Novel Memory Effect Found in Nematic Liquid Crystal/Clay Mineral Composites

1996 ◽  
Vol 425 ◽  
Author(s):  
M. Kawasumi ◽  
N. Hasegawa ◽  
A. Usuki ◽  
A. Okada ◽  
T. Kurauchi
Keyword(s):  
Liquid Crystal ◽  
Light Scattering ◽  
Electric Field ◽  
Memory Effect ◽  
Clay Mineral ◽  
Nematic Liquid Crystal ◽  
Liquid Crystalline ◽  
Optical Effect ◽  
Scattering States ◽  
Memory States

AbstractNovel liquid crystalline composites composed of a nematic two-frequency-addressing liquid crystal and organized clay mineral have been prepared. The particles of the clay mineral were dispersed homogeneously in the liquid crystal. The composite cells displayed a reversible and multistable electro-optical effect between transparent and turbid light scattering states by changing the frequency of the electric field. The light transmittances of both transparent and light scattering memory states did not change after 15 hrs without the electric field applied.

scholarly journals A fast linear electro-optical effect in a non-chiral bent-core liquid crystal

2017 ◽  
Vol 5 (47) ◽  
pp. 12585-12590 ◽  
Author(s):  
Yu. P. Panarin ◽  
S. P. Sreenilayam ◽  
J. K. Vij ◽  
A. Lehmann ◽  
C. Tschierske
Keyword(s):  
Liquid Crystal ◽  
Electric Field ◽  
Liquid Crystalline ◽  
Optical Axis ◽  
Smectic Phase ◽  
Optical Effect ◽  
Electro Optical Effect ◽  
Helical State

We report on the observation of an electro-optical effect for a linear rotation of the optical axis as a function of the electric field in a tilted liquid crystalline smectic phase of an achiral bent-core compound, attributed to a spontaneous helical state in its SmCSPF phase.

scholarly journals Reflective Bistable Chiral Splay Nematic Liquid Crystal for Low-Power Heat Sensor

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 5937
Author(s):  
Chao Ping Chen ◽  
Chul Gyu Jhun
Keyword(s):  
Liquid Crystal ◽  
Low Power ◽  
Memory Effect ◽  
Nematic Liquid Crystal ◽  
Matrix Method ◽  
Contrast Ratio ◽  
Jones Matrix ◽  
Long Time ◽  
Heat Sensor ◽  
Memory States

The memory effect of the bistable liquid crystal mode is able to maintain the display information for a long time. The splay state and π twist states are used as the memory states of the bistable chiral splay nematic (BCSN) mode. The transition time from the π twist state to the splay state is sensitive to the temperature. In this paper, for the heat sensor application, the reflective structure of the BCSN mode has been studied by the Jones matrix method. In experiments, the measured contrast ratio can be over 200 with a minimal reflective structure including a single polarizer and a reflector.

LIQUID CRYSTLASLIGHT SCATTERING BY FLUCTUATIONS INDUCED BY AN APPLIED ELECTRIC FIELD IN A NEMATIC LIQUID CRYSTAL (APAPA)

1972 ◽  
Vol 33 (C1) ◽  
pp. C1-63-C1-67 ◽  
Author(s):  
M. BERTOLOTTI ◽  
B. DAINO ◽  
P. Di PORTO ◽  
F. SCUDIERI ◽  
D. SETTE
Keyword(s):  
Liquid Crystal ◽  
Electric Field ◽  
Nematic Liquid Crystal ◽  
Applied Electric Field

DYNAMIC LIGHT SCATTERING IN LC-440 NEMATIC LIQUID CRYSTAL

2014 ◽  
Vol 73 (11) ◽  
pp. 977-983
Author(s):  
A. P. Fedoryako ◽  
A. I. Kocherzhin ◽  
M. P. Kukhtin ◽  
E. I. Chernyakov
Keyword(s):  
Liquid Crystal ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Nematic Liquid Crystal

scholarly journals Modeling Static Electric Field Effect on Nematic Liquid Crystal Director Orientation in Side-Electrode Cell

2018 ◽  
Vol 173 ◽  
pp. 03002 ◽  
Author(s):  
Alexander Ayriyan ◽  
Edik Ayryan ◽  
Alexandre Egorov ◽  
Maria Dencheva-Zarkova ◽  
Georgi Hadjichristov ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Electric Field ◽  
Nematic Liquid Crystal ◽  
Finite Difference Methods ◽  
Electric Field Effect ◽  
Dimensional Model ◽  
Static Electric Field ◽  
Electrode Cell ◽  
Field Influence ◽  
Director Orientation

A two-dimensional model of Fredericks effect was used for the investigation of the static electric field influence on nematic liquid crystal director orientation in the side-electrode cell. The solutions of the equations describing the model were obtained by finite-difference methods. Fredericks transition threshold for the central part of the cell, as well as dependencies of the distribution of the director orientation patterns on the electric field and location, were obtained. The numerical results are found to agree qualitatively with the experiment. Further investigations are needed to elucidate completely the Fredericks effect.

scholarly journals Mechanisms of Chiral Transfer in Optically Active Dopant – Nematic Liquid Crystal Systems

2020 ◽  
Vol 20 (4) ◽  
pp. 6-26
Author(s):  
V. A. Burmistrov ◽  
V. V. Aleksandriiskii ◽  
I. V. Novikov ◽  
O. I. Koifman
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Self Assembly ◽  
Liquid Crystalline ◽  
High Efficiency ◽  
Stationary Phases ◽  
Theoretical Description ◽  
Optically Active ◽  
Axial Coordination ◽  
Chiral Dopants

Induction of helical mesophases by incorporating chiral dopants into the nematics matrix is the promising modern trends in the chemistry of liquid crystals. This process is associated with a unique phenomenon - an amplification of chirality in liquid-crystalline phases, which ensures the detection of enantiomers by their chiral induction, much more sensitive than other methods. The relevance of this approach is due to the need to create perspective electro-optical devices operating with ultra-low control voltages based on twist effects, chromatographic stationary phases with high chiral selectivity, flexible magnets, photo-sensitive nanostructures, and other smart LC materials. The successful solution of these problems is impossible without experimental research and theoretical comprehension of the mechanisms of third level chiral transfer optically active dopant – nematic liquid crystal. In the last decade, a large number of works have appeared on the solution of these problems. This review is devoted to a generalization of the experimental results and a theoretical description of the transfer of molecular chirality to orientationally ordered systems with the participation of both chiral molecular substituents with an asymmetric carbon atom and planar or quasi-planar fragments chirally distorted relative to each other. The stereochemical aspects of induction associated with the structural correspondences of the dopant and nematic liquid crystal, as well as the main classes of optically active additives, are discussed. Application of metal complexes, both Werner and macroheterocyclic, are presented. Special attention is paid to the results of the mechanisms study of chiral transfer due to various intermolecular interactions: hydrogen bonding, axial coordination, and the formation of inclusion compounds. The high efficiency of induction of spiral mesophases has been demonstrated with a combination of different self-assembly mechanisms in liquid crystal - chiral additive systems.

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