Water evaporation: a transition path sampling study.
Water evaporation: a transition path sampling study.
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DOI：
10.1021/jp310070y
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发表时间：
2012-10
期刊：
影响因子：
--
通讯作者：
P. Varilly;D. Chandler
中科院分区：
文献类型：
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作者：
P. Varilly;D. Chandler
在SPC/E模式中，我们采用过渡路径取样来研究液态水的蒸发。在数千个蒸发轨迹的基础上，我们表征了过渡态系综（TSE）的成员，其表现出在蒸发位点具有主要为负平均曲率的液-汽界面。我们还发现，蒸发完成后，平移和角动量分布的蒸发水是麦克斯韦与液体的温度相等。为了描述蒸发轨迹的整体特征，我们发现将它们投影到两个坐标上就足够了：蒸发分子到瞬时液-气界面的距离和水沿着平均界面法线的速度。在这个预计的空间中，我们发现，TSE是很好地捕获的一个简单的模型的弹道逃逸深势阱，没有额外的障碍，蒸发超过凝聚力的液体。同样地，它们与水分子撞击液滴冷凝的接近1的概率一致。这些结果与以前的模拟和一些，但不是全部，最近的实验。
We use transition path sampling to study evaporation in the SPC/E model of liquid water. On the basis of thousands of evaporation trajectories, we characterize the members of the transition state ensemble (TSE), which exhibit a liquid-vapor interface with predominantly negative mean curvature at the site of evaporation. We also find that after evaporation is complete, the distributions of translational and angular momenta of the evaporated water are Maxwellian with a temperature equal to that of the liquid. To characterize the evaporation trajectories in their entirety, we find that it suffices to project them onto just two coordinates: the distance of the evaporating molecule to the instantaneous liquid-vapor interface and the velocity of the water along the average interface normal. In this projected space, we find that the TSE is well-captured by a simple model of ballistic escape from a deep potential well, with no additional barrier to evaporation beyond the cohesive strength of the liquid. Equivalently, they are consistent with a near-unity probability for a water molecule impinging upon a liquid droplet to condense. These results agree with previous simulations and with some, but not all, recent experiments.