16-02-2006, 12:57 AM
<b><!--sizeo:5--><!--/sizeo-->Apatite Formation on Cobalt and Titanium Alloys by a Biomimetic Process<!--sizec--><!--/sizec--></b>
J. C. Escobedo Bocardo, M. A. López Heredia, D. A. Cortés Hernández, A. Medina RamÃrez and J. M. Almanza Robles
Posted: November 2005
AZojomo (ISSN 1833-122X) Volume 1 November 2005
<b>Abstract</b>
Ti and Co alloys were subjected to a biomimetic process. The Ti and Co alloy samples were immersed in 10M and 5M NaOH solutions, respectively. The samples were heat treated and finally, immersed in either a simulated body fluid (SBF) with a lower ionic concentration to that of human blood plasma (0.85SBF) or a simulated body fluid with a higher ionic concentration (1.3SBF) for a period of 21 days. A more modified surface, due to the chemical and heat treatment, was observed on the Ti alloys than on the Co alloys. An apatite layer was observed after the immersion of the samples in 0.85SBF for both, Ti and Co alloys. After the immersion in 0.85SBF the observed ceramic layer on the Ti alloy samples was more homogeneous and thicker than that observed on the Co alloy samples. However, the ceramic layer on both samples was not continuous along the surface. A thick apatite layer was formed on samples immersed in 1.3SBF and this was attributed to the higher ion concentration, mainly of calcium and phosphorus. The Ca/P ratios measured in the apatite layers formed in 1.3SBF were closer to that of bone.
<b>Keywords</b>
Apatite, Bioactive, Biomimetic, Simulated Body Fluid
J. C. Escobedo Bocardo, M. A. López Heredia, D. A. Cortés Hernández, A. Medina RamÃrez and J. M. Almanza Robles
Posted: November 2005
AZojomo (ISSN 1833-122X) Volume 1 November 2005
<b>Abstract</b>
Ti and Co alloys were subjected to a biomimetic process. The Ti and Co alloy samples were immersed in 10M and 5M NaOH solutions, respectively. The samples were heat treated and finally, immersed in either a simulated body fluid (SBF) with a lower ionic concentration to that of human blood plasma (0.85SBF) or a simulated body fluid with a higher ionic concentration (1.3SBF) for a period of 21 days. A more modified surface, due to the chemical and heat treatment, was observed on the Ti alloys than on the Co alloys. An apatite layer was observed after the immersion of the samples in 0.85SBF for both, Ti and Co alloys. After the immersion in 0.85SBF the observed ceramic layer on the Ti alloy samples was more homogeneous and thicker than that observed on the Co alloy samples. However, the ceramic layer on both samples was not continuous along the surface. A thick apatite layer was formed on samples immersed in 1.3SBF and this was attributed to the higher ion concentration, mainly of calcium and phosphorus. The Ca/P ratios measured in the apatite layers formed in 1.3SBF were closer to that of bone.
<b>Keywords</b>
Apatite, Bioactive, Biomimetic, Simulated Body Fluid