Phase Transition and Molecular Orientational Studies on Nematic Dimmer and Cholesteric Materials

Abstract

The binary mixture of nematic dimmer and cholesteric compounds viz., cholesteryl nonanoate (CN) and 1,7-bis-4-(4′-cyanobiphenyl) heptane (CB7CB) exhibits very interesting liquid crystalline phase’s at large range of concentrations and temperature. The concentrations with lower/higher percentage of CB7CB exhibit cholesteric and reentrant smectic-A phases sequentially when the specimen is cooled from its isotropic phase. The molecular tilt and birefringence have been discussed in the region of smetic-A and smectic-C phases, respectively at different temperature. The temperature variations of optical anisotropy have also been discussed.

Keywords: Optical texture; Birefringence; layer spacing; Molecular orientation

Cite this Article T.N. Govindaiah. Phase Transition and Molecular Orientational Studies on Nematic Dimmer and Cholesteric Materials. Research & Reviews: Journal of Physics. 2018; 7(1): 1–4p.