Polysulfone-based membranes for industrial CO₂ capture: Advanced fabrication strategies, performance enhancement, and commercial viability – A review

Polysulfone (PSF) membranes, known for their high thermal stability and tunable gas separation properties, have significant potential for industrial CO₂ capture. They exhibit exceptional thermal resilience (up to 180 °C) and mechanical robustness, both of which are essential for sustainable large-scale applications. This review examines recent advancements in PSF membranes, focusing on fabrication methods, functionalization strategies, and performance optimization. Processing techniques such as non-solvent-induced phase separation (NIPS), electrospinning, and hybrid procedures significantly influence the membrane morphology and the permeability-selectivity trade-off. Functionalization strategies, including the incorporation of amines, ionic liquids (ILs), and MOFs, have improved CO₂ permeabilities by more than an order of magnitude and doubled the selectivities compared to neat PSF membranes, often surpassing the Robeson upper bound and establishing new benchmarks for industrial CO₂ capture applications. Mixed-matrix membranes (MMMs) that incorporate selective fillers exploit the structural resilience of PSF to overcome the limitations of unmodified polymers. However, important challenges remain, including high-pressure plasticization (>35 bar) and nanofiller clustering (>15 wt%), and scalability barriers. Emerging technologies, such as atomic layer deposition, enzyme immobilization, bio-derived precursors, and AI-guided design, are being explored to address these challenges. This review provides insights into the development of PSF membranes from foundational research to implementation in industrial CO₂ separation systems.