The wettability, size effect and electrorheological activity of modified titanium oxide nanoparticles

Wettability of particles plays an important role on its electrorheological effect, especially for the nanoparticles. Modified titanium oxide nanoparticles are fabricated via a combination of modified hydrolysis and solution composite methods. The sodium dodecylbenzenesulfonate (SDBS) is used as size-control and surface-modified agent. The X-ray diffraction analyses, fourier transform infrared spectrometry, transmitting electron microscopy are used to determine the structure of the nanoparticles. The influence of wettability on the magnitude of the ER phenomenon was examined. The results show that the size of modified titanium oxide particles is tightly associating with the wettability and the wettability of modified titanium oxide nanoparticles is improved enormously than that of the bare micro titanium oxide. An excellent electrorheological effect is found with the suspension of modified titanium oxide nanoparticles dispersed in silicone oil. The size effect of nanoparticles, the super-oleophilicity caused by the introduction of SDBS and the proper dielectric properties are the intrinsic reasons for the enhancement of electrorheological effect. (c) 2006 Elsevier B.V. All rights reserved.