Field- and concentration-dependence of electrostatics in non-polar colloidal asphaltene suspensions
Abstract
Electrostatic stabilization has recently been found to be an important factor in non-polar colloidal asphaltene suspensions. However, the nature of charging in asphaltene systems may be quite different than in other non-polar colloid systems. For instance, the origin of charging in asphaltene colloids arises from both positive and negative charges native to the asphaltenes. In part due to this bimodality of surface charge, some dispersants are shown to stabilize asphaltene colloids at concentrations below their cmc. This effect does not arise from ionic effects of the dispersant, but rather from preferential dispersant