Alternate Interpretation of the Change Observed in H+ Ion Concentration Levels of the Aqueous Medium of Metal Oxide Suspensions in Response to Change in the Electrolyte Concentration Levels of the Aqueous Medium

Abstract

Even though the triple-layer surface complexation model provides adequate rationalization of the sensitivity of pH response to change in salt concentration levels of the aqueous media in contact with metal oxides, it is suggested that its interpretation of this phenomenon is probably in error. Reassessment of this estimate by assigning separate phase properties to the charged hydroxylated metal oxide in order to replace its earlier two-dimensional description is believed to provide the path to the more meaningful interpretations of observations believed to be affected through application of Gibbs−Donnan-based logic. Support for the replacement of the triple-layer surface complexation model by a two-phase model is provided by demonstrating the correlatability of results with Gibbs−Donnan-based projections.