Guan Dongshi, Charlaix Elisabeth, Tong Penger
State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China.
Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
Phys Rev Lett. 2020 May 8;124(18):188003. doi: 10.1103/PhysRevLett.124.188003.
We report direct atomic-force-microscope measurements of capillary force hysteresis (CFH) of a circular contact line (CL) formed on a long glass fiber, which is coated with a thin layer of soft polymer film and intersects a water-air interface. The measured CFH shows a distinct overshoot for the depinning of a static CL, and the overshoot amplitude grows logarithmically with both the hold time τ and fiber speed V. A unified model based on the slow growth of a wetting ridge and force-assisted barrier crossing is developed to explain the observed time (or state) and speed (or rate) dependent CL depinning dynamics over an aging soft surface. The experimental findings have important implications to a common class of problems involving depinning dynamics in a defect or roughness landscape, such as friction of solid interfaces.
我们报告了对在长玻璃纤维上形成的圆形接触线（CL）的毛细力滞后（CFH）进行的直接原子力显微镜测量，该玻璃纤维涂有一层薄的软聚合物薄膜，并与水 - 空气界面相交。测量得到的CFH显示出静态CL脱钉时明显的过冲，并且过冲幅度随保持时间τ和纤维速度V呈对数增长。基于润湿脊的缓慢生长和力辅助势垒穿越建立了一个统一模型，以解释在老化软表面上观察到的与时间（或状态）和速度（或速率）相关的CL脱钉动力学。这些实验结果对于涉及缺陷或粗糙度景观中脱钉动力学的一类常见问题具有重要意义，例如固体界面的摩擦。
