正癸烷纳米液滴润湿特性的分子动力学研究

流体液滴在固体表面的浸润性对其润滑性能至关重要.本文利用分子动力学方法研究了正癸烷纳米液滴在铜表面上的润湿特性.结果表明：在平坦光滑表面上，壁面的厚度和分子数目对润湿效果影响不大.随着壁面能量势阱参数εs 增大，接触角线性减小.随着温度升高，液滴的接触角减小.在沟槽粗糙表面上，随着粗糙度因子增大，对于疏液表面，接触角增大到一定值后基本保持不变，符合Cassie理论；中性和亲液表面接触角则会减小，为Wenzel润湿模式.当表面分数增大时，疏液与亲液表面接触角整体呈减小的趋势，对中性表面影响不大.当温度升高时，粗糙疏液表面接触角会增大，润湿效果更差，而粗糙中性和亲液表面液滴润湿性会更好.

Molecular dynamics study on the wetting characteristics of n-decane nano-droplets

The wettability of fluid droplets on the solid surface is critical to its lubricating property.In this work, molecular dynamics methods are used to study the wetting characteristics of n-decane nanodroplets on copper surfaces. The results show that on a flat and smooth surface, the thickness of the wall and the number of molecules have little effect on the wetting effect. As the wall energy potential parameter increases, the contact angle decreases linearly. As the temperature increases, the contact angle of the droplets decreases overall. On the groove rough surface, as the roughness factor increases, the contact angle remains basically unchanged after increasing to a certain value, which conforms to the Cassie theory for the lyophobic surface; the contact angle of neutral and lyophilic surfaces will decrease, and the wetting will be Wenzel mode. When the surface fraction increases, the overall contact angle of the lyophobic and lyophilic surfaces shows a decreasing trend, which has little effect on the neutral surface. As the temperature increases, the contact angle of the rough lyophobic surface will increase and the wetting effect will be worse, while the wettability of the rough neutral and lyophilic surface droplets will be better.