1
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Chen X, Zhang S, Chen X, Li Q. Tunable Circularly Polarized Luminescent Supramolecular Systems: Approaches and Applications. CHEMPHOTOCHEM 2022. [DOI: 10.1002/cptc.202100256] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Xu‐Man Chen
- Institute of Advanced Materials and School of Chemistry and Chemical Engineering Southeast University Nanjing 211189 China
| | - Shu Zhang
- Institute of Advanced Materials and School of Chemistry and Chemical Engineering Southeast University Nanjing 211189 China
| | - Xiao Chen
- Institute of Advanced Materials and School of Chemistry and Chemical Engineering Southeast University Nanjing 211189 China
| | - Quan Li
- Institute of Advanced Materials and School of Chemistry and Chemical Engineering Southeast University Nanjing 211189 China
- Advanced Materials and Liquid Crystal Institute and Chemical Physics Interdisciplinary Program Kent State University Kent OH 44242 USA
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2
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Sasidharan AK, Mathew J, Achalkumar AS, Mathews M. Synthesis and Liquid Crystalline Properties of Low Molecular Weight Bis-Chalcone Compounds. Curr Org Synth 2021; 19:463-475. [PMID: 34620065 DOI: 10.2174/1570179418666211006144308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 08/03/2021] [Accepted: 08/16/2021] [Indexed: 11/22/2022]
Abstract
AIMS In this paper, we report on the synthesis and liquid crystalline properties of some low molecular weight bis-chalcone compounds derived from acetone, cyclopentanone and cyclohexanone mesogenic cores. BACKGROUND Structurally bis-chalcones belong to a broader family of chalcone compounds. Chalcone is a compound that consists of two aromatic rings linked by an unsaturated α, β-ketone. OBJECTIVE Liquid crystalline chalcones are prepared by aliphatic chain substituents on two aromatic rings. Chalcones are well studied for their mesomorphic properties. Compared to a large number of chalcone based LCs reported, only a few articles have been published on the mesomorphic properties of bis-chalcone compounds. The target compounds of the present study varied not only in their central core but also in number and position of terminal aliphatic chain substitution-a key structural unit in deciding the liquid crystalline properties of a compound. METHOD All target compounds were synthesized in good yield by base catalyzed Claisen-Schmidt condensation reaction. Molecular structures were confirmed by FT-IR, 1H NMR, 13C NMR, and mass spectroscopic methods. Liquid crystalline property of these compounds was evaluated using polarizing optical microscopy and differential scanning calorimetry. RESULTS Although none of the acetone based compounds exhibited mesomorphism, cyclopentanone and cyclohexanone based compounds with octyloxy chain at para position on either side of the dibenzylidine ring stabilized liquid crystalline smectic (SmA and SmC) and nematic (N) phases. The observed structure-liquid crystalline property relationship was explained by structural analysis of molecules using DFT calculations. Considering the inherent photoluminescence nature of the chalcone moiety, a preliminary study was carried out on a selected compound to reveal its fluorescence property. CONCLUSION Our study brings about an important structure-liquid crystalline property relationship in a relatively unexplored class of bis-chalcone liquid crystals.
