A facile and viable approach to fabricate polyamide membranes functionalized with graphene oxide nanosheets

Abstract

Recently, graphene oxide (GO) nanosheet modified polyamide reverse osmosis (PA RO) membranes have been widely studied to improve the hydrophilicity and antifouling performance of PA RO membranes. However, a viable strategy for grafting GO nanosheets on the membrane surface remains challenging. In this study, a facile and viable approach to fabricate PA membranes functionalized with GO nanosheets is presented. The strategy is to react the primary amine functional groups of aminated GO (AGO) with the unreacted acid chloride groups of the nascent PA membrane. The successful grafting of AGO nanosheets on a membrane surface was demonstrated by field emission scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The effects of grafted AGO nanosheets on membrane surface properties were evaluated by contact angle goniometer, atomic force microscopy and electrokinetic analyzer. In addition, the AGO nanosheet dipping concentration was optimized by assessing the desalination performance under brackish water desalination conditions. With 0.15 wt% AGO nanosheet dipping concentration, the resulting surface functionalized membrane showed a water flux of 5.62 L per m² per h per bar and a salt rejection of 97.9%. Compared to the control PA membrane, the surface functionalized membrane exhibited 45.2% higher water flux and comparable salt rejection. Moreover, the PA membrane functionalized with GO nanosheets showed better antifouling performance.