Free energy calculations along entropic pathways III. Nucleation of capillary bridges and bubbles

Abstract

Using molecular simulation, we analyze the capillary condensation and evaporation processes for Argon confined in a cylindrical nanopore. For this purpose, we define the entropy of the adsorbed fluid as a reaction coordinate and determine the free energy associated with both processes along entropic pathways. For capillary condensation, we identify a complex free energy profile resulting from the multi-stage nature of this phenomenon. We find capillary condensation to proceed through the nucleation of a liquid bridge across the nanopore, followed by its expansion throughout the pore to give rise to the stable phase of high density. In the case of capillary evaporation, the free energy profile along the entropy pathway also exhibits different regimes, corresponding to the initial destabilization of the layered structure of the fluid followed by the formation, and subsequent expansion, of a bubble across the nanopore.

References in corpus (4)

• Phase behavior of hard spheres confined between parallel hard plates: Manipulation of colloidal crystal structures by confinement
• Monte-Carlo Multiscale Simulation Study of Argon Adsorption/Desorption Hysteresis in Mesoporous Heterogeneous Tubular Pores like MCM-41 or Oxidized Porous Silicon
• Free energy calculations along entropic pathways: I. Homogeneous vapor-liquid nucleation for atomic and molecular systems
• Free energy calculations along entropic pathways: II. Droplet nucleation in binary mixtures

Cited by in corpus (2)

• The central role of entropy in adiabatic ensembles and its application to phase transitions in the grand-isobaric adiabatic ensemble
• Unraveling liquid polymorphism in silicon driven out-of-equilibrium