WO2012044382A1

WO2012044382A1 - Process of forming nano-composites and nano-porous non-wovens

Info

Publication number: WO2012044382A1
Application number: PCT/US2011/041432
Authority: WO
Inventors: Hao Zhou; Walter A. Scrivens
Original assignee: Milliken & Company
Priority date: 2010-09-29
Filing date: 2011-06-22
Publication date: 2012-04-05

Abstract

A process for forming a nano-composite including mixing a first and second thermoplastic polymer in a molten state forming a molten polymer blend. The second polymer is soluble in a first solvent and the first polymer is insoluble in the first solvent. The first polymer forms discontinuous regions in the second polymer. Next, the polymer blend is subjected to extensional flow, shear stress, and heat forming nanofibers where less than about 30% by volume of the nanofibers are bonded to other nanofibers. Next the polymer blend with nanofibers is cooled and the first intermediate is formed into a pre-consolidation formation. The pre-consolidation formation is then consolidated causing nanofiber movement, randomization, and at least 70% by volume of the nanofibers to fuse to other nanofibers. According to one aspect, the second intermediate is then subjected to the first solvent to the dissolving away at least a portion of the second polymer.

Description

PROCESS OF FORMING NANO-COMPOSITES AND NANO-POROUS NON-

WOVENS

TECHNICAL FIELD

[0001 ] The present application is directed to processes for forming nano- composites and nano-porous non-wovens.

BACKGROUND

[0002] Nanofibers have a high surface area to volume ratio which alters the mechanical, thermal, and catalytic properties of materials. Adding nanofibers to composites may either expand or add novel performance attributes such as a reduction in weight, an increase in breathability, an increase in moisture wicking, an increase in absorbency, an increase in reaction rate, etc. The market applications for nanofibers are rapidly growing and promise to be diverse.

Applications include filtration, barrier fabrics, insulation, absorbable pads and wipes, personal care, biomedical and pharmaceutical applications, whiteners (such as Ti0₂ substitution) or enhanced web opacity, nucleators, reinforcing agents, acoustic substrates, apparel, energy storage, etc. Due to their limited mechanical properties that preclude the use of conventional web handing, loosely interlaced nanofibers are often applied to a supporting substrate such as a non-woven or fabric material. The bonding of the nanofiber cross over points may be able to increase the mechanical strength of the non-wovens which potentially help with their mechanical handling and offer superior physical performance.

[0003] Both particles (especially nano-particles) and nanofibers have been in the interest of various industries due to the high surface area to volume ratio offered by these materials. By incorporating nano-particles (or other sized particles) in a nano-composite, one can add additional functionalities that can be useful in many applications such as catalysis, microelectronic, medicine, antimicrobial, sensing, magnetics, electrochemistry, and optics. By designing the appropriate particle size to fiber size, interesting flow or filtration properties can also achieved.

BRIEF SUMMARY

[0004] The present disclosure provides a process for forming a nano- composite article including mixing a first thermoplastic polymer and a second thermoplastic polymer in a molten state forming a polymer blend. The second polymer is soluble in a first solvent and the first polymer is insoluble in the first solvent. The first polymer forms discontinuous regions in the second polymer. Next, the polymer blend is subjected to extensional flow, shear stress, and heat such that the first polymer forms nanofibers having an aspect ratio of at least 5:1 and wherein less than about 30% by volume of the nanofibers are bonded to other nanofibers. The nanofibers are generally aligned along an axis.

[0005] Next the polymer blend with nanofibers is cooled to a temperature below the softening temperature of the first polymer to preserve the nanofiber shape forming a first intermediate. Then the first intermediate is formed into a pre-consolidation formation.

[0006] The pre-consolidation formation is then consolidated at a consolidation temperature that is above the T_g of both the first polymer and second polymer causing nanofiber movement, randomization, and at least 70% by volume of the nanofibers to fuse to other nanofibers. According to one aspect, the second intermediate is then subjected to the first solvent to the dissolving away at least a portion of the second polymer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 illustrates a cross-section of one embodiment of a nano- porous non-woven. [0008] Figure 2 illustrates a cross-section of one embodiment of a nano- composite.

[0009] Figure 3 illustrates a process flow diagram for forming a nano- composite.

[0010] Figure 4 illustrates a cross-section of the blend of the first polymer and the second polymer after mixing.

[001 1 ] Figure 5 illustrates a cross-section of one embodiment of a nano- porous non-woven containing core/shell nanofibers.

[0012] Figure 6 illustrates a cross-section of a nano-porous non-woven with a third component.

[0013] Figure 7 illustrates a cross-section of a nano-composite with a third component.

[0014] Figure 8 illustrates the gradient within the nanofibers and the bonding between the nanofibers.

[0015] Figure 9 illustrates a cross-section of one embodiment of the nano- porous non-woven containing nano-particles.

[0016] Figure 10 illustrates a cross-section of one embodiment of the nano-composite containing nano-particles.

[0017] Figure 1 1 illustrates one embodiment of a nano-porous non-woven containing a textile layer.

[0018] Figure 12 illustrates an enlargement of one embodiment of the nano-porous non-woven containing a textile layer.

[0019] Figure 13 illustrates one embodiment of the nano-porous non- woven containing a textile layer.

[0020] Figure 14 illustrates one embodiment of the nano-composite containing a textile layer.

[0021 ] Figure 15 illustrates a cross-section of one embodiment of the nano-composite having one support layer. [0022] Figure 16 illustrates a cross-section of one embodiment of the nano-porous non-woven having one support layer.

[0023] Figure 17 illustrates a cross-section of one embodiment of the nano-porous non-woven.

[0024] Figure 18 illustrates a cross-section of one embodiment of the nano-composite having two support layers.

[0025] Figure 19 illustrates a cross-section of one embodiment of the nano-porous non-woven having two support layers.

[0026] Figure 20 illustrates a cross-section of one embodiment of the nano-porous non-woven.

[0027] Figure 21 illustrates a cross-section of one embodiment of the nano-composite having two nano-composite sub-layers.

[0028] Figure 22 illustrates a cross-section of one embodiment of the nano-porous non-woven having two nano-porous non-woven sub-layers and a support layer.

[0029] Figure 23 illustrates a cross-section of one embodiment of the nano-porous non-woven having two nano-porous non-woven sub-layers.

[0030] Figure 24 illustrates a cross-section of one embodiment of the nano-composite having five layers total.

[0031 ] Figure 25 illustrates a cross-section of one embodiment of the nano-porous non-woven.

[0032] Figure 26 illustrates a cross-section of the blend of the first polymer and the second polymer after extensional flow.

[0033] Figure 27 illustrates a cross-section of cross-lapped films forming a pre-consolidation formation.

[0034] Figure 28 illustrates a cross-section of a nano-composite.

[0035] Figure 29 illustrates a process flow diagram for forming a nano- porous non-woven. [0036] Figure 30 illustrates a cross-section of a nano-porous non-woven.

[0037] Figures 31 A and 31 B are SEMs of the nano-porous non-woven of Example 1 .

[0038] Figures 32A and 32B are SEMs of the nano-porous non-woven of Example 2.

[0039] Figures 33A and 33B are SEMs of the nano-porous non-woven of Example 3.

[0040] Figures 34A and 34B are SEMs of the nano-porous non-woven of Example 4.

[0041 ] Figure 35 is a graph showing DMA versus temperature for

Examples 1 -5.

[0042] Figure 36 is an SEM of the nano-porous non-woven of Example 6.

[0043] Figure 37 is an SEM of the nano-porous non-woven of Example 7.

[0044] Figure 38 is an SEM of the nano-porous non-woven of Example 8.

[0045] Figure 39 is an SEM of the nano-porous non-woven of Example 9.

[0046] Figures 40A and 40B are SEMs of the nano-porous non-woven of Example 10.

[0047] Figure 41 is an SEM of the nano-porous non-woven of Example

1 1 .

[0048] Figure 42 is an SEM of the nano-porous non-woven of Example

15.

[0049] Figure 43 is an SEM of the nano-porous non-woven of Example 19 having filtered Staphylococcus bacteria.

[0050] Figure 44 is an SEM of the nano-porous non-woven of Example 20 having filtered red blood cells.

[0051 ] Figure 45 is an SEM of the nano-porous non-woven of Example 20 having filtered rust particles. [0052] Figures 46A and 46B are SEMs of Example 21

[0053] Figures 47A-47D are SEMs of Example 23.

[0054] Figure 48 is an SEM of Example 24.

[0055] Figures 49 and 50 are SEMs of Example 28.

[0056] Figures 51 and 52 are SEMs of Example 30.

DETAILED DESCRIPTION

[0057] The present invention provides a process for creating a nano- composite having a matrix and nanofibers, where at least 70% of the nanofibers are fused to other nanofibers. The process may further contain a step to remove a portion or substantially all of the matrix material leaving the fused nanofibers as a nano-porous non-woven.

[0058] "Nanofiber", in this application, is defined to be a fiber having a diameter less than 1 micron. In certain instances, the diameter of the nanofiber is less than about 900, 800, 700, 600, 500, 400, 300, 200 or 100 nm, preferably from about 10 nm to about 200 nm. In certain instances, the nanofibers have a diameter from less than 1 00 nm. The nanofibers may have cross-sections with various regular and irregular shapes including, but not limiting to circular, oval, square, rectangular, triangular, diamond, trapezoidal and polygonal. The number of sides of the polygonal cross-section may vary from 3 to about 16.

[0059] "Non-woven" means that the layer or article does not have its fibers arranged in a predetermined fashion such as one set of fibers going over and under fibers of another set in an ordered arrangement.

[0060] As used herein, the term "thermoplastic" includes a material that is plastic or deformable, melts to a liquid when heated and freezes to a brittle, glassy state when cooled sufficiently. Thermoplastics are typically high molecular weight polymers. Examples of thermoplastic polymers that may be used include polyacetals, polyacrylics, polycarbonates, polystyrenes, polyolefins, polyesters, polyamides, polyaramides, polyamideimides, polyarylates, polyurethanes, epoxies, phenolics, silicones, polyarylsulfones, polyethersulfones, polyphenylene sulfides, polysulfones, polyimides, polyetherimides, polytetrafluoroethylenes, polyetherketones, polyether etherketones, polyether ketone ketones,

polybenzoxazoles, polyoxadiazoles, polybenzothiazinophenothiazines, polybenzothiazoles, polypyrazinoquinoxalines, polypyromellitimides,

polyquinoxalines, polybenzimidazoles, polyoxindoles, polyoxoisoindolines, polydioxoisoindolines, polytriazines, polypyridazines, polypiperazines, polypyridines, polypiperidines, polytriazoles, polypyrazoles, polycarboranes, polyoxabicyclononanes, polydibenzofurans, polyphthalides, polyacetals, polyanhydrides, polyvinyl ethers, polyvinyl thioethers, polyvinyl alcohols, polyvinyl ketones, polyvinyl halides, polyvinyl nitriles, polyvinyl esters, polysulfonates, polysulfides, polythioesters, polysulfones, polysulfonamides, polyureas, polyphosphazenes, polysilazanes, polypropylenes, polyethylenes, polyethylene terephthalates, polyvinylidene fluorides, polysiloxanes, or the like, or a combination comprising at least one of the foregoing thermoplastic polymers. In some embodiments, polyolefins include polyethylene, poly(a- olefin)s. As used herein, poly(a-olefin) means a polymer made by polymerizing an alpha-olefin. An a-olefin is an alkene where the carbon-carbon double bond starts at the a-carbon atom. Exemplary poly(a-olefin)s include polypropylene, poly(l-butene) and polystyrene. Exemplary polyesters include condensation polymers of a C2-12 dicarboxylic acid and a C2-12 alkylenediol. Exemplary polyamides include condensation polymers of a C^dicarboxylic acid and a C2-12 alkylenediamine, as well as polycaprolactam (Nylon 6).

[0061 ] One embodiment of a nano-porous non-woven 1 0 is shown in

Figure 1 . The nano-porous nonwoven 10 contains nanofibers 12 attached to one another. Figure 2 illustrates one embodiment of a nano-composite 20 containing the fused nanofibers 12 in the matrix 50.

[0062] The process shown in Figure 3 begins with Step 1 - blending a first polymer and a second polymer in a molten state. The first polymer forms discontinuous regions in the second polymer. These discontinuous regions may be nano-, micro-, or larger sized liquid drops dispersed in the second polymer. This blend may be cooled and reheated for the subsequent steps or moved directly into the following steps as a melted blend.

[0063] The thermoplastic polymer forming the nanofibers is referred herein as the first polymer. The thermoplastic polymer forming the matrix is referred herein as the second polymer. The matrix (second polymer) and the nanofibers (first polymer) may be formed of any suitable thermoplastic polymer that is melt-processable. The second polymer preferably is able to be removed by a condition to which the first polymer is not susceptible. The most common case is the second polymer is soluble in a solvent in which the first polymer is insoluble. "Soluble" is defined as the intermolecular interaction between polymer chain segment and solvent molecules are energetically favorable and caused polymer coils to expand and "insoluble" is defined as polymer-polymer self- interactions are preferred and the polymer coils will contract. Solubility is affected by temperature.

