Preparation of polymer-based membranes and development ofseparation properties

This study presents the synthesis, characterization, and performance evaluation of nanocomposite thin-film composite (TFC) membranes incorporating ZnO/h-BN-based hybrid fillers for enhanced reverse osmosis (RO) desalination. Three types of nanohybrids -ZnO/h-BN, ZnO/GO-h-BN, and ZnO/h-BN-IL- were prepared via hydrothermal and exfoliation-assisted methods, then embedded into polyamide membranes through interfacial polymerization. The structural, morphological, and surface properties of the nanoparticles and membranes were characterized using XRD, FTIR, TGA, DLS, SEM, BET, and contact angle analyses. Among the tested formulations, ZnO/h-BN demonstrated the most balanced performance, achieving a pure water flux of 48.5 L·m⁻²·h⁻¹ and Na₂SO₄ rejection up to 98.5% at an optimal filler loading of 0.015–0.025 wt%. The incorporation of hydroxyl-functionalized nanohybrids enhanced membrane hydrophilicity, surface charge, and porosity, thereby improving water transport and ion rejection simultaneously. ZnO/GO-h-BN yielded higher flux with high salt rejection, while ZnO/h-BN-IL exhibited comparably salt selectivity with superior high flux. All nanocomposite membranes displayed significantly improved antifouling behavior, achieving over 96% rejection of bovine serum albumin (BSA). The results confirm a synergistic interaction between ZnO and h-BN components, facilitating both electrostatic exclusion and nanochannel-driven water transport. Statistical analysis (ANOVA) validated the significant influence of nanofiller type and concentration on performance metrics. This work highlights the potential of ZnO-h-BN hybrid nanostructures in developing next-generation high-performance RO membranes for energy-efficient desalination applications.