ABSTRACT
Most consumer products used in everyday life are formulations that contain surfactants. Surfactants are included in these formulations for their two essential properties: their ability to lower the surface or interfacial tension and their capacity to solubilize waterinsoluble compounds. As is shown in this volume, gemini surfactants are superior to conventional surfactants in these two aspects. Another aspect in which gemini surfactants could bring significant improvement is the flow behavior of a surfactant-containing formulation. This aspect is crucial for many chemical engineering processes involving mixing, pumping, or extruding. Rheological properties play an important role when trying to satisfy consumer needs or to influence consumer preferences, and surfactants have been long used as viscosity enhancers in personal care products. Currently, there are some instances where they replace polymers (oil field, DNA analysis, etc.). The concept of a gemini surfactant introduces new structural variables to control the rheology of surfactant-based formulations.
