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Hong T, Lee C, Bak Y, Park G, Lee H, Kang S, Bae TH, Yoon DK, Park JG. On-Demand Tunable Electrical Conductance Anisotropy in a MOF-Polymer Composite. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2309469. [PMID: 38174621 DOI: 10.1002/smll.202309469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 11/27/2023] [Indexed: 01/05/2024]
Abstract
Property optimization through orientation control of metal-organic framework (MOF) crystals that exhibit anisotropic crystal structures continues to garner tremendous interest. Herein, an electric field is utilized to post-synthetically control the orientation of conductive layered Cu3(HHTP)2 (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) crystals dispersed in an electronically insulating poly(ethylene glycol) diacrylate (PEGDA) oligomer matrix. Optical and electrical measurements are performed to investigate the impact of the electric field on the alignment of Cu3(HHTP)2 crystals and the formation of aggregated microstructures, which leads to an ≈5000-fold increase in the conductivity of the composite. Notably, the composite thin-films containing aligned Cu3(HHTP)2 crystals exhibit significant conductivity of ≈10-3 S cm-1 despite the low concentration (≈1 wt.%) of conductive Cu3(HHTP)2. The use of an electric field to align Cu3(HHTP)2 crystals can rapidly generate various desired patterns that exhibit on-demand tunable collective charge transport anisotropy. The findings provide valuable insights toward the manipulation and utilization of conductive MOFs with anisotropic crystal structures for various applications such as adhesive electrical interconnects and microelectronics.
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Affiliation(s)
- Taegyun Hong
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Changjae Lee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Yeongseo Bak
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Geonhyeong Park
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Hongju Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Seunguk Kang
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Tae-Hyun Bae
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Dong Ki Yoon
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Jesse G Park
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
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Anan S, Kurihara T, Yamaguchi M, Kikuchi H, Kokado K. Enhanced Orientation of Liquid Crystals Inside Micropores of Metal-Organic Frameworks Having Thermoresponsivity. Chemistry 2024:e202303277. [PMID: 38179786 DOI: 10.1002/chem.202303277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 01/01/2024] [Accepted: 01/01/2024] [Indexed: 01/06/2024]
Abstract
With the aim of controlling the orientation of liquid crystals (LCs) toward realizing external stimuli-responsive materials with tunable functionalities, we synthesized a composite of LCs and metal-organic frameworks (MOFs) by filling LCs into the pores of MOFs (LC@MOFs) for the first time. The included LCs interact with the MOFs through coordination bonds between the cyano groups of the LCs and the metal ions of the MOFs, enabling the orientation of the LC molecules inside the pores of the MOFs and the realization of birefringence of LC@MOFs. The three-dimensional nanometer interstice frameworks maintained the LC orientation even at temperatures much higher than the isotropic phase transition temperature of bulk LCs. Furthermore, the orientational state changed upon heating or cooling, inducing temperature-dependent birefringence. This study provides a new approach to the development of stimuli-responsive optical materials and stimuli-responsive MOFs.
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Affiliation(s)
- Shizuka Anan
- Department of Advanced Science and Technology, Faculty of Engineering, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku-ku, Nagoya, 468-8511, Japan
| | - Takuya Kurihara
- Division of Material Chemistry, Graduate School of Natural Science and Technology, Kanazawa University Kakuma-machi, Kanazawa, 920-1192, Japan
| | - Masaki Yamaguchi
- Interdisciplinary Graduate School of Engineering Science, Kyushu University, 6-1 Kasuga-koen, Kasuga, 816-8580, Japan
| | - Hirotsugu Kikuchi
- Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasuga-koen, Kasuga, 816-8580, Japan
| | - Kenta Kokado
- Department of Advanced Science and Technology, Faculty of Engineering, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku-ku, Nagoya, 468-8511, Japan
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