Origin of contact line forces during the retraction of dilute polymer solution drops.
The forced dewetting of water and dilute poly(ethylene oxide) solution (PEO) drops is investigated for syringe-driven flow. Comparisons are made with the free dewetting observed during drop impact. We provide strong evidence that during droplet retraction, polymer deposited on the substrate results in a velocity-dependent force at the contact line. These findings are in stark contrast to previous studies which attributed dissipation to bulk viscoelastic effects or normal stress effects at the contact line.
School of Physics and Astronomy and Nottingham Nanotechnology and Nanoscience Centre, University of Nottingham , University Park, Nottingham NG7 2RD, U.K.
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MI
Smith
J S
JS
Sharp