Abstract
Interfacial reaction in a multiple emulsion, which is one of methods for
producing inorganic microspheres, was applied to synthesize hydroxyapatite. The
multiple emulsion was a W/O/W emulsion, made of dipotassium hydrogen phosphate
solution as an inner aqueous phase, benzene as an oil phase, and calcium nitrate solution
as an outer aqueous phase. The reaction was carried out in the multiple emulsion for 24 hours at
323 K. The crystalline phase was varied with an initial pH of the inner aqueous
phase, and single phase hydroxyapatite was synthesized at an initial pH of 12. The
products were composed of porous microspheres of less than 3