Gas permeable membranes including 3D graphene carbons
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-06
- Publication Date
- 2026-08-13
Smart Images
Figure US2026014202_13082026_PF_FP_ABST
Abstract
Description
GAS PERMEABLE MEMBRANES INCLUDING 3D GRAPHENE CARBONSRELATED APPLICATION
[0001] This Patent Application claims priority to U.S. Provisional Patent Application No.63 / 754,856 entitled “GAS PERMEABLE MEMBRANES INCLUDING 3D GRAPHENE CARBONS” and filed on February 06, 2025, which is assigned to the assignee hereof. The disclosure of the prior Application is considered part of and is incorporated by reference in this Patent Application in its entirety.TECHNICAL FIELD
[0002] This disclosure relates generally to permeable membranes, and more particularly, to permeable membranes that include three-dimensional graphene.DESCRIPTION OF RELATED ART
[0003] Recent developments in water resistant vapor permeable membranes (“WRVP”) are focused on improving the durability water vapor permeable membranes. However, further improvements in vapor permeable membranes are desired.SUMMARY
[0004] This Summary is provided to introduce in a simplified form a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.
[0005] In some implementations, a gas permeable membrane may include a non-woven fabric. In some instances, a non-woven fabric may include a web of polymer fibers and a carbon-based material including a plurality of three-dimensional graphene fragments (“3DG carbon fragments”) disposed in the web of polymer fibers. In some other instances, the 3DG carbon fragments may be disposed in at least some of the polymer fibers. In some examples, at least some of the 3DG carbon fragments may be oriented at a non-zero surface angle relative to an external surface of a respective polymer fiber.
[0006] In some implementations, the 3DG carbon fragments may each include a first end anchored within a corresponding polymer fiber, and an opposing second end disposed at a distance from an external surface of the corresponding polymer fiber. In some otherimplementations, the 3DG carbon fragments may be disposed as 3DG carbon layers and each 3DG carbon layer may include a first side anchored within a corresponding polymer fiber, and an opposing exposed second side disposed at a distance from an external surface of the corresponding polymer fiber.
[0007] In some implementations, the web of polymer fibers including the carbon-based material may be based on a flash spinning process. In some other implementations, at least some of the 3DG carbon fragments may be oriented at a non-zero surface angle relative to an external surface of a respective polymer fiber by applying a charge to the polymer solution associated with the flash spinning process. In some other implementations, the 3DG carbon fragments may be disposed as 3DG carbon layers and may each include a first side anchored within a corresponding polymer fiber, and an opposing exposed second side disposed at a distance from an external surface of the corresponding polymer fiber.
[0008] In some implementations, the gas permeable membrane may be configured to be selectively permeable to water vapor. In some examples, a gas permeable membrane may be configured to be selectively permeable to a gas associated with one or more of a mixture of gases, or a gas-liquid mixture. An example of a mixture of gases may include oxygen, carbon dioxide, carbon monoxide, nitrogen, methane, or water vapor.
[0009] In some implementations, the polymer fibers may include thermoplastic polymer fibers. In some examples, the thermoplastic polymer fibers may include fibers made of one or more of polyethylene, high density polyethylene (“HDPE”), polypropylene, Nylon, polyester, polyurethane, or polyvinylidene fluoride. Nylon may include a group of polyamides including one or more of Nylon 66, Nylon 6, Nylon 12, or Nylon 46, among other similar non- limiting examples.
[0010] In some implementations, the 3DG carbon fragments may further include amorphous graphitic carbon particles. In some instances, 3DG carbon fragments may include one or more allotropes of carbon including graphene. In some other instances, the allotropes of carbon including graphene may include one or more carbon nanotubes (“CNT”), carbon nano onions (“CNOs”), carbon nanofibers, or fullerenes.
[0011] In some implementations, 3DG carbon fragments may include flaky graphene including one or more interconnected bundles of electrically conductive graphene layers. In some instances, the graphene layers may be arranged as one or more stacks connected to each other to define a 3D porous scaffold structure including mesopores. In some other instances, the one or more stacks may be disposed substantially orthogonal to each other. In someexamples, the graphene layers may be characterized by a linear dimension of between approximately 50 nm and 200 nm. In some other examples, the graphene layers may include one or more of single layer graphene (“SLG”), few layer graphene (“FLG”), or many layer graphene (“MLG”).
[0012] In some implementations, the 3DG carbon fragments may be characterized by a Raman spectroscopy signature having an ID / IG ratio of less than 1. In some other implementations, the 3DG carbon fragments may be characterized by a Brunauer-Emmett-Teller (“BET”) surface area between approximately 50 m2 / g and 500 m2 / g measured using nitrogen gas. In some instances, the 3DG carbon fragments may be characterized by a graphene to amorphous graphitic carbon ratio between approximately 1% and 95%. In some other instances, the 3DG carbon fragments are characterized by an electrical conductivity of between approximately 500 S / m and 20,000 S / m when compressed at pressure of approximately 12,000 pounds per square inch (psi).
[0013] In some implementations, 3DG carbon fragments may further include one or more of oxygen containing surface functional groups, nano-silica particles, or nano-silica surface functional groups. In some other implementations, the oxygen containing surface functional groups may include one or more of epoxide (C-O-C), hydroxyl (-OH), ether (C-O-C), ketone (O-C=O), or carboxylic acid (-COOH) groups.
[0014] In some implementations, the gas permeable membrane may include a non-woven fabric. In some instances, a non-woven fabric may include a web of polymer fibers and a carbon-based material including a plurality of three-dimensional graphene fragments (“3DG carbon fragments”). In some other instances, at least some of the 3DG carbon fragments may be embedded within at least some of the polymer fibers. In some examples, the carbon-based material may further include amorphous graphitic carbon particles. In some instances, the web of polymer fibers may be based on a flash spinning process. In some other the web of polymer fibers may include thermoplastic polymer fibers.
[0015] In some implementations, a gas permeable membrane may include a non-woven fabric. In some examples, the non-woven fabric may include a web of polymer fibers and a carbon-based material including a plurality of three-dimensional graphene fragments (“3DG carbon fragments”). At least some of the 3DG carbon fragments may each form a bridge connecting adjacent polymer fibers. In some instances, the carbon-based material may further include amorphous graphitic carbon particles. In some other instances, the polymer fibers may include thermoplastic polymer fibers.
