Controls on calcium phosphate cluster formation

Authors: E Valsami-Jones (Natural History Museum) , Paul Schofield (Natural History Museum) , Nicholas Terrill (Diamond Light Source) , A Martin (CLRC Daresbury Laboratory)
Co-authored by industrial partner: No

Type: Poster

State: Published (Approved)
Published: January 2004

Abstract: Calcium phosphate cluster formation leads to the nucleation of apatite. Apatite controls phosphorus availability in the geosphere and is also an important biomineral (e.g. bone, tooth). Formation of apatite at the atomic scale is believed to take place via the formation of a Ca3 (PO4 )2 precursor. Very little is currently known about the nature and evolution (in saturated aqueous solutions) of this precursor, and how this may be affected/controlled by the presence of organic species. Using the materials processing beamline, 6.2, at Daresbury Synchrotron Radiation Source for in-situ simultaneous small- and wide- angle X-ray scattering (SAXS/WAXS) experiments, we were able to to monitor apatite nucleation from supersaturated solutions at times scales of up to 30 minutes and at 10 second resolution. Our aim was to test the influence of a range of organic ligands (citrate, oxalate, osteocalcin) on nucleation and growth. Our preliminary observations suggest that organic ligands affect both the onset and the rate of crystal formation and growth, as well as the settling properties of apatite nucleating from a supersaturated solution (Figure 1). We discuss our results in the context of the precipitating apatite, as a proxy for bioapatites.

Subject Areas: Chemistry

Technical Areas:

Added On: 10/11/2010 08:51

Discipline Tags:

Physical Chemistry Chemistry

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