Crystallization of CaCO3 in Water-Alcohol Mixtures: Spherulitic Growth, Polymorph Stabilization, and Morphology Change
Crystallization of CaCO3 in Water-Alcohol Mixtures: Spherulitic Growth, Polymorph Stabilization, and Morphology Change
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DOI：
10.1021/cg2012342
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发表时间：
2012-02-01
影响因子：
3.8
通讯作者：
Stipp, S. L. S.
中科院分区：
文献类型：
--
作者：
Sand, K. K.;Rodriguez-Blanco, J. D.;Stipp, S. L. S.
二元醇水混合物中醇的存在会影响无水结晶CaCO 3多晶型物的沉淀途径及其形态。我们探讨了方解石，球霰石，文石的形成途径和几个参数的影响：简单的醇，时间和摇动速度的浓度，我们推导出一个多参数模型预测相是首选。我们发现，振荡速度和酒精浓度是影响球文石和文石的稳定性和改变球文石形态，从菜花形，球形聚集体，树枝状，扁平结构的最重要的参数。在我们所有的实验中，沉淀的文石是孪生的，球文石和文石都可以解释为通过球晶生长形成。经典生长理论充分描述了它们的形成;没有必要援引流行的假设，即纳米晶体通过自组装进行非经典生长。这些研究以及未来低水活度溶液的研究，为更好地了解生物体如何选择其首选的多晶型物和生物矿化过程中工程师CaCO 3形态铺平了道路。
The presence of alcohol in binary alcohol water mixtures can affect the precipitation pathways of anhydrous crystalline CaCO3 polymorphs and their morphology. We explored the formation pathways and the effects of several parameters on calcite, vaterite, and aragonite: concentration of simple alcohols, time, and shaking speed, and we derived a multiparameter model for predicting what phase is preferred. We found that shaking speed and alcohol concentration are the most important parameters for affecting the stability of vaterite and aragonite and for changing vaterite morphology, from cauliflower-shaped, spherical aggregates, to dendritic, flatter structures. In all our experiments, the precipitated aragonite was twinned, and both the vaterite and aragonite can be interpreted to form through spherulitic growth. Classical growth theory fully describes their formation; there is no need to invoke the popular hypothesis for nonclassical growth by self-assembly of nanocrystals. These studies, and future work with solutions of low water activity, are paving the way to a better understanding of how organisms select their preferred polymorph and engineer CaCO3 morphology during biomineralization.