FTIR study of carbonate loss from carbonated apatites in the wide temperature range

• Published in: Journal of biomedical materials research. Part B, Applied biomaterials Vol. 71B; no. 2; pp. 441 - 447
• Main Authors: Rau, J.V., Cesaro, S. Nunziante, Ferro, D., Barinov, S.M., Fadeeva, I.V.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15-11-2004
• Subjects: Apatites - analysis; Carbon - analysis; carbonated apatites; Carbonates - analysis; ceramics; Magnesium; Particle Size; Spectroscopy, Fourier Transform Infrared; Temperature; thermal stability; X-Ray Diffraction
• ISSN: 1552-4973; 1552-4981
• DOI: 10.1002/jbm.b.30111

The mineral constituent of bone tissue is a carbonate‐substituted apatite (CHA). The thermal stability of the CHA has been revealed to depend on the substitution type and degree, although relatively little is known about this behavior. The aim of this study was to investigate the carbonate loss from synthetic CHAs in equilibrium conditions in a wide temperature range. An approach based on FTIR spectroscopy of condensed gas phase was applied to evaluate the CO and CO2 release with increasing temperature. Four different CHAs were studied, which were prepared by either precipitation from solution or the solid‐state interaction. The samples differ from each other by the substitution degree. In one of the samples calcium was partially substituted by magnesium. Decomposition was shown to start at surprisingly low temperature, about 400°C, and the CO content increases monotonously with the increase of temperature. The CO2 content goes through a maximum due to its decomposition into carbon monoxide and oxygen, the temperature of this maximum being strongly dependent on the chemical synthesis route. Therefore, control of the sintering atmosphere with respect to the CO2/CO ratio is needed when preparing the carbonated apatite bioceramics. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 71B: 441–447, 2004