Synthesis and characterization of hydroxyapatite based on green mussel shells (Perna viridis) with calcination temperature variation using the precipitation method

Hydroxyapatite (HA) from green mussel shells (Perna viridis) has been successfully synthesized with a variation of calcination temperature using the precipitation method. Green mussel shells were calcined in a furnace at temperatures of 650°C, 750°C, 850°C and 950°C for 2 h to obtain calcium oxide. AAS results show that the levels of Ca for calcination at temperatures of 650°C, 750°C, 850°C, and 950°C are 30.4333%, 34.3030%, 37.1080% and 49.5757%, respectively. X-Ray diffractometer results show that the crystallization of calcium oxide with calcination at 950°C is high because of its large crystallite size and small microstrain. SEM results reveal some relief lines on the particle surfaces, products of the high temperatures (850°C and 950°C) during calcination. TGA analysis indicates that green mussel shells calcined at 950°C experience a significant weight loss of 22.386%. XRD analysis shows that the HA with a stirring time of 60 min exhibits high crystallinity, with a large crystallite size of (82.50± 5.3) nm and the smallest microstrain value (0.0061). DTA/TGA analysis reveals that HA with a stirring time of 60 min undergoes faster weight loss in the temperature of 426.33°C, with a weight loss of 0.834%. The FTIR spectra show that HA with a stirring time of 60 min shows the functional group of CO32- only at 875.62 cm-1. This indicates that the smples’sCO32- is low. SEM results demonstrate that HA with a stirring time of 60 min has a small agglomerate shape and thick particles structure. EDX analysis reveals that HA with a stirring time of 60 min exhibits a Ca/P molar ratio of 1.67, the Ca/P molar ratio of HA.