1
|
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.
Collapse
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
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Kim YG, Park S, Kim SH. Designing photonic microparticles with droplet microfluidics. Chem Commun (Camb) 2022; 58:10303-10328. [PMID: 36043863 DOI: 10.1039/d2cc03629k] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Photonic materials with a periodic change of refractive index show unique optical properties through wavelength-selective diffraction and modulation of the optical density of state, which is promising for various optical applications. In particular, photonic structures have been produced in the format of microparticles using emulsion templates to achieve advanced properties and applications beyond those of a conventional film format. Photonic microparticles can be used as a building block to construct macroscopic photonic materials, and the individual microparticles can serve as miniaturized photonic devices. Droplet microfluidics enables the production of emulsion drops with a controlled size, composition, and configuration that serve as the optimal confining geometry for designing photonic microparticles. This feature article reviews the recent progress and current state of the art in the field of photonic microparticles, covering all aspects of microfluidic production methods, microparticle geometries, optical properties, and applications. Two distinct bottom-up approaches based on colloidal assembly and liquid crystals are, respectively, discussed and compared.
Collapse
Affiliation(s)
- Young Geon Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
| | - Sihun Park
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
| | - Shin-Hyun Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
| |
Collapse
|
4
|
Shi J, Ma C, Ren M, Xu M, Zhu J, Qiu L, Ding Y, Zhang J, Lu H. Stable and tunable single-mode lasers based on cholesteric liquid crystal microdroplets. APPLIED OPTICS 2022; 61:2937-2942. [PMID: 35471268 DOI: 10.1364/ao.456377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 03/12/2022] [Indexed: 06/14/2023]
Abstract
Although many studies on cholesteric liquid crystal (CLC) microdroplet single-mode lasers are available, it has been shown that the stability and tunability of such microdroplets are difficult to achieve simultaneously. In this paper, a new, to the best of our knowledge, method is proposed for the mass and rapid preparation of stable and tunable monodisperse CLC microdroplet single-mode lasers. This is based on the formation of polymer networks on the surface of the microdroplet via interfacial polymerization and a disruption of the orderliness of the polymer networks by increasing the temperature during polymerization, which results in a single pitch inside the microdroplets. This approach enables CLC microdroplet single-mode lasers to achieve improved environmental robustness, while maintaining the same temperature tunability as the unpolymerized sample. Our method has promising future applications in integrated optics, flexible devices, and sensors.
Collapse
|
5
|
Qu R, Li G. Overview of Liquid Crystal Biosensors: From Basic Theory to Advanced Applications. BIOSENSORS 2022; 12:bios12040205. [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] [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.
Collapse
|
6
|
Yang T, Yuan D, Liu W, Zhang Z, Wang K, You Y, Ye H, de Haan LT, Zhang Z, Zhou G. Thermochromic Cholesteric Liquid Crystal Microcapsules with Cellulose Nanocrystals and a Melamine Resin Hybrid Shell. ACS APPLIED MATERIALS & INTERFACES 2022; 14:4588-4597. [PMID: 35038863 DOI: 10.1021/acsami.1c23101] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Thermochromic coatings that can change their color in response to variations in ambient temperature have various potential applications. Cholesteric liquid crystals (CLCs) are promising thermochromic materials due to their selective light reflection and wide regulation range. However, it remains a challenge to fabricate thermochromic coatings that combine good responsivity, mechanical strength, fabrication feasibility, and flexibility. In this study, CLC microcapsules containing cellulose nanocrystals (CNCs) and a melamine-formaldehyde (MF) resin hybrid shell were fabricated via in situ polymerization using CNC-stabilized Pickering emulsions as templates. The CNCs were employed as both Pickering emulsifiers and alignment agents of CLCs to prepare CLC Pickering emulsions. The CLC microcapsules were mixed with curable binders to obtain coating slurries, and thermochromic coatings were prepared by painting the slurries on substrates and drying. The thermochromic coatings could adjust their color in the visible wavelength range in a temperature range of 12 to 42 °C. Moreover, the obtained thermochromic coatings displayed a relatively high reflectance of up to 30-40% and can even be applied to flexible substrates. The CLC microcapsules with CNCs and an MF hybrid shell are promising in the field of smart decorative paints, anti-counterfeit labels, and artificial skins.
