Capillary rise of yield-stress fluids

In this letter the capillary rise of yield-stress fluids is investigated experimentally. Contrary to the case of simple fluids, the final height reached by yield-stress fluids weakly depends on the gap and is strongly affected by the yield stress and the hydrodynamic boundary conditions. Such dependences suggest that the capillary rise of yield-stress fluids results from a dynamical arrest rather than from a thermodynamic equilibrium. To rationalize these results, we propose and validate an extension of Jurin's law to such complex systems. Finally we show that measuring the final height allows for the determination of both the surface tension and the yield stress. editor's choice Copyright (C) EPLA, 2014