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Ben Salah M, Saadaoui L, Soltani T, Ben Hamadi N, Guesmi A, Maschke U. New Series of Hydrogen-Bonded Liquid Crystal with High Birefringence and Conductivity. Molecules 2024; 29:3422. [PMID: 39065000 PMCID: PMC11279611 DOI: 10.3390/molecules29143422] [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: 03/29/2024] [Revised: 07/18/2024] [Accepted: 07/19/2024] [Indexed: 07/28/2024] Open
Abstract
Liquid crystals with high dielectric anisotropy, low operational thresholds, and significant birefringence (Δn) represent a key focus in soft matter research. This work introduces a novel series of hydrogen-bonded liquid crystals (HBLCs) derived from 4-n-alkoxybenzoic, 4-alkoxy-3-fluorobenzoic derivatives (nOBAF), 4-alkoxy-2,3-fluorobenzoic derivatives (nOBAFF), and 2-fluoro-4-nitrobenzoic acid. The HBLCs were characterized using Fourier transform infrared spectroscopy, and their thermal behavior was evaluated via differential scanning calorimetry. Optical observations were conducted using polarized optical microscopy. The results indicate that mixtures containing benzoic acid with a bilateral fluorine substituent exhibit both SmA and SmC phases, while those with a unilateral fluorine substituent exhibit nematic and SmA phases. Moreover, an increase in the length of the alkoxy chain results in an expanded mesophase temperature range. This study demonstrates that the presence of a fluorine substituent and the incorporation of an NO2 group in the molecular structure result in an increase in dielectric permittivity, DC conductivity, dielectric anisotropy, and birefringence.
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Affiliation(s)
- Manel Ben Salah
- Laboratoire de Physique de la Matière Molle et de la Modélisation Electromagnétique, Faculté des Sciences de Tunis, Université de Tunis El Manar, Tunis 2092, Tunisia; (M.B.S.); (T.S.)
| | - Lotfi Saadaoui
- The MOE Key Laboratory of Weak-Light Nonlinear Photonics and International Sino-Slovenian Joint Research Center on Liquid Crystal Photonics, TEDA Institute of Applied Physics and School of Physics, Nankai University, Tianjin 300457, China
| | - Taoufik Soltani
- Laboratoire de Physique de la Matière Molle et de la Modélisation Electromagnétique, Faculté des Sciences de Tunis, Université de Tunis El Manar, Tunis 2092, Tunisia; (M.B.S.); (T.S.)
| | - Naoufel Ben Hamadi
- Chemistry Department, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), P.O. Box 5701, Riyadh 11432, Saudi Arabia; (N.B.H.); (A.G.)
| | - Ahlem Guesmi
- Chemistry Department, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), P.O. Box 5701, Riyadh 11432, Saudi Arabia; (N.B.H.); (A.G.)
| | - Ulrich Maschke
- Unité Matériaux et Transformations (UMET), UMR 8207–CNRS, University Lille, CNRS, INRAE, Centrale Lille, F-59000 Lille, France
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2
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Gao H, Guo Z, Xue M. A Novel Dinuclear Complex-PLC Composite Material as Fluorescent Switch in Treatment on Osteoarthritis. J Fluoresc 2024:10.1007/s10895-024-03787-6. [PMID: 38861057 DOI: 10.1007/s10895-024-03787-6] [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: 04/18/2024] [Accepted: 06/06/2024] [Indexed: 06/12/2024]
Abstract
In this study, we synthesized a novel Co(II)-containing coordination compound (CP) [Co2(MMBA)2(HPT)2(H2O)2]·2H2O (1) through a solvothermal reaction of Co(NO3)6·6H2O with 3-(pyridin-2-yl)-1 H-1,2,4-triazole (HPT) and 2-(4-methylbenzoyl)benzoic acid (HMMBA). Fluorescence spectroscopy confirmed that this compound exhibited superior blue fluorescence properties compared to the original ligands. Further, aspirin (ASA) was loaded onto this CP via physical adsorption to create CP-ASA. Interestingly, the fluorescence properties of the CP decreased with the loading of the drug but were restored upon drug release. Leveraging the unique optical properties and biocompatibility of Polymer Liquid Crystal (PLC), we further encapsulated CP-ASA, forming the CP-PLC@ASA composite. The target product was confirmed through various characterization techniques including Elemental Analysis (EA), Fourier-Transform Infrared Spectroscopy (FT-IR), Powder X-Ray Diffraction (PXRD), and Thermogravimetric Analysis (TGA). Moreover, the biological activity of this composite was evaluated in vitro for osteoarthritis, and its potential mechanisms were explored.
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Affiliation(s)
- Huayi Gao
- Department of Cerebrovascular Diseases, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
- Department of Orthopaedics, Chinese People's Liberation Army (PLA) General Hospital, Chinese PLA Medical School, Beijing, China
| | - Zheng Guo
- Department of Orthopaedics, Chinese People's Liberation Army (PLA) General Hospital, Chinese PLA Medical School, Beijing, China
| | - Mengzhou Xue
- Department of Cerebrovascular Diseases, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
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3
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Ma C, Zhang Z, Yang Y, Wang P, Yu M, Gao Y, Wang Q, Xiao J, Zou C, Yang H. A Smart Window with Passive Radiative Cooling and Switchable Near-Infrared Light Transmittance via Molecular Engineering. ACS APPLIED MATERIALS & INTERFACES 2024. [PMID: 38711173 DOI: 10.1021/acsami.4c02819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Smart windows with synergetic light modulation have heightened demands for applications in smart cars and novel buildings. However, improving the on-demand energy-saving efficiency is quite challenging due to the difficulty of modulating sunlight with a broad bandwidth in an energy-saving way. Herein, a smart window with switchable near-infrared light transmittance and passive radiative cooling is prepared via a monomer design strategy and photoinduced polymerization. The effects of hydrogen bonds and fluorine groups in acrylate monomers on the electro-optical properties as well as microstructures of polymer-dispersed liquid crystal films have been systematically studied. Some films show a high contrast ratio of 90.4 or a low threshold voltage (Vth) of 2.0 V, which can be roll-to-roll processed in a large area. Besides, the film has a superior indoor temperature regulation ability due to its passive radiative cooling and controllable near-infrared light transmittance properties. Its radiative cooling efficiency is calculated to be 142.69 W/m2 and NIR transmittance could be switched to below 10%. The introduction of a carboxylic monomer and fluorinated monomer into the system endows the film with a highly efficient temperature management capability. The film has great potential for applications in fields such as flexible smart windows, camouflage materials, and so on.
