Ultrathin Covalent Organic Framework Membranes via a Multi-Interfacial Engineering Strategy for Gas Separation
Ultrathin Covalent Organic Framework Membranes via a Multi-Interfacial Engineering Strategy for Gas Separation
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DOI：
10.1002/adma.202104946
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发表时间：
2021-09-17
影响因子：
29.4
通讯作者：
Zhao, Dan
中科院分区：
文献类型：
--
作者：
Ying, Yunpan;Peh, Shing Bo;Zhao, Dan
共价有机骨架材料具有高孔隙率、有序排列和高稳定性等优点，是一种很有前途的膜材料。然而，COF相对较大的孔径和复杂的膜制备工艺限制了其在筛选小气体分子方面的应用，即使在实验室规模下也是如此。本文提出了一种多界面工程化的策略，即通过两种不同孔径的COF（TpPa-SO 3 H和TpTG（Cl））的直接逐层界面反应，在相对大孔COF（COF-LZU 1）膜上的COF-COF界面处形成窄孔。在423 K，一个制造的155 nm厚的CO2 COF膜显示H-2渗透高达2163气体渗透单位（GPU）和H-2/CO2的选择性为26，超越了2008年罗伯逊上限。这一策略不仅为H-2分离提供了高性能的膜候选者，而且对其他COF、多孔聚合物及其膜的界面工程和孔工程操作也具有启发意义。
Covalent organic frameworks (COFs) are promising membrane materials due to their high porosity, ordered arrangements, and high stability. However, the relatively large pore size and complicated membrane preparation processes of COFs limit their applications in sieving small gas molecules, even at a lab scale. Herein, a multi-interfacial engineering strategy is proposed, that is, direct layer-by-layer interfacial reaction of two COFs (TpPa-SO3H and TpTG(Cl)) with different pore sizes to form narrowed apertures at the COF-COF interfaces atop a relatively large-pore COF (COF-LZU1) film. At 423 K, one fabricated 155 nm-thick ultrathin COF membrane displays H-2 permeance as high as 2163 gas permeation units (GPU) and a H-2/CO2 selectivity of 26, transcending the 2008 Robeson upper bound. This strategy not only provides high-performance membrane candidates for H-2 separation, but also enlightens the interfacial engineering and pore engineering manipulation for other COFs, porous polymers, and their membranes.