Studies of dispersed liquid crystals in binary mixtures with ionic liquid and their excitation by electric signals

RSC Advances ◽  
2015 ◽  
Vol 5 (105) ◽  
pp. 86291-86302 ◽  
Author(s):  
Jagdeesh Kumar Srivastava ◽  
Rajendra Kumar Singh ◽  
Ravindra Dhar ◽  
Shri Singh
Keyword(s):  
Ionic Liquid ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Binary Mixtures ◽  
Nematic Liquid Crystal ◽  
Morphological Changes ◽  
Electric Signals

Morphological changes observed in the binary mixtures of nematic liquid crystal and ionic liquid with externally applied electric signals.

New structure induced by elastic anisotropy in cylindrical nematic liquid crystal

2017 ◽  
Vol 13 (2) ◽  
pp. 4705-4717
Author(s):  
Zhang Qian ◽  
Zhou Xuan ◽  
Zhang Zhidong
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Nematic Liquid Crystal ◽  
Elastic Anisotropy ◽  
Nematic Liquid Crystals ◽  
Gennes Theory

Basing on Landau–de Gennes theory, this study investigated the chiral configurations of nematic liquid crystals confined to cylindrical capillaries with homeotropic anchoring on the cylinder walls. When the elastic anisotropy (L2/L1) is large enough, a new structure results from the convergence of two opposite escape directions of the heterochiral twist and escape radial (TER) configurations. The new defect presents when L2/L1≥7 and disappears when L2/L1<7. The new structure possesses a heterochiral hyperbolic defect at the center and two homochiral radial defects on both sides. The two radial defects show different chiralities.

scholarly journals Regularity Criterion for the 3D Nematic Liquid Crystal Flows

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Jishan Fan ◽  
Tohru Ozawa
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Nematic Liquid Crystal ◽  
Regularity Criterion ◽  
Hydrodynamic Theory ◽  
Nematic Liquid Crystal Flows

We study the hydrodynamic theory of liquid crystals. We prove a logarithmically improved regularity criterion for two simplified Ericksen-Leslie systems.

scholarly journals 1-(4-Alkyloxybenzyl)-3-methyl-1H-imidazol-3-ium organic backbone: A versatile smectogenic moiety

2009 ◽  
Vol 5 ◽  
Author(s):  
William Dobbs ◽  
Laurent Douce ◽  
Benoît Heinrich
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Common Element ◽  
Crystal Fields ◽  
Single Compound ◽  
Imidazolium Ring ◽  
Mesomorphic Properties

The merger of ionic liquid and liquid crystal fields, obtained by using the imidazolium ring as a common element, has allowed us to tailor a new set of materials which associate specific functionalities. These functionalities are consequences of the original properties of the component, ionic liquids, liquid crystals and their association in a single compound. The study of this interesting association led us to elaborate environment-flexible cationic architectures from which mesomorphic properties emerge. Moreover, we have also explored the influence of different anions on the mesomorphic properties.

Synthesis and thermotropic properties of new green electrochromic ionic liquid crystals

2019 ◽  
Vol 43 (46) ◽  
pp. 18285-18293 ◽  
Author(s):  
Lucia Veltri ◽  
Gabriella Cavallo ◽  
Amerigo Beneduci ◽  
Pierangelo Metrangolo ◽  
Giuseppina Anna Corrente ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Small Molecules ◽  
Ionic Liquid Crystals ◽  
Thermotropic Properties

New liquid crystal viologens, which exhibit green electrochromic behavior in the LC phase, rarely observed for small molecules, have been developed.

The breathers in nematic liquid crystals under applied electric field

2019 ◽  
Vol 33 (26) ◽  
pp. 1950319
Author(s):  
Yan Li ◽  
Xiaobo Lu ◽  
Chunfeng Hou
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Electric Field ◽  
Nematic Liquid Crystal ◽  
Dynamic Equation ◽  
Applied Electric Field ◽  
Deflection Angle ◽  
Breather Solution ◽  
The Relationship ◽  
Sg Equation

In this paper, we study the twist of the nematic liquid crystal molecules under the applied electric field. The dynamic equation of the twisted molecules is derived. It is proved to be a kind of sine-Gordon (SG) equation. We obtain the breather solution of the equation and confirm that the deflection angles of the twisted molecules can distribute in the form of breathers. We give the relationship between the molecular deflection angle and the breather frequency, and discuss the effect of electric field on breather shape and breather frequency.

