Carbonated Hydroxyapatite Derived from Cerastoderma edule, Paphia undulata, and Meretrix meretrix Shells

Carbonated hydroxyapatite (CHAp) derived from three different shells, Cerastoderma edule, Paphia undulata, and Meretrix meretrix shells, have been synthesized by precipitation method. Calcium oxide from extracting shells, diammonium hydrogen phosphate, and ammonium bicarbonate was used to synthesis as the starting precursors. The CHAp materials were analyzed by Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared (FT-IR), and X-Ray Diffractometer (XRD). EDS analysis showed that the Ca/P ratio of CHAp powders were around 1.75-1.77 (bigger than the Ca/P ratio of HAp) and carbonate content of the powder CHAp was 3.10-4.05wt%. XRD data has produced diffraction patterns from the three different shells similar to the apatite structure. The position of the main peak (2 theta) diffraction patterns detected at 31.99 degrees, 32.23 degrees, and 31.95 degrees. The lattice parameter of a-axis and c-axis were obtained around 9.37 angstrom. and 6.89 angstrom. Crystallite size of CHAp samples was 30-40 nm. The FTIR spectra showed that there are functional groups of OH-, PO43-, and CO32- at wave number around 3447, 571, and 873 cm(-1). Based on the results of the analysis, it shows that the CHAp characteristics that had successfully produced from Cerastoderma edule, Paphia undulata, and Meretrix meretrix shells were B-type CHAp.