Plasma Graft Polymerization and Surface-Initiated Atom Transfer Radical Polymerization: Characteristics of Low-Fouling Membranes Obtained by Surface Modification with Poly(2-methoxyethyl Acrylate)

Abstract

This study investigated the characteristics of membranes modified by grafting poly(2-methoxyethyl acrylate) (PMEA) onto their surfaces and pore walls via plasma graft polymerization (PGP) and surface-initiated atom transfer radical polymerization (SI-ATRP) to render the membrane surfaces fouling-free. The grafting of PMEA was successfully achieved using both methods. Although no remarkable differences were observed in the modified membranes through structural analyses such as FT-IR and FE-SEM, pure water permeability was higher in the membranes modified by SI-ATRP than in those modified by PGP, particularly at the same grafting amount. This was probably because the length of the grafted PMEA was shorter with a higher PMEA density per surface area when SI-ATRP was employed for the modification with PMEA, compared to those obtained when PGP was used. The modified membranes exhibited excellent low-fouling properties against bovine serum albumin (BSA), regardless of the modification method used. In addition, it was demonstrated that the low-fouling properties resulted from the suppression of BSA adsorption by the grafted PMEA. Finally, no flux decline was demonstrated through a 10 h filtration test of raw water for water supply with the modified membranes, which clearly indicated the effective fouling suppression performance of the modified membranes.