Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-29T17:11:17.310Z Has data issue: false hasContentIssue false

Synthesis of calcium phosphate crystals in a silica hydrogel containing phosphate ions

Published online by Cambridge University Press:  31 January 2011

Taishi Yokoi*
Affiliation:
Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
Masakazu Kawashita
Affiliation:
Department of Biomedical Engineering, Graduate School of Biomedical Engineering, Tohoku University, Aramaki-Aoba, Aoba-ku, Sendai 980-8579, Japan
Chikara Ohtsuki
Affiliation:
Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
*
a) Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

Calcium phosphate crystals were synthesized by diffusing calcium ions into silica hydrogels containing phosphate ions. Hydroxyapatite [HAp, Ca10(PO4)6(OH)2] and octacalcium phosphate [OCP, Ca8(HPO4)2(PO4)4.5H2O] with different types of crystal morphology were formed in the gel. The HAp had an irregular or rod shape, a few micrometers in length, while the OCP had an irregular, spherulite, rod- or ribbonlike shape, ranging in size from a few micrometers to several tens of micrometers, depending on the amount of phosphoric acid added and the reaction temperature. The morphology of the OCP changed from an irregular shape to a ribbonlike or rod shape, via a spherulite shape, depending on the amount of phosphoric acid added and the reaction temperature. The degree of supersaturation of the reaction environment and the rate-determining step in the HAp and OCP crystal growth mechanism have been ascribed to the changes in crystal morphology of the HAp and OCP.

Type
Articles
Copyright
Copyright © Materials Research Society 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1Grassmann, O. and Löbmann, P.: Biomimetic nucleation and growth of CaCO3 in hydrogels incorporating carboxylate groups. Biomaterials 25, 277 (2004).CrossRefGoogle ScholarPubMed
2Fernández-Díaz, L., Astilleros, J.M., and Pina, C.M.: The morphology of calcite crystals grown in a porous medium doped with divalent cations. Chem. Geol. 225, 314 (2006).CrossRefGoogle Scholar
3Henisch, H.K., Dennis, J., and Hanoka, J.I.: Crystal growth in gels. J. Phys. Chem. Solids 26, 493 (1965).Google Scholar
4Ouyang, H.M.: Effects of temperature on growth and aggregation of calcium oxalate in presence of various carboxylic acids in silica gel systems. Mater. Sci. Eng. 26, 679 (2006).Google Scholar
5Mann, S.: Biomineralization Principle and Concepts in Bioinorganic Materials Chemistry (Oxford University Press, UK, 2001), pp. 89124.CrossRefGoogle Scholar
6Dorozhkin, S.V. and Epple, M.: Biological and medical significance of calcium phosphates. Angew. Chem. Int. Ed. 41, 3130 (2002).3.0.CO;2-1>CrossRefGoogle ScholarPubMed
7Brown, W.E., Eidelman, N., and Tomazic, B.: Octacalcium phosphate as a precursor in biomineral formation. Adv. Dent. Res. 1, 306 (1987).CrossRefGoogle ScholarPubMed
8Furuichi, K., Oaki, Y., Ichimiya, H., Komotori, J., and Imai, H.: Preparation of hierarchically organized calcium phosphate–organic polymer composites by calcification of hydrogel. Sci. Technol. Adv. Mater. 7, 219 (2006).CrossRefGoogle Scholar
9Göbel, C., Simon, P., Buder, J., Tlatlik, H., and Kniep, R.: Phase formation and morphology of calcium phosphate-gelatine-composites grown by double diffusion technique: The influence of fluoride. J. Mater. Chem. 14, 2225 (2004).CrossRefGoogle Scholar
10Villacampa, A.I. and García-Ruiz, J.M.: Synthesis of new hydroxyapatite-silica composite material. J. Cryst. Growth 211, 111 (2000).CrossRefGoogle Scholar
11Sivakumar, G.R., Girija, E.K., Kalkura, S.N., and Subramanian, C.: Crystallization and characterization of calcium phosphates: Brushite and monetite. Cryst. Res. Technol. 33, 197 (1998).Google Scholar
12Imai, H., Oaki, Y., and Kotachi, A.: A biomimetic approach for hierarchically structured inorganic crystals through self-organization. Bull. Chem. Soc. Jpn. 79, 1834 (2006).CrossRefGoogle Scholar
13Ohtsuki, C., Kokubo, T., and Yamamuro, T.: Mechanism of apatite formation on CaO–SiO2–P2O5 glasses in a simulated body fluid. J. Non-Cryst. Solids 143, 84 (1992).CrossRefGoogle Scholar
14Elliott, J.C.: Structure and Chemistry of the Apatites and Other Calcium Orthophosphates (Elsevier Science, The Netherlands, 1994), pp. 13, 16, 24, 28, 32, 33, 120, and 157.Google Scholar
15Heughebaertt, J.C. and Nancollas, G.H.: Kinetics of crystallization of octacalcium phosphate. J. Phys. Chem. 88, 2478 (1984).CrossRefGoogle Scholar