Surface-Functionalized Ionic Liquid Crystal-Supported Ionic Liquid Phase Materials: Ionic Liquid Crystals in Mesopores

ChemPhysChem ◽  
2011 ◽  
Vol 12 (18) ◽  
pp. 3539-3546 ◽  
Author(s):  
Florian T. U. Kohler ◽  
Bruno Morain ◽  
Alexander Weiß ◽  
Mathias Laurin ◽  
Jörg Libuda ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Liquid Phase ◽  
Functionalized Ionic Liquid ◽  
Supported Ionic Liquid ◽  
Ionic Liquid Crystals

Orientation, interaction and laser assisted self-assembly of organic single-crystal micro-sheets in a nematic liquid crystal

Soft Matter ◽  
2015 ◽  
Vol 11 (38) ◽  
pp. 7674-7679 ◽  
Author(s):  
M. V. Rasna ◽  
K. P. Zuhail ◽  
U. V. Ramudu ◽  
R. Chandrasekar ◽  
J. Dontabhaktuni ◽  
...  
Keyword(s):  
Experimental Study ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Single Crystal ◽  
Nematic Liquid Crystal ◽  
Self Assembly ◽  
Nematic Liquid Crystals ◽  
Directed Assembly ◽  
Orientation Interaction ◽  
Organic Single Crystal

In this paper we report first experimental study on the orientation, interaction and directed-assembly of single crystal micro-sheets in nematic liquid crystals.

scholarly journals Beam splitting in chiral nematic liquid crystals

2018 ◽  
Vol 10 (4) ◽  
pp. 109
Author(s):  
Filip Sala
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Nematic Liquid Crystal ◽  
Soft Matter ◽  
Nematic Liquid Crystals ◽  
Beam Propagation Method ◽  
Beam Propagation ◽  
Optical Solitons ◽  
Molecular Reorientation ◽  
Chiral Nematic

By lunching the beam into the chiral nematic liquid crystals it is possible to achieve a non-diffractive beam similar to a soliton. This effect is caused by the molecular reorientation i.e. nonlinear response of the material forming the areas of higher refractive index. Diffraction is suppressed by the focusing effect. For appropriate launching conditions it is also possible to achieve a beam which splits into two or more separate beams. Such phenomenon is discussed in this article and analyzed theoretical. To model this effect Fully Vectorial Beam Propagation Method coupled with the Frank-Oseen elastic theory is used. Simulations are performed for various input beam powers, widths, polarization angles and launching positions. Full Text: PDF ReferencesG. Assanto and M. A. Karpierz, "Nematicons: self-localised beams in nematic liquid crystals", Liq. Cryst. 36, 1161–1172 (2009) CrossRef G. Assanto, Nematicons: Spatial Optical Solitons in Nematic Liquid Crystals, John Wiley & Sons Inc. Hoboken, New Jersey (2013) DirectLink A. Piccardi, A. Alberucci, U. Bortolozzo, S. Residori, and G. Assanto, "Soliton gating and switching in liquid crystal light valve", Appl. Phys. Lett. 96, 071104 (2010). CrossRef D. Melo, I. Fernandes, F. Moraes, S. Fumeron, and E. Pereira, "Thermal diode made by nematic liquid crystal", Phys. Lett. A 380, 3121 – 3127 (2016). CrossRef U. Laudyn, M. Kwaśny, F. A. Sala, M. A. Karpierz, N. F. Smyth, G. Assanto, "Curved optical solitons subject to transverse acceleration in reorientational soft matter", Sci. Rep. 7, 12385 (2017) CrossRef M. Kwaśny, U. A. Laudyn, F. A. Sala, A. Alberucci, M. A. Karpierz, G. Assanto, "Self-guided beams in low-birefringence nematic liquid crystals", Phys. Rev. A 86, 013824 (2012) CrossRef F. A. Sala, M. M. Sala-Tefelska, "Optical steering of mutual capacitance in a nematic liquid crystal cell", J. Opt. Soc. Am. B. 35, 133-139 (2018) CrossRef U. A. Laudyn, A. Piccardi, M. Kwasny, M. A. Karpierz, G. Assanto, "Thermo-optic soliton routing in nematic liquid crystals", Opt. Lett. 43, 2296-2299 (2018) CrossRef F. A. Sala, M. M. Sala-Tefelska, M. J. Bujok, J. "Influence of temperature diffusion on molecular reorientation in nematic liquid crystals", Nonlinear Opt. Phys. Mater. 27, 1850011 (2018) CrossRef I-C Khoo Liquid crystals John Wiley & Sons, Inc (2007) DirectLink P. G. de Gennes, J. Prost, The Physics of Liquid Crystals, Clarendon Press (1995) DirectLink U. A. Laudyn, P. S. Jung, M. A. Karpierz, G. Assanto, "Quasi two-dimensional astigmatic solitons in soft chiral metastructures", Sci. Rep. 6, 22923 (2016) CrossRef J. Beeckman, A. Madani, P. J. M. Vanbrabant, P. Henneaux, S-P. Gorza, M. Haelterman, "Switching and intrinsic position bistability of soliton beams in chiral nematic liquid crystals", Phys. Rev. A 83, 033832 (2011) CrossRef A. Madani, J. Beeckman, K. Neyts, "An experimental observation of a spatial optical soliton beam and self splitting of beam into two soliton beams in chiral nematic liquid crystal", Opt. Commun. 298–299, 222-226, (2013) CrossRef G. D. Ziogos, E. E. Kriezis, "Modeling light propagation in liquid crystal devices with a 3-D full-vector finite-element beam propagation method", Opt. Quant. Electron 40, 10 (2008) CrossRef F. A. Sala, M. A. Karpierz, "Chiral and nonchiral nematic liquid-crystal reorientation induced by inhomogeneous electric fields", J. Opt. Soc. Am. B 29, 1465-1472 (2012) CrossRef F. A. Sala, M. A. Karpierz, "Modeling of molecular reorientation and beam propagation in chiral and non-chiral nematic liquid crystals", Opt. Express 20, 13923-13938 (2012) CrossRef F. A. Sala, "Design of false color palettes for grayscale reproduction", Displays, 46, 9-15 (2017) CrossRef

