Polyelectrolyte-surfactant interactions

P.M. Claesson, A. Dedinaite, M. Fielden, M. Kjellin, and R. Audebert Polyelectrolyte-Surfactant Interactions at Interfaces. Prog. Colloid Polym. Sci. 106, 24 (1997). 

Polyelectrolyte - Surfactant Interactions at Solid-Liquid Interfaces Studied with Surface Force Techniques... 

Particles or macroscopic solid surfaces are present in most of the applications mentioned above. Hence it is important to know how polyelectrolytes and surfactants interact with each other at solid-liquid interfaces. Due to the slow equilibration in many polyelectrolyte-surfactant systems, particularly at interfaces, it is fruitful to distinguish between two situations. In the first case the polyelectrolyte is initially adsorbed at the solid-liquid interface and then the polyelectrolyte is removed from the solution before the surfactant is added. This mimics the situation in many cleaning applications. Most of the studies concerned with polyelectrolyte-surfactant interactions at solid-liquid interfaces belong to this category. 

In this review we focus on polyelectrolyte-surfactant interactions at solid-liquid interfaces as studied with surface force measuring techniques. The last years have seen much progress in this area, and it is timely to recapitulate some main findings. It is, however, clear that in order to understand interfacial properties of polyelectrolyte-surfactant systems one needs to understand bulk association. Further, a multitude of experimental techniques needs to be applied. Recent advances have been made using ellipsometry [34,35], reflectometry [36,37], neutron reflectivity [38], and surface sensitive spectroscopic techniques [39,40], It is also our belief that the... 

One of the fundamental and necessary tasks in the study of polyelectrolyte-surfactant interactions is the determination of surfactant binding isotherms. 

Nystrom B, KJpniksen AL (1997) Dynamic light scattering of a poly(ethylene oxide)-poly(pro-pylene oxide)-poly(ethylene oxide) triblock copolymer in water. Langmuir 13 4520-4526 OkuzaM H, Osada Y (1995) Role and effect of cross-linkage on the polyelectrolyte-surfactant interactions. Macromolecules 28 4554-4557... 

It was of interest for both fundamental understanding and practical use to examine the effects of additional electrolytes on polyelectrolyte-surfactant interactions. Initial studies investigated the effects of NaCl on cationic cellulosic polymer-SLES interactions. For sample preparation via high-throughput screening, the salt was pre-mixed with the surfactant at a 30 1 SLES NaCI ratio. A representative phase diagram is shown in Figure 8. 

The second (and third) models for polyelectrolyte/surfactant interaction are based on the solubility and phase characteristics of the mixed systems. The general form of the solubility diagram of a polyelectrolyte/oppositely charged surfactant system, as illustrated by the Polymer JR/TEALS combination, has been referred to (57). It showed an intermediate zone of precipitation, but clarity for high (and low) concentrations of the surfactant. The line representing systems of maximum insolubility in the log polymer/log surfactant concentration plot had a 45° slope indicating constant composition of the insoluble complexes. 

A recent smes of papers by T. Wallin and P. Linse describe approaches to polyelectrolyte/surfactant interactions based on Monte Carlo simulations and mean field calculations (Langmuir 1996 12 305 J Phys Chem 1996 100 17873 J Phys Chem 1997 B10L5506 Langmuir 1998 14 2490). 

Gong et al.[173] theoretically analyzed the cross-linking effect on the polyelectrolyte - surfactant interaction. They derived stability constant K on the basis of the free-energy minimum principle to predict concentration of bound surfactant molecules at equilibrium. 

Gong, J.P., Osada, Y. Theoretical analysis of the cross-hnking effect on the polyelectrolyte - surfactant interaction. Journal of Physical Chemistry 99, 10971-10975 (1995)... 

Claesson, P. M., Dedinaite, A. and Poptoshev, E., Polyelectrolyte-surfactant interactions at solid-liquid interfaces studied with surface force techniques, in Physical Chemistry of Polyelectrolytes, Radeva, T. (Ed.), Surfactant Science Series, Vol. 99, Marcell Dekker, New York, (2001), 447-507. 

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