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Fluid Dynamics Seminar

Monday, Sept. 27, 2010, 4:00 PM
Cullimore Lecture Hall, Room 611
New Jersey Institute of Technology

Mathematical modelling of adsorption kinetics and micellization in surfactant systems

Ian Griffiths

Mathematical Institute, University of Oxford

Abstract

Surfactants arise in a wide variety of situations, most commonly in their use as detergents, as well as being important in the petroleum industry and in mineral extraction. When dissolved in solution, due to their hydrophobic nature, surfactant molecules tend to adsorb at a free surface. As the surface becomes saturated with surfactant, molecules shield their hydrophobic components by arranging themselves in clusters within the bulk, called micelles. Despite their ubiquitous nature, much of the dynamic behaviour of surfactants upon dissolution is still not well understood. Here we address two important situations: the adsorption of ionic surfactant at a free surface, and the breakdown of micelles upon dilution. We highlight the limitations of the current theories used to describe these processes and develop mathematical models which capture the behaviour observed empirically. We use asymptotic techniques to obtain analytic solutions to the each of the models which provide important insight into the kinetic behaviour during each of these processes.