It is easy to adsorb the pollutants from water owning to the hydrophobicity of the poly(vinylidene fluoride) (PVDF) ultrafiltration (UF) membrane. To improve the hydrophilicity of the PVDF UF membrane, a novel amphiphilic copolymer PVDF-g-poly-N-(3-dimethylaminopropyl)methacrylamide] (PDMAPMA) was developed. The amphiphilic PVDF-g-PDMAPMA was synthesized with PVDF and N-(3-dimethylaminopropyl)methacrylamide (DMAPMA) via free-radical polymerization, and characterized by Fourier transform infrared spectroscopy and 1 H nuclear magnetic resonance. The scanning electron microscopy and energy dispersive X-ray spectroscopy were used to characterize the structure morphologies and elementals of the blend PVDF membranes, respectively. The pure water flux (PWF), molecular weight cutoff, and bovine serum albumin (BSA) solution filtration experiments were tested to evaluate the permeation performance and antifouling properties of the membranes. The experimental results showed that the PWF was 263.1 L m −2 h −1 , BSA rejection rate was 98.1% and flux recovery rate was 95.1% of the prepared blend membrane which had obvious improvement compared with the pristine PVDF membrane (17.3 L m −2 h −1 , 91.0, and 83.8%, respectively). The antibacterial activity test showed the prepared blend membrane had good potency against microorganisms. A novel hydrophilic PVDF membrane with good antibacterial properties was developed and would be promising for wastewater treatment.

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.

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Porous polyphenylsulfone (PPSU) membranes are facilely prepared via the nonsolvent-induced phase separation method. The typical asymmetric structure of such prepared porous membranes can be controlled by optimizing the sulfonation degree of the sulfonated poly(ether ether ketone) to 84.7% in the casting solution. Scanning electron microscopy images show that the porous membrane comprises a thin dense top skin layer, a sublayer structure with distinct long finger-like pores and the large pores in the substructure. The porous PPSU membrane was then used in vanadium flow battery (VFB). The optimized porous membrane yields an admirable performance, including excellent selectivity, chemical stability, and high columbic efficiency. Furthermore, the low cost of porous PPSU membranes indicates the promise of this technology for use in VFB applications.