Abstract
A theory is presented to describe the wetting phenomena and the contact line depinning as a function of the microstructure of rough surfaces. The noise and fluctuations of the quenched disorder on self-affine rough surfaces play a important role in the analysis of the spreading of liquids on non-planar substrates. By using the long-range noise correlation function, functional relationships that show the influence of surface roughness on the contact angle, the critical surface tension and the depinning of the contact line are derived. Roughness enhances wetting and broadens the three-phase contact line.