[0016] In some implementations, a composite gas permeable membrane may include one or more carbon-based layers including a plurality of three-dimensional graphene fragments (“3DG carbon fragments”), and a plurality of polymer membranes. In some instances, the one or more carbon-based layers may be sandwiched between two adjacent polymer membranes and fused to the polymer membranes based on, or using, one or more of Joule heating or hot pressing. In some other instances, the plurality of polymer membranes may include thermoplastic polymers. In some other instances, the thermoplastic polymers may include one or more of polyethylene, high density polyethylene (“HOPE”), polypropylene, nylon, polyester, polyurethane, or polyvinylidene fluoride. In some implementations, the 3DG carbon fragments may include one or more allotropes of carbon including graphene. In some instances, the allotropes of carbon may include one or more carbon nanotubes (“CNT”), carbon nano onions (“CNOs”), carbon nanofibers, or fullerenes.
[0017] In some implementations, a composite gas permeable membrane may include one or more carbon-based layers including a plurality of three-dimensional graphene fragments (“3DG carbon fragments”), and one or more polymer membranes. In some instances, the one or more carbon-based layers may be disposed on a surface associated with the one or more polymer membranes and fused to the one or more polymer membranes using one or more of Joule heating or hot pressing. In some instances, the 3DG carbon fragments may include one or more allotropes of carbon including graphene. In some other instances, the allotropes of carbon may include one or more carbon nanotubes (“CNT”), carbon nano onions (“CNOs”), carbon nanofibers, or fullerenes. In some examples, the one or more polymer membranes include thermoplastic polymers. In some other examples, the thermoplastic polymers may include one or more of polyethylene, high density polyethylene (“HDPE”), polypropylene, nylon, polyester, polyurethane, or polyvinylidene fluoride.
[0018] Details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims. Note that the relative dimensions of the following figures may not be drawn to scale.BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figures 1A–1B show schematic diagrams of a gas permeable membrane including graphene, according to some implementations.
[0020] Figure 2 shows a schematic diagram of a mesoporous nanoparticle in 3-dimensional graphene (3DG carbon fragments), according to some implementations.
[0021] Figure 3A shows another diagram of 3DG carbon fragments, according to some implementations.
[0022] Figure 3B shows a transmission electron microscope (TEM) micrograph of 3DG carbon fragments, according to some implementations.
[0023] Figure 3C shows a scanning electron microscope (SEM) micrograph of 3DG carbon fragments, according to some implementations.
[0024] Figure 4A shows a schematic diagram of a primary carbon particle in 3DG carbon fragments, according to some implementations.
[0025] Figure 4B shows a TEM image of primary particles and agglomerates in 3DG carbon fragments, according to some implementations.
[0026] Figure 4C shows a TEM image of 3DG carbon agglomerates, according to some implementations.
[0027] Figure 5 shows a schematic diagram of another primary carbon particle in 3DG carbon fragments, according to some implementations.
[0028] Figure 6 shows a scanning transmission electron microscopy (STEM) micrograph of 3DG carbon fragments, according to some implementations.
[0029] Figure 7 shows a schematic diagram of a composite gas permeable membrane, according to some implementations.
[0030] Figure 8 shows a schematic diagram of another composite gas permeable membrane, according to some implementations.
[0031] Figure 9 shows a schematic diagram of a composite gas permeable membrane, according to some implementations.
[0032] Like reference numbers and designations in the various drawings indicate like elements.DETAILED DESCRIPTION
[0033] The following description is directed to some example implementations for the purpose of describing the innovative aspects of this disclosure. However, a person of ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. The implementations described herein may be implemented in a variety of applications and may be tailored to compensate for various performance related deficiencies. As such, the disclosed implementations are not to be limited by the examples provided herein, but rather encompass all implementations contemplated by the attached claims. Additionally, well-known elements of the disclosure will not be described in detail or will be omitted so as not to obscure the relevant details of the disclosure.
[0034] As referred to herein in this disclosure, a gas includes water vapor. A hydrophobic material is characterized by a contact angle associated with a water droplet of greater than 90°. Additionally, “3DG carbon fragments” may also be referred to herein as “3DG carbons,” or “3DG carbon flakes.” In this disclosure, “graphene” refers to an allotrope of carbon in the form of a two-dimensional, atomic-scale, hexagonal lattice in which one atom forms each vertex. The carbon atoms in graphene may be sp2hybridized carbon atoms. Additionally, graphene has a Raman spectrum with two main peaks: a G-mode at approximately 1580 cm-1and a D mode at approximately 1350 cm-1(when using a 532 nm excitation laser).
[0035] Various aspects of the novel compositions and methods are described more fully herein with reference to the accompanying drawings. These aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Although some examples and aspects are described herein, many variations and permutations of these examples fall within the scope of the disclosure.Although some benefits and advantages of the various aspects are mentioned, the scope of the disclosure is not intended to be limited to benefits, uses, or objectives. The detailed description and drawings are merely illustrative of the disclosure rather than limiting, the scope of the disclosure being defined by the appended claims and equivalents thereof.
[0036] Water resistant vapor permeable WRVP membranes are used in outdoor apparel, protective clothing, and construction and building materials. These applications require robust membranes to provide a barrier to moisture or other liquids, while selectively enabling vapor permeability.
[0037] Selectivity to water vapor permeability may be tuned by modifying the microporosity associated with WRVP porous membranes. As vapor molecules are relatively smaller in size than liquid droplets, tuning microporosity by engineering the average size and distribution of pores may allow vapor molecules to pass through the membranes, while blocking the transport of liquid droplets. In applications where airflow and moisture management are required, air and water vapor may flow through the membranes, which are sometimes referred to as “breathable” membranes. Tyvek® (supplied by DuPont de Nemours, Inc.) is an example of a microporous breathable membrane.
[0038] In some instances, a hydrophobic material may be coated on the surface of the porous membranes to encourage water or other liquids to form beads on the surface without penetrating the membranes. In some examples, a WRVP membrane may include a hydrophobic coating material, for example, Teflon® (also referred to herein as “PTFE”) which repels liquid water droplets. Gore-Tex® (supplied by W. L. Gore & Associates) is an example of a PTFE membrane. In some other instances, WRVP membranes may incorporate both tuning of porosity and hydrophobic surface treatment to provide desired waterproofing without compromising breathability.
[0039] In some examples, WRVP membranes may be used in protective clothing including outdoor wear or athletic wear, which allow sweat to escape while preventing the ingress of rain or external moisture. In some other examples, WRVP membranes may be used in building materials to protect structures from rainwater ingress while allowing trapped moisture to evaporate, thereby preventing undesirable mold formation. In some examples, WRVP membranes may be used in packaging products, for example, packaging for food or medical supplies. WRVP membranes prevent moisture buildup within a package and protects the contents with a package from ambient water. For example, Tyvek® AirGuard® Smart (supplied by DuPont de Nemours, Inc.) may be used to prevent damage to structures and manage thermal efficiency by adapting to various moisture conditions. Additional applications of WRVP membranes include aerospace components, automotive interiors, health care and hygiene products, greenhouse linings, battery packaging, solar panels, enclosures for electronics, luggage, footwear, sports equipment, among other similar nonlimiting examples of products, components, and applications.
