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Lee KM, Marsh ZM, Crenshaw EP, Tohgha UN, Ambulo CP, Wolf SM, Carothers KJ, Limburg HN, McConney ME, Godman NP. Recent Advances in Electro-Optic Response of Polymer-Stabilized Cholesteric Liquid Crystals. MATERIALS (BASEL, SWITZERLAND) 2023; 16:2248. [PMID: 36984126 PMCID: PMC10053326 DOI: 10.3390/ma16062248] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/01/2023] [Accepted: 03/06/2023] [Indexed: 06/18/2023]
Abstract
Cholesteric liquid crystals (CLC) are molecules that can self-assemble into helicoidal superstructures exhibiting circularly polarized reflection. The facile self-assembly and resulting optical properties makes CLCs a promising technology for an array of industrial applications, including reflective displays, tunable mirror-less lasers, optical storage, tunable color filters, and smart windows. The helicoidal structure of CLC can be stabilized via in situ photopolymerization of liquid crystal monomers in a CLC mixture, resulting in polymer-stabilized CLCs (PSCLCs). PSCLCs exhibit a dynamic optical response that can be induced by external stimuli, including electric fields, heat, and light. In this review, we discuss the electro-optic response and potential mechanism of PSCLCs reported over the past decade. Multiple electro-optic responses in PSCLCs with negative or positive dielectric anisotropy have been identified, including bandwidth broadening, red and blue tuning, and switching the reflection notch when an electric field is applied. The reconfigurable optical response of PSCLCs with positive dielectric anisotropy is also discussed. That is, red tuning (or broadening) by applying a DC field and switching by applying an AC field were both observed for the first time in a PSCLC sample. Finally, we discuss the potential mechanism for the dynamic response in PSCLCs.
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Affiliation(s)
- Kyung Min Lee
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, OH 45433, USA
- Azimuth Corporation, Beavercreek, OH 45431, USA
| | - Zachary M. Marsh
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, OH 45433, USA
- Azimuth Corporation, Beavercreek, OH 45431, USA
| | - Ecklin P. Crenshaw
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, OH 45433, USA
- Azimuth Corporation, Beavercreek, OH 45431, USA
| | - Urice N. Tohgha
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, OH 45433, USA
- Azimuth Corporation, Beavercreek, OH 45431, USA
| | - Cedric P. Ambulo
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, OH 45433, USA
- Azimuth Corporation, Beavercreek, OH 45431, USA
| | - Steven M. Wolf
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, OH 45433, USA
- Azimuth Corporation, Beavercreek, OH 45431, USA
| | - Kyle J. Carothers
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, OH 45433, USA
- Azimuth Corporation, Beavercreek, OH 45431, USA
| | - Hannah N. Limburg
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, OH 45433, USA
- Department of Materials Science and Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Michael E. McConney
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, OH 45433, USA
| | - Nicholas P. Godman
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, OH 45433, USA
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Zhang R, Zhang Z, Han J, Yang L, Li J, Song Z, Wang T, Zhu J. Advanced liquid crystal-based switchable optical devices for light protection applications: principles and strategies. LIGHT, SCIENCE & APPLICATIONS 2023; 12:11. [PMID: 36593244 PMCID: PMC9807646 DOI: 10.1038/s41377-022-01032-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 09/18/2022] [Accepted: 11/01/2022] [Indexed: 05/14/2023]
Abstract
With the development of optical technologies, transparent materials that provide protection from light have received considerable attention from scholars. As important channels for external light, windows play a vital role in the regulation of light in buildings, vehicles, and aircrafts. There is a need for windows with switchable optical properties to prevent or attenuate damage or interference to the human eye and light-sensitive instruments by inappropriate optical radiation. In this context, liquid crystals (LCs), owing to their rich responsiveness and unique optical properties, have been considered among the best candidates for advanced light protection materials. In this review, we provide an overview of advances in research on LC-based methods for protection against light. First, we introduce the characteristics of different light sources and their protection requirements. Second, we introduce several classes of light modulation principles based on liquid crystal materials and demonstrate the feasibility of using them for light protection. In addition, we discuss current light protection strategies based on liquid crystal materials for different applications. Finally, we discuss the problems and shortcomings of current strategies. We propose several suggestions for the development of liquid crystal materials in the field of light protection.
