Nano-Sized Fine Droplets of Liquid Crystals for Optical Application

1996 ◽  
Vol 457 ◽  
Author(s):  
Shiro Matsumoto ◽  
Marthe Houlbert ◽  
Takayoshi Hayashi ◽  
Ken-ichi Kubodera
Keyword(s):  
Liquid Crystal ◽  
Phase Separation ◽  
Liquid Crystals ◽  
Electric Field ◽  
Applied Voltage ◽  
Applied Electric Field ◽  
Uv Curing ◽  
Infrared Region ◽  
High Transparency ◽  
Power Change

ABSTRACTNano-sized fine droplets of liquid crystal (LC) were obtained by phase separation of nematic LC in UV curing polymer. The polymer composite had a high transparency in the infrared region. The fine droplets responded to an electric field causing a change in birefringence. Output power change was brought about by the generated retardation between two polarizations, parallel and perpendicular to the applied electric field. This differs from the composite containing much larger droplets, where output depends on the degree of scattering. The birefringence changed by 0.001 at the applied voltage of 7.5 V/μm.

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.

Microsecond Time-Resolved Infrared Study of the Electric-Field-Induced Reorientation of Nematic Liquid Crystals. Part II: Dependence of the Motion of Liquid Crystals on the Applied Electric Field

1993 ◽  
Vol 47 (12) ◽  
pp. 2108-2113 ◽  
Author(s):  
Taeko I. Urano ◽  
Hiro-O Hamaguchi
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Electric Field ◽  
Applied Electric Field ◽  
Slow Component ◽  
Fast Component ◽  
Rigid Core ◽  
Time Resolved ◽  
Flexible Part ◽  
Reorientation Motion

The electric-field dependence of the reorientation motion of a nematic liquid crystal, 5CB (4- n-pentyl-4'-cyanobiphenyl), has been studied by microsecond time-resolved infrared spectroscopy. A rectangular pulsed electric field with a short pulse duration (2 ms) and a low repetition rate (5 Hz) was used to examine the liquid crystal (LC) response in a silicon cell. The motion of the rigid core part (the cyanobiphenyl group) of 5CB was monitored by the CN stretch band and that of the flexible part (the pentyl group) by the pentyl CH stretch band. The response of the LC to the pulsed electric field consists of two components, the slow component and the fast component. The slow component is common to the rigid core and the flexible parts of SCB. The voltage dependence of the slow component exhibits a clear threshold, indicating that this component corresponds to a cooperative motion of the 5CB molecules. The fast component is specific to the flexible part and shows exponential rise and decay behavior patterns. This observation suggests that the fast component corresponds to some noncooperative motions which are characteristic of the pentyl group. It is most likely that the internal rotation around the C(biphenyl)-C(pentyl) bond is responsible for the fast component. It is suggested that the LC molecules near the cell interface play a key role in the primary stage of the reorientation motion under an applied electric field.

scholarly journals Holographic Characteristics of Photopolymers Containing Different Mixtures of Nematic Liquid Crystals

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 325 ◽  
Author(s):  
Sandra Fenoll ◽  
Francisco Brocal ◽  
José David Segura ◽  
Manuel Ortuño ◽  
Augusto Beléndez ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Light Intensity ◽  
Electric Field ◽  
Diffraction Efficiency ◽  
Applied Voltage ◽  
Nematic Liquid Crystals ◽  
Variable Electric Field ◽  
Polymer Dispersed Liquid Crystal ◽  
Polymer Dispersed

A holographic polymer dispersed liquid crystal (HPDLC) is used to record holographic diffraction gratings. Several mixtures of nematic liquid crystals (LC) are used as components of the HPDLC to evaluate their influence in static and dynamic basic properties. The diffraction efficiency obtained in the reconstruction of the holograms is evaluated to compare the influence of the different LC. Additionally, the samples are exposed to a variable electric field and the diffracted light intensity as a function of the applied voltage is measured to evaluate the influence of the LC. The results obtained show significant differences depending on the LC incorporated to the photopolymer.

scholarly journals Annihilation dynamics of topological defects induced by microparticles in nematic liquid crystals

Soft Matter ◽  
2019 ◽  
Vol 15 (43) ◽  
pp. 8749-8757 ◽  
Author(s):  
Yuan Shen ◽  
Ingo Dierking
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Electric Field ◽  
Applied Electric Field ◽  
Topological Defects ◽  
Field Conditions ◽  
Viscous Drag ◽  
Complex Interplay ◽  
Drag Forces ◽  
Micro Particles

The annihilation dynamics of liquid crystal topological defects with micro-particles is governed by a complex interplay between elastic attraction, backflow, viscous drag forces, confinement and applied electric field conditions.

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

Investigation on dynamic holographic display in liquid crystal film doped with carbon dots

2020 ◽  
Vol 10 (6) ◽  
pp. 780-787
Author(s):  
Hongyue Gao ◽  
Suna Li ◽  
Jicheng Liu ◽  
Wen Zhou ◽  
Fan Xu ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Electric Field ◽  
Real Time ◽  
Diffraction Efficiency ◽  
Carbon Dots ◽  
Applied Electric Field ◽  
Light Polarization ◽  
Forming Process ◽  
Time Dynamic ◽  
Holographic Display

In this paper, we studied the holographic properties of liquid crystal (LC) thin film doped with carbon dots (CDs) which can be used as real-time holographic display screen. The maximum value of diffraction efficiency can reach up to 30% by using a low applied electric field 0.2 V/μm. Holograms in the LC film can be dynamically formed and self-erased. The hologram build-up time and the hologram self-erasure time in the material is fast enough to realize video refresh rate. In addition, the forming process of hologram was studied. The holographic diffraction efficiency was measured depending on the intensity of recording light, applied electric field, the intensity of readout light, and readout light polarization direction. Triple enhancement of the diffraction efficiency value by the modulation of voltage under the condition of low recording energy is presented. Therefore, we develop an easy way to obtain real-time dynamic holographic red, green and blue displays with high diffraction efficiency, which allow the LC film doped with CDs to be used as a holographic 3D display screen.

scholarly journals Evaluation of 4-alkoxy-4′-nitrobiphenyl liquid crystals for use in next generation scattering LCDs

RSC Advances ◽  
2017 ◽  
Vol 7 (64) ◽  
pp. 40480-40485 ◽  
Author(s):  
Richard J. Mandle ◽  
Stephen J. Cowling ◽  
John W. Goodby
Keyword(s):  
Liquid Crystals ◽  
Electric Field ◽  
Applied Electric Field ◽  
Field Studies ◽  
Next Generation ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

A combination of microscopy, X-ray scattering, calorimetry and applied electric field studies demonstrates the 4-alkoxy-4′-nitrobiphenyls are potentially of use for next generation, backlight free scattering mode LCD devices.

New liquid crystal formation induced by nanoscale phase separation composed of bent-core liquid crystal and rod-like cholesteric liquid crystal mixtures

Soft Matter ◽  
2021 ◽  
Author(s):  
Yoichi Takanishi
Keyword(s):  
Liquid Crystal ◽  
Phase Separation ◽  
Liquid Crystals ◽  
Small Angle ◽  
Cholesteric Liquid Crystal ◽  
Crystal Formation ◽  
Nano Structure ◽  
X Ray ◽  
Nanoscale Phase Separation ◽  
X Ray Scattering

Herein, the local nano-structure in mixtures of cholesteric liquid crystals and a bent-core molecule was analyzed via the small-angle X-ray scattering.

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