Relative adsorption excess of ions in binary solvents determined by grazing-incidence X-ray fluorescence.
We demonstrate a model-independent method for experimental determination of the relative surface excess of inorganic ions in binary liquid mixtures, based on grazing-incidence X-ray fluorescence. For this purpose, we probe the ion density profiles in a mixture of water and 2,6-dimethylpyridine containing a hydrophilic salt, potassium chloride. Thereby we demonstrate that the proposed method quantifies in a direct manner the difference between cation and anion excess adsorption in binary solvents with a resolution of one excess ion per 200nm2or better.
Department of Chemistry and Molecular Biology, University of Gothenburg, SE-41296 Gothenburg, Sweden.
Monika
M
Witala
European Synchrotron Radiation Facility, 71 Avenue des Martyrs, F-38000 Grenoble, France.
Oleg
O
Konovalov
Department of Chemistry and Molecular Biology, University of Gothenburg, SE-41296 Gothenburg, Sweden. Electronic address: kim.nygard@chem.gu.se.
Kim
K
Nygård
Adsorption excess; Binary aqueous solvents; Grazing-incidence X-ray fluorescence