Novel chiral liquid crystal organic-inorganic hybrid nanoparticle systems : design, synthesis and investigation

• Main Author: Ichim, Ionut Cameliu
• Other Authors: Mehl, Georg; Lewis, Rob
• Published: University of Hull 2013
• Subjects: 540; Chemistry
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.587042

A first step is taken towards the validation of organic synthesis techniques. Small molecular organic compounds were prepared as intermediates for the liquid crystal materials which exhibit room temperature cholesteric mesophases. These cholesterol based materials were then attached to silsesquioxanes. Both materials have low melting points and low transition temperatures. Phase diagrams, contact and miscibility experiments were performed in order to explain a more complicated cholesteric phase behaviour. The cholesteric mesogens were chemically attached to gold and iron/platinum nanoparticles. For all end materials exhaustive characterisation methods were applied. The questions that were tried to be answered were related to the attachment of cholesterol based mesogens to silsesquioxane cores. Furthermore, the organic-silicon hybrid systems were used as a model for the mesogen covered gold and iron/platinum nanoparticles. Cholesterol based liquid crystals with chiral nematic mesophase at room temperature were obtained. Hybrid systems with very short pitch cholesteric phase and low transition temperatures were also prepared. A new method for preparing gold nanoparticles was implemented. The present results indicate that it is possible to prepare nanoparticles with chiral nematic phase behaviour close to room temperature and iron/platinum nanoparticles with liquid crystal groups attached.