Thermal properties and chromatographic behavior of a mixture of two liquid crystals

The thermal and chromatographic properties of an equimolecular mixture of two liquid crystals have been investigated. Differential scanning calorimetry showed that the clearing temperature of the mixture is intermediate between the corresponding temperatures for the individual liquid crystals. The melting temperature was lower than the corresponding temperatures for the separate liquid crystals. Polarizing microscopy showed that the liquid crystal phase of the mixture was nematic. The analytical performance of the mixed liquid crystal was investigated by use of different kinds of solute (aromatic hydrocarbons, polycyclic hydrocarbons, phenols, volatile aroma compounds). It seemed that the behavior of the nematic mixture was the same as that of a pure nematic liquid crystal. When separations were performed with the mixture the more elongated isomer (para for positional isomers, trans for geometric isomers) was the most retained solute.