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Synthesis, characterization and modelling of zinc and silicate co-substituted hydroxyapatite.

Friederichs RJ, Chappell HF, Shepherd DV, Best SM - J R Soc Interface (2015)

Bottom Line: Zn and silicate insertion into HA was modelled using density functional theory (DFT).Different scenarios were considered where Zn substituted for different calcium sites or at a 2b site along the c-axis, which was suspected in singly substituted ZnHA.The most energetically favourable site in ZnSiHA was Zn positioned at a previously unreported interstitial site just off the c-axis near a silicate tetrahedron sitting on a phosphate site.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, UK robert.friederichs@gmail.com.

No MeSH data available.


Related in: MedlinePlus

Lattice parameters with respect to silicon amount as measured by XRF.
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RSIF20150190F2: Lattice parameters with respect to silicon amount as measured by XRF.

Mentions: The lattice parameters of ZnSiHA differed from HA, singly substituted ZnHA and SiHA, suggesting co-substitution (table 2). Plots of a and c parameters with respect to Zn and Si amount are shown in figure 2. In the case of SiHA, the a parameter contracted and the c parameter expanded compared with HA, which was similar to the trends observed by Gibson et al. [12], who also used a wet chemical precipitation method. The c parameter typically increases with Si substitution given the relatively larger ionic radius of Si compared with P, and relative charge difference of silicate on the phosphate site [40]. The a parameter and unit cell volumes were found to vary widely in the literature. This variation in the a parameter is likely due to the many different synthesis methods and subsequent heat treatment environments used in making SiHA. Marchat et al. suggested that the a parameter variation in SiHA likely results from OHA (oxyhydroxyapatite) formation, which was shown to slightly reduce the a parameter length [14,41].TableĀ 2.


Synthesis, characterization and modelling of zinc and silicate co-substituted hydroxyapatite.

Friederichs RJ, Chappell HF, Shepherd DV, Best SM - J R Soc Interface (2015)

Lattice parameters with respect to silicon amount as measured by XRF.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4528584&req=5

RSIF20150190F2: Lattice parameters with respect to silicon amount as measured by XRF.
Mentions: The lattice parameters of ZnSiHA differed from HA, singly substituted ZnHA and SiHA, suggesting co-substitution (table 2). Plots of a and c parameters with respect to Zn and Si amount are shown in figure 2. In the case of SiHA, the a parameter contracted and the c parameter expanded compared with HA, which was similar to the trends observed by Gibson et al. [12], who also used a wet chemical precipitation method. The c parameter typically increases with Si substitution given the relatively larger ionic radius of Si compared with P, and relative charge difference of silicate on the phosphate site [40]. The a parameter and unit cell volumes were found to vary widely in the literature. This variation in the a parameter is likely due to the many different synthesis methods and subsequent heat treatment environments used in making SiHA. Marchat et al. suggested that the a parameter variation in SiHA likely results from OHA (oxyhydroxyapatite) formation, which was shown to slightly reduce the a parameter length [14,41].TableĀ 2.

Bottom Line: Zn and silicate insertion into HA was modelled using density functional theory (DFT).Different scenarios were considered where Zn substituted for different calcium sites or at a 2b site along the c-axis, which was suspected in singly substituted ZnHA.The most energetically favourable site in ZnSiHA was Zn positioned at a previously unreported interstitial site just off the c-axis near a silicate tetrahedron sitting on a phosphate site.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, UK robert.friederichs@gmail.com.

No MeSH data available.


Related in: MedlinePlus