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Affiliation(s)
- Ruicong Zhang
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China
| | - Zhibo Zhang
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China
| | - Jiecai Han
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China
| | - Lei Yang
- Research Center of Analysis and Measurement, Harbin Institute of Technology, Harbin, 150080, China
| | - Jiajun Li
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China
| | - Zicheng Song
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China
| | - Tianyu Wang
- School of Energy Science & Engineering, Harbin Institute of Technology, Harbin, 150001, China.
| | - Jiaqi Zhu
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China.
- Key Laboratory of Micro-systems and Micro-structures Manufacturing, Ministry of Education, Harbin, 150080, China.
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Wei Q, Lv P, Zhang Y, Zhang J, Qin Z, de Haan LT, Chen J, Wang D, Xu BB, Broer DJ, Zhou G, Ding L, Zhao W. Facile Stratification-Enabled Emergent Hyper-Reflectivity in Cholesteric Liquid Crystals. ACS APPLIED MATERIALS & INTERFACES 2022; 14:57235-57243. [PMID: 36520981 DOI: 10.1021/acsami.2c16938] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Cholesteric liquid crystals (CLCs) are chiral photonic materials with selective reflection in terms of wavelength and polarization. Helix engineering is often required in order to produce desired properties for CLC materials to be employed for beam steering, light diffraction, scattering, and adaptive or broadband reflection. Here, we demonstrate a novel photopolymerization-enforced stratification (PES)-based strategy to realize helix engineering in a chiral CLC system with initially one handedness of molecular rotation throughout the layer. PES plays a crucial role in driving the chiral dopant bundle consisting of two chiral dopants of opposite handedness to spontaneously phase separate and create a CLC bilayer structure that reflects left- and right-handed circularly polarized light (CPL). The initially hidden chiral information therefore becomes explicit, and hyper-reflectivity, i.e., reflecting both left- and right-handed CPL, successfully emerges from the designed CLC mixture. The PES mechanism can be applied to structure a wide range of liquid crystal (LC) and polymer materials. Moreover, the engineering strategy enables facile programming of the center wavelength of hyper-reflection, patterning, and incorporating stimuli-responsiveness in the optical device. Hence, the engineered hyper-reflective CLCs offer great promise for future applications, such as digital displays, lasing, optical storage, and smart windows.
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Affiliation(s)
- Qunmei Wei
- SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou Higher Education Mega Center, No. 378, West Waihuan Road, 510006 Guangzhou, China
| | - Pengrong Lv
- Stimuli-responsive Functional Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Den Dolech 2, Eindhoven 5600 MB, The Netherlands
| | - Yang Zhang
- SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou Higher Education Mega Center, No. 378, West Waihuan Road, 510006 Guangzhou, China
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, P. R. China
| | - Jiwen Zhang
- SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou Higher Education Mega Center, No. 378, West Waihuan Road, 510006 Guangzhou, China
| | - Zhuofan Qin
- Mechanical and Construction Engineering, Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne NE1 8ST, U.K
| | - Laurens T de Haan
- SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou Higher Education Mega Center, No. 378, West Waihuan Road, 510006 Guangzhou, China
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, P. R. China
| | - Jiawen Chen
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, P. R. China
| | - Ding Wang
- Mechanical and Construction Engineering, Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne NE1 8ST, U.K
| | - Ben Bin Xu
- Mechanical and Construction Engineering, Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne NE1 8ST, U.K
| | - Dirk J Broer
- SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou Higher Education Mega Center, No. 378, West Waihuan Road, 510006 Guangzhou, China
- Stimuli-responsive Functional Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Den Dolech 2, Eindhoven 5600 MB, The Netherlands
| | - Guofu Zhou
- SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou Higher Education Mega Center, No. 378, West Waihuan Road, 510006 Guangzhou, China
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, P. R. China
- Shenzhen Guohua Optoelectronics Tech. Co. Ltd., Shenzhen 518110, P. R. China
| | - Liming Ding
- Center for Excellence in Nanoscience (CAS), Key Laboratory of Nanosystem and Hierarchical Fabrication (CAS), National Center for Nanoscience and Technology, Beijing 100190, China
| | - Wei Zhao
- SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou Higher Education Mega Center, No. 378, West Waihuan Road, 510006 Guangzhou, China
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, P. R. China
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4
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Transparent UV-blocking photonic film based on reflection of cholesteric liquid crystals. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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5
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Zhao W, de Haan LT, Broer DJ, Zhang Y, Lv P, Zhou G. Photopolymerization-enforced stratification in liquid crystal materials. Prog Polym Sci 2021. [DOI: 10.1016/j.progpolymsci.2021.101365] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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6
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Liu B, Yang T, Mu X, Mai Z, Li H, Wang Y, Zhou G. Smart Supramolecular Self-Assembled Nanosystem: Stimulus-Responsive Hydrogen-Bonded Liquid Crystals. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:448. [PMID: 33578814 PMCID: PMC7916626 DOI: 10.3390/nano11020448] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/22/2021] [Accepted: 02/08/2021] [Indexed: 12/18/2022]
Abstract
In a liquid crystal (LC) state, specific orientations and alignments of LC molecules produce outstanding anisotropy in structure and properties, followed by diverse optoelectronic functions. Besides organic LC molecules, other nonclassical components, including inorganic nanomaterials, are capable of self-assembling into oriented supramolecular LC mesophases by non-covalent interactions. Particularly, huge differences in size, shape, structure and properties within these components gives LC supramolecules higher anisotropy and feasibility. Therefore, hydrogen bonds have been viewed as the best and the most common option for supramolecular LCs, owing to their high selectivity and directionality. In this review, we summarize the newest advances in self-assembled structure, stimulus-responsive capability and application of supramolecular hydrogen-bonded LC nanosystems, to provide novel and immense potential for advancing LC technology.
