title: Dynamic interfacial tension of surfactant solutions.
abstract: The dynamics of surfactant interfacial layers was first discussed more than a century ago. In 1946 the most important work by Ward and Tordai was published which is still the theoretical basis of all new models to describe the time dependence of interfacial properties. In addition to the diffusion controlled adsorption mechanism, many other models have been postulated in literature, however, well performed experiments with well defined surfactant systems have shown that the diffusional transport is the main process governing the entire formation of surfactant adsorption layers. The main prerequisite, in addition to the diffusional transport, is the consideration of the right boundary condition at the interface, given by a respective equation of state. In addition to the classical models of Langmuir and Frumkin, also the so-called reorientation or interfacial aggregation models are to be assumed to reach a quantitative description of respective experimental data. Moreover, the adsorption of surfactants at the interface between water and a gas phase different from air can be strongly influenced by the type of molecules within the gas phase, such as alkane vapours. These oil molecules co-adsorb from the gas phase and change the adsorption kinetics strongly. Besides the discussion of how to apply theoretical adsorption kinetics models correctly, a large number of experimental data are presented and the way of a quantitative analysis of the adsorption mechanism and the main characteristic parameters is presented. This includes micellar solutions as well as mixtures of surfactants of ionic and non-ionic nature.
authors.affiliation: Max-Planck-Institut für Kolloid- und Grenzflächenforschung, Am Mühlenberg 1, 14424 Potsdam, Germany. Electronic address: miller@mpikg.mpg.de.
authors.forename: R
authors.initials: R
authors.lastname: Miller
authors.affiliation: Institute of Colloid Chemistry and Chemistry of Water, 42 Vernadsky Avenue, 03680 Kyiv (Kiev), Ukraine.
authors.forename: E V
authors.initials: EV
authors.lastname: Aksenenko
authors.affiliation: Donetsk Medical University, 16 Ilych Avenue, 83003 Donetsk, Ukraine.
authors.forename: V B
authors.initials: VB
authors.lastname: Fainerman
keywords: Adsorption kinetics models; Effect of co-adsorption of alkanes from the vapour phase; Effect of the equation of state as boundary condition; Micellar solutions; Mixed surfactant solutions; Surfactants