超冷的糖醇在上异常摩擦
Mathieu Lizée1, Baptiste Coquinot2, Guilhem Mariette2
1Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, 75005, Paris, France. mathieu.lizee@ens.fr.
Nature communications
|July 20, 2024
概括
液体和固体之间的摩擦取决于分子动力学. 冷却超冷的糖显著增加了滑动长度,揭示了固体振动 (声子) 如何影响液体摩擦.
科学领域:
- 物理 物理学 物理
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
背景情况:
- 传统上,液体-固体摩擦与可湿性有关.
- 最近的研究强调了固体内部激发对界面散射的影响.
- 了解这些合对先进的流体动力学至关重要.
研究的目的:
- 直接证明液体分子动力学与固体摩擦之间的合.
- 为了研究分子时间尺度对液体滑动的影响.
- 探索固体内部激发在界面能量消散中的作用.
主要方法:
- 使用专门的调叉原子力显微镜 (AFM) 来测量上的糖滑落.
- 探索超冷糖醇在温度范围内的行为,以改变分子时间尺度.
- 定量化滑动长度和液体-固体摩擦力作为温度和分子动态的函数.
主要成果:
- 观察到在冷却超冷的甘油后,滑动长度增加了100倍.
- 在更高的温度下证明了液体-固体摩擦和分子放松率之间的线性缩放.
- 确定了光的声子与液体密度波动之间的共振,作为动量转移的关键机制.
结论:
- 固体的内部激发,特别是声子,显著影响液体摩擦.
- 分子动力学和放松率是界面消散的关键因素.
- 工程材料音声谱提供了一种途径,以提高纳米流体和膜的流动性能.
相关概念视频
Surface Tension, Capillary Action, and Viscosity
27.7K
Surface Tension
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
27.7K
Frictional Force
7.9K
When a body is in motion, it encounters resistance because the body interacts with its surroundings. This resistance is known as friction, a common yet complex force whose behavior is still not completely understood. Friction opposes relative motion between systems in contact, but also allows us to move. Friction arises in part due to the roughness of surfaces in contact. For one object to move along a surface, it must rise to where the peaks of the surface can skip along the bottom of the...
7.9K
Viscosity
5.8K
When water is poured into a glass, it falls freely and quickly, whereas if honey or maple syrup is poured over a pancake, it flows slowly and sticks to the surface of the container. This difference in the flow of different kinds of liquids arises due to the fluid friction between the liquid layers and the liquid and the surrounding material. This property of fluids is called fluid viscosity. In this example, water has a lower viscosity than honey and maple syrup.
The SI unit of viscosity is...
The SI unit of viscosity is...
5.8K


