Characterization of foam stability by the use of foam models 2. Results and discussion

Abstract

???lems of characterizing foam stability are discussed. Coalescence times for foams of different degrees of complexity ??en defined and determined. Time quantities used in this work are: thinning and bursting times of the film, and ??? coalescence both between a pair of bubbles and between a bubble and the continuous gas phase. Bubble lifetimes ???d strongly on the complexity and structure of the foam and an approximate explanation of this is given. The effects of different factors (surfactant, salt content, temperature, bubble size and foam complexity) on stability are presented for several cases investigated and it is noted that these effects cannot be separately treated in an exact manner because the importance of the individual processes involved in the decomposition may vary considerably when altering any of the parameters. A correct characterization of foam stability is consequently possible only if the foaming in real situations is simulated to the greatest possible extent by the method of investigation.