In situ electrochemical-ellipsometry studies of charge-transfer processes at the liquid/liquid interface
Date
2000
Authors
Webster, Richard
Beaglehole, D
Journal Title
Journal ISSN
Volume Title
Publisher
Royal Society of Chemistry
Abstract
In situ ellipsometry has been used to characterise the properties of the interface between 1,2-dichloroethane (containing tetrabutylammonium hexafluorophosphate) and water (containing lithium sulfate) during electrochemical potential step (chronoamperometry) experiments with a four-electrode potentiostat. The ellipsometry behaviour was analysed according to changes in the real Δ(rr) and imaginary Δ(ri) signals measured at the Brewster angle during polarisation of the interface between two immiscible electrolyte solutions (ITIES). It was found that both the Δ(rr) and Δ(ri) responses represented relatively slow changes through the interface profile that scaled reversibly with the sign and magnitude of the potential jumps. The ellipsometry responses provided spectroscopic evidence of ion-transfer and accumulation processes via measurement of changes in the refractive index and variation of the dielectric constant in the interface region. The spectroscopic data were consistent with previous models that indicate the ITIES is composed of a mixed solvent layer with varying penetration of electrolyte ion pairs.
Description
Keywords
Keywords: 1,2 dichloroethane; lithium sulfate; solvent; tetrabutylammonium; water; article; electrochemistry; electrode; ellipsometry; liquid; spectroscopy
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Source
Physical Chemistry Chemical Physics
Type
Journal article