scholarly journals Virtual and real experiment in the study of the twist effect in a liquid crystal

2021 ◽  
Vol IX(246) (97) ◽  
pp. 37-42
Author(s):  
S. P. Velychko ◽  
V. V. Nelipovich
Keyword(s):  
Liquid Crystal ◽  
Real Experiment ◽  
Twist Effect

Dynamics of twist effect in a dual-frequency nematic liquid crystal

2009 ◽  
Vol 54 (4) ◽  
pp. 555-560 ◽  
Author(s):  
E. A. Konshina ◽  
M. A. Fedorov ◽  
A. E. Rybnikova ◽  
L. P. Amosova ◽  
N. L. Ivanova ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Dual Frequency ◽  
Twist Effect

scholarly journals STUDY OF MAGNETICALLY INDUCED TWIST EFFECT IN PLANAR NEMATIC LIQUID CRYSTAL BY PHASE RETARDATION METHOD

1999 ◽  
Vol 48 (10) ◽  
pp. 1898
Author(s):  
LIN ZI-YANG ◽  
XIANG YING ◽  
ZHANG JIE-LI ◽  
MA SHI-YONG ◽  
XU ZE-DA
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Phase Retardation ◽  
Twist Effect

Numerical Simulation Of A Voltage-Dependent Surface-Induced Molecular Reorientation In A Confined Nematic Liquid Crystal

2001 ◽  
Vol 709 ◽  
Author(s):  
J.J. Castro ◽  
A. Calles ◽  
R. M. Valladares
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Relaxation Method ◽  
Dielectric Anisotropy ◽  
Molecular Reorientation ◽  
Induced Dipole ◽  
Voltage Dependent ◽  
Lattice Approximation ◽  
Orientational Ordering ◽  
Twist Effect

ABSTRACTWe present a computer simulation of the voltage-dependent orientational ordering of a nematic liquid crystal within the lattice approximation, confined between two substrates with different anchoring for each surface. The system is studied by analyzing the response of the molecular reorientation near the surfaces as a function of the applied voltage. The model considers a molecular interaction responsible for the nematic phase that includes a superposition of the anisotropic induced-dipole-induced-dipole and isotropic Maier-Saupe interactions, whereas for the nematic-surface intermolecular interaction we assume the Rapini-Papoular form. The response to the external electric field is studied by calculating the dielectric constant tensor, based on a model through the molecular polarizability. We particularly discussed the case for negative dielectric anisotropy that could have relevance for the voltage controlled twist effect. The simulation is carried through a numerical relaxation method for the total energy of the system.

Freeze-fracture TEM of the helical smectic A* phase

1992 ◽  
Vol 50 (1) ◽  
pp. 278-279
Author(s):  
K.J. Ihn ◽  
R. Pindak ◽  
J. A. N. Zasadzinski
Keyword(s):  
Liquid Crystal ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Freeze Fracture ◽  
Smectic Phase ◽  
Layer Spacing ◽  
Screw Dislocations ◽  
Smectic A ◽  
Smectic Phases ◽  
Discrete Amount

A new liquid crystal (called the smectic-A* phase) that combines cholesteric twist and smectic layering was a surprise as smectic phases preclude twist distortions. However, the twist grain boundary (TGB) model of Renn and Lubensky predicted a defect-mediated smectic phase that incorporates cholesteric twist by a lattice of screw dislocations. The TGB model for the liquid crystal analog of the Abrikosov phase of superconductors consists of regularly spaced grain boundaries of screw dislocations, parallel to each other within the grain boundary, but rotated by a fixed angle with respect to adjacent grain boundaries. The dislocations divide the layers into blocks which rotate by a discrete amount, Δθ, given by the ratio of the layer spacing, d, to the distance between grain boundaries, lb; Δθ ≈ d/lb (Fig. 1).

Attractive mode force microscopy of chiral liquid crystal surfaces

1992 ◽  
Vol 50 (1) ◽  
pp. 268-269
Author(s):  
B.D. Terris ◽  
R. J. Twieg ◽  
C. Nguyen ◽  
G. Sigaud ◽  
H. T. Nguyen
Keyword(s):  
Liquid Crystal ◽  
Crystal Surfaces ◽  
Free Surfaces ◽  
Control Range ◽  
Force Microscopy ◽  
Liquid Crystal Films ◽  
Chiral Liquid Crystal ◽  
Crystal Films ◽  
Electrostatic Charging ◽  
And Shifts

We have used a force microscope in the attractive, or noncontact, mode to image a variety of surfaces. In this mode, the microscope tip is oscillated near its resonant frequency and shifts in this frequency due to changes in the surface-tip force gradient are detected. We have used this technique in a variety of applications to polymers, including electrostatic charging, phase separation of ionomer surfaces, and crazing of glassy films.Most recently, we have applied the force microscope to imaging the free surfaces of chiral liquid crystal films. The compounds used (Table 1) have been chosen for their polymorphic variety of fluid mesophases, all of which exist within the temperature control range of our force microscope.

Development of liquid crystal light valves using Bi12SiO20 as the photoconductor. Part 2: Device performance

1986 ◽  
Vol 133 (1) ◽  
pp. 65
Author(s):  
W.L. Baillie ◽  
P.M. Openshaw ◽  
A.D. Hart ◽  
S.S. Makh
Keyword(s):  
Liquid Crystal ◽  
Device Performance
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