Surface modification of poly(ether sulfone) membrane with a synthesized negatively charged copolymer.

In this study, we provide a new method to modify poly(ether sulfone) (PES) membrane with good biocompatibility, for which diazotized PES (PES-N2+) membrane is covalently coated by a negatively charged copolymer of sodium sulfonated poly(styrene-alt-maleic anhydride) (NaSPS-MA). First, aminated PES (PES-NH2) is synthesized by nitro reduction reaction of nitro-PES (PES-NO2), and then blends with pristine PES to prepare PES/PES-NH2 membrane; then the membrane is treated with NaNO2 aqueous solution at acid condition; after surface diazo reaction, surface positively charged PES/PES-N2+ membrane is prepared. Second, poly(styrene-alt-maleic anhydride) (PS-alt-MA) is synthesized, then sulfonated and treated by sodium hydroxide solution to obtain sodium sulfonated (PS-alt-MA) (NaSPS-MA). Finally, the negatively charged NaSPS-MA copolymer is coated onto the surface positively charged PES/PES-N2+ membrane via electrostatic interaction; after UV-cross-linking, the linkage between the PES-N2+ and NaSPS-MA changes to a...