Surface Structure, Hydration and Cationic Sites of Nanohydroxyapatite


Article Preview

In this work, we studied the surface/water interaction properties of a pure calcium hydroxyapatite (HA) and their modifications as a consequence of the partial Ca2+/Mg2+ (MHA) substitution by means of IR spectroscopy and microcalorimetry of adsorbed water. IR data indicated that water molecules in direct contact with the surface of HA are coordinated to surface cations and experience H-bond significantly stronger than in liquid water. The heats of adsorption associated to such interactions are very high, being twice-triple the heat of liquefaction of water. Interestingly, water experiences H-bond higher than in its bulk liquid state also in the second layer. Finally the entering in the material of Mg2+ ions was shown to significantly affect the affinity of the material toward water and the properties of its hydration layers.



Key Engineering Materials (Volumes 361-363)

Main Theme:

Edited by:

Guy Daculsi and Pierre Layrolle




L. Bertinetti et al., "Surface Structure, Hydration and Cationic Sites of Nanohydroxyapatite", Key Engineering Materials, Vols. 361-363, pp. 87-90, 2008

Online since:

November 2007




[1] B. Kasemo: Surf. Sci. Vol. 500 (2002), p.656.

[2] C. J. Wilson, R. E. Clegg, D. I. Leavesley and M. J. Pearcy: Tissue Eng. Vol. 11 (2005), p.1.

[3] T.J. Webster and J.U. Ejiofor: Biomaterials Vol. 25 (2004), p.4731.

[4] T.J. Webster, C. Ergun, R. Doremus, R. Siegel and R. Bizios: Biomaterials Vol. 22 (2001), p.1327.

[5] L. Bertinetti, A. Tampieri, E. Landi, C. Ducati, P.A. Midgley, S. Coluccia and G. Martra: J. Phys Chem. C Vol. 111 (2007), p.4027.

[6] M. Takeuchi, L. Bertinetti, G. Martra, S. Cosuccia and M. Anpo: Appl Cat A Vol 307 (2005), p.13.

[7] V. Bolis, C. Busco and P. Ugliengo: J. Phys. Chem. B Vol. 110 (2006), p.14849.