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

Z.M Mykytyuk,V.V Petryshak,I.T Kogut,M.V Vistak

doi:10.15330/pcss.22.3.426-431

Abstract

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.

Highlights

Nitrous oxide (NOx) is one of the most harmful gaseous environmental pollution
Nitrous monoxide oxidizes in the atmosphere to nitrogen dioxide (NO2), which is one of the main components of surrounding air pollution that affects the human health
As the carbon nanotubes are highly sensitive to NO2 and have the ability to change the properties from the sorbed gas [15], so it serves for the investigation of the impact of nitrous dioxide on the spectral properties of nanocomposites based on cholesteric nematic mixture (CNM) doped as single, double and multi-walled carbon

Summary

Introduction

Nitrous oxide (NOx) is one of the most harmful gaseous environmental pollution. Nitrous monoxide oxidizes in the atmosphere to nitrogen dioxide (NO2), which is one of the main components of surrounding air pollution that affects the human health. Let’s note, that recently, a demand on reliable as well as rapid systems for detection of explosive substances because of the increasing of the terroristic threat. Their molecules are mainly organic compounds that can be classified under pressure and concentration of the steam. As the carbon nanotubes are highly sensitive to NO2 and have the ability to change the properties from the sorbed gas [15], so it serves for the investigation of the impact of nitrous dioxide on the spectral properties of nanocomposites based on cholesteric nematic mixture (CNM) doped as single, double and multi-walled carbon. Carbon nanotubes absorb NO2 and as the result the optical characteristics of CNM are changed

Experimental Method

Conclusions

Findings

The maximum shift of the minimum of transmission