Surface hydrophilic modification of polyethersulfone membranes by surface-initiated ATRP with enhanced blood compatibility.

Surface-initiated atom transfer radical polymerization (SI-ATRP) was used to tailor the functionality of polyethersulfone (PES) membranes. A two-step method including nitration reaction and amination reaction was used to synthesize aminated polyethersulfone (PES-NH2) for the preparation of PES/PES-NH2 membranes. Covalently tethered hydrophilic polymer brushes of poly(N-vinylpyrrolidone) (PVP) were prepared via SI-ATRP at low temperature in an aqueous solvent. Attenuated total reflection-Fourier transform infrared (ATR-FTIR), scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS), and water contact angle were used to characterize the modified membranes surfaces. The PVP-grafted PES membranes showed lower protein adsorption and suppressed platelet adhesion compared with the pristine PES membrane. Moreover, the activated partial thromboplastin time (APTT) for the PVP-grafted PES membranes was increased. These results indicated that the surface hydrophilic modification by grafting PVP brushes provided practical application for the PES membranes with good blood compatibility.