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This paper aims at finding the experimentally controllable variables of solvent for the electric double layer capacitance obtained at two parallel platinum wire electrodes in the polarized potential domain. The equivalent circuit used is the frequency-dependent double layer impedance in series with solution resistance. The evaluated capacitance shows no systematic relation with the dielectric constants, viscosity, boiling temperatures, or dipole moments of the solvents but is proportional to the inverse of the lengths of field-oriented molecules. The proportionality indicates common saturated dielectric constants, 6, of 13 solvents. The variables controlling the capacitance are the saturated dielectric constants and the lengths of solvent molecules along the dipole.

Electrically conducting redox-active particles were synthesized by coating near-monodisperse, micrometer-sized polystyrene latex particles (1.62 μm diameter) with polyaniline at 0 °C. This low-temperature synthesis route ensured that high-quality polyaniline was produced. The purified particles were dispersed in an aqueous acidic surfactant solution. According to bulk electrolysis measurements, the reduction of each latex particle leads to the transfer of n = 1.7 × 109 electrons. The acidic suspension showed a cathodic peak at 0.10 V and a very small anodic peak at 0.20 V. The former feature corresponds to the reduction wave, i.e., the conversion of polyaniline from its electrically conducting emeraldine form to its insulating leucoemeraldine state. The cathodic wave varied from a surface wave at lower latex concentration to a diffusion wave at higher latex concentration. The peak current varied linearly with the square root of the potential scan rate, giving a value of n similar to that obtained from bulk electrolysis. The irreversibility of the voltammogram, i.e., the disappearance of the anodic wave, was ascribed to such a short time of collision with the electrode that the conducting zone can propagate only to a small domain near the collision point.

The behavior of electric double layers at polarized interfaces in KC1 solutions is revisited in order to examine properties of the constant phase element (CPE). We pay attention specifically to frequency dependence of both the capacitance and the resistance. Two parallel platinum wires immersed in solution are used as insulator-free * C orresponding author, phone +81