APPLICATION OF THE REGULAR SOLUTION MODEL TO ANIONIC CATIONIC ADSORPTION FILMS

The composition and mutual interactions of the components in anionic-cationic adsorption films have been calculated by using a regular solution model of the mixed monolayers. The components of the mixtures investigated were sodium alkylsulfonates and alkylpyridinium halides. It has been stated that the composition of monolayers adsorbed from equimolar solutions is close to that obtained on the basis of the Gibbs surface excesses and is dependent on the surface tension value (the degree of surface coverage), the difference in the surface activity of the components (except for the solutions in pure water) as well as the concentration and type of added inorganic electrolyte. The same factors influence the value of the interaction parameter beta, for which negative values indicate a strong attraction between the components in the mixed monolayers.