▎ 摘　　要

NOVELTY - Method for preparing hydrophilic graphene, involves mixing graphene with a surfactant comprising polyethylene glycol type nonionic surfactant, polyetheramine D230 and/or polyetheramine D400, and grinding to obtain hydrophilic graphene, where the solid-liquid ratio of graphene to surfactant is 1g:(10-15) ml. USE - The method is useful for preparing hydrophilic graphene used for preparing cellulose-based graphene flexible conductive nanopaper. ADVANTAGE - The method adopts surfactant to adsorb on the surface of graphene to modify the surface of graphene without oxidizing graphene, ensures the uniform dispersion of graphene, and guarantees the integrity of the graphene structure. The manufactured flexible conductive nanopaper has excellent conductivity and flexibility. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a hydrophilic graphene which is prepared by the above-mentioned method and has a water contact angle of 0-40 degrees ; (2) a cellulose-based graphene flexible conductive nanopaper comprising 5-99 %mass hydrophilic graphene, and 1-95 %mass nanocellulose; and (3) a method for preparing the above-mentioned cellulose-based graphene flexible conductive nanopaper, involving (a) mixing hydrophilic graphene and deionized water, and uniformly stirring to obtain a hydrophilic graphene dispersion, (b) ultrasonically oscillating the hydrophilic graphene dispersion under a frequency of 30-50 kHz until the hydrophilic graphene is dispersed uniformly to obtain the hydrophilic graphene dispersion, (c) mixing the nanocellulose colloid and deionized water, stirring in a high-speed stirrer at a stirring rate of 15000-25000 rpm or probe ultrasound under an ultrasonic frequency of 20-30 kHz until uniformly dispersed to obtain a nanocellulose dispersion, where nanocellulose colloid comprises 1-3 %mass nanocellulose content, (d) mixing the hydrophilic graphene dispersion and the nanocellulose dispersion, and ultrasonically processing for 1-2 hours under the frequency of 30-50 kHz to obtain a uniformly dispersed mixture, and (e) subjecting the dispersed mixture to a membrane filtration to obtain a solid product deposited on the membrane, and drying the membrane from acetone or ethanol to obtain the flexible conductive nanopaper.