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Rim M, Kang DG, Jung D, Lim SI, Lee KM, Godman NP, McConney ME, De Sio L, Ahn SK, Jeong KU. Remote-controllable and encryptable smart glasses: a photoresponsive azobenzene molecular commander determines the molecular alignments of liquid crystal soldiers. NANOSCALE 2022; 14:8271-8280. [PMID: 35586949 DOI: 10.1039/d2nr01382g] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
For the development of optically encryptable smart glass that can control the molecular alignment of liquid crystals (LCs), an azobenzene-based reactive molecule (ARM) capable of trans-cis photoisomerization is newly designed and synthesized. Photo-triggered LC-commandable smart glasses are successfully constructed by the surface functionalization technique using 3-aminopropyltriethoxysilane (APTMS) coupling agent and an ARM. The surface functionalization with the ARM is verified by spectroscopic analysis and various observations including changes in the wettability and surface morphology. Using the ARM-treated substrate, the LC command cell which can effectively switch the molecular orientation of nematic LC (E7) by the irradiation of UV and visible light is demonstrated. The results of optical investigation demonstrate the directional correlation between light and photoisomerization, revealing the tilt mechanism of azobenzene units. The capability to control the molecular orientation of LCs remotely and selectively allows the development of remote-controllable and encryptable smart glasses.
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Affiliation(s)
- Minwoo Rim
- Department of Polymer-Nano Science and Technology, Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju 54896, Republic of Korea.
| | - Dong-Gue Kang
- Department of Polymer-Nano Science and Technology, Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju 54896, Republic of Korea.
| | - Dayoung Jung
- Department of Polymer-Nano Science and Technology, Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju 54896, Republic of Korea.
| | - Seok-In Lim
- Department of Polymer-Nano Science and Technology, Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju 54896, Republic of Korea.
| | - Kyung Min Lee
- US Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433, USA
| | - Nicholas P Godman
- US Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433, USA
| | - Michael E McConney
- US Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433, USA
| | - Luciano De Sio
- Department of Medico-Surgical Science and Biotechnologies, Center for Biophotonics, Sapienza University of Rome, Latina 04100, Italy
| | - Suk-Kyun Ahn
- Department of Polymer Science and Engineering, Pusan National University, Busan 46241, Republic of Korea.
| | - Kwang-Un Jeong
- Department of Polymer-Nano Science and Technology, Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju 54896, Republic of Korea.
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Tatipamula AK, Gelbaor Kirzhner M, Chaudhary A, Klebanov M, Abdulhalim I. Electro-Optical properties of photoaligned Liquid Crystal cells prepared with obliquely irradiated Chalcogenide glasses. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2021.118087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Son I, Son SR, An J, Choi JW, Kim S, Lee WY, Lee JH. Photoluminescent surface-functionalized graphene quantum dots for spontaneous interfacial homeotropic orientation of liquid crystals. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.115901] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Yoon HJ, Lee D, Jin HS, Panov VP, Song JK. Self-alignment technique of liquid crystal using a novel additive containing thiol group. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.114557] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Hou TC, Jeng SC. Application of Bombyx mori Silk Fibroin Films for Liquid-Crystal Devices. ACS APPLIED BIO MATERIALS 2020; 3:8575-8580. [PMID: 35019628 DOI: 10.1021/acsabm.0c00959] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Biocompatible and biodegradable silk fibroin films show promise as an eco-friendly biomaterial with excellent mechanical, thermal, and optical transparency properties. In contrast, polyimide (PI) films adopted in the liquid-crystal display (LCD) industry for aligning LC molecules are synthesized using toxic chemicals, which are nonrecyclable and nonbiodegradable. In this work, Bombyx mori silk fibroin films are fabricated from the aqueous solution and applied as alignment films for LCDs. The thermal properties of the prepared regenerated silk fibroin materials under different heat treatment temperatures are investigated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The crystallinity of different heat-treated silk fibroin materials is determined by infrared spectroscopy. The silk fibroin film treated at a higher temperature exhibits better thermal stability due to the higher crystallinity of the β-form structure. The LCDs using silk fibroin alignment films show a low pretilt angle of 0.5° and an anchoring energy of ∼10-3 J/m2 similar to those of the conventional polyimide films.
