Preparation and Characterization of Carbon-Doped Mesoporous TiO_2 Elctrorheological Fluid

The carbon-doped TiO2 particles via the route of synthesis of mesoporous TiO2 using dodecylamine (DDA) as a template and carbonization at different temperatures in flowing N2 were prepared. The structures of the carbon-doped TiO2 were investigated by TEM, N2 adsorption- desorption isotherm measurements, XRD and XPS. The TEM photographs of carbon-doped titania show disordered porous particles with size range from 130 to 200nm. The N2 adsorption-desorption isotherm reveals the existence of mesoporosity in these materials with a type Ⅳ isotherm. The XRD patterns indicate that carbon-doped titania particles carbonized both at 673K and at 873K are anatase structures. The XPS analyses suggest that the carbon mainly distributed on the surface layer of the particle. The anhydrous electrorheological (ER) fluid composed of carbon-doped titania powders dis- persed in paraffin liquid shows an intrinsic ER effect. The elctrorheological results show that the carbon-doped TiO2 particles synthesized with DDA/TiO2 mole ratio around 0.046 to 0.092 and carbonized at temperature around 673 K exhibit higher ER activities due to their proper conductivity caused by the carbon on the surface of the particles.