Nanorheology: An investigation of the boundary condition at hydrophobic and hydrophilic interfaces.
It has been shown that the flow of a simple liquid over a solid surface can violate the so-called no-slip boundary condition. We investigate the flow of polar liquids, water and glycerol, on a hydrophilic Pyrex surface and a hydrophobic surface made of a Self-Assembled Monolayer of OTS (octadecyltrichlorosilane) on Pyrex. We use a Dynamic Surface Force Apparatus (DSFA) which allows one to study the flow of a liquid film confined between two surfaces with a nanometer resolution. No-slip boundary conditions are found for both fluids on hydrophilic surfaces only. Significant slip is found on the hydrophobic surfaces, with a typical length of one hundred nanometers.
Cottin-Bizonne
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Département de Physique des Matériaux (UMR 5586), Université Lyon I, 43 bd du 11 Novembre 1918, 69622 Villeurbanne Cedex, France. ccottin@dpm.univ-lyon1.fr
Jurine
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Baudry
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Crassous
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Restagno
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Charlaix
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