Complete Wetting and Drying at Sinusoidal Walls

TL;DR

This paper explores how sinusoidal wall geometry and different interaction ranges influence wetting and drying phenomena, deriving scaling laws and validating them with density functional theory.

Contribution

It introduces a combined analysis of short- and long-range interactions on wetting/drying at corrugated walls, deriving new scaling relations and contrasting effects.

Findings

Distinct scaling regimes identified based on wall corrugation

Short-range and long-range interactions have contrasting effects

Numerical results support theoretical predictions

Abstract

We investigate complete wetting and drying at sinusoidally corrugated solid walls, focusing on the effects of wall geometry and interaction range. Two distinct interaction models are considered: one incorporating only short-ranged (SR) forces (applied to drying), and another including long-ranged (LR) van der Waals interactions (applied to wetting). The SR model is analyzed within the framework of nonlocal Hamiltonian theory by Parry et al., while the LR model is treated using a sharp-kink approximation. In both cases, we derive scaling relations that describe the dependence of the adsorbed layer's width and morphology on the wall's geometric parameters as the system approaches two-phase coexistence. We identify distinct scaling regimes determined by the degree of wall corrugation and highlight the contrasting effects of SR and LR interactions. Theoretical predictions are corroborated by numerical results from classical density functional theory.