Silver Ion as an Indicator of StructuralChemical Inhomogeneity
in the Surface Layer of Glass Electrode

A. A. Belyustin and I. S. Ivanovskaya

Faculty of Chemistry, St. Petersburg State University (Petrodvorets Branch),
Universitetskii pr. 2, Petrodvorets, 198904 Russia

Abstract—The composition of surface layers in two aluminosilicate electrode glasses NaAl-2805 and NaAl-
2412 (containing 5 and 12 mol % Al₂O₃ and 28 and 24 mol % Na₂O, respectively) treated alternately with 0.1M
solutions of HNO₃, NaNO₃, and AgNO₃ at 40°C was studied by the HF-sectioning technique. The modified sur-
face layers in glasses treated with these solutions are inhomogeneous. The glass NaAl-2805 is characterized by
the leached layer with the structure modified by the hydrolysis–condensation processes and the ion-exchanged
layer with a structure, to a larger extent, similar to the glass structure in the bulk. The leached layer contains the
[AlO_4/2]^–Na⁺ groups whose Na⁺ ions can rapidly exchange with the Ag⁺ ions. Moreover, upon treatment with
AgNO₃ solution, the exchange processes involve the silicate component of glasses. Silver accumulates in the
ion-exchanged layer, which manifests itself as a peak in the concentration profile of Ag. The ion-exchanged
layer in the NaAl-2412 glass is formed nearly from the surface. The accumulation of silver is also observed in
this layer.

Pleiades Publishing home page | journal home page | top

If you have any problems with this server, contact webmaster.