Polar-horizontal versus polar-vertical reverse-tilt-domain walls: Influence of a pretilt angle below the nematic-isotropic phase transition

2008 ◽  
Vol 78 (2) ◽  
Author(s):  
Ji-Hoon Lee ◽  
Timothy J. Atherton ◽  
Daeseung Kang ◽  
Rolfe G. Petschek ◽  
Charles Rosenblatt
Keyword(s):  
Phase Transition ◽  
Domain Walls ◽  
Isotropic Phase ◽  
Pretilt Angle

Nonlinear Optical Absorption and Related Phenomena in Liquid Crystals

2001 ◽  
Vol 709 ◽  
Author(s):  
N.V. Tabiryan ◽  
U.A. Hrozhyk ◽  
H.L. Margaryan ◽  
M.J. Mora ◽  
S.R. Nersisyan ◽  
...  
Keyword(s):  
Phase Transition ◽  
Light Scattering ◽  
Optical Absorption ◽  
Nonlinear Absorption ◽  
Nonlinear Optical ◽  
Isotropic Phase ◽  
Nonlinear Optical Absorption ◽  
Critical Opalescence ◽  
Application Potential ◽  
Large Application

SUMMARYThus, in the present paper, we reported about several processes of nonlinear absorption and transmission in dye-doped NLC: nonlinear absorption due to light induced reorientation of NLC doped by highly dichroic dyes; nonlinear transmission due to nonlinear birefringence, and self-extinguishing of the beam due to”critical opalescence,” critically enhanced light scattering at the pre-transition region of nematic-isotropic phase transition. All these processes have large application potential for laser beam control and characterization techniques.

Thermal phase transition behaviours of the blue phase of bent-core nematogen and chiral dopant mixtures under different boundary conditions

Soft Matter ◽  
2014 ◽  
Vol 10 (41) ◽  
pp. 8224-8228 ◽  
Author(s):  
Min-Jun Gim ◽  
Gohyun Han ◽  
Suk-Won Choi ◽  
Dong Ki Yoon
Keyword(s):  
Phase Transition ◽  
Boundary Conditions ◽  
Liquid Crystalline ◽  
Isotropic Phase ◽  
Different Boundary Conditions ◽  
Various Boundary Conditions ◽  
Thermal Phase Transition ◽  
Thermal Phase ◽  
Blue Phase ◽  
Chiral Dopants

We have investigated dramatic changes in the thermal phase transition of a liquid-crystalline (LC) blue phase (BP) consisting of bent-core nematogen and chiral dopants under various boundary conditions during cooling from the isotropic phase.

scholarly journals Dissipative structures induced by photoisomerization in a dye-doped nematic liquid crystal layer

2018 ◽  
Vol 376 (2135) ◽  
pp. 20170382 ◽  
Author(s):  
I. Andrade-Silva ◽  
U. Bortolozzo ◽  
C. Castillo-Pinto ◽  
M. G. Clerc ◽  
G. González-Cortés ◽  
...  
Keyword(s):  
Phase Transition ◽  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Dissipative Structures ◽  
Input Power ◽  
Isotropic Phase ◽  
Crystal Layer ◽  
Liquid Crystal Layer ◽  
Nematic Liquid Crystal Layer ◽  
Interface Propagation

Order–disorder phase transitions driven by temperature or light in soft matter materials exhibit complex dissipative structures. Here, we investigate the spatio-temporal phenomena induced by light in a dye-doped nematic liquid crystal layer. Experimentally, for planar anchoring of the nematic layer and high enough input power, photoisomerization processes induce a nematic–isotropic phase transition mediated by interface propagation between the two phases. In the case of a twisted nematic layer and for intermediate input power, the light induces a spatially modulated phase, which exhibits stripe patterns. The pattern originates as an instability mediated by interface propagation between the modulated and the homogeneous nematic states. Theoretically, the phase transition, emergence of stripe patterns and front dynamics are described on the basis of a proposed model for the dopant concentration coupled with the nematic order parameter. Numerical simulations show quite a fair agreement with the experimental observations. This article is part of the theme issue ‘Dissipative structures in matter out of equilibrium: from chemistry, photonics and biology (part 2)’.

scholarly journals Perylene-like Dyes in Liquid Crystalline Media

1996 ◽  
Vol 51 (7) ◽  
pp. 843-850 ◽  
Author(s):  
Ewa Mykowska ◽  
Danuta Bauman
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Order Parameter ◽  
Liquid Crystalline ◽  
Fluorescent Dyes ◽  
Liquid Crystal Display ◽  
Isotropic Phase ◽  
Display Devices ◽  
Electrooptical Properties ◽  
Derivatives Of

Abstract The spectral and electrooptical properties of some dichroic fluorescent dyes (derivatives of 3.4,9,10-perylenetetracorboxylic acid and of 3,4,9-perylenetricarboxylic acid) in isotropic solvents and nematic liquid crystals have been studied. The order parameter of the dyes in the anisotropic matrices has been determined by means of optical spectroscopy methods. Moreover, the influence of the dye addition on the nematic-isotropic phase transition temperature of the pure host has been investigated. It was found that some of the dyes studied can be utilized in guest-host liquid crystal display devices.

scholarly journals Kinetics of Nematic to Isotropic Phase Transition in Liquid Crystal Doped with Magnetic Nanoparticles

2017 ◽  
Vol 131 (4) ◽  
pp. 949-951 ◽  
Author(s):  
K. Csach ◽  
A. Juríková ◽  
J. Miškuf ◽  
N. Tomašovičová ◽  
V. Gdovinová ◽  
...  
Keyword(s):  
Phase Transition ◽  
Liquid Crystal ◽  
Magnetic Nanoparticles ◽  
Isotropic Phase ◽  
Kinetics Of
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