Effective construction of anti-fouling zwitterion-functionalized ceramic membranes for separation of oil-in-water emulsion based on PDA/PEI co-deposition

Ceramic membranes have been widely used in oil-water separation owing to their characteristics of high flux, excellent chemical stability, strong hydrophilicity, and good fouling resistance. To further enhance their anti-fouling performance, a co-deposition reaction was employed for the surface modification of the ceramic membranes in this study. Polyethyleneimine and dopamine were used to introduce tertiary amine groups on the surface of the ceramic membranes, and sodium 2-bromoethanesulfonate was used for the quaternization reaction with tertiary amine groups. According to the water contact angle measurements, the ceramic membrane functionalized via zwitterionic modification exhibited better hydrophilicity and thus could absorb water droplets faster than pristine ceramic membranes. Consequently, the zwitterion-functionalized ceramic membrane achieved double the permeance (40 L m −2 h −1 bar -‍1 ) compared to the original ceramic membrane (20 L m −2 h −1 bar -‍1 ) during the separation of the oil-in-water emulsion, suggesting good anti-fouling performance. • The zwitterionic ceramic membrane was fabricated by a two-step grafting method. • Polydopamine enhances the modification of zwitterions on ceramic membrane. • The surface hydrophilicity was enhanced after the zwitterionic modification. • The prepared membrane shows an antifouling property in O/W emulsion separation.