Wetting of Argon on CO2

TL;DR

This study investigates the wetting transition of argon on solid CO2, combining high-precision experiments and detailed density-functional calculations, revealing triple-point wetting consistent with experimental observations.

Contribution

It provides the first detailed density-functional analysis with realistic potentials that confirms triple-point wetting of argon on CO2, aligning theory with experiment.

Findings

Observation of triple-point wetting in experiments

Density-functional calculations support experimental results

Contrasts with previous predictions of prewetting transition

Abstract

We have studied the wetting transition of Ar adsorbed on solid CO2 by means of high-precision adsorption isotherms measured with a quartz microbalance. We observe triple-point wetting. At variance with many theoretical studies based on a model adsorption potential, which predict for this system a genuine prewetting transition around 100K we find that a detailed density-functional calculation employing a more realistic adsorption potential leads to triple-point wetting of Ar on CO2, in good agreement with the experiment.