Mixed matrix chitosan membranes modified with MIL-125 for enhanced sustainable pervaporation

Developing sustainable, biobased membranes for pervaporation is essential to advancing environmentally friendly separation technologies aligned with industrial needs. This study reports the development and comprehensive characterization of pervaporation mixed matrix membranes (MMM) based on chitosan (CS) first modified with a synthesized Ti-based metal-organic framework (MOF)-MIL-125. Key focus was placed on evaluating how MIL-125 concentration and chemical cross-linking with trimesoyl chloride influence membrane structure, physicochemical properties, and performance for isopropanol dehydration. Additionally, supported membranes with a thin, selective CS/MIL-125(15%) layer deposited onto porous substrate were fabricated to assess their potential for applications. Characterization techniques-including FTIR, NMR, SEM, AFM, X-ray diffraction, nitrogen adsorption isotherms, thermogravimetric analysis, and contact angle measurements-were employed to analyze membranes and MIL-125. Quantum chemical calculations provided insights into the molecular interactions between membrane components and feed molecules. The optimized cross-linked supported membrane demonstrated notable improvements in dehydration of isopropanol (up to 90 wt.% water), with increased permeation flux and water content in permeate compared to the pristine CS membrane. These findings highlight the potential of the developed membranes for practical pervaporation applications, emphasizing the effective integration of MIL-125 into biobased materials for pervaporation.