Phase Behavior and Heat Capacity of 14PCF, a Polycatenar Mesogen Having a Perfluorinated Moiety

Abstract

Heat capacity of the title compound was measured by adiabatic calorimetry on bulk sample below 400 K. The as-prepared crystal is metastable around its melting temperature to the cubic phase. The cubic phase is also metastable. There is the other, thermodynamically stable crystalline phase, which undergoes a phase transition below room temperature. The as prepared crystal shows below room temperature a trapezoidal anomaly in temperature dependence of heat capacity. The thermal effects are very small in the Col - SmAd and SmAd - IL phase transitions as previously observed through DSC experiments. An anomalous increase in heat capacity is observed a few K below the SmAd - IL phase transition, around which the layer spacing was reported to start decreasing.