Paper Title
The Influence of pH on Phase and Element Composition of Hydroxyapatite Synthesized by Wet Chemical Precipitation Method

Hydroxyapatite (HA) was synthesized by wet chemical precipitation method with different pH values (pH 7, 8, 8.5, 9, 9.5, 10, 11) and calcined at 1200 °C to investigate their influence on the HA phase composition, element composition and morphology. X-Ray Diffraction (XRD), Inductively Coupled Plasma (ICP), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM) were performed to the characterized crystalline structure, chemical composition, chemical bonding, morphology and particle size of HA powders, respectively. Results have shown that pH value played a significant role parameter in altering the phase composition, element composition. The result decreased pH values from 11 to 7, resulting in shown HA and CaO at pH 11 to 9, and HA and TCP at pH 8 to 7, while pH 8.5 provides a single phase with stoichiometry HA (CA/P ratio 1.674). Keywords - Hydroxyapatite, pH, Wet Chemical Process, Ca/P Ratio