▎ 摘　　要

NOVELTY - Preparation of composite heat-conducting film involves stir-mixing aramid fiber and potassium hydroxide in mass ratio of 1:1-1:2 with dimethyl sulfoxide to obtain aramid nanofiber/dimethyl sulfoxide (ANF/DMSO) solution, then adding water to ANF/DMSO solution at volume ratio of 1:1-4:1, stirring, suction filtering, washing and homogenizing to obtain aramid nanofiber aqueous dispersion, mixing 0.005-0.05 part mass carbon nanotube powder, 0.005-0.1 part mass dispersant, 0.005-0.1 part mass stabilizer, and 1 part mass water and dispersing to obtain carbon nanotube dispersion, adding graphene oxide to water, controlling the concentration of graphene oxide to be 0.005-1 %mass, and stirring to obtain graphene dispersion, adding carbon nanotube dispersion to aramid nanofiber aqueous dispersion to obtain modified dispersion liquid, compounding with graphene dispersion, then filtering, drying, and heat-treating to obtain film. USE - Preparation of composite heat-conducting film for preparing heat dissipation component of electronic device (all claimed) such as such as smart phones, tablet computer, LEDs, and TV. ADVANTAGE - The preparation method solves the problem of poor dispersion of carbon nanotube and graphene oxide, and mechanical property of the film by utilizing the interaction between ANF, carbon nanotube and graphene oxide, and provides thin and lightweight heat-conducting film meeting the purpose of miniaturization. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for the composite heat-conducting film, which has excellent performance index such as thermal conductivity at 25°C of 4.5-4.8 W/m.K or more, density of 1.2-1.3 g/cm3, tensile strength of 60-65 MPa and electrical conductivity of 11-12.5 S/cm.