On hydrophobic surfaces, surface textures are generated, which typically look like this:
Cross section of textures at the surface of superhydrophobic surfaces.
Water is sitting at the top of the posts, so the contact area between the drop and the surface is effectively reduced by a factor Φ called the surface fraction.
The real wetted area is s. The apparent wetted area is S. The surface fraction is Φ=s/S.
Left: normal glass; right: with alternating rain and sunshine, self cleaning glass stays cleaner (and hydrophilic) (Saint-Gobain).TiO2 is known (…)
Magasinage means "floating ink" in japanese. In scientific terms, the drawing is made by spreading ink through the so-called Marangoni effect. (…)
Sciences et Ingénierie de la Matière Molle
Soft Matter Sciences and Enginering - UMR 7615
10 rue Vauquelin
75231 PARIS CEDEX 05
FRANCE
ESPCI web site
