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Physics, chemistry, nanoscience and materials around large instruments › Physique de la matière condensée, étude par l’interaction rayonnement matière Les archives de l'IRAMIS et du DRECAM / Archives of DRECAM and IRAMIS › Matériaux, surfaces et nanostructures Physics and chemistry for life sciences and the environment Physique, chimie, nanosciences et matériaux autour des grands instruments
• Laboratoire Léon Brillouin (LLB) • Leon Brillouin Laboratory (LLB)
• Groupe "Matière molle et biophysique" - MMB
• Neutrons • Activités instrumentales nationales et internationales du LLB - National and internatonial instrumental activities at the LLB • Neutrons • Small Angle Neutron Scattering (PA)
Blob and monomer friction model
Marion Grzelka, Iurii Antoniuk, Éric Drockenmuller, Alexis Chennevière, Liliane Léger, and Frédéric Restagno
The role of the polymer volume fraction, ϕ, on steady-state slippage and interfacial friction is investigated for semi-dilute polystyrene solutions in diethyl phthalate in contact with two solid surfaces. Significant slippage is evidenced for all samples, with slip lengths b obeying a power law dependence. Navier’s interfacial friction coefficient, k, is deduced from the slip length measurements and from independent measurements of the solution viscosity η. The observed scaling of k versus ϕ clearly excludes a molecular mechanism of friction based on the existence of a depletion layer. Instead, we show that the data of η(ϕ) and k(ϕ) are understood when taking into account the dependence of the solvent friction on ϕ. Two models based on the friction of blobs or of monomers on the solid surface well describe our data. Both point out that Navier’s interfacial friction is a semi-local phenomenon.
