Abstract:

Bubbles play extremely important roles in our daily life and in the fields of industrial production, medicine, health care, etc. Concerning complex foam systems with different fine structures, they have a variety of flow and stability properties. However, the drainage behavior of complex foam systems has been far less studied compared with simple foams. Herein, the research status and development of dynamics of liquid drainage from complex foam systems are reviewed, including surfactant-aggregate-stabilized foams, nanoparticle-stabilized foams, and oil-water miscible foams. For the surfactant-aggregate-stabilized foam systems, two flow models such as Poiseuille flow and plug flow, and their kinetic equations are introduced. The drainage behaviors of nanoparticle-stabilized foam systems are emphasized in aspects of particle size effects and particle trapping and blocking effects. The two different forms of oil phase （dissolved oil/emulsified oil） have completely different effects on the drainage behavior of oil-water miscible foams. The drainage behaviors of complex foam systems with fine structures have not been well studied yet, and there are many theoretical disagreements and debates. It is necessary to carry out more in-depth research on basic theoretical issues. We believe that the research on the fluid drainage dynamics of complex foam systems will be a research hotspot at present and for a long time in the future.

Key words: complex foam, surfactant, fine structure, drainage dynamics, stability