Synthesis of hydroxyapatite powder and its thermal stability

The role of gelatin was examined with the main focus on its induction ability of hydroxyapatite (HA) nucleation in a modified aqueous solution with gelatin. The results show that when the addition of gelatin is in the range of 1wt%similar to3wt%, HA crystal is formed with a perfect crystalline. However, no HA nucleation occurrs when gelatin content reaches 4wt% because of the steric effect. When the dried powder with 4wt% gelatin addition calcined at 900degreesC, the average size of HA is about 40nm which is smaller than those of synthesized particles without gelatin addition. However, this powder is easier to decompose to beta-TCP when sintered at 1000degreesC, and the resultant beta-TCP possesses a significant thermal stability up to 1500degreesC.