Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
  • C04B35/52—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite
  • C04B35/522—Graphite
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
  • B01J20/20—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising free carbon; comprising carbon obtained by carbonising processes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
  • B01J20/28002—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their physical properties
  • B01J20/28011—Other properties, e.g. density, crush strength
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
  • B01J20/28014—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their form
  • B01J20/28042—Shaped bodies; Monolithic structures
  • B01J20/28045—Honeycomb or cellular structures; Solid foams or sponges
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
  • B01J20/28054—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
  • B01J20/28057—Surface area, e.g. B.E.T specific surface area
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/3078—Thermal treatment, e.g. calcining or pyrolizing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/32—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating
  • B01J20/3202—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating characterised by the carrier, support or substrate used for impregnation or coating
  • B01J20/3204—Inorganic carriers, supports or substrates
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/32—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating
  • B01J20/3231—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating characterised by the coating or impregnating layer
  • B01J20/3234—Inorganic material layers
  • B01J20/324—Inorganic material layers containing free carbon, e.g. activated carbon
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
  • C04B35/52—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite
  • C04B35/524—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite obtained from polymer precursors, e.g. glass-like carbon material
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
  • C04B35/62605—Treating the starting powders individually or as mixtures
  • C04B35/6261—Milling
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B38/00—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
  • C04B38/0022—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof obtained by a chemical conversion or reaction other than those relating to the setting or hardening of cement-like material or to the formation of a sol or a gel, e.g. by carbonising or pyrolysing preformed cellular materials based on polymers, organo-metallic or organo-silicon precursors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y40/00—Manufacture or treatment of nanostructures
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
  • C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
  • C04B2111/00793—Uses not provided for elsewhere in C04B2111/00 as filters or diaphragms
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
  • C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
  • C04B2111/00793—Uses not provided for elsewhere in C04B2111/00 as filters or diaphragms
  • C04B2111/00801—Membranes; Diaphragms
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
  • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
  • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
  • C04B2235/42—Non metallic elements added as constituents or additives, e.g. sulfur, phosphor, selenium or tellurium
  • C04B2235/422—Carbon
  • C04B2235/425—Graphite
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
  • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
  • C04B2235/50—Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
  • C04B2235/52—Constituents or additives characterised by their shapes
  • C04B2235/5292—Flakes, platelets or plates
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
  • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
  • C04B2235/72—Products characterised by the absence or the low content of specific components, e.g. alkali metal free alumina ceramics
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
  • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
  • C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance

