论文标题
接触线动力学中的状态和速率摩擦
State-and-rate friction in contact-line dynamics
论文作者
论文摘要
为了探测接触线运动的动力学，我们研究了沉积在精心准备的水平表面上的无柄滴的宏观特性。通过在液滴去除过程中同时测量接触角和滴宽度，我们确定滴剂的形状变化在滴剂上和退缩时。我们的数据表明，有一支反对接触线运动的力，这两者都取决于降落与表面接触的时间和撤回率。对于硅烷化玻璃上的水，我们使用过度阻尼的接触线运动模型捕获了实验观察到的行为，其中现象学阻力系数和假定的平衡接触角是唯一的输入。对于其他液体/底物对，观察到的接触线运动表明，除阻尼外，最大的静态摩擦力很重要。在三个底物 - 液体对中，对接触时间和撤回率的时间的依赖性在固体表面之间的速率和状态摩擦在质量上是一致的。
In order to probe the dynamics of contact-line motion, we study the macroscopic properties of sessile drops deposited on and then aspirated from carefully prepared horizontal surfaces. By measuring the contact angle and drop width simultaneously during droplet removal, we determine the changes in the shape of the drop as it depins and recedes. Our data indicate that there is a force which opposes the motion of the contact line that depends both on the amount of time that the drop has been in contact with the surface and on the withdrawal rate. For water on silanized glass, we capture the experimentally observed behavior with an overdamped dynamical model of contact-line motion in which the phenomenological drag coefficient and the assumed equilibrium contact angle are the only inputs. For other liquid/substrate pairs, the observed contact-line motion suggests that a maximum static friction force is important in addition to damping. The dependence on time of contact and withdrawal rate, reminiscent of rate-and-state friction between solid surfaces, is qualitatively consistent across three substrate-liquid pairs.
