Effect of Solution Viscosity on the Precipitation of PSaMA in Aqueous Phase Separation-Based Membrane Formation

Aqueous phase separation (APS) is a recently developed sustainable alternative to the conventional organic solvent based nonsolvent-induced (NIPS) method prepare polymeric membranes. In APS, polyelectrolytes are precipitated from aqueous solutions through pH or salinity switches. Although APS differs NIPS in polymer and solvents, they share many tuning parameters. this work, we investigate APS-based preparation of membranes poly(styrene-alt-maleic acid) (PSaMA) with focus on acid concentration coagulation bath, additive casting solution. Nanofiltration prepared using significantly lower concentrations acid: 0.3 M HCl compared 2 either acetic phosphoric used previous works. It shown that higher can be prevent defect formation top layer. addition, also strongly affects solution viscosity thus control membrane structure, where macrovoids support structure. The nanofiltration exhibit very low molecular weight cutoff (210 ± 40 dalton), making these relevant for removal contaminants emerging concern. Understanding how parameters described here affect performance essential optimizing towards important application.