Y. Liu et Gh. Nancollas, CRYSTALLIZATION AND COLLOIDAL STABILITY OF CALCIUM-PHOSPHATE PHASES, JOURNAL OF PHYSICAL CHEMISTRY B, 101(18), 1997, pp. 3464-3468
The interfacial energy of calcium phosphate powders has been determine
d through contact angle measurements using thin-layer wicking techniqu
es. The much smaller interfacial energy of octacalcium phosphate (OCP)
in contact with water compared with that of hydroxyapatite (HAP) supp
orts the observation that the crystallization of the latter may be pre
ceded by an OCP phase which can serve as a template for apatite growth
. The colloidal stabilities of calcium phosphates of colloidal dimensi
ons were also investigated. The relative stabilities of OCP, dicalcium
phosphate dihydrate (DCPD), and HAP dispersions could be explained by
invoking the concepts of Lewis acid-base interactions in addition to
the two other more traditional types of interactions that are involved
in the Derjaguin-Landau-Venvey-Overbeek (DLVO) theory, namely, electr
ical double-layer repulsion and van der Waals attraction.