# US 2014/0154941 A1 · Unitary graphene matrix composites containing carbon or graphite fillers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0154941 A1 - Document ID: US20140154941A1 - Status: Published application - Kind: A1 - Application number: 13/694,468 - Filed: 2012-12-05 - Published: 2014-06-05 - Earliest claimed: 2012-12-05 - Assignees: Nanotek Instruments, Inc. - Inventors: Aruna Zhamu; Mingchao Wang; Wei Xiong; Bor Z. Jang - Web page: https://patentgrep.com/patent/US20140154941A1 ## CPC - H01B 1/04: mainly consisting of carbon-silicon compounds, carbon or silicon - B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites - Y10S 977/734: Fullerenes, i.e. graphene-based structures, such as nanohorns, nanococoons, nanoscrolls or fullerene-like structures, e.g. WS2 or MoS2 chalcogenide nanotubes, planar C3N4, etc. - Y10S 977/842: for carbon nanotubes or fullerenes - Y10T 428/249955: Void-containing component partially impregnated with adjacent component - Y10T 428/292: In coating or impregnation - Y10T 442/2631: Coating or impregnation provides heat or fire protection - H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K}) - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A unitary graphene matrix composite comprising: (a) a unitary graphene matrix containing an oxygen content of 0.001% to 10% by weight, obtained from heat-treating a graphene oxide gel at a temperature higher than 100° C. and contains no discrete graphene platelets derived from the graphene oxide gel; (b) a carbon or graphite filler phase selected from carbon or graphite fiber, carbon or graphite nano-fiber, carbon nano-tube, carbon nano-rod, meso-phase carbon particle, meso-carbon micro-bead, exfoliated graphite flake with a thickness greater than 100 nm, exfoliated graphite or graphite worm, coke particle, needle coke, carbon black or acetylene black particle, activated carbon particle, or a combination thereof. The carbon or graphite filler phase is preferably in a particulate, filamentary, or rod-like form dispersed in and bonded by the unitary graphene matrix. This composite exhibits a combination of exceptional thermal conductivity, electrical conductivity, mechanical strength, surface hardness, and scratch resistance. ## Claims ### Claim 1 A unitary graphene matrix composite comprising: (a) A unitary graphene matrix containing closely packed and chemically bonded graphene planes having an inter-graphene plane spacing of 0.335 to 0.40 nm and an oxygen content of 0.001% to 10% by weight, which unitary graphene matrix is obtained from heat-treating a graphene oxide gel at a temperature higher than 100° C. and contains no discrete graphene platelets derived from said graphene oxide gel; and (b) A carbon or graphite filler phase selected from a carbon or graphite fiber, carbon or graphite nano-fiber, carbon nano-tube, carbon nano-rod, meso-phase carbon particle, meso-carbon micro-bead, exfoliated graphite flake with a thickness greater than 100 nm, exfoliated graphite or graphite worm, coke particle, needle coke, carbon black or acetylene black particle, activated carbon particle, or a combination thereof; wherein said carbon or graphite filler phase occupies a weight fraction of 0.01% to 99% based on the total composite weight and said carbon or graphite filler phase is in a particulate, filamentary, or rod-like form dispersed in said unitary graphene matrix. ### Claim 2 (depends on 1) The unitary graphene matrix composite of claim 1, wherein said chemically bonded graphene planes are parallel to one another. ### Claim 3 (depends on 1) The unitary graphene matrix composite of claim 1, wherein said unitary graphene matrix contains no complete grain boundary therein. ### Claim 4 (depends on 1) The unitary graphene matrix composite of claim 1, wherein said carbon or graphite filler is chemically bonded by said unitary graphene matrix. ### Claim 5 (depends on 1) The unitary graphene matrix composite of claim 1, having a physical density of at least 1.5 g/cm3 or a porosity level lower than 20%. ### Claim 6 (depends on 1) The unitary graphene matrix composite of claim 1, having a physical density of at least 1.7 g/cm3 or a porosity level lower than 10%. ### Claim 7 (depends on 1) The unitary graphene matrix composite of claim 1, wherein the chemically bonded