Synthesis and characterization of eggshell-derived hydroxyapatite via emulsion method.

The disposal of biowaste such as animal bones and shells has been a growing concern. To tackle sustainability concerns, this study explores the utilization of eggshells as calcium precursor in the synthesis of hydroxyapatite (HA). Eggshells were subjected to calcination at 1000 °C for 3 hours and 6 hours to obtain calcium oxide, which was then used to synthesize HA through an emulsion method. The FTIR spectra of the synthesized HA closely resembling the characteristic peaks of HA reported in literature. The resulting HA from eggshell-derived calcium oxide displayed flake- like structures, while its sintered counterparts exhibited a porous structure, which are potentially advantageous for bone attachment and regeneration. The sintered HA pellet using 6-hour eggshell-derived calcium oxide showed a higher Ca/P ratio (1.13) and relative density (71.8%), compared to 3-hour calcination process. Despite deviating significantly from the stoichiometric Ca/P ratio of 1.67, the EDS spectra closely resembled literature values. Further research could explore the practical implementations of eggshell-derived HA in various biomedical and biomaterials development and waste management. [ABSTRACT FROM AUTHOR]