Science China Physics, Mechanics and Astronomy

, Volume 55, Issue 11, pp 2158–2166 | Cite as

A new look on wetting models: continuum analysis

Article

Abstract

In this study, we considered the wetting phenomenon on a general substrate from a new viewpoint of continuum mechanics. The analyses first show how the Wenzel and the Cassie models deviate the practical results in some special substrates, and then elucidate the mechanism of the triple contact line (TCL) moving. Based upon variational theory of the total free functional dealing with the movable boundary condition, we show that the macroscopic contact angle (MCA) expression is the corresponding transversality condition. It manifests that the MCA depends only on the chemical and geometric property at the TCL, and is not affected by the gravity of the droplet and the contact area beneath the liquid. Our continuum model also shows the exploration of the pinning effect on a sharp wedge or the interface between two different phases. This investigation will help designing super-hydrophobic materials for novel micro-fluidic devices.

Keywords

continuum field energy functional transversality condition mechanism-based model triple line moving 

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Copyright information

© Science China Press and Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  1. 1.School of Pipeline and Civil EngineeringChina University of PetroleumQingdaoChina
  2. 2.School of Power and Mechanical EngineeringWuhan UniversityWuhanChina
  3. 3.Department of Mathematics and PhysicsFourth Military Medical UniversityXi’anChina

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