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Singh PK, Dhar R, Dabrowski R. Enhancement of dielectric and electro-optical characteristics of liquid crystalline material 4'-octyl-4-cyano-biphenyl with dispersed functionalized and nonfunctionalized multiwalled carbon nanotubes. Phys Rev E 2023; 107:044704. [PMID: 37198864 DOI: 10.1103/physreve.107.044704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 03/01/2023] [Indexed: 05/19/2023]
Abstract
For recent applications, liquid crystal-carbon nanotube based nanocomposite systems have been proven to be highly attractive. In this paper, we give a thorough analysis of a nanocomposite system made of both functionalized and nonfunctionalized multiwalled carbon nanotubes that are disseminated in a 4'-octyl-4-cyano-biphenyl liquid crystal medium. Thermodynamic study reveals a decrease in the nanocomposites' transition temperatures. In contrast to nonfunctionalized multiwalled carbon nanotube dispersed systems, the enthalpy of functionalized multiwalled carbon nanotube dispersed systems has increased. In comparison to the pure sample, the dispersed nanocomposites have a smaller optical band gap. A rise in the longitudinal component of permittivity and, consequently, the dielectric anisotropy of the dispersed nanocomposites has been observed by dielectric studies. When compared to the pure sample, the conductivity of both dispersed nanocomposite materials has increased by two orders of magnitude. For the system with dispersed functionalized multiwalled carbon nanotubes, the threshold voltage, splay elastic constant, and rotational viscosity all decreased. For the dispersed nanocomposite of nonfunctionalized multiwalled carbon nanotubes, the value of the threshold voltage is somewhat decreased but the rotational viscosity and splay elastic constant both are enhanced. These findings show the applicability of the liquid crystal nanocomposites for display and electro-optical systems with appropriate tuning of the parameters.
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Affiliation(s)
- Praveen Kumar Singh
- Centre of Material Sciences, University of Allahabad, Prayagraj-211002, India
| | - Ravindra Dhar
- Centre of Material Sciences, University of Allahabad, Prayagraj-211002, India
| | - Roman Dabrowski
- Institute of Applied Sciences and Chemistry, Military University of Technology, Warsaw 00-908, Poland
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Kurilov AD, Chausov DN, Osipova VV, Sagdeev DO, Chekulaev IS, Kucherov RN, Belyaev VV, Galyametdinov YG. Concentration-dependent dielectric and electro-optical properties of composites based on nematic liquid crystals and CdS:Mn quantum dots. SOFT MATTER 2023; 19:2110-2119. [PMID: 36857700 DOI: 10.1039/d2sm01352e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Composites in a wide concentration range of 0-0.6 wt% based on a nematic liquid crystal mixture and CdS quantum dots doped with manganese ions (Mn 6%) are presented. The effect of the CdS:Mn quantum dots on the phase diagram and electronic structure of composites was studied using differential scanning calorimetry and fluorescence analysis. Nonmonotonic concentration-dependent changes in the clearing point, which correlate with the fluorescence quenching behavior of the main CdS:Mn peak, were found. Dielectric spectroscopy and electro-optic studies revealed a corresponding increase in the dielectric permittivity anisotropy and birefringence in the 0.2-0.4 wt% range, where thermodynamic changes occur. The initiating factors behind this effect are supposed to be the self-assembly of quantum dots, and the distortion of the orientation order of liquid crystal molecules at a higher mass concentration of quantum dots.
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Affiliation(s)
- Alexander D Kurilov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St, Moscow, 119991, Russia.
- Moscow Region State University, 24 Very Voloshinoy St., 141014, Mytishchi, Russia
| | - Denis N Chausov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St, Moscow, 119991, Russia.
- Moscow University for Industry and Finance "Synergy", 2 Izmailovsky Val St., Moscow, 105318, Russia
| | - Valentina V Osipova
- Kazan National Research Technological University, 68 K. Marx St., 420015, Kazan, Russia
| | - Dmitriy O Sagdeev
- Kazan National Research Technological University, 68 K. Marx St., 420015, Kazan, Russia
| | - Igor S Chekulaev
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St, Moscow, 119991, Russia.
- Moscow Region State University, 24 Very Voloshinoy St., 141014, Mytishchi, Russia
| | - Roman N Kucherov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St, Moscow, 119991, Russia.