Definitions

• the present invention relates generally to the field of carbon/graphite foams and, more particularly, to a new form of porous graphitic material herein referred to as an integral 3D graphene-carbon hybrid foam, a process for producing same, products containing same, and a method of operating the product.
• Carbon is known to have five unique crystalline structures, including diamond, fullerene (0-D nano graphitic material), carbon nano-tube or carbon nano-fiber (1-D nano graphitic material), graphene (2-D nano graphitic material), and graphite (3-D graphitic material).
• the carbon nano-tube (CNT) refers to a tubular structure grown with a single wall or multi-wall.
• Carbon nano-tubes (CNTs) and carbon nano-fibers (CNFs) have a diameter on the order of a few nanometers to a few hundred nanometers.
• Their longitudinal, hollow structures impart unique mechanical, electrical and chemical properties to the material.
• the CNT or CNF is a one- dimensional nano carbon or 1-D nano graphite material.
• a single-layer graphene sheet is composed of carbon atoms occupying a two-dimensional hexagonal lattice.
• Multi-layer graphene is a platelet composed of more than one graphene plane.
• Individual single-layer graphene sheets and multi-layer graphene platelets are herein collectively called nano graphene platelets (NGPs) or graphene materials.
• NGPs include pristine graphene (essentially 99% of carbon atoms), slightly oxidized graphene ( ⁇ 5% by weight of oxygen), graphene oxide (> 5% by weight of oxygen), slightly fluorinated graphene ( ⁇ 5% by weight of fluorine), graphene fluoride ((> 5% by weight of fluorine), other halogenated graphene, and chemically functionalized graphene.
• NGPs have been found to have a range of unusual physical, chemical, and mechanical properties. For instance, graphene was found to exhibit thejiighest intrinsic strength and highest thermal conductivity of all existing materials. Although practical electronic device applications for graphene (e.g., replacing Si as a backbone in a transistor) are not envisioned to occur within the next 5-10 years, its application as a nano filler in a composite material and an electrode material in energy storage devices is imminent. The availability of processable graphene sheets in large quantities is essential to the success in exploiting composite, energy, and other applications for graphene.
• the first approach (FIG. 1) entails treating natural graphite powder with an intercalant and an oxidant (e.g., concentrated sulfuric acid and nitric acid, respectively) to obtain a graphite intercalation compound (GIC) or, actually, graphite oxide (GO).
• GIC graphite intercalation compound
• GO graphite oxide
• the inter- graphene spacing is increased to a value typically greater than 0.6 nm. This is the first expansion stage experienced by the graphite material during this chemical route.
• the obtained GIC or GO is then subjected to further expansion (often referred to as exfoliation) using either a thermal shock exposure or a solution-based, ultrasonication-assisted graphene layer exfoliation approach.
• the GIC or GO is exposed to a high temperature (typically 800-l,050°C) for a short period of time (typically 15 to 60 seconds) to exfoliate or expand the GIC or GO for the formation of exfoliated or further expanded graphite, which is typically in the form of a "graphite worm" composed of graphite flakes that are still
• the expanded or exfoliated GO powder is dispersed in water or aqueous alcohol solution, which is subjected to ultrasonication. It is important to note that in these processes, ultrasonification is used after intercalation and oxidation of graphite (i.e., after first expansion) and typically after thermal shock exposure of the resulting GIC or GO (after second expansion).
• the GO powder dispersed in water is subjected to an ion exchange or lengthy purification procedure in such a manner that the repulsive forces between ions residing in the inter-planar spaces overcome the inter-graphene van der Waals forces, resulting in graphene layer separations.
• the process requires the use of large quantities of several undesirable chemicals, such as sulfuric acid, nitric acid, and potassium permanganate or sodium chlorate.
• the chemical treatment process requires a long intercalation and oxidation time, typically 5 hours to five days.
• the thermal exfoliation requires a high temperature (typically 800-l,200°C) and, hence, is a highly energy-intensive process.
• the resulting products are GO platelets that must undergo a further chemical reduction treatment to reduce the oxygen content.
• the electrical conductivity of GO platelets remains much lower than that of pristine graphene.
• the reduction procedure often involves the utilization of toxic chemicals, such as hydrazine.
• the quantity of intercalation solution retained on the flakes after draining may range from 20 to 150 parts of solution by weight per 100 parts by weight of graphite flakes (pph) and more typically about 50 to 120 pph.
• the residual intercalate species retained by the flakes decompose to produce various species of sulfuric and nitrous compounds (e.g., NO x and SO x ), which are undesirable.
• the effluents require expensive remediation procedures in order not to have an adverse environmental impact.
• the present invention was made to overcome the limitations or problems outlined above.
• Another process for producing graphene, in a thin film form is the catalytic chemical vapor deposition process.
• This catalytic CVD involves catalytic decomposition of hydrocarbon gas (e.g. C 2 H 4 ) on Ni or Cu surface to form single-layer or few-layer graphene.
• hydrocarbon gas e.g. C 2 H 4
• Ni or Cu being the catalyst, carbon atoms obtained via
• NGPs or graphene materials include discrete sheets/platelets of single-layer and multi-layer (typically less than 10 layers) pristine graphene, graphene oxide, reduced graphene oxide (RGO), graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, chemically functionalized graphene, doped graphene (e.g. doped by B or N).
• Pristine graphene has essentially 0% oxygen.
• RGO typically has an oxygen content of 0.001%-5% by weight.
• Graphene oxide (including RGO) can have 0.001%-50% by weight of oxygen.
• all the graphene materials have 0.001%-50% by weight of non-carbon elements (e.g. O, H, N, B, F, CI, Br, I, etc.). These materials are herein referred to as non-pristine graphene materials.
• non-carbon elements e.g. O, H, N, B, F, CI, Br, I, etc.
• non-pristine graphene materials e.g. O, H, N, B, F, CI, Br, I, etc.
• a foam or foamed material is composed of pores (or cells) and pore walls (a solid material).
• the pores can be interconnected to form an open-cell foam.
• a graphene foam is composed of pores and pore walls that contain a graphene material.
• the first method is the hydrothermal reduction of graphene oxide hydrogel that typically involves sealing graphene oxide (GO) aqueous suspension in a high-pressure autoclave and heating the GO suspension under a high pressure (tens or hundreds of atm) at a temperature typically in the range of 180-300°C for an extended period of time (typically 12-36 hours).
• a useful reference for this method is given here: Y. Xu, et al. "Self- Assembled Graphene Hydrogel via a One-Step Hydrothermal Process," ACS Nano 2010, 4, 4324-4330.
• the second method is based on a template-assisted catalytic CVD process, which involves CVD deposition of graphene on a sacrificial template (e.g. Ni foam).
• a sacrificial template e.g. Ni foam
• the graphene material conforms to the shape and dimensions of the Ni foam structure.
• the Ni foam is then etched away using an etching agent, leaving behind a monolith of graphene skeleton that is essentially an open-cell foam.
• Zongping Chen, et al. "Three-dimensional flexible and conductive interconnected graphene networks grown by chemical vapour deposition," Nature Materials, 10 (June 2011) 424-428.
• the third method of producing graphene foam also makes use of a sacrificial material
• Yet another object of the present invention is to provide (a) a pristine graphene-based hybrid foam that contains essentially all carbon only and preferably have a meso-scaled pore size range (2-50 nm); and (b) non-pristine graphene foams (graphene fluoride, graphene chloride, nitrogenated graphene, etc.) that contains at least 0.001% by weight (typically from 0.01% to 25%) by weight and most typically from 0.1%> to 20%>) of non-carbon elements that can be used for a broad array of applications.
• a pristine graphene-based hybrid foam that contains essentially all carbon only and preferably have a meso-scaled pore size range (2-50 nm
• non-pristine graphene foams graphene fluoride, graphene chloride, nitrogenated graphene, etc.
• Another object of the present invention is to provide products (e.g. devices) that contain a graphene-carbon foam of the present invention and methods of operating these products.
• the present invention provides a method of producing an integral 3D graphene-carbon hybrid foam directly from particles of a graphitic material and particles of a polymer. This method is stunningly simple. The method comprises:
• this consolidating step can be as simple as a compacting step that just packs graphene-coated or embedded particles into a desired shape
• step (c) includes operating a magnet to separate the impacting balls or media from the graphene-coated or graphene-embedded polymer particles.
• the solid polymer material particles can include plastic or rubber beads, pellets, spheres, wires, fibers, filaments, discs, ribbons, or rods, having a diameter or thickness from 10 nm to 10 mm. Preferably, the diameter or thickness is from 100 nm to 1 mm, and more preferably from 200 nm to 200 ⁇ .