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Affiliation(s)
- Bing Liu
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China; (B.L.); (T.Y.); (X.M.); (Z.M.); (G.Z.)
- National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Tao Yang
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China; (B.L.); (T.Y.); (X.M.); (Z.M.); (G.Z.)
- National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Xin Mu
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China; (B.L.); (T.Y.); (X.M.); (Z.M.); (G.Z.)
- National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Zhijian Mai
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China; (B.L.); (T.Y.); (X.M.); (Z.M.); (G.Z.)
- National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Hao Li
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China; (B.L.); (T.Y.); (X.M.); (Z.M.); (G.Z.)
- National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Yao Wang
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China; (B.L.); (T.Y.); (X.M.); (Z.M.); (G.Z.)
- National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Guofu Zhou
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China; (B.L.); (T.Y.); (X.M.); (Z.M.); (G.Z.)
- National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, China
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7
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Wang L, Urbas AM, Li Q. Nature-Inspired Emerging Chiral Liquid Crystal Nanostructures: From Molecular Self-Assembly to DNA Mesophase and Nanocolloids. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1801335. [PMID: 30160812 DOI: 10.1002/adma.201801335] [Citation(s) in RCA: 162] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 05/17/2018] [Indexed: 05/22/2023]
Abstract
Liquid crystals (LCs) are omnipresent in living matter, whose chirality is an elegant and distinct feature in certain plant tissues, the cuticles of crabs, beetles, arthropods, and beyond. Taking inspiration from nature, researchers have recently devoted extensive efforts toward developing chiral liquid crystalline materials with self-organized nanostructures and exploring their potential applications in diverse fields ranging from dynamic photonics to energy and safety issues. In this review, an account on the state of the art of emerging chiral liquid crystalline nanostructured materials and their technological applications is provided. First, an overview on the significance of chiral liquid crystalline architectures in various living systems is given. Then, the recent significant progress in different chiral liquid crystalline systems including thermotropic LCs (cholesteric LCs, cubic blue phases, achiral bent-core LCs, etc.) and lyotropic LCs (DNA LCs, nanocellulose LCs, and graphene oxide LCs) is showcased. The review concludes with a perspective on the future scope, opportunities, and challenges in these truly advanced functional soft materials and their promising applications.
