Bulk and interfacial properties of solvents: Double-layer structure at the Hg/isomer (C 3 and C 4) diol interface

Abstract

Capacitance-potential curves have been recorded at different concentrations of KF and LiClO 4 in the range c = 5 × 10 −3 to 0.2 mol dm −3 in four isomer diols: 1,2-, 2,3-, 1,3- and 1,4-butanediol. The applicability of the Gouy-Chapman theory has been tested by means of plots of 1/ C vs. 1/ c 1 2 at constant charge. The charge and concentration dependence of the inner-layer capacitance has also been investigated. On the basis of the interfacial behaviour, the diols were divided into two groups differing by the presence or absence of intramolecular hydrogen bonds. The dependence of the capacitance on the bulk permittivity is different within the two groups. This is also the case for specific adsorption of anions and cations. It is concluded that the relative structural features of the two groups of solvents are also retained at the electrode interface.