▎ 摘　　要

NOVELTY - Graphene matrix composite (C1), comprises: single crystal graphene matrix material, containing closely packed and chemically bonded graphene planes having inter-graphene plane spacing of 0.335-0.4 nm and 0.001-10 wt.% oxygen; carbon or graphite filler phase comprising carbon or graphite fiber, carbon or graphite nanofiber, carbon nanotube, carbon nanorod, mesophase carbon particle, mesocarbon microbead, exfoliated graphite flake, exfoliated graphite or graphite worm, coke particle, needle coke, carbon black or acetylene black particle and/or activated carbon particle. USE - The graphene matrix composite is useful in thermal management applications (e.g. for use as a heat spreader) in a microelectronic device, such as mobile phone, smart phone, notebook computer, tablet, e-book, laptop computer, LCD display, telecommunication device, hand-held computing device such as power tool, portable microelectronic device and light- emitting diode lighting device. ADVANTAGE - The graphene matrix composite (C2) has: a thickness of 10 nm to 200 mu m; a density of 1.5-2 g/cm3, a porosity of 5-20%, or both; a thermal conductivity of 600-1750 W/mK; an electrical conductivity of 2000-10000 S/cm; a tensile strength of 40-200 MPa; a rockwell surface hardness of 60-100; graphene crystals of 100 mu to 1 cm in size (all claimed). DETAILED DESCRIPTION - Graphene matrix composite (C1), comprises: a single crystal graphene matrix material, containing closely packed and chemically bonded graphene planes having an inter-graphene plane spacing of 0.335-0.4 nm and an oxygen content of 0.001-10 wt.%; a carbon or graphite filler phase comprising carbon or graphite fiber, carbon or graphite nanofiber, carbon nanotube, carbon nanorod, mesophase carbon particle, mesocarbon microbead, 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 and/or activated carbon particle, where the filler phase is covalently bonded to the matrix material, and the filler phase has a weight fraction of 0.01-99% based on the total composite weight. INDEPENDENT CLAIMS are also included for: (1) a graphene matrix composite (C2), comprising a polycrystalline graphene matrix material having incomplete grain boundaries, containing closely packed and chemically bonded graphene planes, carbon or graphite filler phase; (2) producing (P1) graphene matrix composite comprising the polycrystalline graphene matrix material, comprising preparing a graphene oxide gel having graphene oxide molecules dispersed in a fluid medium, mixing a carbon or graphite filler phase into the graphene oxide gel to form a slurry, dispensing the slurry onto a surface of a supporting substrate or a cavity of a molding tool to form a wet composite precursor, partially or completely removing the fluid medium from the wet composite precursor to form a composite precursor and heat treating the composite precursor at 100-3000 degrees C to form the graphene matrix composite; and (3) producing (P2) graphene composite monolith or sheet comprising the polycrystalline graphene matrix, comprising preparing a graphene oxide gel having graphene oxide molecules dispersed in a fluid medium, impregnating the graphene oxide gel into a porous mat, web, perform, paper or fabric to form a wet composite precursor, dispensing the wet composite precursor onto a surface of a supporting substrate or a cavity of a molding tool to form a shaped wet composite precursor, partially or completely removing the fluid medium from the shaped wet composite precursor to form a composite precursor and heat treating the composite precursor at 100-3000 degrees C to form the graphene composite monolith or sheet, where the mat, web, perform, paper or fabric occupies a weight fraction of 1-99% after heat treatment.