The Structure of Mesophases of Binary and Multicomponent Mixtures of some Cholesteric Liquid Crystals

We present the results of the study of binary and multicomponent mixtures of cholesteryl enanthate with cholesteryl nonanoate and cholesteryl formiate. The aim of the study is the preparation of the system with phase transition temperature close to room temperature. Phase diagrams of binary mixtures are formed on the basis of data obtained by the optical microscopy and DS calorimetry and the shift of phase transition points of order 30-50° with respect to initial components was established. In the case of three- and four-component mixtures, we have identified the presence of enantiomorphic phase transitions of smectic and cholesteric type respectively. X-ray diffraction data have enabled the characterization of the structure of smectic or cholesteric mesophase and the calculation of molecular parameters: apparent length of the molecules l and the average intermolecular distance (D).