Constructing zwitterionic surface of nanofiltration membrane for high flux and antifouling performance

Antifouling performance of nanofiltration membrane is critical in applications like water treatment. In this study, surface zwitterionization was conducted by 1, 3-propanesultone ring-opening directly on the nanofiltration membrane prepared by interfacial polymerization of 3,3'-diamino-N-methyldipropylamine and 1, 3, 5 benzenetricarboxylic chloride. The zwitterionic structures improve the hydrophilicity of nanofiltration membrane, thus increase the water permeability and antifouling performance. The zwitterionic membrane have a 72 L m(-2) h(-1) water flux at the optimize condition, which was about 2.4 times that of the pristine membrane without zwitterionization, and with a 89% rejection of MgCl2. Meanwhile, the zwitterionic membrane will have better antifouling performance to protein and polysaccharose. The flux recovery ratio of bovine serum albumin, sodium alginate and lysozyme were all above 95%. The prepared zwitterionic membrane presents prominent high water flux and fouling-resistance performance, indicating it's promising application potential in organic wastewater treatment.