CREATION OF NONEQUILIBRIUM DIFFUSE DOUBLE LAYERS AND STUDIES OF THEIR RELAXATION

Two sources of nonequilibrium in rapidly created diffuse double layers are examined. One arises from the fact that charge can be injected into an electrode more rapidly than ionic motion can produce the corresponding equilibrium charge distribution in the electrolyte. The second source of nonequilibrium occurs with mixed electrolytes where the equilibrium preferential inclusion of more highly charged ions in the diffuse layer can be achieved no faster than the diffusion-limited rate at which these ions can reach the electrode. Experimental examples of both kinds of nonequilibrium are given and their likely importance as sources of error in electrode kinetic and double-layer capacitance measurements is assessed.