INDUCTION OF LYOTROPIC-CHOLESTERIC PHASES IN LYOTROPIC-NEMATIC PHASES BY ADDITION OF OPTICALLY-ACTIVE COMPONENTS

The formation of lyotropic mesophases, in particular the rod-like and disclike nematic phases in the systems hexadecyldi-methylethylammoniumbromide/water/aliphatic alcohol (n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol) was examined. The ternary phase diagrams were established and the positions of the corresponding phase regions in the phase diagrams were determined. Lyotropic-cholesteric phases were induced in the lyotropic-nematic phase regions by addition of optically active components such as cholic acid, desoxycholic acid, lithocholic acid, cholesteryl formiate, cholesteryl acetate and L- and D-tartaric acid. When subjected to the influence of a magnetic field, the lyotropic-cholesteric phases show various textures. The so-called ''spaghetti-like'' texture has been used for determining the pitch length. The pitch length is dependend on the chemical structure and concentration of the optically active components.