Preparation of modified membrane of polyvinylidene fluoride (PVDF) and evaluation of anti-fouling features and high capability in water/oil emulsion separation

The conventional Polyvinylidene Fluoride (PVDF) membrane was modified by polymerization Reversible addition-fragmentation chain-transfer (RAFT) with copolymer (PEGMA-co-BVIm-Br) on the upper bulk. This copolymer was obtained from the synthesis of (BVIm-Br) 3-butyl-1-vinyl-1-H-imidazole-3-ium bromide and the vinyl imidazole (VI) monomer N-vinyl imidazole (a hydrophilic monomer) and 1-bromobutane (C4H9Br). The analysis of such as ATR-FTIR, the magnetic resonance of H-NMR nuclei, zeta potential, Water Contact Angle (WCA), and Scanning Electron Microscopy (SEM) confirmed the presence of copolymer on the surface of the modified membrane. The bonding of this copolymer on the membrane surface reduced the WCA of the membrane water (from 89.5 +/- 1.96 to 33.8 +/- 1.55). The raw PVDF membrane (M1) and modified membrane (with total ratio-P(PEGMA-co-BVIm-Br) copolymer 2.5 % (M2), 5 % (M3), 10 % (M4), 20 % (M5), and 40% (M6) to (raw PVDF membrane) membrane showed appropriate hydrophilic nature and excellent separation of oil droplets from water/oil emulsions in the simulated effluent on the surface. This operation was performed for a comprehensive study on the determined parameters and by filtration with simulated petrochemical industry effluent (containing water/oil emulsion). Therefore, the recovery efficiencies of water flux, flow flux, oil recovery amount, as well as total fouling of M6 membrane were reported 96.14 +/- 0.99 and 428 +/- 2.6 L/ (m2 h), 96.1 +/- 1.3%, and 17.18 +/- 0.37%, respectively. This study aimed to prepare a copolymer-modified membrane that can show high performance in cleaning and resistance to various fouling, such as Rt, Rr, and Rir at the specified temperature, after long-term emulsion separation. (c) 2021 Published by Elsevier B.V. on behalf of Taiwan Institute of Chemical Engineers.

Automated summary

The study modified the conventional PVDF membrane using a hydrophilic copolymer synthesized through RAFT polymerization, resulting in excellent performance in separating oil droplets from water/oil emulsions. The presence of the copolymer on the surface of the modified membrane significantly reduced the water contact angle, leading to improved separation efficiency.