ABSTRACT
Self-assembled surfactant nanostructures are important for a wide variety of existing and emerging processes and applications. Adsorbed surfactant aggregates e.g., hemi-micelles and micelles are frequently applied to modify the interfacial properties of solid surfaces in aqueous solutions. This chapter reviews the application atomic force microscopy (AFM) for interpreting mechanical and tribological properties of physisorbed surfactant systems. Quaternary ammonium bromide surfactant systems are presented as a guiding example. The self assembly of surfactant molecules onto solid/liquid interfaces has been extensively studied. Interest in this area has emerged in part due the practical significance of the strong structure–function relationship of the adsorbed surfactant aggregates at the solid–liquid interface. Many surfactant aggregate structures encountered on solid surfaces can be semi-quantitatively modeled as fully elastic films at applied loads below the critical repulsive barrier. The validity of this assumption can be determined by pressing and releasing the three-dimensional surfactant structures with the AFM probe at different rates.
