Synthesis and Characteristic of Hydroxyapatite from Tilapia Fish Scale via Heat Treatment Technique

This research aimed to study the preparation and synthesis of hydroxyapatite from tilapia fish scales. The tilapia fish scale was washed with water to remove the tissue and other contaminants. To remove protein and gelatin, the tilapia fish scale was soaked in hydrochloric and sodium hydroxide solutions, respectively. The tilapia fish scale was grounded and heated with different temperatures at 400, 800 and 1,200°C. The crystal structure of the tilapia fish scale before and after heated with different temperatures was investigated by X-ray diffraction (XRD). The chemical function group and morphology of the tilapia fish scales before and after heated with different temperatures were analyzed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), respectively. The XRD result showed that the crystal structure of tilapia fish scale before heating consists of brushite and hydroxyapatite. However, the XRD result cannot detect the gelatin and collagen structure. While the FTIR result showed that the tilapia fish scale before heating has the functional group of amide III, indicating the gelatin and collagen structure. After heating at 400°C, the XRD result showed that the tilapia fish scale has a pure hydroxyapatite phase. The crystallinity of hydroxyapatite increases with increasing the heating temperature. These results were confirmed by the FTIR and SEM results. This research indicates that the tilapia fish scale can be used as a precursor for synthesizing a pure hydroxyapatite with high crystallinity.