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Kuang ZY, Fan YJ, Tao L, Li ML, Zhao N, Wang P, Chen EQ, Fan F, Xie HL. Alignment Control of Nematic Liquid Crystal using Gold Nanoparticles Grafted by the Liquid Crystalline Polymer with Azobenzene Mesogens as the Side Chains. ACS APPLIED MATERIALS & INTERFACES 2018; 10:27269-27277. [PMID: 30028118 DOI: 10.1021/acsami.8b07483] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The gold nanoparticles highly grafted by a liquid crystalline polymer (LCP) with azobenzene mesogens as the side chain (denoted as Au@TE-PAzo NPs) are successfully designed and synthesized by the two-phase Brust-Schiffrin method. The chemical structures of the monomer and polymer ligands have been confirmed by nuclear magnetic resonance, and the molecular weight of the polymer is determined by gel permeation chromatography. The combined analysis of transmission electron microscopy and thermogravimetric analysis shows that the size of the nanoparticles is 2.5(±0.4) nm and the content of the gold in the Au@TE-PAzo NPs is ca. 17.58%. The resultant Au@TE-PAzo NPs can well disperse in the nematic LC of 5CB. The well-dispersed mixture with appropriate doping concentrations can automatically form a perfect homeotropic alignment in the LC cell. The homeotropic alignment is attributed to the brush formed by Au@TE-PAzo NPs on the substrate, wherein the Au@TE-PAzo NPs gradually diffuse onto the substrate from the mixture. On the contrary, the pure side chain LCPs cannot yield vertical alignment of 5CB, which indicates that the alignment of 5CB is ascribed to the synergistic interaction of the nanoparticles and the grafted LCPs. Moreover, Au@TE-PAzo NPs show excellent film-forming property on account of their periphery of high densely grafted LCPs, which can form uniform thin film by spin-coating. The resultant thin film also can prompt the automatical vertical alignment of the nematic 5CB. Further, upon alternative irradiation of UV and visible light, the alignment of 5CB reversibly switches between vertical and random orientation because of the trans-cis photoisomerization of the azobenzene group on the periphery of Au@TE-PAzo NPs. These experimental results suggest that this kind of nanoparticles can be potentially applied in constructing the remote-controllable optical devices.
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Affiliation(s)
| | | | | | | | | | | | - Er-Qiang Chen
- Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , China
| | - Fan Fan
- Key Laboratory for Micro-/Nano-Optoelectronic Devices of Ministry of Education, School of Physics and Electronics , Hunan University , Changsha 410082 , China
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Polyhedral Oligomeric Silsesquioxane Films for Liquid Crystal Alignment. COLLOIDS AND INTERFACES 2018. [DOI: 10.3390/colloids2010009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Im P, Choi YJ, Yoon WJ, Kang DG, Park M, Kim DY, Lee CR, Yang S, Lee JH, Jeong KU. Multifunctional Optical Thin Films Fabricated by the Photopolymerization of Uniaxially Oriented Lyotropic Liquid Crystal Monomers for Electro-Optical Devices. Sci Rep 2016; 6:36472. [PMID: 27812042 PMCID: PMC5095604 DOI: 10.1038/srep36472] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 10/14/2016] [Indexed: 12/19/2022] Open
Abstract
A multifunctional optical thin film (MOTF) is fabricated by coating the newly synthesized perylene-based reactive mesogen (PBRM) and stabilized by the subsequent photopolymerization. Based on the spectroscopic results combined with morphological observations, it is found that nematic liquid crystal (NLC) is aligned parallel to the molecular long axis of PBRM not only due to the long-range physical anchoring effect but also due to the short-range molecular physical interactions between alignment layer and NLC molecules. From the electro-optical properties of LC test cells fabricated with the PBRM MOTF, it is clearly demonstrated that the PBRM MOTF can work as the planar LC alignment layer as well as the in-cell coatable polarizer. The coatable PBRM MOTF from lyotropic chromonic reactive mesogens can pave a new way for the flexible optoelectronic devices.
