ELECTRORHEOLOGICAL BEHAVIOR OF THE SUSPENSIONS OF SURFACTANT COATED TiO_2

In the micro--emulsion system of H2O/Span or DBS/n--amyl alcohol/xylene, the particles of TiO2 coated by surfactant are obtained. The Electrorheological (ER) behavior of the suspension made of TiO2 coated by surfactant in dimethylsilicone oil with a 31% volume fraction is investigated. The result showed that covering surfactant could increase the ER activity of TiO2. In the electrical field of 3kV/mm, the shear stress is about 1.4kPa, while the current density is only 25μA/cm2. This method has a better effect than that of adding surfactant in silicone oil simply. The content of coated surfactant had a strong influence on ER behavior. At the same time, because R = [H2O]/[Surfactant] could control particles' granularity and content of coated surfactant in the method of W/O micro--emulsion technique, the sedimentation could be controlled and modified by surfactant.