Polymeric membranes for sustainable gas separation: A comprehensive review with challenges, innovations and future perspectives

Pursuing advanced gas separation technologies is pivotal for alleviating global warming, controlling industrial emissions, and facilitating the efficient recovery and purification of gases for both industrial processes and societal requirements. Amid growing concerns over the intensification of greenhouse gas concentrations and the attendant ramifications for global climate systems, polymeric membranes have gained prominence in this domain owing to their intrinsic scalability, energy efficiency, and chemical versatility. This review critically assesses the state-of-the-art in polymeric membrane-based gas separation, focusing on the evolution of membrane materials and the role of molecular-level design in optimizing separation performance. Emphasis is placed on recent advances in polymer science that have enabled significant improvements in gas selectivity, permeability, and operational robustness. Persistent challenges are comprehensively analysed, including the permeability-selectivity trade-off, physical aging, plasticization, and long-term stability. The review further delves into the advent of hybrid membranes, which synergistically incorporate inorganic nanomaterials into polymer matrices to overcome these limitations. Future prospects are discussed in the context of emerging applications such as carbon capture and hydrogen purification, where tailored membrane functionalities and novel fabrication strategies will be critical. The importance of multidisciplinary endeavour is underscored in propelling the next generation of sustainable membrane technologies for high-efficiency gas separations.