Synthesis of hydroxyapatite based on coral Banyuwangi using sol-gel method: observe the effect of calcination temperature on its phase and crystallinity

Abstract

A research on the effect of the calcination temperature on the hydroxyapatite phase and its crystallinity formed has been done. The synthesis method uses sol-gel, for the reason that it can precisely control the composition, the process using low temperature, can produce high purity and homogeneity.The material used is coral from Banyuwangi, East Java. To optimize the forming process, the coral powder was made of 54.84 nm using mechanical high energy milling (HEM-3D) method. Sol-gel methods include hydrolysis, condensation, aging, and drying. The calcination process was then carried out with temperature variations of 450°C, 550°C, 650°C, 700°C, 750°C, 80 °C, 850°C and 900°C. The result of XRD observation shows that the temperature of 550°C gives the optimum hydroxyapatite phase which is 90.8%. In addition, at temperatures below 550°C formed Tricalcium phosphate (TCP), whereas above the temperature formed tetrakalsium phosphate (TTCP). The lower the calcination temperature, the larger the TCP. Conversely, the greater the calcination temperature the greater the TTCP phase. Both phases, both TCP and TTCP are unstable calcium phosphate compounds. The observation results also show that the increase of calcination temperature can increase the degree of crystallinity. The degree of crystallinity of the sample at 900°C is 77.28%, twice the degree of crystallinity of 450°C. In addition, an increase in calcination temperature increases the size of the crystal as well, although the increase is not consistent as the degree of crystallinityIn this study a magnetization reversal dynamics observed in the heat assisted.