Crystallization upon thermal annealing of a glass-forming liquid crystal in the nematic regime

• Published in: Applied physics letters Vol. 66; no. 17; pp. 2212 - 2214
• Main Authors: Mastrangelo, John C., Blanton, Thomas N., Chen, Shaw H.
• Format: Journal Article
• Language: English
• Published: 24-04-1995
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.113170

As an example of a novel class of glass-forming liquid crystals, compound (I) was synthesized and characterized to possess a nematic mesophase between Tg and Tc as the pristine crystal was heated beyond its Tm followed by quenching to below room temperature. Differential scanning calorimetry (DSC) and x-ray diffraction techniques were employed to investigate its morphological stability. It was found that the nematic mesophase persists upon annealing for a period of up to 22 h without the appearance of new phases. However, after annealing in the nematic regime over a longer period of time, thermally activated phase transformations were observed, resulting in a new crystalline phase plus the pristine crystalline phase based on DSC thermal transition data and x-ray diffraction patterns.