Effects of layer order on the mobility of mesogenic molecules in SmA liquid-crystalline emulsions

Department of Physics, Graduate School of Science, Kyoto University - Kita-Shirakawa, Sakyo, Kyoto 606-8502, Japan

Received: 6 November 2015
Accepted: 15 March 2016

Abstract

We fabricate smectic-A liquid-crystalline emulsions (SmA-LCEs) in which monodisperse 8CB-swollen micelles are dispersed in water. Synchrotron X-ray measurements reveal that the correlation length of the layer order in LCEs cannot diverge at the nematic (N)-SmA transition, and the saturated length linearly increases with the increase in the diameter of LC-swollen micelles. Moreover, we investigate the permeation of 7CB N molecules into 8CB SmA-LCEs by measuring the enhancement of the depolarized light scattering intensity due to the shift of the SmA-N phase transition, and confirm that the layer order suppresses the mobility of LC molecules in LCEs similar to the bulk state of SmA LCs. The mobility drastically accelerates near the SmA-N transition temperature due to the continuous extinction of the smectic layer order. The slow permeation process of 7CB is also confirmed via synchrotron X-ray diffraction examining the shrinkage of the smectic layer repeat distance, caused by intercalation of 7CB.