Composition of calcium deficient Na-containing carbonate hydroxyapatite modified with Cu(II) and Zn(II) ions

In this paper, the compositions of calcium deficient Na-containing carbonate hydroxyapatite (NaCHA) modified with Cu(II) and Zn(II) ions was studied by means of ICP, XPS and FTIR. The obtained results indicate that NaCHA is more soluble in ion-exchange medium, resulting in the incorporation of more metal ions. The ICP and XPS analyses indicate that the enrichment of Zn2+ is more than that of Cu2+ on the surface. Moreover, Cu2+ ions have substituted for Ca2+ and Na+ ions and also enter into the vacancy and/or the hexagonal channels in NaCHA lattice. The above results indicate that NaCHA modified with Cu2+ and Zn2+ displays a predominant dissolution-precipitation or coprecipitation mechanism and at the same time, adsorption and diffusion mechanism maybe also exist.