Foam production--ratio between foaminess and rate of foam decay.

Foams are usually characterized by the foaminess of their surfactant solutions and the rate of foam decay. These two properties have been described many times separately in the literature. There is a certain correlation between them, which can vary depending on the type and the concentration of the surfactants, the method of foam generation, etc. We suggest with this work a new parameter unifying foaminess and rate of foam decay. The foam production is a parameter, which is a ratio between foaminess and rate of foam decay. It was shown an example how foaminess, rate of foam decay and foam production depends on C/CMC (C - surfactant concentration, CMC - critical micelle concentration) of aqueous solutions of sodium octylsulfate (SOS). In addition, it has been stressed that a number of scientific problems on transient foams can be solved by means of the approach pointed out by this study. An example, for which the foam production depends on the way of foam generation, is given. A new criterion for assessing the ability of the surfactants to stabilize foams has been suggested. Thus, the stronger surfactants do not always produce more stable transient foams than the weaker ones, as usually is assumed.