Foaming agent Foaming agent A foaming agent is a material that facilitates formation of foam such as a surfactant or a blowing agent. A surfactant, when present in small amounts, reduces surface tension of a liquid (reduces the work needed to create the foam) or increases its colloidal stability by inhibiting coalescence of bubbles. A blowing agent is a gas that forms the gaseous part of the foam. Sodium laureth sulfate, or sodium lauryl ether sulfate (SLES), is a detergent and surfactant found in many personal care products (soaps, shampoos, toothpastes, etc.). It is an inexpensive and effective foamer. Sodium lauryl sulfate
Surface tension exactly equal to the liquid–air surface tension. Because surface tension manifests itself in various effects, it offers a number of paths to its measurement. Which method is optimal depends upon the nature of the liquid being measured, the conditions under which its tension is to be measured, and the stability of its surface when it is deformed. An old style mercury barometer consists of a vertical glass tube about 1 cm in diameter partially filled with mercury, and with a vacuum (called Torricelli's vacuum) in the unfilled volume (see diagram to the right). Notice that the mercury level at the