[0064] The solvent may be an organic solvent, water, an aqueous solution or a mixture thereof. Preferably, the solvent is an organic solvent. Examples of solvents include, but are not limited to, acetone, alcohol, chlorinated solvents, tetrahydrofuran, toluene, aromatics, dimethylsulfoxide, amides and mixtures thereof. Exemplary alcohol solvents include, but are not limited to, methanol, ethanol, isopropanol and the like. Exemplary chlorinated solvents include, but are not limited to, methylene chloride, chloroform, tetrachloroethylene, carbontetrachloride, dichloroethane and the like. Exemplary amide solvents include, but are not limited to, dimethylformamide, dimethylacetamide, N- methylpyrollidinone and the like. In another embodiment, the second polymer may be removed by another process such as decomposition. For example, polyethylene terephthalate (PET) may be removed with base (such as NaOH) via hydrolysis or transformed into an oligomer by reacting with ethylene glycol or other glycols via glycolysis, or nylon may be removed by treatment with acid. In yet another embodiment, the second polymer may be removed via

depolymerization and subsequent evaporation/sublimation of smaller molecular weight materials. For example, polymethyleneoxide, after deprotection, can thermally depolymerize into formaldehyde which subsequently

evaporates/sublimes away.

[0065] The first and second polymers are thermodynamically immiscible. Common miscibility predictors for non-polar polymers are differences in solubility parameters or Flory-Huggins interaction parameters. For polymers with nonspecific interactions, such as polyolefins, the Flory-Huggins interaction parameter may be calculated by multiplying the square of the solubility parameter difference by the factor (V/RT), where V is the molar volume of the amorphous phase of the repeated unit ν=Μ/Δ (molecular weight/density), R is the gas constant, and T is the absolute temperature. As a result, the Flory- Huggins interaction parameter between two non-polar polymers is always a positive number. Thermodynamic considerations require that for complete miscibility of two polymers in the melt, the Flory- Huggins interaction parameter has to be very small (e.g., less than 0.002 to produce a miscible blend starting from 100,000 weight-average molecular weight components at room

temperature). It is difficult to find polymer blends with sufficiently low interaction parameters to meet the thermodynamic condition of miscibility over the entire range of compositions. However, industrial experience suggests that some blends with sufficiently low Flory-Huggins interaction parameters, although still not miscible based on thermodynamic considerations, form compatible blends.

[0066] Preferably the viscosity and surface energy of the first polymer and the second polymer are close. Theoretically, a 1 :1 ratio would be preferred. If the surface energy and/or the viscosity are too dissimilar, nanofibers may not be able to form. In one embodiment, the second polymer has a higher viscosity than the first polymer.

[0067] The first polymer and second polymer may be selected from any thermoplastic polymers that meet the conditions stated above, are melt- processable, and are suitable for use in the end product. Suitable polymers for either the first or second polymer include, but are not limited to polyacetals, polyacrylics, polycarbonates, polystyrenes, polyolefins, polyesters, polyamides, polyaramides, polyamideimides, polyarylates, polyurethanes, epoxies, phenolics, silicones, polyarylsulfones, polyethersulfones, polyphenylene sulfides, polysulfones, polyimides, polyetherimides, polytetrafluoroethylenes,

polyetherketones, polyether etherketones, polyether ketone ketones,

polyquinoxalines, polybenzimidazoles, polyoxindoles, polyoxoisoindolines, polydioxoisoindolines, polytriazines, polypyridazines, polypiperazines, polypyridines, polypiperidines, polytriazoles, polypyrazoles, polycarboranes, polyoxabicyclononanes, polydibenzofurans, polyphthalides, polyacetals, polyanhydrides, polyvinyl ethers, polyvinyl thioethers, polyvinyl alcohols, polyvinyl ketones, polyvinyl halides, polyvinyl nitriles, polyvinyl esters, polysulfonates, polysulfides, polythioesters, polysulfones, polysulfonamides, polyureas, polyphosphazenes, polysilazanes, polypropylenes, polyethylenes, polyethylene terephthalates, polyvinylidene fluorides, polysiloxanes, or the like, or a combination comprising at least one of the foregoing thermoplastic polymers. In some embodiments, polyolefins include polyethylene, cyclic olefin copolymers (e.g. TOPAS ^®), poly(a-olefin)s. As used herein, poly(a-olefin) means a polymer made by polymerizing an alpha- olefin. An a-olefin is an alkene where the carbon-carbon double bond starts at the a-carbon atom. Examplary poly(a-olefin)s include polypropylene, poly(l-butene) and polystyrene. Exemplary polyesters include condensation polymers of a C2-12 dicarboxylic acid and a C2-12 alkylenediol. Exemplary polyamides include condensation polymers of a C2-12 dicarboxylic acid and a C2-12 alkylenediamine. Additionally, the first and/or second polymers may be copolymers and blends of polyolefins, styrene copolymers and terpolymers, ionomers, ethyl vinyl acetate, polyvinylbutyrate, polyvinyl chloride, metallocene polyolefins, poly(alpha olefins), ethylene- propylene-diene terpolymers, fluorocarbon elastomers, other fluorine-containing polymers, polyester polymers and copolymers, polyamide polymers and copolymers, polyurethanes, polycarbonates, polyketones, and polyureas, as well as polycaprolactam (Nylon 6).

[0068] In one embodiment, some preferred polymers are those that exhibit an alpha transition temperature (T_a) and include, for example: high density polyethylene, linear low density polyethylene, ethylene alpha-olefi^'n copolymers, polypropylene, poly(vinylidene fluoride), poly( vinyl fluoride), poly(ethylene chlorotrifluoroethylene), polyoxymethylene, poly(ethylene oxide), ethyl ene-vinyl alcohol copolymer, and blends thereof. Blends of one or more compatible polymers may also be used in practice of the invention. Particularly preferred polymers are polyolefins such as polypropylene and polyethylene that are readily available at low cost and may provide highly desirable properties in the microfibrous articles used in the present invention, such properties including high modulus and high tensile strength.

[0069] Useful polyamide polymers include, but are not limited to, synthetic linear polyamides, e.g., nylon-6, nylon-6,6, nylon-1 1 , or nylon-12. Polyurethane polymers which may be used include aliphatic, cycloaliphatic, aromatic, and polycyclic polyurethanes. Also useful are polyacrylates and polymethacrylates, which include, for example, polymers of acrylic acid, methyl acrylate, ethyl acrylate, acrylamide, methylacrylic acid, methyl methacrylate, n-butyl acrylate, and ethyl acrylate, to name a few. Other useful substantially extrudable hydrocarbon polymers include polyesters, polycarbonates, polyketones, and polyureas. Useful fluorine-containing polymers include crystalline or partially crystalline polymers such as copolymers of tetrafluoroethylene with one or more other monomers such as perfluoro(methyl vinyl)ether, hexafluoropropylene, perfluoro(propyl vinyl)ether; copolymers of tetrafluoroethylene with ethylenically unsaturated hydrocarbon monomers such as ethylene, or propylene.

[0070] Representative examples of polyolefins useful in this invention are polyethylene, polypropylene, polybutylene, poly 1 -butene, poly(3-methylbutene), poly(4-methylpentene) and copolymers of ethylene with propylene, 1 -butene, 1 - hexene, 1 -octene, 1 -decene, 4- methyl-1 -pentene and 1 -octadecene.

Representative blends of polyolefins useful in this invention are blends containing polyethylene and polypropylene, low-density polyethylene and high- density polyethylene, and polyethylene and olefin copolymers containing the copolymerizable monomers, some of which are described above, e.g., ethylene and acrylic acid copolymers; ethyl and methyl acrylate copolymers; ethylene and ethyl acrylate copolymers; ethylene and vinyl acetate copolymers-, ethylene, acrylic acid, and ethyl acrylate copolymers, and ethylene, acrylic acid, and vinyl acetate copolymers.

[0071 ] The thermoplastic polymers of the first and second polymers may include blends of homo- and copolymers, as well as blends of two or more homo- or copolymers. Miscibility and compatibility of polymers are determined by both thermodynamic and kinetic considerations. A listing of suitable polymers may also be found in PCT published application WO2008/028134, which is incorporated in its entirety by reference.

[0072] The thermoplastic polymers may be used in the form of powders, pellets, granules, or any other melt-processible form. The particular

thermoplastic polymer selected for use will depend upon the application or desired properties of the finished product. The thermoplastic polymer may be combined with conventional additives such as light stabilizers, fillers, staple fibers, antiblocking agents and pigments. The two polymers are blended while both are in the molten state, meaning that the conditions are such (temperature, pressure) that the temperature is above the melting temperature (or softening temperature) of both of the polymers to ensure good mixing. This is typically done in an extruder. The polymers may be run through the extruder more than once to ensure good mixing to create the discontinuous regions 31 formed from the first polymer in the matrix 50 of the second polymer as shown in Figure 4.

[0073] In one embodiment, the first polymer content of the first polymer / second polymer mixture is about 5% to about 90% by volume, preferably from 10% to about 70%vol, more preferably from 15% to about 60%vol, even more preferably from about 17% to about 50%vol. In another embodiment, the first and second polymers have a volume ratio from about 100:1 to about 1 :100, preferably, from about 40:1 to 1 :40, more preferably from about 30:1 to about 1 :30, even more preferably, from 20:1 to about 1 :20; still even more preferably from 10:1 to 1 :10; preferably from 3:2 to about 2:3. (4:1 , 1 :4) Preferably, the second polymer is the major phase comprising more than 50% by volume of the mixture.

[0074] Some preferred matrix (second polymer), nanofiber (first polymer), solvent combinations include, but are not limited to:

Matrix (second polymer) Nanofiber (first polymer) Solvent (for matrix)

Polymethyl methacrylate Polypropylene (PP) Toluene

(PMMA)

Cyclic olefin Copolymer PP Toluene

Cyclic Olefin copolymer Thermoplastic Toluene

Elastomer (TPE)

Cyclic Olefin Copolymer Polyethylene (PE) Toluene

Polystyrene (PS) Linear Low density Toluene

polyethylene (LLDPE)

Nylon 6 PP Formic Acid

Nylon 6 PE Formic Acid

PS Polyethylene Toluene

terephthalate (PET)

PET PP decomposition through hydrolysis

TPU (Thermoplastic PP Dimethyl formamide Polyurethane) (DMF)

TPU PE DMF

TPU Nylon DMF

polyvinyl alcohol) (PVA) PP Water

Cyclic olefin TPU Toluene PS TPU Toluene

Polycarbonate (PC) Nylon Toluene

PC PP Toluene

Polyvinyl chloride (PVC) PP Chloroform

Noryl (Polyphenyleneoxide PP Toluene

PPO and PS blend)

Noryl Nylon 6 Chloroform

Polyacrylonitrilebutadiene- Nylon 6 Hexane

styrene (ABS)

ABS PP Chloroform

PVC Nylon Benzene

Polybutyleneterephthalate PE trifluoroacetic acid (PBT)

[0075] In one embodiment, the second polymer is polystyrene and the first polymer could be linear low density polyethylene (LLDPE), high density polyethylene (HDPE), isotactic polypropylene (iPP), polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), poly(butylene adipate terephthalate) (PBAT), poly(Ethylene terephthalate-co- isophthalate)-poly(ethylene glycol) (IPET-PEG), and a highly modified cationic ion-dyeable polyester (HCDP).

[0076] In one embodiment, the matrix (second polymer) is a water vapor permeable material such as PEBAX resin, a block copolymer of nylon a polyether, by Arkema or water vapor permeable thermoplastic polyurethane (TPU). The nanofibers reinforce the nano-composite and also serve as a moisture barrier. When this nano-composite is laminated on a fabric via extrusion coating or calendaring, a breathable water proof fabric composite is created without the matrix material (second polymer) having to be removed.

[0077] In another embodiment, a third polymer may be added in Step 1 of Figure 3 where the first and second polymers are blended in the molten state. This third polymer is a thermoplastic that may be form additional nanofibers or additional matrix. The third polymer may be soluble or insoluble in the solvent that the second polymer is soluble in, depending on the desired end product. In one embodiment, the first and third polymers are insoluble in a solvent that the second polymer is soluble in. The amounts of polymers are selected such that the first and third polymers form nanofibers in a matrix of the second polymer. This second polymer may be partially or fully removed by the solvent. In another embodiment, the first polymer is insoluble in a solvent that the second polymer and the third polymer are soluble in. The amounts of polymers are selected such that the first polymer forms nanofibers in a matrix of the second polymer and the third polymer. The second and third polymers may be partially or fully removed by the solvent. In another embodiment, the second polymer is soluble in a first solvent, the third polymer is soluble in a second solvent, and the first polymer is insoluble in the first and second solvents. The amounts of polymers are selected such that the first polymer forms nanofibers in a matrix of the second polymer and the third polymer. This second and third polymer may be selectively removed by the first and/or second solvent.

[0078] In one embodiment, the nanofibers are core/shell nanofibers. The cores and shells may have any suitable thickness ratio depending on the end product. The core (formed from the first polymer) of the nanofiber extends the length of the nanofiber and forms the center of the nanofiber. The shell of the fiber at least partially surrounds the core of the nanofiber, more preferably surrounds approximately the entire outer surface of the core. Preferably, the shell covers both the length of the core as well as the smaller ends of the core. The shell polymer may be any suitable polymer, preferably selected from the listing of polymers for the first polymer and the second polymer.

[0079] The high surface area offered by nanofibers is a great platform for adding functional chemistries to form core/shell structured nanofibers which will either expand or enhance the favorable properties of the nanofibers such as the wetting behavior, catalytic behavior, release kinetics, and conductivity etc. These properties are potentially beneficial for applications like the storage and drug delivery of bioactive agents, catalyst support, tissue engineering, microelectronic and filtration etc.

