TY - JOUR
T1 - Synthesis and optimization of the production of millimeter-sized hydroxyapatite single crystals by Cl-OH ion exchange
AU - García-Tuñon, E.
AU - Franco, J.
AU - Eslava, S
AU - Bhakhri, V.
AU - Saiz, E.
AU - Giuliani, F.
AU - Guitián, F.
PY - 2013/3/1
Y1 - 2013/3/1
N2 - Millimeter-sized hydroxyapatite (HA) single crystals were synthesized from chlorapatite (ClAp) crystals via the ionic exchange of Cl for OH at high temperature. X-ray diffraction, Fourier-transform infrared spectroscopy, and chloride content measurements were used to follow the progress of this conversion, and to assess the effect of the experimental conditions (temperature, time, and atmosphere). Cl→OH exchange took place homogeneously and was enhanced by firing in wet air. After firing at 1425°C for 2 h 92% of the Cl ions were exchanged by OH while maintaining crystal integrity. Temperatures above 1450°C damaged the surface of the crystals, destroying the hexagonal habit at 1500°C. The composition of these apatite crystals was close to bone mineral content. Their nanoindentation hardness (8.7 ± 1.0 GPa) and elastic nanoindentation modulus (120 ± 10 GPa) were similar to those of the starting ClAp (6.6 ± 1.5 GPa, and 110 ± 15 GPa, respectively). However, their average flexural strength was ~25% lower due to the formation of defects during the thermal treatments.
AB - Millimeter-sized hydroxyapatite (HA) single crystals were synthesized from chlorapatite (ClAp) crystals via the ionic exchange of Cl for OH at high temperature. X-ray diffraction, Fourier-transform infrared spectroscopy, and chloride content measurements were used to follow the progress of this conversion, and to assess the effect of the experimental conditions (temperature, time, and atmosphere). Cl→OH exchange took place homogeneously and was enhanced by firing in wet air. After firing at 1425°C for 2 h 92% of the Cl ions were exchanged by OH while maintaining crystal integrity. Temperatures above 1450°C damaged the surface of the crystals, destroying the hexagonal habit at 1500°C. The composition of these apatite crystals was close to bone mineral content. Their nanoindentation hardness (8.7 ± 1.0 GPa) and elastic nanoindentation modulus (120 ± 10 GPa) were similar to those of the starting ClAp (6.6 ± 1.5 GPa, and 110 ± 15 GPa, respectively). However, their average flexural strength was ~25% lower due to the formation of defects during the thermal treatments.
UR - http://www.scopus.com/inward/record.url?scp=84875264758&partnerID=8YFLogxK
UR - http://dx.doi.org/10.1111/jace.12199
U2 - 10.1111/jace.12199
DO - 10.1111/jace.12199
M3 - Article
AN - SCOPUS:84875264758
SN - 0002-7820
VL - 96
SP - 759
EP - 765
JO - Journal of the American Ceramic Society
JF - Journal of the American Ceramic Society
IS - 3
ER -