Enhanced permeability and antifouling properties of polyvinylidene fluoride ultrafiltration membrane with hydrophilic P(AMPS‐co‐MMA) copolymer

In this research, a new amphiphilic random copolymer of 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS) and methyl methacrylate (MMA) (abbreviated as P(AMPS‐co‐MMA)) was synthesized by solution free radical copolymerization method, and was introduced into hydrophobic polyvinylidene fluoride (PVDF) membrane via nonsolvent induced phase separation (NIPS) process without adding pore‐forming agent to enhance the permeability and antifouling properties of PVDF ultrafiltration membrane. The FT‐NMR spectroscopy confirmed the chemical structure of P(AMPS‐co‐MMA) and copolymerization of AMPS and MMA, the effects of P(AMPS‐co‐MMA) on membrane surface chemical compositions, morphology, roughness, charge, hydrophilicity, permeability and antifouling properties were characterized in‐detail. The results indicate that the PVDF/P(AMPS‐co‐MMA) composite membranes demonstrated excellent permeability, improved antifouling property and long‐term stability due to the optimized membrane microstructure, stronger hydrophilicity and endowed negative charge. The PVDF composite membrane blended with 1.5 wt% P(AMPS‐co‐MMA) showed the best membrane performances, the pure water flux was 286.5 L·m−2·h−1 while the BSA rejection was as high as 98%, and the flux recovery ratio (FRR) and reversible fouling ratio to the total fouling ratio (Rr/Rt) reached 94.8% and 87% respectively, which outpaced ever reported and commercial PVDF membranes. Therefore, P(AMPS‐co‐MMA) copolymer was expected to be a potential excellent pore‐forming material in fabricating high‐performance membranes.