Hydroxyapatite coatings obtained by the thermal activation of polymeric sols

Hydroxyapatite (HAP) coatings have been developed to exploit the bioactive properties of this material which are related to its specific composition and crystalline structure. Carbonated HAP films were obtained on (100)/Silicon substrates by the thermal activation of a polymeric sol of selected stoichiometry utilising an aerosol–gel reactor. This technique provides several advantages in the control of the morphology and thickness of the coatings. Sintering temperatures reaching 1000°C were applied to enhance the crystallinity and purity of the films. The samples have been characterised by the use of FTIR, XRD and SEM. Measurements of the stoichiometry, crystallinity, microstructure and morphology of the coatings prove the formation of HAP films appropriate for several bioactive applications.