ABSTRACT
Liquid foams may be viewed as structured fluids possessing a complex rheological behavior strongly dependent upon local structure and physicochemical constitution. Interfacial rheological properties possess a direct significance to the rheology of foams, owing both to the adsorption of surfactant to bubble surfaces and the large specific surface encountered with foams. This chapter describes theoretical models are employed to relate inter-facial rheological properties explicitly to foam rheological behavior. It examines various two- and three-dimensional spatially periodic geometrical models. The local kinematics of three-dimensional foam media may, however, be extremely complex. The single space-filling polyhedral structure analyzed to date that minimizes surface area and simultaneously satisfies the mechanical conditions of a stable, dry-foam unit cell is the Kelvin minimal tetrakaidecahedron. Two-dimensional foam model provides a kinematical context for illustrating the effects of interfacial rheological properties on foam rheological behavior in a shear field.
