Responses of Discotic Liquid Crystals to Mechanical, Magnetic, and Electrical Fields

The responses of columnar discotic liquid crystals to mechanical, magnetic, electrical, and surface fields are reviewed. Alignment in thin open films and in confined samples such as small droplets, fibers, grooves, and capillaries are examined in detail. The principles that underlie their commercially significant lubrication properties are outlined. At the molecular level, detailed studies of mesogen dynamics using dielectric and nuclear spin relaxation spectroscopies provide insights into the translational and reorientational motion. The mechanism of electronic conduction is discussed within the context of our understanding of conduction in other molecular materials together with the factors governing charge carrier mobility. These materials combine the easy processability of amorphous molecular solids with charge mobilities approaching those in crystalline solids. This unique combination of properties opens the door to a variety of potential applications. Keywords: columnar mesophases; surface anchoring; lubricants; magnetic fields; E-Fields; electronic conductors