Abstract: 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 N_2 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 dispersed 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.

Key words: TiO₂ particles, anhydrous electrorheological (ER) fluids, carbon-doped