INTERACTIONS BETWEEN SURFACTANTS AND POLYMERS

A review. Aq. mixts. contg. ionic surfactants and polymers show significant modifications in their physico-chem. properties when the surfactant concn. exceeds a crit. value. Addn. of surfactants, in fact, promotes the adsorption of micelle-like aggregates onto the polymer backbone, up to satn. of its binding-sites. On increasing the surfactant content above the satn. threshold free micelles coexist with the surfactant-satd. polymer. Temp., ionic strength and the nature of surfactant and polymer play a significant role in the interactions between polymers and surfactants. Polymer-surfactant interactions influence the phase behavior of systems contg. water, surfactant and polymer. Significant differences are obsd. when the polymer is non-ionic or bears opposite charges with respect to the surfactant. In the latter case electrostatic effects become dominant with respect to ion-dipole, or hydrophobic, interactions, with dramatic consequences on the soln. behavior and on the equil. between coexisting phases. NMR, thermodn. and kinetic methods were extensively used to study some physico-chem. properties of polymer-surfactant systems, PSS. From the above findings information on the adsorption of micelles onto polymer binding-sites (and on the related thermodn. properties), on aggregate size and on the kinetics of matter exchange between the bulk and polymer-bound micelles is obtained.