[0040] Currently, WRVP membranes are susceptible to wear, or may be fouled or damaged. As such, these membranes are characterized by poor durability. Accordingly,durable, gas permeable, and liquid impermeable membranes that permit tuning of hydrophobicity and lightweighting are desired.
[0041] The gas permeable membranes and / or composite gas permeable membranes including 3DG carbon fragments described herein may be characterized by one or more advantages compared to currently available WRVP membranes. In some instances, the gas permeable membranes including 3DG carbon fragments may provide for greater flexibility in the pore size distribution, allowing for precise tuning of pore structures that may result in better vapor permeability and moisture barrier properties. In some other instances, the gas permeable membranes including 3DG carbon fragments may be characterized by improved tensile strength and resistance to tears compared to gas permeable membranes that do not include 3DG carbon fragments. As such, the gas permeable membranes including 3DG carbon fragments described herein may be used in thin walling applications. “Thin walling” may refer to methods for producing thin walls, including lightweight plastic components, or building envelopes where less concrete is used compared to conventional wall panels. In some examples, the gas permeable membranes including 3DG carbon fragments may be characterized by improved electrical conductivity compared to the bare thermoplastic polymers. Additionally, the gas permeable membranes including 3DG carbon fragments described herein may be characterized by improved durability or abrasion resistance compared to polymeric membranes including a surface coating of graphene or graphene oxide.
[0042] Figures 1A–1B show schematic diagrams 100A–100B of a gas permeable membrane including graphene, according to some implementations. In some implementations, a gas permeable membrane may include a non-woven fabric. In some instances, a gas permeable membrane may include a web 101 of polymer fibers 102 and a carbon-based material including a plurality of three-dimensional graphene fragments (“3DG carbon fragments”) disposed in the web of polymer fibers. In some other instances, the 3DG carbon fragments may be disposed in at least some of the polymer fibers. In some examples, at least some of the 3DG carbon fragments 103 may be oriented at a non-zero surface angle (“D”) relative to an external surface 106 of a respective polymer fiber 102. Referring to Figure IB, in some implementations, each of the 3DG carbon fragments 103 may include a first end 104 anchored within a polymer fiber 102, and an opposing second end 105 disposed at a distance from the external surface 106 of a polymer fiber. Accordingly, in some implementations, 3DG carbon fragments 103 may extend out, or protrude out, from theexternal surface 106 of the polymer fibers. In some other implementations, the 3DG carbon fragments may be disposed as 3DG carbon layers and may include a first side anchored within the polymer fibers, and an opposing exposed second side disposed at a distance from an external surface of the polymer fibers.
[0043] Without being bound by any particular theory, 3DG carbon fragments 103 that extend out, or protrude out, from external surface 106 of the polymer fibers may modify one or more of surface chemistry or surface roughness of the polymer fibers or increase the hydrophobicity of the polymer fibers. Accordingly, water droplets may form beads and “roll off’ the surface of the gas permeable membranes including 3DG carbon fragments.
[0044] In some implementations, the web 101 of polymer fibers 102 including the carbon-based material may be based on a flash spinning process. In some other implementations, at least some of the 3DG carbon fragments 103 may be oriented at a nonzero surface angle (“9”) relative to an external surface 106 of a respective polymer fiber 102 by applying a charge to the polymer solution associated with the flash spinning process. In some implementations, a gas permeable membrane may be configured to be selectively permeable to water vapor. In some examples, a gas permeable membrane may be configured to be selectively permeable to a gas associated with one or more of a mixture of gases, or a gas-liquid mixture.
[0045] In some implementations, the polymer fibers 102 may include thermoplastic polymer fibers. In some examples, thermoplastic polymer fibers may include fibers made of one or more of polyethylene, high density polyethylene (“HDPE”), polypropylene, nylon, polyester, polyurethane, or polyvinylidene fluoride. Nylon includes polyamide thermoplastic polymers. Nylon may include a group of polyamides including one or more of Nylon 66, Nylon 6, Nylon 12, or Nylon 46, among other similar non-limiting examples.
[0046] Returning to Figures 1A, in some other implementations, a gas permeable membrane may include a web 101 of polymer fibers 102 and a carbon-based material including a plurality of three-dimensional graphene fragments (“3DG carbon fragments”) 107. In some other instances, at least some of the 3DG carbon fragments 107 may be embedded within at least some of the polymer fibers 102. In some examples, the carbonbased material may further include amorphous graphitic carbon particles. In some instances, the web 101 of polymer fibers 102 including the carbon-based material may be based on a flash spinning process. In some other implementations, the web of polymer fibers may include thermoplastic polymer fibers.
[0047] In some other implementations, a gas permeable membrane may include a web 101 of polymer fibers 102, and a carbon-based material including a plurality of three-dimensional graphene fragments (“3DG carbon fragments”). Referring to Figure 1 A, at least some of the 3DG carbon fragments 108 may each form a bridge connecting adjacent polymer fibers. In some instances, the carbon-based material may further include amorphous graphitic carbon particles. In some other instances, the polymer fibers may include thermoplastic polymer fibers. In some instances, enhancing one or more mechanical properties associated with the gas permeable membranes using the 3DG carbon fragments described herein may permit the use of thin and durable membranes to improve gas or water vapor permeability rates without incurring a penalty on lightweighting.
[0048] Accordingly, gas permeable membranes including 3DG carbon fragments may provide for tuning and / or improving the hydrophobicity of the membranes and mechanical properties of the membranes. Tuning of mechanical properties may include one or more of tuning the average pores size, pore size distribution, overall porosity, improving tear strength, or dimensional stability associated with gas permeable membranes. In some instances, 3DG carbon fragments may provide an irregular nanostructure on the surfaces of gas permeable membranes, which may increase hydrophobicity associated with the gas permeable membranes. As previously described herein, 3DG carbon fragments may significantly increase the mechanical strength of the polymer matrix associated with the gas permeable membranes. This enhanced structural integrity may enable the formation of finer pores within the membrane, for example, pores that are small enough to block water diffusion, provide for gas separation, while maintaining the shape of the membranes. Improving tear strength may extend the lifespan of the gas permeable membranes and permit thinner and lighter membranes to be used without compromising mechanical integrity associated with gas permeable membranes. As a result, thin membranes may be designed with improved moisture management, which can lead to better vapor permeability without sacrificing water resistance. Improved dimensional stability prevents deformation or shrinkage, ensuring the integrity of the pore structure in a gas permeable membrane is preserved over time. In some examples, the gas permeable membranes including 3DG carbon fragments described herein may be characterized by a thickness of between about 50 pm and about 150 pm.