Collapse
Affiliation(s)
- Tingjiao Yang
- SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, P. R. 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
| | - Dong Yuan
- SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, P. R. 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
| | - Wei Liu
- SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, P. R. 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
| | - Zhe Zhang
- SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, P. R. 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
| | - Kaiyu Wang
- SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, P. R. 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
| | - Yuxin You
- SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, P. R. 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
| | - Huapeng Ye
- SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, P. R. 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
| | - 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 510006, P. R. 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
| | - Zhen Zhang
- SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, P. R. 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
| | - 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 510006, P. R. 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
| |
Collapse
|
7
|
Fang Y, Fei W, Shen X, Guo J, Wang C. Magneto-sensitive photonic crystal ink for quick printing of smart devices with structural colors. MATERIALS HORIZONS 2021; 8:2079-2087. [PMID: 34846485 DOI: 10.1039/d1mh00577d] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In this paper, we report a facile strategy to combine magneto-responsive photonic crystal (MRPC) ink with 3D printing technology. The building blocks of MRPC are based on Fe3O4 magnetic nanoparticle clusters (MNCs) with uniform and tunable size. The MNC dispersion is able to change its photonic band gap from red to blue as the external magnetic field strength is increased. The magneto-responsive photonic crystal ink can be readily obtained by taking advantage of an ethylene glycol (EG)-in-oil emulsion with a reinforced silicone rubber prepolymer as the outer phase. Using the well-designed formula, the MNC dispersion can be well-preserved inside the emulsion droplets of the ink, maintaining its original contactless magnetic field response. As a proof of concept, custom quick response code and butterfly patterns were successfully printed and showed vivid and tunable color as a function of the external magnetic field strength with good repeatability.
Collapse
Affiliation(s)
- Yiquan Fang
- State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai 200433, P. R. China.
| | | | | | | | | |
Collapse
|
8
|
Qin L, Liu X, He K, Yu G, Yuan H, Xu M, Li F, Yu Y. Geminate labels programmed by two-tone microdroplets combining structural and fluorescent color. Nat Commun 2021; 12:699. [PMID: 33514695 PMCID: PMC7846849 DOI: 10.1038/s41467-021-20908-y] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 12/23/2020] [Indexed: 12/15/2022] Open
Abstract
Creating a security label that carries entirely distinct information in reflective and fluorescent states would enhance anti-counterfeiting levels to deter counterfeits ranging from currencies to pharmaceuticals, but has proven extremely challenging. Efforts to tune the reflection color of luminescent materials by modifying inherent chemical structures remain outweighed by substantial trade-offs in fluorescence properties, and vice versa, which destroys the information integrity of labels in either reflection or fluorescent color. Here, a strategy is reported to design geminate labels by programming fluorescent cholesteric liquid crystal microdroplets (two-tone inks), where the luminescent material is 'coated' with the structural color from helical superstructures. These structurally defined microdroplets fabricated by a capillary microfluidic technique contribute to different but intact messages of both reflective and fluorescent patterns in the geminate labels. Such two-tone inks have enormous potential to provide a platform for encryption and protection of valuable authentic information in anti-counterfeiting technology.
Collapse
Affiliation(s)
- Lang Qin
- Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, P. R. China
| | - Xiaojun Liu
- Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, P. R. China
| | - Kunyun He
- Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, P. R. China
| | - Guodong Yu
- Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, P. R. China
| | - Hang Yuan
- Department of Chemistry and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, P. R. China
| | - Ming Xu
- Department of Chemistry and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, P. R. China
| | - Fuyou Li
- Department of Chemistry and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, P. R. China
| | - Yanlei Yu
- Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, P. R. China.
