An adiabatic scanning calorimetry study of a chiral liquid crystal tolane with blue phases and twist grain boundary phases

Autor:	Jan Thoen, Gilles Sigaud, Peter Jamée, M Young, Guido Pitsi, Min-Hui Li, HT Nguyen
Rok vydání:	1998
Předmět:	Phase transition Materials science Liquid crystal Phase (matter) Enthalpy Analytical chemistry General Materials Science Grain boundary General Chemistry Calorimetry Condensed Matter Physics Adiabatic process Heat capacity
Zdroj:	Liquid Crystals. 25:387-391
ISSN:	1366-5855 0267-8292
DOI:	10.1080/026782998206191
Popis:	High resolution adiabatic scanning calorimetry (ASC) was employed to study the phase behaviour exhibited by the chiral liquid crystal material (R)-1-methylheptyl 3-fluoro-4- (3-fluoro-4-octadecyloxybenzoyloxy)tolane-4-carboxylate (FH/FH/HH-18BTMHC). We report on the heat capacity of the different phases and phase transitions as well as the enthalpy changes of the material showing a phase sequence Cr-SmC*-TGBC-TGBA-BPI-BPIIBPIII-I. While the presence of the BPI phase was observed in previous DSC studies only on cooling the sample, our ASC measurements detected this phase also in the heating runs at sufficiently slow scanning rates. Indications of smectic order still present in the blue phases, as recently reported from X-ray scattering experiments, are also observed.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::5cc2d8fb7242676c46f3014d9948b35e https://doi.org/10.1080/026782998206191 Zobrazit plný text záznamu