Surface Activity of Complex in Mixed Surfactant Solution

Abstract
The dissociation constant of the complex formed in the mixed and very dilute surfactant solution of 3-(dodecylammonio)-propionate (NDA) and sodium alkylsulfates (C10, C12, C14) (SAS) was determined by measuring surface tension and adsorbed amounts of the solution. The composition in the surface and bulk phases did not coincide at the equimolar mixture. The adsorbed monolayer on the solution consists of the coadsorption of NDA–SAS complex (1:1) and free NDA, while the adsorption of free SAS was almost zero in various concentrations studied. Under these conditions the surface activity of the complex alone was obtained. The relationship between the surface activity and bulk concentration for each mixed solution was discussed in terms of relative adsorbability. The surface activity of the complex was one order of magnitude higher than that of NDA and two orders higher than that of SAS.

This publication has 21 references indexed in Scilit: