Saturation effect for dependence of the electrical conductivity of planar oriented nematic liquid crystal 6CB on the concentration of Cu7PS6 nanoparticles

Abstract

Abstract. The influence of Cu 7 PS 6 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 10 1 …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.

Nanoparticle-Enabled Ion Trapping and Ion Generation in Liquid Crystals

“…An increase in the electrical conductivity of 6CB nematic liquid crystals through doping them with Cu 7 PS 6 nanoparticles was recently reported by Kovalchuk and coworkers [36]. An interesting feature of the observed effect was the saturation of the increase in the electrical conductivity at higher concentrations of nanoparticles [36]. The concentration of mobile ions can be estimated through =…”

“…In other words, the origin of these ions can be associated with the chemical structure of Cu 7 PS 6 nanoparticles and the possibility of their selfdissociation rather than with ionic contaminants originated during their preparation and handling. The dissociation of Cu 7 PS 6 nanoparticles resulting in the generation of copper ions can be reasonably expected for this type of materials [36].…”

“…Ion-related effects of nano-objects in liquid crystals were reported in many publications reviewed in a recent paper [ [39] and references therein]. Different research groups reported that various types of nanomaterials (metal [39][40][41][42][43], semiconductor [35,44], dielectric [34,36,45], ferroelectric [46][47][48][49][50][51] magnetic [52], and carbon-based [53][54][55][56]) changed the concentration of ions in liquid crystals in different ways. Despite the variety of existing experimental results on ions 2 Advances in Condensed Matter Physics and nano-objects in liquid crystals, they can be broadly categorized into the following groups: (i) papers reporting the decrease in the concentration of ions in liquid crystals (the ion trapping regime); (ii) publications presenting the increase in the concentration of ions (the ion generation regime); (iii) the combination of both ion trapping and ion generation regimes (depending on the concentration of nanodopants in liquid crystals) [39].…”

Influence of anion substitution on electrical conductivity of composites based on liquid crystal with Cu6PS5X (X = I, Br) nanoparticles

“…To significantly expand the limits of practical application of LC, it is necessary to be able to predictably change their properties. One of the methods for expanding the functional properties of LC is introduction of various types of nanoparticles [1][2][3][4]. As we have shown in Refs.…”

“…As we have shown in Refs. [1][2][3][4], significant changes in the properties of LC are observed when introducing superionic nanoparticles. The introduction of Cu 6 PS 5 I nano-particles into 6CB leads to an increase in conductivity by almost two orders of magnitude, which is caused by dissociation of nanoparticles in LC with formation of Cu ions [1].…”