Dresden 2009 – scientific programme

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O: Fachverband Oberflächenphysik

O 29: Nanostructures at surfaces: preparation

O 29.9: Talk

Wednesday, March 25, 2009, 12:30–12:45, SCH A01

Metastable wetting on structured surfaces — •Rosa Poetes, Kathrin Holtzmann, and Ullrich Steiner — Cavendish Laboratory, University of Cambridge, Cambridge, UK

Wetting on surfaces has traditionally been divided into hydrophobic and hydrophilic wetting. More complex behaviour on structured surfaces has been explained using the differences between Cassie-Baxter and Wenzel wetting. Recently, it has been shown that other metastable wetting states, which cannot be explained fully by either Wenzel or Cassie-Baxter wetting, can exist on rough or structured surfaces.

We are exploring metastable wetting states on hydrophilic and hydrophobic surfaces. In order to find the parameters influencing the existence and lifetime of metastable wetting states, we use both highly rough non-regular and highly structured regular surfaces with hydrophilic and hydrophobic material properties.

We are exploring the pressure dependence of the metastable states using a water tank for immersion of the samples and also studying how the wetting changes with time. Further, we are exploring the influence of different structural parameters upon the metastable state stability by using highly structured samples with different height, width and overhang ratios.

Understanding the lifetime and stability of metastable wetting states will allow for further research into strong superhydrophobic materials with predictable surface properties.