(338c) Combinatorial Approach to Discover Polymeric Membranes for Dehydration of Polar Solvents

Membrane pervaporation is a promising alternative for solvent-solvent separation. Compared to traditional thermal separation processes, membrane separation method offers a lower-cost and more energy-efficient option to separate and purify chemicals. Moreover, membrane separation processes also demonstrate advantages in separating polar solvent mixtures that can form hard-to-separate azeotropic mixtures. Here we focus on the development and characterization of polymeric membranes for the dehydration of polar solvents. Using spin coating ring opening metathesis polymerization (scROMP), thin polymer films can be fabricated in under three minutes on coupon sized supports using cyclic olefin monomers, Grubbs 3rd generation catalyst, and as little as half an mL of solvent per 25 cm² of polymer selective layer.[1-3] The monomer norbornene diacyl chloride (NBDAC) has been utilized in scROMP to form pNBDAC thin film composite membranes. Each repeat unit of pNBDAC has two reactive side groups that can be chemically modified to obtain many desired film compositions. The modifications introduce a class of films with literally hundreds to thousands of variations, many of which could provide promising separation functionality. However, searching for high-performing candidates in such a large design space is overwhelming and requires an efficient strategy to screen and narrow down potential candidates for more careful considerations and characterizations. Hence, a high-throughput screening workflow utilizing molecular dynamics (MD) simulations and machine learning (ML) has been designed to perform a coarse screen of the available polymeric membrane designs, i.e., side chain modifications that can be applied to the pNBDAC membrane. This combinatorial approach has been shown to be highly efficient in shortlisting candidates for further screenings,[4] as well as providing information regarding the synthesis mechanism/pathway and related to the diffusion of solvent mixtures into/through the membranes.

References

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3. Norrman, K.; Ghanbari-Siahkali, A.; Larsen, N. B. 6 Studies of Spin-Coated Polymer Films. Annu. Reports Sect. “C” (Physical Chem. 2005, 101, 174.
4. Quach, C. D., Justin, B. G., et al. High-throughput screening of tribological properties of monolayer films using molecular dynamics and machine learning. The Journal of Chemical Physics vol. 156 154902 (2022).