Abstract: A novel way for analyzing the effect of surfactant on the viscosity of dispersion system was proposed. In the proposed method the effects of the films formed by surfactant molecules on the viscosity of dispersion system was taken into account. And it was suggested that the viscosity of the dispersion system was hardly affected by micelles in the system. It was the film formed by surfactant molecules that was the important factor to affect the viscosity of the dispersion system. The states of the film changed greatly with increasing the amount of surfactant added in the system. There was a maximum value for the viscosity of the dispersion system with the changing of the film states. The film formed by ordered surfactant molecules on the interface of oil and water was beneficial to the increasing of viscosity of the dispersion system. And this kind of film was very useful to the stability of the dispersion system.

Key words: Surfactant, Interface film, Particles in dispersion phase, Viscosity, Micelle, Stability, Dispersion system