Hybrid membranes of polyphenylsulfone/functionalized MXene nanosheets for the pervaporation dehydration of acetone and isopropyl alcohol

Abstract

The resistance of pervaporation (PV) dehydration membranes to organic solvents is of great importance. Polyphenylsulfone (PPSU) is known to resist most organic media; however, its acetone dehydration performance has not been evaluated yet. In the present study, MXene hydrophilic nanosheets with hydroxyl functional groups were synthesized and then incorporated in the PPSU membrane to prepare the PPSU/MXene PV membrane for the first time. The prepared membranes were used in the dehydration of acetone/water and isopropyl alcohol (IPA)/water. By comparing the attenuated total reflectance Fourier transform infrared spectroscopy spectra of the pure membrane and the nanocomposite membrane, the incorporation of hydroxyl functional groups into PPSU via MXene loading was confirmed. MXene improved the hydrophilicity and tensile properties of the membrane. The separation factor in acetone dehydration dropped with MXene incorporation up to 1 wt% and then increased with further MXene loading; however, it stayed almost unchanged in IPA dehydration with adding 0.5, 1, and 1.5 wt% MXene to the membrane. Incorporating 1 wt% MXene, the pervaporation separation index (PSI) was improved by 5.8 times in acetone dehydration and 9.7 times in IPA dehydration. The PPSU/1 wt% MXene membrane provided a remarkably higher separation factor (261 vs. 136) and PSI (99 vs. 58 kg/m2h) in acetone dehydration than in IPA dehydration; however, total flux was slightly lower in acetone dehydration (0.38 vs. 0.43 kg/m2h). This study implies that PPSU/MXene is a promising membrane material for the PV dehydration of organics. Highlights MXene hydrophilic nanosheets were synthesized. The synthesized MXene was loaded into the polyphenylsulfone membrane. PPSU/MXene membranes were used in pervaporation dehydration. MXene improved the hydrophilicity and tensile properties of the membrane. PPSU/MXene is a promising membrane material for PV dehydration of organics.