Soapy solutions that give a foam, nothing extraordinary; a soap foam stable for several months, even at 60°C (14°F), it is a bit more. Especially when this foam is produced from a natural substance and may be quickly destroyed, just by modifying its thermal environment; even more when it is reversible. This is a sum up of the work of a team of researchers from the French Scientific Research Centers INRA, CEA and CNRS. It gives access to new applications able to draw the attention of cosmetics or detergents manufacturers.
August 31, 2011
Press release from CEA, CNRS and INRA
Due to their specific texture and the molecules that make them, foams often have detergent properties. The molecules that shall be dispersed in water to get foam are called surface-active agents, or
surfactants
. They come by themselves between air and water. This makes it easy to stabilize very thin water films around the air bubbles of the foam, as per a specific scheme. Thanks to their properties, foams have numerous applications in different sectors, such as cleaning, decontamination, cosmetics, fight against pollution or fires, agribusiness or for the extraction of natural resources.
Foams that last, last, last …
The INRA , CEA and CNRS researchers have focused on a specific surfactant molecule, the 12-Hydroxy Stearic fatty acid, extracted from castor oil. To disperse this molecule, insoluble in water, they added a salt. Then, they have come to the very interesting properties of this surfactant : even in small amounts, it produces a huge quantity of foam that is, above all, stable for more than six months, contrary to "classic" surfactants , which stabilize foams for some hours maximum. The researchers have seen and explained this phenomenon by microscopy and …
