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Önsal G, Uğurlu O, Kaynar ÜH, Türsel Eliiyi D. Minimization of the threshold voltage parameter of the co-doped ZnO doped liquid crystals by machine learning algorithms. Sci Rep 2023; 13:12802. [PMID: 37550479 PMCID: PMC10406893 DOI: 10.1038/s41598-023-39923-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 08/02/2023] [Indexed: 08/09/2023] Open
Abstract
This study aims to examine the influence of the co-doped semiconductor nanostructure (Al-Cu):ZnO on the electro-optical properties of the E7 coded pure nematic liquid crystal structures and minimize the threshold voltage of pure E7 liquid crystal. To determine the ideal concentration ratios of the materials for the minimum threshold voltage, we employed different machine learning algorithms. In this context, we first produced twelve composite structures through lab experimentation with different concentrations and created an experimental dataset for the machine learning algorithms. Next, the ideal concentration ratios were estimated using the AdaBoost algorithm, which has an [Formula: see text] of 96% on the experimental dataset. Finally, additional composite structures having the estimated concentration ratios were produced. The results show that, with the help of the employed machine learning algorithms, the threshold voltage of pure E7 liquid crystal was reduced by 19% via the (Al-Cu):ZnO doping.
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Affiliation(s)
- Gülnur Önsal
- Department of Fundamental Sciences, Izmir Bakircay University, 35665, Izmir, Turkey.
| | - Onur Uğurlu
- Department of Fundamental Sciences, Izmir Bakircay University, 35665, Izmir, Turkey
| | - Ümit H Kaynar
- Department of Fundamental Sciences, Izmir Bakircay University, 35665, Izmir, Turkey
| | - Deniz Türsel Eliiyi
- Department of Industrial Engineering, Izmir Bakircay University, 35665, Izmir, Turkey
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2
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Anu, Varshney D, Yadav K, Prakash J, Meena H, Singh G. Tunable dielectric and memory features of ferroelectric layered perovskite Bi4Ti3O12 nanoparticles doped nematic liquid crystal composite. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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3
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Polymer beads dispersed liquid crystal devices (
PBLCD
) achieved by predesigned radially constructed polymeric particles. J Appl Polym Sci 2022. [DOI: 10.1002/app.53037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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4
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Kumari A, Dhawan S, Singh H, Haridas V, Sinha A. Pseudopeptidic polymers for modulating electro-optic switching, dielectric and electrical properties of liquid crystal. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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5
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Parveen A, Prakash J, Singh G. Impact of strontium titanate nanoparticles on the dielectric, electro-optical and electrical response of a nematic liquid crystal. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118907] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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6
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Superior improvement in dynamic response of liquid crystal lens using organic and inorganic nanocomposite. Sci Rep 2021; 11:17349. [PMID: 34462538 PMCID: PMC8405812 DOI: 10.1038/s41598-021-96991-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 08/19/2021] [Indexed: 11/08/2022] Open
Abstract
In this study, the response time of a 4 mm-aperture hole-patterned liquid crystal (HLC) lens has been significantly improved with doping of N-benzyl-2-methyl-4-nitroaniline (BNA) and rutile titanium dioxide nanoparticle (TiO2 NP) nanocomposite. The proposed HLC lens provides the focus and defocus times that are 8.5× and 14× faster than the pristine HLC lens, respectively. Meanwhile, the focus and defocus times of the proposed HLC lens reach the order of millisecond. Result shows that the synergistic effect of BNA and TiO2 NP induces a 78% decrement in the viscosity of pristine LC mixture that significantly shortens the focus and defocus times of HLC lens. The remarkable decrement in viscosity is mainly attributed to spontaneous polarization electric fields from the permanent dipole moments of the additives. Besides, the strengthened electric field surrounding TiO2 NP assists in decreasing the focus time of HLC lens. The focus and defocus times of HLC lens are related to the wavefront (or phase profile) bending speed. The time-dependent phase profiles of the HLC lenses with various viscosities are calculated. This result shows the decrease in wavefront bending time is not simply proportional to viscosity decrement. Furthermore, the proposed HLC lens emerges a larger tunable focus capability within smaller voltage interval than the pristine HLC lens.
