Biomimetic Synthesis of Sub-20 nm Covalent Organic Frameworks in Water
This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of the American Chemical Society, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/jacs.9b12389 ; Covalent organic frameworks (COFs) are commonly synthesized under harsh conditions yielding unprocessable powders. Control in their crystallization process and growth has been limited to studies conducted in hazardous organic solvents. Herein, we report a one-pot synthetic method that yields stable aqueous colloidal solutions of sub-20 nm crystalline imine-based COF particles at room temperature and ambient pressure. Additionally, through the combination of experimental and computational studies, we investigated the mechanisms and forces underlying the formation of such imine-based COF colloids in water. Further, we show that our method can be used to process the colloidal solution into 2D and 3D COF shapes as well as to generate a COF ink that can be directly printed onto surfaces. These findings should open new vistas in COF chemistry, enabling new application areas ; This work was supported by the European Union (ERC-2015-STG microCrysFact 677020), the Swiss National Science Foundation (Project No. 200021_181988), ETH Zürich and Ministry of Science, Innovation and Universities MICINN (MAT2016-77608-C3-1P). R.P. acknowledges the Spanish MINECO (Grant No. CTQ2017—88948-P). A.E.P.P. acknowledges a TALENTO grant (2017-T1/IND5148) from Comunidad de Madrid. I.S. acknowledges the Ministry of Human Capacities of Hungary (20391-/2018/FEKUSTRAT). G.M.P. acknowledges the funding received by the Swiss National Science Foundation (SNSF grant number 200021_175735) and by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 818776 - DYNAPOL). D.M. acknowledges financial support from the European Union (ERC-Co 615954). ICN2 is supported by the Severo Ochoa program from the Spanish MINECO (Grant No. SEV-2017-0706). S.P. acknowledges funding from a Consolidator Grant from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant Agreement No. 771565). We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Synchrotron X-ray diffraction experiments with COF-TAPB-BTCA were carried out at the beamline P02.1 PETRA III under the proposal I-20170717 EC. We acknowledge Jaume Caelles for SAXS/WAXS measurements performed at IQAC–CSIC.