Berlin 2012 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 21: Poster: Wetting, Micro and nanofluidics

CPP 21.22: Poster

Wednesday, March 28, 2012, 11:00–13:00, Poster A

Influence of the wettability of the wall on capillary flow — Stefan Fogel, Ute Böhme, and •Ulrich Scheler — Leibniz-Institut für Polymerforschung Dresden e.V., Dresden, Germany

A Newtonian liquid in a capillary usually exhibits a parabolic flow profile resulting from the sticking at the wall. The situation is different in a capillary with a non-wetable wall. A significantly flattened profile is observed. Capillary flow is conveniently studied without any disturbance by flow NMR imaging. For each point in space velocity is determined in three directions. The focus has been on the transition between the two scenarios. Because a non-compressible liquid has been used, continuity requires transverse flow for the transition between the two flow profiles, which has been observed. Transition between the two types of flow profiles takes places over several millimeters and starts long before the change of the wall properties.