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7
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Electro-optical characterization of a weakly polar liquid crystalline compound influenced polyvinyl pyrrolidone capped gold nanoparticles. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.115172] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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8
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Perera K, Nemati A, Mann EK, Hegmann T, Jákli A. Converging Microlens Array Using Nematic Liquid Crystals Doped with Chiral Nanoparticles. ACS APPLIED MATERIALS & INTERFACES 2021; 13:4574-4582. [PMID: 33411492 DOI: 10.1021/acsami.0c21044] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Nematic liquid crystals of achiral molecules or racemic mixtures of chiral ones form flat films when suspended in submillimeter size grids and submerged under water. Recently, it has been shown (Popov et al., 2017) that films of nematic liquid crystals doped with chiral molecules adopt biconvex lens shapes underwater. The curved shape together with degenerate planar anchoring leads to a radial variation of the optical axis along the plane of the film, providing a Pancharatnam-Berry-type phase lens that modifies geometric optical imaging. Here, we describe nematic liquid crystal microlenses formed by the addition of chiral nanoparticles. It is found that the helical twisting power of the nanoparticles, the key factor to form the lens, is about 400 μm-1, greater than that of the strongest molecular chiral dopants. We demonstrate imaging capabilities and measure the shape as well as the focal length of the chiral nanoparticle-doped liquid crystal lens. We show that measuring the shape of the lens allows one to calculate the helical pitch of the chiral nematic liquid crystal and thus determine the helical twisting power of the chiral ligand-capped nanoparticles. Such measurements require the use of only nanograms of chiral nanoparticles, which is 3 orders of magnitude less than that required by conventional techniques. Since NPs are sensitive to external stimuli such as light and electric and magnetic fields, the use of chiral NPs may allow the achievement of tunable optical properties for such microlens arrays.
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Affiliation(s)
- Kelum Perera
- Physics Department, Kent State University, Kent, Ohio 44242, United States
| | - Ahlam Nemati
- Advanced Materials and Liquid Crystal Institute Kent State University, Kent, Ohio 44242, United States
- Materials Science Graduate Program, Kent State University, Kent, Ohio 44242, United States
| | - Elizabeth K Mann
- Physics Department, Kent State University, Kent, Ohio 44242, United States
- Materials Science Graduate Program, Kent State University, Kent, Ohio 44242, United States
| | - Torsten Hegmann
- Advanced Materials and Liquid Crystal Institute Kent State University, Kent, Ohio 44242, United States
- Materials Science Graduate Program, Kent State University, Kent, Ohio 44242, United States
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, United States
- Brain Health Research Institute, Kent State University, Kent, Ohio 44242, United States
| | - Antal Jákli
- Physics Department, Kent State University, Kent, Ohio 44242, United States
- Advanced Materials and Liquid Crystal Institute Kent State University, Kent, Ohio 44242, United States
- Materials Science Graduate Program, Kent State University, Kent, Ohio 44242, United States
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9
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A Comparative Study on Electro-Optic Effects of Organic N-Benzyl-2-Methyl-4-Nitroaniline and Morpholinium 2-Chloro-4-Nitrobenzoate Doped in Nematic Liquid Crystals E7. Polymers (Basel) 2020; 12:polym12122977. [PMID: 33322206 PMCID: PMC7764116 DOI: 10.3390/polym12122977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 12/11/2020] [Accepted: 12/11/2020] [Indexed: 12/04/2022] Open
Abstract
Improvements in electro-optical responses of LC devices by doping organic N-benzyl-2-methyl-4-nitroaniline (BNA) and Morpholinium 2-chloro-4-nitrobenzoate (M2C4N) in nematic liquid crystals (LCs) have been reported in this study. BNA and M2C4N-doped LC cells have the fall time that is fivefold and threefold faster than the pristine LC cell, respectively. The superior performance in fall time of BNA-doped LC cell is attributed to the significant decrements in the rotational viscosity and threshold voltage by 44% and 25%, respectively, and a strong additional restoring force resulted from the spontaneous polarization electric field of BNA. On the other hand, the dielectric anisotropy (Δε) of LC mixture is increased by 16% and 6%, respectively, with M2C4N and BNA dopants. M2C4N dopant induces a large dielectric anisotropy, because the phenyl-amine/hydroxyl in M2C4N induces a strong intermolecular interaction with LCs. Furthermore, BNA dopant causes a strong absorbance near the wavelength of 400 nm that filters the blue light. The results indicate that M2C4N doping can be used to develop a high Δε of LC mixture, and BNA doping is appropriate to fabricate a fast response and blue-light filtering LC device. Density Functional Theory calculation also confirms that BNA and M2C4N increase the dipole moment, polarization anisotropy, and hence Δε of LC mixture.
