▎ 摘　　要

NOVELTY - Peeling graphene comprises mixing graphite powder, bio-based graphene dispersant and deionized water evenly, and peeling off mechanically to obtain graphene dispersion. The bio-based graphene dispersant is polytannic acid polyurethane. USE - The method is useful for peeling graphene useful in preparing graphene flexible film (claimed) is useful in electronic device, preferably mobile phone, personal digital assistant, portable multimedia player, digital camera, digital camcorder, digital video camera, digital photo frame, portable game machine and portable electronic book. ADVANTAGE - The method: prepares graphene dispersion with high solid content, high stability, high quality and few layers; and prepares the graphene by peeling off the obtained graphene film to obtains graphene flexible film with high thermal conductivity and electrical insulation; and is simple and suitable for industrial production. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing graphene flexible film, comprising (i) mixing boron nitride microspheres, modifier and deionized water, dispersing fully and carrying diazotization reaction to obtain a modified boron nitride microsphere dispersion liquid, where the modifier is a bisamino-containing functional group of compounds; (ii) mixing and dispersing the modified boron nitride microsphere dispersion and graphene dispersion uniformly, adjusting the system to a weak alkaline environment with pH=8-10, carrying out an azo reaction to obtain a self-assembled boron nitride/graphene dispersion; and (iii) blending the boron nitride/graphene dispersion uniformly with thermoplastic polyurethane and forming a film.