Single-foam film stability, mechanisms

Mechanisms of Single-Foam Film Stability. Soap bubbles and soap films have been the focus of scientific interest since the days of Hooke and Newton (2—9). The stability and structure of foams are determined primarily by the relative rate of coalescence of the dispersed gas bubbles (10). The process of coalescence in foams is controlled by the thinning and rupture of the foam films separating the air bubbles. Experimental observations suggest that the lifetime (stability) of foam films is determined primarily by the thinning time rather than by the rupture time. Hence, if the approaching bubbles have equal size, the process of coalescence can be split into three stages ... 

Dippenaar used glass cells to observe the effect of the presence of single solid hydro-phobic particles on the stability of foam films in transmitted light by using a highspeed cine camera [42]. As we outline in Chapter 4, this technique has produced convincing proof of the bridging mechanism of antifoam action by hydrophobic particles. 

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