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Affiliation(s)
- Cong Ma
- School of Materials Science and Engineering, Peking University, Beijing 100083, China
| | - Zuowei Zhang
- Beijing Advanced Innovation Center for Materials Genome Engineering, Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China
| | - Yihai Yang
- School of Materials Science and Engineering, Peking University, Beijing 100083, China
| | - Peixiang Wang
- Yantai Xianhua Technology Group Co., Ltd, Yantai 264006, China
| | - Meina Yu
- Beijing Advanced Innovation Center for Materials Genome Engineering, Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China
| | - Yanzi Gao
- Beijing Advanced Innovation Center for Materials Genome Engineering, Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China
| | - Qian Wang
- Beijing Advanced Innovation Center for Materials Genome Engineering, Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China
| | - Jiumei Xiao
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Cheng Zou
- Beijing Advanced Innovation Center for Materials Genome Engineering, Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China
| | - Huai Yang
- School of Materials Science and Engineering, Peking University, Beijing 100083, China
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4
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Lin H, Zhao Y, Jiao X, Gao H, Guo Z, Wang D, Luan Y, Wang L. Preparation and Application of Polymer-Dispersed Liquid Crystal Film with Step-Driven Display Capability. Molecules 2024; 29:1109. [PMID: 38474621 DOI: 10.3390/molecules29051109] [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: 02/01/2024] [Revised: 02/22/2024] [Accepted: 02/27/2024] [Indexed: 03/14/2024] Open
Abstract
The realization of multifunctional advanced displays with better electro-optical properties is especially crucial at present. However, conventional integral full drive-based transparent display is increasingly failing to meet the demands of the day. Herein, partitioned polymerization as a novel preparation method was introduced innovatively into polymer-dispersed liquid crystals (PDLC) for realizing a step-driven display in agreement with fluorescent dye to solve the above drawback. At first, the utilization of fluorescent dye to endow the PDLC film with fluorescent properties resulted in a reduction in the saturation voltage of the PDLC from 39.7 V to 25.5 V and an increase in the contrast ratio from 58.4 to 96.6. Meanwhile, the experimental observations and theoretical considerations have elucidated that variation in microscopic pore size can significantly influence the electro-optical behavior of PDLC. Then, the step-driven PDLC film was fabricated through the exposure of different regions of the LC cell to different UV-light intensities, resulting in stepwise voltage-transmittance (V-T) responses of the PDLC film for the corresponding regions. Consequently, under appropriate driving voltages, the PDLC can realize three different states of total scattering, semi-transparent and total transparent, respectively. In addition, the PDLC film also embodied an outstanding anti-aging property and UV-shielding performance, which makes it fascinating for multifunctional advanced display applications.
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Affiliation(s)
- Hui Lin
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
- Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yuzhen Zhao
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
| | - Xiangke Jiao
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
| | - Hong Gao
- Division of Material Engineering, China Academy of Space Technology, Beijing 100094, China
| | - Zhun Guo
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
| | - Dong Wang
- Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yi Luan
- Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Lei Wang
- Key Laboratory of Chemical Additives for China National Light Industry, Shaanxi Key Laboratory of Chemical Additives for Industry, College of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi'an 710021, China
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Yu M, He X, Qin J, Hu Y, Wang Q, Zou C, Wei H, Wang X, Gao Y, Yang H. Impact of crosslinking agents with steric cyclic groups on the properties of polymer-dispersed liquid crystals. Phys Chem Chem Phys 2024; 26:7388-7397. [PMID: 38351835 DOI: 10.1039/d3cp05683j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
As a type of intelligent dimming film, polymer-dispersed liquid crystals (PDLCs) have been widely applied in various fields, such as smart windows, light shutters and displays. The properties of PDLCs are greatly influenced by the structure of the raw materials. In this work, the impact of crosslinking agents with different cyclic or chain groups was investigated by comparing the electro-optical performance and the morphology of the polymer matrix in the as-made PDLC films. It was found that the incorporation of large steric groups into the crosslinking agents can alter the morphology of the polymer matrix and thus affect the electro-optical properties. However, the impact is distinct when the spatial structure or rigidity is different. Besides, a combination of crosslinking agents with flexible alkyl-chain structures and steric structures can further reduce the threshold voltage while keeping the high contrast ratio. After detailed comparison, an optimized combination of BDDA/TCDDA in a weight ratio of 1/1 is selected to demonstrate the enhanced properties of the as-constructed film with a thickness of 20 μm. It exhibits low threshold voltage (8.2 V), low saturation voltage (21.2 V) and a high contrast ratio (203) simultaneously. This research offers an optimizing method from the crosslinking agent perspective and is anticipated to promote the further improvement of the PDLC's performance.
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Affiliation(s)
- Meina Yu
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China.
| | - Xian He
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China.
| | - Jing Qin
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China.
| | - Yongchuan Hu
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China.
| | - Qian Wang
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China.
| | - Cheng Zou
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China.
- Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing, China
| | - Huiyun Wei
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Xiao Wang
- School of Materials Science and Engineering, Peking University, Beijing 100871, China.
| | - Yanzi Gao
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China.
| | - Huai Yang
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China.
- Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing, China
- School of Materials Science and Engineering, Peking University, Beijing 100871, China.
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6
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Wu Y, Zhao Y, Wang D. Preparation of Progressive Driving Bilayer Polymer-Dispersed Liquid Crystals Possessing a PDLC-PVA-PDLC Structure. Molecules 2024; 29:508. [PMID: 38276586 PMCID: PMC10819776 DOI: 10.3390/molecules29020508] [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: 12/29/2023] [Revised: 01/15/2024] [Accepted: 01/17/2024] [Indexed: 01/27/2024] Open
Abstract
In this paper, the bilayer polymer-dispersed liquid crystals possessing a PDLC-PVA-PDLC structure were prepared by integrating two monolayer PDLCs. The effect of the polymer mesh size on the electro-optical properties of a bilayer PDLC was investigated by comparing the micro-morphology and electro-optical curves under different polymerization conditions. In addition, the impact of doping MoO2 nanoparticles with surface modification on the comprehensive performance of the bilayer PDLC was further researched. The contrast ratio of the bilayer PDLC prepared under the optimal conditions was improved by more than 90% and still maintained excellent progressive driving performance. Therefore, the development of a bilayer PDLC with optimal electro-optical properties will significantly enhance the technological prospects for the application of PDLC-based devices in smart windows, displays, and flexible devices.
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Affiliation(s)
- Yongle Wu
- Xi’an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi’an 710123, China; (Y.W.); (Y.Z.)
- Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yuzhen Zhao
- Xi’an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi’an 710123, China; (Y.W.); (Y.Z.)
| | - Dong Wang
- Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
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7
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Lim S, Ahn HS, Jang EJ, Boo SY, Gasonoo A, Gwag JS, Lee JH, Choi Y. Polymer Dispersed Liquid Crystal Imprinted by Microlens Array for Enhanced Outcoupling Efficiency of Organic Light Emitting Diode. Molecules 2023; 29:73. [PMID: 38202660 PMCID: PMC10779693 DOI: 10.3390/molecules29010073] [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: 11/15/2023] [Revised: 12/19/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024] Open
Abstract
In this paper, we demonstrate the use of polymer dispersed liquid crystal (PDLC) imprinted with a microlens array (MLA) via solution process to improve the outcoupling efficiency of organic light emitting diodes (OLEDs). The PDLC, well known for its scattering effect, is an excellent technology for improving the outcoupling efficiency of OLEDs. Additionally, we introduce a simple spin-coating process to fabricate PDLC which is adaptable for future solution-processed OLEDs. The MLA-imprinted PDLC applied OLED shows an enhancement factor of 1.22 in outcoupling efficiency which is a 37.5% increase compared to the existing PDLC techniques without changing the electrical properties of the OLED. Through this approach, we can expect the roll-to-roll based extremely flexible OLED, and with further research on pattering PDLC by various templates, higher outcoupling efficiency is achievable through a simple UV irradiation process.
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Affiliation(s)
- Seongmin Lim
- Department of Electronic Engineering, Hanbat National University, Daejeon 34158, Republic of Korea; (S.L.); (H.-S.A.); (E.-J.J.)
| | - Hyeon-Sik Ahn
- Department of Electronic Engineering, Hanbat National University, Daejeon 34158, Republic of Korea; (S.L.); (H.-S.A.); (E.-J.J.)
| | - Eun-Jeong Jang
- Department of Electronic Engineering, Hanbat National University, Daejeon 34158, Republic of Korea; (S.L.); (H.-S.A.); (E.-J.J.)
| | - So-Young Boo
- Department of Creative Convergence Engineering, Hanbat National University, Daejeon 34158, Republic of Korea; (S.-Y.B.); (J.-H.L.)
| | - Akpeko Gasonoo
- Department of Chemistry, University of Calgary, Calgary, AB T2N 1N4, Canada;
| | - Jin-Seog Gwag
- Department of Physics, Yeungnam University, Gyeongsan 38541, Republic of Korea;
| | - Jae-Hyun Lee
- Department of Creative Convergence Engineering, Hanbat National University, Daejeon 34158, Republic of Korea; (S.-Y.B.); (J.-H.L.)
| | - Yoonseuk Choi
- Department of Electronic Engineering, Hanbat National University, Daejeon 34158, Republic of Korea; (S.L.); (H.-S.A.); (E.-J.J.)
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8
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He X, Zhang Z, Zhou F, Hu Y, Zou C, Gao Y, Wang Q, Yu M, Yang H. Study on the Effect of α-Substituted Acrylate Monomers on the Electro-Optical Properties of Polymer-Dispersed Liquid Crystal Films. ACS APPLIED MATERIALS & INTERFACES 2023; 15:58861-58872. [PMID: 38059631 DOI: 10.1021/acsami.3c13382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
Polymer-dispersed liquid crystals (PDLCs) show great application potential in the areas of displays and smart windows. However, their electro-optical (E-O) properties such as contrast ratio and threshold voltage still need further improvement. In this study, the effects of α-substituted acrylate monomers on the morphology and E-O properties of PDLC composite films were systematically studied. It was found that the large substituent tended to increase the void size of the polymer matrix, while the small fluorine substitution led to a microsphere-type polymer morphology, which deteriorated the E-O performance. Finally, a largely improved E-O performance of low threshold voltage (0.437 V/μm), low saturation voltage (1.012 V/μm), and high contrast ratio (27) was achieved in an 8 μm-thick film by the addition of a chlorine-substituted monomer. This study provides a new approach for optimizing PDLCs from a material perspective.
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Affiliation(s)
- Xian He
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, P. R. China
| | - Zuowei Zhang
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, P. R. China
| | - Foxin Zhou
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, P. R. China
| | - Yongchuan Hu
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, P. R. China
| | - Cheng Zou
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, P. R. China
- Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, P. R. China
| | - Yanzi Gao
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, P. R. China
| | - Qian Wang
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, P. R. China
| | - Meina Yu
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, P. R. China
| | - Huai Yang
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, P. R. China
- Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, P. R. China
- School of Materials Science and Engineering, Peking University, No. 5 Yiheyuan Road, Haidian District, Beijing 100871, P. R. China
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9
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Ma J, Choi J, Park S, Kong I, Kim D, Lee C, Youn Y, Hwang M, Oh S, Hong W, Kim W. Liquid Crystals for Advanced Smart Devices with Microwave and Millimeter-Wave Applications: Recent Progress for Next-Generation Communications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2302474. [PMID: 37225649 DOI: 10.1002/adma.202302474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/22/2023] [Indexed: 05/26/2023]
Abstract
Liquid crystals (LCs) technology have a well-established history of applications in visible light, particularly in the display industry. However, with the rapid growth in communication technology, LCs have become a topic of current interest for high-frequency microwave (MW) and millimeter-wave (mmWave) applications due to promising characteristics such as tunability, continuous tuning, low losses, and price compatibility. To improve the performance of future communication technology using LCs, it is not sufficient only with the perspective of radio-frequency (RF) technology. Therefore, it is imperative to understand not only the novel structural designs and optimization of MW engineering but also the perspective of materials engineering when implementing advanced RF devices with maximum performance for next-generation satellite and terrestrial communication. Herein, based on advanced nematic LCs, polymer-modified LCs, dual-frequency LCs, and photo-reactive LCs, this article summarizes and examines the modulation principles and key research directions for the design strategies of LCs for advanced smart RF devices with improved driving performance and novel functionality. Furthermore, the challenges in development of state-of-the-art smart RF devices that use LCs are discussed.
