Doping of nematic cyanobiphenyl liquid crystals with mesogen-hybridized magnetic nanoparticles

2017 ◽  
Vol 19 (19) ◽  
pp. 12127-12135 ◽  
Author(s):  
Ingo Appel ◽  
Hajnalka Nádasi ◽  
Christian Reitz ◽  
Nerea Sebastián ◽  
Horst Hahn ◽  
...  
Keyword(s):  
Optical Properties ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Magnetic Nanoparticles ◽  
Magnetic Nanoparticle ◽  
Surface Engineering

Surface engineering of magnetic nanoparticles with (pro-)mesogenic ligands leads to colloidally stable magnetic nanoparticle–liquid crystal hybrids with interesting magneto-optical properties.

scholarly journals Steady-state rheology and structure of soft hybrid mixtures of liquid crystals and magnetic nanoparticles

Soft Matter ◽  
2020 ◽  
Vol 16 (10) ◽  
pp. 2516-2527
Author(s):  
Gaurav P. Shrivastav ◽  
Nima H. Siboni ◽  
Sabine H. L. Klapp
Keyword(s):  
Liquid Crystal ◽  
Steady State ◽  
Liquid Crystals ◽  
Magnetic Nanoparticles ◽  
Magnetic Nanoparticle ◽  
Dipolar Coupling ◽  
Hybrid Mixtures

The rhology of liquid crystal–magnetic nanoparticle mixtures is strongly dependent on the strength of the dipolar coupling among the magnetic nanoparticles.

BIREFRINGENCE AND MAGNETO-OPTICAL PROPERTIES IN OLEIC ACID COATED Fe3O4 NANOPARTICLES: APPLICATION FOR OPTICAL SWITCH

2011 ◽  
Vol 10 (03) ◽  
pp. 515-520 ◽  
Author(s):  
SI-HUA XIA ◽  
JUN WANG ◽  
ZHANG-XIAN LU ◽  
FEIYAN ZHANG
Keyword(s):  
Magnetic Field ◽  
Optical Properties ◽  
Oleic Acid ◽  
Magnetic Nanoparticles ◽  
Magnetic Nanoparticle ◽  
Optical Switch ◽  
Colloidal Suspension ◽  
Experimental Parameters ◽  
Nanoparticle Chains ◽  
The Magnetic Field

We report magneto-optical properties in a kerosene colloidal suspension of oleic acid coated Fe3O4 nanoparticles (~14 nm). The magnetic colloids (fluids) show birefringence under a magnetic field. Systematical studies of the on–off switch times upon application of the on–off magnetic field with varied experimental parameters indicate that the switch response time depends strongly on the strength of the magnetic field and the concentration of the magnetic nanoparticles in the fluid. The data can be explained in terms of the formation of magnetic nanoparticle chains under a magnetic field. The important magneto-optical properties of the magnetic fluids allow us to design a tunable optical switch.

Textural Spectral Characteristics of the Cholesteric Liquid Crystal

2010 ◽  
Vol 428-429 ◽  
pp. 241-246
Author(s):  
Jia Ling Wang ◽  
Xin Du ◽  
Jia Lv ◽  
Tian Chi Yu ◽  
Zhi Xin Fan
Keyword(s):  
Optical Properties ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Cholesteric Liquid Crystal ◽  
Spectral Characteristics ◽  
Optoelectronic Devices ◽  
Liquid Crystal Displays ◽  
Transmission Property ◽  
Large Crystal ◽  
Important Significance

For the cholesteric liquid crystal (hereinafter short for Ch-LC) possesses special optical properties, it has specific applications in the area of liquid crystal displays and optoelectronic devices. Specimens of Ch-LCs in planar and focal conic texture stably are prepared. The photographs of textures are shot by polarizing microscope and transmittance spectrums of different textures are measured by spectrophotometer. It is found that the specimen in focal conic texture with large crystal domains has the well transmission property. The experiment has an important significance for applications of liquid crystals.

scholarly journals Study of Structural Changes in Nematic Liquid Crystals Doped with Magnetic Nanoparticles Using Surface Acoustic Waves

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1023
Author(s):  
Peter Bury ◽  
Marek Veveričík ◽  
František Černobila ◽  
Peter Kopčanský ◽  
Milan Timko ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Magnetic Nanoparticles ◽  
Electric Fields ◽  
Acoustic Waves ◽  
Structural Changes ◽  
Surface Acoustic Waves ◽  
Theoretical Background ◽  
Isotropic Phase ◽  
Structure Of Nanoparticles

