Wetting on the microscale : shape of a liquid drop on a microstructured surface at different length scales

Describing wetting of a liquid on a rough or structured surface is a challenge because of the wide range of involved length scales. Nano- and micrometer-sized textures cause pinning of the contact line, reflected in a hysteresis of the contact angle. To investigate contact angles at different length...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 28(2012), 22 vom: 05. Juni, Seite 8392-8
1. Verfasser: Papadopoulos, Periklis (VerfasserIn)
Weitere Verfasser: Deng, Xu, Mammen, Lena, Drotlef, Dirk-Michael, Battagliarin, Glauco, Li, Chen, Müllen, Klaus, Landfester, Katharina, del Campo, Aranzazu, Butt, Hans-Jürgen, Vollmer, Doris
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2012
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article
Beschreibung
Zusammenfassung:Describing wetting of a liquid on a rough or structured surface is a challenge because of the wide range of involved length scales. Nano- and micrometer-sized textures cause pinning of the contact line, reflected in a hysteresis of the contact angle. To investigate contact angles at different length scales, we imaged water drops on arrays of 5 μm high poly(dimethylsiloxane) micropillars. The drops were imaged by laser scanning confocal microscopy (LSCM), which allowed us to quantitatively analyze the local and large-scale drop profile simultaneously. Deviations of the shape of drops from a sphere decay at two different length scales. Close to the pillars, the amplitude of deviations decays exponentially within 1-2 μm. The drop profile approached a sphere at a length scale 1 order of magnitude larger than the pillars' height. The height and position dependence of the contact angles can be understood from the interplay of pinning of the contact line, the principal curvatures set by the topography of the substrate, and the minimization of the air-water interfaces
Beschreibung:Date Completed 06.09.2012
Date Revised 05.06.2012
published: Print-Electronic
ErratumIn: Langmuir. 2012 Jul 3;28(26):10136-9
Citation Status PubMed-not-MEDLINE
ISSN:1520-5827
DOI:10.1021/la300379u