J0550105 液滴-壁面間に働く摩擦力の流路幅依存性に関する分子論的研究([J055-01]マイクロ・ナノスケール熱流体現象(1))

Abstract

We report the channel size dependence of the forces that act on water droplets in a nano-meter order channel. Considering the several different-sized channel models, we evaluate forces between the two hydrophobic walls and water droplets by molecular dynamics simulation and show the channel size dependence in terms of the mechanical coefficients, such as friction coefficient. As a result, we show that when the channel size is less than 50Å, the pressure inside water droplet is larger than the expected values from Young-Laplace equation. Moreover we also clarify that this disagreement derives from the difference between a channel size and a droplet size. In the case of the friction force, we show that the friction coefficient depends on the channel size due to the Laplace pressure. From these results, we clarify that there is the different channel size dependence of the static and dynamic properties of the water droplet compared with the macroscopic case.