Effect of electric double layer repulsion on oil droplet coalescence process

Abstract

Film drainage between two droplets approaching each other at constant velocity under the influence of electric double layer repulsion is studied systematically. Based on the lubrication equations, a mathematical model is given to govern the evolution of film drainage between two oil droplets. This model consists of three coupled fourth-order nonlinear parabolic partial differential equations describing the dynamic evolution of the film thickness, film pressure and surfactant inter-facial concentration. The numerical method used is the finite element method. The main objective of this research work is to modify the film pressure equation by considering the electric double layer repulsion. The effects of electric double layer repulsion and viscosity ratio on film drainage are investigated theoretically. © 2010 WILEY-VCH Verlag GmbH & Co.