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Affiliation(s)
- Junseok Ma
- Laboratory of Wave-Arrays and Display Engineering (WADE Group), Department of Electrical Electronics Engineering, POSTECH, Pohang, 37673, Republic of Korea
| | - Jinyoung Choi
- Laboratory of Wave-Arrays and Display Engineering (WADE Group), Department of Electrical Electronics Engineering, POSTECH, Pohang, 37673, Republic of Korea
| | - Sungeun Park
- Laboratory of Wave-Arrays and Display Engineering (WADE Group), Department of Electrical Electronics Engineering, POSTECH, Pohang, 37673, Republic of Korea
| | - Imbo Kong
- Laboratory of Wave-Arrays and Display Engineering (WADE Group), Department of Electrical Electronics Engineering, POSTECH, Pohang, 37673, Republic of Korea
| | - Daehyeon Kim
- Laboratory of Microwave Antenna, Device and System (MADs Group), Department of Electrical Electronics Engineering, POSTECH, Pohang, 37673, Republic of Korea
| | - Cheonga Lee
- Laboratory of Microwave Antenna, Device and System (MADs Group), Department of Electrical Electronics Engineering, POSTECH, Pohang, 37673, Republic of Korea
| | - Youngno Youn
- Laboratory of Microwave Antenna, Device and System (MADs Group), Department of Electrical Electronics Engineering, POSTECH, Pohang, 37673, Republic of Korea
| | - Myeonggin Hwang
- Laboratory of Microwave Antenna, Device and System (MADs Group), Department of Electrical Electronics Engineering, POSTECH, Pohang, 37673, Republic of Korea
| | - Seungwon Oh
- Laboratory of Liquid Crystal Photonics (LCP Group), Department of Electrical Information Communication Engineering, Kangwon National University, Samcheok, 25913, Republic of Korea
| | - Wonbin Hong
- Laboratory of Microwave Antenna, Device and System (MADs Group), Department of Electrical Electronics Engineering, POSTECH, Pohang, 37673, Republic of Korea
| | - Wooksung Kim
- Laboratory of Wave-Arrays and Display Engineering (WADE Group), Department of Electrical Electronics Engineering, POSTECH, Pohang, 37673, Republic of Korea
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10
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Ghosh S, Abraham E, Smalyukh II. Low-Voltage Haze Tuning with Cellulose-Network Liquid Crystal Gels. ACS NANO 2023; 17:19767-19778. [PMID: 37725591 DOI: 10.1021/acsnano.3c03693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
Being key components of the building envelope, glazing products with tunable optical properties are in great demand because of their potential for boosting energy efficiency and privacy features while enabling the main function of allowing natural light indoors. However, windows and skylights with electric switching of haze and transparency are rare and often require high voltages or electric currents, as well as not fully meet the stringent technical requirements for glazing applications. Here, by introducing a predesigned gel material we describe an approach dubbed "Haze-Switch" that involves low-voltage tuning of the haze coefficient in a broad range of 2-90% while maintaining high visible-range optical transmittance. The approach is based on a nanocellulose fiber gel network infiltrated by a nematic liquid crystal, which can be switched between polydomain and monodomain spatial patterns of optical axis via a dielectric coupling between the nematic domains and the applied external electric field. By utilizing a nanocellulose network of nanofibers ∼10 nm in diameter we achieve <10 V dielectric switching and <2% haze in the clear state, as needed for applications in window products. We characterize physical properties relevant to window and smart glass technologies, like the color rendering index, haze coefficient, and switching times, demonstrating that our material and envisaged products can meet the stringent requirements of the glass industry, including applications such as privacy windows, skylights, sunroofs, and daylighting.
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Affiliation(s)
- Souvik Ghosh
- Department of Physics, University of Colorado, Boulder, Colorado 80309, United States
| | - Eldho Abraham
- Department of Physics, University of Colorado, Boulder, Colorado 80309, United States
| | - Ivan I Smalyukh
- Department of Physics, University of Colorado, Boulder, Colorado 80309, United States
- International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM2), Hiroshima University, Boulder, Higashihiroshima 739-8526, Japan
- Renewable and Sustainable Energy Institute, National Renewable Energy Laboratory and University of Colorado, Boulder, Colorado 80309, United States
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11
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Kim K, Kim SU, Choi MY, Saeed MH, Kim Y, Na JH. Voxelated opto-physically unclonable functions via irreplicable wrinkles. LIGHT, SCIENCE & APPLICATIONS 2023; 12:245. [PMID: 37788994 PMCID: PMC10547705 DOI: 10.1038/s41377-023-01285-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 08/30/2023] [Accepted: 09/07/2023] [Indexed: 10/05/2023]
Abstract
The increased prevalence of the Internet of Things (IoT) and the integration of digital technology into our daily lives have given rise to heightened security risks and the need for more robust security measures. In response to these challenges, physical unclonable functions (PUFs) have emerged as promising solution, offering a highly secure method to generate unpredictable and unique random digital values by leveraging inherent physical characteristics. However, traditional PUFs implementations often require complex hardware and circuitry, which can add to the cost and complexity of the system. We present a novel approach using a random wrinkles PUF (rw-PUF) based on an optically anisotropic, facile, simple, and cost-effective material. These wrinkles contain randomly oriented liquid crystal molecules, resulting in a two-dimensional retardation map corresponding to a complex birefringence pattern. Additionally, our proposed technique allows for customization based on specific requirements using a spatial light modulator, enabling fast fabrication. The random wrinkles PUF has the capability to store multiple data sets within a single PUF without the need for physical alterations. Furthermore, we introduce a concept called 'polyhedron authentication,' which utilizes three-dimensional information storage in a voxelated random wrinkles PUF. This approach demonstrates the feasibility of implementing high-level security technology by leveraging the unique properties of the rw-PUF.
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Affiliation(s)
- Kitae Kim
- Department of Convergence System Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 34134, Republic of Korea
| | - Se-Um Kim
- Department of Electrical and Information Engineering, Seoul National University of Science & Technology, 232 Gongneung-ro, Nowon-gu, Seoul, 01811, Republic of Korea
| | - Moon-Young Choi
- Department of Convergence System Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 34134, Republic of Korea
| | - Mohsin Hassan Saeed
- Department of Electrical, Electronics, and Communication Engineering Education, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 34134, Republic of Korea
| | - Youngmin Kim
- Hologram Research Center, Korea Electronics Technology Institute, World Cup buk-ro 54-gil, Mapo-gu, Seoul, 03924, Republic of Korea
| | - Jun-Hee Na
- Department of Convergence System Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 34134, Republic of Korea.
- Department of Electrical, Electronics, and Communication Engineering Education, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 34134, Republic of Korea.
