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

Abstract

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.