Interplay between Melt and Cold Crystallization in a Smectic Liquid Crystal, 4-Pentylphenyl 4-(<i>trans</i>-4-Pentylcyclohexyl)benzoate
Tomasz Rozwadowski, Yasuhisa Yamamura, Kazuya Saito
Abstract
In this study, we apply differential scanning calorimetry (DSC) and polarizing microscopy (POM) to elucidate the interplay of crystallization mechanisms controlling the tendency for melt and cold crystallization from the partially ordered smectic B phase in 4-pentylphenyl 4-(trans-4-pentylcyclohexyl)benzoate (5CPB5) mesogen. For this purpose, we pay attention to the kinetics of nonisothermal crystallization revealed by several complementary approaches, including Ozawa, Mo, and the isoconversional method. Additionally, we adopt the Hoffman–Lauritzen theory for analyzing the temperature dependence of crystallization activation energy, allowing us to describe the multistep crystallization of the smectic B mesophase. Our investigation shows the possibility of designing the mechanism controlling the different crystallization paths. Moreover, we demonstrate the ability to switch the dimensionality of crystal growth by modifying the dominance of molecular mobility through the experimental rate.