Oriented and non-oriented textures of nematic liquid crystals: Comparative peculiarities of the thermotropic behavior

In this work the thermotropic behavior of various types of textures in monomorphic nematic liquid crystals has been investigated in detail. Thread-like, homeotropic oriented and planar oriented textures of MBBA, MBBA + EBBA and 5CB liquid crystals have been used. Temperatures of the direct nematic mesophase – isotropic liquid and reverse isotropic liquid – nematic mesophase phase transition, the thermal and linear widths of the heterophase regions for these transitions have been determined with high accuracy. Differences in temperatures of the direct and reverse phase transitions and differences in the thermal and linear widths of the heterophase regions of these transitions for non-oriented and oriented textures have been found. These differences are connected with differences in the anchoring energy between liquid crystalline molecules and reference surfaces for the non-oriented, homeotropic oriented and planar oriented textures.