UCL  IRIS
Institutional Research Information Service
UCL Logo
Please report any queries concerning the funding data shown on the profile page to:

http://www.ucl.ac.uk/finance/secure/research/post_award
Please report any queries concerning the student data shown on the profile page to:

Email: portico-services@ucl.ac.uk

Help Desk: http://www.ucl.ac.uk/ras/portico/helpdesk
Publication Detail
Fluorine environment in bioactive glasses: ab initio molecular dynamics simulations.
  • Publication Type:
    Journal article
  • Publication Sub Type:
    Journal Article
  • Authors:
    Christie JK, Pedone A, Menziani MC, Tilocca A
  • Publication date:
    10/03/2011
  • Pagination:
    2038, 2045
  • Journal:
    J Phys Chem B
  • Volume:
    115
  • Issue:
    9
  • Country:
    United States
  • Language:
    eng
  • Keywords:
    Anti-Bacterial Agents, Calcium, Fluorine, Glass, Molecular Conformation, Molecular Dynamics Simulation, Oxygen, Silicates, Silicon, Sodium, Temperature
Abstract
Fluorinated bioactive glasses (FBGs) combine the antibacterial properties of fluorine with the biological activity of phosphosilicate glasses. Because their biomedical application depends on the release of fluorine, the detailed characterization of the fluorine environment in FBGs is the key to understand their properties. Car-Parrinello molecular dynamics (CPMD) simulations have been performed on a 45S5 Bioglass composition in which 10 mol % of the CaO has been replaced with CaF(2), and have allowed us to resolve some longstanding issues about the atomic structure of fluorinated bioglasses, with particular regard to the structural role of fluorine. F is coordinated almost entirely to the modifier ions Na and Ca, with a very small amount of residual Si-F bonds, whose fraction only becomes significant in the melt precursor. High temperature leads to Si-F bonds in both tetra- (SiO(3)F) and, less frequently, penta-coordinated (SiO(4)F and SiO(3)F(2)) complexes, showing that formation of these bonds through the expansion of the SiO(4) coordination shell is generally less favored. There is no evidence for preferential bonding of F to either modifier ion: almost all F atoms are coordinated to both calcium and sodium in a "mixed state", rather than exclusively to either, as had been conjectured. We discuss the consequences of these findings on the properties of fluorine-containing bioglasses.
Publication data is maintained in RPS. Visit https://rps.ucl.ac.uk
 More search options
UCL Authors
University College London - Gower Street - London - WC1E 6BT Tel:+44 (0)20 7679 2000

© UCL 1999–2011

Search by