The behavior of the hydroxyl groups in polycrystalline porous hydroxyapatite

The activation energy of charge carriers and carrier density in porous polycrystalline hydroxylapatite have been determined by electrophysic measurings in temperature range 15-110'C. As charge carriers in hydroxylapatite is ions, the obtained values were checked by means of IR-spectroscopy using to IR-spectra sections corresponded to oscillations of bond, dissociating to form the conduction ions. It was turned out that mostly the conduction porous polycrystalline patterns of hydroxylapatite has been formed by hydroxylions in the investigated range of the temperature. It is also defined by series of values of activation energy changing from the dissociation energy of water molecule to the split-out-energy of hydroxyl groups of hydroxylapatite molecule. It was observed that values of activation energy and carrier density have been correlated with area of internal surface of material and with amount of hydroxyl groups, the IR-spectroscopy is ascribing to not formula hydroxyl groups of hydroxylapatite. On the basis of these results one is postulated that apatite can exist either in the form of oxy-hydroxylapatite or else in the form of hydroxylapatite, but behavior of share of hydroxylgroups of material is coincide with behavior of hydroxyl groups forming an adsorption lauer of water on the surface of porous polycrystalline hydroxylapatite.