ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Silicate substituted hydroxyapatite bioceramics have been shown to enhance bone repair invivo compared to hydroxyapatite (HA), although the amount of silicate ions that can be substitutedalone into the hydroxyapatite structure is limited to approximately 5.2 wt%, or 1.6 wt% Si. This studydescribes the substitution of greater levels of silicate ions via co-substitution of silicate ions withtrivalent yttrium ions, without resulting in the formation of any secondary phases. This substitutionmechanism involves a coupled substitution of yttrium and silicate ions for calcium and phosphateions, respectively, and enables a level of silicate substitution up to approximately 9 wt%. Twodifferent substitution mechanisms result in subtle differences in the crystal structure. When themechanism xY3+ + xSiO44- was used, a small decrease in the a-axis, but no change in the c-axis, of theunit cell compared to HA was observed. In contrast, when the mechanism x/2Y3+ + xSiO44- was used,a significant increase in the c-axis of the unit cell was observed, compared to HA. XRF analysis andFTIR spectroscopy supported the proposed substitution mechanisms. These novel substitutionmechanisms not only enable greater levels of silicate-substitution in HA to be prepared, but also allowthe production of compositions with the same level of silicate substitution, and with subtle differencesin chemical structure
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/52/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.330-332.87.pdf
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