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12
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Bouriche A, Alachaher-Bedjaoui L, Barrera A, Staelens JN, Maschke U. Thermal Degradation Studies of Poly(2-ethyl hexyl acrylate) in the Presence of Nematic Liquid Crystals. Polymers (Basel) 2023; 15:3934. [PMID: 37835983 PMCID: PMC10575342 DOI: 10.3390/polym15193934] [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: 07/28/2023] [Revised: 09/20/2023] [Accepted: 09/22/2023] [Indexed: 10/15/2023] Open
Abstract
The thermal degradation behavior of Poly(2-ethyl hexyl hcrylate) (Poly(2-EHA)), blended with a commercially available nematic liquid crystal (LC) mixture, was investigated by thermal gravimetric analysis (TGA). Different heating rates, ranging from 5 to 200 °C/min, were applied under an inert atmosphere. Based on the TGA results, activation energies (Eα) at different conversion rates (α) were determined using three integral isoconversion methods: Flynn-Wall-Ozawa (FWO), Tang, and Kissinger-Akahira-Sunose (KAS). It can be noticed that the global evolution of these activation energies was the same for the three models. The coefficient of determination R2 presented values generally higher than 0.97. Using these models, the Eα value for the LC remains constant at 64 kJ/mol for all conversions rates. For the polymer Poly(2-EHA), applying the Tang and FWO models, the activation energy presents a variation ranging from 80 kJ/mol, for conversion α = 0.1, to 170 kJ/mol, for α = 0.9. For the third model (KAS), this energy varies between 80 and 220 kJ/mol in the same range of α.
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Affiliation(s)
- Amina Bouriche
- Laboratoire de Recherche sur les Macromolécules (LRM), Faculté des Sciences, Université AbouBekr Belkaïd de Tlemcen (UABB), BP 119, Tlemcen 13000, Algeria
- Unité Matériaux et Transformations (UMET), UMR 8207, Université Lille, CNRS, INRAE, Centrale Lille, 59000 Lille, France
| | - Lamia Alachaher-Bedjaoui
- Laboratoire de Recherche sur les Macromolécules (LRM), Faculté des Sciences, Université AbouBekr Belkaïd de Tlemcen (UABB), BP 119, Tlemcen 13000, Algeria
| | - Ana Barrera
- Unité Matériaux et Transformations (UMET), UMR 8207, Université Lille, CNRS, INRAE, Centrale Lille, 59000 Lille, France
| | - Jean-Noël Staelens
- Unité Matériaux et Transformations (UMET), UMR 8207, Université Lille, CNRS, INRAE, Centrale Lille, 59000 Lille, France
| | - Ulrich Maschke
- Unité Matériaux et Transformations (UMET), UMR 8207, Université Lille, CNRS, INRAE, Centrale Lille, 59000 Lille, France
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13
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Yu M, Xu J, Zhang L, Wang Q, Zou C, Gao Y, Yang H. Balanced electro-optical properties and off-axis haze performance of a polymer-dispersed liquid crystal film via refractive index matching. Phys Chem Chem Phys 2023; 25:23770-23782. [PMID: 37622171 DOI: 10.1039/d3cp03024e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
As a type of smart dimming film, polymer-dispersed liquid crystals (PDLCs) show great prospects in the fields of indoor partition, electronic curtains, and automobile windows. However, its high off-axis haze greatly impacts the application scope. This obvious shortcoming is mainly caused by the serious mismatch between the effective refractive index of the liquid crystal (neff) and the refractive index of the polymer matrix (np) at large viewing angles. Thereby, factors affecting the viewing angle of a PDLC film are analyzed in this research, including the birefringence of the liquid crystal (Δn), film thickness, and the refractive index of the polymer matrix (np). Balanced electro-optical properties are guaranteed simultaneously. It is found that high on-state transmittance and low off-axis haze can be achieved at large viewing angles in the suggested optimized case where Δn is within the range of 0.1-0.13; the film thickness is between 20 μm and 15 μm; and np approaches no but the difference does not exceed 0.03.
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Affiliation(s)
- Meina Yu
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, China.
| | - Jianjun Xu
- Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, China
| | - Luoning Zhang
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, China.
| | - Qian Wang
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, China.
| | - Cheng Zou
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, China.
- Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yanzi Gao
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, China.
| | - Huai Yang
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, China.
- Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
- School of Materials Science and Engineering, Peking University, Beijing, China
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14
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Hadjichristov GB. Control of Coherent Light through Microperiodic Director Modulation in Nematic Films under Low-Voltage DC Electric Field. MATERIALS (BASEL, SWITZERLAND) 2023; 16:6014. [PMID: 37687708 PMCID: PMC10488426 DOI: 10.3390/ma16176014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 08/12/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023]
Abstract
This work addresses the achievement of efficient control of laser light transmission through stationary microperiodic parallel stripe textures formed in films of nematic liquid crystals (NLCs) in planar-oriented cells upon a direct-current (DC) electric field. By varying the field intensity and, thereby, the field-induced periodic modulation of the nematic director and hence the complex transmittance function corresponding to the longitudinal domain texture induced in NLC films with initial planar alignment, the intensity of a linearly polarized laser beam passed through the films can be well controlled. In 25 µm-thick films of room-temperature NLCs pentylcyanobiphenyl (5CB), this results in a low-voltage (~4 V) sharp and deep V-shaped behavior of their electro-optically controlled transmittance. Such a reversible electro-optical effect is interesting for active control of laser beam intensity and other applications. The relevant physical mechanism is analyzed and explained.
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Affiliation(s)
- Georgi B Hadjichristov
- Laboratory of Optics and Spectroscopy, Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia, Bulgaria
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15
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Zhao Y, Li C, Lang T, Sun Y, Li Q, Shi X, Yao R, Zhang H, Zhao Y. Fluorescent Dye-Doped Brightening Polymer-Stabilized Bistable Cholesteric Liquid Crystal Films. Molecules 2023; 28:molecules28083509. [PMID: 37110743 PMCID: PMC10144587 DOI: 10.3390/molecules28083509] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 04/12/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
Brightening polymer-stabilized bistable cholesteric liquid crystal (PSBCLC) films with doped fluorescent dyes were prepared using the polymerization-induced phase separation (PIPS) method. The transmittance performance behavior of these films in both states (focal conic and planar) and absorbance change in multiple dye concentrations were studied using a UV/VIS/NIR spectrophotometer. The change occurring in dye dispersion morphology with different concentrations was obtained by means of the polarizing optical microscope. The maximum fluorescence intensity of different dye-doped PSBCLC films was measured using a fluorescence spectrophotometer. Moreover, the contrast ratios and driving voltages of these films were calculated and recorded to demonstrate film performance. Finally, the optimal concentration of dye-doped PSBCLC films with a high contrast ratio and a relatively low drive voltage was found. This is expected to have great potential applications in cholesteric liquid crystal reflective displays.
