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arXiv 0909.4097cond-mat.stat-mech
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水在扩展的疏水和亲水表面附近的波动

Fluctuations of water near extended hydrophobic and hydrophilic surfaces

Amish J. Patel, David Chandler

摘要:

我们使用分子动力学模拟的SPC-E模型的液态水,以获得不同形状和大小的探针体积中的水密度波动的概率分布,无论是在散装以及近疏水和亲水表面。为了获得我们的结果,我们引入了一个有偏见的粗粒度的密度,这反过来又偏见的实际溶剂密度的采样。该技术很容易与分子动力学积分算法相结合。我们的主要结果是,疏水性表面附近的水的密度波动的概率,有或没有表面水的吸引力,类似于在水蒸气界面的密度波动。具体而言,密度耗尽的概率在表面附近是显着大于在体。相比之下,我们发现,模型亲水表面附近的水密度波动的统计是类似的散装。

英文摘要:

We use molecular dynamics simulations of the SPC-E model of liquid water to derive probability distributions for water density fluctuations in probe volumes of different shapes and sizes, both in the bulk as well as near hydrophobic and hydrophilic surfaces. To obtain our results, we introduce a biased sampling of coarse-grained densities, which in turn biases the actual solvent density. The technique is easily combined with molecular dynamics integration algorithms. Our principal result is that the probability for density fluctuations of water near a hydrophobic surface, with or without surface-water attractions, is akin to density fluctuations at the water-vapor interface. Specifically, the probability of density depletion near the surface is significantly larger than that in bulk. In contrast, we find that the statistics of water density fluctuations near a model hydrophilic surface are similar to that in the bulk.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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