Contributed by Daniel Daniel
Soap films are thin layers of liquid (usually water) surrounded by air. A soap bubble is essentially of a thin layer of water film that separates the air inside and outside of the bubble. Another example where soap films are found is foam, which consists of a network of thin water films that are connected in accordance to Plateau's laws, which will be explained in a later section. Soap films are stable due to the presence of surfactants, usually ampiphilic molecules, such as sodium dodecyl sulfate which has a hydrophilic head that interacts preferentially with water and a hydrophobic tail that interacts preferentially with air. This is schematically shown in figure 1.
Physics of soap film