Giant slip length at a supercooled liquid-solid interface

The effect of temperature on friction and slip at the liquid-solid interface has attracted attention over the last 20 years, both numerically and experimentally. However, the role of temperature on slip close to the glass transition has been less explored. Here we use molecular dynamics to simulate a bidisperse atomic fluid, which can remain liquid below its melting point (supercooled state), to study the effect of temperature on friction and slip length between the liquid and a smooth apolar wall in a broad range of temperatures. At high temperatures, an Arrhenius law fits well the temperature dependence of viscosity, friction, and slip length. In contrast, when the fluid is supercooled, the viscosity becomes super-Arrhenian, while interfacial friction can remain Arrhenian or even drastically decrease when lowering the temperature, resulting in a massive increase of the slip length. We rationalize the observed superlubricity by the surface crystallization of the fluid, and the incommensurability between the structures of the fluid interfacial layer and of the wall. This study calls for experimental investigation of the slip length of supercooled liquids on low surface energy solids.

Automated summary

The effect of temperature on friction and slip at the liquid-solid interface has been studied both numerically and experimentally over the past 20 years. However, the role of temperature on slip close to the glass transition has not been well explored. In this study, molecular dynamics simulations were used to investigate the effect of temperature on friction and slip length in a bidisperse atomic fluid. The results showed that at high temperatures, an Arrhenius law fits well, while in the supercooled state, the viscosity becomes super-Arrhenian and the interfacial friction can drastically decrease, leading to a significant increase in slip length.