Sustainable Aqueous Phase Separation membranes prepared through mild pH shift induced polyelectrolyte complexation of PSS and PEI

Abstract pH shift induced Aqueous phase separation (APS) is a novel and more sustainable water-based approach to create microfiltration, ultrafiltration, nanofiltration membranes. APS allows for control over membrane pore size structure in ways analogous traditional non-solvent (NIPS). Unfortunately, existing approaches require extreme shifts (from 14 1) obtain successful membranes, limiting their applicability large scale production. Here we demonstrate that with tunable sizes ranging from ~80 nm dense type, can be prepared using mild (pH 12 4) based on the complexation of poly(styrene sulfonate) (PSS) branched polyethyleneimine (PEI) acetate buffer coagulation baths. The molecular weight PEI, concentration value solution, glutaraldehyde cross-linking agent were systematically varied optimize fabrication conditions. It was found tight membranes having cut-off ~200 g mol?1 excellent salt (97% MgCl2) micropollutant retentions (~96%) could alongside ultra/microfiltration type an average ~60 nm. These results indicate under conditions properties.