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10
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Chemingui M, Singh UB, Yadav N, Dabrowski RS, Dhar R. Effect of iron oxide (γ-Fe2O3) nanoparticles on the morphological, electro-optical and dielectric properties of a nematic liquid crystalline material. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.114299] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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11
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Hsu PH, Yougbaré S, Kuo JC, Krisnawati DI, Jazidie A, Nuh M, Chou PT, Hsiao YC, Kuo TR. One-Pot Synthesis of Thiol-Modified Liquid Crystals Conjugated Fluorescent Gold Nanoclusters. NANOMATERIALS 2020; 10:nano10091755. [PMID: 32899952 PMCID: PMC7558681 DOI: 10.3390/nano10091755] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 09/02/2020] [Accepted: 09/04/2020] [Indexed: 11/16/2022]
Abstract
Gold nanoclusters (AuNCs) and liquid crystals (LCs) have shown great potential in nanobiotechnology applications due to their unique optical and structural properties. Herein, the hardcore of the 4-cyano biphenyl group for commonly used LCs of 4-cyano-4'-pentylbiphenyl (5CB) was utilized to synthesize 4'-(2-mercaptoethyl)-(1,1'-biphenyl)-4-carbonitrile (TAT-12) based on Suzuki coupling and Appel reaction. The structural and optical properties of thiol-modified TAT-12 LCs were demonstrated by nuclear magnetic resonance (NMR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy and differential scanning calorimetry (DSC). By one-pot synthesis, thiol-modified TAT-12 LCs were used as the ligands to prepare fluorescent gold nanoclusters (AuNCs@TAT-12) according to the Au-S bond between AuNCs and TAT-12. The spectra of UV-vis absorption and X-ray photoelectron spectroscopy (XPS) of AuNCs@TAT-12 indicated that the core of gold of AuNCs@TAT-12 exhibited high gold oxidation states. The fluorescence of AuNCs@TAT-12 was observed with a maximum intensity at ~352 nm coming from TAT-12 on AuNCs@TAT-12 and the fluorescence quantum yield of AuNCs@TAT-12 was calculated to be 10.1%. Furthermore, the fluorescence with a maximum intensity at ~448 nm was attributed to a ligand-metal charge transfer between the ligands of TAT-12 LCs and the core of AuNCs. The image of transmission electron microscopy (TEM) further demonstrated an approximately spherical shape of AuNCs@TAT-12 with an average size of 2.3 nm. A combination of UV-vis absorption spectra, XPS spectra, fluorescence spectra and TEM image, fluorescent AuNCs@TAT-12 were successfully synthesized via one-pot synthesis. Our work provides a practical approach to the synthesis of LCs conjugated AuNCs for future applications in nanobiotechnology.
