Analysis of Sorption and Pervaporative Dehydration of Isopropyl Alcohol Through <scp> TiO ₂ </scp> and Clay Filled Terpolymer Composite Membranes

ABSTRACT This study aimed to develop a highly water‐selective membrane using low‐cost monomers and inorganic fillers. Accordingly, TiO 2 and sodium montmorillonite (Na‐MMT) clay filler incorporated terpolymer composites of poly(acrylonitrile‐co‐vinyl pyrrolidone‐co‐acrylic acid) were synthesized by in situ incorporation of different weight% of fillers during the emulsion polymerization of acrylonitrile (AN), 1‐vinyl‐2‐pyrrolidinone (VP), and acrylic acid (AA) at different AN:VP:AA molar ratios. Several membranes were prepared from these composites by the solvent casting method. The polymer and the membranes were characterized. The sorption of 75–100 wt% isopropyl alcohol (IPA)‐water mixtures in membranes was analyzed using Flory‐Huggins thermodynamic interaction parameters, while the solvent clustering in the membranes was evaluated by the modified Engaged Species Induced Clustering model. The solvent diffusion through the membranes was analyzed using the total solution volume fraction (TSVF) model. The CP5 membrane, prepared with an AN:VP:AA molar ratio of 5:1:1, exhibited the best results for thickness‐normalized flux ( J T ) and separation factor for water ( α PV ) by pervaporation. The CP5 membrane filled with 1 wt% Na‐MMT clay and 0.5 wt% TiO 2 showed the highest J T / α PV of 8.55 kg/m 2 h μm/645.8 for the azeotropic IPA‐water (87.5/12.5) binary mixture, with a good fit of permeation data to the TSVF model.