Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 39, 2017
Previous Article Next Article

Interplay between bulk self-assembly, interfacial and foaming properties in a catanionic surfactant mixture of varying composition

Author affiliations

Abstract

The self-aggregation, surface properties and foamability of the catanionic surfactant mixture cetyltrimethylammonium bromide (CTAB)/sodium octyl sulfonate (SOSo) have been investigated to obtain insight on the relation between bulk nanostructures, surfactant packing, and foam stability and aging. Light microscopy, SANS, cryo-TEM, DLS, surface tension, rheometry and direct photography were used to characterize mixtures with varying CTAB molar fraction, xCTAB. In the bulk, self-assembly is richer in the excess CTAB region than in the excess SOSo one. Starting from neat CTAB micelles and on addition of anionic surfactant, there is a change from small ellipsoidal micelles (1 < xCTAB ≤ 0.80) to large rodlike micelles (0.65 ≤ xCTAB ≤ 0.55) and then to vesicles (0 < xCTAB ≤ 0.50), with coexistence regions in between; SOSo-rich mixtures are thus dominated by vesicles. High size polydispersity for the micelles and vesicles is an intrinsic feature of this system. Foam stability is concomitantly impacted by xCTAB. SOSo is a small mobile molecule and so it disrupts foam stability, irrespective of the presence of vesicles. Foams are thus only stable in the CTAB-rich regions, and SANS shows that the shape of micelles and vesicles is unchanged inside the foam. Foam drainage is thereby mostly controlled by the presence of the elongated micelles through the solution viscosity, whereas coarsening is influenced by dense surfactant packing at the gas–liquid interfaces.

Graphical abstract: Interplay between bulk self-assembly, interfacial and foaming properties in a catanionic surfactant mixture of varying composition

Back to tab navigation

Supplementary files

Article information


Submitted
09 Aug 2017
Accepted
13 Sep 2017
First published
13 Sep 2017

Soft Matter, 2017,13, 7197-7206
Article type
Paper

Interplay between bulk self-assembly, interfacial and foaming properties in a catanionic surfactant mixture of varying composition

J. Ferreira, A. Mikhailovskaya, A. Chenneviere, F. Restagno, F. Cousin, F. Muller, J. Degrouard, A. Salonen and E. F. Marques, Soft Matter, 2017, 13, 7197
DOI: 10.1039/C7SM01601H

Social activity

Search articles by author

Spotlight

Advertisements