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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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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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Raczyńska V, Górny K, Raczyński P, Dendzik Z, Starzonek S. Two-dimensional phases of confined 5-cyano-biphenyl: Computer simulation study. Phys Rev E 2023; 108:034702. [PMID: 37849085 DOI: 10.1103/physreve.108.034702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 08/25/2023] [Indexed: 10/19/2023]
Abstract
The properties of composites of mesogens and two-dimensional (2D) materials are of great interest due to their practical applications in flexible displays, optoelectronics, microelectronics, and novel nanodevices. The properties of such composites are very complex and strongly depend on the interactions between the host material and the mesogen filling. We have performed molecular dynamics simulations for 4-cyano-4^{'}-pentylbiphenyl embedded between graphene and hexagonal 2D boron nitride layers. The structural and dynamical properties of such systems were investigated in terms of the order parameters, density profiles, mean square displacement, and autocorrelation function of the single-molecule dipole moment. Our simulations have shown that the mesogenic molecules form highly stable ordered layered structures and that their dynamics are strongly related to the structural properties. We have investigated not only the effects of the polarization of the host material, but also the effects of the spatial repetition of such composites by using two models of mesogens embedded in 2D layers: the direct sheet and the structure formed by multiplying a single unit of the composite in the direction perpendicular to the substrate surface.
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Affiliation(s)
- Violetta Raczyńska
- Faculty of Science and Technology, University of Silesia in Katowice, ul. 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - Krzysztof Górny
- Faculty of Science and Technology, University of Silesia in Katowice, ul. 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - Przemysław Raczyński
- Faculty of Science and Technology, University of Silesia in Katowice, ul. 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - Zbigniew Dendzik
- Faculty of Science and Technology, University of Silesia in Katowice, ul. 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - Szymon Starzonek
- Laboratory of Physics, Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, 1000 Ljubljana, Slovenia
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Furhan, Ramesan MT. High performance optical and electrical properties of zinc oxide reinforced poly(diphenylamine) nanocomposites for optoelectronic applications. POLYM ENG SCI 2022. [DOI: 10.1002/pen.26114] [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)
- Furhan
- Centre for Polymer Science and Technology, Department of Chemistry University of Calicut Kerala India
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Sankar S, Ramesan MT. Synthesis, characterization, conductivity, and gas‐sensing performance of copolymer nanocomposites based on copper alumina and poly(aniline‐
co
‐pyrrole). POLYM ENG SCI 2022. [DOI: 10.1002/pen.26014] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- S. Sankar
- Centre for Polymer Science and Technology, Department of Chemistry University of Calicut Malappuram Kerala India
| | - M. T. Ramesan
- Centre for Polymer Science and Technology, Department of Chemistry University of Calicut Malappuram Kerala India
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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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Labeeb AM, Ward YA, Fikry M. Thermal control of tunable photonic optical bandgaps in different cholesteric liquid crystals mixtures. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117179] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Saeed MH, Zhang S, Cao Y, Zhou L, Hu J, Muhammad I, Xiao J, Zhang L, Yang H. Recent Advances in The Polymer Dispersed Liquid Crystal Composite and Its Applications. Molecules 2020; 25:E5510. [PMID: 33255525 PMCID: PMC7727789 DOI: 10.3390/molecules25235510] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/12/2020] [Accepted: 11/13/2020] [Indexed: 11/16/2022] Open
Abstract
Polymer dispersed liquid crystals (PDLCs) have kindled a spark of interest because of their unique characteristic of electrically controlled switching. However, some issues including high operating voltage, low contrast ratio and poor mechanical properties are hindering their practical applications. To overcome these drawbacks, some measures were taken such as molecular structure optimization of the monomers and liquid crystals, modification of PDLC and doping of nanoparticles and dyes. This review aims at detailing the recent advances in the process, preparations and applications of PDLCs over the past six years.
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Affiliation(s)
- Mohsin Hassan Saeed
- Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China; (M.H.S.); (Y.C.); (L.Z.); (I.M.)
| | - Shuaifeng Zhang
- Beijing Advanced Innovation Center for Materials Genome Engineering, Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China; (S.Z.); (J.H.)
| | - Yaping Cao
- Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China; (M.H.S.); (Y.C.); (L.Z.); (I.M.)
| | - Le Zhou
- Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China; (M.H.S.); (Y.C.); (L.Z.); (I.M.)
| | - Junmei Hu
- Beijing Advanced Innovation Center for Materials Genome Engineering, Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China; (S.Z.); (J.H.)
| | - Imran Muhammad
- Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China; (M.H.S.); (Y.C.); (L.Z.); (I.M.)
| | - Jiumei Xiao
- Department of Applied Mechanics, University of Sciences and Technology Beijing, Beijing 100083, China;
| | - Lanying Zhang
- Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China; (M.H.S.); (Y.C.); (L.Z.); (I.M.)
| | - Huai Yang
- Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China; (M.H.S.); (Y.C.); (L.Z.); (I.M.)
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