[0080] Referring to Figure 5, there is shown nano-porous non-woven 10 containing a plurality of nanofibers 12 where at least 70% of the nanofibers are bonded to other nanofibers. The nanofibers 12 contain a core 121 and shell 123 the nanofibers are bonded to one another through the shell 123. The core 121 is typically the same as the first polymer used in the nanofibers. The shell 1 23 is formed from the third polymer. While cores and shells are shown in Figure 5 as having a one ratio of the thickness of the core to the shell, the thickness may vary based on polymers used and desired end product. Additionally, the fibers are shown touching and bonding for clarity, but may actually melt together where it would be difficult to determine where each of the individual fibers started and ended such as shown in Figure 6. In Figure 6, the third polymer is not present between the nanofibers where they are bonded to other nanofibers. Figure 7 illustrates having the nano-composite 20 with nanofibers 12 having a core 1 21 and a shell 123. The core of the nanofiber extends the length of the nanofiber and forms the center of the nanofiber. The shell of the fiber at least partially surrounds the core of the nanofiber; more preferably surrounds approximately the entire outer surface of the core. Preferably, the shell covers both the length of the core as well as the smaller ends of the core. The core polymer is preferably the first polymer. The core polymer and shell polymer in one embodiment are selected from the polymers listed as suitable for the first polymer.

[0081 ] At least a portion of the core polymer interpenetrates the shell of the nanofiber and at least a portion of the shell polymer interpenetrates the core of the nanofiber. This occurs as the core and shell polymers are heated and formed together. The polymer chains from the core polymers interpenetrate the shell and the polymer chains from the shell polymer interpenetrate the core and the core and shell polymers intermingle. This would not typically occur from a simple coating of already formed nanofibers with a coating polymer.

[0082] In one embodiment, the matrix polymer is polystyrene and the core polymer could be linear low density polyethylene (LLDPE), high density polyethylene (HDPE), isotactic polypropylene (iPP), polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), poly(butylene adipate terephthalate) (PBAT), poly(Ethylene terephthalate-co- isophthalate)-poly(ethylene glycol) (IPET-PEG), and a highly modified cationic ion-dyeable polyester (HCDP).

[0083] The core and shell polymers may be chosen with to have a different index of refraction or birefringence for desired optical properties. In another embodiment, the core polymer is soluble in a second solvent (which may be the same solvent or different solvent as the first solvent) such that the core of the core/shell nanofibers may be removed leaving bonded hollow nanofibers.

[0084] One process to form the nano-porous non-woven 10 begins with blending the core polymer (first polymer), the shell polymer (third polymer), and the matrix polymer (second polymer) in a molten state. The core polymer forms discontinuous regions 31 in the matrix polymer 50 in Figure 4 with the shell polymer moving to the interface between the core polymer and the matrix polymer. The shell polymer at least partially surrounds the core polymer and preferably completely encapsulates the core polymer. These discontinuous regions may be nano-, micro-, or larger sized liquid drops dispersed in the matrix polymer. This blend may be cooled or used directly in the next processing step. The core and shell polymers are insoluble in the first solvent and the core polymer and shell polymer are not miscible. The process continues as per Figure 3.

[0085] In another embodiment, a third component, reactive or non- reactive, such as a compatiblizer, a blooming agent, or a co-polymer may be add in the system so at least part of it migrates to the interface between the first and second polymer in the first intermediate. Such a third component may be selected to be partially soluble or insoluble in the second solvent. This third component will be exposed on the surface of the first polymer after etching. Via further chemistry, the third component surface of the first polymer may have added functionality (reactivity, catalytically functional, conductivity, chemical selectivity) or modified surface energy for certain applications. For example, in a PS/PP system (second polymer/first polymer), PP-g-MAH (maleated PP) or PP- g-PS, styrene/ ethylene-butylene/ styrene (SEBS) may be added to the system. The added MAH and the styrene functional groups may be further reacted to add functionality to the nano-composite or nano-porous non-woven.

[0086] The nanofibers may have a gradient of different materials from the core of the nanofibers to the surface of the nanofiber. Figure 8 shows an enlargement of the nano-porous non-woven 10 illustrating the bulk area 122 and surface area 1 24 of each of the nanofibers 12 and how the nanofibers are bonded to one another. The concentration in the gradient nanofibers is of different materials from the surface area 124 to the bulk area 1 22. The shading of Figure 8 is to illustrate the concentration gradient. The majority of the surface area 124 of the nanofiber 12 is the third component. The majority of the bulk area 122 of the nanofiber 12 is the first polymer. The third component is in a gradient along the radius of the nanofiber 12 with the highest concentration being at the surface area 124 of the nanofiber 12 and the lowest concentration of the third component being at the bulk area 122 of the nanofiber 12.

[0087] In one embodiment, the third component is a lubricant. The third component being a lubricant would help control the release properties of the nanofibers and non-woven. The third component being a lubricant also allows the nanofibers to more easily move across each other during consolidation giving better randomization. A lubricant could also alter the mechanical properties of the final non-woven structure.

[0088] In another embodiment, the third component is a molecule (or polymer) that contains reactive sites. This creates a nano-porous non-woven with at least 70% of the nanofibers bonded to other nanofibers, where the nanofibers can be further reacted for additional functionality.

[0089] Another example would be the use of homopolypropylene and hyperbranched polymer grafted polypropylene (PP-HBP). The PP-HBP can be obtained by reacting Maleic anhydride grafted polypropylene with a

hyperbranched polymer such as Boltorn E2 by Perstorp and functions as the third component with the homopolypropylene as the bulk polymer. Nylon 6 or another suitable polymer may be used as the matrix material. This combination of the materials would result in a product that provides controlled multifunctional surfaces for protective coatings, energetic materials, electronic, optoelectronics, sorbent, sensing, and repel/release applications. Another example would be the use of propylene maleic anhydride co-polymer as the third component. In combination with polypropylene as the bulk (first) polymer and polystyrene as the matrix polymer, the resultant nano-porous non-woven would contain bonded polypropylene nanofibers having modified surface energy. This could affect the improve bonding or further processing of the non-woven.

[0090] Small molecules that either insoluble or partially soluble in the bulk polymer will diffuse, e.g., bloom to the surface of the polymer. The rate at which the molecule blooms can be controlled by temperature, concentration, humidity etch depending on the specifics of the molecule and the bulk (first) polymer properties. The controlled blooming additive can gives the bulk polymer controlled release property or provides the polymer surface with functional properties such as antistatic, hydrophilic, hydrophobic, flame retardant, colorant, anti-scratch, conductive, and antimicrobial properties. The bloomed small molecules may create a self-cleaning filter material that would resist biofouling; selective adsorption of an analyte of interest (for example as a headspace gas chromatography sample material); and delivery of a scent or aroma.

[0091 ] In one embodiment, any layer of the nano-composite and/or nano- porous non-woven may contain any suitable particle, including nano-particles, micron-sized particles or larger. "Nano-particle" is defined in this application to be any particle with at least one dimension less than one micron. The particles may be, but are not limited to, spherical, cubic, cylindrical, platelet, and irregular. Preferably, the nano-particles used have at least one dimension less than 800 nm, more preferably less than 500 nm, more preferably, less than 200 nm, more preferably less than 1 00 nm. The particles may be organic or inorganic.

[0092] Figure 9 illustrates one embodiment of a nano-porous non-woven 10 which contains a plurality of nanofibers 12 and a plurality of particles 60. At least 70% of the nanofibers 12 are fused to other nanofibers 12 within the nano- porous non-woven 10. Preferably, the particles 60 are nano-particles. At least 50% of the particles 60 are positioned adjacent a surface of the nanofibers 12. This means that the resultant non-woven produced would contain particles 60 stuck, adhered, or otherwise attached to the nanofibers 12 so that they would not simply fall out of the nano-porous non-woven 10. In another embodiment, at least 70% of the particles 60 are positioned adjacent a surface of the nanofibers 12, more preferably at least 80%. The particles 60 may be entrapped in the nano-porous non-woven 10 due to the small size of the holes in the non-woven 10. Figure 10 illustrates one embodiment of a nano-composite 20 which contains a plurality of nanofibers 12 and a plurality of particles 60 in a matrix 50.

[0093] Examples of suitable organic particles include

buckminsterfullerenes (fullerenes), dendrimers, organic polymeric nanospheres, aminoacids, and linear or branched or hyperbranched "star" polymers such as 4, 6, or 8 armed polyethylene oxide with a variety of end groups, polystyrene, superabsorbing polymers, silicones, crosslinked rubbers, phenolics, melamine formaldehyde, urea formaldehyde, chitosan or other biomolecules, and organic pigments (including metallized dyes).

[0094] Examples of suitable inorganic particles include, but are not limited to, calcium carbonate, calcium phosphate (e.g., hydroxy-apatite), talc, mica, clays, metal oxides, metal hydroxides, metal sulfates, metal phosphates, silica, zirconia, titania, ceria, alumina, iron oxide, vanadia, antimony oxide, tin oxide, alumina/silica, zirconium oxide, gold, silver, cadmium selenium, chalcogenides, zeolites, nanotubes, quantum dots, salts such as CaC0₃, magnetic particles, metal-organic frameworks, and any combinations thereof.

[0095] In one embodiment, the particles are further functionalized. Via further chemistry, the third surface of the particles may have added functionality (reactivity, catalytically functional, electrical or thermal conductivity, chemical selectivity, light absorbtion) or modified surface energy for certain applications.

[0096] In another embodiment, particles are organic-inorganic, coated, uncoated, or core-shell structure. In one embodiment, the particles are PEG (polyethylene glycol) coated silica, PEG coated iron oxide, PEG coated gold, PEG coated quantum dots, hyperbranched polymer coated nano-clays, or other polymer coated inorganic particles such as pigments. The particles, in one embodiment, may melt and re-cool in the process of forming the nano-porous non-woven. The particles may also be an inorganic core -inorganic shell, such as Au coated magnetic particles. The particles, in one embodiment, may melt and re-cool in the process of forming the nano-porous non-woven. In another embodiment, the particles are ZELEC^®, made by Milliken and Co. which has a shell of antimony tin oxide over a core that may be hollow or solid, mica, silica or titania. A wax or other extractible coating (such as functionalized copolymers) may cover the particles to aid in their dispersion in the matrix polymer.

[0097] The process of forming the nano-porous non-woven (Figure 9) and the nano-composite (Figure 10) with the optional nano-particles begins with blending a first polymer and a second polymer in a molten state along with particles. The process continues as per Figure 3.

[0098] In another embodiment, the nano-composite 20 and/or nano- porous non-woven 10 contains at least one textile layer which may be any suitable textile layer. The textile layer may be on one or both sides of the nano- composite, or between some layers of the nano-composite. If more than one textile layer is used, they may each contain the same or different materials and constructions. In one embodiment, the textile layer is selected from the group consisting of a knit, woven, non-woven, and unidirectional layer. The textile layer provides turbulence of the molten mixture of the first and second polymer during extrusion and/or subsequent consolidation causing nanofiber movement, randomization, and bonding. The textile layer may be introduced into the process in Step 4 of Figure 3 or the blend of the first and second polymer in Step 1 of Figure 3 may be extruded directly onto the textile layer.

[0099] Referring to Figure 1 1 , there is shown one embodiment of a nano- porous non-woven 10 with a textile layer 40. The nano-porous non-woven 1 0 is located on a textile layer 40. In the nano-porous non-woven 10, the first side 10a is located at the surface of the nano-porous non-woven 10 adjacent the textile layer 40. The second side 1 0b is located on surface of the nano-porous non-woven 10 opposite the first side 10a. The nano-porous non-woven 10 contains a plurality of the nanofibers 12. At least some of the nanofibers 12 from the nano-porous non-woven 1 0 penetrate and embed into at least a portion of the textile layer 40 thickness. The nanofibers 12 are formed from the first polymer.

[00100] The penetration of the nanofibers 1 2 from the nano-porous non- woven 10 into the textile layer 40 is more clearly shown in Figure 12 which is an enlarged view of Figure 1 1 showing the yarns 41 of textile layer 40. In another embodiment, the penetration of the nanofibers 12 from the nano-porous non- woven 10 into the textile layer 40 may be completely through the yarns 41 of the textile layer 40 as shown in Figure 13.

[00101 ] Figure 14 illustrates another embodiment of a nano-composite 20 containing the nano-porous non-woven 10, a matrix 50, and a textile layer 40. The matrix 50 at least partially encapsulating the nanofibers 12 and is formed from the second polymer. At least some of the nanofibers 12 from the nano- porous non-woven 10 penetrate and embed into at least a portion of the textile layer 40 thickness. The nano-composite 20 containing the matrix and the textile layer 40 may be used as a final product or as an intermediate product in the process. [00102] The textile layer 40 may be formed from any suitable fibers and/or yarns including natural and man-made. Woven textiles can include, but are not limited to, satin, twill, basket-weave, poplin, and crepe weave textiles. Jacquard woven textiles may be useful for creating more complex electrical patterns. Knit textiles can include, but are not limited to, circular knit, reverse plaited circular knit, double knit, single jersey knit, two-end fleece knit, three-end fleece knit, terry knit or double loop knit, warp knit, and warp knit with or without a micro denier face. The textile may be flat or may exhibit a pile. The textile layer may have any suitable coating upon one or both sides, just on the surfaces or through the bulk of the textile. The coating may impart, for example, soil release, soil repel/release, hydrophobicity, and hydrophilicity.

[00103] As used herein yarn shall mean a continuous strand of textile fibers, spun or twisted textile fibers, textile filaments, or material in a form suitable for knitting, weaving, or otherwise intertwining to form a textile. The term yarn includes, but is not limited to, yarns of monofilament fiber,

multifilament fiber, staple fibers, or a combination thereof. The textile material may be any natural or man-made fibers including but not limited to man-made fibers such as polyethylene, polypropylene, polyesters (polyethylene

terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polylactic acid, and the like, including copolymers thereof), nylons (including nylon 6 and nylon 6,6), regenerated cellulosics (such as rayon), elastomeric materials such as Lycra™, high-performance fibers such as the polyaramids, polyimides, PEI, PBO, PBI, PEEK, liquid-crystalline, thermosetting polymers such as melamine-formaldehyde (BASOFIL™) or phenol-formaldehyde

(KYNOL™), basalt, glass, ceramic, cotton, coir, bast fibers, proteinaceous materials such as silk, wool, other animal hairs such as angora, alpaca, or vicuna, and blends thereof.

[00104] In one embodiment, a second textile layer is located on the second side 10b of the nano-porous non-woven 10. This second textile layer may be of any suitable construction and materials. It may have the same or different construction and materials as the first textile layer.

[00105] In one embodiment, the nano-porous non-woven may be formed having polypropylene nanofibers combined with a woven nylon textile layer. It has been shown that a textile layer having desired fluid transport properties may be formed by using this combination of layers and materials.

[00106] In another embodiment, an additional nano-porous non-woven is located on the second side 10b of the (first) nano-porous non-woven 10. This second nano-porous non-woven may be of any suitable construction and materials described above in regards to the first nano-porous non-woven. It may have the same or different construction and materials as the first nano-porous non-woven.

[00107] In another embodiment, sacrificial layers may be added at any suitable location throughout the nano-porous non-woven and/or nano-composite. In one embodiment, there is a sacrificial layer on the textile layer on the side opposite to the nano-porous non-woven and/or nano-composite. The thickness of the sacrificial layer and processing conditions can tailor the depth that the nanofibers and matrix penetrate into the textile layer. In another embodiment, a sacrificial layer may be placed on the second side of the nano-porous non- woven. If the sacrificial layer is co-extruded with the nano-composite it may decrease the edge effects of extruding or otherwise forming the nano-composite (using the first and second polymer) so that the size and density of the nanofibers is more even across the thickness (from the first side to the second side) of the nano-porous non-woven and/or nano-composite. The sacrificial layer on the second side of the nano-porous non-woven may also help improve processing conditions.

[00108] In another embodiment, the nano-composite further comprises a support layer which may be one at least one side of the nano-composite. The nano-composite and supporting layer may formed together, preferably through co-extrusion or attached together at a later processing step. If the supporting layer is co-extruded, then the supporting layer contains the supporting polymer which may be any suitable thermoplastic that is co-extrudable which the choice of first polymer and second polymer. The molten polymer blend of the first and second polymer is, in one embodiment, co-extruded with at least one supporting layer being subjected to extensional flow and shear stress such that the first polymer forms nanofibers within the matrix of the second polymer. The extensional flow and shear stress may be from, for example, extrusion through a slit die, a blown film extruder, a round die, injection molder, or a fiber extruder. These materials may then be subsequently drawn further in either the molten or softened state.

[00109] Referring to Figure 15, there is shown one embodiment of a nano- composite 1 0 with a supporting layer 70. The nano-composite 20 is located on a supporting layer 70 and contains nanofibers 12 in a matrix 50. The nano- composite 20 and the supporting layer 70 are formed at the same time from molten or softened polymers, preferably by co-extrusion. In the nano-composite 20, the first outer boundary 20a is located at the surface of the nano-composite 20 adjacent the supporting layer 70. The second outer boundary 20b is located on surface of the nano-composite opposite the first outer boundary 20a. The inner boundary 20c is located at the mid-point plane between the first outer boundary layer 20a and the second outer boundary layer 20b. The inner boundary 20c is not a physical boundary, but an imaginary plane in the bulk of the nano-composite 20. The nanofibers 12 within the nano-composite 20 have a substantially uniform fiber size and density from the inner boundary 20c to the first outer boundary 20a. Moving from the inner boundary 20c to the second outer boundary layer 20b the size of the nanofibers decreases and the density of the nanofibers increases.

[001 10] The supporting polymer 71 of the supporting layer 70 may be selected from the listing of possible thermoplastic polymers listed for the first polymer and the second polymer. In one embodiment, the supporting polymer is the same polymer as the second polymer or is soluble in the same solvent as the second polymer. This allows the matrix (second polymer) and the supporting layer (which is a sacrificial layer) to be removed at the same time leaving just the nanofibers in the nano-porous non-woven layer. In another embodiment, the supporting polymer is a different polymer than the second polymer and is not soluble in the same solvents as the second polymer. This produces a nano- composite on the supporting layer after removing the second polymer which is advantageous for applications that require a non-woven having increased dimensional stability and strength. The supporting layer decreases the edge effects of extruding or otherwise forming the nano-porous non-woven and/or nano-composite so that the size and density of the nanofibers is more even across the thickness (from the first side to the second side) of the nano-porous non-woven and/or nano-composite.

[001 1 1 ] The supporting layer thickness may be tuned to create the described concentration gradient or lack thereof in the resultant nano-porous non-woven 10. The supporting layer 70 may also contain any other suitable material including but not limited to nanofibers, micron sized fibers, nano- particles, conductive particles, flame retardants, supporting structures such as scrims, and antimicrobials.

[001 12] When the matrix 50 (second polymer) is removed from the nano- composite 20 shown in Figure 15, what remains is a nano-porous non-woven 1 0 and a supporting layer 70 as shown in Figure 16. In the nano-porous non-woven 10, the first outer boundary 10a is located at the surface of the nano-porous non- woven 10 adjacent the supporting layer 70. The second outer boundary 1 0b is located on surface of the nano-porous non-woven 10 opposite the first outer boundary 10a. The inner boundary 10c is located at the mid-point plane between the first outer boundary layer 10a and the second outer boundary layer 10b. The inner boundary 10c is not a physical boundary, but an imaginary plane in the bulk of the nano-porous non-woven 10. The nanofibers 12 within the nano-porous non-woven 1 0 have a substantially uniform fiber size and density from the inner boundary 1 0c to the first outer boundary 10a. Moving from the inner boundary 10c to the second outer boundary layer 10b the size of the nanofibers decreases and the density of the nanofibers increases. Structure shown in Figure 16 may be used for any suitable purpose including facial oil absorption.

[001 13] In a facial oil absorption application, the nano-porous non-woven

10 absorbs the oil efficiently because of the small diameter of the fibers, the bonding of the nanofibers 12 within the nano-porous non-woven 10 increases the durability, and the supporting layer 70 provides strength and support for the nano-porous non-woven 1 0. When oil is absorbed by the nano-porous non- woven 10, the nano-porous non-woven 10 may change from white or opaque to translucent or transparent as the oil has a much closer index of refraction to the thermoplastic nanofibers than the air the oil replaced. This color or transparency change can indicate to users that the wipe has absorbed oil and may be nearing its maximum oil absorption amount.

[001 14] When the matrix 50 (second polymer) and the supporting layer 70 are removed from the structure shown in Figure 1 5, the nano-porous non-woven 10 shown in Figure 1 7 remains. The nanofibers 12 within the nano-porous non- woven 10 have a substantially uniform fiber size and density from the inner boundary 10c to the first outer boundary 10a. Moving from the inner boundary 10c to the second outer boundary layer 10b the size of the nanofibers decreases and the density of the nanofibers increases.

[001 15] Figure 18 illustrates an embodiment where the nano-composite 20 is surrounded on both sides by supporting layers 70. Having supporting layers 70 on both sides of the nano-composite 20 creates a more uniform distribution (of in both concentration and size) of nanofibers 12 across the entire thickness of the nano-composite 20 (from 20a to 20b). Each supporting layer 70 may contain different supporting polymers 71 and/or different additives or amounts of additives.

[001 16] In one embodiment, only one of the supporting layers 70 contain a supporting polymer 71 that is the same polymer as the matrix 50 or is soluble in the same solvent as the matrix 50. This allows the matrix (second polymer) 50 and one of the supporting layers 70 (a sacrificial layer) to be removed at the same time leaving a nano-porous non-woven 10 on one supporting layer 70. In another embodiment, both of the supporting layers 70 contain a supporting polymer 71 contains the same polymer as the matrix 50 or is soluble in the same solvent as the matrix 50. This allows the matrix (second polymer) 50 and both of the supporting layers 70 to be removed at the same time leaving a nano-porous non-woven 10. In another embodiment, the supporting polymers 71 of the supporting layers 70 are both a different polymer than the matrix 50 and are not soluble in the same solvents as the matrix 50. This produces a nano-porous non-woven 10 sandwiched by two supporting layers 70 after removing the matrix 50.

[001 17] When the matrix 50 (second polymer) is removed from the structure shown in Figure 18, the structure shown in Figure 1 9 remains. The nano-porous non-woven 10 is surrounded on both sides by supporting layers 70. The nanofibers 12 within the nano-porous non-woven 10have a substantially uniform fiber size and density from the first outer boundary 10a to the second outer boundary 1 0b.

[001 18] When the matrix 50 (second polymer) and the supporting layers 70 are removed from the structure shown in Figure 4, the nano-porous non-woven 10 shown in Figure 20 remains. The nanofibers 12 within the nano-porous non- woven 10 have a substantially uniform fiber size and density from the first outer boundary 10a to the second outer boundary 1 0b.

[001 19] In some embodiments, the nano-composite 20 contains multiple sub-layers. The nano-composite 20 may contain any suitable number of sublayers including 2, 3, 4, or more sub-layers. The nano-composite 20 shown in Figure 21 has two sub-layers 21 and 23. Each of the sub-layers may contain the same or different first polymer, second polymer, concentrations of the first and second polymer, and/or additives. This thicknesses of the sub-layers may also be the same or different. Multiple sub layers can be beneficial to many applications, such as battery separators for lithium ion batteries where both mechanical strength and fast shutdown speed are achieved by different layers, each having differing filter characteristics. When the matrix 50 is removed from all of the sub-layers 21 , 23 of the nano-composite 20, the structure containing nano-porous non-woven 1 0 as shown in Figure 22 remains. When the matrix 50 of the sub-layers 21 , 21 of the nano-composite 20 shown in Figure 21 and the supporting polymer 21 0 of the supporting layer 200 is removed, the nano-porous non-woven 10 as shown in Figure 23 remains. Figure 23 shows two sub-layers 1 1 and 13 of the nano-porous non-woven 10. A layer with different

concentrations of polymer could also have different degrees of porosity and pore sizes within this layer. Materials, such as this, containing pore size gradients have been shown to give superior behavior as filtration membranes.

[00120] Figure 24 illustrates a five (5) composite. The layers are, in order, a textile material 40, a nano-composite 20, a supporting layer 70, a nano- composite 20, and a textile material 400. When the supporting layer 70 and the matrix 50 are removed, two nano-porous non-wovens 10 on textile layers 40 remain as shown in Figure 25. The composite may contain any suitable number of total layer, nano-composite layers, nano-porous non-woven layers, supporting layers, and textile materials in any suitable configuration.

[00121 ] Referring back to Figure 3, the next step (step 2), the molten polymer blend is subjected to extensional flow and shear stress such that the first polymer forms nanofibers. The nanofibers formed have an aspect ratio of at least 5:1 (length to diameter), more preferably, at least 1 0:1 , at least 50:1 , at least 100:1 , and at least 1000:1 . The nanofibers are generally aligned along an axis, referred to herein as the "nanofiber axis". Preferably, at least 80% of the nanofibers are aligned within 20 degrees of this axis. After the extensional flow less than 30% by volume of the nanofibers are bonded to other nanofibers. This means that at least 70% of the nanofibers are not bond (adhered or otherwise) to any other nanofiber. Should the matrix (second polymer) by removed at this point, the result would be mostly separate individual nanofibers. In another embodiment, after step 200, less than 20%, less than 10%, or less than 5% of the nanofibers are bonded to other nanofibers. Figure 26 illustrates a cross- section of the polymer blend after the extensional forces of step 2. As may be seen, most of the unattached fibers 1 9 in the matrix 50 are aligned in a single direction and are not bonded to other nanofibers.

[00122] In one embodiment, the mixing of the first and second polymers (Step 1 ) and the extension flow (Step 2) may be performed by the same extruder, mixing in the barrel of the extruder, then extruded through the die or orifice. The extensional flow and shear stress may be from, for example, extrusion through a slit die, a blown film extruder, a round die, injection molder, or a fiber extruder.

[00123] In Step 3 of Figure 3, the molten polymer blend is cooled to a temperature below the softening temperature of the first polymer to preserve the nanofiber shape. "Softening temperature" is defined to be the temperature where the polymers start to flow. For crystalline polymers, the softening temperature is the melting temperature. For amorphous polymers, the softening temperature is the Vicat temperature. This cooled molten polymer blend forms the first intermediate.

[00124] Next, the first intermediate is formed into a pre-consolidation formation in Step 4 of Figure 3. Forming the first intermediate into a pre- consolidation formation involves arranging the first intermediate into a form ready for consolidation. The pre-consolidation formation may be, but is not limited to, a single film, a stack of multiple films, a fabric layer (woven, non-woven, knit, unidirectional), a stack of fabric layers, a layer of powder, a layer of polymer pellets, an injection molded article, or a mixture of any of the previously mentioned. The polymers in the pre-consolidation formation may be the same through the layers and materials or vary.

[00125] In a first embodiment, the pre-consolidation formation is in the form of a fabric layer. In this embodiment, the molten polymer blend is extruded into fibers which form the first intermediate. The fibers of the first intermediate are formed into a woven, non-woven, knit, or unidirectional layer. This fabric layer may be stacked with other first intermediate layers such as additional fabric layers or other films or powders.

In a second embodiment, the pre-consolidation formation is in the form of a film layer 210 in Figure 26. In this embodiment, the molten polymer blend is extruded into a film which forms the first intermediate. The film may be stacked with other films or other first intermediate layers. The film may be consolidated separately or layered with other films. In one embodiment, the films are stacked such that the nanofiber axes all align. In another embodiment, shown in Figure 27, the films 210 are cross-lapped such that the nanofiber 19 axis of one film is perpendicular to the nanofiber 19 axes of the adjacent films forming the pre- consolidation formation 410. If two or more films are used, they may each contain the same or different polymers. For example, a PP/PS 80%/20%wt film may be stacked with a PP/PS 75%/25%wt film. Additionally, a PE/PS film may be stacked on a PP/PS film. Other angles for cross-lapping may also be employed.

[00126] In a third embodiment, the pre-consolidation formation is in the form of a structure of pellets, which may be a flat layer of pellets or a three- dimensional structure. In this embodiment, the molten polymer blend is extruded into a fiber, film, tube, elongated cylinder or any other shape and then is pelletized which forms the first intermediate. Pelletizing means that the larger cooled polymer blend is chopped into finer components. The most common pelletizing method is to extrude a pencil diameter fiber, then chop the cooled fiber into pea-sized pellets. The pellets may be covered or layered with any other first intermediate structures such as fabric layers or film layers.

[00127] In a fourth embodiment, the pre-consolidation formation is in the form of a structure of a powder, which may shaped into be a flat layer of powder or a three-dimensional structure. In this embodiment, the molten polymer blend is extruded, cooled, and then ground into a powder which forms the first intermediate. The powder may be covered or layered with any other first intermediate structures such as fabric layers or film layers.

[00128] In a fifth embodiment, the pre-consolidation formation is in the form of a structure of an injection molded article. The injection molded first intermediate may be covered or layered with any other first intermediate structures such as fabric layers or film layers.

[00129] Additionally, the pre-consolidation formation may be layered with other layers (not additional first intermediates) such as fabric layers or other films not having nanofibers or embedded into additional layers or matrixes. One such example would be to embed first intermediate pellets into an additional polymer matrix. The pre-consolidation layer may also be oriented by stretching in at least one axis.

[00130] In the next step, Step 5 of Figure 3, consolidation is conducted at a temperature is above the T_g and of both the first polymer and second polymer and within 50 degrees Celsius of the softening temperature of first polymer. More preferably, consolidation is conducted at 20 degrees Celsius of the softening temperature of the first polymer. The consolidation temperature upper limit is affected by the pressure of consolidation and the residence time of consolidation. For example, a higher consolidation temperature may be used if the pressure used is high and the residence time is short. If the consolidation is conducted at a too high a temperature, too high a pressure and/or too long a residence time, the fibers might melt into larger structures or revert back into discontinuous or continuous spheres.

[00131 ] Consolidating the pre-consolidation formation causes nanofiber movement, randomization, and at least 70% by volume of the nanofibers to fuse to other nanofibers. This forms the second intermediate. This movement, randomization, and bonding of the nanofibers may be accomplished two ways.

On being that the pre-consolidation formation contains multiple nanofiber axes.

This may arise, for example, from stacking cross-lapped first intermediate layers or using a non-woven, or powder. When heat and pressure is applied during consolidation, the nanofibers move relative to one another and bond where they interact. Another method of randomizing and forming the bonds between the nanofibers is to use a consolidation surface that is not flat and uniform. For example, if a textured surface or fabric were used, even if the pressure was applied uniformly, the flow of the matrix and the nanofibers would be turbulent around the texture of the fabric yarns or the textured surface causing

randomization and contact between the nanofibers. If one were to simply consolidate a single layer of film (having most of the nanofibers aligned along a single nanofiber axis) using a press that delivered pressure perpendicular to the plane of the film, the nanofibers would not substantially randomize or bond and once the matrix was removed, predominately individual (unattached) nanofibers would remain.

[00132] In pre-consolidation formations such as powders or pellets the nanofiber axes are randomized and therefore a straight lamination or press would produce off-axis pressure. If the first intermediate of Figure 26 were used as the pre-consolidation formation and was pressured using a carver press (pressure would be perpendicular to the nanofiber axis, 70% of the nanofibers would not bond to one another. The pre-consolidation formation of Figure 27, when consolidated, would bond at least 70% of the nanofibers to one another. The temperature, pressure, and time of consolidation would move the nanofibers between the first intermediate layers 21 0 causing randomization and bonding of the nanofibers. Preferably, at least 75%vol of the nanofibers to bond to other nanofibers, more preferably at least 85%vol, more preferably at least 90%vol, more preferably at least 95%vol, more preferably at least 98%vol. Consolidation forms the second intermediate, also referred to as the nano-composite.

[00133] At applied pressure and temperature, the second polymer is allowed to flow and compress resulting in bringing "off-axis" nanofibers to meet at the cross over points and fuse together. Additional mixing flow of the second polymer may also be used to enhance the mixing and randomization of the off- axis fibers. One conceivable means is using a textured non-melting substrate such as a fabric (e.g. a non-woven), textured film, or textured calendar roll in consolidation. Upon the application of pressure, the local topology of the textured surface caused the second polymer melt to undergo irregular fluctuations or mixing which causes the direction of the major axis of the nanofibers to alter in plane, resulting in off-axis consolidations. In a straight lamination or press process, due to the high melt viscosity and flow velocity, the flow of the second polymer melt is not a turbulent flow and cross planar flow is unlikely to happen. When the majority of the nanofibers are in parallel in the same plane, the nanofibers will still be isolated from each other, resulting in disintegration upon etching.

[00134] The second intermediate (also called nano-composite 20) contains the nanofibers 12 formed from the first polymer, where at least 70%vol of the nanofibers are bonded to other nanofibers in a matrix 50 of the second polymer and is shown in Figure 28. This nano-composite may be used, for example, in reinforcement structures, or a portion or the entire second polymer may be removed.

[00135] Figure 29 illustrates an additional Step 6 (as compared to Figure 3) of dissolving at least a portion of the second polymer from the nano-composite. A small percentage (less than 30%vol) may be removed, most, or all of the second polymer may be removed. If just a portion of the second polymer is removed, it may be removed from the outer surface of the intermediate leaving the nano-composite having a nano-porous non-woven surrounding the center of the article which would remain a nano-composite. The removal may be across one or more surfaces of the nano-composite 20 or may be done pattern-wise on the nano-composite 20. Additionally, the matrix 50 may be removed such that there is a concentration gradient of the second polymer in the final product with the concentration of the second polymer the lowest at the surfaces of the final product and the highest in the center. The concentration gradient may also be one sided, with a concentration of the second polymer higher at one side. [00136] If essentially the entire or the entire second polymer is removed from the second intermediate, what remains is a nano-porous non-woven 10 shown in Figure 30, where at least 70%vol of the nanofibers are bonded to other nanofibers. While the resultant structure is described as a nano-porous non- woven, the resultant structure may consist of a non-woven formed from bonded nanofibers and resemble a non-woven more than a film. The bonding between the nanofibers 12 provides physical integrity for handling of the etched films/non- woven in the etching process which makes the use of a supporting layer optional. Smearing and/or tearing of the nanofibers upon touching is commonly seen in the poorly consolidated nano-porous non-wovens. The second polymer may be removed using a suitable solvent or decomposition method described above.

[00137] The benefit of the process of consolidating the pre-consolidation layer is the ability to form the bonds between the nanofibers without losing the nanofiber structure. If one were to try to bond the nanofibers in a nano-porous non-woven, when heat is applied, the nanofibers would all melt together and the nanofibers would be lost. This would occur when the heat is uniform, such as a lamination or nip roller, or is specific such as spot welding or ultrasonics.

[00138] In one embodiment, the nano-composite 20 and/or the nano- porous non-woven 10 may contain additional microfibers and/or engineering fibers. Engineering fibers are characterized by their high tensile modulus and/or tensile strength. Engineering fibers include, but are not limited to, E-glass, S- glass, boron, ceramic, carbon, graphite, aramid, poly(benzoxazole), ultra high molecular weight polyethylene (UHMWPE), and liquid crystalline thermotropic fibers. The use of these additional fibers in the composites and non- wovens/films may impart properties that maynot be realized with a single fiber type. For example, the high stiffness imparted by an engineering fiber may be combined with the low density and toughness imparted by the nanofibers. The extremely large amount of interfacial area of the nanofibers may be effectively utilized as a means to absorb and dissipate energy, such as that arising from impact. In one embodiment a nanofibers mat comprised of hydrophobic nanofibers is placed at each of the outermost major surfaces of a mat structure, thereby forming a moisture barrier for the inner layers. This is especially advantageous when the inner layers are comprised of relatively hydrophilic fibers such as glass.

[00139] In one embodiment, the bonded nanofibers may improve the properties of existing polymer composites and films by providing nanofiber- reinforced polymer composites and films, and corresponding fabrication process, which have a reduced coefficient of thermal expansion, increased elastic modulus, improved dimensional stability, and reduced variability of properties due to either process variations or thermal history. Additionally, the increased stiffness of the material due to the nanofibers may be able to meet given stiffness or strength requirements.

[00140] The bonded nanofibers of the nano-porous non-woven 10 may be used in many known applications employing nanofibers including, but not limited to, filter applications, computer hard drive applications, biosensor applications and pharmaceutical applications. The nanofibers are useful in a variety of biological applications, including cell culture, tissue culture, and tissue

engineering applications. In one application, a nanofibrillar structure for cell culture and tissue engineering may be fabricated using the nanofibers of the present invention.

EXAMPLES

[00141 ] Various embodiments are shown by way of the Examples below, but the scope of the invention is not limited by the specific Examples provided herein. Example 1

[00142] The first polymer was Homopolymer Polypropylene (HPP), obtained in granule form from Lyondell Basell as Pro-fax 6301 and had a melt flow of 12 g/1 Omin (230^<Ό, ASTMD 1238). The granule HPP was pelletized using a twin screw extruder Prism TSE 16TC. The second polymer was Cyrtal Polystyrene (PS), obtained in pellet form from Total Petrochemicals as PS 500 and had a melt flow of 14g/1 Omin (200°C, ASTMD 1238). The PS and HPP pellets were premixed in a mixer at a weight ratio of 80/20. The mixture was fed into a co-rotating 1 6 mm twin-screw extruder, Prism TSE 16TC. The feed rate was 150 g min^"1 and the screw speed was 92 rpm. Barrel temperature profiles were 225, 255, 245, 240, and 235 °C. The blend was extruded through a rod die where the extrudate was subject to an extensional force that was sufficient to generate nanofibrillar structure. The extrudate was cooled in a water bath at the die exit and collected after passing through a pelletizer. The pellets were the first intermediate and contained parallel HPP nanofibers (approximately 80% of the fibers had a diameter less than 500nm and have an aspect ratio of greater than 40:1 ). When a section of the first intermediate was etched, the sample had no structural integrity indicating that a small percentage of the nanofibers were bonded to other nanofibers.

[00143] The first intermediate pellets were randomly arranged into a layer to form the pre-consolidation formation. The pre-consolidation formation was compression molded for 15 min using a carver hydraulic press forming the second intermediate, a solid nano-composite film with a thickness of 0.3 mm. The compression temperature was 320 °F and the compression pressure was 30 tons. This consolidation temperature was approximately the melting point of the PS. It was determined that approximately 90 % of the HPP fibers were bonded to other HPP nanofibers.

[00144] The second intermediate was immersed in toluene at room temperature for 30 minutes to remove PS from the blends as PS is soluble in toluene and PP is insoluble in toluene. This step was repeated for two more times to ensure complete removal of polystyrene. The etched film was then immersed in acetone and methanol for 30 minutes respectively, then air dried. The weight of the etched film was 20% of the original blend indicating that all or approximately all of the PS was removed.

[00145] The morphology of the etched nano-composite article was observed using a smayning electron microscope (SEM). The SEM images (Figure 31 A, 10OOx, Figure 31 B, 10OOOx) represent the top view of the etched films. The nanofibers are randomly connected and fused together, see Figures 31 A and 31 B.

Example 2

[00146] Example 2 was carried out with the same materials and process of Example 1 , except that the consolidation temperature was 340°F. This consolidation temperature was 20°F higher the melting point of HPP.

[00147] The morphology of the etched nano-composite article was observed using a SEM (Figures 32A - 1000x and Figure 32B - 10000x) represent the top view of the etched films. The nanofibers melted and fused into sheet like structure during consolidation and the nanofibers were destroyed. This consolidation temperature (at the given pressure and long resonance time) was proven to be too high to produce a nano-porous structure.

Example 3

[00148] Example 3 was carried out with the same materials and process of Example 1 , except that the consolidation temperature was 280°F. This consolidation temperature was 40 °F lower the melting point of HPP.

[00149] The morphology of the etched nano-composite article was observed using a SEM (Figure 33A - 1000x, Figure 33B - 10000x) represent the top view of the etched films. The nanofibers in the film were loosely connected and the film was very fragile to handle during testing indicating that less than 70% of the nanofibers were bonded to other nanofibers. This combination of consolidation temperature, pressure and resonance time was proven to be too low to produce nano-porous non-woven with good physical strength.

Example 4

[00150] Example 4 was carried out with the same materials and process of Example 1 , except that the consolidation temperature was 300°F. This consolidation temperature was 20°F lower the melting point of HPP.

