Cassie-state wetting investigated by means of a hole-to-pillar density gradient

The superhydrophobicity of rough surfaces owes its existence to heterogeneous wetting. To investigate this phenomenon, density gradients of randomly placed holes and pillars have been fabricated by means of photolithography. On such surfaces, drops can be observed in the Cassie state over the full r...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1985. - 26(2010), 12 vom: 15. Juni, Seite 9465-73
1. Verfasser: Spori, Doris M (VerfasserIn)
Weitere Verfasser: Drobek, Tanja, Zürcher, Stefan, Spencer, Nicholas D
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2010
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article
Beschreibung
Zusammenfassung:The superhydrophobicity of rough surfaces owes its existence to heterogeneous wetting. To investigate this phenomenon, density gradients of randomly placed holes and pillars have been fabricated by means of photolithography. On such surfaces, drops can be observed in the Cassie state over the full range of f(1) (fraction of the drop's footprint area in contact with the solid). The gradient was produced with four different surface chemistries: native PDMS (polydimethylsiloxane), perfluorosilanized PDMS, epoxy, and CH(3)-terminated thiols on gold. It was found that f(1) is the key parameter influencing the static water contact angle. Advancing and receding contact angles at any given position on the gradient are sensitive to the type of surface feature--hole or pillar--that is prevalent. In addition, roll-off angles have been measured and found to be influenced not only by the drop weight but also by suction events, edge pinning, and f(1)
Beschreibung:Date Completed 31.08.2010
Date Revised 10.06.2010
published: Print
Citation Status PubMed-not-MEDLINE
ISSN:1520-5827
DOI:10.1021/la904714c