XPS study of apatite-based coatings prepared by sol-gel technique

Biocompatible layers of hydroxyapatite and fluorhydroxyapatite were grown on Ti substrates by means of dip-coating into sol-gel. In order to improve the adhesion of apatite-based coatings, the substrates were a priori covered with calcium titanate. Therefore, the hydroxyapatite, fluorhydroxyapatite and CaTiO3 coatings were produced and analysed. The chemical composition of the coatings (CaTiO3, CaTiO3 + hydroxyapatite, and CaTiO3 + fluorhydroxyapatite) was studied by using X-ray photoelectron spectroscopy (XPS). The data of quantitative XPS analysis displayed the different features (cleanness, homogeneity, etc.) of CaTiO3, hydroxyapatite, and fluorhydroxyapatite films after the growth and after the treatment in vitro.