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Affiliation(s)
- Po-Hsuan Hsu
- School of Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan; (P.-H.S.); (J.-C.K.)
| | - Sibidou Yougbaré
- International Ph.D. Program in Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan;
- Institut de Recherche en Sciences de la Santé (IRSS-DRCO), 03 B.P 7192, Ouagadougou 03, Nanoro, Burkina Faso
| | - Jui-Chi Kuo
- School of Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan; (P.-H.S.); (J.-C.K.)
| | | | - Achmad Jazidie
- Department of Electrical Engineering, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia;
- Nahdlatul Ulama Surabaya University, Surabaya 60111, Indonesia
| | - Mohammad Nuh
- Department of Biomedical Engineering, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia; or
| | - Po-Ting Chou
- Graduate Institute of Biomedical Optomechatronics, Taipei Medical University, Taipei 11031, Taiwan;
| | - Yu-Cheng Hsiao
- International Ph.D. Program in Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan;
- Graduate Institute of Biomedical Optomechatronics, Taipei Medical University, Taipei 11031, Taiwan;
- Correspondence: (Y.-C.H.); (T.-R.K.)
| | - Tsung-Rong Kuo
- International Ph.D. Program in Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan;
- Graduate Institute of Nanomedicine and Medical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan
- Correspondence: (Y.-C.H.); (T.-R.K.)
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12
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Electro-optical effects of organic N-benzyl-2-methyl-4-nitroaniline dispersion in nematic liquid crystals. Sci Rep 2020; 10:14273. [PMID: 32868860 PMCID: PMC7459335 DOI: 10.1038/s41598-020-71306-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 08/13/2020] [Indexed: 01/10/2023] Open
Abstract
The dispersion of organic N-benzyl-2-methyl-4-nitroaniline (BNA) in nematic liquid crystals (LCs) is studied. BNA doping decreases the threshold voltage of cell because of the reduced splay elastic constant and increased dielectric anisotropy of the LC mixture. When operated in the high voltage difference condition, the BNA-doped LC cell has a fall time that is five times faster than that of the pure one because of the decrements in the threshold voltage of the cell and rotational viscosity of the LC mixture. The additional restoring force induced by the BNA’s spontaneous polarization electric field (SPEF) also assists to decrease the fall time of the LC cell. The decreased viscosity can be deduced from the decrements in phase transition temperature and associated order parameter of the LC mixture. Density functional theory calculation demonstrates that the BNA dopant strengthens the absorbance for blue light, enhances the molecular interaction energy and dipole moment, decreases the molecular energy gap, and thus increases the permittivity of the LC mixture. The calculation also shows that the increased dipole moment, polarizability, and polarizability anisotropy increase the dielectric anisotropy of the LC mixture, which agrees with the experimental results well. BNA doping has a promising application to the fields of LC devices and displays.
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13
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Santos RD, Melo PD, Nunes A, Meneghetti M, Lyra M, Oliveira ID. Electro-optical switching in twisted nematic samples doped with gold nanorods. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.111704] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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14
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Elkhalgi HH, Khandka S, Yadav N, Dhar R, Dabrowski R. Effects of manganese (II) titanium oxide nano particles on the physical properties of a room temperature nematic liquid crystal 4-(trans-4′-n-hexylcyclohexyl) isothiocyanatobenzene. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.07.044] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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15
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Choudhary A, George TF, Li G. Conjugation of Nanomaterials and Nematic Liquid Crystals for Futuristic Applications and Biosensors. BIOSENSORS 2018; 8:E69. [PMID: 30011909 PMCID: PMC6165262 DOI: 10.3390/bios8030069] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 06/24/2018] [Accepted: 07/02/2018] [Indexed: 12/16/2022]
Abstract
The established role of nematic liquid crystals (NLCs) in the recent rapid development of displays has motivated researchers to modulate the electro-optical properties of LCs. Furthermore, adding nanomaterials into NLCs has led to enhancements of the properties of NLCs, like reduced threshold of the operating voltage, variation in pretilt angle, reduced switching time, etc. These enhanced properties, due to interfacial dynamics, are enabling wider applications of NLCs and nanomaterials. The recent literature of nanomaterial-doped NLCs is rich with various kinds of nanomaterials in a variety of NLCs. The light has been focused on the most widely used and studied gold nanoparticles in NLCs. The intrinsic inherent property of easy excitation of surface plasmons polaritons (SPP) is the mediating interaction of NLC electric dipoles and the polarization of charges in the GNP surface. The concepts and methods for the application of metal nanomaterials as dopants in NLCs are discussed for future applications, especially biosensors. The biosensing application of NLCs alone has already been proven in the literature. However, it is always desirable to further enhance the detection efficiency and selectivity, which have been achieved by the conjugation of GNPs and nickel nanoparticles with NLCs and their compatibility with biological materials. This aspect of future application of nanoparticles and NLC makes the point more selective to be included in the present manuscript.
