Hydrophilic coating of membrane by UV-induced radical and cationic curing of photosensitive resins: Lower shrinkage, smoother surface and better anti-fouling performance

• Published in: Progress in organic coatings Vol. 195; p. 108666
• Main Authors: Wen, Shaobin, Xu, Yao, Fan, Liyuan, Peng, Bin, Zhang, Jingyu, Zhang, Qiang, Pang, Yulian, Deng, Yufei, Zou, Yingquan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2024
• Subjects: Antifouling performance; Cationic photopolymerization; Hydrophilic coating; Photosensitive resin; Radical photopolymerization; Antifouling performance; Hydrophilic coating; Cationic photopolymerization; Radical photopolymerization; Photosensitive resin
• ISSN: 0300-9440; 1873-331X
• DOI: 10.1016/j.porgcoat.2024.108666

Hydrophilic coating is frequently used to enhance the anti-fouling performance of membrane. However, traditional strategies often suffer from defects of cumbersome steps, high energy consumption, and unstable coating. Herein, radical and cationic photopolymerization are used for hydrophilic coating of membranes. Two photosensitive resins were first synthesized either by direct radical copolymerization of 3-ethyl-3-(methacryloyloxy) methyloxetane and 2-hydroxyethyl acrylate (Poly(HEA-EMO)) or through post-polymerization modification of poly(2-hydroxyethyl acrylate) with vinyl groups (Poly(HEA-MA)). Subsequently, hydrophilic coating was conducted on the membrane surface by UV-induced curing of different photosensitive resins, either through radical photopolymerization of vinyl-functional Poly(HEA-MA) or cationic photopolymerization of Poly(EMO-HEA) with pendent oxetane groups. The modified membranes showed enhanced hydrophilicity and underwater oleophobicity than the original membrane. Moreover, the coating (PAN / HEA(C5)) by cationic photopolymerization exhibited lower shrinkage, smoother surface, and more excellent antifouling performance than that by radical photopolymerization. After bovine albumin fouling-cleaning cycles, the flux recovery rate (FRR) of the original membrane was only 68.6 %, while the FRR of PAN / HEA(C5) was as high as 98.0 %. Furthermore, it showed superior long-term operational stability, proving the stability of the coating formed by cationic photopolymerization. [Display omitted] •Photosensitive resins were synthesized by radical photopolymerization and post-photopolymerization modification.•Photosensitive resins have multiple pendent oxetane or vinyl functional groups.•Hydrophilic coatings on PAN membrane were formed by radical photopolymerization and cationic photopolymerization.•The coating formed by cationic photopolymerization had lower shrinkage, smoother surface, and better antifouling performance.