Molecular Dynamics Study on Effect of Surface Structure in Nanometer Scale on Friction at a Solid-Liquid Interface

Abstract

Effects of various periodic nanometer structures on friction coefficients and behaviors of lubricate liquid molecules were calculated by the classical molecular dynamics simulations. When the wall distance was constant, a friction coefficient decreased and became constant with pressure increase in liquid region. When the wall distance was less than 1.5 nm, a friction coefficient increased under the same pressure condition. A friction coefficient of a surface with periodic linear nanometer structures was less than that of a surface with random nanometer structures. Furthermore, a friction coefficient had a close relationship with the behaviors of liquid molecule and liquid molecules in the region surrounded with a nanostructure and a wall didn't go out even when the upper wall moved.