Although friction of liquids on solid surfaces is traditionally linked to wettability, recent works have unveiled the role of the solid’s internal excitations on interfacial dissipation. In order to directly evidence such couplings, we take advantage of the considerable variation of the molecular timescales of supercooled glycerol under mild change of temperature to explore how friction depends on the liquid’s molecular dynamics. Using a dedicated tuning-fork AFM, we measure the slippage of glycerol on mica. We report a 100 fold increase of slip length upon cooling, while liquid-solid friction exhibits a linear scaling with molecular relaxation rate at high temperature. This scaling can be explained by a contribution of mica’s phonons which resonate with density fluctuations in the liquid, allowing efficient momentum transfer to mica. These results suggest that engineering phononic spectra of materials could enhance flow performance in nanofluidic channels and industrially relevant membranes.

尽管液体在固体表面上的摩擦传统上与润湿性有关，但最近的工作揭示了固体内部激发对界面耗散的作用。为了直接证明这种耦合，我们利用过冷甘油在温和的温度变化下分子时间尺度的显着变化来探索摩擦力如何取决于液体的分子动力学。使用专用的音叉原子力显微镜，我们测量了云母上甘油的滑移。我们报告说，冷却时滑移长度增加了 100 倍，而液固摩擦在高温下与分子弛豫率呈线性比例关系。这种缩放可以通过云母声子的贡献来解释，声子与液体中的密度波动共振，从而允许有效的动量传递到云母。这些结果表明，工程材料的声子谱可以增强纳米流体通道和工业相关膜的流动性能。