Dynamic properties of CnTAB adsorption layers at the water/oil interface

The dynamic interfacial tension and dilational rheology of alkyltrimethylammonium bromides (C(n)TAB) solutions are studied for n=10, 12, 14 and 16 using drop profile analysis and capillary pressure tensiometry. The experimental data are analyzed on the basis of two theoretical models, the Frumkin Ionic Compressibility and the Langmuir Compressibility models [1]. We show that even the simplified Langmuir Compressibility model is able to adequately describe the dynamic properties of the investigated ionic surfactants. Dynamic experiments point out the difficulties related to short chain surfactants due to their very fast adsorption kinetics which cannot be studied with conventional tensiometer setups. (C) 2012 Elsevier B.V. All rights reserved.