Surface modification of seawater reverse osmosis (SWRO) membrane using methyl methacrylate-hydroxy poly(oxyethylene) methacrylate (MMA-HPOEM) comb-polymer and its performance

Abstract

Comb-like amphiphilic copolymer, methyl methacrylate-hydroxy poly(oxyethylene) methacrylate (MMA-HPOEM), was synthesized by free radical polymerization and then applied to a seawater reverse osmosis (SWRO) membrane to introduce hydrophilicity and fouling resistance. The amphiphilic copolymer preparation was verified using nuclear magnetic resonance, and the deposition of the copolymer on the membrane using dip-coating method was confirmed using X-ray photoelectron spectroscopy. The surface charge that resulted from the amphiphilic copolymer application was analyzed using zeta-potential analysis. Cross-flow fouling test studies showed that the MMA-HPOEM coating on the membrane improved the fouling resistance to bovine serum albumin, Escherichia coli, and seawater. Although the initial flux of the modified membrane was lower than that of the virgin membrane due to the additional hydraulic resistance, the rate of flux decline slowed after the modification and compensated for the initial flux decline within several days.