An examination of the calcium and strontium site distribution in bioactive glasses through isomorphic neutron diffraction, X-ray diffraction, EXAFS and multinuclear solid state NMR

Martin, R.A., Twyman, H.L., Rees, G.J., Barney, E.R., Moss, Rob M., Smith, J.M., Hill, R.G., Cibin, G., Charpentier, T., Smith, M.E., and others. (2012) An examination of the calcium and strontium site distribution in bioactive glasses through isomorphic neutron diffraction, X-ray diffraction, EXAFS and multinuclear solid state NMR. Journal of Materials Chemistry, 22 (41). pp. 22212-22223. ISSN 0959-9428. (doi:10.1039/c2jm33058j) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

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Official URL
http://dx.doi.org/10.1039/c2jm33058j

Abstract

Strontium has been substituted for calcium in the glass series (SiO2)49.46(Na2O)26.38(P2O5)1.07 (CaO)23.08−x(SrO)x (where x = 0, 11.54, 23.08) to elucidate their underlying atomic-scale structural characteristics as a basis for understanding features related to the bioactivity. These bioactive glasses have been investigated using isomorphic neutron and X-ray diffraction, Sr K-edge EXAFS and solid state 17O, 23Na, 29Si, 31P and 43Ca magic-angle-spinning (MAS) NMR. An effective isomorphic substitution first-order difference function has been applied to the neutron diffraction data, confirming that Ca and Sr behave in a similar manner within the glass network, with residual differences attributed to solely the variation in ionic radius between the two species. The diffraction data provides the first direct experimental evidence of split Ca–O nearest-neighbour correlations in these melt-quench bioactive glasses, together with an analogous splitting of the Sr–O correlations; the correlations are attributed to the metal ions correlated either to bridging or to non-bridging oxygen atoms. Triple quantum (3Q) 43Ca MAS NMR corroborates the split Ca–O correlations. Successful simplification of the 2 < r (Å) < 3 region via the difference method has also revealed two distinct Na environments. These environments are attributed to sodium correlated either to bridging or to non-bridging oxygen atoms. Complementary multinuclear MAS NMR, Sr K-edge EXAFS and X-ray diffraction data supports the structural model presented. The structural sites present will be intimately related to their release properties in physiological fluids such as plasma and saliva, and hence the bioactivity of the material. Detailed structural knowledge is therefore a prerequisite for optimising material design.

Item Type: Article
DOI/Identification number: 10.1039/c2jm33058j
Additional information: Unmapped bibliographic data: LA - English [Field not mapped to EPrints] J2 - J. Mater. Chem. [Field not mapped to EPrints] AD - School of Physical Sciences, University of Kent, Canterbury Kent CT2 7NH, United Kingdom [Field not mapped to EPrints] AD - School of Engineering and Applied Science, Aston Research Centre for Healthy Ageing, Aston University, Birmingham B4 7ET, United Kingdom [Field not mapped to EPrints] AD - Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom [Field not mapped to EPrints] AD - Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD, United Kingdom [Field not mapped to EPrints] AD - Institute of Dentistry, Queen Mary University of London, London E1 4NS, United Kingdom [Field not mapped to EPrints] AD - Diamond Light Source, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0DE, United Kingdom [Field not mapped to EPrints] AD - CEA, IRAMIS, CNRS 3299, F-91191 Gif-sur-Yvette cedex, France [Field not mapped to EPrints] DB - Scopus [Field not mapped to EPrints]
Uncontrolled keywords: Atomic scale, Difference functions, Difference method, Diffraction data, EXAFS, Experimental evidence, First-order, Glass network, Ionic radius, Isomorphic substitution, MAS NMR, Material designs, Melt-quench, Multinuclear solid state NMR, Nearest-neighbour, Neutron diffraction data, Non-bridging oxygen atoms, Physiological fluids, Release property, Site distribution, Structural characteristics, Structural knowledge, Structural models, Triple quantum, X-ray diffraction data, Atoms, Bioactive glass, Crystal atomic structure, Magic angle spinning, Metal ions, Model structures, Neutron diffraction, Oxygen, Sodium, Strontium, X ray diffraction, Calcium
Subjects: Q Science > QC Physics > QC173.45 Condensed Matter
Q Science > QD Chemistry > QD478 Solid State Chemistry
Divisions: Faculties > Sciences > School of Physical Sciences
Faculties > Sciences > School of Physical Sciences > Functional Materials Group
Depositing User: Giles Tarver
Date Deposited: 12 Feb 2015 11:42 UTC
Last Modified: 29 May 2019 14:09 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/46956 (The current URI for this page, for reference purposes)
Newport, Robert J.: https://orcid.org/0000-0002-2365-992X
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