Temperature effect of electrorheological fluids based on polyaniline derived carbonaceous nanotubes

Nitrogen-enriched carbonaceous nanotubes (N-CTs) were prepared by the carbonization of polyaniline (PANI) nanotubes in vacuum and were demonstrated to possess good electrorheological (ER) performance. In this paper, the temperature dependence of the ER properties of the suspension composed of N-CTs in silicone oil was systematically investigated by steady shear viscosity and dynamic viscoelastic measurements. These showed that under electric fields the N-CT suspension showed good temperature stability of its ER properties though its zero-field viscosity decreased with elevated temperatures. Meanwhile, the flow curve of shear stress versus shear rate also maintained a stable level and the critical shear rate shifted towards high values as the operating temperature increased. The dynamic viscoelastic measurement showed that the storage modulus slightly increased with increasing operating temperature, also confirming the good temperature stability of the ER properties of the N-CT suspension. The dielectric spectra of the N-CT suspension and the dielectric parameters calculated by the Cole-Cole equation could explain the temperature dependence of the ER properties of the N-CT suspension.