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Macroscopic Ultralight Aerogel Monoliths of Imine‐based Covalent Organic Frameworks
Author(s) -
MartínIllán Jesús Á.,
RodríguezSanMiguel David,
Castillo Oscar,
Beobide Garikoitz,
PerezCarvajal Javier,
Imaz Inhar,
Maspoch Daniel,
Zamora Félix
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202100881
Subject(s) - aerogel , covalent organic framework , materials science , porosity , covalent bond , imine , supercritical fluid , chemical engineering , nanomaterials , toluene , monolith , solvent , supercritical drying , porous medium , composite material , nanotechnology , organic chemistry , chemistry , catalysis , engineering
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 2 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 −3 ), 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 −1 ), with high removal efficiency (ca. 99 %). The same three‐step method can be used to create functional composites of these COF aerogels with nanomaterials.