Molecular Dynamics Simulation of the Nano- scale Solutal Marangoni Convection

Yosuke Imai; Takuya Yamamoto; Yasunori Okano; Ryuma Sato; Yashuteru Shigeta

Yosuke Imai Department of Materials Engineering Science, Osaka University, Machikaneyama 1-3, Toyonaka, Osaka 563-8531, Japan
Takuya Yamamoto Department of Frontier Science for Advanced Environment, Tohoku University, 6-6-02 Aza Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan
Yasunori Okano Department of Materials Engineering Science, Osaka University, Machikaneyama 1-3, Toyonaka, Osaka 563-8531, Japan
Ryuma Sato Center for Computational Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
Yashuteru Shigeta Center for Computational Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan

Keywords: non-equilibrium molecular dynamics, concentration gradient, Marangoni convection, liquid film, flow fields, nano-scale

Abstract

Non-equilibrium molecular dynamics simulations for the 2- and 3-phase systems were performed to investigate the flow with two free surfaces in a nanoscale, where solute, water, and argon were assigned as each phase. We observed that the behaviors of some 3-phase systems significantly differ from those of 2-phase systems. In all 2- phase systems, the solutes just diffused into the water phase. On the other hand, the solutes were transferred along the liquid-gas interfaces in the case of 3-phase systems with a large surface tension gradient. These results indicated that solutal Marangoni convection existed even in the nano-scale and it affected mass transfer greatly.

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