The Effect of Temperature Synthesis on the Purity and Crystallinity of Hydroxyapatite

Abstract

Hydroxyapatite (HA) is a calcium phosphate compound [Ca10(PO4)6(OH)2] which is non-toxic and has high biocompatibility. HA can be synthesized from natural basic ingredients with high calcium carbonate (CaCO3) content such as chicken eggshells. Here, we reported the synthesis of HA from chicken eggshells by hydrothermal methods. The effects of temperature synthesis of 120 °C and 230 °C on the purity and crystallinity were investigated in order to get information about best synthesis temperature for producing high quality of HA. The structure and crystallinity of HA were determined by XRD and FTIR. Morphology of HA is determined by TEM, while the composition was determined by XRF, respectively. High purity samples of HA with hexagonal structure of P63/m were successfully obtained with synthesis temperature of 120 °C and 230 °C. For HA synthesized in 120°C, the purity was 97.7%, while for HA synthesized in 230 °C, the purity was 97.8%. Two types of impurities, namely Ca(OH)2 and tricalcium phosphate (TCP) ware detected in both samples, It was also obtained the degree of crystallinity of 26.86% and 56.46% for samples synthesized at 120 °C and 230 °C, respectively. HA synthesized with at 230 °C has a higher and better crystallinity.