Effect of CAP and PH in the wet-synthesis reaction on the formation of different calcium phosphate phases

Abstract EN

Recently, there has been a growing new paradigm to use synthetic calcium phosphate biomaterials as bone substitutes in orthopedics applications.

Their structure and composition are close to the human bone, and thus conferring them a good biocompatibility and osteoconductivity.

Wet process is normally used for the synthesis of Hydroxyapatite (HA) and beta-tricalcium phosphate (β-TCP).

However, the wet process was reported to be less reproducible for fabrication of pure apatitic phases in comparison to other synthesis processes.

In this study, it is hypothesized that a specific apatitic phase that is normally obtained from stoichiometric reaction can be synthesized by using non-stoichiometric based reactants in a reproducible way by controlling the pH value during the synthesis process.

A factorial design with two factors and three repeats was implemented to examine the hypothesis [A: Ca/P (1.5, 1.55, 1.667) and B: pH (7.5, 9.5)].

All precipitated powders were dried and aged overnight and then sintered for 2 hours at 800 °C.

The powders were analyzed for phase, group and morphological analysis by X-Ray Diffraction (XRD), FTIR, and ESM/TEM, respectively.

The results have revealed a better understanding of how to synthesize pure calcium phosphates phases for the repair of bone defects using the cost-effective wet chemical process.

Small variation in the reactant molar ratio can significantly change the precipitated phases.

Controlling the reaction pH can governor effectively the precipitation of a specific phase despite of the small variation in the molar ratio