Foam, emulsions and micro-emulsions cannot be prepared without the use of surfactants.
A surfactant molecule (Fig. 1.8) has a hydrophilic head and a hydrophobic tail. The head could have a charge and accordingly the molecule would be called anionic, cationic or a neutral surfactant. Many surfactant molecules may come together to form structures known as micelles. These could take various shapes (Fig. 1.9) like spherical, cylindrical and bilayered micelles.
Figure 8: Structure of a surfactant molecule
1 water loving , and hence soluble in water-like substances.
2 water hating, and hence soluble in oil-like substances.
Figure 1.9. Micelles