• the solid polymer may be selected from solid particles of a thermoplastic, thermoset resin, rubber, semi-penetrating network polymer, penetrating network polymer, natural polymer, or a combination thereof. In an embodiment, the solid polymer is partially removed by melting, etching, or dissolving in a solvent prior to step (d).
• the graphitic material is selected from natural graphite, synthetic graphite, highly oriented pyrolytic graphite, graphite fiber, graphitic nano-fiber, graphite fluoride, oxidized graphite, chemically modified graphite, exfoliated graphite, recompressed exfoliated graphite, expanded graphite, meso-carbon micro-bead, or a combination thereof.
• the graphitic material contains a non-intercalated and non-oxidized graphitic material that has never been previously exposed to a chemical or oxidation treatment prior to the mixing step (a).
• the energy impacting apparatus can be a vibratory ball mill, planetary ball mill, high energy mill, basket mill, agitator ball mill, cryo ball mill, micro ball mill, tumbler ball mill, continuous ball mill, stirred ball mill, pressurized ball mill, freezer mill, vibratory sieve, bead mill, nano bead mill, ultrasonic homogenizer mill, centrifugal planetary mixer, vacuum ball mill, or resonant acoustic mixer.
• the carbon yield is the weight percentage of a polymer structure that is converted by heat to a solid carbon phase, instead of becoming part of a volatile gas.
• the high carbon-yield polymer may be selected from phenolic resin, poly furfuryl alcohol, polyacrylonitrile, polyimide, polyamide, polyoxadiazole, polybenzoxazole, polybenzobisoxazole, polythiazole,
• polybenzothiazole polybenzobisthiazole, poly(p-phenylene vinylene), polybenzimidazole, polybenzobisimidazole, a copolymer thereof, a polymer blend thereof, or a combination thereof.
• the polymer can contain a low carbon-yield polymer selected from polyethylene, polypropylene, polybutylene, polyvinyl chloride, polycarbonate, acrylonitrile-butadiene (ABS), polyester, polyvinyl alcohol, poly vinylidiene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyphenylene oxide (PPO), poly methyl methacrylate (PMMA), a copolymer thereof, a polymer blend thereof, or a combination thereof.
• a low carbon-yield polymer selected from polyethylene, polypropylene, polybutylene, polyvinyl chloride, polycarbonate, acrylonitrile-butadiene (ABS), polyester, polyvinyl alcohol, poly vinylidiene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyphenylene oxide (PPO), poly methyl methacrylate (PMMA), a copolymer thereof, a polymer blend thereof, or a combination thereof
• these polymers when heated at a temperature of 300-2,500°C, are converted into a carbon material, which is preferentially nucleated near graphene sheet edges.
• a carbon material serves to bridge the gaps between graphene sheets, forming interconnected electron-conducting pathways.
• the resulting graphene-carbon hybrid foam is composed of integral 3D network of carbon-bonded graphene sheets, allowing continuous transport of electrons and phonons (quantized lattice vibrations) between graphene sheets or domains without interruptions.
• the graphene-bonding carbon phase can get graphitized provided that the carbon phase is "soft carbon" or graphitizable. In such a situation, both the electric conductivity and thermal conductivity are further increased.
• the step of pyrolyzing includes carbonizing the polymer at a temperature from 200°C to 2,500°C to obtain carbon-bonded graphene sheets.
• the carbon-bonded graphene sheets can be subsequently graphitized at a temperature from 2,500°C to 3,200°C to obtain graphite-bonded graphene sheets.
• pyrolyzation of a polymer tends to lead to the formation of pores in the resulting polymeric carbon phase due to the evolution of those volatile gas molecules such as C0 2 and H 2 0.
• such pores also have a high tendency to get collapsed if the polymer is not constrained when being carbonized.
• the graphene sheets wrapped around a polymer particle are capable of constraining the carbon pore walls from being shrunk and collapsed, while some carbon species also permeate to the gaps between graphene sheets where these species bond the graphene sheets together.
• the pore sizes and pore volume (porosity level) of the resulting 3D integral graphene foam depend upon the starting polymer size and the carbon yield of the polymer and, to a lesser extent, on the pyrolyzation temperature.
• the consolidating step includes compacting a mass of these graphene-coated polymer particles into a desired shape. For instance, by squeezing and compressing the mass of graphene-coated particles into a mold cavity one can readily form a compact green body. One can rapidly heat and melt the polymer, slightly compress the green body to slightly fuse the polymer particles together by heat, and rapidly cool to solidify the body. This consolidated body is then subjected to a pyrolysis treatment (polymer carbonization and, optionally, graphitization).
• a pyrolysis treatment polymer carbonization and, optionally, graphitization
• the consolidating step includes melting the polymer particles to form a polymer melt mixture with graphene sheets dispersed therein, forming the polymer melt mixture into a desired shape and solidifying the shape into a graphene-polymer composite structure.
• shape can be a rod, film (thin or thick film, wide or narrow, single sheets or in a roll), fiber (short filament or continuous long filament), plate, ingot, any regular shape or odd shape. This graphene-polymer composite shape is then pyrolyzed
• the consolidating step may include dissolving the polymer particles in a solvent to form a polymer solution mixture with graphene sheets dispersed therein, forming the polymer solution mixture into a desired shape, and removing the solvent to solidify the shape into the graphene-polymer composite structure. This composite structure is then pyrolyzed to form a porous structure.
• the consolidating step may include melting the polymer particles to form a polymer melt mixture with graphene sheets dispersed therein and extruding the mixture into a rod form or sheet form, spinning the mixture into a fiber form, spraying the mixture into a powder form, or casting the mixture into an ingot form.
• the consolidating step includes dissolving the polymer particles in a solvent to form a polymer solution mixture with graphene sheets dispersed therein and extruding the solution mixture into a rod form or sheet form, spinning the solution mixture into a fiber form, spraying the solution mixture into a powder form, or casting the solution mixture into an ingot form, and removing the solvent.
• the polymer solution mixture is sprayed to create a graphene- polymer composite coating or film, which is then pyrolyzed (carbonized or carbonized and graphitized).
• the consolidating step may include compacting the graphene-coated polymer particles in a porous green compact having macroscopic pores and then infiltrate or impregnate the pores with an additional carbon source material selected from a petroleum pitch, coal tar pitch, an aromatic organic material (e.g. naphthalene or other derivatives of a pitch), a monomer, an organic polymer, or a combination thereof.
• the organic polymer may contain a high carbon- yield polymer selected from phenolic resin, poly furfuryl alcohol, polyacrylonitrile, polyimide, polyamide, polyoxadiazole, polybenzoxazole, polybenzobisoxazole, polythiazole,
• polybenzothiazole polybenzobisthiazole, poly(p-phenylene vinylene), polybenzimidazole, polybenzobisimidazole, a copolymer thereof, a polymer blend thereof, or a combination thereof.
• these species become additional sources of carbon, if a higher amount of carbon in the hybrid foam is desired.
• the present invention also provides an integral 3D graphene-carbon hybrid foam composed of multiple pores and pore walls, wherein the pore walls contain single-layer or few- layer graphene sheets chemically bonded by a carbon material having a carbon material-to- graphene weight ratio from 1/200 to 1/2, wherein the few-layer graphene sheets have 2-10 layers of stacked graphene planes having an inter-plane spacing doo 2 from 0.3354 nm to 0.36 nm as measured by X-ray diffraction and the single-layer or few-layer graphene sheets contain a pristine graphene material having essentially zero % of non-carbon elements, or a non-pristine graphene material having 0.001% to 35% by weight (preferably 0.01% to 25%) of non-carbon elements wherein the non-pristine graphene is selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graph
• a plurality of single-layer or few layer graphene embracing the underlying polymer particles can overlap with one another to form a stack of graphene sheets.
• the stack can have a thickness greater than 5 nm and, in some cases, greater than 10 nm or even greater than 100 nm.
• the integral 3D graphene-carbon hybrid foam typically has a density from 0.001 to 1.7 g/cm 3 , and a specific surface area from 50 to 3,000 m 2 /g.
• the pore walls contain stacked graphene planes having an inter-planar spacing doo 2 from 0.3354 nm to 0.40 nm as measured by X-ray diffraction.
• the graphene-carbon preferably has an oxygen content from 1% to 25% by weight (more preferably 1-15% and most preferably 1-10%). This can be achieved if the starting material is oxidized graphite, or if the carbonization treatment is conducted in a lightly oxidizing environment at a temperature of 300- 1,500°C (preferably no greater than 1,000°C) and no subsequent graphitization is conducted.
• a highly porous graphene-carbon foam of this nature is capable of absorbing oil from an oil -water mixture up to 500% of its own weight.
