▎ 摘　　要

NOVELTY - Graphene oxide titanium dioxide-dopamine polyetherimide (PEI) nanofiltration membrane comprises an organic ultrafiltration membrane support and a functional layer, where the preparation method of the functional layer involves ultrasonically mixing a graphene oxide solution and a titanium dioxide-dopamine aqueous solution, filtering on the surface of the organic ultrafiltration membrane support body to form a membrane, and filtering the PEI aqueous solution on the membrane to crosslink the membrane layer to obtain the functional layer, the concentration of the graphene oxide aqueous solution is 0.2-0.5 mg/l, the concentration of the titanium dioxide-dopamine aqueous solution is 0.2-0.5 mg/l, the mol ratio of titanium dioxide and dopamine is (0.8-1.2):(0.8-1.2), the mass ratio of the graphene oxide aqueous solution and the titanium dioxide-dopamine aqueous solution is 2:(1-2), and the concentration of the PEI aqueous solution is 1-5 wt.%. USE - As graphene oxide titanium dioxide-dopamine PEI nanofiltration membrane. ADVANTAGE - The graphene oxide titanium dioxide-dopamine PEI nanofiltration membrane has pure water flux of 90LHM and high retention of 50 g/l methylene blue. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for preparing the graphene oxide titanium dioxide-dopamine PEI nanofiltration membrane, which involves (i) preparing graphene oxide aqueous solution with the modified Hummers method, (ii) dripping reverse osmosis (RO) water to the alcohol solution of titanium organic salt, adding dopamine, debonding with nitric acid or hydrochloric acid, and stirring at 58-61℃ for 2.5-3.5 hours to obtain a titanium dioxide-dopamine aqueous solution with pH of 3-5, and (iii) ultrasonically uniformly mixing the graphene oxide aqueous solution and the titanium dioxide-dopamine aqueous solution, performing suction filtration on the organic ultrafiltration membrane support body to form a film, subjecting the membrane to upper suction filtration with a PEI aqueous solution to crosslink the membrane layer to form the functional layer, and drying to obtain the graphene oxide titanium dioxide-dopamine PEI nanofiltration membrane.