Novel Preparation Method of Hydroxyapatite Fibers

A novel method for preparing calcium hydroxyapatite (Ca10(PO4)6(OH)2: HAp) fibers has been developed. HAp fibers can be prepared successfully by heating a compact consisting of calcium metaphosphate (s-Ca(PO3)2) fibers with Ca(OH)2 particles in air at 1000°C and subsequently treating the resultant compact with dilute aqueous HCl solution. The s-Ca(PO3)2 fibers and the Ca(OH)2 in the compact were converted into fibrous HAp and CaO phases by the heating, and the CaO phase was removed by acid-leaching. HAp fibers obtained in the present work were 40-150 µm in length and 2-10 µm in diameter. The fibers had almost the same dimensions as those of the s-Ca(PO3)2 fibers.