Polymers surfactant-polymer systems

The earliest investigations of SPI in EOR were done by Trushenski and coworkers (1, 6). They reported that high mobility and phase separation can occur due to SPI. Szabo (7 ) studied several surfactant-polymer systems, and found that mixtures of sulfonates and polymer solutions separated into two or three phases. The above groups investigated aqueous solutions only, and the mechanism of interaction was not clearly defined. 

Most adsorption systems of practical importance contain strongly adsorbing species (multivalent cations and anions, surfactants, polymers). Systems without specific adsorption are difficult to realize even under laboratory conditions due to omnipresent strongly adsorbing impurities (cf. Chapter 3). On the other hand, the primary surface charging occurs also in more complex systems and it must be taken into account in modeling of specific adsorption. 

Because the main driving force for surfactant self-association in polymer-surfactant mixed systems is the hydrophobic effect, the binding of surfactants to polyelectrolytes exhibits a similar dependence on the length of the alkyl chain as known for free micellization. Surfactants with longer hydrocarbon chains bind more strongly to polyions than those with shorter chains, and the binding starts a lower surfactant concentrations. In this context, a convenient parameter to characterize polyelectrolyte-surfactant systems is the critical aggregation concentration, cac, which is a counterpart of the well-known critical micellization concentration, cmc, but applies to solutions of surfactants in the presence of a polymer. It is defined as the... 

This paper presents observations on the difference in behavior of emulsification processes which can occur during surfactant and caustic flooding in enhanced recovery of petroleum. Cinephotomicrographic observations on emulsion characteristics generated at the California crude oil-alkaline solution interface as well as in the Illinois crude oil-petroleum sulfonate system are reported. The interdroplet coalescence behavior of oil-water emulsion systems appear to be quite different in enhanced oil recovery processes employing various alkaline agents as opposed to surfactant/polymer systems. 

With respect to the rheological parameters fliey come to the conclusion that surface elasticity effects are superior to surface viscosity effects. This, however, apphes to pure surfactant layers and may be different for pure protein or mixed surfactant/protein adsorption layers. It has been stressed also by Langevin (26), in her review on foams and emulsions, fliat studies on the dynamics of adsorption and dilational rheology studies for mixed systems, in particular surfactant-polymer systems, are desirable in order to understand these most common stabilizing systems. 

Part Two, Surfactants, contains chapters on the four major classes of surfactants, i.e. anionics, nonionics, cationics and zwitterionics, as well as chapters on polymeric surfactants, hydrotropes and novel surfactants. The physico-chemical properties of surfactants and properties of liquid crystalline phases are the topics of two comprehensive chapters. The industrially important areas of surfactant-polymer systems and environmental aspects of surfactants are treated in some detail. Finally, one chapter is devoted to computer simulations of surfactant systems. 

Surfactant-polymer systems have additional technological significance because surfactants are normally used in emulsion polymerization processes. 

Kwak, J.C.T. (ed.), Surfactant-Polymer Systems, Marcel Dekker, New York, 1998. 

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