Effect of inorganic electrolyte concentration on anionic-cationic adsorption films. Part 3: Dodecylpyridinium chloride + sodium octylsulfonate + sodium chloride

The effect of sodium chloride concentration on the simultaneous adsorption of dodecylpyridinium chloride (R₁₂PyCl) and sodium octylsulfonate (R₈SO₃Na) on the free surface of their aqueous solutions has been examined. The composition of mixed films adsorbed from equimolar solutions has been determined on the basis of the Gibbs adsorption equation as well as by using the regular solution model. It has been stated that this composition is dependent on the surface tension value (the degree of the surface coverage) as well as on the concentration of added inorganic electrolyte. The same factors influence the value of the interaction parameter , which negative values indicate a strong attraction between the components in the mixed monolayer.