The surface acoustic waves (SAWs) were used to study the effect of magnetic nanoparticles on nematic liquid crystal (NLC) behavior in weak magnetic and electric fields. The measurement of the attenuation of SAW propagating along the interface between piezoelectric substrate and liquid crystal is showed as an effective tool to study processes of structural changes. The magnetic nanoparticles Fe3O4 of nanorod shape and different low volume concentration were added to the NLC (4-(trans-4′-n-hexylcyclohexyl)-isothiocyanatobenzene (6CHBT)) during its isotropic phase. In contrast to undoped liquid crystals the distinctive different SAW attenuation responses induced by both magnetic and also electric fields in studied NLC samples were observed suggesting both structural changes and the orientational coupling between both magnetic and electric moments of nanoparticles and the director of the NLC molecules. Experimental measurements including the investigation under linearly increasing and/or jumped magnetic and electrical fields, respectively, as well as the investigation of temperature and time influences on structural changes were done. The investigation of the SAW anisotropy gives supplemental information about the internal structure of nanoparticles in investigated NLCs. In addition, some magneto-optical investigations were performed to support SAW results and study their stability and switching time. The analysis of observed SAW attenuation characteristics confirmed the role of concentration of magnetic nanoparticles on the resultant behavior of investigated NLC compounds. Obtained results are discussed within the context of previous ones. The theoretical background of the presented SAW investigation is introduced, too.

Research on Non-Electric Readout Infrared Thermal Imaging Detection Technology Based on the Liquid Crystal

2011 ◽  
Vol 181-182 ◽  
pp. 293-296
Author(s):  
Chang Long Cai ◽  
Ya Zhang ◽  
Xiao Ling Niu ◽  
Wei Guo Liu
Keyword(s):  
Optical Properties ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Thermal Imaging ◽  
Optical Rotation ◽  
Cholesteric Liquid Crystals ◽  
Isotropic Liquid ◽  
Infrared Thermal Imaging ◽  
Detection Technology ◽  
Imaging Detection

Liquid crystal, as a condensed matter, is a phase state between crystal and isotropic liquid. On the one hand, it has mobility and continuity as a liquid, and on the other hand, it has arranging ordering as a crystal, then it has many unique properties. Because the factors, such as heat, electric field, magnetic field, pressure, and so on, will easily influence the arranging of liquid crystal molecular, so once it is excited externally, its optical properties will be changed. At present, most research on the theory and application of liquid crystal mainly focus on the display. Thermo-optic effect is defined as the phenomenon that the optical properties of liquid crystal change with the changing of temperature. At the phase transition point, the thermo-optic effect of liquid crystal is very obvious. In this paper, non-electric readout infrared thermal imaging detection technology based on the optical rotation property of the cholesteric liquid crystals is mainly researched. Through the research, the cholesteric liquid crystals’ light curves, gray value curves and CCD image were obtained under different temperatures; it proved that using the optical rotation property of cholesteric liquid crystals to achieve the infrared imaging of hot objects is possible.

scholarly journals Frequency dependence of electric field tunability in a photonic liquid crystal fiber based on gold nanoparticles-doped 6CHBT nematic liquid crystal

2020 ◽  
Vol 12 (4) ◽  
pp. 115
Author(s):  
Miłosz Chychłowski ◽  
Tomasz Woliński
Keyword(s):  
Gold Nanoparticles ◽  
Optical Properties ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Photonic Crystal ◽  
Electric Field ◽  
External Electric Field ◽  
Photonic Crystal Fibers ◽  
Crystal Fiber ◽  
Crystal Fibers

