Dynamic Response of Graphitic Flakes in Nematic Liquid Crystals: Confinement and Host Effect
Electric field-induced reorientation of suspended graphitic (GP) flakes and its relaxation back to the original state in a nematic liquid crystal (NLC) host are of interest not only in academia, but also in industrial applications, such as polarizer-free and optical film-free displays, and electro-o...
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| Format: | Article |
| Language: | English |
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MDPI AG
2017-09-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/7/9/250 |
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| author | Weiwei Tie Surjya Sarathi Bhattacharyya Yuanhao Gao Zhi Zheng Eun Jeong Shin Tae Hyung Kim MinSu Kim Joong Hee Lee Seung Hee Lee |
| author_facet | Weiwei Tie Surjya Sarathi Bhattacharyya Yuanhao Gao Zhi Zheng Eun Jeong Shin Tae Hyung Kim MinSu Kim Joong Hee Lee Seung Hee Lee |
| author_sort | Weiwei Tie |
| collection | DOAJ |
| description | Electric field-induced reorientation of suspended graphitic (GP) flakes and its relaxation back to the original state in a nematic liquid crystal (NLC) host are of interest not only in academia, but also in industrial applications, such as polarizer-free and optical film-free displays, and electro-optic light modulators. As the phenomenon has been demonstrated by thorough observation, the detailed study of the physical properties of the host NLC (the magnitude of dielectric anisotropy, elastic constants, and rotational viscosity), the size of the GP flakes, and cell thickness, are urgently required to be explored and investigated. Here, we demonstrate that the response time of GP flakes reorientation associated with an NLC host can be effectively enhanced by controlling the physical properties. In a vertical field-on state, higher dielectric anisotropy and higher elasticity of NLC give rise to quicker reorientation of the GP flakes (switching from planar to vertical alignment) due to the field-induced coupling effect of interfacial Maxwell-Wagner polarization and NLC reorientation. In a field off-state, lower rotational viscosity of NLC and lower cell thickness can help to reduce the decay time of GP flakes reoriented from vertical to planar alignment. This is mainly attributed to strong coupling between GP flakes and NLC originating from the strong π-π interaction between benzene rings in the honeycomb-like graphene structure and in NLC molecules. The high-uniformity of reoriented GP flakes exhibits a possibility of new light modulation with a relatively faster response time in the switching process and, thus, it can show potential application in field-induced memory and modulation devices. |
| first_indexed | 2024-12-10T14:31:51Z |
| format | Article |
| id | doaj.art-a924e5be97e0461eb40d2be0a720db71 |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-12-10T14:31:51Z |
| publishDate | 2017-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-a924e5be97e0461eb40d2be0a720db712022-12-22T01:44:55ZengMDPI AGNanomaterials2079-49912017-09-017925010.3390/nano7090250nano7090250Dynamic Response of Graphitic Flakes in Nematic Liquid Crystals: Confinement and Host EffectWeiwei Tie0Surjya Sarathi Bhattacharyya1Yuanhao Gao2Zhi Zheng3Eun Jeong Shin4Tae Hyung Kim5MinSu Kim6Joong Hee Lee7Seung Hee Lee8Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Institute of Surface Micro and Nano Materials, College of Advanced Materials and Energy, Xuchang University, Xuchang 461000, Henan, ChinaKey Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Institute of Surface Micro and Nano Materials, College of Advanced Materials and Energy, Xuchang University, Xuchang 461000, Henan, ChinaKey Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Institute of Surface Micro and Nano Materials, College of Advanced Materials and Energy, Xuchang University, Xuchang 461000, Henan, ChinaKey Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Institute of Surface Micro and Nano Materials, College of Advanced Materials and Energy, Xuchang University, Xuchang 461000, Henan, ChinaApplied Materials Institute for BIN Convergence, Department of BIN Convergence Technology and Graduate School of Printable and Flexible Electronics, Chonbuk National University, Jeonju 561-756, Jeonbuk, KoreaApplied Materials Institute for BIN Convergence, Department of BIN Convergence Technology and Graduate School of Printable and Flexible Electronics, Chonbuk National University, Jeonju 561-756, Jeonbuk, KoreaApplied Materials Institute for BIN Convergence, Department of BIN Convergence Technology and Graduate School of Printable and Flexible Electronics, Chonbuk National University, Jeonju 561-756, Jeonbuk, KoreaApplied Materials Institute for BIN Convergence, Department of BIN Convergence Technology and Graduate School of Printable and Flexible Electronics, Chonbuk National University, Jeonju 561-756, Jeonbuk, KoreaApplied Materials Institute for BIN Convergence, Department of BIN Convergence Technology and Graduate School of Printable and Flexible Electronics, Chonbuk National University, Jeonju 561-756, Jeonbuk, KoreaElectric field-induced reorientation of suspended graphitic (GP) flakes and its relaxation back to the original state in a nematic liquid crystal (NLC) host are of interest not only in academia, but also in industrial applications, such as polarizer-free and optical film-free displays, and electro-optic light modulators. As the phenomenon has been demonstrated by thorough observation, the detailed study of the physical properties of the host NLC (the magnitude of dielectric anisotropy, elastic constants, and rotational viscosity), the size of the GP flakes, and cell thickness, are urgently required to be explored and investigated. Here, we demonstrate that the response time of GP flakes reorientation associated with an NLC host can be effectively enhanced by controlling the physical properties. In a vertical field-on state, higher dielectric anisotropy and higher elasticity of NLC give rise to quicker reorientation of the GP flakes (switching from planar to vertical alignment) due to the field-induced coupling effect of interfacial Maxwell-Wagner polarization and NLC reorientation. In a field off-state, lower rotational viscosity of NLC and lower cell thickness can help to reduce the decay time of GP flakes reoriented from vertical to planar alignment. This is mainly attributed to strong coupling between GP flakes and NLC originating from the strong π-π interaction between benzene rings in the honeycomb-like graphene structure and in NLC molecules. The high-uniformity of reoriented GP flakes exhibits a possibility of new light modulation with a relatively faster response time in the switching process and, thus, it can show potential application in field-induced memory and modulation devices.https://www.mdpi.com/2079-4991/7/9/250graphitic flakesliquid crystalMaxwell-Wagner polarizationdynamic response |
| spellingShingle | Weiwei Tie Surjya Sarathi Bhattacharyya Yuanhao Gao Zhi Zheng Eun Jeong Shin Tae Hyung Kim MinSu Kim Joong Hee Lee Seung Hee Lee Dynamic Response of Graphitic Flakes in Nematic Liquid Crystals: Confinement and Host Effect Nanomaterials graphitic flakes liquid crystal Maxwell-Wagner polarization dynamic response |
| title | Dynamic Response of Graphitic Flakes in Nematic Liquid Crystals: Confinement and Host Effect |
| title_full | Dynamic Response of Graphitic Flakes in Nematic Liquid Crystals: Confinement and Host Effect |
| title_fullStr | Dynamic Response of Graphitic Flakes in Nematic Liquid Crystals: Confinement and Host Effect |
| title_full_unstemmed | Dynamic Response of Graphitic Flakes in Nematic Liquid Crystals: Confinement and Host Effect |
| title_short | Dynamic Response of Graphitic Flakes in Nematic Liquid Crystals: Confinement and Host Effect |
| title_sort | dynamic response of graphitic flakes in nematic liquid crystals confinement and host effect |
| topic | graphitic flakes liquid crystal Maxwell-Wagner polarization dynamic response |
| url | https://www.mdpi.com/2079-4991/7/9/250 |
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