Preparation and Electrorheological Properties of Peanut‐Like Hollow Core–Shell Structure TiO2@SiO2 Nanoparticles

Although titanium oxide has a high dielectric constant, ordinary titanium oxides are not a good electrorheological (ER) fluid material. Herein, hollow peanut‐like titanium oxide spheres are synthesized by hydrothermal method, and then coated with silicon oxide to form core–shell hollow TiO 2 @SiO 2 spheres. The structure is characterized by different methods, and the TiO 2 @SiO 2 composite particles are dispersed in silicone oil to prepare an ER suspension. The ER effect of 10% TiO 2 @SiO 2 ‐based ER fluid under different electric field strengths is tested, and its performance is analyzed. The results show that the coated particles significantly enhance the current meter performance. The shear stress value exceeds 200 Pa at an electric field strength of 3.0 kV mm −1 . The shear stress, shear viscosity, switching effect, and dielectric behavior of the base ER fluid are studied. And, the cause of this strong ER effect is studied. In the end, it is found that TiO 2 @SiO 2 peanut‐shaped composite core–shell particles have a good ER effect and which is a kind of ER candidate material with simple preparation and development prospect.