In this paper, we investigate an external electric field frequency influence on a photonic liquid crystal fiber (PLCF) based on a gold nanoparticles (NPs)-doped nematic liquid crystal (LC) and its response to the external electric field. We used a 6CHBT nematic LC doped with 2-nm gold NPs in a weight concentration of 0.1%, 0.2%, 0.3%, and 0.5%. Full Text: PDF ReferencesJ. C. Knight, T. A. Birks, P. St. J. Russell, and D. M. Atkin, "All-silica single-mode optical fiber with photonic crystal cladding," Opt. Lett. 21, 1547-1549 (1996) CrossRef J. C. Knight,T. A. Birks, P. S. J.Russell, , and J. P. De Sandro, "Properties of photonic crystal fiber and the effective index model", JOSA A, 15(3), 748-752, (1998) CrossRef S. A. Cerqueira,F. Luan, C. M. B. Cordeiro, A. K. George, and J. C. Knight, "Hybrid photonic crystal fiber", "Optics Express", 14(2), 926-931,(2006) CrossRef W. Bragg, "Liquid Crystals", Nature 133, 445-456, (1934) https://doi.org/10.1038/133445a0 CrossRef J. Kędzierski, K. Garbat, Z. Raszewski, M. Kojdecki, K. Kowiorski, L. Jaroszewicz, and W. Piecek, "Optical properties of a liquid crystal with small ordinary and extraordinary refractive indices and small optical anisotropy", Opto-Electronics Review, 22(3), 162-165, (2014) CrossRef Y. Li, and S. T. Wu, "Polarization independent adaptive microlens with a blue-phase liquid crystal", Optics express, 19(9), 8045-8050, (2011) CrossRef T. Woliński, S. Ertman, K. Rutkowska, D. Budaszewski, M. Sala-Tefelska, M. Chychłowski, K. Orzechowski, K. Bednarska, P. Lesiak, "Photonic Liquid Crystal Fibers - 15 years of research activities at Warsaw University of Technology", Phot. Lett. Pol., (11), (2), 22-24, (2019) https://doi.org/10.4302/plp.v11i2.907. CrossRef T.T. Larsen, A. Bjraklev, D.S. Hermann, J. Broeng, Opt. Expr. 11(20), 2589, (2003) CrossRef T.R. Woliński, K. Szaniawska, K. Bondarczuk, P. Lesiak, A.W. Domański, R. Dąbrowski, E. Nowinowski-Kruszelnicki, J. Wójcik, "Propagation properties of photonic crystal fibers filled with nematic liquid crystals", Opto-Electron. Rev. 13(2), 59 (2005) DirectLink L. Scolari, S. Gauza, H. Xianyu, L. Zhai, L. Eskildsen, T. T. Alkeskjold, S.-T. Wu, and A. Bjarklev, "Frequency tunability of solid-core photonic crystal fibers filled with nanoparticle-doped liquid crystals," Opt. Express 17(5), 3754-3764 (2009). CrossRef A. Siarkowska, M. Chychłowski, D. Budaszewski, B. Jankiewicz, B. Bartosewicz, and T. R. Woliński, "Thermo-and electro-optical properties of photonic liquid crystal fibers doped with gold nanoparticles", Beilstein Journal of Nanotechnology, 8(1), 2790-2801, (2017) CrossRef D. Budaszewski, M. Chychłowski, A. Budaszewska, B. Bartosewicz, B. Jankiewicz, and T. R. Woliński, "Enhanced efficiency of electric field tunability in photonic liquid crystal fibers doped with gold nanoparticles", Optics express, 27(10), 14260-14269, (2019) CrossRef D. Budaszewski, A. Siarkowska, M. Chychłowski, B. Jankiewicz, B. Bartosewicz, R. Dąbrowski, T. R. Woliński, "Nanoparticles-enhanced photonic liquid crystal fibers", Journal of Molecular Liquids, 267, 271-278, (2018) CrossRef

Acetone Sensing Based on Transmittance of Hydroxyethyl Methacrylate-Liquid Crystal Materials

2020 ◽  
Vol 840 ◽  
pp. 424-429
Author(s):  
Harry Miyosi Silalahi ◽  
Wei Fan Chiang ◽  
Chia Yi Huang
Keyword(s):  
Optical Properties ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Cholesteric Liquid Crystal ◽  
Thickness Effect ◽  
Helical Axis ◽  
Hydroxyethyl Methacrylate ◽  
Absorption Process ◽  
Natural Property ◽  
Mixture Concentration

Poly hydroxyethyl methacrylate (p-HEMA) has a natural property that is very easy to absorb a liquid or solution and become a hydrogel when absorbing water. In this work, by combining p-HEMA material with a cholesteric liquid crystal (CLC), the material can absorb the solution and the optical properties of the liquid crystal will change depending on the solution it absorbs. The solution used in this work is acetone. During the absorption process the p-HEMA material expanded so that the orientation direction of liquid crystal molecular twist with a helical axis along can freely move and change. In this work, we observed the study of transmittance caused by thickness effect and the mixture concentration effect of the poly hydroxyethyl methacrylate liquid crystals (PHM-LC).

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