Abstract: Every commercial formulation that contains surfactant contains a mixture of surfactants. This talk is a short review on surfactant mixtures in water focusing on important concepts that differ from single component systems. The fundamental driving force for such differences is due to enthalpic interactions between surfactants with different head group types. Of particular interest is describing surfactant partitioning to an interface or micelle and how such partitioning can affect observed behavior. The Rubingh equation has several faults, but still is the most popularly used equation to predict mixed micelle behavior. This talk will also explore how adsorption at the air-liquid and solid-liquid differs from partitioning in micelles. The latter in particular can exhibit some very unique behavior, for example the same concentration of surfactant A can yield very different absorbed amounts of A on a surface at different surfactant B concentrations.
