Time-Resolved X-Ray Diffraction from Liquid Crystalliine Systems: Thermotropic Phase Transitions and the Effect of Applied Electric Fields

Time resolved X-ray diffraction from thermotropic liquid crystalline (LC) materials has been studied in conjunction with standard LC characterization techniques to investigate phase transitions and alignment due to applied electric fields. A more detailed understanding of the kinetics of the interaction between LC systems and applied fields is being sought. Both the effect of electric fields on the inter-molecular structure and the orientation parameter have been evaluated as a function of temperature for LC model compounds. These results are compared to observations of these mesogens in applied electric fields using optical microscopy. Materials of interest include low molar mass distyrylbenzene mesogens which exhibit both nematic and smectic mesophases. Results of investigations of thermotropic polymers will be discussed.