Accurate estimation of surface wettability for various degrees of hydrophobicity becomes increasingly important in the molecular design of membrane. In this paper, we develop simple yet physically realistic model for estimating contact angle via hybridizing molecular dynamics and pseudocontinuum theory. Molecular dynamics simulations were carried out to compute the macro-scale contact angle between a water droplet and smooth walls from the nanoscale calculations. A macro-level droplet including countless degrees of freedom due to an infinite number of molecules is impossible to be studied directly via atomistic simulations. To resolve this issue, we employed two approaches consisting of the pseudocontinuum approximation and the modified Young-Laplace equation. The former involves the 9-3 Lennard-Jones (L-J) potential and can drastically reduce the degrees of freedom in molecular simulations, while the latter relates the mesoscale contact angle to the realistic one. We altered different parameters including the liquid-surface potential characteristics and the temperature, and calculated the water contact angle by leveraging the mass density profile fitting method to predict the broad spectrum of hydrophobic and hydrophilic substrates. The computational results were compared with the experimental data for various materials including graphite, silicon, and metals. This study suggests that pseudocontinuum modeling is an accurate approach to probe surface wettability for various processes at a low computational cost.
Contact lines on stretched soft solids: Modeling anisotropic surface stresses
我们提出了由于大液滴的静态润湿而导致的拉伸软基底变形的完全解析解，并将我们的解决方案与最近发表的实验进行了比较（Xu et al，软物质2018）。格林函数的方法之后，我们扩展了表面应力正则化的Flamant-Cerruti问题，占单轴预应变的基板。提供了线性化和有限运动学的表面轮廓，包括湿润脊的高度和开口角度。我们适合实验润湿脊形状作为施加应变的函数，使用两个自由参数，表面拉梅系数。在与实验相比，我们发现，观察到的开度角更准确地捕捉使用有限的运动学，特别是随着施加的预应变水平的增加。这些拟合定性地与Xu等人的结果一致，但修正了表面弹性常数的值。
Electrowetting-Controlled Dropwise Condensation with Patterned Electrodes: Physical Principles, Modeling, and Application Perspectives for Fog Harvesting and Enhanced Heat Transfer
