Insight into kinetics and mechanisms of AOT vesicle adsorption on silica in unfavorable conditions

The structure of adsorbed surfactant layers at equilibrium state has already been investigated using various experimental techniques. However, the comprehension of the formation of structural intermediates in non-equilibrium states and the resulting adsorption kinetics still remains a challenging task. The temporal characterization of these intermediate structures provides further understanding of the layer structure at equilibrium and of the main interactions involved in the adsorption process. In this article, we studied adsorption kinetics of AOT vesicles on silica at different pH at ambient temperature. AOT vesicles were formed in a brine solution. Quartz crystal microbalance with dissipation monitoring (QCM-D) was used to obtain information on the kinetics of surfactant adsorption and on the structure of the adsorbed layer at the equilibrium state. Additionally, neutron reflectivity experiments were performed to provide a detailed description of the mean surfactant concentration profile normal to the...