Investigation of Electrorheological Fluid Performance with Size-Controlled TiO₂ Nanoparticles

Electrorheological (ER) fluids, known for their tunable viscosity under electric fields, are of significant interest for various engineering applications, including shock absorbers and haptic feedback systems. This study investigates the impact of size-controlled TiO₂ nanoparticles on the performance of ER fluids. TiO₂ nanoparticles with diameters ranging from 143 to 370 nm were synthesized using a double-surfactant assembly-directed method. Rheological measurements revealed that ER fluids containing smaller TiO₂ particles exhibited higher shear stress under an electric field. Additionally, optical microscopy confirmed that smaller spheres formed denser fibrillar structures, thereby enhancing ER fluid performance. However, dielectric property analysis showed that smaller particles had lower polarizability and slower relaxation. Sedimentation tests indicated that ER fluids with smaller TiO₂ particles had improved dispersion stability, further enhancing the performance of the ER fluid. These findings provide valuable insights into optimizing ER fluid performance by controlling TiO₂ particle size.