Synthesis and Characterization of Carbonate Hydroxyapatite from Pokea Clam Shells (Batissa Violacea Var. Celebensis) by Precipitation and Hydrothermal Methods

Hydroxyapatite Carbonate (CHA) is a material that is found to have a composition more similar to bone, with a higher bioactivity than Hydroxyapatite (HA). CHA was synthesized using precipitation and hydrothermal methods using (NH 4 ) 2 HPO 4 as a phosphate source, NH 4 HCO 3 as a carbonate source, and Pokea shells as a calcium source. In this study, the Pokea shells were crushed, calcined, and characterized based on physicochemical tests. CaO from Pokea shell contains 74.33% calcium. CHA was successfully produced by precipitation method at room temperature and hydrothermal at 120 C for 8 h. Sample characterization was carried out using X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR), and Scanning Electron Microscope Energy Dispersive X-Ray Spectroscopy (SEM-EDX). Based on XRD data, there are differences in the crystal size of CHA produced via precipitation and hydrothermal methods, where the crystal sizes of Precipitation CHA-1 and Hydrothermal CHA-2 are 6.388 nm and 25.969 nm. The FTIR results of both CHA show the functional groups typical of CHA, namely OH-, CO, CaO, PO 4 3- , and CO 3 2- . From the Ca/P EDX data results, Precipitation CHA-1 and Hydrothermal CHA-2 do not differ much, namely 1.71 and 1.69, and this value indicates that CHA has been formed.