MXene (Ti3T2CX)-reinforced thin-film polyamide nanofiltration membrane for short-chain perfluorinated compounds removal

Per- and polyfluoroalkyl substances (PFAS) are a class of ‘forever chemicals’ that have become a global concern owing to their innate chemical stability on humans and water resources. The separation of PFAS from water resources via membrane technologies are facing huge challenge. High permeance and rejection membrane are required for PFAS. To achieve this goal, herein, we propose an MXene-reinforced interfacial polymerization of negatively charged polyamide (PA) membranes for high rejection of short-chain PFAS. The morphologies and chemical properties were systematically investigated for the fabricated membrane. Attributed to the hydrophilic of MXene, the permeance of MXene-PA membranes increased without sacrificing rejection. Density functional theory (DFT) calculations and various experiments elucidated in detail the underlying mechanism of the interactions between the membrane and PFAS. The enhanced electrostatic interaction and hydrogen bonding leaded to increased PFAS rejection and permeance. Therefore, the MXene-regulated PA membrane effectively solved the trade-off between the selectivity and permeability. This work shows that MXene-regulated interfacial polymerization techniques can be used to tailor the effectiveness of PA nanofiltration membranes to overcome the trade-off phenomenon and pave the way for solving the crisis of short-chain PFAS.