Particle-laden interfaces between two immiscible liquids can be studied by deformations in the dilatational mode . Surface pressure rises as the interfacial layer is compressed due to an increase in surface concentration. Using pendant droplet apparatus as a Langmuir trough, droplet aged in low solubility asphaltene solution were rapidly expanded to the point of droplet detachment, and interfacial tension measured as a function of interfacial area.