Influence of Cooling Rates on Phase Transitions of Bent-Core Liquid Crystal 1,3-Phenylene-bis[4-(hexylcarboyloxyl)benzylideneamine]

Abstract

The influence of cooling rate on the phase transitions of a three-benzene-ring containing bent-core liquid crystal 1,3-phenylene-bis[4-(hexylcarboyloxyl)benzylideneamine] has been investigated by means of differential scanning calorimetry and polarized optical microscopy. Our results show that the cooling rates in the second cooling run pose significant effects on the phase transitions of the bent-core liquid crystal despite the cooling rates in the first cooling run pose little effects on the phase transitions. In the second cooling run, the banana phases survived only when the cooling rates were in the range of 14~15oC/min whereas both slow cooling rates which were less than 13oC/min and fast cooling rates which were higher than 16oC/min made the banana phases disappeared.