Abstract
We have studied the structure of hydroxyapatite (HA) powders prepared by hydrolyzing dicalcium phosphate dihydrate (DCPD) in an aqueous sodium acetate solution at a temperature of 60°C for 16 h or a longer time. The results demonstrate that the HA in the powders has a distorted structure. The Baur’s distortion index for the PO4 tetrahedra is DI(TO) ≃ 0.03, whereas hydroxyapatite single crystals have DI(TO) ≃ 0.005. The powders are similar in structural parameters to calcium-deficient HAs: they have Ca/P ≃ 1.6 and an imperfect substructure (crystallite size of ≃30 nm) and contain sodium impurities. The structural features of the HA powders are analyzed in the context of their ability to biodegrade (dissolve).
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Suzuki, O., Octacalcium phosphate: osteoconductivity and crystal chemistry, Acta Biomater., 2010, vol. 6, pp. 3379–3387.
Barinov, S.M. and Komlev, V.S., Osteoinductive ceramic materials for bone tissue restoration: octacalcium phosphate (review), Inorg. Mater.: Appl. Res., 2010, vol. 1, no. 3, pp. 34–41.
Dorozhkin, S.V., Calcium orthophosphates. Occurrence, properties, biomineralization, pathological, calcification and biomimetic applications, Biomatter, 2011, vol. 1, no. 2, pp. 121–164.
Natsuko Ito, Masanobu Kamitakahara, Masahiro Yoshimura, and Koji Ioku, Importance of nucleation in transformation of octacalcium phosphate to hydroxyapatite, Mater. Sci. Eng., C, 2014, vol. 40, pp. 121–126.
Elliott, J.C., Wilson, R.M., and Dowker, S.E.P., Apatite structures, Adv. X-ray Anal., 2002, vol. 45, pp. 172–181.
Shamrai, V.F., Karpikhin, A.E., Sirotinkin, V.P., Kalita, V.I., and Komlev, D.I., Evolution of the calcium hydroxyapatite crystal structure under plasma deposition and subsequent reducing treatment, Crystallogr. Rep., 2014, vol. 59, no. 2, pp. 179–185.
Fedotov, A.Yu., Komlev, V.S., Teterina, A.Yu., et al., Preparation of octacalcium phosphate from calcium carbonate powder, Inorg. Mater., 2013, vol. 49, no. 11, pp. 1148–1151.
Zhan, J., Tseng, Y.H., Chan, J.C.C., et al., Biometric formation of hydroxyapatite nanorods by a single-crystal-to-single-crystal transformation, Adv. Funct. Mater., 2005, vol. 15, pp. 2005–2010.
Iijima, M., Kamemizu, H., Wakamatsu, N., et al., Transition of octacalcium phosphate to hydroxyapatite in solution at pH 7.4 and 37°C, J. Cryst. Growth, 1997, vol. 181, pp. 70–78.
Popa, N.C., The (hkl) dependence of diffraction-line broadening caused by strain and size for all Laue groups in Rietveld refinement, J. Appl. Crystallogr., 1998, vol. 31, pp. 176–180.
Baur, W.H., The geometry of polyhedral distortion. Predictive relationships for the phosphate group, Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem., 1974, vol. 30, pp. 1195–1215.
Smith, A.N., Posner, A.M., and Quirk, J.P., A model describing the kinetics of dissolution of hydroxyapatite, J. Colloid Interface Sci., 1977, vol. 62, pp. 475–494.
Author information
Authors and Affiliations
Corresponding author
Additional information
Original Russian Text © A.E. Karpikhin, A.Yu. Fedotov, V.S. Komlev, S.M. Barinov, V.P. Sirotinkin, A.S. Gordeev, V.F. Shamrai, 2016, published in Neorganicheskie Materialy, 2016, Vol. 52, No. 2, pp. 205–210.
Rights and permissions
About this article
Cite this article
Karpikhin, A.E., Fedotov, A.Y., Komlev, V.S. et al. Structure of hydroxyapatite powders prepared through dicalcium phosphate dihydrate hydrolysis. Inorg Mater 52, 170–175 (2016). https://doi.org/10.1134/S0020168516020060
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S0020168516020060