Rheology of Aqueous Foams: A Literature Review of some Experimental Works

Abstract

Foam is a dispersed system and is unstable by nature, its rheological characterization is very difficult. Numerous parameters have to be considered and controlled: foam quality, i.e. gas volume fraction, foam texture (bubbles size distribution), size of the measurement apparatus compared to bubbles size, influence of foam production method, wall slip phenomena and foam compressibility. Foam must be stable and must not evolve during measurement time. These numerous parameters do explain there is no general view concerning the behavior of this kind of system. Influence of pressure and temperature has not been the subject of many studies, even on static foam. A rigorous experimental method should consider and control each of these parameters affecting foam stability and structure.