The Metabolemeter IV-Phase Transitions of Binary Mixtures of Mesogens Detected on About One Milligram Samples

Abstract

For perfet solutions, thermobarograms for binary mixtures of mesogens enclosed in a metallic cell be calculated. Experimental tests are performed with the metabolemeter on two mixtures of 4-methoxy-4′ -ethytolane and 4-methoxy-4′-n-nonyltolance using about one milligram samples. The experimental thermobarograms agree with calculations and allow very easily the detection of all the transformations. Moreover, for pure 4-methoxy-4'-ethylotolane, the volume change for the virtual nematic-liquid transition can be deduced. The methos is then used to determine the (I-methyl)-heptyl terephthalidene bis amono cinnamate and bis-4-n-heptoloxybenzylidene phenylene amine phase diagram; the microscopic observations about the existence of a mesophase which doesn't exist for pure compounds are considered; the concentration existence domain of that mesophase is determined.