Hydroxyapatite nanocrystals synthesized from calcium rich bio-wastes

[Display omitted] •HA was synthesized using different calcium rich biowastes and wet chemical precipitation.•HA nanocrystals were characterized using TEM, XRD, DLS, zeta potential and FTIR analysis.•Same characteristic were obtained for the HA synthesized using different feedstocks using the same production method. Hydroxyapatite nanocrystals were synthesized by wet chemical precipitation using bio-waste shells of mollusk (clam and mussel) and egg as feedstock materials. The powdered shells were calcined, dissolved in water, and the resulting product was reacted with phosphoric acid. X-ray diffraction analysis identified pure phase of hydroxyapatite for the three different raw materials. Transmission electron microscopy observations of hydroxyapatite indicated that rod-like crystals were produced in nanometric scale, which showed pH-dependent surface charges using zeta potential analysis. Overall, this study proved that calcium-rich bio-wastes are valuable materials to be used as feedstock for production of high purity and economically feasible hydroxyapatite nanocrystals for biomedical and technological applications.