Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Rapid hydrothermal flow synthesis and characterisation of carbonate and silicate-substituted calcium phosphates
AU - Chaudhry, A.A.
AU - Knowles, J.C.
AU - Rehman, I.
AU - Darr, J.A.
PY - 2013
Y1 - 2013
N2 - A range of crystalline and nano-sized carbonate- and silicate-substituted hydroxyapatite has been successfully produced by using continuous hydrothermal flow synthesis technology. Ion-substituted calcium phosphates are better candidates for bone replacement applications (due to improved bioactivity) as compared to phase-pure hydroxyapatite. Urea was used as a carbonate source for synthesising phase pure carbonated hydroxyapatite (CO3-HA) with ≈5 wt% substituted carbonate content (sample 7.5CO3-HA) and it was found that a further increase in urea concentration in solution resulted in biphasic mixtures of carbonate-substituted hydroxyapatite and calcium carbonate. Transmission electron microscopy images revealed that the particle size of hydroxyapatite decreased with increasing urea concentration. Energy-dispersive X-ray spectroscopy result revealed a calcium deficient apatite with Ca:P molar ratio of 1.45 (±0.04) in sample 7.5CO3-HA. For silicate-substituted hydroxyapatite (SiO4-HA) silicon acetate was used as a silicate ion source. It was observed that a substitution threshold of ∼1.1 wt% exists for synthesis of SiO4-HA in the continuous hydrothermal flow synthesis system, which could be due to the decreasing yields with progressive increase in silicon acetate concentration. All the as-precipitated powders (without any additional heat treatments) were analysed using techniques including Transmission electron microscopy, X-ray powder diffraction, Differential scanning calorimetry, Thermogravimetric analysis, Raman spectroscopy and Fourier transform infrared spectroscopy. © The Author(s) 2012 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
AB - A range of crystalline and nano-sized carbonate- and silicate-substituted hydroxyapatite has been successfully produced by using continuous hydrothermal flow synthesis technology. Ion-substituted calcium phosphates are better candidates for bone replacement applications (due to improved bioactivity) as compared to phase-pure hydroxyapatite. Urea was used as a carbonate source for synthesising phase pure carbonated hydroxyapatite (CO3-HA) with ≈5 wt% substituted carbonate content (sample 7.5CO3-HA) and it was found that a further increase in urea concentration in solution resulted in biphasic mixtures of carbonate-substituted hydroxyapatite and calcium carbonate. Transmission electron microscopy images revealed that the particle size of hydroxyapatite decreased with increasing urea concentration. Energy-dispersive X-ray spectroscopy result revealed a calcium deficient apatite with Ca:P molar ratio of 1.45 (±0.04) in sample 7.5CO3-HA. For silicate-substituted hydroxyapatite (SiO4-HA) silicon acetate was used as a silicate ion source. It was observed that a substitution threshold of ∼1.1 wt% exists for synthesis of SiO4-HA in the continuous hydrothermal flow synthesis system, which could be due to the decreasing yields with progressive increase in silicon acetate concentration. All the as-precipitated powders (without any additional heat treatments) were analysed using techniques including Transmission electron microscopy, X-ray powder diffraction, Differential scanning calorimetry, Thermogravimetric analysis, Raman spectroscopy and Fourier transform infrared spectroscopy. © The Author(s) 2012 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
KW - bioactive
KW - Calcium phosphates
KW - carbonate
KW - silicate
KW - substituted
KW - Calcium deficient apatites
KW - Carbonate-substituted hydroxyapatite
KW - Carbonated hydroxyapatites
KW - Continuous hydrothermal flow synthesis
KW - Energy dispersive x-ray spectroscopy
KW - Transmission electron microscopy images
KW - Calcium
KW - Calcium phosphate
KW - Carbonates
KW - Differential scanning calorimetry
KW - Energy dispersive spectroscopy
KW - Fourier transform infrared spectroscopy
KW - Hydrothermal synthesis
KW - Hydroxyapatite
KW - Ion sources
KW - Metabolism
KW - Silicates
KW - Silicon
KW - Thermogravimetric analysis
KW - Transmission electron microscopy
KW - Urea
KW - Volatile fatty acids
KW - X ray powder diffraction
KW - Carbonation
KW - acetic acid
KW - apatite
KW - calcium
KW - calcium carbonate
KW - calcium phosphate
KW - carbonic acid
KW - hydroxyapatite
KW - silicon
KW - silicon acetate
KW - unclassified drug
KW - urea
KW - animal experiment
KW - animal tissue
KW - article
KW - concentration (parameters)
KW - controlled study
KW - differential scanning calorimetry
KW - energy dispersive X ray spectroscopy
KW - femur condyle
KW - hydrothermal flow synthesis
KW - infrared spectroscopy
KW - nonhuman
KW - particle size
KW - rabbit
KW - Raman spectrometry
KW - roentgen spectroscopy
KW - synthesis
KW - thermogravimetry
KW - transmission electron microscopy
KW - Calcium Phosphates
KW - Microscopy, Electron, Transmission
KW - Particle Size
U2 - 10.1177/0885328212460289
DO - 10.1177/0885328212460289
M3 - Journal article
VL - 28
SP - 448
EP - 461
JO - JOURNAL OF BIOMATERIALS APPLICATIONS
JF - JOURNAL OF BIOMATERIALS APPLICATIONS
SN - 0885-3282
IS - 3
ER -