Titanium oxide-coated titanium-loaded metal organic framework (MOF-Ti) nanoparticles show improved electrorheological performance

Abstract

Uniform small-sized MOF-Ti nanoparticles were prepared by a one-step hydrothermal method, and then a 5–10 nm TiO₂ shell was coated onto them by using the sol–gel method, and MOF-Ti/TiO₂ with a specific surface area of 50.2 m² g⁻¹ was successfully prepared. The nanoparticles were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), nitrogen adsorption–desorption isotherms (BET), and X-ray photoelectron spectroscopy (XPS). The above-analyses have elaborated the experimental study of their morphology, elements, and energy of organic functional groups. At the same time, through the use of a high-voltage rotary rheometer to test their rheological properties, the analysis of shear stress, ER efficiency, shear viscosity, etc. was performed and their dielectric constant and dielectric loss were studied by using a broadband dielectric spectrometer. Finally, we found that MOF-Ti/TiO₂ is a new core–shell nanocomposite particle with a small particle size and good electrorheological properties.