Electro-Hydrodynamic Instabilities in Main Chain Thermotropic Liquid Crystalline Polyesters

Abstract We have investigated the response behavior of the thermotropic nematic polymer, DDA-9, in an electric field. DDA-9 is composed of regularly alternating moieties and flexible spacers. At a critical threshold voltage, dependent on molar mass, these polymers show the onset of instability. The appearance of a (non-fluctuating) striped pattern (Williams domains) is shown and the time of formation and relaxation of these patterns is investigated as a function of applied Voltage.