The Intrinsic Fragility of the Liquid-Vapor Interface: A Stress Network Perspective

TL;DR

This study uses molecular dynamics simulations to analyze the liquid-vapor interface of a Lennard-Jones fluid, revealing how stress networks influence interface fragility and surface tension across temperatures.

Contribution

It introduces a stress network perspective to understand the intrinsic fragility of liquid-vapor interfaces and their temperature-dependent properties.

Findings

Density profiles damp with increasing temperature.

Stress-clusters' fractal dimension varies linearly with surface tension.

Stress networks become more disjointed at higher temperatures.

Abstract

The evolution of the liquid-vapour interface of a Lennard-Jones fluid is examined with molecular dynamics simulations using the intrinsic sampling method. Results suggest, in agreement with capillary wave theory, clear damping of the density profiles as the temperature is increased. We identify a linear variation of the space-filling nature (fractal dimension) of the stress-clusters at the intrinsic surface with increasing surface tension, or equivalently, with decreasing temperature. A percolation analysis of these stress networks indicates that the stress field is more disjointed at higher temperatures. This leads to more fragile interfaces that result in a reduction in surface tension at higher temperature.