Interactions of Surfactants with Polymers and Proteins

This chapter considers the interaction either in terms of the binding of surfactant molecules to a polymer molecule or in terms of the effect of the polymer chains on surfactant self-assembly. The interactions responsible for association phenomena in polymer-surfactant systems are: hydrophobic interactions between polymer and surfactant molecules, hydrophobic interactions between surfactant molecules, electrostatic interactions between polymer and surfactant molecules, electrostatic interactions between polymer molecules, and electrostatic interactions between surfactant molecules. Salt will screen the electrostatic repulsion between the polymer molecules, and if the backbone of the polymer system is hydrophobic enough, phase separation may occur. The leveling out of the binding isotherm at higher surfactant concentrations is due to saturation of the polymer with surfactant and indicates the maximum amount of surfactant that can be bound per polymer unit. The strength of the interaction varies considerably between the different types of polymer-surfactant systems. There are different ways of approaching the problem of describing the equilibria in polymer-surfactant systems.