• the graphene-carbon hybrid foam is preferably made by subjecting the carbon -bonded graphene sheets (after carbonization) to a graphitization treatment under a compressive stress. This facilitates orientation and re-organization (merging, growth, etc.) of graphene sheets or graphene domains.
• the graphene-carbon foam sheet or film exhibits a thermal conductivity of at least 200 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 2,000 S/cm per unit of specific gravity.
• the pore walls contain pristine graphene and the 3D solid graphene- carbon foam has a density from 0.001 to 1.7 g/cm 3 or an average pore size from 2 nm to 50 nm.
• the pore walls contain a non-pristine graphene material selected from the group consisting of graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, chemically functionalized graphene, and combinations thereof, and wherein the solid graphene foam contains a content of non-carbon elements in the range of 0.01% to 20% by weight.
• the non-carbon elements can include an element selected from oxygen, fluorine, chlorine, bromine, iodine, nitrogen, hydrogen, or boron.
• the pore walls contain graphene fluoride and the solid graphene foam contains a fluorine content from 0.01% to 20%) by weight.
• the pore walls contain graphene oxide and said solid graphene foam contains an oxygen content from 0.01%> to 20% by weight.
• the solid graphene-carbon hybrid foam has a specific surface area from 200 to 2,000 m 2 /g or a density from 0.01 to 1.5 g/cm 3 .
• the solid graphene-carbon hybrid foam is made into a continuous-length roll sheet form (a roll of a continuous foam sheet) having a thickness no less than 100 nm and no greater than 10 cm and a length of at least 1 meter long, preferably at least 2 meters, further preferably at least 10 meters, and most preferably at least 100 meters.
• This sheet roll is produced by a roll-to-roll process.
• the graphene- carbon foam preferably has an oxygen content or non-carbon content less than 1%> by weight, and the pore walls have stacked graphene planes having an inter-graphene spacing less than 0.35 nm, a thermal conductivity of at least 250 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 2,500 S/cm per unit of specific gravity.
• the graphene-carbon hybrid foam has an oxygen content or non-carbon content less than 0.01%> by weight and said pore walls contain stacked graphene planes having an inter-graphene spacing less than 0.34 nm, a thermal conductivity of at least 300 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 3,000 S/cm per unit of specific gravity.
• the graphene-carbon hybrid foam has an oxygen content or non-carbon content no greater than 0.01%> by weight and said pore walls contain stacked graphene planes having an inter-graphene spacing less than 0.336 nm, a mosaic spread value no greater than 0.7, a thermal conductivity of at least 350 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 3,500 S/cm per unit of specific gravity.
• the graphene foam has pore walls containing stacked graphene planes having an inter-graphene spacing less than 0.336 nm, a mosaic spread value no greater than 0.4, a thermal conductivity greater than 400 W/mK per unit of specific gravity, and/or an electrical conductivity greater than 4,000 S/cm per unit of specific gravity.
• the pore walls contain stacked graphene planes having an inter-graphene spacing less than 0.337 nm and a mosaic spread value less than 1.0.
• the graphene foam exhibits a degree of graphitization no less than 80% (preferably no less than 90%) and/or a mosaic spread value less than 0.4.
• the pore walls contain a 3D network of interconnected graphene planes.
• the solid graphene-carbon hybrid foam contains meso-scaled pores having a pore size from 2 nm to 50 nm.
• the solid graphene foam can also be made to contain micron-scaled pores (1-500 ⁇ ).
• the present invention also provides an oil-removing or oil-separating device, which contains the presently invented 3D graphene-carbon hybrid foam as an oil-absorbing element. Also provided is a solvent-removing or solvent-separating device containing the 3D graphene- carbon hybrid foam as a solvent-absorbing element.
• the invention also provides a method to separate oil from an oil-water mixture (e.g. oil- spilled water or waste water from oil sand).
• the method comprises the steps of (a) providing an oil-absorbing element comprising an integral graphene-carbon hybrid foam; (b) contacting an oil-water mixture with the element, which absorbs the oil from the mixture; and (c) retreating the element from the mixture and extracting the oil from the element.
• the method comprises a further step of (d) reusing the element.
• the invention provides a method to separate an organic solvent from a solvent-water mixture or from a multiple-solvent mixture.
• the method comprises the steps of (a) providing an organic solvent-absorbing element comprising an integral graphene-carbon hybrid foam; (b) bringing the element in contact with an organic solvent-water mixture or a multiple- solvent mixture containing a first solvent and at least a second solvent; (c) allowing this element to absorb the organic solvent from the mixture or absorb the first solvent from the at least second solvent; and (d) retreating the element from the mixture and extracting the organic solvent or first solvent from the element.
• the method contains an additional step (e) of reusing the element.
• FIG.1 A flow chart showing the most commonly used prior art process of producing highly oxidized NGPs that entails tedious chemical oxidation/intercalation, rinsing, and high- temperature exfoliation procedures.
• FIG.2(A) A flow chart showing the presently invented process for producing integral 3D
• FIG.2(B) Schematic of the heat-induced conversion of polymer into carbon, which bonds
• graphene sheets together to form a 3D graphene-carbon hybrid foam.
• the compacted structure of graphene-coated polymer particles is converted into a highly porous structure.
• FIG.3 (A) An SEM image of an internal structure of a 3D graphene-carbon hybrid foam.
• FIG.3(B) An SEM image of an internal structure of another 3D graphene-carbon hybrid foam
• FIG.4(A) Thermal conductivity values vs. specific gravity of a 3D integral graphene-carbon foam produced by the presently invented process, a meso-phase pitch-derived graphite foam, and a Ni foam-template assisted CVD graphene foam.
• FIG.4(B) Thermal conductivity values of 3D graphene-carbon foam and the hydrothermally reduced GO graphene foam.
• FIG.5 Thermal conductivity values of 3D graphene-carbon hybrid foam and pristine graphene foam (prepared by casting with a blowing agent and then heat treating) plotted as a function of the final (maximum) heat treatment temperature.
• FIG.6 Electrical conductivity values of 3D graphene-carbon foam and the hydrothermally
• FIG.7 The amount of oil absorbed per gram of integral 3D graphene-carbon hybrid foam, plotted as a function of the oxygen content in the foam having a porosity level of approximately
• FIG.8 The amount of oil absorbed per gram of integral 3D graphene-carbon hybrid foam, plotted as a function of the porosity level (given the same oxygen content).
• FIG.9 The amount of chloroform absorbed out of a chloroform-water mixture, plotted as a
• FIG.10 Schematic of heat sink structures (2 examples).
• the present invention provides a method of producing an integral 3D graphene-carbon hybrid foam directly from particles of a graphitic material and particles of a polymer.
• the method begins with mixing multiple particles of a graphitic material and multiple particles of a solid polymer carrier material to form a mixture, which is enclosed in an impacting chamber of an energy impacting apparatus (e.g. a vibratory ball mill, planetary ball mill, high energy mill, basket mill, agitator ball mill, cryo ball mill, micro ball mill, tumbler ball mill, continuous ball mill, stirred ball mill, pressurized ball mill, freezer mill, vibratory sieve, bead mill, nano bead mill, ultrasonic homogenizer mill, centrifugal planetary mixer, vacuum ball mill, or resonant acoustic mixer).
• an energy impacting apparatus e.g. a vibratory ball mill, planetary ball mill, high energy mill, basket mill, agitator ball mill, cryo ball mill, micro ball mill, tumbler ball mill, continuous ball mill, stirred ball mill, pressurized ball mill, freezer mill, vibratory sieve, bead mill, nano bead mill, ultrasonic homogenizer mill, centrifugal planetary
• such impacting events result in peeling off of graphene sheets from the graphitic material and transferring the graphene sheets to surfaces of the solid polymer carrier particles.
• These graphene sheets wrap around polymer particles to form graphene-coated or graphene-embedded polymer particles inside the impacting chamber. This is herein referred to as the "direct transfer" process, meaning that graphene sheets are directly transferred from graphite particles to surfaces of polymer particles without being mediated by any third-party entities.
• a plurality of impacting balls or media can be added to the impacting chamber of the energy impacting apparatus.
• step (c) includes operating a magnet to separate the impacting balls or media from the graphene-coated or graphene-embedded polymer particles.
• the method then includes recovering the graphene-coated or graphene-embedded polymer particles from the impacting chamber and consolidating the graphene-coated or graphene-embedded polymer particles into a desired shape of graphene-polymer composite structure.
• This consolidating step can be as simple as a compacting step that just mechanically packs graphene-coated or embedded particles into a desired shape. Alternatively, this
