Rheological behavior of aqueous suspensions of hydroxyapatite (HAP).

The aim of this study is to characterize the influence of organic dispersants on the stability of hydroxyapatite (HAP) dispersions, using viscosity measurements, electrokinetic sonic amplitude (ESA) measurements and adsorption isotherms. Colloidal stability of aqueous suspensions of HAP as a function of solids loading and of the type and concentration of deflocculant has been studied. The interaction between particles and dispersant molecules was characterized. Adsorption measurements of the amount of dispersants on the particles surface, viscosity and electrophoretic measurements as a function of the dispersant concentration are correlated. Suspension parameters have been adjusted in order to obtain a high solids loading slurry with a plastic viscosity which will allow its use in colloidal processing.