▎ 摘　　要

NOVELTY - A zwitterionic functionalized graphene (I), is new. USE - New zwitterionic functionalized graphene used for preparing nanofiltration membrane used in chemical industry, medical application and domestic sewage desalination (all claimed). ADVANTAGE - The zwitterionic functionalized graphene produces nanofiltration membrane with high flux, selectivity and strong inhibitory effect on microorganisms in wastewater. DETAILED DESCRIPTION - A zwitterionic functionalized graphene of formula (I), is new. A = group of formula (s);and n = 10-100. INDEPENDENT CLAIMS are included for the following: (1) synthesis of the zwitterionic functionalized graphene (I); and (2) preparation of amphoteric ionized graphene nanofiltration membrane, which involves ultrasonically-dispersing the amphoteric ionized graphene into a dispersion in an aqueous solution, using flat ultrafiltration membrane as base membrane, vacuum filtering the dispersion liquid to dry, providing certain concentration of glutaraldehyde solution to filtering, taking out the film, and drying in an air oven for certain period of time.