Fouling of nanofiltration membranes based on polyelectrolyte multilayers: The effect of a zwitterionic final layer

In this work, we investigate the effect of membrane surface chemistry on fouling in water treatment for polyelectrolyte multilayer based nanofiltration (NF) membranes. The approach allows us to prepare three membranes with same active separation layer, apart from a difference chemistry: nearly uncharged crosslinked Poly(allylamine hydrochloride) (PAH), strongly negative poly(sodium 4-styrene sulfonate) PSS and zwitterionic poly(2-methacryloyloxyethyl phosphorylcholine-co-acrylic acid) (PMPC-co-AA). Initially, study foulant adsorption different surfaces (on model interfaces), demonstrate how top layer affects subsequent five foulants (Humic Acids, Alginates, Silica Nanoparticles, negatively positively charged Proteins). Subsequently, our hollow fiber NF identical surfaces. Our results show that PAH generally fouls more than surface. While BSA adsorbs better PSS, probably due charge regulation. Overall, was mainly driven by electrostatic acid-base interactions, which led, both terminated membranes, flux decline changes selectivity. contrast, through filtration experiments carried out synthetic real water, bio-inspired phosphatidylcholine exhibits excellent resistance thus stable performance during filtration.