Study on the Interaction of Cationic Gemini Surfactant with Sodium Carboxymethyl Cellulose

Abstract

In the present study, the interaction of the anionic polymer sodium carboxymethyl cellulose (NaCMC) with the two cationic gemini surfactant (C 12 -(EO)-E-C 12 and C 12 -(EO) 2 -E-C 12 ) has been investigated by surface tension and turbidity measurements. The co-adsorption of the polymer and the surfactants as well as the formation of highly surface-active polymer-surfactant complex was observed. By inserting the surface tension data into the Gibbs equation it could be shown that the surface layers of the mixed solutions have a multi-level adsorption structure. Comparing the critical adsorption concentration (C 1 ), the critical saturation concentration (C 2 ) and the critical micelle formation concentration (C 3 ) of mixtures with different concentrations, it can be seen that all variables increase with the increase in polymer concentration. In addition, the inorganic salt (NaBr) greatly influences the C 1 , C 2 and C 3 . The salt effects depend on the competition between the salt-enhancing effect and the salt-shielding effect.