Superhydrophobicity of biological and technical surfaces under moisture condensation : stability in relation to surface structure

The stability of superhydrophobic properties of eight plants and four technical surfaces in respect to water condensation has been compared. Contact and sliding angles were measured after application of water drops of ambient temperature (20 degrees C) onto cooled surfaces. Water evaporating from th...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1985. - 24(2008), 23 vom: 02. Dez., Seite 13591-7
1. Verfasser: Mockenhaupt, Bernd (VerfasserIn)
Weitere Verfasser: Ensikat, Hans-Jürgen, Spaeth, Manuel, Barthlott, Wilhelm
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2008
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article Research Support, Non-U.S. Gov't Water 059QF0KO0R Glycerol PDC6A3C0OX
Beschreibung
Zusammenfassung:The stability of superhydrophobic properties of eight plants and four technical surfaces in respect to water condensation has been compared. Contact and sliding angles were measured after application of water drops of ambient temperature (20 degrees C) onto cooled surfaces. Water evaporating from the drops condensed, due to the temperature difference between the drops and the surface, on the cooled samples, forming "satellite droplets" in the vicinity of the drops. Surface cooling to 15, 10, and 5 degrees C showed a gradual decrease of superhydrophobicity. The decrease was dependent on the specific surface architecture of the sample. The least decrease was found on hierarchically structured surfaces with a combination of a coarse microstructure and submicrometer-sized structures, similar to that of the Lotus leaf. Control experiments with glycerol droplets, which show no evaporation, and thus no condensation, were carried out to verify that the effects with water were caused by condensation from the drop (secondary condensation). Furthermore, the superhydrophobic properties after condensation on cooled surfaces from a humid environment for 10 min were examined. After this period, the surfaces were covered with spherical water droplets, but most samples retained their superhydrophobicity. Again, the best stability of the water-repellent properties was found on hierarchically structured surfaces similar to that of the Lotus leaf
Beschreibung:Date Completed 23.03.2009
Date Revised 21.11.2013
published: Print
Citation Status MEDLINE
ISSN:1520-5827
DOI:10.1021/la802351h