Effect of calcination temperature on the electrokinetic properties of colloidal zirconia

doi:10.1016/S0927-7757(96)03744-2

Colloids and Surfaces A: Physicochemical and Engineering Aspects

Volume 119, Issues 2–3, 16 December 1996, Pages 205-213

https://doi.org/10.1016/S0927-7757(96)03744-2 Get rights and content

Abstract

The zeta potentials of three different zirconia samples which had been calcined at 450, 650 and 850°C, in aqueous KNO₃ solutions at 25°C were measured using the technique of microelectrophoresis. The effects of pH and electrolyte concentration on the electrokinetic properties of the zirconia colloids were investigated. An Atomic Force Microscope (AFM) was used to measure the forces of interaction, as a function of the distance of separation, for a colloidal sphere of zirconia (calcined at 850°C) with a polished, flat, zirconia plate. These measurements were performed across a range of pH values at three different electrolyte concentrations. The experimental data were seen to fall between the best fits to the DLVO theory at the limits of constant surface charge and constant surface potential although, typically, they tended towards the higher constant charge limit. Potentials obtained from these best fits to the AFM data were compared with the zeta potentials derived from the electrophoresis experiments. The force-distance data obtained with the AFM at the isoelectric point were seen to be well fitted with an attractive van der Waals interaction curve having a Hamaker constant of 6 × 10⁻²⁰ J.

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Another application is the analysis of surface forces per se. Some of the most fundamental questions in colloid and surface science can be addressed directly with the AFM: What are the interactions between particles in a liquid? How can a dispersion be stabilized? How do surfaces in general and particles in particular adhere to each other? Particles and surfaces interactions have major implications for friction and lubrication. Force measurements on single molecules involving the rupture of single chemical bonds and the stretching of polymer chains have almost become routine. The structure and properties of confined liquids can be addressed since force measurements provide information on the energy of a confined liquid film.
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Effect of calcination temperature on the electrokinetic properties of colloidal zirconia

Abstract

Biomaterials

Croat. Chem. Acta

Mater. Chem. Phys.

Mater. Chem. Phys.

J. Electroanal. Chem.

J. Colloid Interface Sci.

J. Colloid Interface Sci.

Colloids Surfaces

Clays Clay Minerals

Acta Physiochem.

The Environmental Chemistry of Aluminium

An Introduction to Zeolite Molecular Sieves

Principles of Catalyst Development