Zwitterionic analog structured ultrafiltration membranes for high permeate flux and improved anti-fouling performance

Fouling resistant zwitterionic analog ultrafiltration polymer membranes are fabricated from the composite mixture of virgin polysulfone (PSf), chloromethylated polysulfone (CMPSf), and oxidized nano-carbon black (ONCB) using phase inversion process. The chemical characterization of the membranes is performed by 1H NMR, FT-IR and Raman spectroscopy. Thermal gravimetric analysis and scanning electron microscopy are used to determine thermal behavior and morphology of membranes, respectively. Furthermore, surface contact angles, water uptake, and zeta potential of the membranes ensured the hydrophilicity, charges and surface properties of the membranes. The results confirmed the successful fabrication of porous, hydrophilic, and zwitterionic analog ultrafiltration composite membranes. The control and composite membranes are then thoroughly investigated for antifouling properties using BSA as standard foulant. The M4 membrane fabricated from a composite of PSf with CMPSf/ONCB exhibited the highest water flux of 320 L m(-2) h(-1) and 87% BSA rejection. The zwitterion analog membrane also exhibited the lowest irreversible fouling and highest flux recovery ratio among all tested membranes, thus considered as a potential candidate as antifouling membrane. Moreover, the present strategy also offered facile route for the preparation of membranes comprising zwitterion features and excellent antifouling properties.