Molecular Dynamics Simulation of Channel Size Dependence of the Friction Coefficient between a Water Droplet and a Nanochannel Wall
Molecular Dynamics Simulation of Channel Size Dependence of the Friction Coefficient between a Water Droplet and a Nanochannel Wall
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DOI：
10.1021/acs.jpcc.5b07951
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发表时间：
2015-12
影响因子：
3.7
通讯作者：
A. Fukushima;Toshiki Mima;I. Kinefuchi;T. Tokumasu
中科院分区：
文献类型：
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作者：
A. Fukushima;Toshiki Mima;I. Kinefuchi;T. Tokumasu
微/纳机电系统的快速发展需要对纳米结构中的流体学有详细的了解。在本文中，水滴在纳米通道中的动力学分析使用分子动力学模拟。随着通道尺寸的减小，液滴和固体壁之间的剪切应力变得比基于常规滑移边界条件的预测大得多。我们的分析表明，Navier摩擦系数是相当敏感的液体压力，这往往是显着大的疏水纳米通道，因为拉普拉斯压力。我们提出了一个修改后的版本的杨拉普拉斯方程，可以准确地估计在纳米通道中的液体压力。通过考虑这些纳米通道的特性，我们已经成功地推导出一个表达式，描述了液滴和固体壁之间的剪切应力的通道尺寸依赖性。
The rapid spread of micro/nanoelectromechanical systems necessitates detailed understanding of fluidics within nanoscale structures. In this paper, the dynamics of a water droplet in nanochannels are analyzed using molecular dynamics simulations. As the channel size decreases, the shear stress between the droplet and the solid wall becomes much larger than predictions based on conventional slip boundary conditions. Our analysis shows that the Navier friction coefficient is quite sensitive to liquid pressure, which tends to be significantly large in hydrophobic nanochannels because of the Laplace pressure. We propose a modified version of the Young–Laplace equation that can accurately estimate the liquid pressure in nanochannels. By accounting for these nanochannel characteristics, we have successfully derived an expression that describes the channel size dependence of the shear stress between the droplet and the solid wall.