▎ 摘　　要

NOVELTY - A dispersion of isolated graphene sheets is produced by (a) exposing coal or coke powder and liquid medium to supercritical fluid at a 1st temperature and a 1st pressure for a 1st period of time in a pressure vessel and (b) rapidly depressurizing supercritical fluid at a fluid release rate sufficient for effecting exfoliation and separation of coal or coke powder to produce isolated graphene sheets, where coal or coke powder is selected from petroleum coke, coal-derived coke, mesophase coke, synthetic coke, leonardite, anthracite, lignite coal, bituminous coal, and/or natural coal mineral powder. USE - Production of dispersion of isolated graphene sheets for composite material (claimed). Can also be used for graphene-containing ink composition. ADVANTAGE - The supercritical fluids can penetrate spaces between graphene-like or graphene oxide-like planes in a coal or coke structure; and through variations in temperature and pressure, the supercritical fluids can exfoliate and separate these planes to obtain isolated graphene sheets. The supercritical fluids are also capable of severing and extracting graphene domains or individual graphene sheets from a complex graphene domain-amorphous structure commonly found in a coal or coke material. Supercritical fluid state also enables the resulting graphene sheets to be well-dispersed in a very liquid medium, where the coke/coal powder is dispersed, producing a homogeneous suspension. One major advantage of this approach is that exfoliation, separation, and dispersion of graphene sheets are achieved in a single step.