Preparation and characterization of mixed matrix membranes based on PVC/Al2O3 for the separation of toluene/n-heptane mixtures via pervaporation

This study reports on the preparation and characterization of mixed matrix membranes, prepared by dispersing aluminum oxide (Al2O3) nanoparticles in a polyvinyl chloride (PVC) matrix using tetrahydrofuran (THF) as a solvent via the casting solution method. We characterized the structure and properties of these membranes by XRD, FTIR, TGA, SEM, EDX, swelling test and pervaporation testing. Swelling test of the PVC/Al2O3 mixed matrix membranes showed that the membranes exhibited preferential absorption of toluene, and the swelling rate of the membranes increased from 0.2% to a maximum of 37% in 50 wt% toluene/n-heptane. It was found that the PVC transport properties could be significantly modified by the amount of Al2O3 incorporated. The membranes were also tested for their ability to separate toluene/n-heptane by pervaporation. Among all the membranes prepared, the PVC-5%Al2O3 membrane exhibited the best pervaporation performance, with a normalized flux of 0.68 kg/m2.h and a separation factor of 12.22 for a 50 wt% toluene/n-heptane solution at 59°C, compared to that of pure PVC which has a flux of 0.05 kg/m2.h and a separation factor of 9.7 at 54°C in the same mixture.