Kinetics of conversion of brushite coatings to hydroxyapatite in alkaline solution
| Autor: | Paulo G. Coelho, Leila Rosa de Oliveira Cruz, José Brant de Campos, Marcelo Henrique Prado da Silva, Daniel Navarro da Rocha, Dindo Q. Mijares, Rubens Lincoln Santana Blazutti Marçal |
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| Rok vydání: | 2018 |
| Předmět: |
lcsh:TN1-997
Materials science Rietveld refinement Kinetics Metals and Alloys Nucleation 02 engineering and technology Activation energy 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Surfaces Coatings and Films Biomaterials Avrami equation Chemical engineering Phase (matter) Ceramics and Composites Brushite 0210 nano-technology Dissolution lcsh:Mining engineering. Metallurgy |
| Zdroj: | Journal of Materials Research and Technology, Vol 7, Iss 4, Pp 479-486 (2018) |
| ISSN: | 2238-7854 |
| Popis: | This work describes the kinetics of conversion of brushite coatings, produced by chemical deposition, to hydroxyapatite. The conversion was performed in alkaline solution at three temperatures: 50 °C, 55 °C, and 60 °C. The evolution of the transformation was assessed by X-ray diffraction, and the phase fractions were determined by Rietveld refinement. The Johnson–Mehl–Avrami equation was applied to the data in order to describe the conversion mechanisms. The value of 42 kJ/mol obtained for the conversion activation energy is of the same order as found in similar surface-controlled dissolution processes. The Avrami exponent was n = 3.5, which is consistent with an interface-controlled growth of three-dimensional HA crystals with decreasing nucleation rate. Keywords: Hydroxyapatite, Conversion kinetics, Activation energy, Avrami equation |
| Databáze: | OpenAIRE |
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