graphene planes contain a combination of sp2 and sp3 electronic configurations. ### Claim 8 (depends on 1) The unitary graphene matrix composite of claim 1, wherein said carbon or graphite filler is in a form of porous woven fabric, porous non-woven fabric, porous mat, or porous paper, and said composite is made by impregnating said porous woven fabric, porous non-woven fabric, porous mat, or porous paper with said graphene oxide gel prior to heat treating. ### Claim 9 (depends on 1) The unitary graphene matrix composite of claim 1, wherein said carbon or graphite filler is in a form of fiber yarns or fiber bundles impregnated with said graphene oxide gel and said composite is made by forming said fiber yarns or bundles into a desired shape prior to heat treating. ### Claim 10 (depends on 9) The unitary graphene matrix composite of claim 9, wherein said desired shape is selected from a unidirectional, bi-directional, multi-directional, angle-plied, woven, or filament-wound shape. ### Claim 11 (depends on 1) The unitary graphene matrix composite of claim 1, wherein said carbon or graphite filler phase occupies a weight fraction from 0.1% to 70% based on the total composite weight and said unitary graphene matrix forms a continuous phase. ### Claim 12 (depends on 1) The unitary graphene matrix composite of claim 1, wherein the heat-treating temperature is from 100° C. to 1,000° C. and said composite has a thermal conductivity greater than 400 W/mK and/or electrical conductivity greater than 1,000 S/cm. ### Claim 13 (depends on 1) The unitary graphene matrix composite of claim 1, wherein the heat-treating temperature is from 1,000° C. to 1,500° C. and said composite has a thermal conductivity greater than 600 W/mK and/or electrical conductivity greater than 2,000 S/cm. ### Claim 14 (depends on 1) The unitary graphene matrix composite of claim 1, wherein the heat-treating temperature is from 1500° C. to 2,500° C. and said composite has a thermal conductivity greater than 1,000 W/mK and/or electrical conductivity greater than 3,000 S/cm. ### Claim 15 (depends on 1) The unitary graphene matrix composite of claim 1, wherein the heat-treating temperature is from 2,500° C. to 3,250° C. and said composite has a thermal conductivity greater than 1,500 W/mK and/or electrical conductivity greater than 5,000 S/cm. ### Claim 16 (depends on 1) The unitary graphene matrix composite of claim 1, wherein said unitary graphene matrix has an oxygen content from 0.01% to 5% by weight. ### Claim 17 (depends on 1) The unitary graphene matrix composite of claim 1, wherein said graphene oxide gel is composed of graphene oxide molecules dispersed in an acidic medium having a pH value of no higher than 5 and said graphene oxide molecules have an oxygen content no less than 20% by weight while in a gel state. ### Claim 18 (depends on 1) The unitary graphene matrix composite of claim 1, wherein said graphene oxide gel is obtained by immersing a graphitic material in a powder or fibrous form in an oxidizing liquid medium in a reaction vessel at a reaction temperature for a length of time sufficient to obtain a graphene oxide gel composed of graphene oxide molecules dispersed in the liquid medium and said graphene oxide molecules have an oxygen content no less than 20% by weight and a molecular weight less than 43,000 g/mole while in a gel state. ### Claim 19 (depends on 17) The unitary graphene matrix composite of claim 17, wherein said graphene oxide molecules have a molecular weight less than 4,000 g/mole while in a gel state. ### Claim 20 (depends on 17) The unitary graphene matrix composite of claim 17, wherein said graphene oxide molecules have a molecular weight between 200 g/mole and 4,000 g/mole while in a gel state. ### Claim 21 (depends on 1) The unitary graphene matrix composite of claim 1, which is produced by (a) depositing or dispensing a mixture of graphene oxide gel and carbon or graphite phase onto a substrate surface or into a mold cavity, (b) removing a residual liquid from said mixture to form a precursor composite; and (c) subjecting said precursor composite to a heat treatment at a temperature of at least 150° C. for thermal reduction and/or re-graphitization of the graphene oxide to form a continuous graphene matrix. ### Claim 22 (depends on 21) The unitary