Polymeric Membranes for Advanced Separation and Sensing: Materials and Mechanisms for Emerging Applications-A Review

Polymeric membranes have emerged as pivotal tools in advanced separation technologies due to their tunable properties, processability, and cost-effectiveness. This review critically evaluates recent advancements in membrane technologies, with a focus on their applications in water treatment, energy systems, and biomedical fields. Notable developments include nanocomposite membranes with enhanced performance, such as PSF/MXene membranes achieving > 95% rejection of bovine serum albumin (BSA) and water permeabilities exceeding 400 L·m⁻²·h⁻¹·bar⁻¹. Electrospun nanofibrous membranes demonstrated flux values ranging from 6898 to 18,614 L·m⁻²·h⁻¹ for oily wastewater filtration. Functionalized UF membranes incorporating TiO₂-HNTs and Ag-PDA-HNTs achieved > 98% BSA rejection and superior antifouling capabilities. Smart membranes, such as PNIPAM-modified systems, showed reversible wettability changes and temperature-responsive permeability. Additionally, 3D-printed and TIPS-fabricated membranes showcased improved selectivity and mechanical robustness. Environmentally friendly fabrication using green solvents, such as Rhodiasolv PolarClean®, enabled the production of high-performance membranes with rejection rates of over 85% for NaCl and over 93% for MgCl₂. Despite these advancements, challenges like fouling, high fabrication costs, and the permeability-selectivity trade-off persist. Strategies such as nanomaterial integration, stimuli-responsive design, and circular economy-aligned biodegradable polymers are analyzed as pathways for next-generation sustainable membranes.