Molecular Orientation in Liquid Crystalline Side Chain Polymers Doped with Dichroic Dye as Studied by Optical Spectroscopy Methods

Abstract

The polarized absorption and emission spectra of fluorescent stilbene dye dissolved in two side chain liquid crystalline polysiloxanes have been recorded as a function of temperature in the mesomorphic and glassy phases. From these spectra the order parameters <P₂> and <P₄> as well as the orientational distribution function of the side mesogenic groups have been estimated. The results have been compared with the data obtained for low molecular weight liquid crystal by using the same optical methods.

Key Words:

• liquid crystal
• dichroic dye
• absorption
• fluorescence
• orientational order