Since the First International Congress on Liquid Crystals (Lcs), held at Kent State University, OH, USA, in 1965, the implications of these systems associated with various aspects of telecommunications, laser, display, automobile, aerospace technologies, thermo-optics, medicine and biology have been the subject of considerable debate among researchers, scientists and engineers. Indeed, LCs, being a unique mesomorphic phase of matter, combine properties of both solids (long-range orientation order, manifestations of Bragg diffraction, etc.) and liquids (fluidity, viscosity, etc.). Important features of LCs are weak dispersion forces between organic molecules and strong orienting fields. An intrinsic characteristic of the organic liquid crystal state is unidirectional (nematic structure) or bidirectional (smectic structure) ordering,.
