Covalently assembling multi-dimensional carbon-based nanoclay composites via ionic liquid linkers into PVA membrane for molecular separation

The application of membrane-based separation technology in purifying azeotropic solutions plays a crucial role in minimizing energy consumption during reactive distillation. The strategic integration of multi-dimensional structural composites within mixed matrix membranes (MMMs), characterized by a robust framework and efficient molecular transport channels, poses challenges but demonstrates significant potential for advancing the development of high-performance membrane fabrication. Herein, we proposed a novel strategy to covalently assemble halloysite nanotubes (HNTs) and graphene oxide (GO) using ionic liquids (ILs) as linkers. When incorporated into the polyvinyl alcohol (PVA) matrix, the ILs@HNTs@GO (IHGO) composites exhibit excellent interfacial compatibility, and ILs also enhanced the composite's selective transfer ability to water molecules. The optimal separation performance for pervaporation dehydration from a ternary solution was respectively 2.57 (selectivity) and 1.74 (permeability) times higher than those of the pristine PVA membrane. The structural stability of the MMMs and their separation mechanism has been comprehensively validated by adjusting the content of GO in IHGO composites and conducting simulations. This study holds significant theoretical and practical implications for organic compounds purification, while simultaneously paving new avenues for the fabrication of structurally robust and high-performance MMMs with optimal filler effectiveness.