Mechanochemical behavior of CaCO3–P2O5–CaF2 system to produce carbonated fluorapatite nanopowder

The influence of milling time on mechanochemical behavior of CaCO3–P2O5–CaF2 system to produce carbonated fluorapatite nanopowder was studied. Results showed that the formation of n-CFAp was influenced noticeably by the milling time. At the beginning of milling (up to 30 min), CaF2 and CaCO3 were dominant phases, while P2O5 disappeared entirely due to its very high hydrophilic nature. With increasing the milling time to 600 min, the progressive mechanochemical reaction was completed which resulted in the formation of nanosized B-type carbonated fluorapatite. According to the obtained data, crystallite size of the product decreased from 77±4 to 69±3 nm when the milling time increased from 300 to 600 min, respectively. Microscopic observations illustrated that the final product had a cluster-like structure which was composed of both the spheroidal and ellipsoidal particles with an average size of around 45 and 90 nm, respectively. The present findings suggest that the room-temperature solid-state reaction can lead to the formation of nanostructured carbonated fluorapatite which can be a promising candidate for using in biomedical applications.