[00151 ] The morphology of the etched nano-composite article was observed using an SEM (Figure 34A - 1 000x, Figure 34B - 5000x) represent the top view of the etched films. It may be seen that HPP nanofibers had started softening and bonding together at this temperature, but at least 70% of the nanofibers were not bonded together resulting in a structure that lacked integrity.

Example 5

[00152] Example 5 was carried out with the same materials and process of Example 1 , except that the consolidation temperature was 360°F. This consolidation temperature was 40°F higher than the melting point of HPP. The second intermediate disintegrated during etching. The nanofibers had ripened reverting back to discontinuous more circular regions from the nanofibers.

[00153] In Examples 1 -5, the only difference between the samples was the consolidation temperature (with the pressure and resonance time constant). The consolidation temperature is one processing condition that determines the degree of bonding between the nanofibers. The bonding of the nanofibers is reflected by the modulus of the second intermediate e.g. the nano-composite. Dynamic Mechanical Analysis (DMA) is one way of assessing the degree of consolidation without the need for etching away the second polymer. DMA was performed on the nano-composite films of Example 1 -5. The temperature sweep of the storage moduli was measured at 1 Hz and plotted in Figure 35.

[00154] When the discontinuous phase (first polymer) is in nanofiber form, the higher the degree of bonding between the fibers the higher the modulus the second intermediate will be. When the nanofibers ripen into droplets form, the modulus will decrease due to the breakdown of the nanofiber network. In Figure 35, the storage modulus (G') of the second intermediates increases as the consolidation temperature increases from 280 °F to 320 °F indicating the degree of bonding between nanofibers increases while maintaining their diameter and aspect ratio. However, G' decreases as the consolidation temperature increases from 320 °F to 360 °F indicating ripened minor phase structure that causes disintegration upon etching.

[00155] For the polymer system described in Examples 1 -5 (PS 500/PP 6301 ), 320 °F may be considered the highest consolidation temperature for a pressure of 30 tons and a resonance time of 15 minutes. This consolidation temperature window varies depending on the materials used, consolidation pressure, and resonance time.

Example 6

[00156] Example 6 was carried out with the same materials of Example 1 , except that the weight ratio of second polymer / first polymer (PS/HPP) was 75/25. The first intermediate pellets were cryoground into powder form. A layer of the powder was used as the pre-consolidation formation. The consolidation condition and etching procedure were the same as those described in Example 1 . From the SEM image shown in Figure 36 (which was imaged after dissolution of the second polymer), it may be seen that cryogrinding the first intermediate did not damage the nanofiber structure. The nanofiber morphology maintained during the process. 70% of the nanofibers had a diameter less than 400 nm and an aspect ratio higher than 50:1 . Example 7

[00157] Example 7 was carried out with the same materials of Example 6. The first intermediate pellets were melt extruded into thin films (10-50 urn thick) through extrusion within a Killion 32:1 KLB-100 Ti It- N -Whirl Model outfitted with a film extrusion die-head with a die temperature setting of 450° F., a melt temperature of about 425° F., and an extrusion screw rate of about 67 rpm, and collected on a roll package. At least 90% of the HPP nanofibers in the film were oriented along the machine direction (extrusion direction). When the first intermediate was etched in toluene, the film disintegrated. This indicated that only a small percentage of the nanofibers were bonded to other nanofibers so the resultant etched film had no structural integrity and contained mostly oriented individual nanofibers. The nano-composite film (not etched) was chopped into small pieces and cryoground into powder form. A layer of the powder was used as the pre-consolidation formation. The consolidation condition and etching procedure were the same as those described in Example 1 . The film did not disintegrate during etching indicating that a majority of the nanofibers were bonded to other nanofibers. From the SEM image shown in Fig. 37, it may be seen that by cryogrinding and consolidation the majority of the nanofibers were randomized and fused together.

Example 8

[00158] Example 8 was carried out with the same materials of Example 7. The first intermediate pellets were melt extruded into an 1 1 denier nano- composite fiber. The extensional force exerted on the melt created nano-fibrous HPP with an average aspect ratio of at least 1000:1 . At least 90% of the HPP nanofibers in the fibers were oriented along the machine direction (extrusion direction). The fibers were then chopped into small pieces and cryoground in to powder form. A layer of powder (pre-consolidation formation) was compression molded under the same conditions as Example 1 . The resulting second intermediate, the nano-composite film, was etched in the same way as Example 1 . A nano-porous non-woven was formed, see Fig. 38.

Example 9

[00159] Second polymer Total Crystal Polystyrene 535 (Total PS 535) (4 MFI,200C, ASTM D1 238) and and first polymer Homopolypropylene Profax PH350 purchased from Lyondellbasell(3.5 MFI at 230C, ASTMD1238) were mixed at weight ratio of 80/20 and melt extruded into pellets as described in

Example 1 . The first intermediate pellets were melt extruded into an 1 1 denier nano-composite fiber. The extensional force exerted on the melt created nanofibers of HPP with an average aspect ratio of at least 1000:1 . At least 90% of the HPP nanofibers in the fibers were oriented along the machine direction (extrusion direction). The fibers were then chopped into 2-6 inch long staple fibers and then carded and needle punched into a non-woven mat. This nonwoven mat was compression molded at the same condition as Example 1 . The resulting second intermediate was etched in the same way as Example 1 . A nano-porous non-woven was formed having at least 70% of the nanofibers bonded to other nanofibers. The SEM is shown in Fig. 39.

Example 10

[00160] The first intermediate pellets of Example 1 were cryoground into powder form. The powders were then soaked in acetone which is a good plasticizer for PS. The powders became sticky and were able to be manipulated into a doughnut shape by hand forming the pre-consolidation formation. The "doughnut" was taken out of the solvent and heated in an oven at 320 °F for 5 minutes resulting the second intermediate. The second intermediate was immersed in toluene at room temperature for 30 minutes to remove PS from the blends. PS is soluble and PP is not soluble in toluene. This step was repeated for two more times to ensure complete removal of polystyrene. The etched article was then immersed in acetone and methanol for 30 minutes respectively then air dried. A 3D nano-porous "doughnut" was formed, see Fig. 40A. The outer diameter of the structure is 7/8 inch. The micrograph is shown in Fig. 40B. It may be seen that the nanofiber morphology of the first intermediate was retained. The nanofibers were fused to one another (while still maintaining the nanofiber structural dimensions) upon consolidation.

Example 11

[00161 ] Example 1 1 was carried out with the same process of Example 1 with different materials. The second polymer was Total Crystal Polystyrene 535 (Total PS 535) (4 MFI,200°C, ASTM D1238) and the first polymer was EFEP RP 4020, a fluoropolymer purchased from Daiken with a melting temperature of 320°F (25-50 MFI at 265 °C ASTM D1238). The weight ratio of the second polymer to the first polymer was 80/20. The morphology of the etched nano- composite article was observed using a SEM (Figure 41 ). The nanofibers less than 800 nm in diameter were observed in the etched film. Sheet like structure were also observed. This is a result of the viscosity differences and the surface energy differences between the two polymers, the nanofibers a larger and wider distribution compared to Example 9.

Example 12

[00162] Example 12 was carried out with the same materials as in Example

9 and the first intermediate was prepared the same way as in Example 7. The first intermediate was extruded into 12.5um films. Two layers of film were cross lapped (meaning that the nanofiber axes of the two layers were perpendicular to each other) and consolidated at 280 °F at 30 tons for 15 minutes using a compression molder forming the second intermediate. The consolidated film was etched the same way as the other examples. Bonded nanofibers (greater than 70%) were observed in the etched nano-porous non-woven.

Example 13

[00163] Example 13 was carried out with the same materials Example 9 and the first intermediate was prepared the same way as Example 7. The first intermediate was extruded into 1 2.5um films. Two layers of film were stacked in parallel lapped (meaning that the nanofiber axes of the two layers were parallel to each other) and consolidated at 280 °F at 30 tons for 1 5 minutes using a compression molder forming the second intermediate. The consolidated film was etched the same way as the other examples. The film disintegrated during etching leaving parallel nanofibers behind.

Example 14

[00164] Crystal Polystyrene Total 535 (MFI 4g/1 Omin at 200C, ASTM D- 1238) and homopolymer polypropylene ExxonPP3155 (MFI 36g/10min at 230C, ASTM D-1238) were mixed at a weigh ratio of 80:20 and processed as the same method as sample 1 . The consolidation temperature was 300 °F at 1500 psi for 15 minutes. As seen in the SEM images of the etched film the fiber diameter distribution was wider compared to Examples 1 and 2 ranging from nano to micron sized, see Figure 42. This is a result of the viscosity differences between the two polymers.

Example 15

[00165] Example 15 was carried out with the same materials Example 9. The first intermediate was extruded into 12.5 μιη films. One film was calendared on (together with) a PP commercially available non-woven at 400°F, 1500 psi using a calendar roll forming the second intermediate. The nano-composite film softened and bonded on the PP non-woven fibers. The second intermediate was then etched using toluene resulting in a two layer composite construction (a nanofiber nano-porous layer and a non-woven layer). Multiple first intermediates would be able to be stacked on the PP non-woven layer if sufficient temperature or pressure is used. The nano-porous non-woven contained nanofibers, of which at least 70% of the nanofibers were bonded to other nanofibers.

Example 16

[00166] Example 16 was carried out with the same materials Example 9.

The first intermediate was extruded into 12.5 μιη films. One film was

compression molded on a PP non-woven at 280°F, 10 ton, and 15 minutes using a hydraulic compression molder forming the second intermediate. The nano- composite film softened and bonded on the PP non-woven fibers. The second intermediate was then etched using toluene resulting in a two layer composite construction (a nanofiber nano-porous layer and a non-woven layer). Multiple first intermediates would be able to be stacked on the PP non-woven layer if sufficient temperature or pressure is used. The nano-porous layer contained nanofibers, of which at least 70% of the nanofibers were bonded to other nanofibers.

Example 17

[00167] The nano-porous non-woven of Example 1 was used to filter industrial tap water. A majority of the rust particles were filtered. This nano- porous non-woven used as a membrane was measure to have an average pore size of 0.02 urn by capillary porometry. Example 18

[00168] Example 1 was also used to filter Staphylococcus aureus

(spherical with a diameter of 0.5-1 .5 micrometers) suspension. The cells were captured on the film surface. The nano-porous non-woven with the

Staphylococcus bacteria is shown in Figure 43.

Example 19

[00169] Example 1 was also used to filter human blood cells (typically 7-8 urn in diameter). The cells were captured on the film surface, see Figure 44. The SEM images showed Example 1 may be potentially used as a filtration membrane to filter bio cells.

Example 20

[00170] Example 1 was also used to filter rust from tap water (the rust particles were typically less than 1 micron in diameter). The rust particles were captured on the film surface, see Figure 45. The SEM images showed Example 1 may be potentially used as a filter for tap water.

Example 21

[00171 ] The matrix (second polymer) and particles used in Example 21 were high impact polystyrene (HIPS) which was obtained in pellet form from Total Petrochemicals as HIPS 935E and had a melt flow of 3.7g/10min (200 °C, ASTMD 1238). Elastomer-reinforced polymers are commonly referred to as impact modified or high impact polystyrene (HIPS). Typically, elastomer- reinforced styrene polymers having discrete elastomer particles and/or cross- linked elastomer dispersed throughout the styrene polymer matrix can be useful to improve the physical properties of the polymers. The HIPS contained polystyrene (PS) and particles which were believed to be elastomer particles and/or cross-linked elastomer having a wide distribution of in diameters from nanometer to microns. The particles made up approximately 35%wt of the HIPS.

[00172] The first polymer (nanofibers) used was homopolymer

polypropylene (HPP) which was obtained in granule form from Lyondell Basell as Pro-fax PH350 and had a melt flow of 3.5 g/10min (230°C, ASTMD 1238). The granule HPP was pelletized using a twin screw extruder Prism TSE 16TC. The HIPS and HPP pellets were premixed in a mixer at a weight ratio of 80/20. The mixture was fed into a co-rotating 16 mm twin-screw extruder, Prism TSE 16TC. The feed rate was 150 g min^"1 and the screw speed was 92 rpm. The blend was extruded through rod die where the extrudate was subject to an extensional force that sufficient enough to generate nanofibers in the matrix. The extrudate was cooled in a water bath at the die exit and collected after passing through a pelletizer. The pellets (the first intermediate) contained parallel HPP nanofibers (approximately 80% of the fibers had a diameter less than 500nm and had an aspect ratio of greater than 40:1 ).

[00173] The pellets (first intermediate) were randomly arranged into a layer to form the pre-consolidation formation. The pre-consolidation formation was compression molded for 15 minutes at a pressure of 30 tons and a temperature was 320 °F using a carver hydraulic forming the second intermediate, a solid nano-composite film with a thickness of 0.3 mm. It was determined that approximately 90 % of the HPP fibers were bonded to other HPP nanofibers.

[00174] The second intermediate was immersed in toluene at room temperature for 30 minutes to remove PS from the blends as PS is soluble in toluene and PP is insoluble in toluene. This step was repeated for two more times to ensure complete removal of polystyrene. The etched film was then immersed in acetone and methanol for 30 minutes respectively, then air dried. The weight of the etched film was 20% the weight of the initial blend.

[00175] The morphology of the nano-porous non-woven (etched nano- composite) was observed using a scanning electron microscope(SEM). The SEM images (Figure 46A, ^"Ι Ο,ΟΟΟχ and Figure 46B, 40,000x) represent the top view of the etched films. The nanofibers are randomly connected and fused together and the particles are inter-dispersed in the system with at least 50% adjacent and adhered to the nanofibers.

