MODULATED DIFFERENTIAL SCANNING CALORIMETRY - TRANSITIONS BETWEEN MONOTROPIC AND ENANTIOTROPIC PHASES OF A CHOLESTERIC LIQUID-CRYSTAL

The Modulated Differential Calorimetry (MDSC) is applied to the determ ination of the reversibility in the cholesteryl chloride, which presen ts a cholesteric monotropic phase between the isotropic and crystallin e states. The experimental modulation parameters that govern this meth od i.e. frequency, amplitude and heating/cooling rate, are determined. MDSC curves and complementary thermomicroscopical observations assign melting, crystallization and liquid cholesteric transition as 'non re versing', and clarification as 'reversing'.