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Synthesis and characterization of functional gradient materials using Indian corals.
I Manjubala1, M Sivakumar, T S Sampath Kumar
1Materials Science Center, Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai - 600 025, India.
Journal of Materials Science. Materials in Medicine
|September 7, 2004
Summary
Silver oxide catalyzed the conversion of hydroxyapatite (HA) to tricalcium phosphate (TCP), creating a functional gradient material. This biphasic material exhibited stability between HA and TCP in solubility tests.
Area of Science:
- Biomaterials Science
- Ceramics Engineering
- Materials Chemistry
Background:
- Hydroxyapatite (HA) is a key component of bone mineral.
- Tricalcium phosphate (TCP) is a widely used biocompatible ceramic.
- Controlling the conversion between HA and TCP is crucial for tailored biomaterial properties.
Purpose of the Study:
- To investigate the partial conversion of HA into TCP using silver oxide (Ag2O) as a catalyst.
- To develop a functional gradient material with varying HA and TCP content.
- To analyze the structural and stability characteristics of the resulting biphasic material.
Main Methods:
- Thermal analysis of HA powder mixed with 5 mol % Ag2O.
- Formation of a functional gradient by surface application of Ag2O on HA compacts.
- Firing at 700°C in air.
- X-ray powder diffraction (XRD) for phase analysis.
- In vitro solubility study in phosphate buffer (pH 7.2).
Main Results:
- Silver oxide decomposition occurred around 550°C in the presence of HA.
- X-ray diffraction confirmed the formation of alpha-TCP induced by Ag2O decomposition.
- A functional gradient of alpha-TCP was observed, decreasing with depth from the surface.
- The biphasic HA-TCP material showed intermediate stability in vitro compared to pure HA and TCP.
Conclusions:
- Silver oxide effectively catalyzes the partial conversion of HA to alpha-TCP.
- This method allows for the creation of functional gradient materials with tunable HA/TCP ratios.
- The resulting biphasic material possesses intermediate solubility, suggesting potential for controlled degradation in biomedical applications.