The droplet evaporation/condensation transition in a finite volume

TL;DR

This paper investigates the droplet evaporation/condensation transition in finite volumes, providing simulation evidence and a phenomenological theory for the transition behavior in a Lennard-Jones fluid.

Contribution

It introduces a detailed analysis of the finite-volume droplet transition, including scaling laws and simulation validation, advancing understanding of phase coexistence in confined systems.

Findings

Identification of a first-order transition in finite systems

Scaling law for chemical potential difference at transition

Simulation validation using Lennard-Jones model

Abstract

A fluid in the NVT ensemble at T less than the critical temperature T_c and rho = N/V somewhat in excess of rho_coex (density of the saturated gas in the gas-liquid transition) is considered. For V->infinity, a macroscopic liquid droplet coexists with surrounding saturated gas according to the lever rule. For finite V, droplets can only exist if they exceed a minimum size. A (rounded) first order transition of the system occurs when the droplet evaporates into the supersaturated gas.Simulation evidence for this transition is given for a Lennard-Jones model and interpreted by a phenomenological theory. At the transition, the chemical potential difference mu_t-mu_coex scales like L^(-d/(d+1)) for a cubic volume V=L^d in d dimensions, as L->infinity.