| |
Collapse
|
9
|
Lin P, Chen H, Li A, Zhuang H, Chen Z, Xie Y, Zhou H, Mo S, Chen Y, Lu X, Cheng Z. Bioinspired Multiple Stimuli-Responsive Optical Microcapsules Enabled by Microfluidics. ACS APPLIED MATERIALS & INTERFACES 2020; 12:46788-46796. [PMID: 32935962 DOI: 10.1021/acsami.0c14698] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Optical microcapsules encapsulating optical materials inside a symmetric spherical confinement are significant elements for the construction of optical units and the integration of optical arrays. However, the multiple stimuli-responsive characteristic of optical microcapsules still remains a challenge due to the insuperable physical barrier between the optical material core and the outside shell and the lack of effective mechanisms to trigger the dynamic switch of the encapsulated optical materials. Inspired by the dual-mode optical modulation of chameleon skins, a novel biomimetic binary optical microcapsule that combines the visible light reflection of chiral nematic liquid crystals and photoluminescence emission of rare-earth complexes is assembled by microfluidic emulsification and interfacial polymerization. The reflected color, fluorescent intensity, and size of the optical microcapsules are facilely controlled in the microfluidic chip by adjusting the composition and flow rate of the injected fluids. Most importantly, the biomimetic binary optical microcapsules demonstrate three reversible responsive behaviors, thermotropic reflection evolution, temperature-dependent fluorescence emission, and Fredericks electro-optical response. The bioinspired multiple stimuli-responsive optical microcapsules enabled by microfluidics provide a templated strategy to manufacture the next generation of intelligent optical units and to achieve the dynamic response of hybrid photonic devices.
Collapse
Affiliation(s)
- Pengcheng Lin
- Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China
| | - Hongbin Chen
- Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China
| | - Ang Li
- Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China
| | - Haoquan Zhuang
- Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China
| | - Zeting Chen
- Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China
| | - Yongji Xie
- Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China
| | - Hanguo Zhou
- Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China
| | - Songping Mo
- Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China
| | - Ying Chen
- Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China
| | - Xiang Lu
- Key Laboratory of Polymer Processing Engineering of the Ministry of Education, National Engineering Research Center of Novel Equipment for Polymer Processing, Guangdong Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, South China University of Technology, Guangzhou 510641, China
| | - Zhengdong Cheng
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843-3122, United States
| |
Collapse
|
10
|
Park S, Lee SS, Kim SH. Photonic Multishells Composed of Cholesteric Liquid Crystals Designed by Controlled Phase Separation in Emulsion Drops. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2002166. [PMID: 32519408 DOI: 10.1002/adma.202002166] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 04/23/2020] [Indexed: 06/11/2023]
Abstract
Cholesteric liquid crystals (CLCs), also known as chiral nematic LCs, show a photonic stopband, which is promising for various optical applications. In particular, CLCs confined in microcompartments are useful for sensing, lasing, and optical barcoding at the microscale. The integration of distinct CLCs into single microstructures can provide advanced functionality. In this work, CLC multishells with multiple stopbands are created by liquid-liquid phase separation (LLPS) in a simple yet highly controlled manner. A homogeneous ternary mixture of LC, hydrophilic liquid, and co-solvent is microfluidically emulsified to form uniform oil-in-water drops, which undergo LLPS to form onion-like drops composed of alternating CLC-rich and CLC-depleted layers. The multiplicity is controlled from one to five by adjusting the initial composition of the ternary mixture, which dictates the number of consecutive steps of LLPS. Interestingly, the concentration of the chiral dopant becomes reduced from the outermost to the innermost CLC drop due to uneven partitioning during LLPS, which results in multiple stopbands. Therefore, the photonic multishells show multiple structural colors. In addition, dye-doped multishells provide band-edge lasing at two different wavelengths. This new class of photonic multishells will provide new opportunities for advanced optical applications.
Collapse
Affiliation(s)
- Sihun Park
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea
| | - Sang Seok Lee
- Functional Composite Materials Research Center, Institute of Advanced Composite Materials, KIST, Wanju-gun, Jeollabuk-do, 55324, South Korea
| | - Shin-Hyun Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea
| |
Collapse
|
11
|
Chi J, Shao C, Zhang Y, Ni D, Kong T, Zhao Y. Magnetically responsive colloidal crystals with angle-independent gradient structural colors in microfluidic droplet arrays. NANOSCALE 2019; 11:12898-12904. [PMID: 31250872 DOI: 10.1039/c9nr04011k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Magnetically responsive colloidal crystal films with gradient structural colors have a significant value in optical applications via controllable external stimuli. Herein, we propose a practical method for fabricating colloidal crystal hydrogel films with continuous gradient structural colors by using superparamagnetic colloidal nanoparticles. The colloidal nanoparticles could self-assemble into chain-like non-close-packed arrays to present structural colors under the stimuli of external magnetic fields. And structural colors with gradient changes could be achieved when subjected to a spatial magnetic field with a remarkable variation in field strength and direction. By integrating with a microfluidic droplet array template with spherical symmetry morphology, we have demonstrated convenient fabrication of free-standing colloidal crystal films with angle-independent gradient structural colors, which could be utilized for the fabrication of optical devices.
