Synthesis of chicken eggshell based nanofluorapatite using sonochemical and microwave-assisted precipitation methods

Fluorapatite (Ca10(PO4)6F2) is a fluorinated calcium phosphate that has high chemical and structural stability. Therefore, it is suitable to cover the outer layer of teeth. A variety of methods and synthetic chemicals have been used to produce fluorapatite. This paper reports the synthesis of nanofluorapatite using sonochemical and precipitation methods with chicken eggshells were used as the natural sources of calcium. The synthesis was also assisted by microwave irradiation, after precipitation processes, to be more efficient and faster. The irradiation was applied at a microwave power of 200 W and 400 W for 30 minutes and 45 minutes, respectively. The effect of ultrasonication amplitude was also observed in this experiment. Two different amplitudes applied are 20% and 40% of the maximum. The results reveal that accurate composition of CaO, H3PO4, and NH4F are needed to obtain pure chicken eggshell based fluorapatite as presented by X-ray diffractometer. This result is supported by Fourier Transform Infrared Spectrophotometer (FTIR) showing the presence of fluorapatite functional groups. Scanning Electron Microscope (SEM) with Energy-dispersive X-ray (EDX) spectroscopy was used to evaluate the surface morphology of the samples and the elements present near the surface. The scanning spectroscopy shows that the samples contained the elements of fluorapatite which are C, Ca, O, P and F. It was also presented by the microscope that the average particle sizes at a point were in the range of 68-117 nm, polygonal in shape and agglomerates.