Phase Behavior in Freely Suspended Films of Polar Liquid Crystals
Keith Hedlund
(University of Colorado–Boulder)
Research Project Description.
Preliminary studies of the highly polar organic molecule DIO revealed a mysterious liquid crystal phase between the nematic and ferroelectric nematic phases. X-ray diffraction studies showed that this phase—dubbed the M2 phase—was both layered and highly tilted, suggesting the possibility of a new smectic phase. We report on studies of freely suspended films of this material in the M2 phase using reflected ligh microscopy and a variety of light polarizations to characterize its structure.
MacLennan Lab
Joseph MacLennan received his B.Sc. (Hons.) in Physics and Electronics from Rhodes University, South Africa, in 1980, and his Ph.D. in Physics from the University of Colorado in 1988. He then spent five years in the Physical Chemistry Department at the University of Mainz in Germany, the first two as a Humboldt Postdoctoral Fellow. In 1994, he returned to Boulder to rejoin the Liquid Crystal Physics group at the University of Colorado. His research interests center on determining the structure and electro-optic properties of liquid crystal materials, including bent-core and ferroelectric smectics and ferromagnetic colloids, and on understanding the textures and phase transitions of freely-suspended liquid crystal films, including the interactions and ordering behavior of topological defects and islands and the 2-D hydrodynamics of liquid droplets.