Anisotropic [alpha]-Fe2O3@TiO2 Core-Shell Nanoparticles and Their Smart Electrorheological Response

[alpha]-Fe2O3@TiO2 core-shell nanoparticles were prepared through a combination of reflux and hydrolysis methods. Firstly, a spindle-like and monodispersed [alpha]-Fe2O3 nanorod core was fabricated by using a reflux method. In the second step, an amorphous TiO2 shell was coated onto the surface of the nonspherical [alpha]-Fe2O3 core with a uniform thickness by means of a controlled hydrolysis method. The morphology, structure, and electrorheological (ER) activity of [alpha]-Fe2O3@TiO2 core-shell nanoparticles were determined by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), magnetic testing, and by using a rotational rheometer. The resulting nonspherical core-shell nanoparticles possess the advantages of uniform sizes, weak magnetism, and smart electrorheological behavior. An enhanced ER effect is found with the [alpha]-Fe2O3@TiO2 and hollow TiO2 ER suspension compared with that of a pure [alpha]-Fe2O3 ER suspension.