Nonequilibrium Phenomena in Liquid Crystals

This paper summarizes a talk presented at the April NATO ASI on Spatiotemporal Chaos in Complex Fluids, in Santa Fe, NM. The paper gives reasons that make complex fluids good material systems for conducting experiments on pattern formation and other nonequilibrium phenomena. Much of the discussion focuses on the different phenomena observed in solidification and how the increasing complexity of fluid systems decreases the velocity scale for achieving "rapid" solidification. Five systems are compared to illustrate this point: simple fluids, simple alloys, thermotropic liquid crystals, lyotropic liquid crystals, and diblock copolymers. Finally, an example is given of the kinds of transitions that may be observed in rapid solidification.