Characterization of the influence of surfactant adsorption layers on the extraction behavior of heavy metals

The surfactants sodium dodecyl sulphonate, cetylpyridinium chloride and i-octylphenylethoxylate have great influence on the H2O/toluene interface state. They change the zetapotential, the structure and the surface tension depending on the type of their head group, the concentration and the kind of the counter-ions. A comparison of the extraction grade and the results of the interface measurements show that the following parameters improve the mass transfer to metal ions: a) the interface activity of the complex-forming agent or ion exchanger, b) a negative zetapotential, c) a monomolecular adsorption layer of the anionic surfactant.