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Fabrication of anti‐fouling thin‐film composite reverse osmosis membrane via constructing heterogeneous wettability surface
Author(s) -
Chen Dandan,
Gao Feng,
Liu Tianyu,
Kang Jian,
Xu Ruizhang,
Cao Ya,
Xiang Ming
Publication year - 2021
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.51256
Subject(s) - membrane , fouling , chemical engineering , contact angle , wetting , materials science , surface energy , reverse osmosis , membrane fouling , grafting , zeta potential , chromatography , polymer chemistry , chemistry , composite material , nanotechnology , polymer , nanoparticle , biochemistry , engineering
Anti‐fouling properties are tightly related to the surface properties of reverse osmosis (RO) membranes. In our study, fluorinated polyethyleneimine (FPEI) was synthesized by introducing perfluoroalkyl groups into a hydrophilic polyethyleneimine (PEI) matrix, and the heterogeneous wettability surface with hydrophilic and low‐surface‐energy properties was constructed by grafting FPEI on membrane surface via the carbodiimide‐induced method. Verified by the result analysis of SEM, AFM, and zeta potentials measurements, the fluorinated RO membrane surface presented denser, smoother, and reduced negative charge. The surface free energy of RO membrane surface after grafting FPEI decreased from 45.5 to 38.7 mJ/m 2 . By using bovine serum albumin (BSA), humic acid (HA), and dodecyltrimethyl ammonium bromide (DTAB) as model foulants, the fluorinated RO membrane exhibits optimal fouling resistance and fouling release properties compared to pristine membrane and membrane modified by surface grafting hydrophilic PEI. Especially, the high recovery ratio (99%) and low total flux decline ratio (17.2%) were acquired during the filtration of BSA solution. These results manifested that the construction of a heterogeneous wettability surface can further improve the anti‐fouling properties of RO membranes compared to a pure hydrophilic surface, and the corresponding anti‐fouling mechanism was put forward.