Park Sunghwan, Jung Ho Jin, Kim Se Hun, Ly Hoang Vu, Kim Seung-Soo, Kang Dong A, Kwon Young Je, Joo Seunghyeon, Cho Kie Yong, Jeong Hae-Kwon
Artie McFerrin Department of Chemical Engineering and Department of Materials Science and Engineering, Texas A&M University, 3122 TAMU, College Station, TX, 77843-3122, USA.
Department of Energy Chemical Engineering, School of Advanced Science and Technology Convergence, and Convergence Research Center of Mechanical and Chemical Engineering Kyungpook National University, 2559 Gyeongsang-daero, Sangju-si, Gyeongsangbuk-do, 37224, Republic of Korea.
Small. 2025 Sep;21(37):e05746. doi: 10.1002/smll.202505746. Epub 2025 Jul 26.
Zeolitic imidazolate framework-8 (ZIF-8) is a promising material for CH/CH separation; however, its inherent linker flexibility compromises molecular sieving effect. To address this limitation, a novel ZIF-8, namely heterogeneous ZIF-8 (hZIF-8), is developed, consisting of nanocrystalline ZIF-8 phases with a minor amorphous polymer component introduced via in situ coordination. hZIF-8 is synthesized through a Lewis-acid-catalyzed cationic ring-opening polymerization of tetrahydrofuran (THF), generating polytetramethylene ether glycol (PTMEG) chains that competitively coordinate with zinc ions during ZIF-8 crystallization. This coordination-mediated heterogeneous structure exhibits unique characteristics distinct from conventional ZIF-8 and other polymer hybrid MOFs such as PolyMOFs. The polymer phase effectively restricts the linker flexibility of the nanocrystalline phase at the molecular level, leading to significantly enhanced molecular sieving properties. As a result, hZIF-8-containing mixed-matrix membranes (MMMs) exhibit a significant enhancement in CH/CH separation performance, with the separation factor increasing from 13.3 to 75.5 (by 468%) and the CH permeability from 7.4 to 17.4 Barrer (by 135%) at 30 wt.% loading. Furthermore, the intrinsic selectivity of hZIF-8 is predicted to reach ≈3700, representing an order-of-magnitude improvement over that of pristine ZIF-8 (≈180).
沸石咪唑酯骨架材料-8（ZIF-8）是一种用于CH/CH分离的很有前景的材料；然而，其固有的连接体灵活性会影响分子筛效应。为了解决这一局限性，人们开发了一种新型的ZIF-8，即非均相ZIF-8（hZIF-8），它由纳米晶ZIF-8相组成，并通过原位配位引入了少量无定形聚合物成分。hZIF-8是通过四氢呋喃（THF）的路易斯酸催化阳离子开环聚合反应合成的，生成聚四亚甲基醚二醇（PTMEG）链，这些链在ZIF-8结晶过程中与锌离子发生竞争性配位。这种配位介导的非均相结构表现出与传统ZIF-8和其他聚合物杂化金属有机框架（如PolyMOFs）不同的独特特性。聚合物相在分子水平上有效地限制了纳米晶相的连接体灵活性，从而显著提高了分子筛性能。因此，含有hZIF-8的混合基质膜（MMM）在CH/CH分离性能方面有显著提高，在30 wt.%负载量下，分离因子从13.3提高到75.5（提高了468%），CH渗透率从7.4提高到17.4 Barrer（提高了135%）。此外，hZIF-8的固有选择性预计将达到≈3700，比原始ZIF-8（≈180）提高了一个数量级。
