Stability, Compatibility with Dry-chemical, and Vapor-security of Foam using Surface Active Agent

Abstract

Many properties of foam using surface active agents were studied for a step on the development of synthetic air foam compound. Surface active agents used in this experiment were shown in Table 1 and 2. And their surface tension were also illustrated in Figure 1, 2 and 3.
The properties studied were foaming property, stability of foam, its compatibility with fuel, dry-chemical and sea-water, and vapor-security of foam or monolayer film.
In order to study the foaming property and stability of foam, foaming ratios and drainage volumes of foam made of 50 ml surface active agent solution by stirring in a 500ml beaker, were measured by receiving in a 50 ml messcylinder. A decline of their properties began at a thicker concentration of agent used. As the drainage speed of simple solution of agent was so fast, many kind of builder solution were added. Then, the drainage time of them were extended.
The compatibility of foam with fuel, dry-chemical, and sea-water were estimated by mixing with 5 ml hexane or methanol, and 1 g dry-chemical (98% sodium hydrogen carbonate with 2% magnesium stearate), and by diluting with artificial sea-water.
For the purpose to secure vapor from fuel surface, the use of foam was tried. A weight loss of cup, which filled up with hexane laying foam on, was measured for comparison by means of strain gage in a vessel kept at a constant temperature of 20±1°C. Figure 9 and 10 show the result. Then, it was concluded that completely fluorinated hydrocarbon derivatives were the most powerful, and ω-H perfluorinated one were more than hydrocarbon derivatives. The author assumes that their difference depended upon surface tension.