graphene matrix composite of claim 21, wherein said heat treatment temperature is at least 1,500° C. ### Claim 23 (depends on 21) The unitary graphene matrix composite of claim 21, wherein said heat treatment temperature is at least 2,500° C. ### Claim 24 (depends on 1) The unitary graphene matrix composite of claim 1, wherein said graphene oxide gel is produced from oxidation of a graphitic material selected from natural graphite, artificial graphite, meso-phase carbon, meso-phase pitch, meso-carbon micro-bead, soft carbon, hard carbon, coke, carbon fiber, carbon nano-fiber, carbon nano-tube, or a combination thereof. ### Claim 25 (depends on 1) The unitary graphene matrix composite of claim 1, wherein said filler contains elongated-shape or filamentary particles selected from carbon or graphite fibers, carbon or graphite nano-fibers, carbon nano-tubes, carbon nano-rods, and/or needle coke particles which have a length and a diameter or thickness, and said elongated-shape or filamentary particles are aligned along a length direction so that the composite is anisotropic having an anisotropy ratio greater than 10, wherein the anisotropy ratio is defined as a length-direction property-to-thickness-direction property ratio and said property is selected from electrical conductivity, thermal conductivity, strength, or modulus. ### Claim 26 (depends on 25) The unitary graphene matrix composite of claim 25, wherein said anisotropy ratio is greater than 100. ### Claim 27 (depends on 25) The unitary graphene matrix composite of claim 25, wherein said anisotropy ratio is less than 10. ### Claim 28 (depends on 25) The unitary graphene matrix composite of claim 25, wherein said anisotropy ratio is less than 2. ### Claim 29 (depends on 1) The unitary graphene matrix composite of claim 1, having a Rockwell hardness value greater than 80. ### Claim 30 (depends on 1) The unitary graphene matrix composite of claim 1, having an electrical conductivity greater than 1,500 S/cm, a thermal conductivity greater than 600 W/mK, a physical density greater than 1.8 g/cm3, and/or a tensile strength greater than 80 MPa. ### Claim 31 (depends on 1) The unitary graphene matrix composite of claim 1, having an electrical conductivity greater than 3,000 S/cm, a thermal conductivity greater than 1,000 W/mK, a physical density greater than 1.9 g/cm3, and/or a tensile strength greater than 120 MPa. ### Claim 32 (depends on 1) The unitary graphene matrix composite of claim 1, having an electrical conductivity greater than 5,000 S/cm, a thermal conductivity greater than 1,500 W/mK, a physical density greater than 2.0 g/cm3, and/or a tensile strength greater than 150 MPa. ### Claim 33 A unitary graphene matrix composite comprising: (a) A unitary graphene matrix containing graphene planes having an inter-graphene plane spacing of 0.335 to 0.40 nm and an oxygen content less than 1% by weight, which unitary graphene matrix is obtained from heat-treating a graphene oxide gel at a temperature higher than 500° C. and contains no discrete graphene platelets derived from said graphene oxide gel; (b) A carbon or graphite filler phase selected from a carbon or graphite fiber, carbon or graphite nano-fiber, carbon nano-tube, carbon nano-rod, meso-phase carbon particle, meso-carbon micro-bead, exfoliated graphite flake with a thickness greater than 100 nm, exfoliated graphite or graphite worm, coke particle, needle coke, carbon black or acetylene black particle, activated carbon particle, or a combination thereof; wherein said carbon or graphite filler phase occupies a weight fraction from 1% to 90% based on the total composite weight and said carbon or graphite filler phase is in a particulate, filamentary, or rod-like form dispersed in said unitary graphene matrix which forms a continuous phase. ### Claim 34 (depends on 1) A process for producing the unitary graphene matrix composite of claim 1, said process comprising: (a) preparing a graphene oxide gel having graphene oxide molecules dispersed in a fluid medium, wherein the graphene oxide gel is optically transparent or translucent; (b) mixing said carbon or graphite filler phase in said graphene oxide gel to form a slurry; (c) dispensing said slurry onto a surface of a supporting substrate or a cavity of a molding tool; (d) partially or completely