This document provides an inventory of theoretical and methodological concepts in electrochemistry at the interface between two immiscible electrolyte solutions (ITIES). Definitions of basic relationships are given, together with recommendations for the preferred symbols, terminology, and nomenclature. Methods of study of ITIES are briefly described, current experimental problems are indicated, and representative experimental data are shown. The practical applications of electrochemistry at ITIES are summarized. CONTENTS

Abstract:The voltage-induced assembly of mercaptosuccinic acid-stabilized Au nanoparticles of 1.5 ( 0.4 nm diameter is investigated at the polarizable water|1,2-dichloroethane interface. Admittance measurements and quasi-elastic laser scattering (QELS) studies reveal that the surface concentration of the nanoparticle at the liquid|liquid boundary is reversibly controlled by the applied bias potential. The electrochemical and optical measurements provide no evidence of irreversible aggregation or deposition of the particles at the interface. Analysis of the electrocapillary curves constructed from the dependence of the frequency of the capillary waves on the applied potential and bulk particle concentration indicates that the maximum particle surface density is 3.8 × 10 13 cm -2 , which corresponds to 67% of a square closedpack arrangement. This system provides a unique example of reversible assembly of nanostructures at interfaces, in which the density can be effectively tuned by the applied potential bias.

No abstract

Cobalt porphine (CoP) dissolved in the organic phase of a biphasic system is used to catalyze O(2) reduction by an electron donor, ferrocene (Fc). Using voltammetry at the interface between two immiscible electrolyte solutions (ITIES), it is possible to drive this catalytic reduction at the interface as a function of the applied potential difference, where aqueous protons and organic electron donors combine to reduce O(2). The current signal observed corresponds to a proton-coupled electron transfer (PCET) reaction, as no current and no reaction can be observed in the absence of either the aqueous acid, CoP, Fc, or O(2).

No abstract

No abstract

No abstract

Quartz crystal microbalance measurements are used to investigate the water sorption in the cast Nafion films exposed to water vapor. Equilibrium and kinetic sorption data are reported for H-and Na-form Nafion films of a thickness ca. 0.02 µm. Water sorption isotherms obtained agree well with the literature data for Nafion117. However, the water diffusion coefficients evaluated from the initial sorption and desorption rates by using the theory of diffusion in a plane sheet are ca. 7 orders of magnitude lower than those obtained from sorption measurements in ca. 200 µm thick Nafion117 membranes. It is concluded that the kinetics of water sorption (desorption) in the partially hydrated Nafion exposed to water vapor is controlled by the first-order process of water transfer in and out of the nanoscopic hydrophilic regions (ion clusters) for membranes thinner than 10 µm. On the other hand, the linear diffusion is the rate-determining step of water transport in thick Nafion membranes and in fully hydrated thin Nafion films.