Origin of line tension for a Lennard-Jones nanodroplet

TL;DR

This paper investigates the origin of line tension in Lennard-Jones nanodroplets by comparing molecular dynamics simulations with density functional theory, revealing that deviations from classical laws are minimal and linked to molecular-scale interface geometry.

Contribution

It provides a detailed analysis of line tension origins in nanodroplets, proposing a molecular-scale geometric interpretation and quantifying the line tension length scale.

Findings

Deviation from Young's law is very small.

Line tension length scale is comparable to molecular size.

Decreases with Young's angle.

Abstract

The existence and origin of line tension has remained controversial in literature. To address this issue we compute the shape of Lennard-Jones nanodrops using molecular dynamics and compare them to density functional theory in the approximation of the sharp kink interface. We show that the deviation from Young's law is very small and would correspond to a typical line tension length scale (defined as line tension divided by surface tension) similar to the molecular size and decreasing with Young's angle. We propose an alternative interpretation based on the geometry of the interface at the molecular scale.