[0049] The 3DG carbon fragments 103, 107, or 108 as described above with reference to Figure 1 A, may further include amorphous graphitic carbon particles. In some instances, 3DG carbon fragments 103, 107, or 108 may include one or more allotropes of carbonincluding graphene. In some other instances, the allotropes of carbon including graphene may include one or more carbon nanotubes (“CNT”), carbon nano onions (“CNOs”), carbon nanofibers, or fullerenes.
[0050] Figure 2 shows a schematic diagram of a mesoporous carbon nanoparticle 200 in 3DG carbon fragments, according to some implementations. In this disclosure, 3DG carbon fragments may include agglomerates of mesoporous nanoparticles 200. The 3DG carbon fragments including agglomerates of nanoparticle 200 (as described below) may be produced by high throughput, low-cost, cracking of a hydrocarbon gas (including natural gas) in an atmospheric microwave plasma reactor. An example of a microwave plasma reactor that can be used to produce the 3DG carbon fragments is disclosed in commonly owned U. S. Pat. No.9,767,992, which is incorporated by reference herein in its entirety. For example, 3DG carbon fragments may be formed in-flight and grown by adding additional carbon-based materials derived from incoming carbon-containing gas within a microwave-plasma reaction chamber.
[0051] A plurality of primary carbon nanoparticles 200 produced by one or more methods including thermal cracking of a hydrocarbon gas or source material may be coalesced or joined to form agglomerates of primary particles. An aggregate may be considered to be a discrete, colloidal entity that is the smallest dispersible unit composed of coalesced primary carbon nanoparticles. A primary carbon particle may be considered to be a spheroidal shaped, non-discrcct component of an aggregate that is separable from the aggregate only by fracturing. The primary carbon particles may be connected together by one or more of Van der Waals forces, covalent bonds, ionic bonds, metallic bonds, or by other physical or chemical interactions. Additionally, a plurality of aggregates may be considered to be agglomerates. Since aggregates of at least 1 pm in size may be considered to be agglomerates, the term “aggregates” also includes “agglomerates” in this disclosure. The term “fragments” includes “agglomerates” in this disclosure. A carbon nanoparticles aggregate may be characterized by a principal dimension (diameter, length, width) of greater than about 1 pm.
[0052] In some implementations, carbon nanoparticles 200 may be or may include three-dimensional (“3D”) multi-modal mesoporous carbon nanoparticles. A mesoporous material, as generally understood and as referred to herein, includes a material containing pores with diameters between 2 nm and 50 nm, according to IUPAC nomenclature. For the purposes of comparison, IUPAC defines microporous material as a material having pores smaller than 2nm in diameter and defines macroporous material as a material having pores larger than 50 nm in diameter. In some instances, mesoporous carbon particle 200 may be characterized by a three-dimensional (“3D”) hierarchical porous structure including pores 210. In some aspects, at least a portion of the hierarchical porous structure may further define a 3D open porous scaffold structure 220.
[0053] Nanoparticle 200, and the 3DG carbon fragments described herein, may include one or more interconnected bundles 230 of electrically conductive graphene layers or flakes. Accordingly, in some instances, the 3DG carbon fragments may include “flaky graphene.” The flaky graphene may include the one or more interconnected bundles of electrically conductive graphene layers. Each interconnected bundle 230 may include one or more stacks 232 of graphene layers. Each stack 232 may include a plurality of graphene layers 236 that are generally stacked horizontally as more clearly shown in stack 240. One or more stacks 232 of graphene layers 236 may be arranged to form a 3D porous scaffold structure 220. That is, a plurality of stacks 232 of electrically conductive graphene layers 236 may be sintered together to define the 3D open porous scaffold structure 220 (which includes mesopores 210 in the example of Figure 2). In some implementations, one or more of the stacks 232 may be connected substantially orthogonal to each other. The open porous scaffold structure 220 may be configured to provide electrical conduction between contact points (not shown for simplicity) of the stacks of graphene layers 236. In some implementations, each graphene layer 236 may be characterized by a diameter or linear dimension (“La”) of between about 50 nm to about 200 nm. The graphene stack 232 may include few layer graphene (“FLG”), which may be composed of 5 to 15 layers of graphene. A plurality of primary carbon nanoparticles 200 may be coalesced or joined to form agglomerates of primary particles.
[0054] In some implementations, the 3DG carbon fragments described herein may be characterized by a Brunauer-Emmett-Teller (“BET”) surface area measured using nitrogen gas of about 50 m2 / g to 300 m2 / g. In some implementations, the 3DG carbon fragments may be characterized by a graphene to amorphous carbon ratio between about 1% and 95%. In some implementations, the 3DG carbon fragments may be characterized by a carbon purity of at least 99.9%. The 3DG carbon fragments may be characterized by an electrical conductivity of between about 500 S / m and about 20,000 S / m when compressed at pressure of about 12,000 pounds per square inch (“psi”). Without being bound by any particulartheory, the 3DG carbon fragments including mesoporous nanoparticles, as described herein, may improve the mechanical strength of the gas permeable membranes.
[0055] In some implementations, mesoporous nanoparticles 200 may include a plurality of interconnected crinkled 3D graphene layers, a plurality of non-hollow carbonaceous spherical particles (“NHCS”), flat graphene, wrinkled graphene, a plurality of carbon nanotubes (“CNTs”), or a plurality of carbon nano-onions (“CNOs”). In some implementations, mesoporous nanoparticles 200 may include wavy or flexible graphene layers that resemble crinkled paper and may be produced using microwave processes. The graphene layers may be flexible as they may be fused with each other at sp3type defects in the sp2graphene lattice structure.
[0056] Figure 3A shows a schematic diagram of 3DG carbon fragments 301 having porous interconnected graphene nanoplatelets (“GNP”) and a scaffolded structure, according to some implementations. Figure 3B shows a TEM micrograph 302 of the 3DG carbon fragments 301, according to some implementations. As shown, the 3D few-layer graphene (“FLG”) flakes 301’, may be seen at 50 nm scale. FLG may refer to about 10 layers of graphene generally configured in a stacked orientation. Those skilled in the art will appreciate that the micrographs are shown by way of example only, and that other scales may exist without departing from the scope and spirit of the present implementations.
[0057] Figure 3C shows a SEM micrograph of 3DG carbon fragments 303, according to other implementations. In some instances, plasma-based processing conditions applied or performed in a reactor including a microwave reactor may be tuned with a high degree of tunability to achieve 3DG carbon fragments and graphene-on-graphene densification to yield the complex 3DG carbon fragments 303. The 3DG carbon fragments 303 may be surface etched using methods including CO2etching to create pores on the external surface of the agglomerates 303’ and to increase the surface area of the 3DG carbon fragments.
