Phase Transformations in the Spontaneous Precipitation of Calcium Phosphate*
نویسندگان
چکیده
Recent experimental evidence suggests that octacalcium phosphate (OCP) is a necessary precursor to hydroxyapaptite in the amorphous-crystalline transformation that occurs after the spon..: taneous precipitation of calcium phosphate in the pH range 7.00-9.25. The transformation appears to occur by heterogeneous nucleation of OCP by the initially formed amorphous calcium phosphate (ACP) phase. ACP itself seems to have a well-defined composition with a solubility determining molecular unit. At pH greater than 9.25 the mechanism for the transformation seems to change. At liigh pH OCP becomes thermodynamically unstable the ACP structure seems to break down.
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