Anisotropic α‐Fe 2 O 3 @TiO 2 Core–Shell Nanoparticles and Their Smart Electrorheological Response

Abstract

α-Fe2O3@TiO2 core–shell nanoparticles were prepared through a combination of reflux and hydrolysis methods. Firstly, a spindle-like and monodispersed α-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 α-Fe2O3 core with a uniform thickness by means of a controlled hydrolysis method. The morphology, structure, and electrorheological (ER) activity of α-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 α-Fe2O3@TiO2 and hollow TiO2 ER suspension compared with that of a pure α-Fe2O3 ER suspension.