[0058] In some implementations, the 3DG carbon fragments may be characterized by a Raman spectroscopy signature having an ID / IG ratio between approximately 0.95 and approximately 1.05. In some implementations, the 2D / G ratio associated with the Raman spectra of ozone treated 3DG carbon fragments may be about 0.7, which suggests that the graphene flakes in the 3DG carbon fragments include multi-layer graphene.
[0059] In some implementations, the 3DG carbon fragments may be used without any post-production processing steps. In other implementations, the 3DG carbon fragments may be subject to post-product processing steps. Examples of post-production processing stepsmay include one or more of mechanical processing steps including ball milling, grinding, attrition milling, micro fluidizing, or other processes to reduce particle size. Post-production processing steps may also include one or more exfoliation processes including sheer mixing, chemical etching, oxidizing (e.g., Hummer method), thermal annealing, doping by adding elements during annealing (e.g., sulfur, nitrogen), steaming, filtering, or lyophilizing, or other processes. Some other examples of post-production processing may include sintering processes including one or more of spark plasma sintering (“SPS”), direct current sintering, microwave sintering, or ultraviolet (“UV”) sintering, which may be conducted at high pressure and temperature in an inert gas. In some other implementations, multiple postproduction processing methods may be used in any combination to achieve desired physical and chemical properties of the 3DG carbon fragments. For example, post-production processing may yield functionalized 3DG carbon fragments as disclosed herein.
[0060] In some implementations, the 3DG carbon fragments may be subjected to postproduction thermal annealing or sintering in an inert environment including nitrogen or argon and at elevated temperatures, and at atmospheric pressure, or under vacuum. Post-production processing temperatures may range from approximately 500°C to 2500°C, or from approximately 500°C to 1500°C, or from approximately 800°C to 1500°C, or from approximately 800°C to 1200°C, or from approximately 800°C to 1000°C, or from approximately 2000°C to 2400°C, or approximately at 800°C, or approximately at 1000°C, or approximately at 1500°C, or approximately at 2000°C, or approximately at 2400°C.
[0061] In some implementations, 3DG carbon fragments may be doped with silicon during the production of 3DG carbon fragments in a microwave reactor. Vaporized silicon precursors including one or more of hexamethyl disiloxane (“HMDSO”), hexamethyldisilazane (“HMDSN”), or other similar precursors, may be injected into the microwave reactor along with a hydrocarbon feedstock to produce 3DG carbon fragments functionalized with silicon.
[0062] In some implementations, nano-silica particles or nano-silica clusters may be covalently grafted on the surface of the 3DG carbon fragments. In some instances, 3DG carbon fragments surface functionalized with oxygen, for example, using ozone oxidation as previously described herein, may be treated with silica precursors including tetraethyl orthosilicate (“TEOS”), or similar precursors, to initiate the formation and growth of nano-silica at the oxygen sites on the surface of oxidized 3DG carbon fragments. In some otherinstances, functional groups other than oxygen containing functional groups may be first anchored on the surface of 3DG carbon fragments to initiate the growth of silica.
[0063] In some implementations, 3DG carbon fragments may include agglomerates of primary carbon particles that include carbon nano-onions (“CNOs”) and other allotropes of carbon including graphene. The primary carbon nanoparticles may include two or more connected multi-walled spherical fullerenes (“MWSF”). CNOs or multi-walled fullerenes are carbon nanoparticles, generally spherical in shape, and may include multiple concentric shells including graphene that define a plurality of porous regions or zones nested within each other. The primary carbon nanoparticles may be characterized by a high degree of order (e.g., a Raman signature with an ID / IG ratio from 0.95 to 1.05), and a high purity (e.g., the ratio of carbon to other elements, other than H, is greater than 99.9%). Layers of graphene may coat the connected CNOs in each primary carbon nanoparticle. The one or more shells and carbonaceous regions may include sp2-hybridized carbon (indicative of graphene) and may have minor islands of amorphous sp3-hybridized carbon.
[0064] Synthesis and / or growth of 3DG carbon fragments including CNOs may be produced by thermal cracking of hydrocarbon feedstock as disclosed in one or more of U. S. Pat. No. 9,862,602, U. S. Pat. No. 10,112,837, U. S. Pat. No. 11,053,121, and U. S. Pat. Pub. No. 2021 / 0292170, all of which are incorporated by reference herein in their respective entireties. The 3DG carbon fragments including CNOs may also be surface functionalized as previously described herein.
[0065] Figure 4A shows a schematic diagram of a primary carbon nanoparticle 400A in 3DG carbon fragments, according to some implementations. The primary carbon nanoparticle 400A includes an inner region 411 surrounded by an outer region 412. The outer region 412 includes an outer boundary 410 of the primary carbon particle 400A. The inner region 411 may include a plurality of first pores 401 dispersed therein, and the outer region 412 may include a plurality of second pores 402 dispersed therein. The inner region 411 and outer region 412 may be interconnected by at least some of the first pores 401. The inner region 411 may be associated with a first pore density, and the outer region 412 may be associated with a second pore density that is different than the first pore density. The primary carbon nanoparticles may be characterized by a size or principal dimension (diameter, length, width) of less than approximately 200 nm.
[0066] Figure 4B shows a TEM image 400B of a carbon agglomerate 430, according to some implementations. As shown, the carbon agglomerate 430 may include a plurality ofprimary carbon nanoparticles 432 that resemble a “string-of-pearls.” In some implementations, the size or principal dimension of carbon aggregate 430 may be between about 50 nm and 500 nm. Primary carbon nanoparticles 432 may be of any shape, including one or more of spherical, spheroidal, dumbbell, cylindrical, elongated cylindrical type, rectangular prism, disk, wire, or irregular. In some implementations, the primary nanoparticles 432 may be formed of concentric, well-ordered spheres of sp2-hybridized carbon atoms. Within primary nanoparticles 432, pore sizes may decrease along a radial direction from the center 416 of the particle to the outer boundary of the particle. In some example implementations, a multi-shell CNO primary particle may be characterized by a range of pore sizes and pore distributions in each region. The primary nanoparticles 432 and / or carbonaceous layers may also include one or more of few layer graphene (“FLG”) interconnected platelets, multi-layer graphene (“MLG”) interconnected platelets, graphite, carbon nanotubes (“CNTs”), flat graphene, or wrinkled graphene. The primary carbon nanoparticles 432 may be characterized as non-hollow carbon spherical particles. In some other implementations, the primary carbon nanoparticles 432 may also include tri-zone particles.
