Rapid hydrothermal flow synthesis and characterisation of carbonate and silicate-substituted calcium phosphates

Chaudhry, A.A. and Knowles, J.C. and Rehman, I. and Darr, J.A. (2013) Rapid hydrothermal flow synthesis and characterisation of carbonate and silicate-substituted calcium phosphates. JOURNAL OF BIOMATERIALS APPLICATIONS, 28 (3). pp. 448-461. ISSN 0885-3282

Full text not available from this repository.

Abstract

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.

Item Type:
Journal Article
Journal or Publication Title:
JOURNAL OF BIOMATERIALS APPLICATIONS
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/2500/2502
Subjects:
ID Code:
132933
Deposited By:
Deposited On:
17 Apr 2019 08:50
Refereed?:
Yes
Published?:
Published
Last Modified:
13 May 2020 06:19