Example 22

[00176] Example 22 began with the nano-porous non-woven of Example 21 , then proceeded to functionalize the HIPS particles. The nano-porous non- woven was soaked in sulfuric acid to achieve sulfonation of the cross linked particles.

Example 23

[00177] The first polymer (nanofibers) used was homopolymer

polypropylene (HPP) which was obtained in granule form from Lyondell Basell as Pro-fax PH350 and had a melt flow of 3.5 g/1 Omin (230°C, ASTMD 1238). The nano-particles used were ALPHASAN^® available from Milliken & Company. ALPHASAN^® is an antimicrobial additive that utilizes silver to deter bacteria, fungus, mold, and other microbes from products. The second polymer (matrix) used was polystyrene (PS) Crystal PS 535 available from Total Chemical.

[00178] The HPP was pre-loaded with 10%wt ALPHASAN^® through melt blending using a twin screw extruder. The PS and HPP/Alpha San pellets were mixed at a weigh ratio of 80/20. The final composition of the blend was

PS/HPP/Alpha San 80/18/2. The mixture was processed to a nano-porous non- woven using the method set forth in Example 21 .

[00179] The morphology of the nano-porous non-woven (etched nano- composite) was observed using a scanning electron microscope (SEM). The SEM images Figure 47A (face view), Figure 47B (side view), and Figure 47C (side view) show that nanofibers were randomly connected and fused together and the nano-particles are inter-dispersed in the system with at least 50% adjacent and adhered to the nanofibers. The bright cubic particles shown in the SEM images are ALPHASAN^® crystals which in shape are cubes with ~500nm edges. Alpha San particles are dispersed trough out the nanofiber matrix. For comparison, in a regular PP injection molded plaque with 10% ALPHASAN^®, most of the Alpha San crystals are imbedded in the bulk which is not easily accessible, as shown in Figure 47D (face view). Only a few Alpha San crystals were exposed on the surface. Example 3 showed higher silver release rate than ALPHASAN^® incorporated a solid PP film due to the accessibility of the particle surface in the nano-porous non-woven.

Example 24

[00180] The matrix (second polymer) and nano-particles used in Example 24 were high impact polystyrene high impact Polymethyl Methacrylate (PMMA) Acrylic which was obtained in pellet form from EVonic Cro LLC as ACRYLITE PLUS® NTA-21 1 and had a melt flow of 3.8g/10 min ISO1 132. The PMMA- acrylic contained nano-particles which were believed to be cross-linked elastomer particles. The first polymer (nanofibers) used was homopolymer polypropylene (HPP) which was obtained in granule form from Lyondell Basell as Pro-fax HPP 6301 and had a melt flow of 12 g/10min (230^<Ό, ASTMD 1238). The weight ratio of PMMA-acrylic/PP in the blend was 75/25. The mixture was processed to a nano-porous non-woven using the method set forth in Example 21 .

[00181 ] After etching, the nano-porous non-woven contained spherical nano-particles with a diameter of approximately 250 nm uniformly dispersed and adhered onto the nanofibers, see SEM image Figure 48.

Example 25

[00182] The first polymer (nanofibers) used was homopolymer

polypropylene (HPP) which was obtained in granule form from Lyondell Basell as Pro-fax PH350 and had a melt flow of 3.5 g/10min (230°C, ASTMD 1238). The particles used were Ti0₂ with a mean particle diameter of less than 10 microns. The second polymer (matrix) used was polystyrene (PS) crystal PS 535 available from Total Chemical.

[00183] The HPP was pre-loaded with 2% wt Ti0₂ through melt blending using a twin screw extruder. The PS and HPP/Ti0₂ pellets were mixed at a weigh ratio of 80/20. The final composition of the first intermediate is

PS535/PH350/TiO₂ ALPHASAN^® 80/19.8/0.2. The mixture was processed to a nano-porous non-woven using the method set forth in Example 21 . The Ti0₂ was retained in the nanofiber matrix after etching indicating that the particles were adhered to the nanofibers.

Example 26

[00184] The first polymer (nanofibers) used was homopolymer

polypropylene (HPP) which was obtained in granule form from Lyondell Basell as Pro-fax PH350 and had a melt flow of 3.5 g/10min (230°C, ASTMD 1238). The particles used were Phoslite B631 C, a flame retardant particle, available from Italmatch Chemicals. The Phoslite has an average diameter of approximately 10 microns. The second polymer (matrix) used was polystyrene (PS) crystal PS 535 available from Total Chemical.

[00185] The HPP was pre-loaded with 3.3% wt Phoslite through melt blending using a twin screw extruder. The PS and HPP/ Phoslite pellets were mixed at a weight ratio of 80/20. The final composition of the first intermediate is PS535/PH350/ Phoslite 80/19.67/0.33. The mixture was processed to a nano- porous non-woven using the method set forth in Example 21 . The Phoslite was retained in the nanofiber matrix after etching indicating that the particles were adhered to the nanofibers. Example 27

[00186] The first polymer (nanofibers) was formed from homopolymer polypropylene (HPP) which was obtained in granule form from Lyondell Basell as Pro-fax HPP6301 and had a melt flow of 12 g/1 Omin (230°C, ASTM 1238). The second polymer (matrix) was formed from polystyrene (PS) crystal PS 500 available from Total Chemical, having a melt flow of 14g/10 min (200 °C, ASTM 1238).

[00187] The PS and HPP pellets were premixed in a mixer at a weight ratio of 80/20. The mixture was fed into a co-rotating 16 mm twin-screw extruder, Prism TSE 16TC. The feed rate was 150 g min^"1 and the screw speed was 92 rpm. The blend was extruded through rod die where the extrudate was subject to an extensional force that sufficient enough to generate nanofibers in the matrix. The extrudate was cooled in a water bath at the die exit and collected after passing through a pelletizer. The pellets (the first intermediate) contained parallel HPP nanofibers (approximately 80% of the fibers had a diameter less than 500nm and had an aspect ratio of greater than 40:1 ).

[00188] The first intermediate pellets were cryoground into powder form. The powders were mixed with an inorganic clay, palygorskite at a weight ratio of 99/1 . Palygorskite is also known as attapulgite, a magnesium aluminum phyllosilicate. The single particle of palygorskite is a ~4um needle in length with a diameter of 50 nm. The mixture of the cry ground intermediate and the clay powder was soaked in Acetone at room temperature for 10 minutes so that the mixture would become sticky and was more easily manipulated into a sheet (forming the pre-consolidation formation). Some degree of some compressing and stretching was applied to the "putty" to form the sheet.

[00189] The sheet was taken out of the solvent and heated in an oven at 320°F for 5 minutes to create the second intermediate. The second intermediate was immersed in toluene at room temperature for 30 minutes to remove PS from the blends. This step was repeated for two more times to ensure complete removal of polystyrene. The etched article was then immersed in acetone and methanol for 30mins respectively. A nanofiber and clay nano-porous non-woven was formed this way. The clay partices were left in the nanofiber matrix after etching indicating that the nano-particles were adhered to the nanofibers.

Example 28

[00190] Example 28 was a mono-extruded nano-composite and did not contain any supporting layers. The first polymer used to form the nanofibers was Homopolymer Polypropylene (HPP), obtained in granule form from Lyondell Basell as Pro-fax 6301 and had a melt flow of 12 g/10min (230 °C, ASTMD 1238). The granule HPP was pelletized using a twin screw extruder Prism TSE 16TC. The second polymer used to form the matrix was Cyrtal Polystyrene (PS), obtained in pellet form from Total Petrochemicals as PS 535 and had a melt flow of 14g/10min (200^<Ό, ASTMD 1238). The PS and HPP pellets were premixed in a mixer at a weight ratio of 80/20. The mixture was fed into a co- rotating 16 mm twin-screw extruder, Prism TSE 16TC. The feed rate was 150 g min^"1 and the screw speed was 92 rpm. Barrel temperature profiles were 225, 255, 245, 240, and 235 °C. The blend was extruded through a slit die to form a 25 micron film where the extrudate was subject to an extensional force that was sufficient to generate nanofibrillar structure. This film was the first intermediate.

[00191 ] The cross section of the cryofractured film (first intermediate) was examined via SEM in the direction normal to the machine direction. The PP fibers were normal to the field of view. The diameters of the PP fibers range from 100 nm to 500 nm. It can be in seen in Figures 49 and 50 that the PP fibers are finer and denser close to the surfaces of the film indicating higher shear rate near the edges. These fiber distribution characteristics are a result of the non-uniformity of the flow field across the film die during extrusion.

Example 29

[00192] The nano-composite of Example 28 was immersed in toluene at room temperature for 30 minutes to remove PS from the blends as PS is soluble in toluene and PP is insoluble in toluene. This step was repeated for two more times to ensure complete removal of polystyrene. The etched film was then immersed in acetone and methanol for 30 minutes respectively, then air dried. The sample had no structural integrity and fell apart.

Example 30

[00193] Example 30 was a co-extruded multi-layer nano-composite having a nano-composite layer surrounded on both sides by supporting layers. In the nano-composite layer, the first polymer used to form the nanofibers was Homopolymer Polypropylene (HPP), obtained in granule form from Lyondell Basell as Pro-fax 6301 and had a melt flow of 12 g/10min (230 °C, ASTMD 1238). The granule HPP was pelletized using a twin screw extruder Prism TSE 16TC. The second polymer used to form the matrix was Cyrtal Polystyrene (PS), obtained in pellet form from Total Petrochemicals as PS 535 and had a melt flow of 14g/10min (200 °C, ASTMD 1238). The PS and HPP pellets were premixed in a mixer at a weight ratio of 80/20. The mixture was fed into a co- rotating 16 mm twin-screw extruder, Prism TSE 16TC. The feed rate was 150 g min^"1 and the screw speed was 92 rpm. Barrel temperature profiles were 225, 255, 245, 240, and 235 °C. The blend was then co-extruded with two supporting layers each being formed from Crystal Polystyrene PS 535. The resultant three layer film, PS / (PS/PP) / PS with a thickness of 10 urn in each layer. The co- extruded film was the first intermediate.

[00194] The cross section of this film was examined via SEM. Again, the cross section is normal to the machine direction. In Figures 51 and 52, it can be seen that the gradient of the PP fiber size across the PS/PP 80/20 region was significantly decreased by using two PS layers on the sides of the nano- composite layer resulting in nanofibers that were substantially uniform from the outer edges of the nano-composite layer compared to the middle of the nano- composite layer. Example 31

[00195] The multi-layer nano-composite of Example 30 was calendared together with a nylon woven fabric to emboss the film with a fabric texture at 260°F at a calendar speed of 20ft/min. The resulting film was then immersed in toluene at room temperature for 30 minutes to remove PS from the nano- composite layer and the supporting layers as PS is soluble in toluene and PP is insoluble in toluene. This step was repeated for two more times to ensure complete removal of polystyrene. The etched film was then immersed in acetone and methanol for 30 minutes respectively, then air dried. A nano- porous non-woven was obtained. The fibers size and density were substantially uniform throughout the thickness of the nano-porous non-woven.

Example 32

[00196] Example 32 was made with the same materials and method as Example 30 except for that nano-composite layers were used with different concentrations of the first and second polymers. The first nano-composite layer had a PS/PP weight ratio of 80/20 and the second nano-composite layer had a PS/PP weight ratio of 90/10. The resultant structure was PS / (PS/PP 80/20) / (PS/PP 90/10) / PS, each layer being 10 microns thick. The size and density of the nanofibers were substantially uniform throughout the thickness of each nano- composite layer.

Example 33

[00197] The multi-layer nano-composite of Example 32 was calendared together with a nylon woven fabric to emboss the film with a fabric texture at

260°F at a calendar speed of 20 ft/min. The resulting film was then immersed in toluene at room temperature for 30 minutes to remove PS from the nano- composite layer and the supporting layers as PS is soluble in toluene and PP is insoluble in toluene. This step was repeated for two more times to ensure complete removal of polystyrene. The etched film was then immersed in acetone and methanol for 30 minutes respectively, then air dried. A nano- porous non-woven was obtained. The fibers size and density were substantially uniform throughout the thickness of the nano-porous non-woven. The size and density of the nanofibers and the density of the nano-particles were substantially uniform throughout the thickness of each nano-porous non-woven layer.

Example 34

[00198] Example 34 was made the same materials and method as

Example 30, except for that the PS used the PS/PP layer was high impact polystyrene (Total HIPS 935E), but the sacrificial PS layer remained the same as the crystal polystyrene, PS 535. HIPS 935E it is a high-impact polystyrene by Total that contains reinforcing particles as an impact modifier.

Example 35

[00199] The multi-layer nano-composite of Example 34 was calendared together with a nylon woven fabric to emboss the film with a fabric texture at 260°F at a calendar speed of 20 ft/min. The resulting film was then immersed in toluene at room temperature for 30 minutes to remove PS from the nano- composite layer and the supporting layers as PS is soluble in toluene and PP is insoluble in toluene. This step was repeated for two more times to ensure complete removal of polystyrene. The etched film was then immersed in acetone and methanol for 30 minutes respectively, then air dried. A nano- porous non-woven was obtained. The size and density of the nanofibers and the density of the nano-particles were substantially uniform throughout the thickness of the nano-porous non-woven. Example 36

[00200] Example 36 was a multi-layer nano-composite having five (5) layers total. The layers were, in order, a textile material, a nano-composite layer, a supporting layer, a nano-composite layer, and a textile material. The nano- composite layer and supporting layers were the same as described in Example 30 and was formed by co-extrusion. The textile material was a plain weave construction containing yarns of nylon 6. The supporting layers and the nano- composite layers had a thickness of 10 microns and the textile material had a thickness of 150 microns. The multi-layer nano-composite was heated to 320°F, with a pressure of 20 tons, for 15 minutes.

