Effect of porous substrate morphology and characteristics on the performance of thin-film composite polyamide reverse osmosis membranes

Water scarcity is an urgent global challenge, driving the development of advanced desalination technologies. Among them, reverse osmosis (RO) membranes-particularly thin-film composite (TFC) polyamide membranes-have emerged as a leading solution for water purification. The performance of TFC membranes is strongly influenced by the properties of their porous substrates, which provide critical support to the selective polyamide layer. This study offers a comprehensive overview of porous substrate engineering in TFC RO membranes, emphasizing fundamental design principles, operational performance, and future directions. Key substrate attributes such as porosity, hydrophilicity, and mechanical strength, and their impact on membrane efficiency-including water flux, salt rejection, and durability-are critically examined. Advanced fabrication techniques, including phase inversion and interfacial polymerization, are discussed with a focus on how substrate characteristics affect the formation of the polyamide rejection layer. Challenges related to fouling resistance, structural stability, and environmental sustainability are also highlighted. Overall, porous substrate engineering holds great promise for the development of next-generation TFC membranes, offering pathways toward more efficient, durable, and sustainable water treatment solutions.