Regensburg 2019 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 13: Wetting, Fluidics and Liquids at Interfaces and Surfaces (joint session CPP/DY)
DY 13.9: Talk
Tuesday, April 2, 2019, 12:00–12:15, H13
Complex Wetting: flow profiles close to three phase contact lines — •Benedikt Straub1, Franziska Henrich1, and Günter K. Auernhammer2 — 1Max Planck Institute for Polymer Research, Mainz, Germany — 2Leibniz Institute for Polymer Research, Dresden, Germany
Wetting and dewetting behavior on solid surfaces is the crucial process underlying many natural phenomena as well as technical applications like printing or coating of surfaces. Our aim is to study the wetting behavior of surfactant solutions on solid surfaces. Especially the flow profile close to the three phase contact line is highly interesting for modelling efforts.
Three-dimensional flow profiles are measured with an astigmatism particle tracking velocity setup.
Measurements of a receding contact line for pure water show that the theoretical prediction can be reproduced, which is used to validate the system. First results show that surfactants cause a deviation of the flow field in comparison to theoretical predictions for pure liquids. In the case of a receding contact line new air-liquid interface is formed at the three phase contact line. The freshly formed interface is, in comparison to the already existing air-liquid interface, not completely occupied by surfactants. This causes a Marangoni tension in the direction of the contact line along the interface. This Marangoni tension opposes the bulk flow close to the air-liquid interface and causes a deviation of the flow field. In special cases this can lead to an opposing interface flow compared to the bulk flow.