Les acides gras hydroxylés : agro-tensioactifs aux propriétés moussantes originales

Abstract

Hydroxylated fatty acids: Agro-based surfactants with original foaming properties Surfactants, which are molecules bearing a hydrophobic part and a hydrophilic part, are widely used in many daily life products (detergent, cosmetic, pharmaceutical. . .) because of their foaming properties. Indeed, they spontaneously go to the interface between air and water, which stabilizes the thin water films surrounding air bubbles to obtain foams. Currently, since the most used surfactants come from derivatives from petroleum-based products, their replacement by biomolecules is a major issue in the current context of sustainable development and green chemistry. This could promote the use of molecules from agricultural resources, such as hydroxyl fatty acids that can be extracted from oil or from the tegument of fruits and vegetables, as new agro-based surfactants. Here, we present recent research on the surfactant properties of the 12-hydroxy stearic acid coming from the castor oil. This fatty acid has very advantageous foaming properties compared to conventional synthetic surfactant systems: it enables the production of foams which are at the same time very abundant and, remarkably, stables over a span lasting more than 6 months. Moreover, these foams are thermoresponsive because the foam stability can be easily modulated by a simple modification of the temperature.

Multilayering of Surfactant Systems at the Air–Dilute Aqueous Solution Interface

“…32 The equilibrium solution contains tubes with an internal lamellar separation that varies in the range 200-450Å at temperatures from 20 • C up to 70 • when the tubes disperse and form micelles. The external diameter increases from about 0.5 µm at 20 • to a maximum of 5 µm at 50 • C before decreasing again.…”