Les présents modes de réalisation portent d'une manière générale sur des matériaux bi-dimensionnels, tels que le graphène ainsi que des polymères à base de lamelles de graphène, et leurs procédés d'utilisation et de production.
PCT/US2016/027637 2015-08-05 2016-04-14 Matériaux bi-dimensionnels et leurs utilisations WO2017023380A1 (fr)

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US201562201539P 2015-08-05 2015-08-05
US201562201527P 2015-08-05 2015-08-05
US62/201,527 2015-08-05
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US201562202056P 2015-08-06 2015-08-06
US201562202122P 2015-08-06 2015-08-06
US62/202,056 2015-08-06
US62/202,122 2015-08-06
US15/099,276 US20170037356A1 (en) 2015-08-06 2016-04-14 Biologically-relevant selective enclosures for promoting growth and vascularization
US15/099,447 2016-04-14
US15/099,289 US10376845B2 (en) 2016-04-14 2016-04-14 Membranes with tunable selectivity
US15/099,420 US10118130B2 (en) 2016-04-14 2016-04-14 Two-dimensional membrane structures having flow passages
US15/099,056 2016-04-14
US15/099,420 2016-04-14
US15/099,295 US20170298191A1 (en) 2016-04-14 2016-04-14 Graphene platelet-based polymers and uses thereof
US15/099,464 2016-04-14
US15/099,464 US10017852B2 (en) 2016-04-14 2016-04-14 Method for treating graphene sheets for large-scale transfer using free-float method
US15/099,193 US20170035943A1 (en) 2015-08-06 2016-04-14 Implantable graphene membranes with low cytotoxicity
US15/099,099 US10696554B2 (en) 2015-08-06 2016-04-14 Nanoparticle modification and perforation of graphene
US15/099,482 2016-04-14
US15/099,304 US10980919B2 (en) 2016-04-14 2016-04-14 Methods for in vivo and in vitro use of graphene and other two-dimensional materials
US15/099,304 2016-04-14
US15/099,269 2016-04-14
US15/099,056 US10203295B2 (en) 2016-04-14 2016-04-14 Methods for in situ monitoring and control of defect formation or healing
US15/099,276 2016-04-14
US15/099,193 2016-04-14
US15/099,410 US10213746B2 (en) 2016-04-14 2016-04-14 Selective interfacial mitigation of graphene defects
US15/099,447 US20170296982A1 (en) 2016-04-14 2016-04-14 Healing of thin graphenic-based membranes via charged particle irradiation
US15/099,239 2016-04-14
US15/099,482 US20170296972A1 (en) 2016-04-14 2016-04-14 Method for making two-dimensional materials and composite membranes thereof having size-selective perforations
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US15/099,239 US20170036911A1 (en) 2015-08-05 2016-04-14 Perforated sheets of graphene-based material
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017199247A1 (fr) 2016-05-16 2017-11-23 B.G. Negev Technologies And Applications Ltd., At Ben-Gurion University Espaceur antibiofilm et antimicrobien pour membrane fonctionnelle
CN112110411A (zh) * 2019-06-19 2020-12-22 中国科学院物理研究所 一种制备悬空的层状金属硫属化合物的方法
WO2022086402A1 (fr) * 2020-10-19 2022-04-28 Sht Smart High-Tech Ab Film composite thermoconducteur renforcé par un film de graphène, son procédé de préparation et son utilisation