[0067] Figures 4C shows a TEM image of 3-dimensional carbon agglomerates 400C, according to some implementations. The agglomerates 400C may be dispersed in a precursor solution associated with a flash spinning process used to produce the non-woven fabric including a web of polymer fibers. In some instances, 3DG carbon fragments including agglomerates 400C may be functionalized with one or more of oxygen containing functional groups, other functional groups, or atoms, as previously described.
[0068] Figure 5 shows a diagram of another primary carbon nanoparticle 500 in 3DG carbon fragments, according to some implementations. The primary carbon nanoparticle 500 may include a first zone 551 nested within a second zone 552, which in turn is nested within a third zone 553. The first zone 551 may include pores having a size or principal dimension (diameter, length width) of less than approximately 40 nm, the second zone 552 may include pores having a principal dimension of less than approximately 35 nm, and the third zone 553 may include pores having a principal dimension of less than approximately 30 nm. In some instances, the pores 561 within the first zone 551 may be characterized as macropores, the pores 562 within the second zone may be characterized as mesopores, and the pores 563 within the third zone 553 may be characterized as micropores.
[0069] In some instances, the principal dimension DI of first zone 551 may be less than approximately 100 nm, the principal dimension D2 of second zone 552 may be less than approximately 150 nm, and the principal dimension D3 of third zone 553 may be approximately 200 nm. The relative dimensions, porosities, and electrical conductivities of the first zone 551, the second zone 552, and the third zone 553 may be tuned by tuning reactor operating conditions to obtain desired particle or aggregate structure, porosity, and particle density. The first zone 551 may have a density of carbonaceous material of less than approximately 1 g / cc. The third zone 553 is bounded by an outer shell 555 and may have a density of carbonaceous material between approximately less than 1 g / cc and 3.5 g / cc. The second zone 552 may have a density of carbonaceous material between approximately 0.5 g / cc and 3 g / cc. The one or more shells and carbonaceous regions may include sp2-hybridized carbon (indicative of graphene) and may have minor islands of amorphous sp3-hybridized carbon.
[0070] Figure 6 shows a scanning transmission electron microscopy (“STEM”) micrograph 600 of 3DG carbon fragments, according to some implementations. As shown in micrograph 600, 3DG carbon fragments may include one or more graphene flakes 601 (also referred to herein as “flaky graphene”) that may include few layers of graphene or multiple layers of graphene. Additionally, graphene flakes 601 may be characterized by a wavy or wrinkled morphology. Graphene flakes 601 may include carbon regions 602, which are represented as bright areas in micrograph 600.
[0071] Figure 7 shows a schematic diagram 700 of a composite gas permeable membrane, according to some implementations. In some implementations, a composite gas permeable membrane may include one or more carbon-based layers 701 including a plurality of three-dimensional graphene fragments (“3DG carbon fragments”), and a plurality of polymer membranes 702. In some instances, the one or more carbon-based layers 701 may be sandwiched between two adjacent polymer membranes 701 and fused to the polymer membranes using one or more of Joule heating or hot pressing. Heat treatment processes including Joule heating or hot pressing may melt the polymer membranes 702 and meld the polymer membranes 702 together with the one or more carbon-based layers to form the composite gas permeable membrane. In general, Joule heating produces localized heat by passing an electric current through conductive material, for example, the one or more carbonbased layers including the 3DG carbon fragments. In contrast, bulk heating may compromise the porosity and / or permeability of the gas permeable membranes described herein.
[0072] In some other instances, the plurality of polymer membranes 702 associated with a composite gas permeable membrane may include thermoplastic polymers. In some other instances, the thermoplastic polymers may include one or more of polyethylene, high density polyethylene (“HDPE”), polypropylene, nylon, polyester, polyurethane, or polyvinylidene fluoride. In some implementations, the 3DG carbon fragments may include one or more allotropes of carbon including graphene. In some instances, the allotropes of carbon include one or more carbon nanotubes (“CNT”), carbon nano onions (“CNOs”), carbon nanofibers, or fullerenes.
[0073] Figure 8 shows a schematic diagram 800 of another composite gas permeable membrane, according to some implementations. In some implementations, a composite gas permeable membrane may include one or more carbon-based layers 801 including a plurality of three-dimensional graphene fragments (“3DG carbon fragments”), and one or more polymer membranes 802. In some instances, the one or more carbon-based layers 801 may be disposed on a surface associated with the one or more polymer membranes 802 and fused using one or more of Joule heating or hot pressing. Heat treatment processing including Joule heating or hot pressing may provide a composite gas permeable membrane characterized by a strong adhesion or bond strength between the carbon-based layer 801 and the polymer membrane 802, thereby minimizing delamination of the carbon-based layers 801 from the polymer membranes 802. In some instances, the one or more carbon-based layers may be formed by depositing a suspension including 3DG carbon fragments on the one or more polymer membranes 802 under vacuum to draw the suspension through the one or more polymer membranes 802. The solvent associated with the suspension including 3DG carbon fragments may be removed by drying.
[0074] In some other implementations, 3DG carbon fragments associated with composite gas permeable membranes described with reference to Figure 8 may include one or more allotropes of carbon, including graphene. In some instances, the allotropes of carbon include one or more carbon nanotubes (“CNT”), carbon nano onions (“CNOs”), carbon nanofibers, or fullerenes. In some examples, the one or more polymer membranes include thermoplastic polymers. In some other examples, the thermoplastic polymers may include one or more of polyethylene, high density polyethylene (“HDPE”), polypropylene, nylon, polyester, polyurethane, or polyvinylidene fluoride.
[0075] Harnessing the full potential of 3DG carbon fragments requires uniform dispersion of 3DG carbon fragments in hydrophilic and polar systems, for example in water,to mitigate agglomeration of the 3DG carbon fragments for example, in a precursor solution associated with a flash spinning process. Surface functionalization of 3DG carbon fragments may disperse, size separate, and stabilize the 3DG carbon fragments in a solvent, for example in a solvent associated with a flash spinning process. Accordingly, in some other implementations, 3DG carbon fragments may be treated to incorporate surface functional groups to tune properties associated with 3DG carbon fragments and properties associated with the gas permeable membranes. In some instances, ozone oxidation of 3DG carbon fragments may produce oxygen-containing functional groups in and / or on the surfaces of 3DG carbon fragments described herein. The oxygen containing functional groups on the 3DG carbon fragments may include one or more of epoxide (C-O-C, two carbons and oxygen forming a three-membered ring structure), hydroxyl (-OH), ether (C-O-C), ketone (O-C=O), or carboxylic acid (-COOH) groups. One or more of the functional groups described herein may be disposed as surface functional groups on 3DG carbon fragments. In other implementations, one or more of the functional groups described herein may be disposed within the porous structure of the 3DG carbon fragments.
