Strongly stable axis

From Eq. (10.58) it is seen that can be defined as the cross point of the VF/Vg (c o) dependence with the abscissa axis (further in the text cl,o will be denoted as C). At large surfactant concentrations when the fraction of the dispersed gas retained in the foam strongly increases, the VF/Vg ratio tends to 1. In this case the whole initial solution is transformed into a foam and further increase in the expansion ratio becomes impossible, so a considerable part of the surfactant remains in the solution, i.e. reGVg =c-cLR cL0- cmn. As indicated by the experiments, at low concentrations ct,o - Cmm there is a region where the VF /Vg (C) dependence becomes linear. The extrapolation of this linear segment gives cmjn. The slope angle of this dependence, equal to VLOn / VtTe(ti -1), can be used to estimate the adsorption, needed for the formation of a stable foam with Pf > 1, in case the value of the specific foam surface area is known. 

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