Example 37

[00201 ] The resulting composite of Example 36 was then immersed in toluene at room temperature for 30 minutes to remove PS from the nano- composite layers and the supporting layers as PS is soluble in toluene and PP is insoluble in toluene. This step was repeated for two more times to ensure complete removal of polystyrene. The etched composite was then immersed in acetone and methanol for 30 minutes respectively, then air dried. The resultant structures were two nano-porous non-wovens each partially embedded into the textile layer.

Example 38

[00202] The first polymer used to form the nanofibers was Homopolymer Polypropylene (HPP), obtained in granule form from Lyondell Basell as Pro-fax 6301 and had a melt flow of 12 g/1 Omin (230°C, ASTMD 1238). The granule HPP was pelletized using a twin screw extruder Prism TSE 16TC. The second polymer used to form the matrix was Cyrtal Polystyrene (PS), obtained in pellet form from Total Petrochemicals as PS 535 and had a melt flow of 14g/10min (200°C, ASTMD 1238). The PS and HPP pellets were premixed in a mixer at a weight ratio of 80/20. The mixture was fed into a co-rotating 16 mm twin-screw extruder, Prism TSE 16TC. The feed rate was 150 g min^"1 and the screw speed was 92 rpm. Barrel temperature profiles were 225, 255, 245, 240, and 235°C. The blend was extruded through a rod die where the extrudate was subject to an extensional force that was sufficient to generate nanofibrillar structure.

[00203] The extrudate was cooled in a water bath at the die exit and collected after passing through a pelletizer. The pellets were then re-melted and extrusion laminated onto a cotton fabric forming a 50 micron film on the poly/cotton fabric. The poly/cotton fabric was a plain weave having 80%wt cotton and 20%wt polyester. The fabric was preheated to 140 Ό right before the lamination step. The resultant nano-composite contained a matrix and at least 90% of the nanofibers were bonded to other nanofibers.

Example 39

[00204] Example 39 began with the nano-composite of example 38 and further consolidated it. The nano-composite was compression molded at 320 °F, 25 tons for 5 minutes. The matrix and nanofibers of the nano-composite completely penetrated through the entire thickness of the textile layer evidenced by a glossy film (matrix and nanofibers) that could be seen on the side of the textile opposite to the nano-composite layer.

Example 40

[00205] The first polymer used to form the nanofibers was Homopolymer Polypropylene (HPP), obtained in granule form from Lyondell Basell as Pro-fax 6301 and had a melt flow of 12 g/1 Omin (230°C, ASTMD 1238). The granule HPP was pelletized using a twin screw extruder Prism TSE 16TC. The second polymer used to form the matrix was Cyrtal Polystyrene (PS), obtained in pellet form from Total Petrochemicals as PS 535 and had a melt flow of 14g/10min (200°C, ASTMD 1238). The PS and HPP pellets were premixed in a mixer at a weight ratio of 80/20. The mixture was fed into a co-rotating 16 mm twin-screw extruder, Prism TSE 16TC. The feed rate was 150 g min^"1 and the screw speed was 92 rpm. Barrel temperature profiles were 225, 255, 245, 240, and 235 °C. The blend was extruded through a rod die where the extrudate was subject to an extensional force that was sufficient to generate nanofibrillar structure. The extrudate was cooled in a water bath at the die exit and collected after passing through a pelletizer. This film was the first intermediate and contained parallel HPP nanofibers (approximately 80% of the fibers had a diameter less than 500nm and have an aspect ratio of greater than 40:1 ).

[00206] The first intermediate pellets were extruded into a 50 micron thick film using film extrusion. This film was laid on one side of a piece of poly/cotton textile. The poly/cotton fabric was a plain weave having 80%wt cotton and 20%wt polyester, (describe). Two sacrificial layers of polystryrene (PS 500 from Cyrtal Polystyrene) were laid to surround the nano-composite and the textile layer forming a four layer structure: PS / Nano-composite / Textile Layer / PS. The four layer structure was consolidated at 320 °F, 25 tons of pressure for 15 minutes using a hydraulic carver press. One of the sacrificial layers migrated into the textile layer during consolidation preventing the nanofibers and matrix from the nano-composite from moving completely through the textile layer.

Example 41

[00207] Example 41 was produced with the same materials and method of Example 40 except for that no sacrificial layers was used in the consolidation step. The matrix and nanofibers of the nano-composite layer completely penetrated through the entire thickness of the textile layer evidenced by a glossy film (matrix and nanofibers) that could be seen on the side of the textile opposite to the nano-composite. Example 42

[00208] The resultant material from Example 40 was immersed in toluene at room temperature for 30 minutes to remove PS from the nano-composite as PS is soluble in toluene and PP is insoluble in toluene. This step was repeated for two more times to ensure complete removal of polystyrene. The etched composite (now nano-porous non-woven) was then immersed in acetone and methanol for 30 minutes respectively, then air dried.

Example 43

[00209] The resultant material from Example 41 was immersed in toluene at room temperature for 30 minutes to remove PS from the nano-composite as PS is soluble in toluene and PP is insoluble in toluene. This step was repeated for two more times to ensure complete removal of polystyrene. The etched composite (composite (now nano-porous non-woven) was then immersed in acetone and methanol for 30 minutes respectively, then air dried.

[00210] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0021 1 ] The use of the terms "a" and "an" and "the" and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms

"comprising," "having," "including," and "containing" are to be construed as open- ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein may be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[00212] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

WHAT IS CLAIMED IS:

1 . A nano-porous non-woven comprising:

a nano-porous non-woven layer having a first side and a second side, wherein the nano-porous non-woven layer comprises a plurality of nanofibers, wherein at least 70% of the nanofibers are bonded to other nanofibers; and, a textile layer selected from the group consisting of knit, woven, and non- woven layers having a textile layer thickness, wherein the textile layer is adjacent to the first side of the nano-porous non-woven layer, and wherein at least a portion of the nanofibers of the nano-porous non-woven layer are penetrated at least partially into the textile layer thickness.

2. The nano-porous non-woven of claim 1 , wherein the at least a portion of the nanofibers from the nano-porous non-woven layer penetrate the entire textile layer thickness.

3. A nano-porous non-woven comprising a plurality of nanofibers each having a surface and a center, wherein at least 70% of the nanofibers are bonded to other nanofibers, wherein the nanofibers comprise a bulk polymer and a third component, wherein the majority by weight at the surface of the nanofiber is the third component and the majority by weight at the center of the nanofiber is the bulk polymer, and wherein there is a concentration gradient of the third component from most concentrated to least from the surface of the nanofiber to the center of the nanofiber.

4. The nano-porous non-woven of claim 3, wherein the third component is selected from the group consisting of a lubricant, a polymer, and a molecule having reactive sites.

5. A nano-composite article comprising: a nano-composite and a supporting layer which are co-extruded, wherein the nano-composite has a first outer boundary adjacent the supporting layer, a second outer boundary on the side of the nano-composite opposite the supporting layer and an inner boundary located at the mid-point between the first outer boundary and the second outer boundary and parallel to the first outer boundary, wherein;

the nano-composite comprises a matrix and a plurality of nanofibers, wherein at least 70% of the nanofibers are bonded to other nanofibers; and, a supporting layer comprising a supporting polymer, wherein the supporting polymer is a thermoplastic polymer,

wherein the concentration of nanofibers are substantially uniform in the nano-composite from the inner boundary to the first boundary layer.

6. The nano-composite article of claim 5, further comprising a third layer comprising the supporting polymer, wherein the third layer is adjacent the second outer boundary layer and wherein the concentration of nanofibers in the nano-composite are substantially uniform from the first outer boundary layer to the second outer boundary layer.

7. The nano-composite of claim 5, wherein the matrix of the nano-composite and the thermoplastic of the supporting layer are soluble in the same solvent.

8. A nano-porous non-woven comprising a plurality of thermoplastic nanofibers and a plurality of particles, wherein at least 50% of the particles are positioned adjacent a surface of the nanofibers and at least 70% of the nanofibers are fused to other nanofibers within the nano-porous non-woven.

9. The nano-porous non-woven of claim 8, wherein the particles comprise material selected from the group consisting of inorganic material, organic material, core/shell particles, functionizable particles and particles having antimicrobial properties.

10. A nano-porous non-woven comprising a plurality of core/shell nanofibers, wherein at least 70% of the nanofibers are bonded to other nanofibers, wherein the core of the core/shell nanofibers comprises a core polymer and the shell of the core/shell nanofibers comprises a shell polymer, wherein at least a portion of the core polymer interpenetrates the shell of the nanofiber and at least a portion of the shell polymer interpenetrates the core of the nanofiber.

1 1 . The nano-porous non-woven of claim 10, wherein the shell polymer is located between the bonds of the core/shell nanofibers.

12. The process of forming a nano-composite comprising, in order:

a) mixing a first thermoplastic polymer and a second thermoplastic polymer in a molten state forming a molten polymer blend, wherein the second polymer is soluble in a first solvent, wherein the first polymer is insoluble in the first solvent, and wherein the first polymer forms discontinuous regions in the second polymer, and optionally cooling the polymer blend to a temperature below the softening temperature of the first polymer;

b) subjecting the polymer blend to extensional flow, shear stress, and heat such that the first polymer forms nanofibers having an aspect ratio of at least 5:1 , and wherein less than about 30% by volume of the nanofibers are bonded to other nanofibers, wherein the nanofibers are generally aligned along an axis;

c) cooling the polymer blend with nanofibers to a temperature below the softening temperature of the first polymer to preserve the nanofiber shape forming a first intermediate;

d) forming the first intermediate into a pre-consolidation formation;

e) consolidating the pre-consolidation formation at a consolidation temperature forming a second intermediate, wherein the consolidation temperature is above the T_g and of both the first polymer and second polymer, wherein consolidating the pre-consolidation formation causes nanofiber movement, randomization, and at least 70% by volume of the nanofibers to fuse to other nanofibers.

13. The process of claim 12, wherein subjecting the molten polymer blend to extensional flow and shear stress comprises extruding the molten polymer blend into fibers and wherein forming the pre-consolidated formation comprises forming the fibers into a layer selected from the group consisting of a knit layer, a woven layer, and a non-woven layer and stacking the at least layer.

14. The process of claim 12, wherein subjecting the molten polymer blend to extensional flow and shear stress comprises extruding the molten polymer blend into a film and wherein forming the pre-consolidated formation comprises stacking at least one of the films.

15. The process of claim 12, further comprising:

f) applying the first solvent to the second intermediate dissolving away at least a portion of the second polymer.

16. The process of claim 12, wherein step d) comprises forming the first intermediate into a pre-consolidation formation comprises layering the cooled polymer blend with a textile layer, wherein the textile layer is selected from the group consisting of knit, woven, and non-woven layers.

17. The process of claim 12, wherein step b) comprises subjecting the polymer blend to extensional flow, shear stress, and heat comprises extruding the polymer blend onto a textile layer.

18. The process of claim 12, wherein step comprises mixing a first thermoplastic polymer, a second thermoplastic polymer, and a third component in a molten state forming a molten polymer blend, wherein the third component is more miscible with the first thermoplastic polymer than the second thermoplastic polymer.

19. The process of claim 18, wherein the third component is selected from the group consisting of a lubricant, a polymer, and a molecule having reactive sites.

20. The process of claim 12, wherein step a) comprises mixing a first

thermoplastic polymer and a second thermoplastic polymer in a molten state forming a molten polymer blend and co-extruding the blend with a supporting layer.

21 . The process of claim 12, wherein step a) comprises mixing a plurality of particles, a first thermoplastic polymer and a second thermoplastic polymer, wherein the first and second polymer are in a molten state.

22. The process of claim 21 , wherein the particles comprise material selected from the group consisting of inorganic material, organic material, core/shell particles, functionizable particles and particles having antimicrobial properties.

23. The process of forming a nano-porous non-woven comprising, in order: a) mixing a core thermoplastic polymer, a shell thermoplastic polymer and a matrix thermoplastic polymer in a molten state forming a molten polymer blend, wherein the matrix polymer is soluble in a first solvent, wherein the core and shell polymers are insoluble in the first solvent, wherein the core polymer is not miscible with the shell polymer, wherein the core polymer forms discontinuous regions in the matrix polymer, wherein the shell polymer forms a shell around the discontinuous regions between the core polymer and the matrix polymer and optionally cooling the polymer blend to a temperature below the softening temperature of the core and shell polymers;

b) subjecting the polymer blend to extensional flow, shear stress, and heat such that the core and shell polymers forms core/shell nanofibers having an aspect ratio of at least 5:1 , and wherein less than about 30% by volume of the nanofibers are bonded to other nanofibers, wherein the nanofibers are generally aligned along an axis, wherein at least a portion of the core polymer

interpenetrates the shell of the nanofiber and at least a portion of the shell polymer interpenetrates the core of the nanofiber;

c) cooling the polymer blend with nanofibers to a temperature below the softening temperature of the core and shell polymers to preserve the nanofiber shape forming a first intermediate;

d) forming the first intermediate into a pre-consolidation formation;

e) consolidating the pre-consolidation formation at a consolidation temperature forming a second intermediate, wherein the consolidation temperature is above the T_g and of core, shell, and matrix polymers, wherein consolidating the pre-consolidation formation causes core/shell nanofiber movement, randomization, and at least 70% by volume of the core/shell nanofibers to fuse to other core/shell nanofibers; and,

f) applying the first solvent to the second intermediate removing at least a portion of the matrix polymer.