Thin-film nanocomposite reverse osmosis membranes with enhanced antibacterial resistance by incorporating p-aminophenol-modified graphene oxide

Abstract

Innovative approaches to restraint bacterial adhesion and growth on membranes are significantly needed to avoid membrane performance decaying for biofouling. In this work, a series of thin film nanocomposite (TFN) reverse osmosis (RO) membranes has been prepared by incorporating nano-fillers of p-aminophenol-modified graphene oxide (mGO) into the polyamide skin layer via interfacial polymerization. Our investigations demonstrate that the introduction of mGO nano-fillers into the functional skin layers reduces the hydrophilicities with the water contact angles drop from 69.6° to 48.2° and meanwhile decreases the thickness of functional skin layers from 240 nm to 50 nm, relative to pristine polyamide RO membrane without nano-fillers. As a result, the as-prepared TFN RO membrane at optimized conditions shows a water flux of 23.6 L·m−2·h−1 and a NaCl rejection rate of 99.7%, reflecting a remarkable promotion in water flux (by 24.5%) compared with the pristine RO membrane. In addition, the data statistics of the live/dead fluorescent imaging assay demonstrate that TFN RO membrane with mGO exhibits bacterial killing ratios of 96.78% and 95.26% against E. coli and S. aureus at the additive loading of 0.005 wt%, which are much higher than RO membrane with GO (90.64%; 90.43%) and pristine RO membrane (4.95%; 2.48%). This work demonstrates a facile way to TFN RO membranes with good separation performance and desirable antibacterial capacities.