The Effect of Stirring Time on the Characteristics of Carbonated Hydroxyapatite from Pearl Shells (Pinctada maxima)

Carbonated hydroxyapatite (CHAp) is hydroxyapatite (HAp) substituted by carbonate ions that has bioactivity because of their similarities to the natural bone. Pearl shells (Pinctada maxima) have been used as natural ingredients for the synthesis of B type CHAp using precipitation method with different stirring time (0 h, 2 h, and 4 h). The CHAp was characterized by using X-Ray Diffractometer (XRD), Fourier Transform Infrared (FTIR), and Scanning Electron Microscopy (SEM). The XRD results show the characteristics of B type CHAp from the position of the main peak and some diffraction plane, as well as from lattice constants a and c. The position of the main peak and plane (300) is above the position of pure HAp, plane (002) is below the position of pure HAp, and the lattice constants a are smaller than 9.418 and c higher than 6.884. FTIR results showed that the main peak B type CHAp found at wavenumbers 874, 1450 and 1420 cm^-1. According to the FTIR data, it can be concluded that stirring time variations was affecting the intensity of the functional group peaks. The smallest crystal deffect found in 2 h stirring sample based on the calculation of microstrain. SEM results indicated that CHAp morphology was affecting by stirring time. The morphology of CHAp tends to agglomerate for sample with 4 h stirring time.