标题： 纳米缺陷引起的润湿滞后 显示英文标题

标题： Wetting hysteresis induced by nanodefects

摘要： 实际表面的润湿涉及由于普遍存在的缺陷而产生的多种迟滞现象。 在这里，我们阐明了液体前沿在孤立的纳米尺寸缺陷上前进或后退时润湿迟滞的起源。 研究了各种类型的化学和拓扑纳米缺陷，这些缺陷代表了实际异质表面的显著特征。 通过一种创新方法，将微观经典密度泛函理论与用于研究罕见事件的字符串方法相结合，确定了穿过表面异质性的最可能润湿路径。 计算出的崎岖自由能景观表明，迟滞是液体前沿在缺陷处的亚稳态钉扎的结果；热激活缺陷穿越的势垒、钉扎力和迟滞被量化，并与缺陷的几何形状和化学性质相关联，从而允许纳米尺度效应的发生。 我们计算的主要结果是，即使是微弱的纳米尺度缺陷，在一般的微流体实验中难以表征，也可以成为多种迟滞现象的来源，包括纳米气泡的钉扎。 显示英文摘要

摘要： Wetting of actual surfaces involves diverse hysteretic phenomena stemming from ever-present imperfections. Here we clarify the origin of wetting hysteresis for a liquid front advancing or receding across an isolated defect of nanometric size. Various kinds of chemical and topographical nanodefects are investigated which represent salient features of actual heterogeneous surfaces. The most probable wetting path across surface heterogeneities is identified by combining, within an innovative approach, microscopic classical density functional theory and the string method devised for the study of rare events. The computed rugged free energy landscape demonstrates that hysteresis emerges as a consequence of metastable pinning of the liquid front at the defects; the barriers for thermally activated defect crossing, the pinning force, and hysteresis are quantified and related to the geometry and chemistry of the defects allowing for the occurrence of nanoscopic effects. The main result of our calculations is that even weak nanoscale defects, which are difficult to characterize in generic microfluidic experiments, can be the source of a plethora of hysteretical phenomena, including the pinning of nanobubbles.