Formation Kinetics and Viscoelastic Properties of Water/Crude Oil Interfacial Films

Abstract : Viscoelastic interfacial properties of a light paraffinic crude oil/water system were studied in order to determine the formation film kinetics. A drop oscillatory tensiometer was used for measuring the dynamical interfacial tension and elastic (E') / viscous (E”) modulus at different temperatures (20-60°C) and different pulsation frequencies (N). The evolution of these viscoelastic properties is analyzed. Monitoring with time the viscoelastic properties of the interfacial film, our experimental measures after 15 minutes, verified the criterion proposed by Winter and Chambon for the formation of an organized molecular structure. Interface age effect is discussed comparing the values of elasticity moduli, as well as temperature effect on the surface properties and interfacial tension.