PT  - JOURNAL ARTICLE
AU  - Kurotani, Yuji
AU  - Tanaka, Hajime
TI  - A novel physical mechanism of liquid flow slippage on a solid surface
AID  - 10.1126/sciadv.aaz0504
DP  - 2020 Mar 01
TA  - Science Advances
PG  - eaaz0504
VI  - 6
IP  - 13
4099  - http://advances.sciencemag.org/content/6/13/eaaz0504.short
4100  - http://advances.sciencemag.org/content/6/13/eaaz0504.full
SO  - Sci Adv2020 Mar 01; 6
AB  - Viscous liquids often exhibit flow slippage on solid walls. The occurrence of flow slippage has a large impact on the liquid transport and the resulting energy dissipation, which are crucial for many applications. It is natural to expect that slippage takes place to reduce the dissipation. However, (i) how the density fluctuation is affected by the presence of the wall and (ii) how slippage takes place through forming a gas layer remained elusive. Here, we report possible answers to these fundamental questions: (i) Density fluctuation is intrinsically enhanced near the wall even in a quiescent state irrespective of the property of wall, and (ii) it is the density dependence of the viscosity that destabilizes the system toward gas-layer formation under shear flow. Our scenario of shear-induced gas-phase formation provides a natural physical explanation for wall slippage of liquid flow, covering the slip length ranging from a microscopic (nanometers) to macroscopic (micrometers) scale.