Slip and friction mechanisms at polymer semi-dilute solutions / solid interfaces

Abstract

The role of the polymer volume fraction, $\varphi$, on steady state slippage and interfacial friction is investigated for a semi-dilute polystyrene solutions in diethyl phthalate in contact with two solid surfaces. Signicant slippage is evidenced for all samples, with slip lengths b obeying a power law dependence. The Navier's interfacial friction coecient, k, is deduced from the slip length measurements and from independent measurements of the solutions viscosity $\eta$. The observed scaling of k versus $\varphi$ clearly excludes a molecular mechanism of friction based on the existence of a depletion layer. Instead, we show that the data of $\eta$($\varphi$) and k($\varphi$) are understood when taking into account the dependence of the solvent friction on $\varphi$. Two models, based on the friction of blobs or of monomers on the solid surface, well describe our data. Both points out that the Navier's interfacial friction is a semi-local phenomenon.

References in corpus (6)

• Friction of polymers: from PDMS melts to PDMS elastomers
• Slip-Mediated Dewetting of Polymer Microdroplets
• Adsorption-Induced Slip Inhibition for Polymer Melts on Ideal Substrates
• Comparison of the slip of a PDMS melt on weakly adsorbing surfaces measured by a new photobleaching-based technique
• Viscoelasticity induced onset of slip at the wall for polymer fluids
• Boundary flow of viscoelastic polyelectrolyte solutions

Cited by in corpus (1)

• Near surface concentration profile of sheared semi-dilute polymer solutions