Isothermal and Non-Isothermal Study of 8OCB Liquid Crystal using DSC and Logger Pro.

The focus of this research is to explore the isothermal and non-isothermal properties of 4-oxy-4'-cyano­biphenyls (8OCB) Liquid Crystal (LC). This paper reports on the data collected from the technique of DSC and the behavior of 8OCB when heated 0°C/100°C and cooled 100°C/-40°C for ramp rates of 5, 10, and 20 °C/min. The thermal speed, acceleration, and jerk we calculated using the program LoggerPro to further understand the molecules' behavior to observe the effects of repetitive heating and cooling on 8OCB and how that would relate to LC’s use in Liquid Crystal Displays (LCDs), specifically looking at if there is any type of degradation in the nematic phase. This data can be used to compare to data collected on the heat flow during, before, and in between the heating and cooling phases to understand how the molecule is further affected by increased ramp rates of constant heating and cooling at times when the temperature is not changing. The isothermal segments of the DSC were seen to have increased heat flow as the ramp rate was increased which is important to consider when applying to the application of nematic LCDs.