Motion of Spherical Micro-particles on Liquid Interface-Elucidation in Terms of Microscopic Dynamic Wetting

粗糙表面上的接触线行为和接触线速度对动态接触角的瞬态影响是微小颗粒在液体表面上运动的主要现象。分子动力学模拟和可视化实验进行了调查在这些情况下的接触线行为。获得了以下结果。首先，当台阶高度小于流体-流体界面厚度时，台阶处接触线的钉扎效应减小。第二，接触线速度对接触角的瞬时影响是不可忽略的小，即使是微观（~nm）的动态接触角时，固体表面的台阶状运动。在宏观（mm）实验中也观察到这种瞬态效应。

The contact line behavior on rough surface and the transient effect of the contact line velocity on the dynamic contact angle are dominant phenomena for the motion of micro particle on the liquid surface. Molecular dynamics simulations and visualization experiments were performed to investigate the contact line behavior in these situations. The following results were obtained. First, the pinned effect of contact line at a step is reduced when the height of the step is less than the thickness of fluid-fluid interface. Second, the transient effect of the contact line velocity on the contact angle is not negligibly small even for the microscopic (~nm) dynamic contact angle when the step-like motion of the solid surface. Such transient effect also was also observed in the macroscopic (mm) experiment.