Calorimetric study of the cubic mesogen,ACBC(16) |
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Authors: | Michio Sorai Corresponding author Kazuya Saito Corresponding author Tadahiro Nakamoto Mayumi Ikeda Yuri G. Galyametdinov Irina Galyametdinova |
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Affiliation: | 1. Research Center for Molecular Thermodynamics, Graduate School of Science , Osaka University , Toyonaka, Osaka 560-0043, Japan;2. Institut für Physikalische Chemie, Fachgebiet Kondensierte Materie , Technische Universit?t Darmstadt , Petersenstrasse 20, D-64287 Darmstadt, Germany;3. Kazan Physical-Technical Institute , Russian Academy of Sciences , Sibirsky Tract 10/7, 420029 Kazan, Russia |
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Abstract: | The heat capacity of the cubic mesogen ACBC(16) was measured between 16 and 500?K by adiabatic calorimetry. As well as the known condensed phases, a new crystalline phase was found to undergo a glass transition at around 165?K. Phase transitions between crystal, SmC, cubic, and isotropic liquid phases took place at 399.16, 431.15, and 474.30?K, respectively. As in the case of ANBC, a broad hump was observed in the heat capacity of the isotropic liquid phase. The first order nature of the SmC–cubic phase transition was confirmed for the first time by the observation of supercooling of the cubic phase. The broad hump in the isotropic liquid phase was shown to extend to a low temperature side if the isotropic liquid was supercooled, suggesting that the event occurring at the hump is not directly related to the cubic–isotropic liquid phase transition. |
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Keywords: | azoester H-shaped smectic A smectic C symmetrical dimers |
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