The Stabilizing Effect of Silicate on Biogenic and Synthetic Amorphous Calcium Carbonate

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• 作者：Assaf Gal ; Steve Weiner ; Lia Addadi
• 刊名：Journal of the American Chemical Society
• 出版年：2010
• 出版时间：September 29, 2010
• 年：2010
• 卷：132
• 期：38
• 页码：13208-13211
• 全文大小：300K
• 年卷期：v.132,no.38(September 29, 2010)
• ISSN：1520-5126

文摘

Silicate ions increase the thermal stability of the unstable amorphous calcium carbonate (ACC). This effect was observed first by comparing ACC from two different species of cystoliths, small calcified bodies formed in the leaves of some plants. The temperature of crystallization to calcite in the silicate-rich cystoliths from M. alba is 100 °C higher than that of the silicate-poor cystoliths from F. microcarpa. The stabilizing effect is confirmed in vitro with synthetic samples differing in their silicate content. With increasing silicate concentration in ACC, the crystallization temperature to calcite also increases. A mechanism of geometric frustration is suggested, whereby the presence of the tetrahedral silicate ion in the flat carbonate lattice prevents organization into crystalline polymorphs.