Thin film composite nanofiltration membranes with polystyrene sodium sulfonate–polypiperazinetrimesamide semi‐interpenetrating polymer network active layer

Abstract The present work depicts the preparation, characterization, and application of thin film composite nanofiltration (TFCNF) membranes. TFCNF membranes having polyacrylonitrile ultrafiltration support with active layer made of polystyrene sodium sulfonate–polypiperazinetrimesamide semi‐interpenetrating polymer network (semi‐IPN) are prepared. Membranes with semi‐IPN active layer exhibited better hydrophilicity, higher negative zeta potential and surface roughness in comparison with NF membranes having virgin polypiperazinetrimesamide as the active layer. Semi‐IPN membranes exhibited pure water permeability 103 ± 10 LMH at 150 psi pressure and rejection ratio of bivalent to monovalent salts as 2.7, whereas for virgin polypiperazinetrimesamide membrane the values, are 42 ± 5 LMH and 2.1, respectively. The semi‐IPN NF membranes showed better antifouling behavior than the virgin polypiperazinetrimesamide membrane. The flux recovery ratio and total fouling ratio of semi‐IPN NF membrane were observed 97.8 and 3.3% whereas for polypiperazinetrimesamide NF membranes, the values are 90.9 and 10.5%, respectively.