Electrical interfacial layer surface complexation model

In the area of interfacial charging at the solid/liquid interface of metal oxide aqueous suspensions, the "surface complexation or site binding concept is commonly used [3-20]. This concept is characterised by consideration of specific ionic reactions with surface groups, rather than assuming simple binding of ions to the surface or their accumulation at the interface (adsorption). In the past decade several different models were introduced on the basis of the surface complexation model (SCM) they differ in the assumed structure of the electrical interfacial layer (EIL) and in the proposed mechanisms and stoichiometries of surface reactions leading to surface charge. 

The measurement of the variation of A(AV(t)) often does not give us a direct information on changes in the surfactant or polymer adsorption. So far the models are more or less qualitative. A quantitative model should be able to describe the complex structure of the electric double layer in the interfacial region and to explain peculiarities, such as the surface potential of a bare interface and changes in the potential due to adsorption of nonionic surfactants. 

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