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 ( R r /R t ) 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.