| Two-dimensional transition metal carbon（nitrogen）compound MXene（Ti3C2Tx）has been widely concerned in the field of membrane separation due to its hydrophilicity and adjustable layer spacing.However,laminar flow MXene membrane is easy to peel from the substrate.Therefore,selecting suitable substrate material and increasing the adhesion between MXene membrane and substrate material are the key to its industrial application.In this paper,α-Al2O3 ceramic tube with large hole was used as the carrier,modified byα-Al2O3 particles and Si O2-Zr O2 sol.MXene membrane was prepared by self-crosslinking reaction of Ti3C2Tx nanoparticle,and MXene membrane was modified by polyvinyl alcohol（PVA）.The dehydration performance of isopropyl alcohol by pervaporation of MXene membrane under different operating conditions was investigated.A swelling equilibrium model was established to analyze the dissolution and diffusion mechanism of isopropyl alcohol and water in mixed matrix films.The conclusion is as follows:（1）The surface of the large holeα-Al2O3 carrier tube is optimized.The large hole defects on the carrier surface can be filled byα-Al2O3 particles of different sizes.The Si O2-Zr O2 intermediate layer obtained by hot dipping and rubbing method helps to further smooth the carrier and reduce the surface roughness of the particle layer.（2）The layered structure formed by MXene nanosheets is conducive to blocking large-diameter isopropyl alcohol molecules from passing through the interlaminar pore.When the loading capacity of MXene nanosheets is 1.97 mg/cm2,MXene membrane exhibits high dehydration performance for 90%isopropyl alcohol/water solution at 55℃,and the moisture content of the permeable side is 95.51%.The flux can reach 485.13g/（m2·h）.（3）The hydrophilic groups（-OH-and-O-）on the surface of Ti3C2Tx nanosheets interact with the-Oh on the PVA molecular chain,which improves the hydrophilicity of MXene/PVA mixed matrix films.When the temperature of the raw material liquid was35℃,MXene/PVA-3.0 mixed matrix membrane showed the best pervaporization performance for 90%isopropyl alcohol/water solution,with the measured water content of 99.62%,the separation factor of 2359.42 and the flux of 281.31 g/（m2·h）.（4）The swelling degree of MXene/PVA mixed matrix film was tested,and the swelling degree was stable below 9.07%.The interaction parameter between water and MXene/PVA mixed matrix membrane is smaller than that between isopropyl alcohol and membrane,so water is preferentially adsorbed and dissolved in MXene/PVA membrane.The swelling equilibrium model was established,and it was found that with the increase of isopropyl alcohol concentration in solution,the concentration of water in the film gradually decreased,and the concentration of isopropyl alcohol in the film first increased and then stabilized. |
