Effect of the surfaces on orientational properties and peculiarities of phase transitions in thermotropic nematics

Abstract

In this work, the effect of thin films on the orientational, thermotropic and optical properties and on the peculiarities of the nematic–isotropic liquid phase transition has been carried out.The planar textures of MBBA+EBBA eutectic mixture on the surfaces coated with Al2O3and ZrO2thin films have been obtained. The optical and thermodynamical parameters of the obtained, oriented textures have been determined. The effect of thin films on the temperature width of heterophase region and on the nematic–isotropic liquid phase transition temperatures has been investigated. The shift of the phase transition temperatures and the change of the temperature width of the heterophase region have been revealed.For the analysis of peculiarities of the nematic–isotropic liquid phase transition and the heterophase regions of this transition, the mean field theory has been used.