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Affiliation(s)
- Pureun Im
- BK21 Plus Haptic Polymer Composite Research Team &Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju, 54896, Republic of Korea
| | - Yu-Jin Choi
- BK21 Plus Haptic Polymer Composite Research Team &Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju, 54896, Republic of Korea
| | - Won-Jin Yoon
- BK21 Plus Haptic Polymer Composite Research Team &Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju, 54896, Republic of Korea
| | - Dong-Gue Kang
- BK21 Plus Haptic Polymer Composite Research Team &Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju, 54896, Republic of Korea
| | - Minwook Park
- BK21 Plus Haptic Polymer Composite Research Team &Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju, 54896, Republic of Korea
| | - Dae-Yoon Kim
- BK21 Plus Haptic Polymer Composite Research Team &Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju, 54896, Republic of Korea
| | - Cheul-Ro Lee
- Division of Advanced Materials Engineering, Chonbuk National University, Jeonju, 54896, Republic of Korea
| | - Seungbin Yang
- Division of Electronics Engineering, Chonbuk National University, Jeonju, 54896, Republic of Korea
| | - Ji-Hoon Lee
- Division of Electronics Engineering, Chonbuk National University, Jeonju, 54896, Republic of Korea
| | - Kwang-Un Jeong
- BK21 Plus Haptic Polymer Composite Research Team &Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju, 54896, Republic of Korea
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Abstract
UV treatment has applied to modify the surface wettability of ZnO films for controlling the liquid crystal alignment.
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Affiliation(s)
- Jia-Wei Hu
- Institute of Photonics System
- National Chiao Tung University
- Tainan 711
- Taiwan
| | - Sheng-Hsiung Yang
- Institute of Lighting and Energy Photonics
- National Chiao Tung University
- Tainan 711
- Taiwan
| | - Shie-Chang Jeng
- Institute of Imaging and Biomedical Photonics
- National Chiao Tung University
- Tainan 711
- Taiwan
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Chung YF, Chen MZ, Yang SH, Jeng SC. Tunable Surface Wettability of ZnO Nanoparticle Arrays for Controlling the Alignment of Liquid Crystals. ACS APPLIED MATERIALS & INTERFACES 2015; 7:9619-9624. [PMID: 25895105 DOI: 10.1021/acsami.5b01157] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The control of the liquid crystal (LC) alignment is very important for both academic research and practical applications. LC molecules aligned on the ZnO nanoparticle arrays (ZnO NPAs) are demonstrated and the pretilt angles of LCs can be controlled by using ZnO NPAs with different surface wettability. The wettability of ZnO NPAs fabricated by the solution-based hydrothermal method can be controlled by changing the annealing temperature of the as-prepared ZnO NPAs. The measurements of the energy-dispersive spectra and photoluminescence have shown that the chemical properties of ZnO NPAs have been changed with the annealing temperature. Our results show that the pretilt angle of LCs can be tuned continuously from ∼0 to ∼90° as the contact angle of water on ZnO NPAs changes from 33 to 108°.
