Ionic-strength-sensitive polyethersulfone membrane with improved anti-fouling property modified by zwitterionic polymer via in situ cross-linked polymerization

A new method to prepare ionic-strength-sensitive membrane with improved anti-fouling property and blood compatibility is developed via in situ cross-linked polymerization of sulfobetaine methacrylate (SBMA) in polyethersulfone (PES) solution and a liquid–liquid phase separation technique. The modified membrane is characterized by attenuated total reflectance-Fourier transform infrared spectra (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), 1 H NMR measurements, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and water contact angle (WCA) measurement. The membrane with high PSBMA content shows obvious ionic-strength-sensitive property and ionic-strength reversibility, which are expressed by the fluxes of salt solutions. Meanwhile, with the increase of the PSBMA content in the membrane, the anti-fouling property and blood compatibility are considerably improved.