Surface modification of a commercial thin film composite polyamide reverse osmosis membrane by carbodiimide-induced grafting with poly(ethylene glycol) derivatives

Based on the existing carboxylic acid groups on surface of used commercial thin film composite polyamide reverse osmosis membrane, two kinds of poly(ethylene glycol) derivatives with different chains were grafted by carbodiimide-induced method to improve the antifouling property. The membranes before and after modification were characterized by attenuated total reflectance Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy and static contact angle measurement. Moreover, the water flux, NaCl rejection and fouling experiments were also conducted. The changes of chemical composition and morphology on membrane surfaces indicated the successful grafting of poly(ethylene glycol) derivatives. Compared to unmodified membrane, the modified membranes were more resistant to fouling in protein and cationic surfactant feeding solutions. The method in this study provided a new way for surface modification of commercial polyamide reverse osmosis membranes. (C) 2011 Elsevier B.V. All rights reserved.