Preparation of polystyrene/polyaniline composite particles and their electrorheology

Monodisperse polystyrene (PS) seed latex was initially prepared by a dispersion polymerization, and then polyaniline (PANI)-coated PS composite particles were synthesized by diffusion and polymerization of aniline at the interface. Characteristics of the obtained PS/PANI composite particles such as morphology and thermal property were examined using SEM and TGA, respectively. In addition, we employed a rotational rheometer to investigate rheological behaviour of the ER fluids based on both PANI particles and PS/PANI composites. Yield stress and flow response were investigated under electric field strengths showing typical ER behaviours. Further, the Cole-Cole plot and the dielectric spectra gave relaxation times of the ER systems, confirming the correlation of dielectric properties with ER performance.