Mixed Matrix Membranes Based on Sodium Alginate Modified with Microwaved-Synthesized Chromium Oxide for Enhanced Pervaporation Dehydration of Isopropanol

Abstract This study reports the development of mixed matrix membranes (MMMs) from sodium alginate (SA) modified with microwaved-synthesized Cr2O3 microparticles for enhanced pervaporation dehydration of isopropanol. The optimal chromium oxide content within the SA matrix was identified, and cross-linking with CaCl2 of membrane based on optimal SA/Cr2O3 (5%) composite was performed to improve performance in separating dilute mixtures. Comprehensive characterization using FTIR, NMR, XPS, XRD, SEM, AFM, thermogravimetric analysis, and contact angle measurements was carried out to study the modifier and to confirm membrane structural and surface modifications. Incorporation of the optimal 5 wt % Cr2O3 concentration into SA membrane, combined with cross-linking, resulted in a twofold increase in permeation flux (0.22–0.47 kg/(m2 h)) while maintaining high selectivity (7326-2331 separation factor, constant 99.9 wt % water in the permeate) compared to the pristine SA membrane in pervaporation dehydration of isopropanol with up to 30 wt % water. The membrane’s performance is further highlighted by a PSI value of 1586–1087 kg/(m2 h), indicating its high effectiveness. These findings demonstrate the potential of the developed membranes for efficient dehydration processes.