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Affiliation(s)
- Amit Choudhary
- Department of Physics, Deshbandhu College, University of Delhi, Kalkaji, New Delhi 110019, India.
| | - Thomas F George
- Departments of Chemistry & Biochemistry and Physics & Astronomy, University of Missouri⁻St. Louis, St. Louis, MO 63121, USA.
| | - Guoqiang Li
- Visual and Biomedical Optics Lab, The Ohio State University, Columbus, OH 43212, USA.
- Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA.
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Ultra Uniform Pb 0.865La 0.09(Zr 0.65Ti 0.35)O₃ Thin Films with Tunable Optical Properties Fabricated via Pulsed Laser Deposition. MATERIALS 2018; 11:ma11040525. [PMID: 29596398 PMCID: PMC5951371 DOI: 10.3390/ma11040525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/27/2018] [Accepted: 03/28/2018] [Indexed: 11/17/2022]
Abstract
Ferroelectric thin films have been utilized in a wide range of electronic and optical applications, in which their morphologies and properties can be inherently tuned by a qualitative control during growth. In this work, we demonstrate the evolution of the Pb0.865La0.09(Zr0.65Ti0.35)O3 (PLZT) thin films on MgO (200) with high uniformity and optimized optical property via the controls of the deposition temperatures and oxygen pressures. The perovskite phase can only be obtained at the deposition temperature above 700 °C and oxygen pressure over 50 Pa due to the improved crystallinity. Meanwhile, the surface morphologies gradually become smooth and compact owing to spontaneously increased nucleation sites with the elevated temperatures, and the crystallization of PLZT thin films also sensitively respond to the oxygen vacancies with the variation of oxygen pressures. Correspondingly, the refractive indices gradually develop with variations of the deposition temperatures and oxygen pressures resulted from the various slight loss, and the extinction coefficient for each sample is similarly near to zero due to the relatively smooth morphology. The resulting PLZT thin films exhibit the ferroelectricity, and the dielectric constant sensitively varies as a function of electric filed, which can be potentially applied in the electronic and optical applications.
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17
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Emdadi M, Poursamad JB, Sahrai M, Moghaddas F. Behaviour of nematic liquid crystals doped with ferroelectric nanoparticles in the presence of an electric field. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1441462] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- M. Emdadi
- Department of Laser and Optical Engineering, University of Bonab, Bonab, Iran
| | - J. B. Poursamad
- Department of Laser and Optical Engineering, University of Bonab, Bonab, Iran
| | - M. Sahrai
- Research Institute for Applied Physics and Astronomy, University of Tabriz, Tabriz, Iran
| | - F. Moghaddas
- Department of Laser and Optical Engineering, University of Bonab, Bonab, Iran
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Kumar P, Debnath S, Rao NVS, Sinha A. Nanodoping: a route for enhancing electro-optic performance of bent core nematic system. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:095101. [PMID: 29336349 DOI: 10.1088/1361-648x/aaa801] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report the effect of dispersion of barium titanate (BaTiO3) nanoparticles (BNPs) in a four ring bent core nematic (BCN) liquid crystal. Polarizing optical microscopy reveals the presence of a single nematic phase in pure and doped states. Polar switching has been observed in the bent core system and the value of spontaneous polarization (P s) increases with increase in doping concentration of BNPs in BCN. Dielectric study shows a lower frequency mode, which can be ascribed to the formation of cybotactic clusters. These clusters are also responsible for the observed polar switching in pure, as well as, in doped BCNs. Another higher frequency mode, observed only in pure BCN, indicates the rotation of molecules about their long molecular axis. The conductivity of doped samples is also found to decrease as compared to the pure BCN. This reduction helps in the minimization of negative effects caused by free ions in liquid crystal based devices. This study demonstrates that the interaction between BNPs and BCN molecules improves the P s, dielectric behaviour, viscosity and reduces the conductivity of pure BCN. Hence, nanodoping in a BCN is an effective method for the enhancement of electro-optic performances and will lead to the development of faster electro-optic devices.
