Preparation and characterization of modified polyethersulfone hollow fiber membranes by blending poly (styrene-alt-maleic anhydride)

In this study, pH-sensitive polyethersulfone (PES) hollow fiber membrane was prepared by blending a copolymer of poly (styrene- alt -maleic anhydride) (PSMA). The PSMA alternating copolymer was synthesized by a traditional synthetic route, and was characterized by Fourier transform infrared spectroscopy (FTIR) analysis, nuclear magnetic resonance ( 1 H NMR) and gel permeation chromatography technique (GPC). The PES/PSMA membrane was then transformed to carboxylic PES/PSMA-H carboxylic membrane using sodium hydroxide solution, by which the anhydride groups were transformed to carboxyl groups, and the modified membranes showed excellent pH-sensitivity and pH-reversibility. Furthermore, the alternating copolymer modified PES hollow fiber membranes showed evident hysteresis of water flux, for which it would take several hours to reach the equilibrium state.