The Polymorphism of Cholesteryl Esters: Differential Thermal and Microscopic Measurements on Cholesteryl Myristate

Abstract

The techniques of differential thermal analysis and photomicroscopy have been combined to eludicate the complex phase relationships and crystallography of cholesteryl myristate. Also, the amount of polarized light rotated by the samples as a function of temperature has been measured at a fixed sample thickness. Cholesteryl myristate exhibits a complex liquid crystal mesophase system on heating. In addition to the phase transformations obtainable on heating, photomicrographs were obtained of the phases which result on subjecting the smectic and cholesteric mesophases to a very low shear. Excellent correlation was obtained between the present work and earlier studies of the myristate ester. The combined instrumental and microscopic method appears to be a valuable tool in the study of subtle phase changes in complex systems.