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Affiliation(s)
- Anju K Sasidharan
- Department of Chemistry, St. Joseph's College (Autonomous), Devagiri, Kozhikode-673008, Affiliated to University of Calicut, Kerala. India
| | - Jomon Mathew
- Department of Chemistry, St. Joseph's College (Autonomous), Devagiri, Kozhikode-673008, Affiliated to University of Calicut, Kerala. India
| | - Ammathnadu S Achalkumar
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039, Assam. India
| | - Manoj Mathews
- Department of Chemistry, St. Joseph's College (Autonomous), Devagiri, Kozhikode-673008, Affiliated to University of Calicut, Kerala. India
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3
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Huang S, Yu H, Li Q. Supramolecular Chirality Transfer toward Chiral Aggregation: Asymmetric Hierarchical Self-Assembly. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2002132. [PMID: 33898167 PMCID: PMC8061372 DOI: 10.1002/advs.202002132] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 12/21/2020] [Indexed: 05/21/2023]
Abstract
Self-assembly, as a typical bottom-up strategy for the fabrication of functional materials, has been applied to fabricate chiral materials with subtle chiral nanostructures. The chiral nanostructures exhibit great potential in asymmetric catalysis, chiral sensing, chiral electronics, photonics, and even the realization of several biological functions. According to existing studies, the supramolecular chirality transfer process combined with hierarchical self-assembly plays a vital role in the fabrication of multiscale chiral structures. This progress report focuses on the hierarchical self-assembly of chiral or achiral molecules that aggregate with asymmetric spatial structures such as twisted bands, helices, and superhelices in different environments. Herein, recent studies on the chirality transfer induced self-assembly based on a variety of supramolecular interactions are summarized. In addition, the influence of different environments and the states of systems including solutions, condensed states, gel systems, interfaces on the asymmetric hierarchical self-assembly, and the expression of chirality are explored. Moreover, both the driving forces that facilitate chiral bias and the supramolecular interactions that play an important role in the expression, transfer, and amplification of the chiral sense are correspondingly discussed.
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Affiliation(s)
- Shuai Huang
- School of Materials Science and EngineeringKey Laboratory of Polymer Chemistry and Physics of Ministry of EducationPeking UniversityBeijing100871China
- Institute of Advanced MaterialsSchool of Chemistry and Chemical EngineeringSoutheast UniversityNanjingJiangsu Province211189China
| | - Haifeng Yu
- School of Materials Science and EngineeringKey Laboratory of Polymer Chemistry and Physics of Ministry of EducationPeking UniversityBeijing100871China
| | - Quan Li
- Advanced Materials and Liquid Crystal Institute and Chemical Physics Interdisciplinary ProgramKent State UniversityKentOH44242USA
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4
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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: 157] [Impact Index Per Article: 39.3] [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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5
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Zheng ZG, Lu YQ, Li Q. Photoprogrammable Mesogenic Soft Helical Architectures: A Promising Avenue toward Future Chiro-Optics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1905318. [PMID: 32483915 DOI: 10.1002/adma.201905318] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 06/11/2023]
Abstract
Mesogenic soft materials, having single or multiple mesogen moieties per molecule, commonly exhibit typical self-organization characteristics, which promotes the formation of elegant helical superstructures or supramolecular assemblies in chiral environments. Such helical superstructures play key roles in the propagation of circularly polarized light and display optical properties with prominent handedness, that is, chiro-optical properties. The leveraging of light to program the chiro-optical properties of such mesogenic helical soft materials by homogeneously dispersing photosensitive chiral material into an achiral soft system or covalently connecting photochromic moieties to the molecules has attracted considerable attention in terms of materials, properties, and potential applications and has been a thriving topic in both fundamental science and application engineering. State-of-the-art technologies are described in terms of the material design, synthesis, properties, and modulation of photoprogrammable chiro-optical mesogenic soft helical architectures. Additionally, the scientific issues and technical problems that hinder further development of these materials for use in various fields are outlined and discussed. Such photoprogrammable mesogenic soft helical materials are competitive candidates for use in stimulus-controllable chiro-optical devices with high optical efficiency, stable optical properties, and easy miniaturization, facilitating the future integration and systemization of chiro-optical chips in photonics, photochemistry, biomedical engineering, chemical engineering, and beyond.
