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Yang Y, Cui Y, Chen Y, Guo Y, Liu X, Chen X, Liu J, Liu Y, Liu Z. Reflectivity and Angular Anisotropy of Liquid Crystal Microcapsules with Different Particle Sizes by Complex Coalescence. Molecules 2024; 29:3030. [PMID: 38998989 PMCID: PMC11242959 DOI: 10.3390/molecules29133030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 06/14/2024] [Accepted: 06/22/2024] [Indexed: 07/14/2024] Open
Abstract
Cholesteric liquid crystal microcapsules (CLCMs) are used to improve the stability of liquid crystals while ensuring their stimulus response performance and versatility, with representative applications such as sensing, anticounterfeiting, and smart fabrics. However, the reflectivity and angular anisotropy decrease because of the anchoring effect of the polymer shell matrix, and the influence of particle size on this has not been thoroughly studied. In this study, the effect of synthesis technology on microcapsule particle size was investigated using a complex coalescence method, and the effect of particle size on the reflectivity and angular anisotropy of CLCMs was investigated in detail. A particle size of approximately 66 µm with polyvinyl alcohol (PVA, 1:1) exhibited a relative reflectivity of 16.6% and a bandwidth of 20 nm, as well as a narrow particle size distribution of 22 µm. The thermosetting of microcapsules coated with PVA was adjusted and systematically investigated by controlling the mass ratio. The optimized mass ratio of microcapsules (66 µm) to PVA was 2:1, increasing the relative reflectivity from 16.6% (1:1) to 32.0% (2:1) because of both the higher CLCM content and the matching between the birefringence of the gelatin-arabic shell system and PVA. Furthermore, color based on Bragg reflections was observed in the CLCM-coated ortho-axis and blue-shifted off-axis, and this change was correlated with the CLCM particle size. Such materials are promising for anticounterfeiting and color-based applications with bright colors and angular anisotropy in reflection.
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Affiliation(s)
- Yonggang Yang
- School of Printing and Packaging Engineering, Beijing Institute of Graphic Communication, Beijing 102600, China
| | - Yuchen Cui
- School of Printing and Packaging Engineering, Beijing Institute of Graphic Communication, Beijing 102600, China
- Beijing Engineering Research Center of Printed Electronics Institution, Beijing Institute of Graphic Communication, Beijing 102600, China
| | - Yinjie Chen
- School of Printing and Packaging Engineering, Beijing Institute of Graphic Communication, Beijing 102600, China
- Beijing Engineering Research Center of Printed Electronics Institution, Beijing Institute of Graphic Communication, Beijing 102600, China
| | - Yanan Guo
- School of Printing and Packaging Engineering, Beijing Institute of Graphic Communication, Beijing 102600, China
- Beijing Engineering Research Center of Printed Electronics Institution, Beijing Institute of Graphic Communication, Beijing 102600, China
| | - Xiaoqi Liu
- School of Printing and Packaging Engineering, Beijing Institute of Graphic Communication, Beijing 102600, China
- Beijing Engineering Research Center of Printed Electronics Institution, Beijing Institute of Graphic Communication, Beijing 102600, China
| | - Xia Chen
- School of New Media, Beijing Institute of Graphic Communication, Beijing 102600, China
| | - Jianghao Liu
- School of Printing and Packaging Engineering, Beijing Institute of Graphic Communication, Beijing 102600, China
| | - Yu Liu
- School of Printing and Packaging Engineering, Beijing Institute of Graphic Communication, Beijing 102600, China
| | - Zhengfeng Liu
- School of Printing and Packaging Engineering, Beijing Institute of Graphic Communication, Beijing 102600, China
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Zhang Y, Yang H, Chen Y, Yu H. Progress in Fabrication and Applications of Cholesteric Liquid Crystal Microcapsules. Chemistry 2024; 30:e202303198. [PMID: 37971158 DOI: 10.1002/chem.202303198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 11/15/2023] [Accepted: 11/15/2023] [Indexed: 11/19/2023]
Abstract
Liquid crystals (LCs) are well known for inherent responsiveness to external stimuli, such as light, thermal, magnetic, and electric fields. Cholesteric LCs are among the most fascinating, since they possess distinctive optical properties due to the helical molecular orientation. However, the good flow, easy contamination, and poor stability of small-molecule LCs limit their further applications, and microencapsulation as one of the most effective tools can evade these disadvantages. Microencapsulation can offer shell-core structure with LCs in the core can strengthen their stability, avoiding interference with the environment while maintaining the stimuli-responsiveness and optical properties. Here, we report recent progress in the fabrication and applications of cholesteric LC microcapsules (CLCMCs). We summarize general properties and basic principles, fabrication methods including interfacial polymerization, in-situ polymerization, complex coacervation, solvent evaporation, microfluidic and polymerization of reactive mesogens, and then give a comprehensive overview of their applications in various popular domains, including smart fabrics, smart sensor, smart displays, anti-counterfeiting, information encryption, biomedicine and actuators. Finally, we discuss the currently facing challenges and the potential development directions in this field.
