▎ 摘　　要

NOVELTY - Preparing graphene-based composite heat-conducting film comprises e.g. heating the coal tar asphalt under an argon atmosphere, grinding and screening the coal tar asphalt after removing the light oil component, ultrasonically processing the coal tar asphalt, centrifuging to remove insoluble matter, dispersing the graphene oxide filter cake in the coal tar asphalt solution, coating the graphene oxide-based composite slurry in the fourth step on the substrate cloth, and obtaining the graphene oxide-based composite film, immersing the graphene oxide-based composite membrane in a reducing agent solution to carry out chemical reduction treatment, drying, subjecting the pre-reduced graphene oxide-based composite film to two-step thermal reduction treatment, heating, naturally cooling it down to room temperature, and carrying out hot pressing treatment to the graphene-based composite foam film to obtain a graphene-based composite heat-conducting film. USE - The method is useful for preparing graphene-based composite heat-conducting film. ADVANTAGE - The method improves the in-plane thermal conductivity and out-of-plane thermal conductivity of the graphene-based composite thermal conductivity film. DETAILED DESCRIPTION - Preparing graphene-based composite heat-conducting film comprises (1) heating the coal tar asphalt with a particle size of ≤ 200 meshes sieve to 360°C at a rate of 5°C/minute under an argon atmosphere, and maintaining the temperature for 2 hours to remove the light oil component, (2) grinding and screening the coal tar asphalt after removing the light oil component in the first step to obtain the coal tar asphalt with a particle size ≤ 500 meshes sieve, (3) ultrasonically processing the coal tar asphalt whose particle size is ≤ 500 objects at 50kHz in the solvent for 24 hours, and centrifuging at 2000 revolutions/minute for 10 minutes to remove insoluble matter to obtain a coal tar asphalt solution, (4) dispersing the graphene oxide filter cake in the coal tar asphalt solution to obtain the graphene oxide-based composite slurry, (5) coating the graphene oxide-based composite slurry on the substrate cloth, and drying to obtain the graphene oxide-based composite film, (6) immersing the graphene oxide-based composite membrane in a reducing agent solution at 40-100°C for 0.5-24 hours to carry out chemical reduction treatment, and drying to obtain a pre-reduced graphene oxide-based composite film, (7) subjecting the pre-reduced graphene oxide-based composite film to two-step thermal reduction treatment, heating from room temperature to 1000-1400 °C at a rate of 0.5-3 °C/minute under an argon atmosphere for 0.5-2 hours, and then cooling it down to room temperature naturally, heating from room temperature to 2600-3000°C at a rate of 1-5°C/min under an argon atmosphere for 0.5-2 hours, and then naturally cool to room temperature to obtain a graphene-based composite foam film, and (8) carrying out hot pressing treatment to the graphene-based composite foam film to obtain a graphene-based composite heat-conducting film.