[0076] In some implementations, 3DG carbon fragments may be functionalized in situ -that is, within the reactor during the production of 3DG carbon fragments. In some implementations, 3DG carbon fragments may be functionalized using separate postproduction processing steps. For example, 3DG carbon fragments may be treated with ozone to surface-oxidize the carbons. In some other implementations, 3DG carbon fragments may be subjected to ozone oxidation in a fluidized bed reactor. A reactive ozone-treated oxidant gas may fluidize a bed of 3DG carbon fragments at suitable process conditions to generate various oxygen-containing species or functional groups (as described above) on the surface of the 3DG carbon fragments.
[0077] In some other implementations, the 3DG carbon fragments including oxygen functional groups as described above may be further post-processed to functionalize the oxidized surface of the carbon with silane through a modification of the Stobbe colloidal silica synthesis. Furthermore, the surfaces of 3DG carbon fragments may be functionalized with silica, oxygen or nitrogen containing species which form bonds with the polymer fibers, thus improving adhesion and providing strong binding to enhance the strength of the gas permeable membranes described herein.
[0078] As previously described herein, 3DG carbon graphene fragments, when incorporated into a polymer matrix, may provide a barrier to liquid water diffusion throughthe polymer matrix. In some instances, 3DG carbon fragments characterized by a high aspect ratio (also referred to herein as a ratio of length to width, or a ratio of length to height) may create a tortuous path for water molecules in a polymer matrix. In some instances, an aspect ratio associated with 3DG carbon fragments may be between about 10 and about 100.Additional details are provided below with reference to Figure 9. In substantially non-porous polymer membranes, 3DG carbon fragments may significantly reduce water diffusion, as the 3DG carbon fragments may disrupt the direct pathway for water transport through a polymer matrix.
[0079] In some implementations, the 3DG carbon fragments described herein may be surface functionalized to improve hydrophilic properties associated with the 3DG carbon fragments. In some instances, 3DG carbon fragments including hydrophilic properties may be dispersed in a polymer matrix associated with the gas permeable membrane to separate one or more gases from a mixture of gases. Figure 9 shows a schematic diagram 900 of a composite gas permeable membrane, according to some implementations. A gas permeable membrane may include a polymer matrix 901 including 3DG carbon fragments shown as discrete fragments, for illustrative purposes. A plurality of 3DG carbon fragments 902, surface functionalized to improve hydrophilic properties of the 3DG carbon fragments may be dispersed in polymer matrix 901 and configured as a staggered structure to introduce a tortuous pathway 903. Tortuous pathway 903 may increase the residence time of a mixture of gases and improve separation efficiency of one gas component, for example, oxygen, from a mixture of gases, water vapor, and oxygen. Without being bound by any particular theory, the high surface area and tunable surface properties of 3DG carbon fragments may produce gas-permeable membranes with variable hydrophilicity to selectively enhance vapor absorption, for example, water vapor absorption, while permitting other gases, for example, oxygen to pass through the gas permeable membrane. In the absence of 3DG carbon fragments, no measurable gas separation may be realized in a polymer membrane that may allow all components in a gas mixture to pass through the membrane in a “straight-through” pathway 904.
[0080] As previously described herein reference to Figures 1A-1B, the web 101 of polymer fibers 102 including the carbon-based material may be based on, or made, using a flash spinning process. In general, a thermoplastic polymer may be dissolved in a suitable solvent. Any one of the 3DG carbon fragments previously described herein may be dispersed in the solvent. Examples of solvents may include one or more of aromatic hydrocarbonsincluding benzene and toluene, aliphatic hydrocarbons including butane, pentane, hexane, heptane, octane, and their isomers and homologs, alicyclic hydrocarbons including cyclohexane, unsaturated hydrocarbons, halogenated hydrocarbons including trichlorofluoromethane, methylene chloride, carbon tetrachloride, dichloroethylene, chloroform, ethyl chloride, methyl chloride, alcohols, esters, ethers, ketones, nitriles, amides, fluorocarbons, sulfur dioxide; carbon dioxide; carbon disulfide, nitromethane, water, or combinations of the above, among other similar non-limiting examples. The thermoplastic polymer is dissolved at elevated pressure and temperature and is extruded through a nozzle. As the dissolved polymer is extruded from the nozzle, the rapid pressure drop causes the thermoplastic polymer to crash out of solution and form the web of fibers. The residual solvent may be subsequently dried and removed from the web.
[0081] The surface properties of the 3DG carbon fragments may be tuned to prevent “lumping” of the 3DG carbon fragments in the solvent. The solvent mixture or spin fluid mixture may then be heated under elevated pressure in a pressure vessel including a nozzle. The contents within the pressure vessel are then released through the nozzle. As the mixture or solution “flashes” out of the nozzle, a polymeric web of polymer fibers including the 3DG carbon fragments may be formed. In some instances, the web of polymer fibers may be referred to as a web of film-fibril strands of a polymer. The web of polymer fibers may be disposed on a mat or backing material to form a flat sheet of fibers, which may be processed to yield a non-woven fabric of the web of polymer fibers including the 3DG carbon fragments.
[0082] As used herein, a phrase referring to “at least one of” or “one or more of’ a list of items refers to any combination of those items, including single members. For example, “at least one of: a, b, or c” is intended to cover the possibilities of: a only, b only, c only, a combination of a and b, a combination of a and c, a combination of b and c, and a combination of a and b and c. Unless otherwise specified in this disclosure, for construing the scope of the term “about” or “approximately,” the error bounds associated with the values (dimensions, operating conditions etc.) disclosed is ± 10% of the values indicated in this disclosure. The error bounds associated with the values disclosed as percentages is ± 1% of the percentages indicated. The word “substantially” used before a specific word includes the meanings “considerable in extent to that which is specified,” and “largely but not wholly that which is specified.”
[0083] Various modifications to the implementations described in this disclosure may be readily apparent to persons having ordinary skill in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the implementations shown herein but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.
[0084] Additionally, various features that are described in this specification in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. As such, although features may be described above in combination with one another, and even initially claimed as such, one or more features from a claimed combination can in some cases be removed from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.
[0085] Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Further, the drawings may schematically depict one more example processes in the form of a flowchart or flow diagram. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In some circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single product or packaged into multiple products.
Claims
CLAIMSWhat is claimed is:
1. A gas permeable membrane including:a non-woven fabric including a web of polymer fibers; anda carbon-based material including a plurality of three-dimensional graphene fragments (3DG carbon fragments) disposed in at least some of the polymer fibers, wherein at least some of the 3DG carbon fragments are oriented at a non-zero surface angle relative to an external surface of a respective polymer fiber.