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Affiliation(s)
- Yajun Zhang
- College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, 100020, Beijing, China
| | - Haixiao Yang
- College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, 100020, Beijing, China
| | - Yinjie Chen
- Beijing Engineering Research Center of Printed Electronics, Beijing Institute of Graphic Communication, 102600, Beijing, China
| | - Haifeng Yu
- School of Materials Science and Engineering and, Key Laboratory of Polymer Chemistry and, Physics of Ministry of Education, Peking University, 100871, Beijing, China
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Guan Z, Wang L, Bae J. Advances in 4D printing of liquid crystalline elastomers: materials, techniques, and applications. MATERIALS HORIZONS 2022; 9:1825-1849. [PMID: 35504034 DOI: 10.1039/d2mh00232a] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Liquid crystalline elastomers (LCEs) are polymer networks exhibiting anisotropic liquid crystallinity while maintaining elastomeric properties. Owing to diverse polymeric forms and self-alignment molecular behaviors, LCEs have fascinated state-of-the-art efforts in various disciplines other than the traditional low-molar-mass display market. By patterning order to structures, LCEs demonstrate reversible high-speed and large-scale actuations in response to external stimuli, allowing for close integration with 4D printing and architectures of digital devices, which is scarcely observed in homogeneous soft polymer networks. In this review, we collect recent advances in 4D printing of LCEs, with emphases on synthesis and processing methods that enable microscopic changes in the molecular orientation and hence macroscopic changes in the properties of end-use objects. Promising potentials of printed complexes include fields of soft robotics, optics, and biomedical devices. Within this scope, we elucidate the relationships among external stimuli, tailorable morphologies in mesophases of liquid crystals, and programmable topological configurations of printed parts. Lastly, perspectives and potential challenges facing 4D printing of LCEs are discussed.
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Affiliation(s)
- Zhecun Guan
- Department of Nanoengineering, University of California San Diego, La Jolla, CA 92093, USA.
| | - Ling Wang
- School of Materials Science and Engineering, Tianjin University, Tianjin 300350, P. R. China.
| | - Jinhye Bae
- Department of Nanoengineering, University of California San Diego, La Jolla, CA 92093, USA.
- Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093, USA
- Materials Science and Engineering Program, University of California San Diego, La Jolla, CA 92093, USA
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Qu R, Li G. Overview of Liquid Crystal Biosensors: From Basic Theory to Advanced Applications. BIOSENSORS 2022; 12:205. [PMID: 35448265 PMCID: PMC9032088 DOI: 10.3390/bios12040205] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 03/25/2022] [Accepted: 03/26/2022] [Indexed: 05/06/2023]
Abstract
Liquid crystals (LCs), as the remarkable optical materials possessing stimuli-responsive property and optical modulation property simultaneously, have been utilized to fabricate a wide variety of optical devices. Integrating the LCs and receptors together, LC biosensors aimed at detecting various biomolecules have been extensively explored. Compared with the traditional biosensing technologies, the LC biosensors are simple, visualized, and efficient. Owning to the irreplaceable superiorities, the research enthusiasm for the LC biosensors is rapidly rising. As a result, it is necessary to overview the development of the LC biosensors to guide future work. This article reviews the basic theory and advanced applications of LC biosensors. We first discuss different mesophases and geometries employed to fabricate LC biosensors, after which we introduce various detecting mechanisms involved in biomolecular detection. We then focus on diverse detection targets such as proteins, enzymes, nucleic acids, glucose, cholesterol, bile acids, and lipopolysaccharides. For each of these targets, the development history and state-of-the-art work are exhibited in detail. Finally, the current challenges and potential development directions of the LC biosensors are introduced briefly.
