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

Abstract

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 nonsolventinduced phase-separation method. The PVDF-g-NMA copolymer was characterized by 1 H 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.

Fabricating novel PVDF-g-IBMA copolymer hydrophilic ultrafiltration membrane for treating papermaking wastewater with good antifouling property

“…The C p and C f values were resolved using a Ultraviolet-visible Spectrophotometer (UV-6000, Shanghai Yuanyi Apparatus Co., Ltd, China) in the wavelength of 280 nm. The calibration curve of BSA concentration was consistent with those in previous reports (Tong et al 2020).…”

“…As shown in Figure 8, the surface and cross-sectional morphologies images of the PVDF-g-IBMA copolymer UF membranes were investigated using SEM. The surface morphology characteristics of the PVDF-g-IBMA UF membranes were similar to those of the pure PVDF UF membranes (Tong et al 2020). As the concentration of the membrane casting solution increased, the number of pores on the surface of the formed UF membrane decreased.…”

“…To determine the retention performance of the modified membrane, dextran solution was used as the filter medium by the method reported previously (Tong et al 2020). Molecular weight cutoff (MWCO) is the membrane's retention rate of 90% for dextran solution.…”

“…The antifouling performance of the PVDF homopolymer and PVDF-g-IBMA copolymer membranes was measured using the apparatus at 0.1 MPa for 60 min (Tong et al 2020). The protein fouling potential of the PVDF-g-IBMA UF membranes was evaluated using a BSA solution.…”

“…The water flux and BSA rejection rate of the PVDF-g-THFMA copolymer UF membrane were 293.9 L•m À2 •h À1 and 91.3%, respectively. Tong et al (2020) prepare a novel amphiphilic copolymer of PVDF grafted with 1-Methyl-2-pyrrolidone (NMA, PVDF-g-NMA) using the same method. The water flux and BSA rejection rate of the PVDF-g-NMA copolymer UF membrane were 272.1 L•m À2 •h À1 and 92.6%, respectively.…”