Light Scattering through the Isotropic-Cholesteric Phase Transition of a Cholesteric Liquid Crystal

1975 ◽  
Vol 34 (20) ◽  
pp. 1259-1262 ◽  
Author(s):  
T. Harada ◽  
P. P. Crooker
Keyword(s):  
Phase Transition ◽  
Liquid Crystal ◽  
Light Scattering ◽  
Cholesteric Liquid Crystal ◽  
Cholesteric Phase

scholarly journals Control of the Induced Handedness of Helical Nanofilaments Employing Cholesteric Liquid Crystal Fields

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 6055
Author(s):  
Ju-Yong Kim ◽  
Jae-Jin Lee ◽  
Jun-Sung Park ◽  
Yong-Jun Choi ◽  
Suk-Won Choi
Keyword(s):  
Liquid Crystal ◽  
Crystal Field ◽  
Driving Force ◽  
Cholesteric Liquid Crystal ◽  
Powerful Method ◽  
Cholesteric Phase ◽  
Crystal Fields

In this paper, a simple and powerful method to control the induced handedness of helical nanofilaments (HNFs) is presented. The nanofilaments are formed by achiral bent-core liquid crystal molecules employing a cholesteric liquid crystal field obtained by doping a rod-like nematogen with a chiral dopant. Homochiral helical nanofilaments are formed in the nanophase-separated helical nanofilament/cholesteric phase from a mixture with a cholesteric phase. This cholesteric phase forms at a temperature higher than the temperature at which the helical nanofilament in a bent-core molecule appears. Under such conditions, the cholesteric liquid crystal field acts as a driving force in the nucleation of HNFs, realizing a perfectly homochiral domain consisting of identical helical nanofilament handedness.

Thermally induced light-scattering effects as responsible for the degradation of cholesteric liquid crystal lasers

2015 ◽  
Vol 40 (7) ◽  
pp. 1262 ◽  
Author(s):  
J. Etxebarria ◽  
J. Ortega ◽  
C. L. Folcia ◽  
G. Sanz-Enguita ◽  
I. Aramburu
Keyword(s):  
Liquid Crystal ◽  
Light Scattering ◽  
Cholesteric Liquid Crystal ◽  
Thermally Induced ◽  
Scattering Effects ◽  
Liquid Crystal Lasers

A 5-Mpixel overhead projection display utilizing a nematic-cholesteric phase-transition liquid crystal

1993 ◽  
Vol 1 (1) ◽  
pp. 43 ◽  
Author(s):  
Yoshikazu Yabe ◽  
Hisatake Yamada ◽  
Toshihiro Hoshi ◽  
Toshiaki Yoshihara ◽  
Akihiro Mochizuki ◽  
...  
Keyword(s):  
Phase Transition ◽  
Liquid Crystal ◽  
Cholesteric Phase ◽  
Projection Display ◽  
Overhead Projection

scholarly journals Periodic assembly of nanoparticle arrays in disclinations of cholesteric liquid crystals

2017 ◽  
Vol 114 (9) ◽  
pp. 2137-2142 ◽  
Author(s):  
Yunfeng Li ◽  
Elisabeth Prince ◽  
Sangho Cho ◽  
Alinaghi Salari ◽  
Youssef Mosaddeghian Golestani ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Self Assembly ◽  
Soft Matter ◽  
Cholesteric Liquid Crystal ◽  
Topological Defects ◽  
Spatial Inhomogeneity ◽  
Cholesteric Phase ◽  
Anisotropic Surface ◽  
Linear Defects

An important goal of the modern soft matter science is to discover new self-assembly modalities to precisely control the placement of small particles in space. Spatial inhomogeneity of liquid crystals offers the capability to organize colloids in certain regions such as the cores of the topological defects. Here we report two self-assembly modes of nanoparticles in linear defects-disclinations in a lyotropic colloidal cholesteric liquid crystal: a continuous helicoidal thread and a periodic array of discrete beads. The beads form one-dimensional arrays with a periodicity that matches half a pitch of the cholesteric phase. The periodic assembly is governed by the anisotropic surface tension and elasticity at the interface of beads with the liquid crystal. This mode of self-assembly of nanoparticles in disclinations expands our ability to use topological defects in liquid crystals as templates for the organization of nanocolloids.

Cholesteric liquid crystal glass platinum acetylides

2014 ◽  
Vol 1698 ◽  
Author(s):  
Thomas M. Cooper ◽  
Aaron R. Burke ◽  
Douglas M. Krein ◽  
Ronald F. Ziolo ◽  
Eduardo Arias ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Optical Materials ◽  
Liquid Crystalline ◽  
Room Temperature ◽  
Cholesteric Liquid Crystal ◽  
Isotropic Phase ◽  
Crystal Glass ◽  
Cholesteric Phase ◽  
Long Time ◽  
Cholesteric Liquid Crystalline

ABSTRACTTo prepare cholesteric liquid crystalline nonlinear optical materials with ability to be vitrified on cooling and form long time stability cholesteric glasses at room temperature, a series of platinum acetylide complexes modified with cholesterol has been synthesized. The materials synthesized have the formula trans-Pt(PR3)(cholesterol (3 or 4)-ethynyl benzoate)(1-ethynyl-4-X-benzene), where R = Et, Bu or Oct and X = H, F, OCH3 and CN. A cholesteric liquid crystal phase was observed in the complexes R = Et, and X = F, OCH3 and CN but not in any of the other complexes. When X = CN, a cholesteric glass was observed at room temperature which remained stable up to 130 °C, then converted to a mixed crystalline/cholesteric phase and completely melted to an isotropic phase at 230 °C. When X = F or OCH3 the complexes were crystalline at room temperature with conversion to the cholesteric phase upon heating to 190 and 230 °C, respectively. In the series X = CN, OCH3 and F, the cholesteric pitch was determined to be 1.7, 3.4 and 9.0 µ, respectively.

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