Characterization of the linear viscoelastic region in suspensions of zirconium oxide: Cohesive energy obtained from the critical parameters

Abstract

The linear viscoelastic regions (L.V.R.) of suspensions of zirconium oxide particles were determined and characterized through the so-called "critical parameters". These are the values of shear-stress and strain at the crossover between the linear and the non-linear viscoelastic responses. From these magnitudes, the cohesive energy between the particles is calculated as a function of volume fraction of solids and at different electrolyte concentrations. The oscillatory measurements were carried out using a constant-stress rheometer at a fixed frequency of 1 Hz and increasing shear-stress. The suspensions cover a volume fraction range between 3% - 25% with electrolyte (sodium chloride) concentrations of 10-1 M, 10-2 M, 10-3 M and 10-5 M. Two different kinds of ZrO2 particles were used: commercially obtained -with no defined geometry- and spheres synthesized by us following the method described by Aiken, Hsu and Matijevici [1]. © Appl. Rheol. 14 (2004).