Mechanisms of Polymer-Surfactant Complex Formation

The most generally accepted model for surfactant-polymer interaction is based on a stepwise sequence of binding between surfactant monomers (S) and the polymer chain (P), with each step governed by the law of mass action, and with unique rate constants, k, controlling each step  

Forces opposing the association of molecules include thermal energy, en-tropic considerations, and repulsive interactions among electrical charges of the same sign. It is clear that the strength and character of surfactant-polymer interactions will depend on the properties of each component and the medium in which the interactions occur. However, even in systems where identical mechanisms are active for different surfactant and/or polymer types, the macroscopic symptoms of those interactions may be manifested in such a way that entirely different conclusions could easily be drawn. 

If the primary mechanism of ionic surfactant-nonionic polymer interaction is hydrophobic or dispersion-related, the adsorption of surfactant will almost 

FIGURE 14.6. While a wide variety of polymers are used in systems with surfactants, those most studied and reported in the literature include common water soluble materials such as those illustrated. 

FIGURE 14.7. If an aqueous polymer-surfactant interaction occurs via the surfactant tail, the resulting complex will generally exhibit modified solution characteristics, usually reflecting a greater interaction with water and an expanded chain conformation. 

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