▎ 摘　　要

NOVELTY - Preparation of composite modified film involves (S2) mixing tris(hydroxymethyl)aminomethane hydrochloride buffer solution having pH of 6-9, with dopamine hydrochloride and 1,3-diaminoguanidine hydrochloride to obtain a reaction solution, soaking polyvinylidene fluoride film in the reaction solution, and modifying by oxidation deposition, and (S2) immersing polydopamine-guanidine-based antibacterial agent composite modified film in the aminated graphene oxide solution and grafting. USE - Preparation of composite modified film used in water treatment (all claimed) including sewage treatment, drinking water treatment and industrial wastewater from petrochemical and biomedical industries. ADVANTAGE - The composite modified film has excellent resistance to organic pollution and antibacterial performance, and has flatter membrane surface, stronger mechanical strength, and improved anti-pollution ability.