Chiral effects of blue phase stabilisation of a binaphthyl derivative

ISSN： 0267-8292

Source： Liquid Crystals, Vol.38, Iss.3, 2011-03, pp. : 303-307

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

We have recently reported a binaphthyl liquid crystal exhibiting on cooling a cubic blue phase over a wide temperature range. On heating, however, a chiral nematic phase appeared in place of the blue phase. To elucidate the origin of blue phase stabilisation we have prepared a homologous series of binaphthyl derivatives possessing two 2,3-difluoro-1,4-diphenylbenzene units and have investigated the phase transition behaviour and helical twisting power. A binaphthyl derivative exhibiting the blue phase was found to induce helical twist inversion in a chiral nematic mixture with a host liquid crystal, whereas other compounds without the blue phase induced short helical pitches independently of temperature. The blue phase material is thought to have two possible origins for its twisting power, which are able to stabilise the double-twist structure of the phase.