Factors Controlling the Stability of Colloid Stabilized Emulsions IV. Evaluating the Effectiveness of Demulsifiers

It is shown through measurements of interfacial rheology that the effectiveness of demulsifiers is directly correlated with short relaxation times (for viscoelastic interfaces) and lower dilational elasticities and viscosities of the oil-water interface. Short relaxation times imply that interfacial tension gradients that slow film thinning are suppressed. A reduction in interparticle interactions at the interface results in smaller dilational elasticities and viscosities as well as a decrease in the magnitude of steric hindrance.