Controlled synthesis of calcium carbonate nanocrystals with multi-morphologies in different bicontinuous microemulsions

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• 作者：Yuhua Shen ; Anjian Xie ; Zhangxu Chen ; Wanghua Xu ; Hui Yao ; Shikuo Li ; Lachun Huang ; Zhifu Wu ; Xiangyun Kong
• 关键词：Bicontinuous microemulsion ; Calcium carbonate nanocrystal ; Controlled synthesis ; dl-Asp ; Biomineralization
• 刊名：Materials Science and Engineering: A
• 出版年：2007
• 出版时间：15 January 2007
• 年：2007
• 卷：443
• 期：1-2
• 页码：95-100
• 全文大小：681 K

文摘

The nucleation and growth of calcium carbonate nanocrystals were studied in two types of bicontinuous microemulsions, consisted of P-octyl polyethylene glycol phenylether (OP)/n-amyl alcohol/cyclohexane/water, and the above microemulsion containing dl-aspartic acid (dl-Asp). The produced CaCO₃ nanocrystals were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectrometer (FT-IR) and X-ray diffraction (XRD). The results indicated that OP and dl-Asp used as soft template could control synthesis of CaCO₃ nanocrystals well. The various shapes of CaCO₃ nanocrystals, such as solid sphere, network, whisker, rod, and hollow sphere were successfully prepared by altering the concentration of the reactants, adding dl-Asp, and adjusting the pH values of dl-Asp/CaCl₂ aqueous solution. Sole calcite phase was obtained in OP bicontinuous microemulsion. The presence of dl-Asp was helpful for the formation of thermodynamically unstable vaterite phase. In OP/dl-Asp bicontinuous microemulsion, the higher pH value of dl-Asp/CaCl₂ aqueous solution is, the more vaterite will be formed. A nucleation-limited growth and limited aggregation (NGA) model was used to explain growth mechanism of the network-like calcium carbonate in this study.