Synthesis Route and Characterization of Hydroxyapatite Powder Prepared from Waste Egg Shells

Abstract

A novel route is reported to prepare Hydroxyapatite powder (HAp) from egg shells. Eggshells were used as calcium precursor containing 94-97 % CaCO₃. HAp was synthesized by reacting calcined egg shell powder with reagent grade phosphoric acid at room temperature by precipitation method followed by sintering at 900oC to get crystalline powder. Calcium and phosphorous were determined by Gravimetric and Spectrophotometric method respectively. The Ca/P molar ratio was found to be 1.63. Phase transformation was studied using powder XRD results showing characteristics diffraction peak for HAp and FTIR spectra show the characteristic peaks for phosphate and hydroxyl groups. Thermal analysis (DSC-TGA) was also carried out to investigate the thermal behavior of hydroxyapatite (HAp) powder