Coating of a textured solidReport as inadecuate

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* Corresponding author 1 LadHyX - Laboratoire d-hydrodynamique 2 PMMH - Physique et mécanique des milieux hétérogenes

Abstract : We discuss how a solid textured with well-defined micropillars entrains a film when extracted out of a bath of wetting liquid. At low withdrawal velocity V, it is shown experimentally that the film exactly fills the gap between the pillars; its thickness hd is independent of V and corresponds to the pillar height hp. At larger velocity, hd slowly increases with V and tends towards the Landau-Levich-Derjaguin LLD thickness h LLD observed on a flat solid. We model the entrainment by adapting the LLD theory to a double layer consisting of liquid trapped inside the texture and covered by a free film. This model allows us to understand quantitatively our different observations and to predict the transition between hp and hLLD. © 2011 Cambridge University Press.

Author: Jacopo Seiwert - Christophe Clanet - David Quéré -



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