Early Stages of Calcium Phosphate Formation on Bioactive Borosilicate Glass in Aqueous Phosphate Solution
The conversion of bioactive glass to a calcium phosphate material, typically hydroxyapatite (HA), by solution-precipitation reactions in aqueous phosphate solution, has been commonly reported. This paper describes the structural and compositional characteristics of the calcium phosphate material formed during the early-stage conversion (o5 h) of a borosilicate glass (designated H12) in aqueous phosphate solution. Disks of H12 glass were reacted with 0.25M K2HPO4 solution with a starting pH57.0 at 371C. The structure and composition of the product layer were characterized using thin film X-ray diffraction, scanning electron microscopy, and Fourier transform infrared reflectance spectroscopy. For reaction times o5 h, the results indicated the formation of brushite (CaHPO4 .2H2O) with coarse, plate-like crystals. In comparison, the formation of HA with small needle-like crystals was found at later times. This early-stage formation of brushite has not been reported in previous studies of converting bioactive silicate and borate glasses in aqueous phosphate solution.
Y. Li et al., "Early Stages of Calcium Phosphate Formation on Bioactive Borosilicate Glass in Aqueous Phosphate Solution," Journal of the American Ceramic Society, John Wiley & Sons, May 2008.
The definitive version is available at http://dx.doi.org/10.1111/j.1551-2916.2007.02140.x
Materials Science and Engineering
Keywords and Phrases
Aqueous Phoshate Solution; Bioacative Borosilicate Glass; Bioactive Glass; Borosilicate Glass; Calcium Phosphate
Article - Journal
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