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Affiliation(s)
- Ling Wang
- Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, OH, 44242, USA
| | - Augustine M Urbas
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, OH, 45433, USA
| | - Quan Li
- Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, OH, 44242, USA
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Yu M, Wang L, Nemati H, Yang H, Bunning T, Yang DK. Effects of polymer network on electrically induced reflection band broadening of cholesteric liquid crystals. ACTA ACUST UNITED AC 2017. [DOI: 10.1002/polb.24317] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Meina Yu
- Department of Materials Science and Engineering; College of Engineering, and Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University; Beijing 100871 People's Republic of China
- Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University; Kent Ohio 44242
| | - Ling Wang
- Department of Materials Science and Engineering; College of Engineering, and Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University; Beijing 100871 People's Republic of China
- Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University; Kent Ohio 44242
| | - Hossein Nemati
- Air Force Research Laboratory; Materials and Manufacturing Directorate, Wright Patterson Air Force Base; Ohio 45433
| | - Huai Yang
- Department of Materials Science and Engineering; College of Engineering, and Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University; Beijing 100871 People's Republic of China
| | - Timothy Bunning
- Air Force Research Laboratory; Materials and Manufacturing Directorate, Wright Patterson Air Force Base; Ohio 45433
| | - Deng-Ke Yang
- Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University; Kent Ohio 44242
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9
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Balamurugan R, Liu JH. A review of the fabrication of photonic band gap materials based on cholesteric liquid crystals. REACT FUNCT POLYM 2016. [DOI: 10.1016/j.reactfunctpolym.2016.04.012] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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10
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Yu M, Zhou X, Jiang J, Yang H, Yang DK. Matched elastic constants for a perfect helical planar state and a fast switching time in chiral nematic liquid crystals. SOFT MATTER 2016; 12:4483-4488. [PMID: 27116620 DOI: 10.1039/c6sm00546b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Chiral nematic liquid crystals possess a self-assembled helical structure and exhibit unique selective reflection in visible and infrared light regions. Their optical properties can be electrically tuned. The tuning involves the unwinding and restoring of the helical structure. We carried out an experimental study on the mechanism of the restoration of the helical structure. We constructed chiral nematic liquid crystals with variable elastic constants by doping bent-dimers and studied their impact on the restoration. With matched twist and bend elastic constants, the helical structure can be restored dramatically fast from the field-induced homeotropic state. Furthermore, defects can be eliminated to produce a perfect planar state which exhibits high selective reflection.
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Affiliation(s)
- Meina Yu
- Department of Materials Science and Engineering, College of Engineering, and Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing 100871, P. R. China and Chemical Physics Interdisciplinary Program and Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA.
| | - Xiaochen Zhou
- Chemical Physics Interdisciplinary Program and Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA.
| | - Jinghua Jiang
- Chemical Physics Interdisciplinary Program and Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA.
| | - Huai Yang
- Department of Materials Science and Engineering, College of Engineering, and Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing 100871, P. R. China
| | - Deng-Ke Yang
- Chemical Physics Interdisciplinary Program and Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA.
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11
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Fu D, Li J, Wei J, Guo J. Effects of terminal chain length in hydrogen-bonded chiral switches on phototunable behavior of chiral nematic liquid crystals: helicity inversion and phase transition. SOFT MATTER 2015; 11:3034-3045. [PMID: 25743076 DOI: 10.1039/c5sm00128e] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A novel series of photoresponsive chiral switches are fabricated by a facile hydrogen-bonded (H-bonded) assembly method, in which the binaphthyl azobenzene molecule is used as the proton acceptor, and binaphthyl acids with opposite chiral configuration are proton donors. We find that the helical twisted power of H-bonded chiral switches and the helical handedness of induced chiral nematic liquid crystals (N*-LCs) are mainly determined by the terminal flexible chain length in proton donors of binaphthyl acids. Controlling the lengths of the terminal flexible chain leads to different photoswitching behaviors by light irradiation, such as a helical inversion in the N*-LCs and a phase transition from N*-LCs to nematic LCs. This is mainly because of chiral counteraction and intensity attenuation of opposite chiral configurations between the proton acceptor and proton donor during UV-vis irradiation. Additionally, the thermal switching behavior of N*-LCs doped with H-bonded chiral switches is also demonstrated, and the related tuning mechanism may be attributed to the H-bonded effect and the changes in a dihedral angle of the binaphthyl rings. This facile assembly approach provides a new way for the fabrication of functional chiral switches for photonic applications.
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Affiliation(s)
- Dengwei Fu
- College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, P. R. China.
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12
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A temperature and pH double sensitive cholesteric polymer film from a photopolymerizable chiral hydrogen-bonded assembly. CHINESE JOURNAL OF POLYMER SCIENCE 2013. [DOI: 10.1007/s10118-013-1244-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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13
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Guo J, Zhang J, Zhang Q, Jiang N, Wei J. Fabrication of cholesteric liquid crystal microcapsulates by interfacial polymerization and potential as photonic materials. RSC Adv 2013. [DOI: 10.1039/c3ra43502d] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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14
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Mitov M. Cholesteric liquid crystals with a broad light reflection band. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2012; 24:6260-76. [PMID: 23090724 DOI: 10.1002/adma.201202913] [Citation(s) in RCA: 203] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 09/04/2012] [Indexed: 05/22/2023]
Abstract
The cholesteric-liquid-crystalline structure, which concerns the organization of chromatin, collagen, chitin, or cellulose, is omnipresent in living matter. In technology, it is found in temperature and pressure sensors, supertwisted nematic liquid crystal displays, optical filters, reflective devices, or cosmetics. A cholesteric liquid crystal reflects light because of its helical structure. The reflection is selective - the bandwidth is limited to a few tens of nanometers and the reflectance is equal to at most 50% for unpolarized incident light, which is a consequence of the polarization-selectivity rule. These limits must be exceeded for innovative applications like polarizer-free reflective displays, broadband polarizers, optical data storage media, polarization-independent devices, stealth technologies, or smart switchable reflective windows to control solar light and heat. Novel cholesteric-liquid-crystalline architectures with the related fabrication procedures must therefore be developed. This article reviews solutions found in living matter and laboratories to broaden the bandwidth around a central reflection wavelength, do without the polarization-selectivity rule and go beyond the reflectance limit.
