Interfacial behaviour of Catanionic surfactants

Antonio Stocco (1) , David Carriere (2) , Maximilien Cottat (1) , Dominique Langevin (1)

1 LPS - Laboratoire de Physique des Solides
2 LIONS - Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire

We report a dramatic increase of foam stability for catanionic mixtures (myristic acid and cetyl trimethylammonium bromide, CTABr) with respect to pristine CTABr solutions. This increase was related to the low surface tension, high surface concentration and high viscoelastic compression moduli, as measured with rising bubble experiments and ellipsometry. Dialysis of the catanionic mixtures has been used to decrease the concentration of free surfactant ions (CTA+). The equilibrium surface tension is reached faster for non dialysed samples, due to the presence of these free ions. As a consequence, the foamability of the dialysed solutions is lower. Foam coarsening has been studied using multiple light scattering: it is similar for dialysed and non dialysed samples and much slower than for pure CTABr foams.

Domaines: Chimie théorique et/ou physique; Matière Molle [cond-mat.soft]

Antonio Stocco, David Carriere, Maximilien Cottat, Dominique Langevin. Interfacial behaviour of Catanionic surfactants. Langmuir, 2010, 26 (13), pp.10663-10669. ⟨10.1021/la100954v⟩. ⟨hal-00786300⟩