▎ 摘　　要

NOVELTY - Preparing polyimide-graphene composite gel involves dissolving diamine in a polar solvent and dispersing to ultrasonic state to obtain diamine solution. The obtained diamine solution is dispersed the graphene oxide and stable dibasic amine-oxidized graphene dispersion. The molar ratio of dianhydride to diamine is 1.2:1-1: 1, and mass ratio of graphene to dibasic anhydride and diamine is 0.2:100-2:100. The dianhydride is added into the dispersion of diamine-oxide graphene and stirred in an ice-water bath to obtain polyamic acid-graphene solution. USE - Method for preparing polyimide-graphene composite gel (claimed). ADVANTAGE - The method enables to prepare polyimide-graphene composite gel, which has excellent heat resistance, and is processed in simple and easy manner. DETAILED DESCRIPTION - Preparing polyimide-graphene composite gel involves dissolving diamine in a polar solvent and dispersing to ultrasonic state to obtain diamine solution. The obtained diamine solution is dispersed the graphene oxide and stable dibasic amine-oxidized graphene dispersion. The molar ratio of dianhydride to diamine is 1.2:1-1: 1, and mass ratio of graphene to dibasic anhydride and diamine is 0.2:100-2:100. The dianhydride is added into the dispersion of diamine-oxide graphene and stirred in an ice-water bath to obtain polyamic acid-graphene solution. The polyamic acid-graphene solution is precipitated in ice water, freezing in refrigerator and freeze-drying through freeze-drying machine to obtain polyamic acid-graphene oxide filament. The polyamic acid-enriched graphene filament is dispersed in the deionized water, and the polyamic acid-oxidized graphene dispersion by ultrasonic and stirring. The polyamic acid-oxidized graphene dispersion is allowed to stand for a period of time, and the polyamic acid-graphene gel is obtained by the sol-gel process. The polyamic acid-graphene gel is frozen in solid nitrogen in liquid nitrogen and then freeze-dried in a freeze dryer to obtain polyamic acid-graphene composite gel. The polyimide-graphene composite airgel is prepared by subjecting the polyamic acid-graphene gas gel to hot an amination in a nitrogen atmosphere.