A Molecular Dynamics Study on Stability and Thermophysical Properties of Nanoscale Liquid Threads

Abstract

The thermophysical properties and stability characteristics of liquid threads are investigated by molecular dynamics (MD) simulations. Density and pressure profiles are obtained, and properties such as equimolar dividing radius, radius of surface of tension, and surface tension are determined. The relationship between the surface tension and thread radius based on the Gibbs theory of capillarity is derived for the liquid thread, and compared with MD simulation results. It shows that the surface tension rapidly deceases as the radius approaches the molecular scale. The surface tension of a simple binary mixture is also considered. The surface tension relative to that of one-component fluid decreases with increasing the binary ratio of the solute with a strong affinity. For a given binary ratio, the surface tension increases gradually as the affinity coefficient reaches 1.6 and decreases rapidly as it gets larger. The critical wavelength of perturbation for the instability is shown to be smaller than is predicted by the classical theory.