Influence of particle size and morphology of chemically modified hydroxyapatite by sol-gel method

Abstract

Hydroxyapatite (HAP) is an inorganic compound with the chemical formula of Ca10(PO4)6(OH)2. It has been recognized as a substitute material for bone and teeth in orthopedics and dentistry due to their chemical and biological similarity to human hard tissue. Synthetic nano-sized HAP particles exhibit favorable biocompatibility and bioactivity and in order to better match the composition to natural HAP there is a great interest in producing a range of chemically modified hydroxyapatite powders. In this study, three different powders have been synthesized via an ethanol-based sol-gel method. Calcium nitrate tetra hydrate and P2O5 were employed as calcium and phosphorus precursors respectively. An aqueous solution of Ammonium hydroxide was added as dispersing agents to the reaction mixture. Separately, sodium hydroxide was added as a dispersing agent and the pH of the solution was modified as 10.5. Subsequent powder calcinations have been carried out within the temperature range of 900 °C and the resultant powders were characterized by AAS, Powder-XRD, FT-IR and SEM analysis.