scholarly journals Higly sensitive active medium of sensor NO2 , based on cholesteric nematic mixture with impurities of carbon nanotubes

2021 ◽  
Vol 22 (3) ◽  
pp. 426-431
Author(s):  
Z.M. Mykytyuk ◽  
M.V. Vistak ◽  
I.T. Kogut ◽  
V.V. Petryshak
Keyword(s):  
Carbon Nanotubes ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Active Medium ◽  
Spectral Sensitivity ◽  
Sensitivity Coefficient ◽  
Gas Concentration ◽  
Highly Sensitive ◽  
No2 Sensor ◽  
Liquid Crystal 5Cb

The paper presents the results of the study of the parameters of the highly sensitive active medium of the NO2 sensor based on a cholesterol-nematic mixture with an admixture of carbon nanotubes. The dependence of the change in the wavelength of the two transmission minima on the NO2 concentration for cholesterol-nematic mixture with single-walled, double-walled and multi-walled nanotubes at different concentrations of nanotubes and two concentrations of nematically liquid crystal 5CB were obtained. It is established that by changing the ratio between the concentrations of nanotubes and nematic liquid crystals, it is possible to obtain mixtures that have the maximum spectral sensitivity coefficient in a given range of gas concentration.

scholarly journals Functional Smart Dispersed Liquid Crystals for Nano- and Biophotonic Applications: Nanoparticles-Assisted Optical Bioimaging

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
N. V. Kamanina ◽  
S. V. Likhomanova ◽  
Yu. A. Zubtcova ◽  
A. A. Kamanin ◽  
A. Pawlicka
Keyword(s):  
Carbon Nanotubes ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Solid Substrate ◽  
Holographic Recording ◽  
Self Assembling ◽  
Aligned Carbon Nanotubes ◽  
Vertically Aligned ◽  
Crystal Cells ◽  
Modified Functional

Functional nematic liquid crystal structures doped with nano- and bioobjects have been investigated. The self-assembling features and the photorefractive parameters of the structured liquid crystals have been comparatively studied via microscopy and laser techniques. Fullerene, quantum dots, carbon nanotubes, DNA, and erythrocytes have been considered as the effective nano- and biosensitizers of the LC mesophase. The holographic recording technique based on four-wave mixing of the laser beams has been used to investigate the laser-induced change of the refractive index in the nano- and bioobjects-doped liquid crystal cells. The special accent has been given to novel nanostructured relief with vertically aligned carbon nanotubes at the interface: solid substrate-liquid crystal mesophase. It has been shown that this nanostructured relief influences the orienting ability of the liquid crystal molecules with good advantage. As a result, it provokes the orientation of the DNA. The modified functional liquid crystal materials have been proposed as the perspective systems for both the photonics and biology as well as the medical applications.

Structural evolution and dielectric properties of suspensions of carbon nanotubes in nematic liquid crystals

2017 ◽  
Vol 19 (25) ◽  
pp. 16456-16463 ◽  
Author(s):  
S. Tomylko ◽  
O. Yaroshchuk ◽  
O. Koval'chuk ◽  
N. Lebovka
Keyword(s):  
Carbon Nanotubes ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Dielectric Properties ◽  
Nematic Liquid Crystal ◽  
Nematic Liquid Crystals ◽  
Structural Evolution ◽  
Percolation Transition ◽  
Electrical Percolation

Smeared electrical percolation transition in suspensions of carbon nanotubes in nematic liquid crystal was revealed. Four stages of structural evolution were identified.

scholarly journals Lyotropic Liquid Crystals from Colloidal Suspensions of Graphene Oxide

Crystals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 455 ◽  
Author(s):  
Adam P. Draude ◽  
Ingo Dierking
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Colloidal Particles ◽  
Colloidal Suspensions ◽  
Lyotropic Liquid Crystals ◽  
Nanoscience And Nanotechnology ◽  
And Behavior

Lyotropic liquid crystals from colloidal particles have been known for more than a century, but have attracted a revived interest over the last few years. This is due to the developments in nanoscience and nanotechnology, where the liquid crystal order can be exploited to orient and reorient the anisotropic colloids, thus enabling, increasing and switching the preferential properties of the nanoparticles. In particular, carbon-based colloids like carbon nanotubes and graphene/graphene–oxide have increasingly been studied with respect to their lyotropic liquid crystalline properties over the recent years. We critically review aspects of lyotropic graphene oxide liquid crystal with respect to properties and behavior which seem to be generally established, but also discuss those effects that are largely unfamiliar so far, or as of yet of controversial experimental or theoretical outcome.