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Affiliation(s)
- Ruixiang Qu
- Intelligent Optical Imaging and Sensing Group, Zhejiang Laboratory, Hangzhou 311121, China
| | - Guoqiang Li
- Intelligent Optical Imaging and Sensing Group, Zhejiang Laboratory, Hangzhou 311121, China
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Sheng M, Wang W, Li L, Zhang L, Fu S. All-in-one wearable electronics design: Smart electrochromic liquid-crystal-clad fibers without external electrodes. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.127535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Microencapsulation for Functional Textile Coatings with Emphasis on Biodegradability—A Systematic Review. COATINGS 2021. [DOI: 10.3390/coatings11111371] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The review provides an overview of research findings on microencapsulation for functional textile coatings. Methods for the preparation of microcapsules in textiles include in situ and interfacial polymerization, simple and complex coacervation, molecular inclusion and solvent evaporation from emulsions. Binders play a crucial role in coating formulations. Acrylic and polyurethane binders are commonly used in textile finishing, while organic acids and catalysts can be used for chemical grafting as crosslinkers between microcapsules and cotton fibres. Most of the conventional coating processes can be used for microcapsule-containing coatings, provided that the properties of the microcapsules are appropriate. There are standardised test methods available to evaluate the characteristics and washfastness of coated textiles. Among the functional textiles, the field of environmentally friendly biodegradable textiles with microcapsules is still at an early stage of development. So far, some physicochemical and physical microencapsulation methods using natural polymers or biodegradable synthetic polymers have been applied to produce environmentally friendly antimicrobial, anti-inflammatory or fragranced textiles. Standardised test methods for evaluating the biodegradability of textile materials are available. The stability of biodegradable microcapsules and the durability of coatings during the use and care of textiles still present several challenges that offer many opportunities for further research.
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Sheng M, Li J, Jiang X, Wang C, Li J, Zhang L, Fu S. Biomimetic Solid-Liquid Transition Structural Dye-Doped Liquid Crystal/Phase-Change-Material Microcapsules Designed for Wearable Bistable Electrochromic Fabric. ACS APPLIED MATERIALS & INTERFACES 2021; 13:33282-33290. [PMID: 34227793 DOI: 10.1021/acsami.1c08135] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A novel polymer microcapsule-filled dye-doped liquid crystal (DDLC) and phase-change material (PCM) system inspired by biological materials was first proposed, which was further encapsulated into a calcium alginate substrate by wet spinning for making an electrochromic fiber with both bistable electric-optical capability and knitting characteristics. Results show that the optical appearance of the optimized microcapsules and fiber can be reversibly changed between colored and colorless states according to the electric field by switching the DDLCs between isotropic (I) and anisotropic (A) states. Moreover, both I and A states can remain stable for more than 1 week after removing the electric field, due to the synergy of the greatly increased spatial hindrance of the PCM with core loading of 22.58% and the confinement effect from the polymer microcapsule shell material. Aside from the long-term optical stability, the high content of the densely packed DDLCs also endows the electrochromic fiber with a satisfactory driving voltage of 9.7 V, which is below the human safe voltage, showing great potential in a wide range of applications, such as flexible displays, energy-saving smart windows, and wearable advanced textiles.
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Affiliation(s)
- Mingfei Sheng
- Key Laboratory of Science & Technology of Eco-Textile, Jiangnan University, Ministry of Education, Wuxi, Jiangsu 214122, China
| | - Jingjing Li
- The First Scientific Research Institute of Wuxi, Wuxi, Jiangsu 214122, China
| | - Xiaojun Jiang
- The First Scientific Research Institute of Wuxi, Wuxi, Jiangsu 214122, China
| | - Chengcheng Wang
- Key Laboratory of Science & Technology of Eco-Textile, Jiangnan University, Ministry of Education, Wuxi, Jiangsu 214122, China
| | - Jiashuang Li
- Key Laboratory of Science & Technology of Eco-Textile, Jiangnan University, Ministry of Education, Wuxi, Jiangsu 214122, China
| | - Liping Zhang
- Key Laboratory of Science & Technology of Eco-Textile, Jiangnan University, Ministry of Education, Wuxi, Jiangsu 214122, China
| | - Shaohai Fu
- Key Laboratory of Science & Technology of Eco-Textile, Jiangnan University, Ministry of Education, Wuxi, Jiangsu 214122, China
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