Influence of the molecular structure on the photoanisotropic properties ofazodyes

The influence of azo-dye molecular structure, especially of the terminal su bstituents on the photo-induced anisotropic properties of their films was i nvestigated. In order to avoid the solubility of azo-dyes in liquid crystal s (LC), their sodium salts were synthesised. The photoinduced anisotropic p roperties were studied both as individual substances and as mixtures with p olyamide acid (PAA). The pretilt angles of nematic liquid crystals oriented by photoanisotropic films of azo-dye with PAA were measured.