Collapse
Affiliation(s)
- Junjie Chi
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, Department of Biomedical Engineering, Shenzhen University, Shenzhen 518060, China. and State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
| | - Changmin Shao
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
| | - Yalan Zhang
- Department of Pharmaceutical Engineering, School of Engineering, China Pharmaceutical University, Nanjing 211198, China
| | - Dong Ni
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, Department of Biomedical Engineering, Shenzhen University, Shenzhen 518060, China.
| | - Tiantian Kong
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, Department of Biomedical Engineering, Shenzhen University, Shenzhen 518060, China.
| | - Yuanjin Zhao
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
| |
Collapse
|
12
|
Lin P, Wei Z, Yan Q, Xie J, Fan Y, Wu M, Chen Y, Cheng Z. Capillary-Based Microfluidic Fabrication of Liquid Metal Microspheres toward Functional Microelectrodes and Photothermal Medium. ACS APPLIED MATERIALS & INTERFACES 2019; 11:25295-25305. [PMID: 31260237 DOI: 10.1021/acsami.9b03007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Liquid metals (LMs) possess tremendous potential applications in flexible electronic devices, heat flow management, and smart actuators. Splitting the bulk LMs into microspheres is of great significance to fabricate free-standing and microscale LM-based functional materials and devices. However, it is difficult to disperse the bulk LMs into microspheres because of their large surface tension and high density. In this work, the capillary-based microfluidic chip is employed to continuously and automatically generate LM microspheres in a large scale. The capillary-based microfluidic fabrication is universally applicable in ionic aqueous solution, hydrophobic solution, and the polymeric aqueous solution. The precise size control of LM microspheres can be easily realized by the co-flowing configuration in the microchannels. The coefficient of size variation of monodispersed LM microspheres can be controlled to as low as 0.47%. The free-standing LM microspheres can be used as functional microelectrodes within a wide temperature range from -19.8 to 20 °C and to fabricate tunable integrated circuits with different output powers. Most importantly, the LM microspheres exhibit photothermal property, which is used to make the optical sensor with linear response and to conduct the solar energy harvesting. The capillary-based microfluidic fabrication of LM microspheres provides a facile and templated methodology for processing bulk LMs into microscale units. The LM microspheres with excellent electrical conductivity and photothermal property hold great promise for the development of miniature soft electronics, light-driven actuators, and energy conversion medium.
Collapse
Affiliation(s)
- Pengcheng Lin
- Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and Energy , Guangdong University of Technology , Guangzhou 510006 , China
| | - Zhan Wei
- Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and Energy , Guangdong University of Technology , Guangzhou 510006 , China
| | - Qi Yan
- Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and Energy , Guangdong University of Technology , Guangzhou 510006 , China
| | - Jiajin Xie
- Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and Energy , Guangdong University of Technology , Guangzhou 510006 , China
| | - Yufeng Fan
- Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and Energy , Guangdong University of Technology , Guangzhou 510006 , China
| | - Minghui Wu
- Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and Energy , Guangdong University of Technology , Guangzhou 510006 , China
| | - Ying Chen
- Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and Energy , Guangdong University of Technology , Guangzhou 510006 , China
| | - Zhengdong Cheng
- Artie McFerrin Department of Chemical Engineering , Texas A&M University , College Station , Texas 77843-3122 , United States
| |
Collapse
|
13
|
Lee SS, Kim SH. Controlled Encapsulation of Cholesteric Liquid Crystals Using Emulsion Templates. Macromol Res 2018. [DOI: 10.1007/s13233-018-6148-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|