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Affiliation(s)
- Yueh-Feng Chung
- †Institute of Photonics System, ‡Institute of Lighting and Energy Photonics, and §Institute of Imaging and Biomedical Photonics, National Chiao Tung University, Tainan 711, Taiwan
| | - Mu-Zhe Chen
- †Institute of Photonics System, ‡Institute of Lighting and Energy Photonics, and §Institute of Imaging and Biomedical Photonics, National Chiao Tung University, Tainan 711, Taiwan
| | - Sheng-Hsiung Yang
- †Institute of Photonics System, ‡Institute of Lighting and Energy Photonics, and §Institute of Imaging and Biomedical Photonics, National Chiao Tung University, Tainan 711, Taiwan
| | - Shie-Chang Jeng
- †Institute of Photonics System, ‡Institute of Lighting and Energy Photonics, and §Institute of Imaging and Biomedical Photonics, National Chiao Tung University, Tainan 711, Taiwan
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Lin GJ, Chen TJ, Tsai YW, Lin YT, Wu JJ, Yang YJ. Performance enhancement using a non-uniform vertical electric field and polymer networks for in-plane switching of multi-pretilt, vertically aligned liquid crystal devices. OPTICS LETTERS 2014; 39:6225-6228. [PMID: 25361320 DOI: 10.1364/ol.39.006225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A simple and reproducible alignment method for fabricating vertically aligned (VA) liquid crystal (LC) cells with a multi-pretilt structure is developed. A non-uniform vertical electric field is employed in the LC/monomer mixed cells during the photocuring process, and two pretilt domains with a functional small pretilt angle (∼1.6°) in the stabilized VA LC/polymer cells are achieved. The enhanced electro-optical performance of the cell driven by an in-plane switching field is demonstrated. Compared to the pure cell, the 2 wt.% pretilt angle cell shows 36%, 64%, and 76% improvement in the optical switch, the gray-level rise time, and the gray-level fall time responses, respectively, which are obtained at a low driving voltage (≤12 V). When applied to LC devices, the proposed method not only effectively benefits the LC molecular alignment, but it also significantly boosts the electro-optical performance.
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Wang SY, Wu HM, Yang KH. Simple and direct measurements of pretilt angles in hybrid-aligned nematic liquid-crystal cells. APPLIED OPTICS 2013; 52:5106-5111. [PMID: 23872755 DOI: 10.1364/ao.52.005106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 06/20/2013] [Indexed: 06/02/2023]
Abstract
We have developed a general approach to perform direct measurements of the pretilt angles from 0° to 75° in hybrid-aligned nematic (HAN) liquid-crystal cells whose cell gaps can also be accurately determined with the help of known pretilt angles. In this paper, we have used a Zeeman laser system to measure the angular-dependence phase retardation of the HAN cells and MATLAB mathematical software to carry out theoretical calculations and fit the measured data to derive the pretilt angles. In general, pretilt angles adjacent to opposite substrates of a HAN cell are different. Our measured pretilt angles of the HAN cell were in good agreement with the measured pretilt angles of two accompanying homogenous cells whose alignment methods were the same as applied to opposite substrates of the HAN cell, respectively. The advantage of direct measurement is easily applicable to measure the pretilt angles of aged HAN cells.
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Affiliation(s)
- Sheng-Ya Wang
- Institute of Photonic Systems, National Chiao Tung University, No. 301, Gaofa 3rd Road, Guiren District, Tainan City 711, Taiwan.
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Stamatoiu O, Mirzaei J, Feng X, Hegmann T. Nanoparticles in liquid crystals and liquid crystalline nanoparticles. Top Curr Chem (Cham) 2011; 318:331-93. [PMID: 21928012 DOI: 10.1007/128_2011_233] [Citation(s) in RCA: 138] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Combinations of liquid crystals and materials with unique features as well as properties at the nanoscale are reviewed. Particular attention is paid to recent developments, i.e., since 2007, in areas ranging from liquid crystal-nanoparticle dispersions to nanomaterials forming liquid crystalline phases after surface modification with mesogenic or promesogenic moieties. Experimental and synthetic approaches are summarized, design strategies compared, and potential as well as existing applications discussed. Finally, a critical outlook into the future of this fascinating field of liquid crystal research is provided.
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Affiliation(s)
- Oana Stamatoiu
- Department of Chemistry, University of Manitoba, Winnipeg, MB, Canada, R3T 2N2
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