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012125770A2 (fr) 2011-03-15 2012-09-20 President And Fellows Of Harvard College Fabrication commandée de nano-pores dans des matériaux semi-conducteurs nanométriques
US20130240355A1 (en) 2012-03-16 2013-09-19 Lockheed Martin Corporation Functionalization of graphene holes for deionization
US20130270188A1 (en) 2012-03-15 2013-10-17 Massachusetts Institute Of Technology Graphene based filter
US20140030482A1 (en) 2012-07-25 2014-01-30 Seth Adrian Miller Graphene membrane repair
US20140199777A2 (en) 2012-06-12 2014-07-17 University Of Dayton Graphene oxide filters and methods of use
US20140272286A1 (en) 2013-03-13 2014-09-18 Lockheed Martin Corporation Nanoporous membranes and methods for making the same
WO2014168629A1 (fr) 2013-04-12 2014-10-16 General Electric Company Membranes comprenant du graphène
WO2015116946A1 (fr) 2014-01-31 2015-08-06 Lockheed Martin Corporation Perforation de matériaux bidimensionnels à l'aide d'un large champ ionique
WO2016036888A1 (fr) 2014-09-02 2016-03-10 Lockheed Martin Corporation Membranes d'hémodialyse et d'hémofiltration basées sur un matériau membranaire bidimensionnel et procédés employant ces dernières
EP2995368A1 (fr) 2014-09-12 2016-03-16 Korea Institute Of Machinery & Materials Procédé de fabrication de nanotrous et filtre fabriqué par ce dernier

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012125770A2 (fr) 2011-03-15 2012-09-20 President And Fellows Of Harvard College Fabrication commandée de nano-pores dans des matériaux semi-conducteurs nanométriques
US20130270188A1 (en) 2012-03-15 2013-10-17 Massachusetts Institute Of Technology Graphene based filter
US20130240355A1 (en) 2012-03-16 2013-09-19 Lockheed Martin Corporation Functionalization of graphene holes for deionization
US20140199777A2 (en) 2012-06-12 2014-07-17 University Of Dayton Graphene oxide filters and methods of use
US20140030482A1 (en) 2012-07-25 2014-01-30 Seth Adrian Miller Graphene membrane repair
US20140272286A1 (en) 2013-03-13 2014-09-18 Lockheed Martin Corporation Nanoporous membranes and methods for making the same
WO2014168629A1 (fr) 2013-04-12 2014-10-16 General Electric Company Membranes comprenant du graphène
WO2015116946A1 (fr) 2014-01-31 2015-08-06 Lockheed Martin Corporation Perforation de matériaux bidimensionnels à l'aide d'un large champ ionique
WO2016036888A1 (fr) 2014-09-02 2016-03-10 Lockheed Martin Corporation Membranes d'hémodialyse et d'hémofiltration basées sur un matériau membranaire bidimensionnel et procédés employant ces dernières
EP2995368A1 (fr) 2014-09-12 2016-03-16 Korea Institute Of Machinery & Materials Procédé de fabrication de nanotrous et filtre fabriqué par ce dernier

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
KYOUNG HWAN KIM ET AL.: "High quality reduced graphene oxide through repairing with multi-layered graphene ball nanostructures", SCIENTIFIC REPORTS, vol. 3, no. 1, 19 November 2013 (2013-11-19)
LENA A. L. TANG ET AL.: "Highly Wrinkled Cross-Linked Graphene Oxide Membranes for Biological and Charge-Storage Applications", SMALL, vol. 8, no. 3, 1 January 2012 (2012-01-01), pages 423 - 431, XP055432926, ISSN: 1613-6810, doi:10.1002/smll.201101690
See also references of EP3331588A4

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017199247A1 (fr) 2016-05-16 2017-11-23 B.G. Negev Technologies And Applications Ltd., At Ben-Gurion University Espaceur antibiofilm et antimicrobien pour membrane fonctionnelle
EP3458420A4 (fr) * 2016-05-16 2019-04-17 B.G. Negev Technologies & Applications Ltd., at Ben-Gurion University Espaceur antibiofilm et antimicrobien pour membrane fonctionnelle
EP3889115A1 (fr) * 2016-05-16 2021-10-06 B.G. Negev Technologies and Applications Ltd., at Ben-Gurion University Méthode et appareil antibiofilm et antimicrobien
CN112110411A (zh) * 2019-06-19 2020-12-22 中国科学院物理研究所 一种制备悬空的层状金属硫属化合物的方法
CN112110411B (zh) * 2019-06-19 2023-06-06 中国科学院物理研究所 一种制备悬空的层状金属硫属化合物的方法
WO2022086402A1 (fr) * 2020-10-19 2022-04-28 Sht Smart High-Tech Ab Film composite thermoconducteur renforcé par un film de graphène, son procédé de préparation et son utilisation

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