The electrical double layer at the interface between mercury and a polyether electrolyte: Part 1: Tetraethylene glycol dimethyl ether solutions

Abstract

Differential capacitance measurements are reported for solutions of LiClO 4 and LiAsF 6 in highly purified tetraethylene glycol dimethylether (“tetramer”) at an HMDE. The solvent forms part of a homologous series of molecules which range from low molar mass liquids to high molar mass solids. It was necessary to allow for ion association when interpreting the behaviour of the diffuse double layer because of the low relative permittivity of the tetramer. No significant specific adsorption of the anions was detected, although adsorption of ClO 4 − at high positive charge on the electrode appeared greater than that of AsF 6 −. The inner layer capacitance behaved in the manner of Parsons' “Group 1” and “Group 2” solvents, and the values were fitted to a four state model.