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Affiliation(s)
- Yuzhen Zhao
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
| | - Chaonian Li
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
| | - Tingting Lang
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
| | - Yitian Sun
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
| | - Qingbo Li
- Shandong Lanbeisite Educational Equipment Group Co., Ltd., Jinan 250100, China
| | - Xinli Shi
- Shandong Lanbeisite Educational Equipment Group Co., Ltd., Jinan 250100, China
| | - Ruijuan Yao
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
| | - Huimin Zhang
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
| | - Yang Zhao
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
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16
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Xian H, Li L, Ding Y, Chu M, Ye C. Preparation and Orthogonal Analysis for Dual-Responsive Electrochromic Polymer Dispersed Liquid Crystal Devices. Polymers (Basel) 2023; 15:polym15081860. [PMID: 37112007 PMCID: PMC10144608 DOI: 10.3390/polym15081860] [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: 02/25/2023] [Revised: 03/23/2023] [Accepted: 04/07/2023] [Indexed: 04/29/2023] Open
Abstract
In this work, we provide a fabrication method for dual-responsive electrochromic (EC) polymer dispersed liquid crystal (PDLC) devices. The EC PDLC device was developed by combing the PDLC technique and a colored complex formed via a redox reaction without a specific EC molecule in a simple preparation method. The mesogen played dual roles in the device for scattering in the form of microdroplets and participating in the redox reactions. Orthogonal experiments were performed with the acrylate monomer concentration, the ionic salt concentration, and the cell thickness as factors to investigate the electro-optical performance for the achievement of optimized fabrication conditions. The optimized device presented four switchable states modulated by external electric fields. The light transmittance of the device was changed by an alternative current (AC) electric field while the color change was realized by a direct current (DC) electric field. Variations of mesogen and ionic salt species can modulate the color and hue of devices, which solves the disadvantage of a single color for traditional EC devices. This work lays the foundation for realizing patterned multi-colored patterned displays and anti-counterfeiting via screen printing and inkjet printing techniques.
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Affiliation(s)
- Haiyu Xian
- School of Materials Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Lin Li
- School of Materials Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Yilei Ding
- School of Materials Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Mingjing Chu
- School of Materials Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Changqing Ye
- School of Materials Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
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17
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Zhao Y, Lang T, Li C, Yin W, Sun Y, Yao R, Ma C, Shi Z, Wang D, Miao Z. Effect of Electrospinning Network Instead of Polymer Network on the Properties of PDLCs. Molecules 2023; 28:molecules28083372. [PMID: 37110605 PMCID: PMC10146375 DOI: 10.3390/molecules28083372] [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: 03/16/2023] [Revised: 04/07/2023] [Accepted: 04/08/2023] [Indexed: 04/29/2023] Open
Abstract
In this study, polymer-dispersed liquid crystal (PDLC) membranes were prepared by combining prepolymer, liquid crystal, and nanofiber mesh membranes under UV irradiation. EM, POM, and electro-optic curves were then used to examine the modified polymer network structure and the electro-optical properties of these samples. As a result, the PDLCs with a specific amount of reticular nanofiber films had considerably improved electro-optical characteristics and antiaging capabilities. The advancement of PDLC incorporated with reticulated nanofiber films, which exhibited a faster response time and superior electro-optical properties, would greatly enhance the technological application prospects of PDLC-based smart windows, displays, power storage, and flexible gadgets.
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Affiliation(s)
- Yuzhen Zhao
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
| | - Tingting Lang
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
| | - Chaonian Li
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
| | - Wenbo Yin
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
- Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yitian Sun
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
| | - Ruijuan Yao
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
| | - Cheng Ma
- Xi'an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device, School of Electronic Information, Xijing University, Xi'an 710123, China
| | - Zuhui Shi
- Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Dong Wang
- Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Zongcheng Miao
- School of Artificial Intelligence, Optics and Electronics (iOPEN), Northwestern Polytechnical University, Xi'an 710072, China
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18
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Hadjichristov GB. Ion-Conducting Composites of Polymers and Nematic Liquid Crystals. ACS OMEGA 2023; 8:9684-9701. [PMID: 36969472 PMCID: PMC10034833 DOI: 10.1021/acsomega.2c07816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 02/27/2023] [Indexed: 06/18/2023]
Abstract
In the present mini-review are discussed the findings reported in the last five years on the ion-conducting composites of polymers and molecules of nematic liquid crystals (NLCs), as well as their applications at present and in the future. Nowadays, free-standing and flexible thin films of such organic composite electrolytes synthesized from plastics and nematic soft matter are among the technically important materials and components for use in energy storage and conversion devices and in organic soft electronics, sensorics, and mechatronics. Although the physicochemical mechanisms and effects in the ion-conducting polymer/NLCs composites are well understood, the possibility to find additional ways for improving their electrical conductivity and dielectric and mechanical properties is a challenge. The efforts in this research direction are important for the development of novel ion-conductor materials and further diversification of their applications. This mini-review is focused on the key characteristics of ion-conducting polymer/NLCs composites and the new trends in their fabrication. With relevant examples, the vast research opportunities, some proposed improvements, and the creative ideas associated with these advanced materials and their intelligent use are outlined.
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19
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A Stable PDLC Film with High Ageing Resistance from an Optimized System Containing Rigid Monomer. Molecules 2023; 28:molecules28041887. [PMID: 36838878 PMCID: PMC9962081 DOI: 10.3390/molecules28041887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 02/10/2023] [Accepted: 02/13/2023] [Indexed: 02/19/2023] Open
Abstract
With the switchability between transparent and light-scattering states, polymer-dispersed liquid crystals (PDLC) are widely used as smart windows, flexible display devices, projectors, and other devices. In outdoor applications, in addition to excellent electro-optical properties, there is also a high demand for film stability. In this work, a PDLC film with high mechanical strength and structural stability is prepared that can maintain stability at 80 °C for 2000 h. By choosing liquid crystals with a wide temperature range, adopting acrylate polymer monomers containing hydroxyl groups, and adjusting the polymer content, the PDLC film can work well from -20 °C to 80 °C. On this basis, the effects of the introduction of rigid monomers on the mechanical properties and electro-optical properties of PDLC films are investigated.
