Langmuir, Vol.22, No.10, 4504-4511, 2006
Liquid crystal nanoparticles prepared as miniemulsions
Liquid crystal nanoparticles using the low molecular weight liquid crystal E7 are prepared by a miniemulsion approach with a droplet size between 180 and 630 nm. The sizes of liquid crystal droplets prepared in this work are one of the smallest sizes ever reported for liquid crystals, and they are considerably dependent on the type and amount of the surfactant used, as well as on the amount of hexadecane. Furthermore, the behavior of a liquid crystal confined to small droplets is investigated. DSC measurements reveal a large shift in the nematic-isotropic phase transition temperature. Further investigations on liquid crystal droplets are carried out using AFM measurements showing that these particles have an order of the liquid crystal molecules within the droplets. Light scattering measurements yield the temperature dependence of the anisotropy and the temporal stability of the droplets. An effect of the director fluctuations within the droplets on dynamic depolarized scattering was found.