Tuning d-spacing of graphene oxide nanofiltration membrane for effective dye/salt separation

Abstract The interlayer spacing (i.e., d -spacing) plays a crucial role in determining the selectivity and permeability of nanofiltration membranes. A high-throughput directional filtration can be achieved by designing controlling -spacing. In this study, -spacing graphene oxide (GO) membrane was tuned fixed to desired value (approximately 0.79 nm) using solution polyethyleneimine (PEI) GO at PEI/GO mass ratio 15:1. resultant deposited on polyacrylonitrile (PAN) substrate form robust composite (a PEI/GO@PAN membrane). as-prepared exhibited an ultrahigh flux 117.8 L·m −2 ·h −1 , rejection values for Direct Red 80 (DR80) Na 2 SO 4 reached 99.7% < 1.7%, respectively; these are desirable dye/salt separation. excellent performance, had longer lifespan reusability because its reinforced nature. This work suggested that tuning with PEI would effective strategy achieve anticipated functions Graphical abstract