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

Journal Article · Mon Apr 24 04:00:00 EDT 1995 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.113170· OSTI ID:45951

Mastrangelo, J C ^[1]; Blanton, T N ^[2]; Chen, S H ^[1]

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1. Department of Chemical Engineering, Gavett Hall, University of Rochester, Rochester, New York 14627 (United States)
2. Analytical Technology Division, Kodak Park, Building 49, Eastman Kodak Company, Rochester, New York 14652-3712 (United States)

As an example of a novel class of glass-forming liquid crystals, compound (I) was synthesized and characterized to possess a nematic mesophase between {ital T}{sub {ital g}} and {ital T}{sub {ital c}} as the pristine crystal was heated beyond its {ital T}{sub {ital m}} 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.

• Research Organization: University of Rochester
• DOE Contract Number: FC03-92SF19460
• OSTI ID: 45951
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 17 Vol. 66; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
CRYSTALLIZATION
HEAT TREATMENTS
LIQUID CRYSTALS
MORPHOLOGY
ORDER-DISORDER TRANSFORMATIONS
PHASE STABILITY
PHASE TRANSFORMATIONS
SYNTHESIS