CO2/CH4 Separation Performance in Polymers of Intrinsic Microporosity: All-Atom Simulations on Functional Group Effects

作者：Xiang Liu, Ruifang Shi, Peibin Zhang, Qingwei Gao, Xiaofei Xu, Jing Cui, Shuangliang Zhao · 发表于：Industrial & Engineering Chemistry Research · 年份：2025 · DOI：10.1021/acs.iecr.5c00124 · 被引用次数：6 · 研究领域：Membrane Separation and Gas Transport、Covalent Organic Framework Applications、Carbon Dioxide Capture Technologies

The separation performance of the CO 2 /CH 4 mixture in polymers of intrinsic microporosity (PIMs) is studied by using all-atom molecular dynamics simulations. Eight types of PIMs with different functional groups are considered, namely, cyano, amidoxime, hydroxyl, thioamide, amide, amine, carboxyl, and tetrazole groups. The separation performance of these membranes is mainly controlled by the preferential adsorption of CO 2 over CH 4 . PIM with amidoxime (PIM-AO) and amine (PIM-AM) groups are the best two cases. The permeability selectivity of PIM-AO almost exceeds two times that of the original PIM membrane. The good separation performance is attributed to the strong adsorption of CO 2 in membranes because of the interactions of CO 2 molecules with −OH or −NH 2 in amidoxime. In PIM-AM, the interaction strength of CO 2 to the membrane is strong because of the coupling effect of covalent bonding and hydrogen bonding interactions. To give good separation performance, it is suggested to design PIMs with functional groups having strong interactions or multi-interaction sites to CO 2 .