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Affiliation(s)
- Zhi-Gang Zheng
- Department of Physics, East China University of Science and Technology, Shanghai, 200237, China
| | - Yan-Qing Lu
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, Collaborative Innovation Center of Advanced Microstructures and College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210093, China
| | - Quan Li
- Advanced Materials and Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, OH, 44242, USA
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6
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Kurachkina M, Nádasi H, Alaasar M, Tschierske C, Eremin A. Photomanipulation of the Mechanical Properties in a Liquid Crystal with Azo‐Containing Bent‐Core Mesogens. CHEMPHOTOCHEM 2020. [DOI: 10.1002/cptc.202000125] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | - Hajnalka Nádasi
- Otto von Guericke University Inst. of Physics 39016 Magdeburg Germany
| | - Mohamed Alaasar
- Martin Luther University Halle-Wittenberg Kurt Mothes Str. 2 D-06120 Halle (Saale) Germany
- Department of Chemistry Faculty of Science Cairo University Giza Egypt
| | - Carsten Tschierske
- Martin Luther University Halle-Wittenberg Kurt Mothes Str. 2 D-06120 Halle (Saale) Germany
| | - Alexey Eremin
- Otto von Guericke University Inst. of Physics 39016 Magdeburg Germany
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7
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Lin JD, Wu MH, Jiang SA, Zhang YS, Chen HL, Mo TS, Lee CR. Enantiomorphic double-polymerized chiral polymer composite template for highly efficient energy-saving green window. POLYMER 2020. [DOI: 10.1016/j.polymer.2020.122586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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8
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Turlapati S, B. N. S, Vishwakarma VK, Achalkumar AS, Hegde G. Influence of lateral methyl/chloro substituents on the liquid crystalline and photoswitching behaviour of bent-core mesogens bearing azobenzene wings: synthesis and characterization. NEW J CHEM 2020. [DOI: 10.1039/c9nj06237h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein, we report selectively designed, synthesized and characterized bent-core molecules bearing methyl and chloro substituents at the lateral positions on the phenyl rings of the azobenzene wings for optical storage device applications.
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Affiliation(s)
- Srikanth Turlapati
- Department of Chemistry
- Indian Institute of Technology Guwahati
- Guwahati 781039
- India
| | - Sunil B. N.
- Center for Nano-materials and Displays
- B.M.S. College of Engineering
- Bangalore 560019
- India
- Department of Chemistry
| | | | | | - Gurumurthy Hegde
- Center for Nano-materials and Displays
- B.M.S. College of Engineering
- Bangalore 560019
- India
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9
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de Souza RF, Granado SA, Evangelista LR, Lenzi EK, Li Q, Zola RS. Effect of dynamically changing the substrate's easy axis on the response time of nematic samples. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:505401. [PMID: 30457123 DOI: 10.1088/1361-648x/aaea51] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Recent discoveries of advanced photocontrolled materials have kindled a great deal of interest on their use as command surfaces that switch easy axis under light radiation. One noticeable point when using switchable surfaces on any application is how the dynamical process propagates to the bulk directors. In this paper, we theoretically study the effect of a relaxing easy axis over time on a nematic sample when finite anchoring energy and surface viscosity are included. We first consider the case where just one of the substrates decay over time in an initially distorted director organization. Next, we assume that both substrates can be switched simultaneously. From the calculated director we obtained the optical profile and finally the molecular response time of the material. The response time depends on both the materials and the surfaces properties including its decay time. Our results might be used for understanding and engineering liquid crystal displays and other electro-optical devices with photocontrolled alignment layers.
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Affiliation(s)
- R F de Souza
- Departamento de Física, Universidade Estadual de Maringá, Avenida Colombo, 5790-87020-900 Maringá, Paraná, Brazil
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10
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Bisoyi HK, Bunning TJ, Li Q. Stimuli-Driven Control of the Helical Axis of Self-Organized Soft Helical Superstructures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1706512. [PMID: 29603448 DOI: 10.1002/adma.201706512] [Citation(s) in RCA: 125] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 12/12/2017] [Indexed: 05/22/2023]
Abstract
Supramolecular and macromolecular functional helical superstructures are ubiquitous in nature and display an impressive catalog of intriguing and elegant properties and performances. In materials science, self-organized soft helical superstructures, i.e., cholesteric liquid crystals (CLCs), serve as model systems toward the understanding of morphology- and orientation-dependent properties of supramolecular dynamic helical architectures and their potential for technological applications. Moreover, most of the fascinating device applications of CLCs are primarily determined by different orientations of the helical axis. Here, the control of the helical axis orientation of CLCs and its dynamic switching in two and three dimensions using different external stimuli are summarized. Electric-field-, magnetic-field-, and light-irradiation-driven orientation control and reorientation of the helical axis of CLCs are described and highlighted. Different techniques and strategies developed to achieve a uniform lying helix structure are explored. Helical axis control in recently developed heliconical cholesteric systems is examined. The control of the helical axis orientation in spherical geometries such as microdroplets and microshells fabricated from these enticing photonic fluids is also explored. Future challenges and opportunities in this exciting area involving anisotropic chiral liquids are then discussed.
