Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, Vol.241, 103-117, 1994
Structures of Point Integer Disclinations and Their Annihilation Behavior in Thermotropic Liquid-Crystal Polyesters
A schlieren texture composed of integer strength point disclinations has been observed in a thermotropic liquid crystal polymer. The director patterns about positive and negative disclinations are studied by optical microscopy and scanning electron microscopy. Defects are located at the specimen-air interface and occur due to the different boundary conditions of the Liquid crystal at the air and glass interfaces. The annihilation behavior of these integer defects, created by a temperature-drop procedure from an initial isotropic state into the nematic state, was also investigated. It was found the relation between pair separation, D, and annihilation time, t(0), was D alpha (t(0) - t)(0.5), which was in good agreement with the recent scaling solution prediction by Pargellis et al.(1)