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Affiliation(s)
- Michel Mitov
- Centre d'Elaboration de Matériaux et d'Etudes Structurales, UPR, Toulouse, France.
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15
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Broer DJ, Bastiaansen CMW, Debije MG, Schenning APHJ. Functional organic materials based on polymerized liquid-crystal monomers: supramolecular hydrogen-bonded systems. Angew Chem Int Ed Engl 2012; 51:7102-9. [PMID: 22588947 DOI: 10.1002/anie.201200883] [Citation(s) in RCA: 154] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Indexed: 11/10/2022]
Abstract
Functional organic materials are of great interest for a variety of applications. To obtain precise functional properties, well-defined hierarchically ordered supramolecular materials are crucial. The self-assembly of liquid crystals has proven to be an extremely useful tool in the development of well-defined nanostructured materials. We have chosen the illustrative example of photopolymerizable hydrogen-bonding mesogens to show that a wide variety of functional materials can be made from a relatively simple set of building blocks. Upon mixing these compounds with other reactive mesogens, nematic, chiral nematic, and smectic or columnar liquid-crystalline phases can be formed that can be applied as actuators, sensors and responsive reflectors, and nanoporous membranes, respectively.
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Affiliation(s)
- Dirk J Broer
- Laboratory of Functional Organic Materials and Devices, Eindhoven University of Technology, P.O. Box 513, 5600 MB, The Netherlands
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16
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Broer DJ, Bastiaansen CMW, Debije MG, Schenning APHJ. Funktionelle organische Materialien auf der Basis polymerisierter flüssigkristalliner Monomere: supramolekulare wasserstoffverbrückte Systeme. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201200883] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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17
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Herzer N, Guneysu H, Davies DJD, Yildirim D, Vaccaro AR, Broer DJ, Bastiaansen CWM, Schenning APHJ. Printable optical sensors based on H-bonded supramolecular cholesteric liquid crystal networks. J Am Chem Soc 2012; 134:7608-11. [PMID: 22519954 DOI: 10.1021/ja301845n] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A printable H-bonded cholesteric liquid crystal (CLC) polymer film has been fabricated that, after conversion to a hygroscopic polymer salt film, responds to temperature and humidity by changing its reflection color. Fast-responding humidity sensors have been made in which the reflection color changes between green and yellow depending on the relative humidity. The change in reflection band is a result of a change in helix pitch in the film due to absorption and desorption of water, resulting in swelling/deswelling of the film material. When the polymer salt was saturated with water, a red-reflecting film was obtained that can potentially act as a time/temperature integrator. Finally, the films were printed on a foil, showing the potential application of supramolecular CLC materials as low-cost, printable, battery-free optical sensors.
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Affiliation(s)
- Nicole Herzer
- Functional Organic Materials & Devices, Eindhoven University of Technology, PO Box 513, Eindhoven, The Netherlands
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Agez G, Mitov M. Cholesteric Liquid Crystalline Materials with a Dual Circularly Polarized Light Reflection Band Fixed at Room Temperature. J Phys Chem B 2011; 115:6421-6. [DOI: 10.1021/jp2014622] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gonzague Agez
- Centre d’Elaboration de Matériaux et d’Etudes Structurales (CEMES), Centre National de la Recherche Scientifique (CNRS), University of Toulouse, 29 rue J. Marvig, F-31055 Toulouse cedex 4, France
| | - Michel Mitov
- Centre d’Elaboration de Matériaux et d’Etudes Structurales (CEMES), Centre National de la Recherche Scientifique (CNRS), University of Toulouse, 29 rue J. Marvig, F-31055 Toulouse cedex 4, France
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