Thermodynamic Modeling of Hydroxyapatite Crystallization with Biomimetic Precursor Design Considerations

The objective of this paper is to present a hydroxyapatite synthesis biomimetic precursor paradigm and evaluate four precursor systems against its criteria. Thermodynamic modeling was used as a method of evaluation. The system that best fit the paradigm was experimentally validated by synthesizing inorganic powders over a range of reaction conditions and characterizing the reaction products through X-ray diffraction. The Ca(C 2 H 3 O 2 ) 2 −K 3 PO 4 −H 2 O system was found to best fit the paradigm and was effective in synthesizing hydroxyapatite as predicted by the yield diagram. On the basis of the findings of this diagram and its validation, it appears that thermodynamics largely governs the synthesis of hydroxyapatite in all these systems, making these equilibrium diagrams valuable for future research on hydroxyapatite crystallization.