Skip to Main content Skip to Navigation
Theses

Splendeur et misère de l'effet lotus

Abstract : Hydrophobic surfaces can be made super-hydrophobic by creating a texture on them. This effect, sometimes referred to as the "fakir" effect, is due to air trapped in the structure : the textured substrate behaves as a composite surface made of solid and air, and displays enhanced hydrophobicity. We give evidence for this effect using forests of micro-pillars which we obtained by micro-fabrication techniques. This situation where the drop sits on the top of the micro-pillars is not always the most stable : the liquid can prefer to fill in the texture. We have studied the transition between these two states by different ways : by pressing on drops, by letting drops evaporate and by carrying impact experiments. We have also achieved surfaces displaying gradients in the density of micro-pillars and have discussed the possibility to observe spontaneous movement of droplets. At last, we have studied the wicking of well-defined surfaces by wetting liquids and have inferred dynamics laws of imbibition.
Complete list of metadatas

Cited literature [86 references]  Display  Hide  Download

https://pastel.archives-ouvertes.fr/tel-00154505
Contributor : Mathilde Reyssat <>
Submitted on : Wednesday, June 13, 2007 - 7:00:27 PM
Last modification on : Saturday, September 26, 2020 - 11:44:03 PM
Long-term archiving on: : Friday, September 21, 2012 - 4:31:12 PM

Identifiers

  • HAL Id : tel-00154505, version 1

Citation

Mathilde Callies Reyssat. Splendeur et misère de l'effet lotus. Physique [physics]. Université Pierre et Marie Curie - Paris VI, 2007. Français. ⟨tel-00154505⟩

Share

Metrics

Record views

2377

Files downloads

9935