Comparative study of PS and PES and their sulfonated forms in antifouling behavior and rejection efficiency

In this study, novel hybrid ultrafiltration (UF) membranes were developed using polyethersulfone (PES), poly- sulfone (PS), and their sulfonated counterparts (SPES and SPS) to enhance water flux and antifouling properties. FTIR and XRD analyses validated the successful incorporation of sulfonate groups and structural changes, while SEM images revealed more porous and uniform membrane structures. Thermogravimetric analysis (TGA) showed enhanced thermal stability for the sulfonated membranes. Mechanical property evaluations demonstrated that the sulfonated membranes maintained good tensile strength and flexibility. Water uptake and porosity mea- surements indicated increased hydrophilicity and porosity for SPES and SPS membranes compared to their pristine forms. The pure water flux of SPES (130 L/m2⋅h) is significantly higher compared to PES (110 L/m2⋅h). The sulfonated membranes (SPS and SPES) exhibit significantly enhanced antifouling properties, as demon- strated by the improved flux recovery ratios (FRR) for SA, BSA, and HA compared to their non-sulfonated counterparts (PS and PES), reaching up to 75 % for SPES. The rejection performance for BSA, HA, and SA so- lutions showed that SPES membranes achieved 95 %, 90 %, and 92 % rejection rates, respectively, compared to 80 %, 75 %, and 70 % for PS membranes. Fouling resistance tests using BSA, HA, and SA solutions showed that SPES and SPS membranes had significantly higher flux and lower fouling tendencies.