- Moscow Region State University, 24 Very Voloshinoy St., 141014, Mytishchi, Russia
| | - Victor V Belyaev
- Moscow Region State University, 24 Very Voloshinoy St., 141014, Mytishchi, Russia
| | - Yuriy G Galyametdinov
- Kazan National Research Technological University, 68 K. Marx St., 420015, Kazan, Russia
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3
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Ostovari F, Dehghani Z. Influence of aminated graphene nanosheets on electro–optical performance and nonlinear optical properties of nematic liquid crystal. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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4
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Selvaraj P, Lo PC, Hsu MH, Antony M, Hsu CJ, Huang CY. Impact of terminal group of organic dopant on liquid crystal-based electro-optic device. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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5
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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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Rani A, Chakraborty S, Sinha A. Effect of CdSe/ZnS quantum dots doping on the ion transport behavior in nematic liquid crystal. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117327] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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7
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A stokes polarimetric light microscopy view of liquid crystal droplets. Sci Rep 2021; 11:16329. [PMID: 34381082 PMCID: PMC8358033 DOI: 10.1038/s41598-021-95674-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 07/26/2021] [Indexed: 11/08/2022] Open
Abstract
The optical characteristics of materials, such as their magnetooptical effects, birefringence, optical activities, linear and circular dichroism, are probed via the polarisation states of light transmitted through or reflected from the specimens. As such, the measurements of the polarisation states play an important role in many research disciplines. Experimentally, Stokes parameters provide a full description of the polarisation states of light. We report the implementation of a dual- photoelastic modulator based polarimeter in a light microscope, enabling the determination of Stokes parameters at each pixel. As a case study, polarimetric images of liquid crystal droplets of different internal structures are obtained, showing their distinct polarisation characteristics. We demonstrate that the prototype Stokes polarimetric microscope allows the quantitative determination of the polarisation characteristics of light at the object plane and enables the access of the information of full polarisation states as compared to a conventional cross polariser microscope. This work shows that Stokes polarimetric microscopy may find potential applications in a wide range of research fields.
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Dong J, Fang W, Xia W, Lu Q, Zeng X. Facile preparation of Zn x Cd 1-x S/ZnS heterostructures with enhanced photocatalytic hydrogen evolution under visible light. RSC Adv 2021; 11:21642-21650. [PMID: 35478814 PMCID: PMC9034141 DOI: 10.1039/d1ra03195c] [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: 04/24/2021] [Accepted: 06/13/2021] [Indexed: 11/21/2022] Open
Abstract
Hydrogen evolution from water using solar energy is regarded as a most promising process, thus, exploring efficient photocatalysts for water splitting is highly desirable. To avoid the rapid recombination of photogenerated electrons and holes in CdZnS semiconductors, ZnxCd1−xS/ZnS composites were synthesized via a one-step hydrothermal method and then annealed at 400 °C for 60 min under argon flow. ZnxCd1−xS/ZnS composites are composed of ZnS nanosheets decorated with ZnxCd1−xS nanorods, and TEM and UV-vis absorption spectra confirm the formation of the heterostructure between ZnxCd1−xS nanorods and ZnS nanosheets. Because of the well-matched band alignment, stronger optical absorption and larger carrier density, Zn0.2Cd0.8S/ZnS has the highest hydrogen production, with a photocatalytic hydrogen production rate up to 16.7 mmol g−1 h−1 under visible light irradiation. Moreover, the photocatalyst also exhibits high stability and good reusability for hydrogen production reaction. The facile and efficient approach for ZnS based heterostructures could be extended to other metal compound materials. Schematic illustration for electron charge transfer and H2 evolution mechanism for the Zn0.2Cd0.8S/ZnS nanocomposites.![]()
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Affiliation(s)
- Jing Dong
- College of Chemistry and Chemical Engineering, Yangzhou University Yangzhou 225002 P. R. China
| | - Wenjian Fang
- College of Electrical, Energy and Power Engineering, Yangzhou University Yangzhou 225127 P. R. China
| | - Weiwei Xia
- College of Physics Science and Technology & Institute of Optoelectronic Technology, Yangzhou University Yangzhou 225002 P. R. China
| | - Qihong Lu
- College of Physics Science and Technology & Institute of Optoelectronic Technology, Yangzhou University Yangzhou 225002 P. R. China
| | - Xianghua Zeng
- College of Electrical, Energy and Power Engineering, Yangzhou University Yangzhou 225127 P. R. China .,College of Physics Science and Technology & Institute of Optoelectronic Technology, Yangzhou University Yangzhou 225002 P. R. China
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Garbovskiy Y. Conventional and unconventional ionic phenomena in tunable soft materials made of liquid crystals and nanoparticles. NANO EXPRESS 2021. [DOI: 10.1088/2632-959x/abe652] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
A great variety of tunable multifunctional materials can be produced by combining nanoparticles and liquid crystals. Typically, the tunability of such soft nanocomposites is achieved via external electric fields resulting in the field-induced reorientation of liquid crystals. This reorientation can be altered by ions normally present in liquid crystals in small quantities. In addition, nanomaterials dispersed in liquid crystals can also affect the behavior of ions. Therefore, an understanding of ionic phenomena in liquid crystals doped with nanoparticles is essential for future advances in liquid crystal-aided nanoscience and nanotechnology. This paper provides an overview of the ionic effects observed in liquid crystals doped with nanomaterials. An introduction to liquid crystals is followed by a brief overview of nanomaterials in liquid crystals. After giving a basic description of ions in liquid crystals and experimental methods to measure them, a wide range of ionic phenomena in liquid crystals doped with different types of nanomaterials is discussed. After that, both existing and emerging applications of tunable soft materials made of liquid crystals and nanodopants are presented with an emphasis on the role of ionic effects in such systems. Finally, the discussion of unsolved problems and future research directions completes the review.
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