Multifunctional Core-Shell Zwitterionic Nanoparticles to Build Robust, Stable Antifouling Membranes via Magnetic-Controlled Surface Segregation

Novel multifunctional core-shell nanoparticles (Fe₃O₄@PSBMA NPs) with magnetic and zwitterionic properties were first synthesized and efficiently incorporated into the poly(vinylidene fluoride) (PVDF) membranes via magnetically controlled surface segregation toward the better water-energy-food nexus. The combination of zwitterionic polymers poly(sulfobetaine methacrylate) (PSBMA) and Fe₃O₄ particles can improve the compatibility of additives with the PVDF matrix and significantly improve the migration of Fe₃O₄@PSBMA NPs onto membrane surfaces under magnetic fields during nonsolvent-induced phase separations. The modified membrane with surface-enriched multifunctional zwitterionic NPs had an enhanced water flux (168%, â¼630.5 L m^-2 h^-1), excellent fouling resistance (∼93.8%), and increased rejection to bovine serum albumin (94.1%). Most importantly, the PVDF/M-Fe₃O₄@PSBMA membrane had excellent stability under the long-term filtration test for practical water-treatment applications.