Measurement of nematic liquid crystal splay elastic constants by disclination line motion in high pretilt, negative dielectric anisotropy pi-cells

2012 ◽  
Vol 112 (10) ◽  
pp. 103525 ◽  
Author(s):  
Harry G. Walton
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Elastic Constants ◽  
Dielectric Anisotropy ◽  
Disclination Line

scholarly journals Effect of Doping ofCd1−xZnxS/ZnS Core/Shell Quantum Dots in Negative Dielectric Anisotropy Nematic Liquid Crystal p-Methoxybenzylidene p-Decylaniline

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 605
Author(s):  
Ayushi Rastogi ◽  
Fanindra Pandey ◽  
Rajiv Manohar ◽  
Shri Singh
Keyword(s):  
Quantum Dots ◽  
Liquid Crystal ◽  
Dielectric Permittivity ◽  
Nematic Liquid Crystal ◽  
Phase Shifters ◽  
Ion Trapping ◽  
Dielectric Anisotropy ◽  
Core Shell ◽  
Optical Parameters ◽  
Dielectric Parameters

We report the effect of the doping of Cd1−xZnxS/ZnS core/shell quantum dots (CSQDs) in nematic liquid crystal p-methoxybenzylidenep-decylaniline (MBDA) at 0.05 wt/wt%, 0.1 wt/wt%, 0.15 wt/wt%, 0.2 wt/wt%, 0.25 wt/wt%, and 0.3 wt/wt% concentrations of CSQDs in MBDA. Dielectric parameters with and without bias with respect to frequency have been investigated. The change in electro-optical parameters with temperature has also been demonstrated. The increase in the mean dielectric permittivity was found due to the large dipole moment of CSQDs, which impose stronger interactions with the liquid crystal molecules. The dielectric anisotropy changes sign on doping CSQDs in MBDA liquid crystal. It was concluded that the CSQD doping noticeably increased the dielectric permittivity of nematic MBDA in the presence of an electric field. The doping of CSQDs in nematic MBDA liquid crystal reduced the ion screening effect effectively. This phenomenon is attributed to the competition between the generated ionic impurities during the assembling process and the ion trapping effect of the CSQDs. The rotational viscosity of nematic liquid crystal decreased with increasing concentration of the CSQDs, with a faster response time observed for the 0.05 wt/wt% concentration. The birefringence of the doped system increased with the inclusion of CSQDs in MBDA. These results find application in the field of display devices, phase shifters, LC – gratings, TIR waveguide, industries, and projectors.

Broadband Reflection Gels Prepared from Microcapsules Containing Chiral Nematic Liquid Crystal with Negative Dielectric Anisotropy

2012 ◽  
Vol 27 (5) ◽  
pp. 583-589
Author(s):  
李克轩 LI Ke-xuan ◽  
王慧慧 WANG Hui-hui ◽  
张立培 ZHANG Li-pei ◽  
何万里 HE Wan-li ◽  
曹晖 CAO Hui ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Dielectric Anisotropy ◽  
Chiral Nematic

Bestimmung von Elastizitätskoeffizienten einer nematischen Flüssigkeit durch elektrische Leitfähigkeitsmessungen / Elastic constants of a nematic liquid crystal determined by electric conductivity measurements

1973 ◽  
Vol 28 (10) ◽  
pp. 1660-1667 ◽  
Author(s):  
F. Schneider
Keyword(s):  
Magnetic Field ◽  
Liquid Crystal ◽  
Electric Conductivity ◽  
Nematic Liquid Crystal ◽  
Elastic Constants ◽  
Conductivity Measurements ◽  
Variable Strength ◽  
Tetrabutylammonium Picrate ◽  
Good Agreement

The influence of a magnetic field of variable strength and direction on the deformations and the electric conductivity of a nematic liquid crystal is treated theoretically. The results are in good agreement with measurements of the electric conductivity of MBBA, doped with tetrabutylammonium picrate. The bend and the splay elastic constants of MBBA are found to be k33 = 8.62 · 10-7 dyn and k11 = 6.38 · 10-7 dyn at 22.1 °C.

Sign inversion of dielectric anisotropy in nematic liquid crystal by dye doping

2010 ◽  
Vol 71 (9) ◽  
pp. 1311-1315 ◽  
Author(s):  
Rajiv Manohar ◽  
Kamal K. Pandey ◽  
Abhishek K. Srivastava ◽  
Abhishek K. Misra ◽  
Satya P. Yadav
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Dielectric Anisotropy ◽  
Sign Inversion ◽  
Dye Doping
Sign in / Sign up

Export Citation Format

Share Document