• Such a graphene-polymer structure can be in any practical shape or dimensions (fiber, rod, plate, cylinder, or any regular shape or odd shape).
• the graphene-polymer compact or composite structure is then pyrolyzed to thermally convert the polymer into carbon or graphite that bonds the graphene sheets to form the integral 3D graphene-carbon hybrid foam, as shown in FIG. 3(A) and FIG. 3(B).
• the high carbon-yield polymer may be selected from phenolic resin, poly furfuryl alcohol, polyacrylonitrile, polyimide, polyamide, polyoxadiazole, polybenzoxazole,
• polybenzobisoxazole polythiazole, polybenzothiazole, polybenzobisthiazole, poly(p-phenylene vinylene), polybenzimidazole, polybenzobisimidazole, a copolymer thereof, a polymer blend thereof, or a combination thereof.
• particles of these polymers become porous, as illustrated in the bottom portion of FIG. 2(B).
• the polymer can contain a low carbon-yield polymer selected from polyethylene, polypropylene, polybutylene, polyvinyl chloride, polycarbonate, acrylonitrile-butadiene (ABS), polyester, polyvinyl alcohol, poly vinylidiene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyphenylene oxide (PPO), poly methyl methacrylate (PMMA), a copolymer thereof, a polymer blend thereof, or a combination thereof.
• a low carbon-yield polymer selected from polyethylene, polypropylene, polybutylene, polyvinyl chloride, polycarbonate, acrylonitrile-butadiene (ABS), polyester, polyvinyl alcohol, poly vinylidiene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyphenylene oxide (PPO), poly methyl methacrylate (PMMA), a copolymer thereof, a polymer blend thereof, or a combination thereof
• an organic polymer typically contains a significant amount of non- carbon elements, which can be reduced or eliminated via heat treatments.
• pyrolyzation of a polymer causes the formation and evolution of volatile gas molecules, such as C0 2 and H 2 0, which lead to the formation of pores in the resulting polymeric carbon phase.
• volatile gas molecules such as C0 2 and H 2 0, which lead to the formation of pores in the resulting polymeric carbon phase.
• such pores also have a high tendency to get collapsed if the polymer is not constrained when being carbonized (the carbon structure can shrink while non-carbon elements are being released).
• the graphene sheets wrapped around a polymer particle are capable of constraining the carbon pore walls from being collapsed.
• some carbon species also permeate to the gaps between graphene sheets where these species bond the graphene sheets together.
• the pore sizes and pore volume (porosity level) of the resulting 3D integral graphene foam mainly depend upon the starting polymer size and the carbon yield of the polymer.
• the graphitic material as a source of graphene sheets, may be selected from natural graphite, synthetic graphite, highly oriented pyrolytic graphite, graphite fiber, graphitic nano- fiber, graphite fluoride, oxidized graphite, chemically modified graphite, exfoliated graphite, recompressed exfoliated graphite, expanded graphite, meso-carbon micro-bead, or a combination thereof.
• natural graphite synthetic graphite, highly oriented pyrolytic graphite, graphite fiber, graphitic nano- fiber, graphite fluoride, oxidized graphite, chemically modified graphite, exfoliated graphite, recompressed exfoliated graphite, expanded graphite, meso-carbon micro-bead, or a combination thereof.
• Graphene sheets can be peeled off from natural graphite by using polymer particles alone, without utilizing the heavier and harder impacting balls (such as zirconium dioxide or steel balls commonly used in a ball mill, for instance).
• the peeled-off graphene sheets are directly transferred to polymer particle surfaces and are firmly wrapped around the polymer particles.
• impacting polymer particles are capable of peeling off graphene sheets from artificial graphite, such as meso-carbon micro-beads (MCMBs), which are known to have a skin layer of amorphous carbon.
• MCMBs meso-carbon micro-beads
• the present invention provides a strikingly simple, fast, scalable, environmentally
• a certain desired degree of hydrophilicity can be imparted to the pore walls of the graphene-carbon hybrid foam if the starting graphite is intentionally oxidized to some degree (e.g. to contain 2-15% by weight of oxygen).
• oxygen- containing functional groups can be attached to the carbon phase if the carbonization treatment is allowed to occur in a slightly oxidizing environment.
• the graphitic material may be selected from a non-intercalated and non-oxidized graphitic material that has never been previously exposed to a chemical or oxidation treatment prior to being placed into the impacting chamber.
• the graphene-carbon foam can be subjected to graphitization treatment at a temperature higher than 2,500°C. The resulting material is particularly useful for thermal management applications (e.g. for use to make a finned heat sink, a heat exchanger, or a heat spreader.
• the graphene-carbon foam may be subjected to compression during and/or after the graphitization treatment. This operation enables us to adjust the graphene sheet orientation and the degree of porosity.
• the graphene foam walls having a d 0 0 2 higher than 0.3440 nm reflects the presence of oxygen- or fluorine-containing functional groups (such as -F, -OH, >0, and - COOH on graphene molecular plane surfaces or edges) that act as a spacer to increase the inter- graphene spacing.
• oxygen- or fluorine-containing functional groups such as -F, -OH, >0, and - COOH on graphene molecular plane surfaces or edges
• Another structural index that can be used to characterize the degree of ordering of the stacked and bonded graphene planes in the foam walls of graphene and conventional graphite crystals is the "mosaic spread," which is expressed by the full width at half maximum of a rocking curve (X-ray diffraction intensity) of the (002) or (004) reflection.
• This degree of ordering characterizes the graphite or graphene crystal size (or grain size), amounts of grain boundaries and other defects, and the degree of preferred grain orientation.
• a nearly perfect single crystal of graphite is characterized by having a mosaic spread value of 0.2-0.4. Most of our graphene walls have a mosaic spread value in this range of 0.2-0.4 (if produced with a heat treatment temperature (HTT) no less than 2,500°C). However, some values are in the range of 0.4-0.7 if the HTT is between 1,500 and 2,500°C, and in the range of 0.7-1.0 if the HTT is between 300 and 1,500°C.
• HTT heat treatment temperature
• the integral 3D graphene-carbon hybrid foam is composed of multiple pores and pore walls, wherein the pore walls contain single-layer or few-layer graphene sheets chemically bonded by a carbon material having a carbon material-to-graphene weight ratio from 1/100 to 1/2, wherein the few-layer graphene sheets have 2-10 layers of stacked graphene planes having an inter-plane spacing d 0 02 from 0.3354 nm to 0.36 nm as measured by X-ray diffraction and the single-layer or few-layer graphene sheets contain a pristine graphene material having essentially zero % of non-carbon elements, or a non-pristine graphene material having 0.01% to 25% by weight of non-carbon elements (more typically ⁇ 15%) wherein the non-pristine graphene is selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene,
• a plurality of single-layer or few layer graphene embracing the underlying polymer particles can overlap with one another to form a stack of graphene sheets.
• the stack can have a thickness greater than 5 nm and, in some cases, greater than 10 nm or even greater than 100 nm.
• the integral 3D graphene-carbon hybrid foam typically has a density from 0.001 to 1.7 g/cm 3 , a specific surface area from 50 to 3,000 m 2 /g, a thermal conductivity of at least 200 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 2,000 S/cm per unit of specific gravity.
• the pore walls contain stacked graphene planes having an inter-planar spacing d 0 02 from 0.3354 nm to 0.40 nm as measured by X-ray diffraction.
• the graphene sheets can be merged edge to edge through covalent bonds with one another, into an integrated graphene entity.
• the gaps between the free ends of those unmerged sheets or shorter merged sheets are bonded by the carbon phase converted from a polymer. Due to these unique chemical composition (including oxygen or fluorine content, etc.), morphology, crystal structure (including inter-graphene spacing), and structural features (e.g. degree of orientations, few defects, chemical bonding and no gap between graphene sheets, and substantially no interruptions along graphene plane directions), the graphene-carbon hybrid foam has a unique combination of outstanding thermal conductivity, electrical conductivity, mechanical strength, and stiffness (elastic modulus).
• the integral 3D graphene-carbon hybrid foam an ideal element for a broad array of engineering and biomedical applications.
• the graphene-carbon foam can be used in the following applications:
• the graphene-carbon hybrid foam being compressible and of high thermal conductivity, is ideally suited for use as a thermal interface material (TEVI) that can be implemented between a heat source and a heat spreader or between a heat source and a heat sink.
• TEVI thermal interface material
• the hybrid foam can be used as a heat spreader per se due to its high thermal
• the hybrid foam can be used as a heat sink or heat dissipating material due to his high heat-spreading capability (high thermal conductivity) and high heat-dissipating capability (large number of surface pores inducing massive air-convection micro or nano channels).
