▎ 摘　　要

NOVELTY - A graphene oxide composite nano-filter film preparing method involves preparing graphene oxide water solution to expandable graphite as raw material, followed by adding concentrated sulfuric acid, potassium permanganate and hydrogen peroxide solution to obtain graphene oxide water solution, which is subjected to modified Hummmer's process, followed by preparing graphene oxide cross-linking solution by adding graphene oxide water solution with cross linker to obtain mixture. The pH of the mixture is adjusted by using alkaline solution to prepare graphene oxide crosslinking solution. USE - Method for preparing graphene oxide composite nano-filter film. ADVANTAGE - The method enables preparing graphene oxide composite nano-filter film with high hydrophilicity, high flux, industrial application prospect and improved desalting effect. DETAILED DESCRIPTION - A graphene oxide composite nano-filter film preparing method involves preparing graphene oxide water solution to expandable graphite as raw material, followed by adding concentrated sulfuric acid, potassium permanganate and hydrogen peroxide solution to obtain graphene oxide water solution. The graphene oxide water solution is subjected to modified Hummmer's process, followed by preparing graphene oxide cross-linking solution by adding graphene oxide water solution with cross linker to obtain mixture. The pH of the mixture is adjusted by using alkaline solution to prepare graphene oxide crosslinking solution, followed by preparing graphene oxide composite nanofiltration membrane by using a polymer membrane as base membrane, surface coating process on the base film by using aqueous solution of carboxymethyl chitosan coating layer. The resultant film is dipped in crosslinked layer of graphene oxide solution to obtain finished product.