Modified Wenzel and Cassie equations for wetting on rough surfaces
Analysis of PDEs
2016-09-27 v1 Fluid Dynamics
Abstract
We study a stationary wetting problem on rough and inhomogeneous solid surfaces. We derive a new formula for the apparent contact angle by asymptotic two-scale homogenization method. The formula reduces to a modified Wenzel equation for geometrically rough surfaces and a modified Cassie equation for chemically inhomogeneous surfaces. Unlike the classical Wenzel and Cassie equations, the modified equations correspond to local minimizers of the total interface energy in the solid-liquid-air system, so that they are consistent with experimental observations. The homogenization results are proved rigorously by a variational method.
Cite
@article{arxiv.1609.07628,
title = {Modified Wenzel and Cassie equations for wetting on rough surfaces},
author = {Xianmin Xu},
journal= {arXiv preprint arXiv:1609.07628},
year = {2016}
}