Phase transitional behavior of swollen thermotropic liquid crystals studied by 2H-NMR spectroscopy and density measurement

Abstract

We have investigated the molecular alignment and the phase transition behavior of a mixture composed of a typical thermotropic smectic liquid crystal (4-(methylheptyloxycarbonyl) phenyl 4'-octyloxybihenyl-4-carboxylate:S-MHPOBC) and alkanes (octane and hexane). The myelin texture is observed in the mixture in the temperature range where the emergence of mesophases is confirmed by DSC. X-ray measurements show that the mesophases are smectics. While the layer thickness is thicker than 4.5 nm, it decreases with increasing temperature.