removing said fluid medium from the slurry to form a composite precursor; and (e) heat-treating the composite precursor to form said unitary graphene composite at a temperature higher than 100° C. ### Claim 35 (depends on 1) A process for producing the unitary graphene matrix composite of claim 1, said process comprising: (a) preparing a graphene oxide gel having graphene oxide molecules dispersed in a fluid medium, wherein the graphene oxide gel is optically transparent or translucent; (b) forming said carbon or graphite filler phase into a desired porous shape having pores therein, and impregnating said graphene oxide gel into said pores of the desired porous shape to form an impregnated shape; (c) partially or completely removing said fluid medium from the impregnated shape to form a composite precursor; and (d) heat-treating the composite precursor to form said unitary graphene composite at a temperature higher than 100° C. ### Claim 36 (depends on 35) The process of claim 35, wherein said desired porous shape is a porous woven fabric, porous non-woven fabric, porous mat, or porous paper. ### Claim 37 (depends on 1) A process for producing the unitary graphene matrix composite of claim 1, said process comprising: (a) preparing a graphene oxide gel having graphene oxide molecules dispersed in a fluid medium, wherein the graphene oxide gel is optically transparent or translucent; (b) combining said carbon or graphite filler phase and said graphene oxide gel to form a graphene oxide gel-impregnated shape of fiber yarns or bundles; (c) partially or completely removing said fluid medium from graphene oxide gel-impregnated shape to form a composite precursor; and (d) heat-treating the composite precursor to form said unitary graphene composite at a temperature higher than 100° C. ### Claim 38 (depends on 37) The process of claim 37, wherein said graphene oxide gel-impregnated shape is selected from a unidirectional, bi-directional, multi-directional, angle-plied, woven, or filament-wound shape. ### Claim 39 (depends on 34) The process of claim 34, wherein said graphene oxide gel is prepared by immersing a graphitic material in a powder or fibrous form in an oxidizing liquid to form an optically opaque suspension in a reaction vessel at a reaction temperature for a length of time sufficient to obtain a graphene oxide gel that is optically transparent or translucent, wherein said graphene oxide gel is composed of graphene oxide molecules dispersed in an acidic medium having a pH value of no higher than 5 and said graphene oxide molecules have an oxygen content no less than 20% by weight. ### Claim 40 (depends on 35) The process of claim 35, wherein said graphene oxide gel is prepared by immersing a graphitic material in an oxidizing agent to form an optically opaque suspension and allowing an oxidizing reaction to proceed until an optically transparent or translucent solution is formed, and wherein said graphitic material is selected from natural graphite, artificial graphite, meso-phase carbon, meso-phase pitch, meso-carbon micro-bead, soft carbon, hard carbon, coke, carbon fiber, carbon nano-fiber, carbon nano-tube, or a combination thereof. ### Claim 41 (depends on 34) The process of claim 34, further comprising a step of compressing said composite precursor prior to or during heat treating. ### Claim 42 (depends on 35) The process of claim 35, further comprising a step of compressing said composite precursor prior to or during heat treating. ### Claim 43 (depends on 37) The process of claim 37, further comprising a step of compressing said composite precursor prior to or during heat treating. ### Claim 44 (depends on 34) The process of claim 34, wherein said steps (c) and (d) include feeding a sheet of a solid substrate material from a roller to a deposition zone, dispensing said slurry or suspension onto a surface of said sheet of solid substrate material to form a slurry layer thereon, drying said slurry or suspension to form a dried composite precursor layer deposited on said substrate surface, and collecting composite precursor-deposited substrate sheet on a collector roller. ### Claim 45 (depends on 44) The process of claim 44, further comprising a step of compressing said composite precursor prior to being collected on said collector roller.