Chemical relaxation and equilibrium studies associated with binding of anionic surfactants to neutral polymers

The binding of the surfactants sodium octyl and decyl sulphates (SOS and SDeS) to poly (N-vinylpyrollidone)(PVP) and polyethylene oxide (PEO) has been examined. Equilibrium binding isotherms were obtained from e.m.f. studies using surfactant-ion-selective electrodes. The kinetic data were obtained from measurements of ultrasound absorption. Estimates of the binding rates were obtained by applying a phenomenological theory. It is concluded that, on balance, the surfactant aggregates at concentrations below their c.m.c. and the desorption rate of bound surfactant qualitatively obeys first- order kinetics. The interaction of the surfactant sodium hexadecyl sulphate (SHS) with PEO was also investigated using the pressure-jump apparatus.