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Affiliation(s)
- Hari Krishna Bisoyi
- Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, OH, 44242, USA
| | - Timothy J Bunning
- 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, OH, 44242, USA
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11
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Khandelwal H, Timmermans GH, Debije MG, Schenning APHJ. Dual electrically and thermally responsive broadband reflectors based on polymer network stabilized chiral nematic liquid crystals: the role of crosslink density. Chem Commun (Camb) 2018; 52:10109-12. [PMID: 27357239 DOI: 10.1039/c6cc04721a] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A broadband reflector based on a polymer stabilized chiral nematic liquid crystal has been fabricated. The reflection bandwidth can be manually controlled by an electric field and autonomously by temperature.
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Affiliation(s)
- Hitesh Khandelwal
- Functional Organic Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands. and Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - Gilles H Timmermans
- Functional Organic Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands.
| | - Michael G Debije
- Functional Organic Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands.
| | - Albertus P H J Schenning
- Functional Organic Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands. and Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
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12
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Zhao D, Qiu Y, Cheng W, Bi S, Wang H, Wang Q, Liao Y, Peng H, Xie X. Precisely Tuning Helical Twisting Power via Photoisomerization Kinetics of Dopants in Chiral Nematic Liquid Crystals. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:700-708. [PMID: 29268613 DOI: 10.1021/acs.langmuir.7b03786] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
It has been paid much attention to improve the helical twisting power (β) of dopants in chiral nematic liquid crystals (CLCs); however, the correlations between the β value and the molecular structures as well as the interaction with nematic LCs are far from clear. In this work, a series of reversibly photo-switchable axially chiral dopants with different lengths of alkyl or alkoxyl substituent groups have been successfully synthesized through nucleophilic substitution and the thiol-ene click reaction. Then, the effect of miscibility between these dopants and nematic LCs on the β values, as well as the time-dependent decay/growth of the β values upon irradiations, has been investigated. The theoretical Teas solubility parameter shows that the miscibility between dopants and nematic LCs decreases with increasing of the length of substituent groups from dopant 1 to dopant 4. The β value of chiral dopants in nematic LCs decreases from dopant 1 to dopant 4 both at the visible light photostationary state (PSS) and at the UV PSS after UV irradiation. With increasing of the length of substituent groups, the photoisomerization rate constant of dopants increases for trans-cis transformation upon UV irradiation and decreases for the reverse process upon visible light irradiation either in isotropic ethyl acetate or in anisotropic LCs, although the constant in ethyl acetate is several times larger than the corresponding value in LCs. Also, the color of the CLCs could be tuned upon light irradiations. These results enable the precise tuning of the pitch and selective reflection wavelength/color of CLCs, which paves the way to the applications in electro-optic devices, information storage, high-tech anticounterfeit, and so forth.
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Affiliation(s)
| | | | | | - Shuguang Bi
- Hubei Biomass Fibers and Eco-dyeing & Finishing Key Laboratory, College of Chemistry and Chemical Engineering, State Key Laboratory of New Textile Materials and Advanced Processing Technologies, Wuhan Textile University , Wuhan 430073, China
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13
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Mandle RJ. The Shape of Things To Come: The Formation of Modulated Nematic Mesophases at Various Length Scales. Chemistry 2017; 23:8771-8779. [PMID: 28453914 PMCID: PMC5518215 DOI: 10.1002/chem.201701167] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Indexed: 11/22/2022]
Abstract
The twist-bend nematic (NTB ) phase is a recently discovered liquid-crystalline phase that exhibits macroscopic chirality even when formed from achiral materials, and as such presents a unique testbed for studies concerning the spontaneous breaking of mirror symmetry in soft matter. It is primarily exhibited by materials for which the molecular structure is composed of two rigid aromatic units (such as biphenyl connected by a flexible spacer). The local structure of the NTB phase is nematic-like-with molecules having an average orientational order but no positional order-with a nanoscale helix in which the pitch (i.e., the repeat distance of the helix) is of the order of several nanometres. A helix is chiral, and so the bulk NTB phase-in the absence of a biasing chiral environment-spontaneously separates into macroscopic domains of opposite handedness. After discussing the structure of this mesophase and its elucidation, this concept article presents the molecular factors that determine its incidence. The apparent dependency primarily on molecular shape and bend angle rather than particular functional group combinations manifests in this mesophase being exhibited on length scales far beyond those of simple liquid-crystalline dimers, not only in oligomers and polymers, but also in aqueous suspensions of micron sized helical particles.
