Fabrication of ultra-thin polyelectrolyte/carbon nanotube membrane by spray-assisted layer-by-layer technique: characterization and its anti-protein fouling properties for water treatment

Abstract

Polyethersulfone (PES) membranes are extensively used as ultrafiltration (UF) membrane owing to their superior thermal, mechanical, and chemical stability. However, commercial PES membranes are more prone to fouling, which contributes to severe decline in permeate flux with operation time. To improve the commercial PES UF membrane anti-protein fouling properties, negatively charged functionalized multi-walled carbon nanotube (f-MWCNTs), blended poly(sodium 4-styrenesulfonate) (PSS), and positively charged poly(diallyldimethylammonium chloride) (PDDA) were deposited on 20kDa PES substrate through spray-assisted layer-by-layer (LbL) technique. Further cross-flow UF tests were conducted with bovine serum albumin (BSA) as model protein. The total flux loss results show that surface-modified PES membranes are less susceptible to protein fouling by one-hour BSA filtration. Moreover, flux recovery ratios show that 20-min de-ionized (DI) water flushing is effective to restore water flux of the prepared membrane without aggressive chemical cleaning. Based on the experimental results, the excellent anti-fouling properties render the prepared membranes suitable for recycling utilization.