Molecular dynamics simulation was used to simulate the wetting of water droplets on surfaces patterned with different texture structures. Through the study of texture structures with different rough elements, we find that the wettability is closely related to the texture structure, and the molecular dynamics contact angles of different wetting modes are in good agreement with the predicted value by the Cassie-Baxter equation, in which the influence of gravity is negligible. In order to investigate this phenomenon in detail, we analyzed the wetting states, contact angles, density distributions of droplets on different surfaces, radial distribution functions of different hydration layers, grid distribution of hydrogen bonds and density of hydrogen bonds. The results showed the arrangement of water molecules in the first hydration layer and the distributions of hydrogen bond grid have a substantial impact on wettability of rough surfaces. The influence mechanism of the surface structure on the wettability is explained from the atomic level. Meanwhile, the consistency between molecular dynamics simulation and Cassie-Baxter equation show that the contact angles increase with the decrease of solid surface area fraction even if the surface texture structures are different.

使用分子动力学模拟来模拟在具有不同纹理结构的表面上水滴的润湿。通过研究具有不同粗糙元素的纹理结构，我们发现润湿性与纹理结构密切相关，并且不同润湿方式的分子动力学接触角与Cassie-Baxter方程的预测值吻合良好。重力的影响可以忽略不计。为了详细研究这种现象，我们分析了润湿状态，接触角，液滴在不同表面上的密度分布，不同水化层的径向分布函数，氢键的网格分布以及氢键的密度。结果表明，第一水化层中水分子的排列方式和氢键网格的分布对粗糙表面的润湿性有很大影响。从原子水平解释了表面结构对润湿性的影响机理。同时，分子动力学模拟与Cassie-Baxter方程之间的一致性表明，即使表面纹理结构不同，接触角也会随着固体表面积分数的减小而增加。