Complete Wetting and Drying at Sinusoidal Walls

We investigate complete wetting and drying at sinusoidally corrugated walls, focusing on how wall geometry and the range of intermolecular interactions affect the growth and shape of adsorbed fluid layers near saturation. We consider two limiting cases: complete drying at purely repulsive walls with short-ranged interactions and complete wetting at attractive walls with long-ranged van der Waals forces. Using nonlocal interfacial Hamiltonian theory and a sharp-kink approximation, we derive scaling relations for the mean interface height and interface corrugation as functions of the wall amplitude and wavelength. We show that short-ranged and long-ranged systems display qualitatively different scaling regimes and asymptotic behavior. The theoretical predictions are tested using fully microscopic density functional theory calculations, which confirm the predicted scaling laws with excellent quantitative agreement, including for strongly corrugated substrates. The results provide a detailed description of wetting and drying phenomena at structured surfaces and demonstrate the important role played by both geometry and the nature of microscopic interactions.

• A. Malijevský, M. Pospíšil, M. Magociová, J. Janek: Complete Wetting and Drying at Sinusoidal Walls. Phys. Rev. E 112, 015502, 2025. DOI