A comprehensive review on polymer nanocomposite membranes for desalination and water remediation

The escalating global demand for clean water necessitates the development of advanced membrane technologies capable of addressing complex contamination challenges and increasing the desalination efficiency. Polymeric membranes are commonly used due to their scalability and processability; however, their efficiency is limited by permeability-selectivity trade-offs and fouling. Polymer nanocomposite membranes (PNCMs) provide a promising substitute for the incorporation of functional nanofillers into polymer matrices for improving the separation efficiency. This review focuses on PNCMs for water purification and desalination, highlighting the importance of nanofillers like carbon nanotubes, graphene, and graphene oxide, metal and metal oxide nanoparticles (TiO₂, ZnO, Ag), zeolites, and metal-organic frameworks. The influence of fabrication strategies, including phase inversion, electrospinning, and interfacial polymerization, on membrane structure-property relationships is systematically examined. While PNCMs demonstrate enhanced water permeability, selectivity, antifouling characteristics, and mechanical robustness compared to pristine membranes, their performance remains highly sensitive to nanofiller dispersion, interfacial compatibility, and structural stability. Key challenges, including nanoparticle agglomeration, long-term durability, and scalability constraints, are highlighted. Finally, future perspectives emphasize rational nanofiller design, controlled interface engineering, and scalable manufacturing approaches to enable the development of robust, high-performance membranes for sustainable water treatment.