Temperature effect of electrorheological fluids based on polyaniline derived carbonaceous nanotubes

Abstract

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.

Aniline oligomers versus polyaniline

“…The conversion of PANI to nitrogen‐containing carbons after heating to temperatures above 600 °C in an inert atmosphere has recently been illustrated in a number of cases 24, 66, 110–114. The crosslinking of polymer chains to produce phenazine‐like units seems to be preferred over simple degradation.…”

“…The crosslinking of polymer chains to produce phenazine‐like units seems to be preferred over simple degradation. The fact that nitrogen atoms are included in the products is of importance when the resulting materials are used as catalyst supports24, 115 or in supercapacitors112, 116 and electrorheological fluids 28, 29, 113, 114. The morphology of PANI is preserved during the carbonization;66, 110 this allows for the preparation of various carbonaceous nanostructures.…”

Carbonization of aniline oligomers to electrically polarizable particles and their use in electrorheology

“…In recent studies, conducting polymers have been exposed to elevated temperature in inert atmosphere in order to obtain carbonaceous nitrogen-enriched structures [25][26][27][28][29][30]. In some cases, this treatment has positively influenced the ER performance of suspensions based on these materials.…”

Preparation of Smart Fluid from Polymer Coated Pumice Particles

“…Moreover, thermal kinetics and colloidal stability are influenced by change of temperature. The ultimate ER demeanor depends on the balance procured among these factors [20] [21].…”