Novel thin-film reverse osmosis membrane with MXene Ti3C2Tx embedded in polyamide to enhance the water flux, anti-fouling and chlorine resistance for water desalination

Abstract

The development of high performance reverse osmosis (RO) membranes still remains a big challenge due to not only the trade-off between water flux and salt rejection, but also their easy fouling and chlorine attacking. In this paper, a novel thin-film nanocomposite RO membrane with two-dimensional MXene Ti3C2Tx embedded in the polyamide (PA) layer was fabricated by in-situ interfacial polymerization with m-phenylenediamine aqueous solution and trimesoyl chloride. Due to the outstanding diffusion regulating effect of Ti3C2Tx in accordance with the Fick's first law, the water permeability was elevated to a maximum value of 2.53 L m−2 h−1 bar−1 at a high NaCl salt rejection of 98.5%. Simultaneously, the enhanced anti-fouling, and chlorine resistance of the as-obtained PA-Ti3C2Tx membrane were also obtained, outperforming the pristine PA and other related RO membranes in literature. Especially after a chlorine-resistance test at 10000 ppm h, a high salt rejection of 97.1% for the PA-Ti3C2Tx membrane was still retained. Based on the microstructural observation and mechanism analysis, such an improvement in chlorine resistance was mainly ascribed to the interaction between surface functional groups of Ti3C2Tx nanosheets with active chlorine, which effectively protected the PA matrix from being chlorine attacked. This work illustrates successfully a very new use of Ti3C2Tx to improve the comprehensive performance for water desalination membranes for practical applications.