Huang Shaofeng, Hu Yiming, Tan Li-Li, Wan Shun, Yazdi Sadegh, Jin Yinghua, Zhang Wei
Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States.
State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene (NPU), Xi'an 710072, China.
ACS Appl Mater Interfaces. 2020 Nov 18;12(46):51517-51522. doi: 10.1021/acsami.0c15328. Epub 2020 Nov 6.
A series of covalent organic frameworks substituted with azo groups (AzoCOFs) have been synthesized via imine condensation. The obtained frameworks show crystallinity and high stability. More importantly, the AzoCOFs exhibit exceptionally high ideal adsorption solution theory (IAST) selectivity in adsorption of CH (35-2891) over CH at 273 K and 1 bar, owing to the favorable interactions between azo groups and acetylene molecules. The dependence of the gas adsorption property on pore size and polarity of the frameworks was also studied. The triethylene glycol substituted shows the highest CH/CH selectivity (IAST selectivity of 2891), which represents the highest reported for all porous materials. The AzoCOFs also exhibit high IAST adsorption selectivity of CH/CH (11-20), CH/CH (15-22), and CO/CH (12-37), which is comparable with most porous materials, thus showing their great potential in gas separation applications.
通过亚胺缩合反应合成了一系列含偶氮基团的共价有机骨架材料（AzoCOFs）。所得到的骨架材料表现出结晶性和高稳定性。更重要的是，由于偶氮基团与乙炔分子之间存在有利的相互作用，AzoCOFs在273 K和1 bar条件下对CH（35 - 2891）的吸附相对于CH表现出极高的理想吸附溶液理论（IAST）选择性。还研究了气体吸附性能对骨架材料孔径和极性的依赖性。三甘醇取代的材料表现出最高的CH/CH选择性（IAST选择性为2891），这是所有多孔材料中报道的最高值。AzoCOFs对CH/CH（11 - 20）、CH/CH（15 - 22）和CO/CH（12 - 37）也表现出较高的IAST吸附选择性，与大多数多孔材料相当，因此在气体分离应用中显示出巨大潜力。
