Electrorheological properties of titanate nanotube suspensions

Titanate nanotubes were synthesized by hydrothermal reaction of titania nanoparticles in alkali solution and the electrorheological (ER) properties of titanate nanotubes/silicone oil suspension were investigated. Compared to the titania nanoparticle suspension, the nanotube suspension showed better ER effect. The effects of material structure and external temperature on ER properties were especially investigated. It was found that the alkali-ions, intercalated in the interlayer of nanotube, were important to the ER activity of titanate nanotube. Removal of alkali-ions by acid-treatment did not destroy the nanotube morphology but weakened ER effect. According to dielectric analysis, the change of dielectric properties after removing alkali-ions may be the reason of the decrease of ER properties of nanotube. In addition, the ER effect of titanate nanotube suspension increased with temperature, which was in accordance with the improving particle polarization by dielectric measurement. Temperature effect became poor after removal of alkali-ions. (C) 2008 Elsevier B.V. All rights reserved.