VINSE congratulates Sk Md Ali Zaker Shawon, a Ph.D. candidate in Chemical and Biomolecular Engineering, for the publication of his paper, 鈥淒ecoupling the Influence of Sorption and Diffusion on Membrane Permselectivity in Pervaporation for Ethanol Dehydration,鈥� in the Journal of Membrane Science, and on successfully defending his PhD thesis.
Understanding how membranes separate ethanol鈥搘ater mixtures at the molecular level
Membrane scientists have long known that both sorption and diffusion shape pervaporation performance, but the relative contribution of each mechanism has remained unclear for ethanol dehydration. Shawon鈥檚 study resolves this gap by independently quantifying sorption behavior and transport kinetics across a full range of ethanol鈥搘ater compositions using crosslinked polyvinyl alcohol (PVA) membranes. This approach makes it possible to pinpoint how swelling, water affinity, and polymer free volume each govern separation performance under different feed conditions.
- Sorption selectivity peaks at 70% ethanol, driven by the interplay between membrane swelling and water affinity.
- Diffusion selectivity becomes dominant at high ethanol concentrations, where reduced swelling tightens the polymer matrix and strongly favors the transport of smaller water molecules.
- At 95% ethanol鈥攃onditions most relevant for industrial dehydration鈥攃rosslinked PVA membranes achieve permselectivity exceeding 4500, driven primarily by diffusion selectivity.
A new framework for designing high-performance dehydration membranes
This work provides mechanistic insight into why pervaporation membranes perform exceptionally well near the azeotropic composition and establishes a rational pathway for designing next-generation membranes with enhanced selectivity. The findings also highlight how polymer swelling, free volume, and penetrant鈥損olymer interactions collectively shape separation performance.
Authors and Acknowledgments
The paper is authored by Sk Md Ali Zaker Shawon, Penelope Fries, Longqian Xu, Ruoyu Wang, G. Kane Jennings, and Shihong Lin. The authors acknowledge support from the National Science Foundation (Award #2119575) and the 91吃瓜网 Institute of Nanoscale Science and Engineering (VINSE) for access to characterization tools and technical support.
Read article here in the