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14
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Bisoyi HK, Li Q. Light-Driven Liquid Crystalline Materials: From Photo-Induced Phase Transitions and Property Modulations to Applications. Chem Rev 2016; 116:15089-15166. [PMID: 27936632 DOI: 10.1021/acs.chemrev.6b00415] [Citation(s) in RCA: 402] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Light-driven phenomena both in living systems and nonliving materials have enabled truly fascinating and incredible dynamic architectures with terrific forms and functions. Recently, liquid crystalline materials endowed with photoresponsive capability have emerged as enticing systems. In this Review, we focus on the developments of light-driven liquid crystalline materials containing photochromic components over the past decade. Design and synthesis of photochromic liquid crystals (LCs), photoinduced phase transitions in LC, and photoalignment and photoorientation of LCs have been covered. Photomodulation of pitch, polarization, lattice constant and handedness inversion of chiral LCs is discussed. Light-driven phenomena and properties of liquid crystalline polymers, elastomers, and networks have also been analyzed. The applications of photoinduced phase transitions, photoalignment, photomodulation of chiral LCs, and photomobile polymers have been highlighted wherever appropriate. The combination of photochromism, liquid crystallinity, and fabrication techniques has enabled some fascinating functional materials which can be driven by ultraviolet, visible, and infrared light irradiation. Nanoscale particles have been incorporated to widen and diversify the scope of the light-driven liquid crystalline materials. The developed materials possess huge potential for applications in optics, photonics, adaptive materials, nanotechnology, etc. The challenges and opportunities in this area are discussed at the end of the Review.
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Affiliation(s)
- Hari Krishna Bisoyi
- Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University , Kent, Ohio 44242, United States
| | - Quan Li
- Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University , Kent, Ohio 44242, United States
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15
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Mandle RJ. The dependency of twist-bend nematic liquid crystals on molecular structure: a progression from dimers to trimers, oligomers and polymers. SOFT MATTER 2016; 12:7883-7901. [PMID: 27722733 DOI: 10.1039/c6sm01772j] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This article gives an overview on recent developments concerning the twist-bend nematic phase. The twist-bend nematic phase has been discussed as the missing link between the uniaxial nematic mesophase (N) and the helical chiral nematic phase (N*). After an introduction discussing the key physical properties of the NTB phase and the methods used to identify the twist-bend nematic mesophase this review focuses on structure property relationships and molecular features that govern the incidence of this phase.
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Affiliation(s)
- Richard J Mandle
- Department of Chemistry, University of York, York, YO10 5DD, UK.
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16
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Kim DY, Lee SA, Park M, Choi YJ, Kang SW, Jeong KU. Multi-responsible chameleon molecule with chiral naphthyl and azobenzene moieties. SOFT MATTER 2015; 11:2924-2933. [PMID: 25742914 DOI: 10.1039/c5sm00073d] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A photochromic chiral molecule with azobenzene mesogens and a (R)-configuration naphthyl moiety (abbreviated as NCA2M) was specifically designed and synthesized for the demonstration of chameleon-like color changes responding to multitudinous external stimuli, such as temperature, light and electric field. The basic phase transition behaviors of NCA2M were first studied by the combination of differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Based on the structure-sensitive X-ray diffraction results obtained at different temperatures, it was comprehended that the NCA2M molecule exhibited the tilted version of highly ordered smectic crystal phase with 5.45 nm layer thickness. Chiral nematic (N*) liquid crystals (LC) with helical superstructures were formed by doping the NCA2M photochromic chiral molecule in an achiral nematic (N) LC medium. By controlling the helical pitch length of N*-LC with respect to temperature, light and electric field, the wavelength of selectively reflected light from the N* photonic crystal was finely tuned. The light-induced color change of N*-LC film was the most efficient method for covering the whole visible region from blue to green and to red, which allowed us to fabricate remote-controllable photo-responsive devices.
