Effect of hydrodynamics, interface capillarity and molecular kinetics on wetting and de-wetting on small cylindrical surfaces

Abstract

Wetting and de-wetting phenomena control many natural and industrial processes. Both statics and dynamics of wetting and de-wetting are still a subject of intensive research. This article presents a novel modelling approach combined with experimental validation for the wetting and de-wetting processes taking place on small cylindrical surfaces, such as wires being vertically withdrawn from a pool of liquid under steady flow conditions and slow withdrawal velocity. In particular, both the contact hydrodynamics and interface molecular kinetics are combined to predict the gas-liquid interface deformation, the dynamic contact angle, and the moving contact line. The nonlinear equations governing the meniscus deformation and molecular kinetics at the moving surface are numerically solved. The outcome of this study is directly relevant to a number of industrial applications, including metallurgical coating of wires. © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.