4. Effect of formulation on foam properties

4.1 State of the art. Efficiency and effectiveness

We saw in the previous sections that the stabilizing phenomena of foams are linked to the presence of the surfactant. One might therefore think that the formulator's job would simply be to select the right ingredient(s), and that there would be no major difficulty, nor any need for a jealously guarded confidential recipe. The reality is quite different, even a hundred years after the work carried out by Laplace, Plateau, Gibbs, Rayleigh, Van der Waals and many other lesser-known scientists, on capillarity and soap films.

In fact, current knowledge indicates that it is extremely difficult, if not impossible, to know exactly which of the many possible phenomena is responsible for one system producing more or less...