Friction in surfactant layers at solid-liquid interfaces

The flow behavior of solutions of three different surfactants through pores of a laser-etched membrane is presented. Partial non-linear flow-pressure curves are obtained and the cross-over between the two linear regimes is interpreted as a stick-slip transition. Two parameters are extracted. The critical shear stress, needed to initiate slip, describes the transition and the slip length, the interfacial friction.