MXene-regulation polyamide membrane featuring with bubble-like nodule for efficient dye/salt separation and antifouling performance

Removing salt from dye/salt mixtures using nanofiltration (NF) membranes needs to be improved to ensure high permeability, high selectivity, and antifouling performance. In this study, we used an interfacial polymerization (IP) technique to create a novel thin-film nanocomposite NF membrane by introducing two-dimensional MXene Ti3C2Tx into the polyamide (PA) layer. Enhanced IP reaction rate facilitated the overflow of residual solvent from the fresh PA layer's edge due to the MXene-mediated IP strategy, resulting considerable bubble-like nodules on the membrane surface. The unique nanostructure of PA effective layer could be tuned by controlling the MXene concentration in aqueous phase solution, which finally promoted the obtained membranes with superb permselectivity. In this way, the water permeability was elevated to a maximum value of 45.12 L m(-1) h(-1), nearly 1.58-fold compared to the PA-pristine membrane. Moreover, the Ti3C2Tx/NF membrane exhibited a superior dye/monovalent salt separation coefficient of 820, outperforming the pristine PA membrane and other NF membranes in the literature. Additionally, the MXene-assisted IP strategy designed an effective dye anti-fouling hydration layer, which played a crucial role in fouling resistance. This work illustrates a novel use of Ti3C2Tx to successfully regulate high-performance TFN PA membranes for potential application in dye/salt separation.

Automated summary

This study focuses on improving the performance of nanofiltration (NF) membranes for removing salt from dye/salt mixtures. By introducing two-dimensional MXene Ti3C2Tx into the polyamide (PA) layer using interfacial polymerization (IP) technique, a novel thin-film nanocomposite NF membrane was created. The addition of MXene enhanced the reaction rate and resulted in a unique nanostructure of the PA layer, leading to membranes with high permeability and selectivity. The MXene-assisted IP strategy also improved the membrane's antifouling performance.