Quantum dots dispersed hockey stick nematic liquid crystal: Studies on dielectric permittivity, elastic constants and electrical conductivity

2018 ◽  
Vol 266 ◽  
pp. 10-18 ◽  
Author(s):  
Jitendra Kumar ◽  
Veena Prasad ◽  
Monika Manjunath
Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 605
Author(s):  
Ayushi Rastogi ◽  
Fanindra Pandey ◽  
Rajiv Manohar ◽  
Shri Singh

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.


2017 ◽  
Vol 20 (04) ◽  
pp. 437-441 ◽  
Author(s):  
O.V. Kovalchuk ◽  
◽  
I.P. Studenyak ◽  
V.Yu. Izai ◽  
S.O. Rybak ◽  
...  

The influence of Cu7PS6 nanoparticles with the average size 117 nm on the dielectric properties of planar oriented nematic liquid crystal 6CB has been investigated within the frequency range 101…106 Hz and at the temperature 293 K. It has been shown that when changing the concentration of nanoparticles within the range 0 to 1 wt.%, the conductivity of the liquid crystal changes stronger than its dielectric permittivity. It has been shown that the electrical conductivity increases monotonously with increasing the concentration of nanoparticles. However, for this dependence a saturation effect is observed. The mechanism of this effect was proposed.


2021 ◽  
Vol 103 (5) ◽  
Author(s):  
Sourav Patranabish ◽  
Yiwei Wang ◽  
Aloka Sinha ◽  
Apala Majumdar

2011 ◽  
Vol 21 (34) ◽  
pp. 12710 ◽  
Author(s):  
Javad Mirzaei ◽  
Martin Urbanski ◽  
Kui Yu ◽  
Heinz-S. Kitzerow ◽  
Torsten Hegmann

1973 ◽  
Vol 28 (10) ◽  
pp. 1660-1667 ◽  
Author(s):  
F. Schneider

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.


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