Properties of Guest-Host Systems with Higher Concentrations of Pleochroic Dyes

In this paper we report on the influence of dissolved pleochroic dyes as well on the dye order parameter as on the clearing and melting point of liquid crystalline host as a function of concentration. The investigations of two different anthraquinone dyes in commonly used host systems (Biphenyls, PCHs and CCHs) show, that the order parameter S decreases with increasing dye-concentration comparable for all systems. The influence on the clearing point is different. An increase of the clearing point as well as a decrease has been observed, depending on the used host system. The melting point is influenced in the expected manner (freezing-point depression).