Structural and calorimetric investigations on nonaqueous liquid crystals and gel phases in the binary system K-behenate/glycerol

Two mixtures of the binary system K-behenate/glycerol, x(KC22) = 0.30 and 0 .50 (x = mole fraction), have been investigated as a function of temperatur e using small-and wide-angle X-ray diffraction (XRD) and differential scann ing calorimetry (DSC). The binary phase diagram based on texture observatio ns using polarizing optical microscopy was confirmed. XRD and DSC measureme nts provided concordant results with respect to the range of the phase regi ons in the phase diagram. Only differences between the DSC curves for risin g and falling temperatures were detected. The recorded XRD and DSC data of the liquid crystals and gel phases observed are also in agreement with prev iously reported investigations on K-soap/glycerol. The C <-> G and G <-> L- alpha phase transitions correlate with a sharp shift in the d value of the first small-angle reflection. The G phase is characterized by a split of th e first small-angle reflections. Also, the position and shape of the wide-a ngle reflections change and the peak intensity is reduced.