Sol-gel preparation of graphite/TiO2 composite particles and their electrorheological effect

Graphite/TiO2 composite particles were obtained by sol-gel technique in this paper. The structure and characteristic of the composite particles are analyzed by XRD, SEM and TG-DTA. The electrorheological properties of the ER fluid containing the particles were measured by a Couette-type rheometer under shear rates of 1similar to136 s(-1) and AC electric fields of 0similar to3 kV/mm. The experimental results show that the leaking current density of the ER fluid is higher than that of pure titanium dioxide particles dispersed in damping oil. The shear yield stress of the ER fluid increases with increasing electric field and exhibits a typical Bingham flow behavior. The suspension demonstrates an excellent ER performance (tau/tau(0)=1200) compared with conventional ER fluids (tau/tau(0) less than or equal to500). The sedimentation of the ER fluid is improved obviously due to the coating effect of the particles.