Useful Defects on the Surfaces of Chiral Liquid Crystalline Polymers

Materials found in nature are often classified as being in the liquid, solid or gas state. Some materials such as nematic liquid crystals flow like liquids but orient themselves along a common axis. Chiral nematic crystals additionally form periodical helical structures which leads to selective reflection of light and formation of a number of defects including focal conic domains. Chiral liquid crystalline polymers and oligomers which can vitrify are of special interest because defects formed on their surface can be manipulating in a variety of ways. Changing the temperature or the chemical nature of the surface interface as well as decorating the defects with metal nanoparticles/metallizing the surface allowed for unique patterns. The defects were studied in chiral liquid crystal siloxanes, oligomers and networks, and their formations were studied under an atmosphere of volatile organic compounds and liquid concentrations. Next, the surfaces were decorated and/or metallized by silver and studied under Atomic Force Microscopy. The surface patterns created were found to be very sensitive to changes in the atmosphere of volatile organic compounds. Applications of the metallized liquid crystal polymers are far reaching and can find use to create diffraction gratings and much more.