Novel PVDF-g-NMA Copolymer for Fabricating the Hydrophilic Ultrafiltration Membrane with Good Antifouling Property

Improving the hydrophilicity of the poly(vinylidene fluoride) (PVDF) ultrafiltration membrane can change its adsorption fouling characteristics. Here, a novel amphiphilic material of PVDF grafted with N-methylolacrylamide (PVDF-g-NMA) was developed via photoinduced Cu(II)-mediated reversible deactivation radical polymerization (RDRP). The PVDF-g-NMA ultrafiltration membrane was prepared by the nonsolvent-induced phase-separation method. The PVDF-g-NMA copolymer was characterized by 1H NMR and Fourier transform infrared spectroscopy. The performance of the PVDF-g-NMA membrane was evaluated by determining the permeation flux, contact angle, roughness, and antifouling tests. The roughness data show that a low content of N-methylolacrylamide can effectively reduce the surface roughness of membranes by 50%, resulting in greater antifouling ability. The prepared ultrafiltration membrane containing 15 wt % PVDF-g-NMA exhibited the best hydrophilicity with an average pure water flux of up to 272.1 L·m–2·h–1, higher than that of the pure PVDF membrane (45.4 L·m–2·h–1). The contact angle of the PVDF-g-NMA ultrafiltration membrane decreased from 85.5 to 67.4°. The bovine serum albumin rejection rate of the PVDF-g-NMA membrane significantly increased from 85.7 to 92.6%, and the pure water flux recovery rate increased from 79.0 to 88.5%. The PVDF-g-NMA ultrafiltration membrane had excellent hydrophilicity and antifouling properties, which would be promising for wastewater treatment.