Interfacial Concentration Effect Facilitates Heterogeneous Nucleation from Solution
Interfacial Concentration Effect Facilitates Heterogeneous Nucleation from Solution
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DOI：
10.1021/acs.jpclett.0c00540
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发表时间：
2020-03-19
影响因子：
5.7
通讯作者：
Johnston, Karen
中科院分区：
文献类型：
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作者：
McKechnie, David;Anker, Samira;Johnston, Karen
溶液中的晶体成核在环境、生物和工业过程中发挥着重要作用，并且主要发生在界面处，尽管其机制尚不清楚。我们对甘氨酸水溶液进行了成核实验，发现与空气-溶液界面相比，油-溶液界面显着加速了甘氨酸成核。这是令人惊讶的，因为预计非极性疏水油（十三烷）不会有利于高极性亲水甘氨酸的异相成核。分子动力学模拟发现，油-溶液和空气-溶液界面处的甘氨酸浓度分别显着提高和耗尽。我们认为这种界面浓度效应促进了异质成核，并且这是由于色散相互作用造成的。这种界面效应与之前描述的机制不同，包括表面功能化、模板化和限制，预计将出现在广泛的解决方案系统中。这项工作提供了对于理解和控制异质成核至关重要的新见解。
Crystal nucleation from solution plays an important role in environmental, biological, and industrial processes and mainly occurs at interfaces, although the mechanisms are not well understood. We performed nucleation experiments on glycine aqueous solutions and found that an oil-solution interface dramatically accelerates glycine nucleation compared to an air-solution interface. This is surprising given that nonpolar, hydrophobic oil (tridecane) would not be expected to favor heterogeneous nucleation of highly polar, hydrophilic glycine. Molecular dynamics simulations found significantly enhanced vs depleted glycine concentrations at the oil-solution vs air-solution interfaces, respectively. We propose that this interfacial concentration effect facilitates heterogeneous nucleation, and that it is due to dispersion interactions. This interface effect is distinct from previously described mechanisms, including surface functionalization, templating, and confinement and is expected to be present in a wide range of solution systems. This work provides new insight that is essential for understanding and controlling heterogeneous nucleation.