Fabrication of semiconducting polyaniline/nano-silica nanocomposite particles and their enhanced electrorheological and dielectric characteristics

As a new electroresponsive electrorheological (ER) polymer/inorganic nanocomposite material, polyaniline (PANI)/nano-silica nanocomposite was synthesized via an in situ chemical oxidative polymerization method. Morphology and thermal property of the synthesized nanocomposite were examined by scanning electron microscope (SEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). In comparison with pure PANI, the PANI/nano-silica nanocomposite based ER fluid dispersed in silicone oil exhibited improved ER performance with a higher yield stress. The increment of storage modulus with electric field strength was also observed via a vertical oscillation rheometer. These ER characteristics were found to be well correlated with dielectric properties of the ER fluids measured using an LCR meter.