Dramatic Slowing Down of Oil/Water/Silica Contact Line Dynamics Driven by Cationic Surfactant Adsorption on the Solid

We report on the contact line dynamics of a triple-phase system silica/oil/water. When oil advances onto silica within water film squeezed between and silica, rim forms in recedes at constant velocity. evidence sharp (three orders magnitude) decrease velocity upon addition cationic surfactants above threshold concentration, which is slightly smaller than critical micellar concentration. show that, with or without surfactant, range small capillary numbers investigated, can be described by friction term that does not reduce to pure hydrodynamical effects. In addition, we derive model successfully accounts for selected rim. further demonstrate strong increase coefficient surfactant bulk concentration results from strongly nonlinear adsorption isotherm silica. From variations spreading parameter surface suggest picture part adsorbed are bound interface trapped under droplet responsible large friction.