CHE: Molecularly tunable polymer membranes for precise chemical separations

Details

Title: Molecularly tunable polymer membranes for precise chemical separations

Abstract: Highly selective polymer membranes could revolutionize how industrial separations for ions, liquids, and gases are performed due to their inherent energy efficiency. Unfortunately, identifying polymer functional groups that could enable precision separations is hindered by synthetic difficulties of efficiently incorporating diverse chemical moieties into well-controlled polymer structures.

We addressed these challenges by developing a versatile synthetic platform using active ester “click” chemistry to prepare controlled libraries of functionalized membranes for ion separations in aqueous solutions. Hydrogel networks were prepared using active ester co-monomers that can be functionalized after polymerization with a wide array of ligands while maintaining direct control over polymer architecture and functionality. Using this platform, we found that interactions between divalent ions and grafted Lewis-base ligands (e.g., imidazole) increase divalent salt sorption while slowing diffusion, increasing divalent/monovalent ion selectivity. Pulsed-Field Gradient NMR measurements further reveal how microscale water, cation, and anion transport is coupled with membrane hydration and ligand chemistry.

“Click” chemistry thus offers a powerful and versatile tool to enable mechanistic insights into macroscopic and microscopic transport in polymer membranes. Looking forward, my group aims to develop new modular strategies for studying transport mechanisms in next-generation membranes for carbon capture, hydrocarbon purification, and perfluoroalkyl substance (PFAS) remediation.

Bio: Dr. Joshua Moon is an Assistant Professor of Chemical Engineering at UF. Prior to joining UF faculty in 2023, he worked as a postdoctoral researcher at UC Santa Barbara under the guidance of Prof. Craig Hawker and Prof. Rachel Segalman as part of the Center for Materials for Water and Energy Systems (M-WET) in the Materials Science Department and Department of Chemical Engineering. He received his Ph.D. in Chemical Engineering in 2019 from the University of Texas at Austin where he was an NSF Graduate Research Fellow under the advisement of Prof. Benny Freeman and Prof. Donald Paul. His prior research focused on multicomponent gas and vapor transport in glassy and rubbery polymers and macroscopic and molecular scale transport in polymers for ion-selective separations.

Dr. Moon’s research group at UF aims to tackle Grand Challenges in clean water, energy, and sustainability by coupling innovative soft material design for membranes and adsorbents with a fundamental understanding of molecular transport in polymers that is informed by polymer physics and thermodynamics. Current applications for his research span conventional and direct air capture of CO2, selective hydrocarbon separations, environmental remediation of water resources, PFAS capture and removal, and sustainable use of polymer materials.