▎ 摘　　要

NOVELTY - Preparing graphene involves adding graphene oxide to anhydrous toluene, ultrasonically dispersing under the protection of inert gas, adding silane coupling agent, performing reflux reaction to obtain silane coupling agent modified graphene oxide, filtering, washing with anhydrous toluene for three times and drying to obtain the silane coupling agent modified ultrasonically dispersed graphene oxide. The obtained coupling agent modified ultrasonically dispersed graphene oxide is dispersed into deionized water, initiator and N-vinyl pyrrolidone are added, ultrasonic dispersed and stirred. USE - Method for preparing graphene (claimed). ADVANTAGE - The method enables to prepare graphene which is stable, and has biological application prospect and high concentration of the dispersion liquid. DETAILED DESCRIPTION - Preparing graphene involves adding graphene oxide to anhydrous toluene, ultrasonically dispersing under the protection of inert gas, adding silane coupling agent, performing reflux reaction to obtain silane coupling agent modified graphene oxide, filtering, washing with anhydrous toluene for three times and drying to obtain the silane coupling agent modified ultrasonically dispersed graphene oxide. The obtained coupling agent modified ultrasonically dispersed graphene oxide is dispersed into deionized water, initiator and N-vinyl pyrrolidone are added, ultrasonic dispersed and stirred at 70-80 degrees C under the protection of inert atmosphere. The polyethylene glycol allyl ether is added to the obtained dispersed solution, continuously reacted for certain period of time and heated to perform reflux reaction to obtain vinyl pyrrolidone polyethylene glycol allyl ether copolymer as dispersing agent of silane coupling agent-modified graphene oxide dispersion liquid. The pH of the obtained modified graphene oxide dispersion liquid is adjusted to alkalescence by adding the gallic acid and tannic acid, The solution is stirred to dissolve under the protection of inert gas and reacted at 40-90 degrees C. When the reaction is finished, the product is filtered with nylon microporous filtering film and washed for three times with deionized water to remove excess of unbound gallic and tannic acid and unreacted comonomer, and the obtained product is dried at room temperature to obtain graphene.