Effect of Heating and Cooling on 6cb Liquid Crystal Using DSC Technique

Abstract

In this research, details of the heating and cooling of the liquid crystal (LC) 4-cyano-4'-hexylbiphenyl (6CB) were collected through the use of Differential Scanning Calorimetry (DSC), and then analyzed with Logger Pro. The sample of 6CB was heated from -40 °C to 80 °C and then cooled to -40 °C again at a constant rate of 20 °C/min. DSC provided data for the time, temperature, and heat flow, which was used to calculate thermal speed, acceleration, and jerk, as well as the specific heat capacity at each point. Graphs of this data contain endothermic and exothermic peaks that indicate phase transitions, revealing information such as the enthalpy of the peak and the nematic range. One focus of this study was to compare 6CB to other liquid crystals that are part of the n-alkyl-cyanobiphenyl (nCB) family to see if the difference in tail length affects the behavior of the liquid crystal. Results show that 6CB may be of interest as an alternative to other liquid crystals for liquid crystal displays (LCD).