Silicone Defqamers : The Performance, but How Do They Act

Experiments on a model silicone defoamer are performed in order to clarify the mechanisms by which they act in an aqueous foaming medium. They include a thermodynamic characterization of the silicone compound and observations of its efficiency. Some criteria generally admitted for a good defoamer are shown to be useless and schematic mechanisms including the long term behaviour of these products are proposed.