Modification of Nanofiltration Membranes by Surface-Initiated Atom Transfer Radical Polymerization for Produced Water Filtration

Poly(N-isopropylacrylamide) and poly(N-isopropylacrylamide-block-ethylene glycol methacrylate) were grafted from commercial polyamide thin-film composite nanofiltration membranes using surface-initiated atom transfer radical polymerization. The results from Fourier-transform infrared spectroscopy confirmed the successful grafting of both polymers from the membrane surfaces. Contact angle measurements were done to illustrate the temperature responsive wettability of the modified membrane surfaces. Modified membranes were used in flux measurements of wastewater produced during coal bed methane gas exploration. The degree of fouling of the original and the modified membranes was examined by pure water flux recovery measurements after produced water filtration and a temperature-controlled water rinse.