Electrooptical and Dielectric Properties of Alkylthiol-Capped Gold Nanoparticle-Ferroelectric Liquid Crystal Nanocomposites: Influence of Chain Length and Tethered Liquid Crystal Functional Groups

The influence of gold nanoparticles dispersed in ferroelectric liquid crystals (FLCs) on the properties of the resulting nanocolloids has been investigated by thermoanalytical, electrooptical and dielectric methods. All gold nanoparticles were protected by thiolate capping layers either connected via alkyl groups of different chain length or via flexible spacers bridged to liquid crystalline p-cyano-biphenyl end groups. The colloidal stability of the gold nanocomposites with capping layers consisting of nonyl or octadecylthiolate groups is drastically reduced compared to the stability of those with p-cyano-biphenyl end groups. The present work describes the influence of the kind of capping layers around the gold nanoparticles and the effect of the amount of gold nanoparticles dispersed in such liquid crystal colloids on their electrooptical and dielectric parameters.