Calcium hydroxyapatite/whitlockite obtained from dairy products: Simple, environmentally benign and green preparation technology

This study presents synthesis and characterization of calcium hydroxyapatite (Ca10(PO4)6(OH)2, CHAp) and whitlockite (Ca18Mg2H2(PO4)14) composite obtained from dairy product. First, calcium containing powders were precipitated from whey permeate by combining the effect of alkaline pH and temperature. Subsequently a calcium containing phase was collected using membrane filtration and spray-dried. Finally, the temperature treatment was applied to eliminate the organic phase and purify calcium containing compounds. The mechanism of thermal decomposition of dairy calcium powder (DCP) was investigated using thermogravimetric analysis coupled with differential scanning calorimetry (TG-DSC). The phase composition, structural and morphological features of the final products were studied by X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM).