ZWitterionic sulfobetaine groups were grafted onto polysulfone (PSU) membrane surface with 2-azidoethyl methacrylate and N,N-diethyl-N-propargyl-N-(3-sulfopropyl) ammonium (DEPAS) via surface-initiated Atom Transfer Radical Polymerization (ATRP) and "click" chemistry in a two-step process. The PSU membranes were fully characterized by attenuated total reflectance Fourier transform infrared spectra (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and static water contact angle (WCA) measurement. Results showed that zwitterionic monomers were efficiently grafted onto PSU surfaces. The water contact angle, bovine serum albumin (BSA) protein adsorption and platelet adhesion were obviously decreased after grafting zwitterionic sulfobetaine groups onto the membrane surface. These indicated that the zwitterionic sulfobetaine modified PSU membranes presented good biocompatibility. This study provides a new approach for surface modification of polysulfone with different functionalities.
