Abstract
Covalent organic frameworks (COFs) are highly modular porous crystalline polymers that are of interest for applications such as charge-storage devices, nanofiltration membranes, and optoelectronic devices. COFs are typically synthesized as microcrystalline powders, which limits their performance in these applications, and their limited solubility precludes large-scale processing into more useful morphologies and devices. We report a general, scalable method to exfoliate two-dimensional imine-linked COF powders by temporarily protonating their linkages. The resulting suspensions were cast into continuous crystalline COF films up to 10 cm in diameter, with thicknesses ranging from 50 nm to 20 μm depending on the suspension composition, concentration, and casting protocol. Furthermore, we demonstrate that the film fabrication process proceeds through a partial depolymerization/repolymerization mechanism, providing mechanically robust films that can be easily separated from their substrates.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 5165-5171 |
| Number of pages | 7 |
| Journal | Angewandte Chemie - International Edition |
| Volume | 59 |
| Issue number | 13 |
| DOIs | |
| State | Published - Mar 23 2020 |
Funding
This research was supported by the National Science Foundation (087147‐16468‐01//CBET‐1706219) and the Northwestern University Materials Research Science and Engineering Center (NSF DMR‐1720139). D.W.B., I.C., and A.M.E. are supported by the Ryan Fellowship and the Northwestern University International Institute for Nanotechnology. I.C. is supported by the NSF Graduate Research Fellowship under grant DGE‐1842165. A.M.E. is supported by the NSF Graduate Research Fellowship under grant DGE‐1324585. Partial support for N.C.F. and L.X.C. is from Chemical, Biological, Geological Sciences Division, Basic Energy Sciences, US Department of Energy under Contract No. DE‐AC02‐06CH11357. Research is supported in part by appointments (D.M.) to the U.S. Army Research Laboratory Research Associate Program administered by the Oak Ridge Associated Universities through a contract with the U.S. Army Research Laboratory. This work made use of the IMSERC at Northwestern University, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS‐1542205), the State of Illinois, and the International Institute for Nanotechnology (IIN), as well as the Keck‐II and SPID facilities of Northwestern University's NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS‐1542205); the MRSEC program (NSF DMR‐1720139) at the Materials Research Center; the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN. This research used resources of the Advanced Photon Source (Sectors 5, 8, and 12), a U.S. Department of Energy (DOE) Office of Science User Facilitiy operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE‐AC02‐06CH11357. Portions of this work were performed at the DuPont‐Northwestern‐Dow Collaborative Access Team (DND‐CAT) located at Sector 5 of the Advanced Photon Source (APS). DND‐CAT is supported by Northwestern University, E.I. DuPont de Nemours & Co., and the Dow Chemical Company. We acknowledge Gatan Inc., Pleasanton, CA, USA for the use of the K3‐IS camera installed at NUANCE. This research was supported by the National Science Foundation (087147-16468-01//CBET-1706219) and the Northwestern University Materials Research Science and Engineering Center (NSF DMR-1720139). D.W.B., I.C., and A.M.E. are supported by the Ryan Fellowship and the Northwestern University International Institute for Nanotechnology. I.C. is supported by the NSF Graduate Research Fellowship under grant DGE-1842165. A.M.E. is supported by the NSF Graduate Research Fellowship under grant DGE-1324585. Partial support for N.C.F. and L.X.C. is from Chemical, Biological, Geological Sciences Division, Basic Energy Sciences, US Department of Energy under Contract No. DE-AC02-06CH11357. Research is supported in part by appointments (D.M.) to the U.S. Army Research Laboratory Research Associate Program administered by the Oak Ridge Associated Universities through a contract with the U.S. Army Research Laboratory. This work made use of the IMSERC at Northwestern University, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205), the State of Illinois, and the International Institute for Nanotechnology (IIN), as well as the Keck-II and SPID facilities of Northwestern University's NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205); the MRSEC program (NSF DMR-1720139) at the Materials Research Center; the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN. This research used resources of the Advanced Photon Source (Sectors 5, 8, and 12), a U.S. Department of Energy (DOE) Office of Science User Facilitiy operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Portions of this work were performed at the DuPont-Northwestern-Dow Collaborative Access Team (DND-CAT) located at Sector 5 of the Advanced Photon Source (APS). DND-CAT is supported by Northwestern University, E.I. DuPont de Nemours & Co., and the Dow Chemical Company. We acknowledge Gatan Inc., Pleasanton, CA, USA for the use of the K3-IS camera installed at NUANCE.
Keywords
- covalent organic frameworks
- exfoliation
- nanosheets
- polymers
- solution processing
ASJC Scopus subject areas
- Catalysis
- General Chemistry