Liquid crystal supermolecules stabilizing an optically isotropic phase with frustrated molecular organization

Abstract

Cubic and blue phases have attracted a significant amount of attention because of their unusual phase structures with optical isotropy and because of their application to ion transfer in the cubic phase and to electrooptical switching in the blue phase. However, the driving forces for the frustrated liquid-crystalline phases differ from those for a conventional liquid-crystalline phase composed of rod-like molecules. We show that preprogrammed liquid-crystalline supermolecules can stabilize frustrated molecular organization in optically isotropic phases. Competition between steric effects caused by a taper-shaped oligomeric structure and segregation effects attributable to hydrocarbon/fluorocarbon amphiphilicity produces fluctuation of the layer structure, inducing the lamellar-to-cubic phase transition. Cooperation between inherent molecular chirality and the chirality-induced twist conformations of the mesogenic units stabilizes double-twist structures in blue phases. Furthermore, we demonstrate high-transmittance, sub-millisecond responses and hysteresis-free switching in a room temperature amorphous blue phase stabilized by a liquid crystal supermolecule. © 2012 The Society of Polymer Science, Japan (SPSJ) All rights reserved.