MXene Film as an\nInterlayer for Thin-Film Composite\nMembranes with High-Performance Nanofiltration

Abstract

Nanofiltration is seen as a potential technique for desalination\nand purification of drinking water. Improving water permeability without\ncompromising on the high rejection rate in nanofiltration membranes\nis a major challenge. This article describes interfacial polymerization\n(IP) mediated by tannic acid (TA)–MXene interlayer to prepare\nan ultrathin film composite membrane (TFC_i) possessing\nnegative surface charge and optimized water transport channel. Nanofiltration\nprocess and the formation of the polyamide surface layer are both\ndependent on the TA–MXene intermediate layer. It is capable\nof storing amine monomer, decelerating interfacial polymerization,\nand producing a 30-nm-thick polyamide selective layer devoid of defects.\nWith a rejection rate of 96.0% for divalent ions and a permeation\nflux of 22.3 L m^–2 h^–1 bar^–1, the nanofiltration membrane that was acquired exhibits\nexceptional performance and stability in the operation of long-term\nnanofiltration. In contrast to traditional TFC membranes, the TFC_i membrane successfully overcomes the long-standing contradiction\nbetween permeability and selectivity. This study offers a straightforward\nmethod for fabricating TFC membranes that exhibit outstanding performance.