(659e) Thermally Crosslinked Polymer of Intrinsic Microporosity Membranes for CO2 Separation

Polymers of intrinsic microporosity (PIMs) have seen a growing role in CO₂ separation membranes. However, conventional PIM membranes faces two primary challenges: 1) the moderate CO₂ selectivity of PIM membrane limits the effective separation of CO₂; 2) PIM polymer chain segments undergo swelling and plasticize under high CO₂ feed pressures, leading to a substantial decline in gas selectivity and the loss of separation efficiency. To address these challenges, this presentation focuses on the molecular design of PIMs to establish thermally cross-linked polymer networks to enhance the CO₂ selectivity and plasticization resistance of PIM membranes. Specifically, PIM-1 undergoes hydrolysis to form carboxylated PIM-COOH polymers, followed by esterification to produce monoesterified PIM. These monoesterified PIMs are then thermally ester-crosslinked at various temperatures and durations. Membranes treated at 300°C for 8 h exhibit a CO₂ permeability of 7421 Barrers, with a CO₂/N₂ selectivity of 19.2, significantly surpassing the latest Robeson upper bound. Additionally, the crosslinked membranes demonstrate notably improved CO₂ plasticization resistance, enduring pressures up to 42 bar, in comparison to their uncrosslinked counterparts. Other approaches, such as ring-opening, hydrogen bonding, and multi-covalent cross-linking, will also be explored and discussed. The discoveries from these research hold promise for application in critical areas of CO₂ separation, such as natural gas purification and flue gas CO₂ capture.

References

[1] J. Zhang, Y. Sun, F. Fan, Q. Zhao, G. He, C. Ma*, J. Membr. Sci. 2023, 122115.

[2] L. Wu, X. Chen, Z. Zhang, S. Xu, C. Ma*, N. Li*, J. Membr. Sci., 2021, 634, 119399

[3] X. Chen, Y. Fan, L. Wu, L. Zhang, D. Guan, C. Ma*, N. Li*., Nat. Commun., 2021, 12, 6140