▎ 摘　　要

NOVELTY - Thermally conductive graphene-polymer material composite film comprises a multilayer composite film with thermal conductivity anisotropy and thermally driven three-level shape memory characteristics, where the composite film is made of 20-40 wt.% graphene, 30-40 wt.% nanocellulose, and 30-40 wt.% thermoplastic polymer material. USE - As thermally conductive graphene-polymer material composite film. ADVANTAGE - The thermally conductive graphene-polymer material composite film has excellent flexibility, lateral thermal conductivity, low vertical thermal conductivity, high thermal conductivity anisotropy and thermally driven three-level shape memory performance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing the thermally conductive graphene-polymer material composite film, comprising (a) adding graphene to a dispersant, stirring for 0.5-1 hour, and ultrasonically processing for 5-10 minutes to prepare a graphene dispersion with a concentration of 1-3 mg/ml, (b) adding nanocellulose to a dispersant, stirring for 0.5-1 hour, and ultrasonically processing for 5-10 minutes to prepare a nanocellulose dispersion with a concentration of 1-3 mg/ml, (c) adding the thermoplastic polymer material to a dispersant, stirring for 0.5-1 hour, and ultrasonically processing for 5-10 minutes to prepare a thermoplastic polymer material dispersion with a concentration of 1-3 mg/ml, (d) mixing the graphene dispersion liquid obtained in step (a) and the thermoplastic polymer material dispersion liquid obtained in step (c) according to the set weight ratio, stirring for 0.5-1 hour, and ultrasonically processing for 5-10 minutes to obtain a graphene-polymer material mixed solution with a concentration of 5-10 mg/ml, (e) mixing the nanocellulose dispersion liquid obtained in step (b) and the polymer material dispersion liquid obtained in step (c) according to the set weight ratio, stirring for 0.5-1 hour, and ultrasonically processing for 5-10 minutes to obtain a nanocellulose-polymer material mixed solution with a concentration of 5-10 mg/ml, (f) adding the graphene-polymer material mixed solution and the nanocellulose-polymer material mixed solution to a vacuum drying oven, and leaving it in a vacuum environment at room temperature for 0.5-1 hour to remove the gas present in the mixed solution, and (g) pouring the set amount of graphene-polymer material mixture in a mold and placing it in an oven at 40-50 degrees C, drying for 6-10 hours, and pouring the set amount of nanocellulose-polymer material mixture into a mold, placing it in an oven at 40-50 degrees C and drying it for 6-10 hours to prepare a single-layer thermal conductive graphene-polymer material composite film, and (h) repeating the step (g) multiple times, and stacking the single layers together to obtain a multi-layer anisotropic thermally conductive graphene-polymer material composite film with thermally driven three-level shape memory properties.