Critical point wedge filling and critical point wetting
File(s)resubmission.pdf (1.32 MB)
Accepted version
Author(s)
Malijevsky, Alexandr
Parry, Andrew
Type
Journal Article
Abstract
For simple fluids adsorbed at a planar solid substrate (modeled as an inert wall) it is known that critical-point wetting, that is, the vanishing of the contact angle θ at a temperature Tw lying below that of the critical point Tc, need not occur. While critical-point wetting necessarily happens when the wall-fluid and fluid-fluid forces have the same range (e.g., both are long ranged or both short ranged) nonwetting gaps appear in the surface phase diagram when there is an imbalance between the ranges of these forces. Here we show that despite this, the convergence of the lines of constant contact angle, 0<θ<π, to an ordinary surface phase transition at Tc, means that fluids adsorbed in wedges (and cones) always exhibit critical-point filling (wedge wetting or wedge drying) regardless of the range and imbalance of the forces. We illustrate the necessity of critical-point filling, even in the absence of critical-point wetting, using a microscopic model density functional theory of fluid adsorption in a right angle wedge, with dispersion and also retarded dispersionlike wall-fluid forces. The location and order of the filling phase boundaries are determined and shown to be in excellent agreement with exact thermodynamic requirements and also predictions for critical singularities based on interfacial models.
Date Issued
2024-02-14
Date Acceptance
2024-01-24
Citation
Physical Review E: Statistical, Nonlinear, and Soft Matter Physics, 2024, 109 (2)
ISSN
1539-3755
Publisher
American Physical Society
Journal / Book Title
Physical Review E: Statistical, Nonlinear, and Soft Matter Physics
Volume
109
Issue
2
Copyright Statement
©2024 American Physical Society. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
License URL
Publication Status
Published
Article Number
024802