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Guo Y, Afghah S, Xiang J, Lavrentovich OD, Selinger RLB, Wei QH. Cholesteric liquid crystals in rectangular microchannels: skyrmions and stripes. SOFT MATTER 2016; 12:6312-6320. [PMID: 27396898 DOI: 10.1039/c6sm01190j] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this paper, we present experimental and numerical studies on the microstructures of a cholesteric liquid crystal (CLC) confined in rectangular micron-channels. By using a sequence of microfabrication techniques we fabricated the micro-sized channels with accurately controlled size, aspect ratio and homeotropic surface anchoring. Through optical microscopic studies we established a phase diagram for the liquid crystal defect textures as a function of the channel depth and width. For the channel width larger than ∼2 times the cholesteric pitch p, the LC molecules are oriented primarily vertical to the channel when the channel depth is below 0.75p, form bubble domain defects when the channel depth is around 0.75p, and form stripe textures when the cell depth is above the cholesteric pitch p. In addition, the bubble domain size and the stripe texture periodicity are found to grow with the increase of the channel width. For the channel width smaller than ∼2p and the channel depth between 0.6p to 1.1p, no textures can be observed in the channels. Numerical simulations based on a director tensor relaxation approach yield detailed molecular director fields, and show that the bubble domain defects are baby-skyrmions and that the stripes are the first type of cholesteric fingerprints. A comparison with previous experiments and numerical simulations indicates that the size of the microchannels also influences what type of soliton-like topological textures form in the CLCs confined in the channels.
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Affiliation(s)
- Yubing Guo
- Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA.
| | - Sajedeh Afghah
- Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA.
| | - Jie Xiang
- Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA.
| | | | | | - Qi-Huo Wei
- Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA.
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Park SJ, Hwang SH, Kim N, Kuo SW, Kim HY, Park SK, Kim YJ, Nah C, Lee JH, Jeong KU. Columnar Structures from Asymmetrically Tapered Biphenylamide. J Phys Chem B 2009; 113:13499-508. [DOI: 10.1021/jp905672s] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Soo-Jin Park
- Polymer Materials Fusion Research Center and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea, Department of Polymer Science and Engineering, Dankook University, Yongin 448-701, Korea, Department of Polymer Engineering, The University of Akron, Akron, Ohio 44325-0301, Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, and Department of Textile Engineering, Chonbuk National University,
| | - Seok-Ho Hwang
- Polymer Materials Fusion Research Center and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea, Department of Polymer Science and Engineering, Dankook University, Yongin 448-701, Korea, Department of Polymer Engineering, The University of Akron, Akron, Ohio 44325-0301, Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, and Department of Textile Engineering, Chonbuk National University,
| | - Namil Kim
- Polymer Materials Fusion Research Center and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea, Department of Polymer Science and Engineering, Dankook University, Yongin 448-701, Korea, Department of Polymer Engineering, The University of Akron, Akron, Ohio 44325-0301, Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, and Department of Textile Engineering, Chonbuk National University,
| | - Shiao-Wei Kuo
- Polymer Materials Fusion Research Center and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea, Department of Polymer Science and Engineering, Dankook University, Yongin 448-701, Korea, Department of Polymer Engineering, The University of Akron, Akron, Ohio 44325-0301, Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, and Department of Textile Engineering, Chonbuk National University,
| | - Hak Yong Kim
- Polymer Materials Fusion Research Center and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea, Department of Polymer Science and Engineering, Dankook University, Yongin 448-701, Korea, Department of Polymer Engineering, The University of Akron, Akron, Ohio 44325-0301, Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, and Department of Textile Engineering, Chonbuk National University,
| | - Seul-Ki Park
- Polymer Materials Fusion Research Center and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea, Department of Polymer Science and Engineering, Dankook University, Yongin 448-701, Korea, Department of Polymer Engineering, The University of Akron, Akron, Ohio 44325-0301, Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, and Department of Textile Engineering, Chonbuk National University,
| | - Young-Jin Kim
- Polymer Materials Fusion Research Center and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea, Department of Polymer Science and Engineering, Dankook University, Yongin 448-701, Korea, Department of Polymer Engineering, The University of Akron, Akron, Ohio 44325-0301, Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, and Department of Textile Engineering, Chonbuk National University,
| | - Changwoon Nah
- Polymer Materials Fusion Research Center and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea, Department of Polymer Science and Engineering, Dankook University, Yongin 448-701, Korea, Department of Polymer Engineering, The University of Akron, Akron, Ohio 44325-0301, Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, and Department of Textile Engineering, Chonbuk National University,
| | - Joong Hee Lee
- Polymer Materials Fusion Research Center and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea, Department of Polymer Science and Engineering, Dankook University, Yongin 448-701, Korea, Department of Polymer Engineering, The University of Akron, Akron, Ohio 44325-0301, Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, and Department of Textile Engineering, Chonbuk National University,
| | - Kwang-Un Jeong
- Polymer Materials Fusion Research Center and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea, Department of Polymer Science and Engineering, Dankook University, Yongin 448-701, Korea, Department of Polymer Engineering, The University of Akron, Akron, Ohio 44325-0301, Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, and Department of Textile Engineering, Chonbuk National University,
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Hwang SH, Park SJ, Kim HY, Kuo SW, Lee SH, Lee MH, Jeong KU. Phase Behaviors and Structures of a Symmetrically Tapered Biphenylamide. J Phys Chem B 2009; 113:5843-54. [DOI: 10.1021/jp900666c] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Seok-Ho Hwang
- Polymer Materials Fusion Research Center and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea; Chonan R&D Center, Korea Institute of Industrial Technology, Chonan 330-825, Korea; Department of Textile Engineering, Chonbuk National University, Jeonju 561-756, Korea; and Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
| | - Soo-Jin Park
- Polymer Materials Fusion Research Center and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea; Chonan R&D Center, Korea Institute of Industrial Technology, Chonan 330-825, Korea; Department of Textile Engineering, Chonbuk National University, Jeonju 561-756, Korea; and Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
| | - Hak Yong Kim
- Polymer Materials Fusion Research Center and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea; Chonan R&D Center, Korea Institute of Industrial Technology, Chonan 330-825, Korea; Department of Textile Engineering, Chonbuk National University, Jeonju 561-756, Korea; and Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
| | - Shiao-Wei Kuo
- Polymer Materials Fusion Research Center and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea; Chonan R&D Center, Korea Institute of Industrial Technology, Chonan 330-825, Korea; Department of Textile Engineering, Chonbuk National University, Jeonju 561-756, Korea; and Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
| | - Seung Hee Lee
- Polymer Materials Fusion Research Center and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea; Chonan R&D Center, Korea Institute of Industrial Technology, Chonan 330-825, Korea; Department of Textile Engineering, Chonbuk National University, Jeonju 561-756, Korea; and Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
| | - Myong-Hoon Lee
- Polymer Materials Fusion Research Center and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea; Chonan R&D Center, Korea Institute of Industrial Technology, Chonan 330-825, Korea; Department of Textile Engineering, Chonbuk National University, Jeonju 561-756, Korea; and Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
| | - Kwang-Un Jeong
- Polymer Materials Fusion Research Center and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 561-756, Korea; Chonan R&D Center, Korea Institute of Industrial Technology, Chonan 330-825, Korea; Department of Textile Engineering, Chonbuk National University, Jeonju 561-756, Korea; and Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
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