Due to their flexible backbone and unique surface activity, silicones can do many things very well. Existing foam is rapidly collapsed by silicone defoamers.
Due to the smooth surface elasticity and surface viscosity of foam film, it is difficult to break it down. Thanks to the Silicone’s unique features (low surface and interfacial tensions) they de-stabilize the film. This property supports them to flow over the foam film. The antifoam penetrates the pores in the foam and subsequently ruptures them. This is done by the silicone’s low interfacial properties and surface tension, which has the ability of weakening the foam-stabilization properties and in turn collapse it.