ABSTRACT
A surfactant, or “surface-active agent,” is a molecule that tends to localize at the interface between two immiscible fluids. Surfactants can act to stabilize droplet dispersions of one fluid in another, they can form their own complex phases as a function of concentration in a solvent, and they can even form incredibly thin stable monolayers at a fluid interface. The key characteristic of any surfactant is that there should be a hydrophobic section and a hydrophilic section to the molecule or even more generally, parts of the molecule with a chemical preference for one solvent or phase over another. Surfactant molecules can come in a variety of different shapes and sizes, and these properties tend to affect their bulk phase behavior and their ability to form different self-assembled structures. Surface tension is strongly affected by the presence of a surfactant. Detergents are cleaning products that act by trapping and removing dirt particles from a substrate.
