The Metabolemeter: I A New Apparatus to Detect the Phase Transitions of Mesogens

Abstract

For the most organized mesophases, no really efficient routine method to detect phase transitions exists for small quantity. In these cases, the first order phase transitions of a compound enclosed in a metallic cell are occurring with an important pressure increment. In the measure of the pressure versus the temperature, intensive data only occur and miniaturization is possible. A new apparatus (metabolemeter) using this principle is described. Its efficiency was tested on the crystal-mesophase transitions of the two first terms of the alkoxybenzylidene butyl aniline series and of the octylcyanobiphenyl. For these three compounds, the studies of the nematic-liquid transitions show this barometric method is sensitive.