The behavior of the distortion angle for lyotropic nematic liquid crystals as a function of the magnetic field

1995 ◽  
Vol 200 (1) ◽  
pp. 56-60 ◽  
Author(s):  
A.J. Palangana ◽  
L.R. Evangelista ◽  
A.K. Zvezdin
Keyword(s):  
Magnetic Field ◽  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
The Magnetic Field ◽  
Distortion Angle

A DYNAMICAL METHOD FOR DETERMINING THE ELASTIC CONSTANTS AND RELAXATION PARAMETERS IN NEMATIC LIQUID CRYSTALS

2000 ◽  
Vol 14 (04) ◽  
pp. 139-146 ◽  
Author(s):  
EMIL PETRESCU ◽  
CORNELIA MOTOC ◽  
DOINA MANAILA
Keyword(s):  
Magnetic Field ◽  
Liquid Crystals ◽  
Elastic Constants ◽  
Light Transmission ◽  
Nematic Liquid Crystals ◽  
Relaxation Parameters ◽  
Nematic Director ◽  
Dynamical Method ◽  
The Magnetic Field ◽  
Good Agreement

The theoretical model proposed by Pieranski et al.3 to describe the phenomena occurring in nematic liquid crystals when the magnetic field is suddenly varied was extended by considering higher powers of the distortion angle for the nematic director. Equations giving the time evolution of the number of extinctions in the light transmission were obtained. These equations depend on some relaxation parameters (the time constants τA and τB intervening when the magnetic field was switched "on" or "off", respectively) and on the ratio of elastic constants. The equations were solved numerically and good agreement with the experimental data was obtained for the nematic MBBA.

Metastabile Deformationen in nematischen flüssigen Kristallen / Metastable Deformations in Nematic Liquid Crystals

1974 ◽  
Vol 29 (2) ◽  
pp. 310-318
Author(s):  
G. Heppke ◽  
F. Schneider
Keyword(s):  
Magnetic Field ◽  
Electrical Conductivity ◽  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
Experimental Studies ◽  
Conductivity Measurements ◽  
Elastic Deformations ◽  
The Magnetic Field ◽  
Good Agreement

The magnetic field induced elastic deformations of nematic liquid crystals are studied theoretically. In accordance with the theory of Dafermos, two types of elastic deformations are predicted which differ in energy. The properties of the metastable deformations are discussed in detail. Experimental studies have been performed on MBBA using electrical conductivity measurements. Metastable deformations are obtained after rotating the direction of the magnetic field by more than 90° with respect to the direction of the homeotropically aligned sample. The observed conductivity values are in good agreement with theory.

Dry-friction and critical state in lyotropic nematic liquid crystals in a magnetic field

1996 ◽  
Vol 222 (1-2) ◽  
pp. 113-118 ◽  
Author(s):  
E. Andreoli de Oliveira ◽  
G. Barbero ◽  
A.M. Figueiredo Neto ◽  
A.K. Zvezdin
Keyword(s):  
Magnetic Field ◽  
Liquid Crystals ◽  
Critical State ◽  
Dry Friction ◽  
Nematic Liquid Crystals

scholarly journals The Influence of Single-Walled Carbon Nanotubes on the Dynamic Properties of Nematic Liquid Crystals in Magnetic Field

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4031 ◽  
Author(s):  
Cirtoaje ◽  
Petrescu
Keyword(s):  
Magnetic Field ◽  
Liquid Crystals ◽  
Dynamic Properties ◽  
Relaxation Times ◽  
Continuum Theory ◽  
Elastic Continuum ◽  
Walled Carbon Nanotubes ◽  
The Impact ◽  
The Magnetic Field ◽  
Good Agreement

This article aims to study the impact of carbon nanotube dispersions in liquid crystals. A theoretical model for the system’s dynamics is presented, considering the elastic continuum theory and a planar alignment of liquid crystal molecules on the nanotube’s surface. Experimental calculation of the relaxation times in the magnetic field was made for two cases: when the field was switched on (τon), and when it was switched off (τoff). The results indicate an increase of the relaxation time by about 25% when the magnetic field was switched off, and a smaller increase (about 10%) when the field was switched on, where both were in good agreement with the theoretical values.

Sign in / Sign up

Export Citation Format

Share Document