2D laminar maleic acid-crosslinked MXene membrane with tunable nanochannels for efficient and stable pervaporation desalination

Two-dimensional (2D) laminar materials have shown great promise in membrane applications. Herein, a maleic acid covalent-bridged MXene (MXMA) membrane supported on microporous nylon substrate is fabricated via a facile vacuum-assisted filtration synthesis and studied for pervaporation desalination. The adjacent MXene nanosheets are strongly fixed by the covalent bonding formed by the esterification reaction between the carboxyl groups in maleic acid and hydroxyl groups in MXene surface. In this way, the crosslinked MXMA membrane features enlarged and structurally well-packed nanochannels as well as large slip length, leading to outstanding desalination performance with improved water permeance and nearly complete salt rejection. Moreover, the swelling resistance of MXMA membrane is dramatically enhanced due to the strong chemical bond between MXene layers, which contributes to the excellent stability.