| Experimental investigations of liquid crystalline phases and magnetically-levitated liquid bridges are conducted. In liquid crystal experiments, the electric-field induced transition from the anticlinic phase to the synclinic phase is examined using electrooptic techniques. Two kinds of measurements are made: the velocity of synclinic solitary waves invading the anticlinic phase, and, the threshold electric field as a function of temperature and enantiomeric excess, X. It is found that, for small X, the phase boundary curve exhibits a reentrant synclinic phase with decrease in temperature; while for large X, no reentrant synclinic phase is observed. A phenomenological theory that accounts for layer-layer interactions is discussed to explain these results.; In other experiments, electrooptic measurements are made on a novel lamellar nematic phase in which the mesogens lie in the lamellae, separated by partially perfluorinated side chains. It is found that the twist elastic constant is more than an order of magnitude smaller than that of three-dimensional nematics, a consequence of the greatly weakened interactions between the spatially separated lamellae. Furthermore, studies on refractive indices of the lamellar isotropic and lamellar nematic phases suggest a different lamellar phase structure.; In magnetically-levitated liquid bridge experiments, transient dynamics of liquid bridges are examined for different surfactant concentration. It is found that relaxation time for the liquid bridge with surfactant concentration below the Critical Micelle Concentration (CMC) is lower than that of the bridge with surfactant concentration above CMC. This result is explained using capillary wave damping and surfactant squeeze-out phenomena. Additionally, two cylindrical liquid bridges (with a conduit to facilitate flow of liquid from one bridge to the other) are levitated and their stability limit is measured as a function of slenderness ratio. Stability limit measurements are in agreement with theoretical predictions. |