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Affiliation(s)
- Dae-Yoon Kim
- Polymer Materials Fusion Research Center & Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju, Jeonbuk 561-756, Korea.
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Jin O, Fu D, Ge Y, Wei J, Guo J. Hydrogen-bonded chiral molecular switches: photo- and thermally-reversible switchable full range color in the self-organized helical superstructure. NEW J CHEM 2015. [DOI: 10.1039/c4nj01538j] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
New kinds of hydrogen-bonded chiral molecular switches and dual photo/thermo-responsive behavior of self-organized helical superstructure based on them were described.
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Affiliation(s)
- Ouyu Jin
- College of Materials Science and Engineering
- Beijing University of Chemical Technology
- Beijing 100029
- P. R. China
| | - Dengwei Fu
- College of Materials Science and Engineering
- Beijing University of Chemical Technology
- Beijing 100029
- P. R. China
| | - Yixiu Ge
- College of Materials Science and Engineering
- Beijing University of Chemical Technology
- Beijing 100029
- P. R. China
| | - Jie Wei
- College of Materials Science and Engineering
- Beijing University of Chemical Technology
- Beijing 100029
- P. R. China
| | - Jinbao Guo
- College of Materials Science and Engineering
- Beijing University of Chemical Technology
- Beijing 100029
- P. R. China
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18
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Bisoyi HK, Li Q. Light-directing chiral liquid crystal nanostructures: from 1D to 3D. Acc Chem Res 2014; 47:3184-95. [PMID: 25181560 DOI: 10.1021/ar500249k] [Citation(s) in RCA: 209] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Endowing external, remote, and dynamic control to self-organized superstructures with desired functionalities is a principal driving force in the bottom-up nanofabrication of molecular devices. Light-driven chiral molecular switches or motors in liquid crystal (LC) media capable of self-organizing into optically tunable one-dimensional (1D) and three-dimensional (3D) superstructures represent such an elegant system. As a consequence, photoresponsive cholesteric LCs (CLCs), i.e., self-organized 1D helical superstructures, and LC blue phases (BPs), i.e., self-organized 3D periodic cubic lattices, are emerging as a new generation of multifunctional supramolecular 1D and 3D photonic materials in their own right because of their fundamental academic interest and technological significance. These smart stimuli-responsive materials can be facilely fabricated from achiral LC hosts by the addition of a small amount of a light-driven chiral molecular switch or motor. The photoresponsiveness of these materials is a result of both molecular interaction and geometry changes in the chiral molecular switch upon light irradiation. The doped photoresponsive CLCs undergo light-driven pitch modulation and/or helix inversion, which has many applications in color filters, polarizers, all-optical displays, optical lasers, sensors, energy-saving smart devices, and so on. Recently, we have conceptualized and rationally synthesized different light-driven chiral molecular switches that have very high helical twisting powers (HTPs) and exhibit large changes in HTP in different states, thereby enabling wide phototunability of the systems by the addition of very small amounts of the molecular switches into commercially available achiral LCs. The light-driven chiral molecular switches are based on well-recognized azobenzene, dithienylcyclopentene, and spirooxazine derivatives. We have demonstrated high-resolution and lightweight photoaddressable displays without patterned electronics on flexible substrates. The wide tunability of the HTP furnishes reflection colors encompassing the whole visible spectrum and beyond in a reversible manner. Photomodulation of the helical pitch of the CLCs has been achieved by UV, visible, and near-infrared (NIR) light irradiation. NIR-light-induced red, green, and blue (RGB) reflections have been leveraged only by varying the power density of the IR laser. Some chiral switches are found to confer helix inversion to the cholesteric systems, which qualifies the CLCs for applications where circularly polarized light is involved. Dynamic and static primary RGB reflection colors have been achieved in a single film. LC BPs have been fabricated and investigated in the context of self-organized 3D photonic band gap (PBG) materials, and dynamic phototuning of the PBG over the visible region has been achieved. Omnidirectional lasing and tuning of the laser emission wavelength have also been attained in monodisperse photoresponsive CLC microshells fabricated by a capillary-based microfluidic technique. This Account covers the research and development in our laboratory starting from the design concepts and synthesis of photodynamic chiral molecular switches to their applications in the fabrication of photoresponsive CLCs and BPs. Potential and demonstrated practical applications of photoresponsive CLCs, microshells, and BPs are discussed, and the Account concludes with a brief forecast of what lies beyond the horizon in this rapidly expanding and fascinating field.
