Heat Capacity of the Cubic D Liquid Crystal, 4'-n-Alkoxy-3'-nitrobihenyl-4-carboxylic Acid

Abstract

Heat capacities of 4'-n-hexadecyloxy-3'-nitrobiphenyl-4-carboxylic acid were measured with an adiabatic calorimeter in the 13-482K range, and with a DSC in the 470-510K range. Four crystalline phases were found. In the liquid crystal region, S_C - D and D - S_A phase transitions were observed, and a broad heat-capacity anomaly was observed above the clearing point. Thermodynamic quantities associated with the phase transitions were determined.