Preparation and Electrorheological Property of NH₂-MIL125@SiO₂ Core–Shell Nanoparticle

In this paper, NH2-MIL125@SiO2, a composite with outstanding electrorheological (ER) properties, was synthesized by using solvothermal and Stöber hydrolysis methods. A polar functional group, NH2, was introduced to improve polarization ability by taking advantage of MIL125’s numerous surfacial active sites and ease of pore surface modification. SiO2, which regulates electrical conductivity and improves dielectric properties, was then capped on the surface to form a core–shell structure, i.e., NH2-MIL125@SiO2. In the discussion part, SEM, TEM, and elemental mapping were used to analyze the samples’ surface topography, internal structure, and surface elements. XRD, FT-IR, and XPS were used for investigating the crystal structure, elements, and functional groups; BET was used to assess the specific surface area and pore size variation. Dielectric measurements were conducted to investigate the polarization behavior. At last, we used the HAAKE rotating rheometer to analyze and compare the ER characteristics of the NH2-MIL125@SiO2 series ERFs. Its ER efficiency exhibits as high as 688 at an electric field strength of 3 kV/mm. The results demonstrated that the NH2-MIL125@SiO2 nanocomposite particles exhibited superior dielectric properties and outstanding ER characteristics compared to single MIL125.