Martín-Illán Jesús Á, Rodríguez-San-Miguel David, Castillo Oscar, Beobide Garikoitz, Perez-Carvajal Javier, Imaz Inhar, Maspoch Daniel, Zamora Félix
Departamento de Química Inorgánica, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
Departamento de Química Inorgánica, Universidad del País Vasco (UPV/EHU), Apartado 644, 48080, Bilbao, Spain.
Angew Chem Int Ed Engl. 2021 Jun 14;60(25):13969-13977. doi: 10.1002/anie.202100881. Epub 2021 Apr 28.
The use of covalent organic frameworks (COFs) in practical applications demands shaping them into macroscopic objects, which remains challenging. Herein, we report a simple three-step method to produce COF aerogels, based on sol-gel transition, solvent-exchange, and supercritical CO drying, in which 2D imine-based COF sheets link together to form hierarchical porous structures. The resultant COF aerogel monoliths have extremely low densities (ca. 0.02 g cm ), high porosity (total porosity values of ca. 99 %), and mechanically behave as elastic materials under a moderate strain (<25-35 %) but become plastic under greater strain. Moreover, these COF aerogels maintain the micro- and meso-porosity of their constituent COFs, and show excellent absorption capacity (e.g. toluene uptake: 32 g g ), with high removal efficiency (ca. 99 %). The same three-step method can be used to create functional composites of these COF aerogels with nanomaterials.
将共价有机框架（COF）应用于实际需要将其加工成宏观物体，这仍然具有挑战性。在此，我们报道了一种简单的三步法来制备COF气凝胶，该方法基于溶胶-凝胶转变、溶剂交换和超临界CO2干燥，其中二维亚胺基COF片层连接在一起形成分级多孔结构。所得的COF气凝胶整体具有极低的密度（约0.02 g/cm³）、高孔隙率（总孔隙率约为99%），并且在中等应变（<25%-35%）下表现为弹性材料，但在更大应变下变为塑性材料。此外，这些COF气凝胶保留了其组成COF的微孔和介孔结构，并表现出优异的吸附能力（例如甲苯吸附量：32 g/g），去除效率高（约99%）。相同的三步法可用于制备这些COF气凝胶与纳米材料的功能复合材料。
