Synthesis and microstructural characterization of nano-size calcium phosphates with different stoichiometry

Date

2011-04-01

Author

Ergun, Celaletdin
Evis, Zafer
Webster, Thomas J.
Sahin, Filiz Cinar

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Calcium phosphates with Ca/P molar ratios of 0.5, 0.75, 1.33, 1.5, 1.55, 1.67, 2.0, and 2.5 were synthesized by a wet chemistry precipitation method and sintered at 500 degrees C, 700 degrees C, 900 degrees C, 1100 degrees C and 1300 degrees C for 2 h. Presence of phases and microstructures of calcium phosphates were determined by X-ray diffraction and scanning electron microscopy. In all different Ca/P ratios, the precipitated phase was always hydroxyapatite with very small size and/or partial disorderness regardless of the Ca/P ratios in the starting precipitating medium. For samples with 0.5 and 0.75 Ca/P ratios in starting solution, tricalcium phosphate and calcium pyrophosphate phases were observed. In contrast, for samples with 1.0 and 1.33 Ca/P ratios, the only stable phase was tricalcium phosphate. For the samples with Ca/P ratio of 1.5, the tricalcium phosphate phase was dominant. However, small amounts of hydroxyapatite started to appear. For samples with Ca/P ratio of 1.67, the hydroxyapatite phase was dominant. Lastly, for samples with the Ca/P ratios of 2.0 and 2.5, the CaO phase started to appear in addition to the hydroxyapatite phase which was the dominant phase. Moreover, the average grain size, porosity (%) and the average pore size decreased with increasing the Ca/P ratios. (c) 2010 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Subject Keywords

Process Chemistry and Technology, Materials Chemistry, Electronic, Optical and Magnetic Materials, Surfaces, Coatings and Films, Ceramics and Composites

URI

https://hdl.handle.net/11511/42470

Journal

CERAMICS INTERNATIONAL

DOI

https://doi.org/10.1016/j.ceramint.2010.11.004

Collections

Department of Engineering Sciences, Article

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Citation Formats

C. Ergun, Z. Evis, T. J. Webster, and F. C. Sahin, “Synthesis and microstructural characterization of nano-size calcium phosphates with different stoichiometry,” CERAMICS INTERNATIONAL, pp. 971–977, 2011, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/42470.