Influence of the Composition of CexZr1–xO2 Hydrosols on Their Rheological Properties

CexZr1–xO2 hydrosols with different particle compositions (x = 0.8, 0.5, 0.2) were synthesized, and flow curves were measured over a wide range of dispersed‑phase concentrations and dispersion‑medium pH values. It was found that, under the conditions studied, the CexZr1–xO2 hydrosols behave as Newtonian fluids. At the same time, the Einstein equation is obeyed only within a rather narrow range of dispersed‑phase concentrations. Based on the particle density data and their effective volume fraction, the influence of surface layers on the viscosity increase of the hydrosols was evaluated. The effects of both primary and secondary electroviscosity were identified, and their contributions to the measured viscosity of the hydrosols were shown to depend on the dispersed‑phase concentration, the pH of the dispersion medium, and the particle composition.