结构润滑性与分子污染：再生、老化与摩擦开关
Structural Lubricity and Molecular Contamination: Rejuvenation, Aging, and Friction Switches
AI总结：
本文通过原子力显微镜和分子动力学模拟，揭示金纳米岛在石墨上的结构润滑体系中存在再生、老化与摩擦开关现象，并阐明分子污染对其影响但不破坏结构润滑性。
摘要：
利用原子力显微镜实验和石墨上金纳米岛分子动力学模拟，我们研究了为何在环境条件下仍能观察到通常与结构润滑性相关的超小摩擦。样品合成后几天内进行的测量揭示了结构润滑体系中此前未发现的现象：再生，即滑动开始后不久动摩擦下降一个数量级；老化，即静置30分钟或更长时间后动摩擦力显著增加；开关，即不同摩擦分支之间的自发跳跃。几周后，这三种效应被大幅抑制。对污染层的成像和模拟提供了一致的图像，说明金纳米岛下方的单层和双层污染以及纳米岛周围的污染如何影响结构润滑性，但不会导致其破坏。
英文摘要：
Using atomic force microscopy experiments and molecular dynamics simulations of gold nanoislands on graphite, we investigate why ultra-small friction commonly associated with structural lubricity can be observed even under ambient conditions. Measurements conducted within a few days after sample synthesis reveal previously undiscovered phenomena in structurally lubric systems: rejuvenation, a drop in kinetic friction of an order of magnitude shortly after the onset of sliding; aging, a significant increase in kinetic friction forces after a rest period of 30 minutes or more; switches, spontaneous jumps between distinct friction branches. These three effects are drastically suppressed a few weeks later. Imaging of a contamination layer and simulations provide a consistent picture of how single- and double-layer contamination underneath the gold nanoislands as well as contamination surrounding the nanoislands affect structural lubricity but not lead to its breakdown.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
