Synthesis of hydroxyapatite/fluoroapatite solid solution by a sol-gel method

A sol-gel method is developed to synthesize hydroxyapatite (HA)/fluoroapati te (FA) solid solution for providing a basis of preparation of the solid so lution film or coating. Calcium nitrate-4 hydrate, phosphoric pentoxide and trifluoroacetic acid (TFA) were used as the precursors. Triethanolamine (T EA) was used as a promoter for incorporating fluorine into Ca phosphates. M ixed ethanol solutions of the Ca and P precursors in Ca/P ratio of 1.67 wit h different amounts of TFA and TEA were prepared; the mixed solutions were dried on a hot plate to convert them to the as-prepared powders. After the powders were calcined at temperatures up to 900 degreesC, HA/FA solid solut ions were obtained. It was found that the fluorine contents in the apatite were dependent on the amounts of TFA and TEA in the mixed solutions. (C) 20 01 Elsevier Science B.V. All rights reserved.