A systematic and quantitative study of the link between foam slipping and interfacial viscoelasticity.

Aqueous foams are often used under various flow regimes, and one of the biggest challenges is to create predictive models of their complex rheological properties. Previous theoretical and experimental studies have qualitatively characterized the wall slip of foams. We focus on this phenomenon in a 1D geometry, studying the friction force to move a train of foam films in a narrow channel. We perform, and correlate, 1D experiments and interfacial measurements of surface elasticity. We adapt existing models to correctly analyze and interpret 1D data, allowing for comparison with 3D foam slip results. Different mixtures of surfactants allow us to quantify the influence of interfacial properties. In particular, we show for 1D experiments that already with a low elasticity, of order 1 mN m(-1), we leave the regime where the interface can be considered as fluid, to enter a regime where dissipation depends only marginally on surface elasticity.