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20
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Zhang R, Zhang Z, Han J, Yang L, Li J, Song Z, Wang T, Zhu J. Advanced liquid crystal-based switchable optical devices for light protection applications: principles and strategies. LIGHT, SCIENCE & APPLICATIONS 2023; 12:11. [PMID: 36593244 PMCID: PMC9807646 DOI: 10.1038/s41377-022-01032-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 09/18/2022] [Accepted: 11/01/2022] [Indexed: 05/14/2023]
Abstract
With the development of optical technologies, transparent materials that provide protection from light have received considerable attention from scholars. As important channels for external light, windows play a vital role in the regulation of light in buildings, vehicles, and aircrafts. There is a need for windows with switchable optical properties to prevent or attenuate damage or interference to the human eye and light-sensitive instruments by inappropriate optical radiation. In this context, liquid crystals (LCs), owing to their rich responsiveness and unique optical properties, have been considered among the best candidates for advanced light protection materials. In this review, we provide an overview of advances in research on LC-based methods for protection against light. First, we introduce the characteristics of different light sources and their protection requirements. Second, we introduce several classes of light modulation principles based on liquid crystal materials and demonstrate the feasibility of using them for light protection. In addition, we discuss current light protection strategies based on liquid crystal materials for different applications. Finally, we discuss the problems and shortcomings of current strategies. We propose several suggestions for the development of liquid crystal materials in the field of light protection.
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Affiliation(s)
- Ruicong Zhang
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China
| | - Zhibo Zhang
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China
| | - Jiecai Han
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China
| | - Lei Yang
- Research Center of Analysis and Measurement, Harbin Institute of Technology, Harbin, 150080, China
| | - Jiajun Li
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China
| | - Zicheng Song
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China
| | - Tianyu Wang
- School of Energy Science & Engineering, Harbin Institute of Technology, Harbin, 150001, China.
| | - Jiaqi Zhu
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China.
- Key Laboratory of Micro-systems and Micro-structures Manufacturing, Ministry of Education, Harbin, 150080, China.
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21
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Temperature Controlled Mechanical Reinforcement of Polyacrylate Films Containing Nematic Liquid Crystals. Polymers (Basel) 2022; 14:polym14225024. [PMID: 36433151 PMCID: PMC9693148 DOI: 10.3390/polym14225024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/02/2022] [Accepted: 11/10/2022] [Indexed: 11/22/2022] Open
Abstract
This investigation reports on the thermomechanical properties of Poly-tripropyleneglycoldiacrylate (Poly-TPGDA)/liquid crystal (LC) blends, developed via free radical polymerization processes, which are induced by Electron Beam (EB) and Ultraviolet (UV) radiation. The EB-cured Poly-TPGDA network exhibits a higher glass transition temperature (Tg), a higher tensile storage, and Young moduli than the corresponding UV-cured sample, indicating a lower elasticity and a shorter distance between the two adjacent crosslinking points. Above Tg of Poly-TPGDA/LC blends, the LC behaves as a plasticizing agent, whereas, for EB-cured networks, at temperatures below Tg, the LC shows a strong temperature dependence on the storage tensile modulus: the LC reinforces the polymer due to the presence of nano-sized phase separated glassy LC domains, confirmed by electron microscopy observations. In the case of the UV-cured TPGDA/LC system, the plasticizing effect of the LC remains dominant in both the whole composition and the temperature ranges explored. The rubber elasticity and Tg of Poly-TPGDA/LC films were investigated using mechanical measurements.
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22
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Choi SH, Kim JA, Heo GS, Park HG. Electro-optical characteristics of polymer-dispersed liquid crystal containing copper (II) phthalocyanine as a function of UV irradiation time. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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23
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He Z, Yu P, Guo Z, Zhang Y, Feng X, Zhang H, Zhao Y, Miao Z. Effects of thiol‐ene click reaction on morphology and electro‐optical properties of polyhedral oligomeric silsesquioxane nanostructure‐based polymer dispersed liquid crystal film. POLYM ADVAN TECHNOL 2022. [DOI: 10.1002/pat.5868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Zemin He
- Xi'an Key Laboratory of Advanced Photo‐electronics Materials and Energy Conversion Device. School of Electronic Information Xijing University Xi'an China
| | - Ping Yu
- State Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao China
| | - Zhun Guo
- Xi'an Key Laboratory of Advanced Photo‐electronics Materials and Energy Conversion Device. School of Electronic Information Xijing University Xi'an China
| | - Yongming Zhang
- Xi'an Key Laboratory of Advanced Photo‐electronics Materials and Energy Conversion Device. School of Electronic Information Xijing University Xi'an China
| | - Xueyan Feng
- Shaanxi Yide Fengda Testing Technology Service Limited Baoji China
| | - Huimin Zhang
- Xi'an Key Laboratory of Advanced Photo‐electronics Materials and Energy Conversion Device. School of Electronic Information Xijing University Xi'an China
| | - Yuzhen Zhao
- Xi'an Key Laboratory of Advanced Photo‐electronics Materials and Energy Conversion Device. School of Electronic Information Xijing University Xi'an China
| | - Zongcheng Miao
- School of Artificial Intelligence, Optics and Electronics (Iopen) Northwestern Polytechnical University Xi'an China
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24
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Yu M, Xu J, Wang T, Zhang L, Wei H, Zou C, Gao Y, Yang H. Effects of acrylate monomers with different alkyl chain structure on the electro‐optical properties and microstructure of polymer dispersed liquid crystals. J Appl Polym Sci 2022. [DOI: 10.1002/app.53056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Meina Yu
- Institute for Advanced Materials and Technology University of Science and Technology Beijing Beijing China
| | - Jianjun Xu
- School of Materials Science and Engineering University of Science and Technology Beijing Beijing China
| | - Tianyang Wang
- School of Materials Science and Engineering University of Science and Technology Beijing Beijing China
| | - Luoning Zhang
- Institute for Advanced Materials and Technology University of Science and Technology Beijing Beijing China
| | - Huiyun Wei
- School of Mathematics and Physics University of Science and Technology Beijing Beijing China
| | - Cheng Zou
- Institute for Advanced Materials and Technology University of Science and Technology Beijing Beijing China
- Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology Beijing Beijing China
| | - Yanzi Gao
- Institute for Advanced Materials and Technology University of Science and Technology Beijing Beijing China
| | - Huai Yang
- Institute for Advanced Materials and Technology University of Science and Technology Beijing Beijing China
- Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology Beijing Beijing China
- School of Materials Science and Engineering Peking University Beijing China
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25
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Faster switching polymer dispersed liquid crystal devices incorporated with functionalized SWCNTs. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118905] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Polymer-Dispersed Cholesteric Liquid Crystal under Homeotropic Anchoring: Electrically Induced Structures with λ1/2-Disclination. Polymers (Basel) 2022; 14:polym14071454. [PMID: 35406327 PMCID: PMC9002932 DOI: 10.3390/polym14071454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 03/25/2022] [Accepted: 03/31/2022] [Indexed: 11/30/2022] Open
Abstract
Orientational structures of polymer-dispersed cholesteric liquid crystal under homeotropic anchoring and their transformations under the action of an electric field are studied. The switching of cholesteric droplets between different topological states are experimentally and theoretically demonstrated. Structures with λ+1/2-disclination are found and considered. These structures are formed during the transformation of a twisted toroidal configuration induced by a decrease in the electric field when a relative chiral parameter N0>6.3. The transformation of the initial structure with a bipolar distribution of the helix axis into a twisted toroidal configuration and then into a structure with λ+1/2-disclination is investigated in detail. The behavior of these structures under the influence of an external electric field, as well as the appearance of structures with λ−1/2-disclination, are studied. Obtained results are promising for the development of optical materials with programmable properties.
