Formation of biomimetic apatite on calcium phosphate foam ceramics in standard and carbonate-free model solutions

Abstract

The biomimetic apatite was formed in the carbonate-free Simulated Body Fluid model solutions of standard composition on calcium phosphate foam ceramics, consisting of α/β-tricalcium phosphate and β-calcium pyrophosphate. The apatite phase composition was determined by the composition of Simulated Body Fluid solution used during soaking. The equilibrium shift in the model solution during the interaction of calcium phosphate foam ceramics with ions of the solution leads to the apatite precipitation in the aggregated particles form. The excess content of H+ ions in carbonate-free Simulated Body Fluid leads to pH sharp fluctuations and the inclusion of hydrated СaClH2PO4 impurity into apatite spherulites. An increase in the soaking time in Simulated Body Fluid model solutions to 21-28 days leads to coarsening of apatite spherulites to 5-6 µm. The foam ceramics surface morphology after soaking changes insignificantly with a slight decrease in the through porosity by 1-3% and two times increase in static strength due to the healing of microdefects in the foam ceramics structure.

Keywords

• calcium phosphate foam ceramics
• tricalcium phosphate
• sbf (simulated body fluid)
• biomimetic apatite
• spherulites