▎ 摘　　要

NOVELTY - Producing highly oriented graphene film comprises: (a) preparing pristine graphene dispersion having oxygen-free pristine graphene sheets dispersed in fluid medium; (b) dispensing and depositing pristine graphene dispersion onto surface of supporting substrate to form layer of pristine graphene; (c) partially or completely removing fluid medium from layer of pristine graphene to form layer of dried pristine graphene; (d) slicing layer of dried pristine graphene into multiple pieces of dried pristine graphene or repeating steps (b) and (c) to produce multiple layers of dried pristine graphene, and stacking at least two layers of dried pristine graphene under optional first compressive stress to form mass of multiple layers of dried pristine graphene; and (e) heat-treating the mass of multiple layers of dried pristine graphene at first heat treatment temperature higher than 2000 degrees C under second compressive stress for time to get the film. USE - The process is useful for producing highly oriented graphene film (claimed) which is useful in flexible graphite sheets, dissipation film used in a smart phone, tablet computer, flat-panel TV display, or other microelectronic or communications device. ADVANTAGE - The highly oriented graphene film has a thickness less than 100 mu m, oxygen content less than 0.01% preferably no greater than 0.001%, inter-graphene spacing less than 0.337 nm preferably less than 0.336 nm, thermal conductivity of at least 1,300 W/mK preferably greater than 1600 W/mK, or electrical conductivity no less than 5000 S/cm preferably greater than 10000 S/cm, exhibits a degree of graphitization no less than 90% and/or a mosaic spread value no greater than 0.4, physical density greater than 1.9 g/cm3, a tensile strength greater than 80 MPa, and/or an elastic modulus greater than 60 GPa (claimed). DETAILED DESCRIPTION - Producing highly oriented graphene film comprises: (a) preparing a pristine graphene dispersion having oxygen-free pristine graphene sheets dispersed in a fluid medium; (b) dispensing and depositing the pristine graphene dispersion onto a surface of a supporting substrate to form a layer of pristine graphene, where the dispensing and depositing procedure includes subjecting the pristine graphene dispersion to an orientation-inducing stress; (c) partially or completely removing the fluid medium from the layer of pristine graphene to form a layer of dried pristine graphene; (d) slicing the layer of dried pristine graphene into multiple pieces of dried pristine graphene or repeating steps (b) and (c) to produce multiple layers of dried pristine graphene, and stacking at least two layers of dried pristine graphene under an optional first compressive stress to form a mass of multiple layers of dried pristine graphene; and (e) heat-treating the mass of multiple layers of dried pristine graphene at a first heat treatment temperature higher than 2000 degrees C under a second compressive stress for time to produce the highly oriented graphene film.