Novel fabrication of polyaniline particles wrapped by exfoliated clay sheets and their electrorheology

Taking into account of unique merits of conducting polymer/inorganic nanocomposites which play a positive effect in enhancing electrorheological (ER) performances, we adopted exfoliated clay sheet as a stabilizer to fabricate novel nano-scaled polyaniline (PANI) granules (PANI/clay) via pickering inverse emulsion polymerization in this study. Successfully synthesized PANI nano-spheres which were initialized by oil-soluble benzoyl peroxide possessed polydispersed size distribution. These armed PANI nanoparticles, of which the surface is compactly wrapped by clay sheets, are observed, as confirmed by SEM and TEM images. Some nano-scaled particles even possess irregular shape with sharp angle because clay plates are difficult to be bended to follow the spherical trace due to the extremely small size of PANI granules. The extent of exfoliation of Clay sheets covered on the surface of PANI particles were characterized by XRD pattern which did not indicate any obvious sharp peak, demonstrating the nearly completely exfoliated clay layers. TGA spectra also gave some additional information on thermal stability and mass composition. At last, an ER fluid was prepared by dispersing PANI/clay nanoparticles in silicone oil and the ER performances were investigated via a rotational test.