The direct cause of foam is the presence of surfactants, which reduces the surface tension of the solution. Under the combined effect of this reason and the foam attenuation mechanism, different foam systems exhibit different stability performance mainly related to the following factors: The surface tension of the bubble solution, the surface viscosity of the foam, the viscosity of the solution, the self-healing effect of the surface tension (ie Gibbs surface elasticity and Marangoni effect), the electric double layer repulsion and entropy repulsion of the liquid film, the hydrophobic end structure of the surfactant And steric hindrance, etc., these factors do not exist independently. A change in one factor will cause some other factors to change as well. The main factors that affect the stability of the foam are the elasticity of the liquid film and the rate of drainage. From this perspective, it can be seen that the main factors that affect the stability of the foam in different foam systems are different, and sometimes there are several kinds of effects Factors exist simultaneously and work together. In addition to the above factors, some factors also affect the stability of the foam, such as the size of the foam, the coordination of the solute and the solvent, temperature, pH value, the evaporation rate of the solvent, the degree of impact of the foam, and the adsorption rate of the surfactant Wait.