Formation of fluoridated hydroxyapatite from tricalcium phosphate (TCP) in organic media

摘要

Solvothermal reactions of alpha -tricalcium phosphate ( alpha -TCP) with NH_4F were investigated in water- organic solvent system. In the system using a series of aliphatic alcohols the formation of fluoridated hydroxyapatite [Ca_(10)(PO_4)_6(OH)_(2-x)F_x] (FHAp) was confirmed. The formation rate of FHAp from alpha -TCP and the shape and size of FHAp were influenced by the hydrophobicity of aliphatic alcohols similarly to the formation of HAp from alpha -TCP. The product obtained in water-1-octanol biphasic system was a mixture of needle-like particles (approx0.5 x 1approx4 mu m) with ultrafine particles (approx0.1 mu m), whereas the product in water (in the absence of organic solvent) consisted of fine particles less than 1 mu m. The formation rate showed unusual dependence on the concentration of fluoride ion and on the reaction temperature.