More resilient polyester membranes for high-performance reverse osmosis desalination
Yujian Yao, Pingxia Zhang, Fei Sun, W. F. Zhang, Meng Li, Gang Sha, Teng Long, Xianze Wang, Mingxin Huo, Ryan M. DuChanois, Tianchi Cao, Chanhee Boo, Xuan Zhang, Menachem Elimelech
Abstract
Thin-film composite reverse osmosis membranes have remained the gold standard technology for desalination and water purification for nearly half a century. Polyamide films offer excellent water permeability and salt rejection but also suffer from poor chlorine resistance, high fouling propensity, and low boron rejection. We addressed these issues by molecularly designing a polyester thin-film composite reverse osmosis membrane using co-solvent-assisted interfacial polymerization to react 3,5-dihydroxy-4-methylbenzoic acid with trimesoyl chloride. This polyester membrane exhibits substantial water permeability, high rejection for sodium chloride and boron, and complete resistance toward chlorine. The ultrasmooth, low-energy surface of the membrane also prevents fouling and mineral scaling compared with polyamide membranes. These membranes could increasingly challenge polyamide membranes by further optimizing water-salt selectivity, offering a path to considerably reducing pretreatment steps in desalination.