TY - JOUR
T1 - Influence of synthesis and sintering parameters on the characteristics of carbonate apatite
AU - Landi, Elena
AU - Tampieri, Anna
AU - Celotti, Giancarlo
AU - Vichi, Lucia
AU - Sandri, Monica
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2004/5
Y1 - 2004/5
N2 - A new method to synthesise carbonate-substituted hydroxyapatite (CHA) powder has been set up introducing a CO2 flux, as a source of carbonate, in the HA synthesis process based on the neutralisation reaction. The reactants are abundant and inexpensive. The yield is good compared to other CHA powder synthesis. The reaction may be performed at low temperature and without pH control and does not produce any by-products. The influence of the synthesis parameters (temperature, H3PO4 solution dropping rate, i.e. reaction time, CO2 flux, ageing time) has been tested to optimise the process conditions in order to obtain the highest carbonation degree and favour the B-type CHA precipitation with respect to A-type one. The prepared powder (5.8wt% of total carbonate with an A/B ratio of 0.78) was thermally treated at various temperatures in the range 500-1400°C in different atmospheres (air, wet and dry carbon dioxide). The thermal treatments were performed with a double aim, to eliminate selectively the carbonate groups in A-position maintaining the B-type substitution, and to evaluate the thermal stability of the CHA and the total loss of carbonate as a function of temperature. The thermal treatment at 900°C in wet CO 2 gave the best result in terms of a high carbonate residue and a low A/B ratio. We also investigate the use of different techniques (inductively coupled plasma, TGA, Fourier transformed infrared spectroscopy, X-ray diffraction) for characterising CHA and calculating sensitivity and accuracy in the quantification of carbonate ions for each molecular site.
AB - A new method to synthesise carbonate-substituted hydroxyapatite (CHA) powder has been set up introducing a CO2 flux, as a source of carbonate, in the HA synthesis process based on the neutralisation reaction. The reactants are abundant and inexpensive. The yield is good compared to other CHA powder synthesis. The reaction may be performed at low temperature and without pH control and does not produce any by-products. The influence of the synthesis parameters (temperature, H3PO4 solution dropping rate, i.e. reaction time, CO2 flux, ageing time) has been tested to optimise the process conditions in order to obtain the highest carbonation degree and favour the B-type CHA precipitation with respect to A-type one. The prepared powder (5.8wt% of total carbonate with an A/B ratio of 0.78) was thermally treated at various temperatures in the range 500-1400°C in different atmospheres (air, wet and dry carbon dioxide). The thermal treatments were performed with a double aim, to eliminate selectively the carbonate groups in A-position maintaining the B-type substitution, and to evaluate the thermal stability of the CHA and the total loss of carbonate as a function of temperature. The thermal treatment at 900°C in wet CO 2 gave the best result in terms of a high carbonate residue and a low A/B ratio. We also investigate the use of different techniques (inductively coupled plasma, TGA, Fourier transformed infrared spectroscopy, X-ray diffraction) for characterising CHA and calculating sensitivity and accuracy in the quantification of carbonate ions for each molecular site.
KW - Carbonate site evaluation
KW - Carbonate-substituted hydroxyapatite (CHA)
KW - CHA characterisation
KW - CHA synthesis
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U2 - 10.1016/j.biomaterials.2003.08.026
DO - 10.1016/j.biomaterials.2003.08.026
M3 - Article
C2 - 14738839
AN - SCOPUS:0347761352
VL - 25
SP - 1763
EP - 1770
JO - Biomaterials
JF - Biomaterials
SN - 0142-9612
IS - 10
ER -