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时影响是微细颗粒在液体表面运动的主要现象。通过分子动力学模拟和可视化实验研究了这些情况下的接触线行为。得到了以下结果。首先，当阶梯高度小于流体-流体界面厚度时，阶梯处接触线的钉扎效应减小。第二，当固体表面作阶跃运动时，即使对于微观的(~nm)动态接触角，接触线速度对接触角的瞬时影响也不可忽略。这种瞬变效应也在宏观(Mm)实验中观察到。

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.