The molecular arrangement in a liquid crystal (LC) film differs in the bulk compared to surfaces and interfaces. An LC film deposited onto a grooved substrate experiences a competition between the aligning forces at the LC-air interface, which force the molecules to align normal to the surface, and aligning forces at the LC- substrate interface, which forces the molecules to align parallel to the plane of the substrate. In previous studies on smectic A liquid crystal films, a critical thickness was measured beyond which the long-range aligning forces from the groove interface dominate over the short-range aligning forces imposed by the air-LC interface. There is a range in thicknesses, which spans approximately 10um, where the competition between short-range and long-range aligning forces is most pronounced. The aligning forces are responsible for many pretransitional phenomena as well as surface memory effects inside the films. In this project, the unstable region just above the critical thickness in smA droplets will be studied as a function of temperature to ascertain the interplay between short and long range aligning forces. Attention will be paid to the region immediately above the LC-solid substrate interface. Interactive activities consist of the following: (1) teaching a graduate course in liquid crystal physical properties, taught as part of the Chemical Physics Interdisciplinary program at Kent State University; and (2) organizing outreach activities for high school students and first and second year college students. This second activity will include visits to area schools as well as the development of demonstration kits. A major goal is to convey the interdisciplinary nature of liquid crystal research and of science in general.
