Nucleation of hydroxyapatite layer on wollastonite material surface: FTIR studies

Wollastonite belongs to a group of calcium silicates showing bioactivity. In the presented work Fourier transform infrared spectroscopy in the attenuated total reflection mode (FTIR-ATR) and scanning electron microscopy with energy dispersive spectrometry (SEM–EDS) methods were used for investigation of the hydroxyapatite nucleation on different types of bioactive wollastonite ceramics. Wollastonite (CaSiO3) has been obtained by controlled pyrolysis of organosilicon precursors together with active inorganic fillers. From powders prepared in this way, two different types of dense ceramics bars were sintered. One type was sintered from the wollastonite powder with carbon addition (Wc) and another one from the powder after oxidation process (W). The obtained ceramics has been immersed in simulated body fluid (SBF) to investigate its bioactive features. Hydroxyapatite layer nucleation on samples was compared. Bioactivity of the samples as a function of incubation time has been examined by FTIR-ATR and scanning SEM–EDS methods. Differences in nucleation of hydroxyapatite can be observed among the two different types of the samples.