Determining Sodium Kryptate Adsorption Parameters on a Mercury Electrode in 1 M Na2SO4.

Autor: L. N. Sviridova, E. V. Stenina
Předmět:
Zdroj: Russian Journal of Electrochemistry; Sep2004, Vol. 40 Issue 9, p937-945, 9p
Abstrakt: The adsorption of a complex of sodium cations with a macrocyclic ligand (KryptofixR 222, composition C18H36N2O6) as a function of its concentration in 1 M Na2SO4 is studied by measuring the differential capacitance on a stationary Hg drop. Adsorption parameters of sodium kryptate are found using a regression analysis method and various versions of a model of two parallel capacitors complemented with the Frumkin adsorption isotherm. The differential capacitance curves, calculated on the basis of these, are compared with experimental data. The difference in model versions that most adequately describe the adsorption data, established for systems in 0.1 and 1 M Na2SO4, is explained by the influence of the supporting electrolyte on the adsorption layer structure. Conclusions are made on the absence in the system under study of the salting-out from the bulk solution and on a change in the properties of an adsorption layer of sodium kryptate in the region of potentials of the anodic adsorption–desorption peak following expansion of the adsorption region. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index