• the light weight low density adjustable between 0.001 and 1.8 g/cm 3 ), high thermal conductivity per unit specific gravity or per unit of physical density, and high structural integrity (graphene sheets being bonded by carbon) make this hybrid foam an ideal material for a durable heat exchanger.
• the graphene-carbon hybrid foam-based thermal management or heat dissipating devices include a heat exchanger, a heat sink (e.g. finned heat sink), a heat pipe, high-conductivity insert, thin or thick conductive plate (between a heat sink and a heat source), thermal interface medium (or thermal interface material, TIM), thermoelectric or Peltier cooling plate, etc.
• a heat exchanger e.g. finned heat sink
• a heat pipe e.g. finned heat sink
• high-conductivity insert e.g. finned heat sink
• thin or thick conductive plate between a heat sink and a heat source
• thermal interface medium or thermal interface material, TIM
• thermoelectric or Peltier cooling plate e.g., thermoelectric or Peltier cooling plate, etc.
• a heat exchanger is a device used to transfer heat between one or more fluids; e.g. a gas and a liquid separately flowing in different channels.
• the fluids are typically separated by a solid wall to prevent mixing.
• the presently invented graphene-carbon hybrid foam material is an ideal material for such a wall provided the foam is not a totally open-cell foam that allows for mixing of fluids.
• the presently invented method enables production of both open-cell and closed-cell foam structures. The high surface pore areas enable dramatically faster exchange of heats between the two or multiple fluids.
• Heat exchangers are widely used in refrigeration systems, air conditioning units, heaters, power stations, chemical plants, petrochemical plants, petroleum refineries, natural-gas processing, and sewage treatment.
• a well-known example of a heat exchanger is found in an internal combustion engine in which a circulating engine coolant flows through radiator coils while air flows past the coils, which cools the coolant and heats the incoming air.
• the solid walls e.g. that constitute the radiator coils
• the presently invented graphene foam having either a higher thermal conductivity or higher specific surface area is a superior alternative to Cu and Al, for instance.
• heat exchangers There are many types of heat exchangers that are commercially available: shell and tube heat exchanger, plate heat exchangers, plate and shell heat exchanger, adiabatic wheel heat exchanger, plate fin heat exchanger, pillow plate heat exchanger, fluid heat exchangers, waste heat recovery units, dynamic scraped surface heat exchanger, phase-change heat exchangers, direct contact heat exchangers, and microchannel heat exchangers. Every one of these types of heat exchangers can take advantage of the exceptional high thermal conductivity and specific surface area of the presently invented foam material.
• the presently invented solid graphene foam can also be used in a heat sink.
• Heat sinks are widely used in electronic devices for heat dissipation purposes.
• the central processing unit (CPU) and battery in a portable microelectronic device such as a notebook computer, tablet, and smart phone
• CPU central processing unit
• a portable microelectronic device such as a notebook computer, tablet, and smart phone
• a metal or graphite object e.g. Cu foil or graphite foil
• TIM thin thermal interface material mediates between the hot surface of the heat source and a heat spreader or a heat-spreading surface of a heat sink.
• a heat sink usually consists of a high-conductivity material structure with one or more flat surfaces to ensure good thermal contact with the components to be cooled, and an array of comb or fin like protrusions to increase the surface contact with the air, and thus the rate of heat dissipation.
• a heat sink may be used in conjunction with a fan to increase the rate of airflow over the heat sink.
• a heat sink can have multiple fins (extended or protruded surfaces) to improve heat transfer. In electronic devices with limited amount of space, the shape/arrangement of fins must be optimized such that the heat transfer density is maximized.
• cavities inverted fins may be embedded in the regions formed between adjacent fins. These cavities are effective in extracting heat from a variety of heat generating bodies to a heat sink.
• an integrated heat sink comprises a heat collection member (core or base) and at least one heat dissipation member (e.g. a fin or multiple fins) integral to the heat collection member (base) to form a finned heat sink.
• the fins and the core are naturally connected or integrated together into a unified body without using an externally applied adhesive or mechanical fastening means to connect the fins to the core.
• the heat collection base has a surface in thermal contact with a heat source (e.g. a LED), collects heat from this heat source, and dissipates heat through the fins into the air.
• a heat source e.g. a LED
• the first one contains a heat collection member (or base member) 304 and multiple fins or heat dissipation members (e.g. fin 306) connected to the base member 304.
• the base member 304 is shown to have a heat collection surface 314 intended to be in thermal contact with a heat source.
• the heat dissipation member or fin 306 is shown to have at least a heat dissipation surface 320.
• a particularly useful embodiment is an integrated radial heat sink 302 comprising a radial finned heat sink assembly that comprises: (a) a base 308 comprising a heat collection surface 318; and (b) a plurality of spaced parallel planar fin members (e.g. 310, 312 as two examples) supported by or integral with the base 308, wherein the planar fin members (e.g. 310) comprise the at least one heat dissipation surface 322. Multiple parallel planar fin members are preferably equally spaced.
• the presently invented graphene-carbon hybrid foam being highly elastic and resilient, is itself a good thermal interface material and a highly effective heat spreading element as well.
• this high-conductivity foam can also be used as an inserts for electronic cooling and for enhancing the heat removal from small chips to a heat sink. Because the space occupied by high conductivity materials is a major concern, it is a more efficient design to make use of high conductivity pathways that can be embedded into a heat generating body.
• the elastic and highly conducting solid graphene foam herein disclosed meets these requirements perfectly.
• the high elasticity and high thermal conductivity make the presently invented solid graphene-carbon hybrid foam a good conductive thick plate to be placed as a heat transfer interface between a heat source and a cold flowing fluid (or any other heat sink) to improve the cooling performance.
• the heat source is cooled under the thick graphene foam plate instead of being cooled in direct contact with the cooling fluid.
• the thick plate of graphene foam can significantly improve the heat transfer between the heat source and the cooling fluid by way of conducting the heat current in an optimal manner. No additional pumping power and no extra heat transfer surface area are required.
• a heat pipe is a heat transfer device that uses evaporation and condensation of a two-phase working fluid or coolant to transport large quantities of heat with a very small difference in temperature between the hot and cold interfaces.
• a conventional heat pipe consists of sealed hollow tube made of a thermally conductive metal such as Cu or Al, and a wick to return the working fluid from the evaporator to the condenser.
• the pipe contains both saturated liquid and vapor of a working fluid (such as water, methanol or ammonia), all other gases being excluded.
• a working fluid such as water, methanol or ammonia
• the heat pipe for electronics thermal management can have a solid graphene foam envelope and wick, with water as the working fluid.
• Graphene/ methanol may be used if the heat pipe needs to operate below the freezing point of water, and graphene/ammonia heat pipes may be used for electronics cooling in space.
• Peltier cooling plates operate on the Peltier effect to create a heat flux between the junction of two different conductors of electricity by applying an electric current. This effect is commonly used for cooling electronic components and small instruments. In practice, many such junctions may be arranged in series to increase the effect to the amount of heating or cooling required.
• the solid graphene foam may be used to improve the heat transfer efficiency.
• the solid graphene foam can be made to contain microscopic pores ( ⁇ 2 nm) or meso- scaled pores having a pore size from 2 nm to 50 nm.
• the solid graphene-carbon hybrid foam can also be made to contain micron-scaled pores (1-500 ⁇ ). Based on well-controlled pore size alone, the instant graphene-carbon foam can be an exceptional filter material for air or water filtration.
• graphene pore wall chemistry and carbon phase chemistry can be
• the concurrent or independent control of both pore sizes and chemical functional groups at different sites of the internal structure provide unprecedented flexibility or highest degree of freedom in designing and making graphene-carbon hybrid foams that exhibit many unexpected properties, synergistic effects, and some unique combination of properties that are normally considered mutually exclusive (e.g. some part of the structure is hydrophobic and other part hydrophilic; or the foam structure is both hydrophobic and oleophilic).
• a surface or a material is said to be hydrophobic if water is repelled from this material or surface and that a droplet of water placed on a hydrophobic surface or material will form a large contact angle.
