WATER BASED SOL-GEL SYNTHESIS AND CHARACTERIZATION OF HYDROXYAPATITE

Abstract

Sol-gel technology for Hydroxyapatite (HAp) synthesis has been developed more than a decade ago. The existing sol-gel HAp synthetic methods which use alkoxide - based precursors require solvent based diluting media, a moisture — controlled atmosphere, prolonged synthesis time generally greater than 24 hours, and a heat treatment at temperature greater than 500°C over a time period of several hours. Those limit practical applications of HAp. Therefore, in this work, HAp ceramics were synthesized using water based sol — gel route with Calcium nitrate and Triethyl phosphite as calcium and phosphorous precursors, respectively. It was `:,, expected that the water based sol — gel process can be a feasible materials technology for biomedical applications. Water was the only medium used as diluting medium for HAp sol preparation. The sol only became gel after the removal of solvent at 80°C. XRD showed that the apatitic structure first appeared at a temperature as low as 400°C. The XRD analysis was used to examine the phase transformation of HAp at different temperature. The functional group change of HAp at different temperature was observed by FTIR spectroscopy. The morphological feature of the raw and sintered samples was examined. The synthesized powder was characterized through ;FTIR, XRD, Thermal analysis and SEM analysis.