TY - JOUR
T1 - Kinetics of conversion of brushite coatings to hydroxyapatite in alkaline solution
AU - Da Rocha, Daniel Navarro
AU - Da Silva, Marcelo H.Prado
AU - De Campos, José Brant
AU - Marçal, Rubens L.Santana Blazutti
AU - Mijares, Dindo Q.
AU - Coelho, Paulo G.
AU - Cruz, Leila Rosa
N1 - Funding Information:
This work was supported by the following Brazilian agencies: FAPERJ (project 2015005263 ), CNPq (project 140144/2012-9 ), and CAPES (project 10.980/13-0 ).
Publisher Copyright:
© 2018 Brazilian Metallurgical, Materials and Mining Association.
PY - 2018
Y1 - 2018
N2 - 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.
AB - 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.
KW - Activation energy
KW - Avrami equation
KW - Conversion kinetics
KW - Hydroxyapatite
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U2 - 10.1016/j.jmrt.2018.02.002
DO - 10.1016/j.jmrt.2018.02.002
M3 - Article
AN - SCOPUS:85044425670
SN - 2238-7854
VL - 7
SP - 479
EP - 486
JO - Journal of Materials Research and Technology
JF - Journal of Materials Research and Technology
IS - 4
ER -