It is common in many industries to use oil as a defoamer to break up existing foams or prevent foams from forming. But with the right surfactants–additives that change the foam’s surface tension–it’s possible to make aqueous foams that are actually stabilized by the presence of oil. This video explores some of the ways that oil can interact with these kinds of foam, beginning with capillary action, which draws the oil up into the junctions between foam films. For more, see Piroird and Lorenceau. (Video credit and submission: K. Piroird)
Oily Foams
