Produits de solubilité apparents des hydroxyapatites calcique, cadmiée et strontique
Written by sctunisie no commentsThe apparent solubility products of calcium, cadmium and strontium hydroxyapatites were determined in dilute solutions of phosphoric acid at 25, 37, 50 and 70°C. The results show that the solubility of the strontium hydroxyapatite is greater than that of the calcium hydroxyapatate which is itself greater than the solubility of the cadmium hydroxyapatite. These apatites show retrograde solubilities. In the case of calcium apatite the infrared spectroscopy and the X ray diffraction patterns don't show any modification of the solid apatitic phase after equilibrium, when in the case of strontium hydroxyapatite the solid phase in equilibrium with the solution at 37°C is a mixture of SrHPO4 and Sr3(PO4)2. The cadmium hydroxyapatite changes also from 50°C to give partially CdHPO4. The appearance of these new phases is assigned to secondary reactions and to the surface effect of the solid particles.
S. Ben Abdelkader, I. Khattech, M. Jemal
Pages 1111-1123