scholarly journals Light-Controlled Lyotropic Liquid Crystallinity of Polyaspartates

2021 ◽  
Author(s):  
Max Hirschmann ◽  
Christina M. Thiele
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Morphological Changes ◽  
Thermal Relaxation ◽  
Lyotropic Liquid Crystals ◽  
Solution Viscosity ◽  
Layer By Layer ◽  
Nano Technology ◽  
Biological Responses ◽  
Photo Alignment

<p><b>In nature, proteins like rhodopsin act as transducer for photo-chemical reactions causing biological responses (e.g. enabling vision)</b><b>. The underlying concept – a photo-induced conformational change of the protein as amplifier of the photo-responsive moiety – can also be adopted by synthetical polymers or foldamers</b><b> </b><b>that have the propensity to form ordered secondary structures (e.g. polypeptides)</b><b>. An alternative approach to amplify photo-chemical responses is their incorporation into liquid crystals</b><b>. With only a few exceptions</b><b>, photo-insensitive liquid crystals are doped with dyes</b><b> </b><b>that favour disorder upon irradiation</b><b>. In theory, photo-responsive polypeptides</b><b>, capable of forming lyotropic liquid crystals</b><b>, could exploit both amplification approaches but, in practice, their photo-responsivity is hampered by the reduced mobility of polypeptides in concentrated solutions</b><b>. Here we show that the E/Z photo-isomerisation of an azobenzene containing polyaspartate initiates a helix-coil backbone transition, which reversibly alters the polypeptide solution from anisotropic to isotropic. In contrast to other photo-responsible polymers</b><b>14</b><b>, in which thermal relaxation to the more stable photo-isomer is quite fast, both photo-isomers are thermally stable and interconvertible by visible light in a single solvent. Local irradiation and magnetic fields lead to spatial resolution and unidirectional architectures of the liquid crystal, respectively. Our results demonstrate that photo-isomerisation on a molecular level is amplified in three stages via intra- and intermolecular interactions to yield a unidirectional, chiral liquid crystal. We believe, the morphological changes of the liquid crystal induced by light will facilitate a multitude of applications, like photo-alignment</b><b> </b><b>or the photo-control of solution viscosity</b><b> </b><b>and anisotropic </b><br></p> <p><b>diffusion</b><b>. When incorporated into layer-by-layer architectures the polymer could find application in biomedicine</b><b> </b><b>and the spatial and temporal resolution could be exploited in nano-technology</b><b>. </b></p>

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