▎ 摘　　要

NOVELTY - Graphene oxide filler comprises surface modifier which is zwitterionic substances; and graphene oxide combined with the surface modifier. USE - The graphene oxide filler is useful in polymer composite membrane (claimed). ADVANTAGE - The graphene oxide filler has excellent hydrophilicity due to ionic bond with water including zwitterionic material, has excellent contamination resistance and dispersibility in base polymer, so that even small amount of addition can improve properties of membrane, improves physical properties of membrane, provides membrane having long life and excellent separation performance, and stability against external pressure, and is simple and efficient as the graphene oxide can be modified through single process. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) producing graphene oxide filler comprising (a) mixing graphene oxide and surface modifier which is zwitterionic material, and (b) bonding the surface modifier to the surface or edge of the graphene oxide; and (2) polymer composite membrane comprising 100 pts. wt. base polymer, and 0.01-4 pts. wt. graphene oxide filler.