Peroxide-doped apatites: Preparation and effect of synthesis parameters

• Peroxide doped apatites were prepared.
• The impact of synthesis parameters on physico-chemical features were explored.
• H2O2/H2O medium is appropriate for obtaining nanocrystalline peroxide apatites.
• The presence of peroxide ions was evidenced and quantified.
• This led to modifications in physico-chemical characteristics.

This contribution focused on the preparation of peroxide-doped calcium phosphate apatites — in view of potential uses as bioactive bioceramics with antimicrobial functions, and on their main physico-chemical characteristics. Two synthesis routes were investigated. First, the hydrolysis of β-TCP in the presence of H2O2 was followed. However, only elevated concentrations in H2O2 in the medium or temperatures around 150 °C allowed us to reach the complete β-TCP-to-apatite hydrolysis process, and the obtained samples exhibited a high crystallinity state with no non-apatitic chemical environments. The second protocol tested consisted in the direct apatite precipitation in the presence of H2O2 in the medium (at room temperature). This protocol led to single-phased nanocrystalline apatites, and our data indicate that part of the apatitic OH− ions were substituted by oxygenated species, and typically by peroxide ions (quantified). Physico-chemical modifications in the form of an improvement in crystallinity state, an increase in unit cell volume, and the presence of additional Raman bands were noticed and discussed.

Figure optionsDownload as PowerPoint slide