• a surface or a material is said to be oleophilic if it has a strong affinity for oils and not for water. The present method allows for precise control over hydrophobicity, hydrophilicity, and oleophilicity.
• the present invention also provides an oil-removing, oil-separating, or oil-recovering device, which contains the presently invented 3D graphene-carbon hybrid foam as an oil- absorbing or oil-separating element. Also provided is a solvent-removing or solvent-separating device containing the 3D graphene-carbon hybrid foam as a solvent-absorbing element.
• a major advantage of using the instant graphene-carbon hybrid foam as an oil-absorbing element is its structural integrity. Due to the notion that graphene sheets are chemically bonded by the carbon material, the resulting foam would not get disintegrated upon repeated oil absorption operations. In contrast, we have discovered that graphene-based oil-absorbing elements prepared by hydrothermal reduction, vacuum-assisted filtration, or freeze-drying get disintegrated after absorbing oil for 2 or 3 times. There is just nothing (other than weak van der Waals forces existing prior to first contact with oil) to hold these otherwise separated graphene sheets together. Once these graphene sheets are wetted by oil, they no longer are able to return to the original shape of the oil-absorbing element.
• Another major advantage of the instant technology is the flexibility in designing and making oil-absorbing elements that are capable of absorbing oil up to an amount as high as 400 times of its own weight yet still maintaining its structural shape (without significant expansion). This amount depends upon the specific pore volume of the foam, which can be controlled mainly by the ratio between the amount of original carrier polymer particles and the amount of graphene sheets prior to the heat treatment.
• the invention also provides a method to separate/recover oil from an oil-water mixture (e.g. oil-spilled water or waste water from oil sand).
• the method comprises the steps of (a) providing an oil-absorbing element comprising an integral graphene-carbon hybrid foam; (b) contacting an oil-water mixture with the element, which absorbs the oil from the mixture; and (c) retreating the oil-absorbing element from the mixture and extracting the oil from the element.
• the method comprises a further step of (d) reusing the element.
• the invention provides a method to separate an organic solvent from a solvent-water mixture or from a multiple-solvent mixture.
• the method comprises the steps of (a) providing an organic solvent-absorbing element comprising an integral graphene-carbon hybrid foam; (b) bringing the element in contact with an organic solvent-water mixture or a multiple- solvent mixture containing a first solvent and at least a second solvent; (c) allowing this element to absorb the organic solvent from the mixture or absorb the first solvent from the at least second solvent; and (d) retreating the element from the mixture and extracting the organic solvent or first solvent from the element.
• the method contains an additional step (e) of reusing the solvent-absorbing element.
• a sample of the coated carrier material was then immersed in tetrachloroethylene at 80°C for 24 hours to dissolve PP and allow graphene sheets to disperse in the organic solvent. After solvent removal, isolated graphene sheet powder was recovered (mostly few-layer graphene). The remaining coated carrier material was then compacted in a mold cavity to form a green compact, which was then heat-treated in a sealed crucible at 350°C and then at 600°C for 2 hours to produce a graphene-carbon foam.
• polypropylene PP
• the carrier material for graphene-carbon hybrid foam production is not limited to PP. It could be any polymer
• thermoplastic thermoset, rubber, wax, mastic, gum, organic resin, etc.
• thermosetting resins such as epoxide and imide-based oligomers or rubber
• room temperature or lower e.g. cryogenic temperature
• even partially cured thermosetting resin particles can be used as a polymer carrier.
• EXAMPLE 2 Graphene-carbon hybrid foam using expanded graphite (> 100 nm in thickness) as the graphene source and ABS as the polymer solid carrier particles
• EXAMPLE 3 Production of graphene-carbon hybrid foam from meso-carbon micro beads (MCMBs as the graphene source material)) and polyacrylonitrile (PAN) fibers (as solid carrier particles)
• MCMBs meso-carbon micro beads
• PAN polyacrylonitrile
• the films were subjected to a heat treatment at 250°C for 1 hour (in room air), 350°C for 2 hours, and 1,000°C for 2 hours (under an argon gas atmosphere) to obtain graphene-carbon foam layers.
• Half of the carbonized foam layers were then heated to 2,850°C and maintained at this temperature for 0.5 hours.
• EXAMPLE 4 Particles of cured phenolic resin as the polymer carrier in a freezer mill
• a mass of graphene-coated resin particles was compressed to form a green compact, which was then infiltrated with a small amount of petroleum pitch. Separately, another green compact of graphene-coated resin particles was prepared under comparable conditions, but no pitch infiltration was attempted. The two compacts were then subjected to identical pyrolysis treatments.
• EXAMPLE 5 Natural graphite particles as the graphene source, polyethylene (PE) or nylon 6/6 beads as the solid carrier particles, and ceramic or glass beads as added impacting balls
• a mass of graphene-coated PE pellets and a mass of graphene-coated nylon beads were separately compacted in a mold cavity and briefly heated above the melting point of PE or nylon and then rapidly cooled to form two green compacts. For comparison purposes, two
• the experiment began with preparation of micron-sized rubber particles.
• a mixture of methylhydro dimetbyl-siloxane polymer (20 g) and polydimethylsiloxane, vinyldimethy3 terminated polymer (30 g) was obtained by using a homogenizer under ambient conditions for 1 minute. Tween 80 (4.6 g) was added and the mixture was homogenized for 20 seconds.
• Piatinum-divinyitetramethyldisiJoxane complex (0.5 g in 15 g methanol) was added and mixed for 10 seconds. This mixture was added to 350 g of distilled water and a stable latex was obtained by homogenization for 15 minutes. The latex was heated to 60°C for 15 hours. The latex was then de-emulsified with anhydrous sodium sulfate (20 g) and the silicone rubber particles were obtained by filtration under a vacuum, washing with distilled water, and drying under vacuum at 25°C. The particle size distribution of the resulting rubber particles was 3-11 ⁇ .
• Some GO foam samples were mixed with different proportions of urea and the mixtures were heated in a microwave reactor (900 W) for 0.5 to 5 minutes. The products were washed several times with deionized water and vacuum dried. The products obtained were nitrogenated graphene foam. The nitrogen contents were from 3% to 17.5 wt. %, as measured by elemental analysis.
• oxidized graphene-carbon hybrid foam structures are particularly effective as an absorber of oil from an oil-water mixture (i.e. oil spilled on water and then mixed together).
• the integral 3D graphene (0-15% by wt. oxygen)-carbon foam structures are both hydrophobic and oleophilic (FIG. 7 and FIG. 8).
• a surface or a material is said to be hydrophobic if water is repelled from this material or surface and that a droplet of water placed on a hydrophobic surface or material will form a large contact angle.
• a surface or a material is said to be oleophilic if it has a strong affinity for oils and not for water.
• COMPARATIVE EXAMPLE 1 Graphene via Hummer's Process and carbonization of graphene-polymer composite
• Graphite oxide as prepared by oxidation of graphite flakes with sulfuric acid, nitrate, and permanganate according to the method of Hummers [US Pat. No. 2,798,878, Jul. 9, 1957]. Upon completion of the reaction, the mixture was poured into deionized water and filtered. The graphite oxide was repeatedly washed in a 5% solution of HC1 to remove most of the sulphate ions. The sample was then washed repeatedly with deionized water until the pH of the filtrate was neutral. The slurry was spray-dried and stored in a vacuum oven at 60° C. for 24 hours.
• the interlayer spacing of the resulting laminar graphite oxide was determined by the Debey-Scherrer X-ray technique to be approximately 0.73nm (7.3 A).
• a sample of this material was subsequently transferred to a furnace pre-set at 650°C for 4 minutes for exfoliation and heated in an inert atmosphere furnace at 1200° C for 4 hours to create a low density powder comprised of few-layer reduced graphene oxide (RGO). Surface area was measured via nitrogen adsorption BET.
• This powder was subsequently dry mixed at a l%-25% loading level with ABS, PE, PP, and nylon pellets, respectively, and compounded using a 25mm twin screw extruder to form composite sheets. These composite sheets were then pyrolyzed.
• COMPARATIVE EXAMPLE 2 Preparation of single-layer graphene oxide (GO) sheets from meso-carbon micro-beads (MCMBs) and then production of graphene foam layers from GO sheets
• MCMBs Meso-carbon microbeads
• This material has a density of about 2.24 g/cm 3 with a median particle size of about 16 ⁇ .
• MCMB (10 grams) were intercalated with an acid solution (sulfuric acid, nitric acid, and potassium permanganate at a ratio of 4: 1 :0.05) for 48-96 hours. Upon completion of the reaction, the mixture was poured into deionized water and filtered. The intercalated MCMBs were repeatedly washed in a 5% solution of HC1 to remove most of the sulphate ions.
• the sample was then washed repeatedly with deionized water until the pH of the filtrate was no less than 4.5.
