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

Abstract

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 À1 . 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.

Titanium Dioxide Nanoparticles Modified with Disulfonic Acid Functionalized Imidazolium Ionic Liquids for Use as Electrorheological Materials

“…Properties of both the dispersed phase and the continuous liquid materials are key factors affecting their properties in the research into ER components. − Researchers have paid more attention to developing dispersed phase materials with high ER properties because of the greater diversity and designability of the dispersed phase materials. The types of the dispersed phase materials are generally divided into inorganic materials, − organic materials, , and composite materials. , Among a variety of inorganic materials, titanium dioxide (TiO 2 ), as a kind of transition-state oxide with relatively high dielectric properties and polarizability, is a promising high-performance ER material. − However, the paucity of active groups on the surface of pure TiO 2 nanoparticles and their low conductivity limit the polarizability of the particles, which causes pure TiO 2 to have poor ER properties. , When the ER fluids are composed of TiO 2 and a small amount of water, the system will exert a better ER effect. This is because water acts as a polar molecule to provide permanent dipoles from forming on the surface of the particles.…”

Controllable Microemulsion Synthesis of Hybrid TiO2–SiO2 Hollow Spheres and Au-Doped Hollow Spheres with Enhanced Photocatalytic Activity

“…46 The absorption peaks at 1023 and 900 cm ), which suggests that the calcined sample is composed of a TiO 2 −SiO 2 molecular hybrid framework. 47 In addition, XPS analysis (Figure 5) was involved to evaluate the compositions of TS-HSs before and after calcination. Before calcination, the binding energies are located at 101.…”

“…These results indicate that the TESPT organosilica source and the TDAA titanium source are co-condensed, forming a hybrid TiO 2 –SiO 2 framework. After annealing, the characteristic peaks at 2922, 2853, and 1245 cm –1 disappear, leaving only the peaks with Si–O–Si (1090 cm –1 ), Ti–O–Si (936 cm –1 ), and Ti–O–Ti (640 cm –1 ), which suggests that the calcined sample is composed of a TiO 2 –SiO 2 molecular hybrid framework …”

Inorganic Reinforced Poly(ionic liquid) Microcapsules: Confined Cooling‐Assisted Phase Separation Self‐Assembly and Enhanced Electroresponsive Properties

“…It is observed that no sedimentation after ageing for 240 h, while pure PIL microbead suspension shows 60% sedimentation. This enhanced suspension stability can be attributed to the hollow structure of SiO x -PIL microcapsules, which not only decreases the apparent density, [36][37][38][39] but also provides better affinity towards the silicone oil by SiO x . Figure 3b presents the electric field-induced shear stress (Δ𝜏) of ER suspensions of SiO x -PIL microcapsules under electric fields.…”