scholarly journals Tunable scattering from liquid crystal devices using carbon nanotubes network electrodes

Nanoscale ◽  
2015 ◽  
Vol 7 (1) ◽  
pp. 330-336 ◽  
Author(s):  
Ammar A. Khan ◽  
G. Dinesha M. R. Dabera ◽  
Haider Butt ◽  
Malik M. Qasim ◽  
Gehan A. J. Amaratunga ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Optoelectronic Devices ◽  
Single Walled Carbon Nanotubes ◽  
Single Walled Carbon ◽  
Liquid Crystal Devices ◽  
Rare Combination ◽  
Walled Carbon Nanotubes

We demonstrate a rare combination of polymer wrapped single walled carbon nanotubes with liquid crystals to produce switchable optoelectronic devices.

scholarly journals Length Bidisperse Carbon Nanotubes Dispersions in Thermotropic Liquid Crystals

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
V. Popa-Nita ◽  
S. Buček
Keyword(s):  
Carbon Nanotubes ◽  
Free Energy ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Nematic Liquid Crystal ◽  
Volume Fraction ◽  
Coupling Term ◽  
Nematic Ordering ◽  
Thermotropic Liquid Crystals ◽  
Phase Ordering

We study nematic liquid crystal driven alignment of carbon nanotubes dispersed in them. We extend the mesoscopic model presented in (P. Van der Schoot et al. 2008, V. Popa-Nita, and S. Kralj 2010) including the effect of length bidispersity of carbon nanotubes. The free energy of the mixture is written as the sum of the Doi free energy for lyotropic nematic ordering of the two carbon nanotubes types, the Landau-de Gennes free energy for the thermotropic ordering of liquid crystal, and the coupling term between liquid crystal molecules and carbon nanotubes. The phase ordering of the mixtures is analyzed as a function of volume fraction, the strength of coupling, and the temperature.

Electric-Field Effects in Dilute Suspensions of Carbon Nanotubes Dispersed in Nematic Liquid Crystals

2010 ◽  
Vol 428-429 ◽  
pp. 173-181 ◽  
Author(s):  
Muklesur Rahman ◽  
Wei Lee
Keyword(s):  
Carbon Nanotubes ◽  
Liquid Crystal ◽  
Carbon Nanotube ◽  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Colloidal Particles ◽  
Liquid Crystal Display ◽  
New Physics ◽  
Colloidal System ◽  
Colloidal Systems

Colloids composed of liquid-crystal hydrosols exhibit a rich set of interesting phenomena. The coupling between liquid-crystalline media and colloidal particles plays an essential role leading to an abundant source of new physics. In the last few years, peculiar behaviors of carbon-nanotube-doped calamitic liquid crystals have attracted considerable attention. This paper provides a brief introduction to this alluring subject for its on-going research development in this laboratory. First presented are our current understandings of the nematic colloidal system comprising carbon nanotubes and of their possible orientation and dynamics under the application of an external field. Various electro-optical and electrical properties of a liquid-crystal display rectified by the nanoscale carbonaceous guest are then addressed to a larger extent. Dielectric relaxation obtained from a nematic impregnated with carbon nanotubes is also discussed. With historical significance for the dawn of the liquid-crystal–carbon-nanotube research, several important findings of enhanced nonlinear optical properties in typical nematic mesomaterials consisting of suspended nanotubes are delineated. With the new colloidal systems of elongated nanoscale solids dispersed in anisotropic fluids in the mesophase, many new intriguing phenomena are awaiting theoretical and experimental explorations. Collaborations are called to draw attention of interested theoretical physicists, in particular.

Photoluminescent Properties of Composites Based on the Liquid Crystal 5CB with Carbon Nanotubes

2017 ◽  
Vol 83 (6) ◽  
pp. 990-995 ◽  
Author(s):  
T. V. Bezrodna ◽  
G. V. Klishevich ◽  
V. V. Nesprava ◽  
V. I. Melnyk ◽  
A. N. Roshchin ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Liquid Crystal ◽  
Liquid Crystal 5Cb ◽  
Properties Of Composites
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