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Wang X, Hu W, Chen H, Saeed MH, Huang J, Hu J, Ren Y, Xu J, Zhang L, Yu M, Zhang H, Yang H. Effects of chemically functionalized
TiO
2
nanoparticles on the
UV
‐shielding characteristics of polymer‐dispersed liquid crystals. POLYM ADVAN TECHNOL 2022. [DOI: 10.1002/pat.5621] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Xiao Wang
- State Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao China
| | - Wei Hu
- School of Materials Science and Engineering Peking University Beijing China
- School of Materials Science and Engineering University of Science and Technology Beijing Beijing China
| | - Hongren Chen
- School of Materials Science and Engineering University of Science and Technology Beijing Beijing China
| | | | - Junyi Huang
- School of Materials Science and Engineering Peking University Beijing China
| | - Junmei Hu
- School of Materials Science and Engineering University of Science and Technology Beijing Beijing China
| | - Yunxiao Ren
- School of Materials Science and Engineering University of Science and Technology Beijing Beijing China
| | - Jianjun Xu
- School of Materials Science and Engineering University of Science and Technology Beijing Beijing China
| | - Lanying Zhang
- School of Materials Science and Engineering Peking University Beijing China
| | - Meina Yu
- School of Materials Science and Engineering University of Science and Technology Beijing Beijing China
| | - Haiquan Zhang
- State Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao China
| | - Huai Yang
- School of Materials Science and Engineering Peking University Beijing China
- School of Materials Science and Engineering University of Science and Technology Beijing Beijing China
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Abstract
Smart soft materials are envisioned to be the building blocks of the next generation of advanced devices and digitally augmented technologies. In this context, liquid crystals (LCs) owing to their responsive and adaptive attributes could serve as promising smart soft materials. LCs played a critical role in revolutionizing the information display industry in the 20th century. However, in the turn of the 21st century, numerous beyond-display applications of LCs have been demonstrated, which elegantly exploit their controllable stimuli-responsive and adaptive characteristics. For these applications, new LC materials have been rationally designed and developed. In this Review, we present the recent developments in light driven chiral LCs, i.e., cholesteric and blue phases, LC based smart windows that control the entrance of heat and light from outdoor to the interior of buildings and built environments depending on the weather conditions, LC elastomers for bioinspired, biological, and actuator applications, LC based biosensors for detection of proteins, nucleic acids, and viruses, LC based porous membranes for the separation of ions, molecules, and microbes, living LCs, and LCs under macro- and nanoscopic confinement. The Review concludes with a summary and perspectives on the challenges and opportunities for LCs as smart soft materials. This Review is anticipated to stimulate eclectic ideas toward the implementation of the nature's delicate phase of matter in future generations of smart and augmented devices and beyond.
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Affiliation(s)
- Hari Krishna Bisoyi
- Advanced Materials and Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, Ohio 44242, United States
| | - Quan Li
- Advanced Materials and Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, Ohio 44242, United States.,Institute of Advanced Materials, School of Chemistry and Chemical Engineering, and Jiangsu Hi-Tech Key Laboratory for Biomedical Research, Southeast University, Nanjing 211189, China
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Hadjichristov GB, Vlakhov TE, Marinov YG, Scaramuzza N. Ion-Conducting Flexible Thin Films of Composites from Poly(ethylene oxide) and Nematic Liquid Crystals E8-Characterization by Impedance and Dielectric Relaxation Spectroscopy. Polymers (Basel) 2021; 13:4465. [PMID: 34961015 PMCID: PMC8704298 DOI: 10.3390/polym13244465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/03/2021] [Accepted: 12/16/2021] [Indexed: 11/17/2022] Open
Abstract
Complex electrical impedance and dielectric spectroscopy were applied to study the dielectric relaxations and their thermal behavior in ion-conducting composites/complexes from polymer poly(ethylene oxide) (PEO) and E8 nematic liquid crystals (LCs), at the compositional ratio PEO:E8 = 70:30 wt%. Flexible thin films of PEO/E8 with a thickness of 150 μm were inspected, as well as such films from Na+ ion-conducting electrolyte PEO/E8/NaIO4 with the same PEO:E8 compositional ratio, but additionally containing 10 wt.% from the salt sodium metaperiodate (NaIO4) as a dopant of Na+ ions. The molecular dynamics, namely the dielectric relaxation of PEO/E8 and PEO/E8/NaIO4, were characterized through analyses of complex impedance and dielectric spectra measured in the frequency range of 1 Hz-1 MHz, under variation of temperature from below to above the glass-transition temperature of these composites. The relaxation and polarization of dipole formations in PEO/E8 and PEO/E8/NaIO4 were evidenced and compared in terms of both electrical impedance and dielectric response depending on temperature. The results obtained for molecular organization, molecular relaxation dynamics, and electric polarization in the studied ion-conducting polymer/LC composites/complexes can be helpful in the optimization of their structure and performance, and are attractive for applications in flexible organic electronics, energy storage devices, and mechatronics.
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Affiliation(s)
- Georgi B. Hadjichristov
- Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia, Bulgaria; (T.E.V.); (Y.G.M.)
| | - Todor E. Vlakhov
- Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia, Bulgaria; (T.E.V.); (Y.G.M.)
| | - Yordan G. Marinov
- Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia, Bulgaria; (T.E.V.); (Y.G.M.)
| | - Nicola Scaramuzza
- Dipartimento di Fisica, Università degli Studi della Calabria (UNICAL), Via P. Bucci, Cubo 33B, 87036 Rende, Italy;
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