• the slurry was then subjected ultrasoni cation for 10-100 minutes to produce GO suspensions.
• TEM and atomic force microscopic studies indicate that most of the GO sheets were single-layer graphene when the oxidation treatment exceeded 72 hours, and 2- or 3-layer graphene when the oxidation time was from 48 to 72 hours.
• the GO sheets contain oxygen proportion of approximately 35%-47% by weight for oxidation treatment times of 48-96 hours.
• GO sheets were suspended in water. Baking soda (5- 20% by weight), as a chemical blowing agent, was added to the suspension just prior to casting. The suspension was then cast onto a glass surface. Several samples were cast, some containing a blowing agent and some not. The resulting GO films, after removal of liquid, have a thickness that can be varied from approximately 10 to 500 ⁇ .
• Several sheets of the GO film, with or without a blowing agent were then subjected to heat treatments that involve a heat temperature of 80-500°C for 1-5 hours, which generated a graphene foam structure.
• COMPARATIVE EXAMPLE 3 Preparation of pristine graphene foam (0% oxygen)
• interconnected 3D scaffold of nickel was chosen as a template for the growth of graphene foam. Briefly, carbon was introduced into a nickel foam by decomposing CH 4 at 1,000°C under ambient pressure, and graphene films were then deposited on the surface of the nickel foam. Due to the difference in the thermal expansion coefficients between nickel and graphene, ripples and wrinkles were formed on the graphene films. In order to recover (separate) graphene foam, Ni frame must be etched away.
• PMMA poly(methyl methacrylate)
• COMPARATIVE EXAMPLE 5 Conventional graphitic foam from pitch-based carbon foams Pitch powder, granules, or pellets are placed in a aluminum mold with the desired final shape of the foam. Mitsubishi ARA-24 meso-phase pitch was utilized. The sample is evacuated to less than 1 torr and then heated to a temperature approximately 300°C. At this point, the vacuum was released to a nitrogen blanket and then a pressure of up to 1,000 psi was applied. The temperature of the system was then raised to 800°C. This was performed at a rate of 2 degree C/min.
• the temperature was held for at least 15 minutes to achieve a soak and then the furnace power was turned off and cooled to room temperature at a rate of approximately 1.5 degree C/min with release of pressure at a rate of approximately 2 psi/min.
• Final foam temperatures were 630°C and 800°C. During the cooling cycle, pressure is released gradually to atmospheric conditions.
• the foam was then heat treated to 1050°C (carbonized) under a nitrogen blanket and then heat treated in separate runs in a graphite crucible to 2500°C and 2800°C (graphitized) in Argon.
• a self-assembled graphene hydrogel (SGH) sample was prepared by a one-step hydrothermal method.
• the SGH can be easily prepared by heating 2 mg/mL of homogeneous graphene oxide (GO) aqueous dispersion sealed in a Teflon- lined autoclave at 180°C for 12 h.
• the SGH containing about 2.6% (by weight) graphene sheets and 97.4% water has an electrical conductivity of approximately 5 x 10 "3 S/cm.
• the resulting graphene foam Upon drying and heat treating at 1,500°C, the resulting graphene foam exhibits an electrical conductivity of approximately 1.5 x 10 "1 S/cm, which is 2 times lower than those of the presently invented graphene foams produced by heat treating at the same temperature.
• the compression strength of the samples having an average density of 0.51 g/cm 3 was measured to be 3.6 MPa and the compression modulus was measured to be 74 MPa.
• the compression strength and compressive modulus of the presently invented graphene-carbon foam samples having a comparable physical density are 6.2 MPa and 113 MPa, respectively.
• FIG.4(A) Shown in FIG.4(A) are the thermal conductivity values vs. specific gravity of the 3D graphene-carbon foam, meso-phase pitch-derived graphite foam, and Ni foam template-assisted CVD graphene foam.
• the 3D integral graphene-carbon foams produced by the presently invented process exhibit significantly higher thermal conductivity as compared to both meso-phase pitch- derived graphite foam and Ni foam template-assisted CVD graphene, given the same physical density.
• CVD graphene is essentially pristine graphene that has never been exposed to oxidation and should have exhibited a high thermal conductivity compared to our graphene-carbon hybrid foam.
• the carbon phase of the hybrid foam is in general of low degree of crystallinity (some being amorphous carbon) and, thus, has much lower thermal or electrical conductivity as compared with graphene alone.
• the carbon phase is coupled with graphene sheets to form an integral structure produced by the presently invented method, the resulting hybrid form exhibits a thermal conductivity as compared to an all-pristine graphene foam.
• the specific conductivity values of the presently invented hybrid foam materials exhibit values from 250 to 500 W/mK per unit of specific gravity; but those of other types of foam materials are typically lower than 250 W/mK per unit of specific gravity.
• FIG.4(B) shows the thermal conductivity values of the presently invented hybrid foam and hydrothermally reduced GO graphene foam. Electrical conductivity values of 3D graphene-carbon foam and the hydrothermally reduced GO graphene foam are shown in FIG.6. These data further support the notion that, given the same amount of solid material, the presently invented graphene-carbon foam is intrinsically most conducting, reflecting the significance of continuity in electron and phonon transport paths. The carbon phase bridges the gaps or interruptions between graphene sheets.
• EXAMPLE 10 Characterization of various graphene foams and conventional graphite foam The internal structures (crystal structure and orientation) of several series of graphene- carbon foam materials were investigated using X-ray diffraction.
• the graphene walls of the hybrid foam materials exhibit a d 0 o 2 spacing typically from 0.3345 nm to 0.40 nm, but more typically up to 0.34 nm.
• the doo 2 spacing is decreased to approximately to 0.3354 nm, identical to that of a graphite single crystal.
• the (004) peak intensity relative to the (002) intensity on the same diffraction curve, or the 7(004)//(002) ratio, is a good indication of the degree of crystal perfection and preferred orientation of graphene planes.
• the (004) peak is either non-existing or relatively weak, with the 7(004)//(002) ratio ⁇ 0.1, for all graphitic materials heat treated at a temperature lower than 2,800°C.
• the 7(004)//(002) ratio for the graphitic materials heat treated at 3,000-3,250°C is in the range of 0.2-0.5.
• a graphene foam prepared with a final HTT of 2,750°C for one hour exhibits a 7(004)//(002) ratio of 0.78 and a Mosaic spread value of 0.21, indicating the pore walls being a practically perfect graphene single crystal with a good degree of preferred orientation (if prepared under a compression force).
• the "mosaic spread” value is obtained from the full width at half maximum of the (002) reflection in an X-ray diffraction intensity curve.
• This index for the degree of ordering characterizes the graphite or graphene crystal size (or grain size), amounts of grain boundaries and other defects, and the degree of preferred grain orientation.
• a nearly perfect single crystal of graphite is characterized by having a mosaic spread value of 0.2-0.4.
• Some of our graphene foams have a mosaic spread value in this range of 0.3-0.6 when produced using a final heat treatment temperature no less than 2,500°C.
• harder polymer particles e.g. PE, PP, nylon, ABS, polystyrene, high impact polystyrene, etc. and their filler-reinforced versions
• softer polymer particles e.g. rubber, PVC, polyvinyl alcohol, latex particles
• all polymer balls are capable of supporting from 0.001%) to approximately 80%> by weight of graphene sheets (mostly few-layer graphene, ⁇ 10 layers, if over 30%> by weight of graphene sheets).
• the presently invented method also allows for convenient and flexible control over the chemical composition (e.g. F, O, and N contents, etc.), responsive to various application needs (e.g. oil recovery from oil-contaminated water, separation of an organic solvent from water or other solvents, heat dissipation, etc.).
• chemical composition e.g. F, O, and N contents, etc.
• application needs e.g. oil recovery from oil-contaminated water, separation of an organic solvent from water or other solvents, heat dissipation, etc.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Ceramic Engineering (AREA)
• Analytical Chemistry (AREA)
• Materials Engineering (AREA)
• Inorganic Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Structural Engineering (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Dispersion Chemistry (AREA)
• Carbon And Carbon Compounds (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Cell Electrode Carriers And Collectors (AREA)
• Treatment Of Liquids With Adsorbents In General (AREA)
• Removal Of Floating Material (AREA)
• Water Treatment By Sorption (AREA)

Priority Applications (3)

Applications Claiming Priority (4)

Publications (1)

Family

ID=59225530

Family Applications (1)

Country Status (4)

Cited By (18)

Families Citing this family (11)

Citations (4)

Family Cites Families (22)

• 2016
  • 2016-12-09 CN CN201680072981.8A patent/CN108602046B/zh active Active
  • 2016-12-09 WO PCT/US2016/065929 patent/WO2017116657A1/en active Application Filing
  • 2016-12-09 KR KR1020187018783A patent/KR102584293B1/ko active IP Right Grant
  • 2016-12-09 JP JP2018533602A patent/JP7038659B2/ja active Active

Patent Citations (4)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events