▎ 摘　　要

NOVELTY - Graphene/bacterial cellulose composite material with gradient structure comprises graphene and bacterial cellulose, where the ratio of graphene to bacterial cellulose changes in the direction of the thickness of the material. USE - The composite material is useful for preparing biomimetic biomaterials, electromagnetic gradient materials and conductive gradient functional materials. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing graphene/bacterial cellulose composite material with gradient structure comprising (i) preparing culture medium, and placing in a sterilization pot for high temperature autoclaving for 30-60 minutes, (ii) inoculating a strain into the medium under a sterile environment, culturing at 30 degrees C for 1.5-3 days to obtain bacterial cellulose membrane having a thickness of 1-2 mm, and cultivating a base film of graphene/bacterial cellulose as a membrane liquid interface, (iii) mixing the mixed medium with uninoculated medium into different volume ratio of 1:40-2:1, where the graphene dispersion having the content of graphene is 0.5-2 mg/ml, and obtaining the mixed culture of graphene at 0.024-0.67 mg/ml, ultrasonically processing for 15-30 minutes, and (iv) spraying the mixed medium of different concentrations of graphene in the step (iii) in the form of a mist on the base film of the step (ii), and the volume of mixed medium on the unit basement membrane area is 0.02-0.03 ml/cm2, spraying for 6-100 times, where the concentration of graphene in the mixed medium changing from low to high according to the order of spraying, after each spraying, the mixed medium on the surface of the membrane is consuming, and then performing the next spraying, finally forming a graphene/bacterial cellulose composite film having a thickness of 1-30 mm, washing and lyophilizing.