THE ELECTRICAL DOUBLE-LAYER AT THE INTERFACE BETWEEN MERCURY AND A POLYETHER ELECTROLYTE .1. TETRAETHYLENE GLYCOL DIMETHYL ETHER SOLUTIONS

Differential capacitance measurements are reported for solutions of Li ClO4 and LiAsF6 in highly purified tetraethylene glycol dimethylether (''tetramer'') et an HMDE. The solvent forms part of a homologous seri es of molecules which range from low molar mass liquids to high molar mass solids. It was necessary to allow for ion association when interp reting the behaviour of the diffuse double layer because of the low re lative permittivity of the tetramer. No significant specific adsorptio n of the anions was detected, although adsorption of ClO4- at high pos itive charge on the electrode appeared greater than that of AsF6-. 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.