Stability-limited ion-exchange of calcium with zinc in biomimetic hydroxyapatite

Materials & Design

Arno van der Weijden¹  Willem L. Noorduin¹  Gijsbertus de With²  Sjoerd W. Nooteboom²  Mark M.J. van Rijt² 

[1] AMOLF, 1098 XG Amsterdam, The Netherlands;Laboratory of Physical Chemistry, Centre for Multiscale Electron Microscopy, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands;

关键词: Ion-exchange;    Hydroxyapatite;    HAp;    Calcium;    Zinc;   

DOI  :  

来源: DOAJ

【 摘 要 】

The exchange of Ca2+ ions in hydroxyapatite (HAp) with Zn2+ ions into Zn-HAp is of interest for applications ranging from bone tissue engineering to the use as a precursor in subsequent ion-exchange reactions. Previous studies, using direct synthesis, showed that ~ 20 mol% Zn2+ ions can be incorporated into HAp, before byproducts are observed. However, this is realized at the cost of a loss in crystallinity and control over crystal size and shape with increasing amounts of Zn2+ ion incorporation. In this work a simple post-synthetic ion-exchange strategy for the formation of Zn-HAp has been investigated. By merely exposing HAp to high concentrations of zinc nitrate in water, up to 22 mol% of the Ca2+ ions can displaced by Zn2+ ions without any measured loss in crystallinity and preservation of crystallite size and shape. It was found that the incorporation of Zn2+ ions destabilizes the HAp crystals resulting in their gradual dissolution and reprecipitation. Consequently, promoting the exchange of Ca2+ with Zn2+ions using increased reaction times, sonication and increased temperature results in an increased dissolution of HAp and precipitation of hopeite crystals, thereby preventing the formation of more zinc rich Zn-HAp.

【 授权许可】

Unknown