2. The gas permeable membrane of claim 1, wherein each of the 3DG carbon fragments includes:a first end anchored within a corresponding polymer fiber; andan opposing second end disposed at a distance from the external surface of the corresponding polymer fiber.
3. The gas permeable membrane of claim 1, wherein the web of polymer fibers including the carbon-based material is based on a flash spinning process.
4. The gas permeable membrane of claim 3, wherein the non-zero surface angle is based on application of a charge to a polymer solution associated with the flash spinning process.
5. The gas permeable membrane of claim 1, wherein the gas permeable membrane is selectively permeable to water vapor.
6. The gas permeable membrane of claim 1, wherein the gas permeable membrane is selectively permeable to a gas associated with one or more of a mixture of gases or a gas-liquid mixture.
7. The gas permeable membrane of claim 1, wherein the polymer fibers include thermoplastic polymer fibers.
8. The gas permeable membrane of claim 7, wherein the thermoplastic polymer fibers include fibers made of one or more of polyethylene, high density polyethylene (HDPE), polypropylene, Nylon, polyester, polyurethane, or polyvinylidene fluoride.
9. The gas permeable membrane of claim 1, wherein the 3DG carbon fragments further include amorphous graphitic carbon particles.
10. The gas permeable membrane of claim 1, wherein the 3DG carbon fragments include one or more allotropes of carbon including graphene.
11. The gas permeable membrane of claim 10, wherein the one or more allotropes of carbon include one or more of carbon nanotubes (CNT), carbon nano onions (CNOs), carbon nanofibers, or fullerenes.
12. The gas permeable membrane of claim 1, wherein the 3DG carbon fragments comprise include flaky graphene that includes one or more interconnected bundles of electrically conductive graphene layers.
13. The gas permeable membrane of claim 12, wherein the graphene layers are arranged as one or more stacks connected to each other to define a 3D porous scaffold structure including mesopores.
14. The gas permeable membrane of claim 13, wherein the one or more stacks of graphene layers are disposed substantially orthogonal to each other.
15. The gas permeable membrane of claim 12, wherein the graphene layers are characterized by a linear dimension of between approximately 50 nm and 200 nm.
16. The gas permeable membrane of claim 12, wherein the graphene layers include one or more of single layer graphene (SLG), few layer graphene (FLG), or many layer graphene (MLG).
17. The gas permeable membrane of claim 1, wherein the 3DG carbon fragments are characterized by a Raman spectroscopy signature having an ID / IG ratio of less than 1.
18. The gas permeable membrane of claim 1, wherein the 3DG carbon fragments are characterized by a Brunauer-Emmett-Teller (BET) surface area between approximately 50 m2 / g and 500 m2 / g measured using nitrogen gas.
19. The gas permeable membrane of claim 1, wherein the 3DG carbon fragments are characterized by a graphene to amorphous graphitic carbon ratio of between approximately 1% and 95%.
20. The gas permeable membrane of claim 1, wherein the 3DG carbon fragments are characterized by an electrical conductivity of between approximately 500 S / m and 20,000 S / m when compressed at pressure of approximately 12,000 pounds per square inch (psi).
21. The gas permeable membrane of claim 1, wherein the 3DG carbon fragments include one or more of oxygen containing surface functional groups, nano-silica particles, or nano-silica surface functional groups.
22. The gas permeable membrane of claim 21, wherein the oxygen containing surface functional groups includes one or more of epoxide (C-O-C), hydroxyl (-OH), ether (C-O-C), ketone (O-C=O), or carboxylic acid (-COOH) groups.
23. A gas permeable membrane including:a non-woven fabric including a web of polymer fibers; anda carbon-based material including a plurality of three-dimensional graphene fragments (3DG carbon fragments), wherein at least some of the 3DG carbon fragments are embedded within at least some of the polymer fibers.
24. The gas permeable membrane of claim 23, wherein the carbon-based material further includes amorphous graphitic carbon particles.
25. The gas permeable membrane of claim 23, wherein the web of polymer fibers is based on a flash spinning process.
26. The gas permeable membrane of claim 23, wherein the web of polymer fibers includes thermoplastic polymer fibers.
27. A gas permeable membrane including:a non-woven fabric including a web of polymer fibers; anda carbon-based material including a plurality of three-dimensional graphene fragments (3DG carbon fragments), wherein at least some of the 3DG carbon fragments are disposed as a bridge connecting adjacent polymer fibers.
28. The gas permeable membrane of claim 27, wherein the carbon-based material further includes amorphous graphitic carbon particles.
29. The gas permeable membrane of claim 27, wherein the polymer fibers include thermoplastic polymer fibers.
30. A composite gas permeable membrane including:one or more carbon-based layers each including a plurality of three-dimensional graphene fragments (3DG carbon fragments); anda plurality of polymer membranes, wherein the one or more carbon-based layers are sandwiched between two adjacent polymer membranes and fused to the adjacent polymer membranes based on one or more of Joule heating or hot pressing.
31. The composite gas permeable membrane of claim 30, wherein at least some of the plurality of polymer membranes include thermoplastic polymers.
32. The composite gas permeable membrane of claim 31, wherein the thermoplastic polymers include one or more of polyethylene, high density polyethylene (HDPE), polypropylene, nylon, polyester, polyurethane, or poly vinylidene fluoride.
33. The composite gas permeable membrane of claim 30, wherein the 3DG carbon fragments include one or more allotropes of carbon including graphene.
34. The composite gas permeable membrane of claim 33, wherein the allotropes of carbon include one or more carbon nanotubes (CNT), carbon nano onions (CNOs), carbon nanofibers, or fullerenes.
35. A composite gas permeable membrane including:one or more carbon-based layers including a plurality of three-dimensional graphene fragments (3DG carbon fragments); andone or more polymer membranes, wherein the one or more carbon-based layers are disposed on a surface associated with the one or more polymer membranes and fused to the surface associated with the one or more polymer membranes based on one or more of Joule heating or hot pressing.
36. The composite gas permeable membrane of claim 35, wherein the 3DG carbon fragments include one or more allotropes of carbon including graphene.
37. The composite gas permeable membrane of claim 36, wherein the allotropes of carbon include one or more carbon nanotubes (CNT), carbon nano onions (CNOs), carbon nanofibers, or fullerenes.
38. The composite gas permeable membrane of claim 35, wherein the one or more polymer membranes include thermoplastic polymers.
39. The composite gas permeable membrane of claim 38, wherein the thermoplastic polymers include one or more of polyethylene, high density polyethylene (HDPE), polypropylene, nylon, polyester, polyurethane, or polyvinylidene fluoride.