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Affiliation(s)
- Hari Krishna Bisoyi
- Liquid Crystal
Institute
and Chemical Physics Interdisciplinary Program, Kent State University, Kent, Ohio 44242, United States
| | - Quan Li
- Liquid Crystal
Institute
and Chemical Physics Interdisciplinary Program, Kent State University, Kent, Ohio 44242, United States
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19
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Chien CC, Liu JH. Optical Behaviors of Flexible Photonic Films via the Developed Multiple UV-Exposed Fabrications. Macromol Rapid Commun 2014; 35:1185-90. [DOI: 10.1002/marc.201400009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Revised: 03/03/2014] [Indexed: 12/26/2022]
Affiliation(s)
- Chih-Chieh Chien
- Department of Chemical Engineering; National Cheng Kung University; Tainan 70101 Taiwan
| | - Jui-Hsiang Liu
- Department of Chemical Engineering; National Cheng Kung University; Tainan 70101 Taiwan
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20
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Leuchs S, Lima-Ramos J, Greiner L, Al-Haque N, Tufvesson P, Woodley JM. Reaction Engineering of Biocatalytic Enantioselective Reduction: A Case Study for Aliphatic Ketones. Org Process Res Dev 2013. [DOI: 10.1021/op400117t] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Joana Lima-Ramos
- Center for Process Engineering
and Technology, Department of Chemical and Biochemical Engineering, Technical University of Denmark, DK-2800 Lyngby, Denmark
| | - Lasse Greiner
- Mannheim University of Applied Sciences, Paul-Wittsack-Strasse 10, D-68163
Mannheim, Germany
| | - Naweed Al-Haque
- Center for Process Engineering
and Technology, Department of Chemical and Biochemical Engineering, Technical University of Denmark, DK-2800 Lyngby, Denmark
| | - Pär Tufvesson
- Center for Process Engineering
and Technology, Department of Chemical and Biochemical Engineering, Technical University of Denmark, DK-2800 Lyngby, Denmark
| | - John M. Woodley
- Center for Process Engineering
and Technology, Department of Chemical and Biochemical Engineering, Technical University of Denmark, DK-2800 Lyngby, Denmark
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21
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Leuchs S, Nonnen T, Dechambre D, Na’amnieh S, Greiner L. Continuous biphasic enzymatic reduction of aliphatic ketones. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.molcatb.2012.09.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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22
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Xiang Y, Liu YK, Zhang ZY, You HJ, Xia T, Wang E, Cheng ZD. Observation of the photorefractive effects in bent-core liquid crystals. OPTICS EXPRESS 2013; 21:3434-3444. [PMID: 23481802 DOI: 10.1364/oe.21.003434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We present a new observation of photorefractive (PR) effects in bent-core nematic (BCN) liquid crystal (LC) materials, where two kinds of optical-induced gratings are demonstrated and compared in pure and surface-doped BCN systems. The experimental results showed that these two kinds of gratings exhibit distinctive different polarization-dependent and angular-dependent behaviors, respectively. Furthermore, we supplied the pure and surface-doped rodlike LC systems for comparison, which revealed that V shape molecular structure of BCN can produce charge carrier more efficiently than rodlike molecular structure does. Thus BCN materials can offer an exciting potential for optical information processing.