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Affiliation(s)
- Pradeep Kumar
- Department of Physics, Indian Institute of Technology Delhi, 110016, India
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19
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Shcherbinin DP, Konshina EA. Impact of titanium dioxide nanoparticles on purification and contamination of nematic liquid crystals. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2017; 8:2766-2770. [PMID: 29354347 PMCID: PMC5753047 DOI: 10.3762/bjnano.8.275] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 11/08/2017] [Indexed: 06/07/2023]
Abstract
We have investigated the impact of titanium dioxide nanoparticles on the ionic contamination of liquid crystals. Nematic liquid crystals with high and low initial ionic contamination have been examined. It has been shown that titanium dioxide nanoparticles reduced the ion density of liquid crystals with high initial ionic contamination from 134.5 × 1012 cm-3 to 63.2 × 1012 cm-3. In the case of liquid crystals with low initial ionic contamination, the nanoparticles led to an insignificant increase of ion density from 19.8 × 1012 cm-3 to 25.7 × 1012 cm-3.
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Affiliation(s)
- Dmitrii Pavlovich Shcherbinin
- Department of Optical Physics and Modern Natural Science, ITMO University, Kronverkskiy pr. 49, Saint Petersburg 197101, Russia
| | - Elena A Konshina
- Department of Optical Physics and Modern Natural Science, ITMO University, Kronverkskiy pr. 49, Saint Petersburg 197101, Russia
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Garbovskiy Y, Glushchenko A. Ferroelectric Nanoparticles in Liquid Crystals: Recent Progress and Current Challenges. NANOMATERIALS 2017; 7:nano7110361. [PMID: 29104276 PMCID: PMC5707578 DOI: 10.3390/nano7110361] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 10/24/2017] [Accepted: 10/24/2017] [Indexed: 12/21/2022]
Abstract
The dispersion of ferroelectric nanomaterials in liquid crystals has recently emerged as a promising way for the design of advanced and tunable electro-optical materials. The goal of this paper is a broad overview of the current technology, basic physical properties, and applications of ferroelectric nanoparticle/liquid crystal colloids. By compiling a great variety of experimental data and discussing it in the framework of existing theoretical models, both scientific and technological challenges of this rapidly developing field of liquid crystal nanoscience are identified. They can be broadly categorized into the following groups: (i) the control of the size, shape, and the ferroelectricity of nanoparticles; (ii) the production of a stable and aggregate-free dispersion of relatively small (~10 nm) ferroelectric nanoparticles in liquid crystals; (iii) the selection of liquid crystal materials the most suitable for the dispersion of nanoparticles; (iv) the choice of appropriate experimental procedures and control measurements to characterize liquid crystals doped with ferroelectric nanoparticles; and (v) the development and/or modification of theoretical and computational models to account for the complexity of the system under study. Possible ways to overcome the identified challenges along with future research directions are also discussed.
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Affiliation(s)
- Yuriy Garbovskiy
- UCCS Biofrontiers Center and Department of Physics, University of Colorado Colorado Springs, Colorado Springs, CO 80918, USA.
| | - Anatoliy Glushchenko
- Department of Physics, University of Colorado Colorado Springs, Colorado Springs, CO 80918, USA.
