Evidence that crystal nucleation in aqueous NaCl solution Occurs by the two-step mechanism
Evidence that crystal nucleation in aqueous NaCl solution Occurs by the two-step mechanism
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DOI：
10.1016/j.cplett.2013.09.054
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发表时间：
2013-11-05
影响因子：
2.8
通讯作者：
Patey, G. N.
中科院分区：
文献类型：
--
作者：
Chakraborty, Debashree;Patey, G. N.
采用分子动力学模拟方法研究了NaCl溶液中晶体的成核机理。我们的观察支持一个两步机制，类似于最近提出的其他系统[P.G. Vekilov，Nanoscale 2（2010）2346]。这两个连续的步骤包括浓度波动，导致密集的离子“补丁”，然后是空间排序。第二，空间排序步骤是速率决定，与一些蛋白质解决方案一致。临界NaCl核的“尺寸”类似于1 nm，包括类似于环境温度下的75个离子。鉴于两步机制的证据被发现为不同的溶质NaCl和蛋白质，它似乎是一个重要的机制，均匀的晶体成核。(C)2013年爱思唯尔B。V.保留所有权利。
Molecular dynamics simulations are used to investigate the mechanism of crystal nucleation in NaCl solution. Our observations support a two-step mechanism, similar to that recently proposed for other systems [P.G. Vekilov, Nanoscale 2 (2010) 2346]. The two sequential steps consist of a concentration fluctuation resulting in a dense ion "patch'' followed by spatial ordering. The second, spatial-ordering step is rate determining, consistent with some protein solutions. The "size'' of the critical NaCl nucleus is similar to 1 nm, including similar to 75 ions at ambient temperatures. Given that evidence for the two-step mechanism is found for solutes as different as NaCl and proteins, it appears to be an important mechanism of homogeneous crystal nucleation. (C) 2013 Elsevier B. V. All rights reserved.