PVC-based mixed-matrix membranes based on IL@AC/NH₂-MIL-101 nanocomposites for improved CO₂ separation performance

Mixed matrix membranes (MMMs), an important class of organic-inorganic nanocomposite membranes, were developed to overcome some of the limitations of purely polymeric membranes. In this study to improve the separation performance of polyvinyl chloride (PVC) membranes, mixed matrix membranes (MMMs) were prepared from incorporating choline prolinate based ionic liquid (IL) in a the coke/metal-organic framework (MOF) (NH₂-MIL-101(Cr)) as a filler in polyvinyl chloride (PVC), which can be viewed as a potential solution to the trade-off problem with polymeric membranes because of the combination of the processing versatility of polymers and the high gas separation capability. Coke/MOF/PVC and IL@AC/MOF/PVC MMMs with different filler loadings of 5, 10, and 15 wt% were prepared using solution casting method and characterized using Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) with Energy-Dispersive X-ray Spectroscopy (EDX) analyses, and Brunauer-Emmett-Teller (BET) surface area test. The porous structure of MMMs nanocomposites causes to which coke/MOF composite effectively accelerate gas diffusion in the PVC matrix. The permeability date was measured at 288.15, 298.15, 308.15 and 318.15 K and pressure up to 4 bar for CO₂ and N₂. According to the outcome, the addition of the IL([Cho][Pro]) filler, the permeability of the AC/MOF/PVC MMMs is increased compared to the pure PVC membrane. The MMMs have the highest gas separation efficiency and performance above Robson's Upper Bound from 2008.