Properties of surfactants

1. Reduce surface tension
Reducing surface tension is the most basic function of surfactants. There is a macroscopic tension in the surface layer of a liquid that shrinks the liquid surface to the smallest possible level, that is, surface tension. After adding surfactant, the surfactant forms a thin film on the surface of the liquid and changes the arrangement of molecules on the surface of the liquid, thereby reducing the surface tension.
2. Formation of micelles
Micelles refer to molecularly ordered aggregates that begin to form in large quantities after the surfactant concentration reaches a certain value in an aqueous solution.
Surfactant is dissolved in water. When its concentration is low, it is dispersed as a single molecule or is adsorbed on the surface of the solution to reduce the surface tension. When the concentration of surfactant increases to the point where the solution surface is saturated and can no longer be adsorbed, the surface The molecules of the active agent begin to transfer into the solution (Figure 2a-b). Since the hydrophobic part of the surfactant molecule has a small affinity with water, while the attraction between the hydrophilic parts is greater, when a certain concentration is reached, the hydrophobic parts of many surfactant molecules (generally 50 to 150) will interact with each other. Attract and associate together to form an association, which is a micelle (Figure 2c-d). Micelles come in various shapes, such as spherical, lamellar, and rod-shaped.