Effectiveness of the Young-Laplace equation at nanoscale.
Effectiveness of the Young-Laplace equation at nanoscale.
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DOI：
10.1038/srep23936
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发表时间：
2016-04-01
影响因子：
4.6
通讯作者：
Cao G
中科院分区：
文献类型：
--
作者：
Liu H;Cao G
利用分子动力学（MD）模拟方法，提出了一种基于加压水从平板纳米孔（1.3-2.7 nm）中流出的行为的新方法，计算了水面曲率与水面压差之间的关系.研究发现，在纳米尺度下，水表面曲率与表面压差成反比，这种关系适用于不同孔径、温度甚至电解质溶液。在此基础上，我们不仅可以有效地确定水的表面张力以及温度和电解质离子对表面张力的影响，而且还证明了Young-Laplace（Y-L）方程在纳米尺度下的有效性。此外，水与亲水性材料的接触角可以通过水表面的临界不稳定压力（爆裂压力）与纳米孔尺寸之间的关系进一步计算。结合水在疏水微通道中的渗透行为，通过测量引起水表面不稳定的临界压力，可以更准确地确定纳米尺度下水的接触角，大大降低了纳米尺度下水接触角测量的不确定度。
Using molecular dynamics (MD) simulations, a new approach based on the behavior of pressurized water out of a nanopore (1.3–2.7 nm) in a flat plate is developed to calculate the relationship between the water surface curvature and the pressure difference across water surface. It is found that the water surface curvature is inversely proportional to the pressure difference across surface at nanoscale, and this relationship will be effective for different pore size, temperature, and even for electrolyte solutions. Based on the present results, we cannot only effectively determine the surface tension of water and the effects of temperature or electrolyte ions on the surface tension, but also show that the Young-Laplace (Y-L) equation is valid at nanoscale. In addition, the contact angle of water with the hydrophilic material can be further calculated by the relationship between the critical instable pressure of water surface (burst pressure) and nanopore size. Combining with the infiltration behavior of water into hydrophobic microchannels, the contact angle of water at nanoscale can be more accurately determined by measuring the critical pressure causing the instability of water surface, based on which the uncertainty of measuring the contact angle of water at nanoscale is highly reduced.