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 Matijevic [1].

Keywords

• zirconia
• viscoelasticity
• critical parameters