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Rzoska SJ, Starzonek S, Drozd-Rzoska A, Czupryński K, Chmiel K, Gaura G, Michulec A, Szczypek B, Walas W. Impact of BaTiO(3) nanoparticles on pretransitional effects in liquid crystalline dodecylcyanobiphenyl. Phys Rev E 2016; 93:020701. [PMID: 26986276 DOI: 10.1103/physreve.93.020701] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Indexed: 11/07/2022]
Abstract
The pretransitional behavior of dodecylcyanobiphenyl (12CB) (isotropic-smectic-A-solid mesomorphism) with d=50nmBaTiO(3) nanoparticles (NPs) linked to the cubic phase was monitored via temperature studies of dielectric constant. Tests were carried out in the isotropic, liquid crystal mesomorphic, and solid phases. For each phase transition the same value of the critical exponent α∼0.5 was obtained, including nanocolloids. All phase transitions show the weakly discontinuous nature. The temperature metric of the discontinuity ΔT notably decreases when adding nanoparticles. The addition of nanoparticles first decreases the dielectric constant by approximately 50% in comparison with pure 12CB, but already for a concentration ∼x=0.4% NP an increase over 50% takes place. It is notable that for the latter concentration unique hallmarks of the pretransitional effect emerge also for the solid-mesophase transition. All these indicate the important impact of nanoparticles on multimolecular mesoscale fluctuations.
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Affiliation(s)
- S J Rzoska
- Silesian Intercollegiate Centre for Education and Interdisciplinary Research & Institute of Physics, University of Silesia, ulica 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.,Institute of High Pressure Physics, Polish Academy of Sciences, ulica Sokołowska 29/37, 01-142 Warsaw, Poland
| | - S Starzonek
- Silesian Intercollegiate Centre for Education and Interdisciplinary Research & Institute of Physics, University of Silesia, ulica 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.,Institute of High Pressure Physics, Polish Academy of Sciences, ulica Sokołowska 29/37, 01-142 Warsaw, Poland
| | - A Drozd-Rzoska
- Institute of High Pressure Physics, Polish Academy of Sciences, ulica Sokołowska 29/37, 01-142 Warsaw, Poland
| | - K Czupryński
- Military University of Technology, Institute of Chemistry, ulica Kaliskiego 2, 00-908 Warsaw, Poland
| | - K Chmiel
- Silesian Intercollegiate Centre for Education and Interdisciplinary Research & Institute of Physics, University of Silesia, ulica 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - G Gaura
- Silesian Intercollegiate Centre for Education and Interdisciplinary Research & Institute of Physics, University of Silesia, ulica 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - A Michulec
- Silesian Intercollegiate Centre for Education and Interdisciplinary Research & Institute of Physics, University of Silesia, ulica 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - B Szczypek
- Silesian Intercollegiate Centre for Education and Interdisciplinary Research & Institute of Physics, University of Silesia, ulica 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - W Walas
- Silesian Intercollegiate Centre for Education and Interdisciplinary Research & Institute of Physics, University of Silesia, ulica 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
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Verma KC, Kotnala RK. Tailoring the multiferroic behavior in BiFeO3 nanostructures by Pb doping. RSC Adv 2016. [DOI: 10.1039/c6ra12949h] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Substituting Pb2+ for Bi3+ in BiFeO3 can induce lattice distortions and structural transitions to tune the lone-pair activity for ferroelectricity and neutralized oxygen vacancies to valence Fe2+/Fe3+ ions for ferromagnetism.
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Affiliation(s)
- Kuldeep Chand Verma
- Centre of Advanced Study in Physics
- Department of Physics
- Panjab University
- Chandigarh 160 014
- India
| | - R. K. Kotnala
- CSIR-National Physical Laboratory
- New Delhi 110012
- India
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