STUDY OF STRUCTURAL PATTERNS EXHIBITED BY A BINARY MIXTURE OF SMECTIC AND CHOLESTERYL COMPOUNDS

The binary mixture of Cholesteryl ethyl corbonate (CEC) and Terephthal-bis-p-n-Tetradecylaniline (TB14A) exhibits a twisted grain boundary (TGB) phase and smectic polymorphic phases. The mixture exhibits TGB-A and TGB-C phases in different concentrations and at different temperatures. Mixtures with higher concentrations of TB14A exhibit I – Ch - TGB-A - TGB-C - Sm A - Sm I - Sm F phases sequentially when the specimen is cooled from its isotropic melt. The existence of different TGB phases and polymorphic smectic phases are confirmed by DSC and optical microscopic studies.