A comprehensive study on phase inversion behavior of a novel polysulfate membrane for high-performance ultrafiltration applications

Abstract The microorganisms and natural organic matters (NOM) in the water significantly threaten the health of human being, thus, it is an emerging demand for removal of those pollutes via the cost-efficient ultrafiltration technique. Non-solvent induced phase separation (NIPS) is the most frequently employed method for preparing ultrafiltration membrane in industry, however, the intrinsic weaknesses of porous polymeric membranes, e.g. weak mechanical property, foulants adsorption, and low-resistance to acidic/basic conditions, greatly hamper their applications. Thus, novel polymer materials are required to tackle the issues. In this study, we used a novel polymer, polysulfate (PSE) and adopted it for preparing ultrafiltration membrane via NIPS approach. The phase inversion process of the PSE casting membrane was comprehensively studied by choosing different solvents and water as coagulation bath. The top surface (TS) pore size of the resultant membranes was tailored by changing the solvent or tuning the polymer concentration, reaching as small as 10 nm with a porosity of 82.6 ± 0.9%. The ultrafiltration performance of the optimized membrane outperforms most of the polymeric membranes, which shows both high flux of 135.8 ± 10.7 LMH and rejection efficiency of 99.1 ± 0.83% for 100 ppm HA aqueous solution. Furthermore, the prepared membrane also owns antifouling and acid/alkaline-resistance characters, which endow the PSE membrane with great promise in the future industrially ultrafiltration applications.