Development of novel NH4Y zeolite-filled chitosan membranes for the dehydration of water-isopropanol mixture using pervaporation

NH4Y zeolite-filled chitosan membranes were developed for the separation of water-isopropanol mixture using pervaporation process. The NH4Y zeolite-filled chitosan membranes were prepared using a solution technique with the variation of NH4Y zeolite loading (0, 0.1, 0.2, 0.3, 0.4, 0.5 wt.%). The membranes morphologies were studied using Scanning Electron Microscopy (SEM) and the membranes mechanical strength were tested using the parameter of tensile strength and percent strain at maximum. The effects of NH4Y zeolite loading on the liquid sorption characteristics and pervaporation performance were also evaluated. The diffusion coefficient of water and isopropanol for the chitosan membranes at different NH4Y zeolite loading is estimated. The presence of NH4Y zeolite in the chitosan membranes caused non-homogeneous dispersion of NH4Y zeolite crystals and membrane swelling due to its hydrophilic properties. However, the presence of NH4Y zeolite was able to improve both tensile strength and percent strain at maximum of chitosan membranes. The presence of NH4Y zeolite also increased the total permeation flux and separation factor simultaneously. The Pervaporation Separation Index shows that 0.2 wt.% of NH4Y zeolite-filled membrane gave the optimum performance in the pervaporation process. The diffusion coefficient estimated proves that the membranes were highly water selective.