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Affiliation(s)
- Ying Xiang
- School of Information Engineering, Guangdong University of Technology, Guangzhou 510006, China
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23
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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: 201] [Impact Index Per Article: 16.8] [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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24
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Wang Y, Li Q. Light-driven chiral molecular switches or motors in liquid crystals. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2012; 24:1926-45. [PMID: 22411073 DOI: 10.1002/adma.201200241] [Citation(s) in RCA: 177] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Indexed: 05/05/2023]
Abstract
The ability to tune molecular self-organization with an external stimulus is a main driving force in the bottom-up nanofabrication of molecular devices. Light-driven chiral molecular switches or motors in liquid crystals that are capable of self-organizing into optically tunable helical superstructures undoubtedly represent a striking example, owing to their unique property of selective light reflection and which may lead to applications in the future. In this review, we focus on different classes of light-driven chiral molecular switches or motors in liquid crystal media for the induction and manipulation of photoresponsive cholesteric liquid crystal systems and their consequent applications. Moreover, the change of helical twisting powers of chiral dopants and their capability of helix inversion in the induced cholesteric phases are highlighted and discussed in the light of their molecular geometric changes.
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Affiliation(s)
- Yan Wang
- Liquid Crystal Institute and Chemical Physics, Interdisciplinary Program, Kent State University, Kent, OH 44242, USA
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25
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Gvozdovskyy I, Yaroshchuk O, Serbina M, Yamaguchi R. Photoinduced helical inversion in cholesteric liquid crystal cells with homeotropic anchoring. OPTICS EXPRESS 2012; 20:3499-3508. [PMID: 22418109 DOI: 10.1364/oe.20.003499] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Structural changes caused by the optically induced helical inversion in the cholesteric liquid crystal cells with homeotropic anchoring are studied. In a one-step exposure, a sequence of structural transformations "lying left-handed helix - unwound homeotropic state - lying right-handed helix" is realized. In this process, smooth expansion of a left-handed helix, transition to an unwound state, emergence and smooth compression of a right-handed helix was observed. The unwound state was maintained over a rather wide range of exposures. Well-oriented and highly periodic fingerprint textures capable of the above mentioned structural changes were obtained by rubbing the aligning substrates. This allowed for obtaining photo-tunable diffraction gratings and using them to demonstrate new beam steering principle. Also, pitch reversal suggested new options for optical recording, in particular contrast reversal and edge enhancement.
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Affiliation(s)
- Igor Gvozdovskyy
- Institute of Physics of the National Academy of Sciences of Ukraine, Prospekt Nauki, 46, 03680 Kyiv, Ukraine.
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26
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Jacquart A, Williams RM, Brouwer AM, Ishow E. Decoupling fluorescence and photochromism in bifunctional azo derivatives for bulk emissive structures. Chemistry 2012; 18:3706-20. [PMID: 22322661 DOI: 10.1002/chem.201103411] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2011] [Indexed: 11/08/2022]
Abstract
Bifunctional molecules that combine independent push-pull fluorophores and azo photochromes have been synthesized to create fluorescent structures upon light-induced migration in neat thin films. Their photochromic and emissive properties have been systematically investigated and interpreted in light of those of the corresponding model compounds. Fluorescence lifetimes and photoisomerization and fluorescence quantum yields have been determined in toluene solution. Kinetic analyses of the femtosecond transient absorption spectra reveal that the fluorophores evolve in a few picoseconds into a distorted intramolecular charge-transfer excited state, strongly stabilized in energy. Radiative relaxation to the ground state occurred competitively with the energy-transfer process to the azo moiety. Introduction of a 10 Å-long rigid and nonconjugated bridge between the photoactive units efficiently inhibits the energy transfer while it imparts enhanced free volume, which favors photoactivated molecular migration in the solid state.
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Affiliation(s)
- Aurélie Jacquart
- PPSM-UMR CNRS 8531, ENS Cachan, 61 avenue du Président Wilson, 94235 Cachan cedex, France
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