Enhancing separation and long-term performance of reverse osmosis desalination through the incorporation of 15-crown-5 in thin-film composite membranes with Li+ and Na+ augmentation

Thin-film composite (TFC) membranes have been intensively studied for the purpose of improving separation performance. Different additives have been attempted during the interfacial polymerization. In this study, 15-Crown-5 (CE15) was employed as the additive to produce TFC membranes for reverse osmosis. The influences of CE15 on the membrane surface morphology, chemical composition and separation performance were then investigated. By adjusting the CE15 concentration, the optimal membrane demonstrated a significant enhancement in water permeance, which was 117% higher than that of the original TFC membrane while sustaining a comparable salt rejection. Additionally, the effects of introducing Li+ and Na+ in the fabrication of CE15 membranes were explored and found to enhance the performance and long-term stability. Overall, our results indicate the potential for enhancing the separation performance of TFC membranes through the synergistic combination of CE15 with Li+ and Na+, offering a simple way of modifying membranes to achieve a higher efficiency and durability in water purification and other separation processes.