Slippage of polymers at interfaces

The slippage of polymer melts is now well understood. In particular, Hénot et al. have investigated the dependence of the slip length on the viscosity of the sheared polymer melt [1]. They proved that the friction of polymer melt is due to the friction of monomers on the surface.
More recently, we studied the effect of temperature on slippage of polymer melts far above glass transition temperature [2]. We showed that friction is a thermodynamically activated process.

With solutions, the concentration can change the interdigitation between the chains anchored to a surface and the solution. Furthermore, depletion layer may appear. The disentanglement and depletion are competing.

We will present the results of experiments of friction of polystyrene in diethyl phthalate on different substrates. We investigate the dependence of the slip length on concentration of the solutions in the Newtonian and the shear-thinning regimes.

[1] Hénot, Marceau, Drockenmuller, Eric, Léger, Liliane, et al. Friction of polymers: from PDMS melts to PDMS elastomers. ACS Macro Letters, 2018, vol. 7, no 1, p. 112-115

[2] Hénot, Marceau, Grzelka, Marion, Zhang, Jian, et al. Temperature-controlled slip of polymer melts on ideal substrates. In Press