ChE Seminar Series: Versatile soft materials for membrane separations for clean water and energy

Details

Joshua D. Moon, Ph.D.
Postdoctoral Scholar at The University of California, Santa Barbara

“Versatile soft materials for membrane separations for
clean water and energy”

Abstract: Opportunities are numerous for advanced soft materials to tackle Grand Challenges for Engineering through supplying clean energy, addressing climate change, promoting sustainability, and ensuring resource and water security. Gas- and solvent-selective polymer membranes are attractive tools for carbon capture and energy efficient purification of hydrogen and hydrocarbon resources. Chemically-patterned polymer membranes and adsorbents also offer promise for fit-for-purpose treatment of wastewater and produced water from hydraulic fracturing, potentially enabling removal of recalcitrant contaminants from water and recovery of valuable minerals such as lithium.

Addressing water, energy, and environmental separation challenges with polymer membranes requires marriage of innovative material design with a fundamental understanding of the interplay between molecular diffusion, thermodynamics, and polymer physics. Major challenges still face membrane separations, such as their intrinsic tradeoff between permeability and selectivity as well as synthetic challenges associated with incorporating solute-selective functional groups into polymer membranes and absorbents. This presentation will discuss two new synthetic strategies for preparing gas separation and water purification membranes with tailorable molecular architectures and functionality to address these challenges.

The first part of this talk will focus on a method of improving membrane H2/CO2 separation performance through synergistic polymer blending and thermally-activated post-functionalization, which could strengthen the competitiveness of membrane technology for emerging separation applications such as pre-combustion carbon capture. The unique matrix-droplet microstructure of these membranes affords gas permeabilities and selectivities that surpass the conventional “upper bound” for H2/CO2 separation performance while also yielding mechanical flexibility and toughness.

The second part will discuss development of a versatile synthetic platform that is capable of generating a library of functional hydrogel membranes using active ester chemistry. These membranes can be easily substituted with a wide variety of ligands to promote targeted separation of water, ions, and organic dyes. This network platform further enables direct control over key membrane properties such as water uptake and functional group grafting density, which allows us to systematically investigate membrane structure-property relationships through both macroscopic and NMR-based diffusion techniques.

Bio: Joshua Moon is currently a postdoctoral scholar at the University of California, Santa Barbara and is co-advised by Prof. Craig Hawker in the Department of Materials and Prof. Rachel Segalman in the Department of Chemical Engineering. As part of the Center for Materials for Water and Energy Systems (M-WET) EFRC, his research has been focused on developing synthetic platforms for versatile, ligand-functionalized membranes and elucidating fundamentals of molecular-scale and macroscopic water and ion transport in polymer membranes. Applications for this work include fit-for-purpose water treatment and selective ion removal for resource recovery. He received his Ph.D. in Chemical Engineering from The University of Texas at Austin under the mentorship of Prof. Benny Freeman and Prof. Donald Paul in 2019 and previously received his B.S. in Chemical Engineering from The University of Alabama in 2014. His doctorate work focused on the impact of humidity and polymer blending on molecular transport in polybenzimidazole gas separation membranes with applications in carbon capture and clean hydrogen production.