Soft-Glassy Rheology of Asphaltenes at Liquid Interfaces

The presence of asphaltenes in oil and water emulsions promotes emulsion stability, a major concern in the recovery of oil reserves. A number of mechanisms for this stabilizing effect have been proposed recently, including those that implicate the interfacial rheology of asphaltenes as a primary factor. We present interfacial shear rheological data for asphaltenes at liquid–liquid interfaces and show conclusively that asphaltenes at an oil–water interface exhibit a soft-glassy rheological behavior in agreement with the soft-glassy rheology (SGR) model. This characteristic allows the stabilization of emulsions via mechanical resistance to coalescence.