Electrochemical studies on gel/liquid microinterfaces
The study of the interface between two immiscible electrolyte solutions (ITIES) has been developing rapidly since the late 1970's. Taking advantage of recent progress in the study of ultramicroelectrodes, researchers are now interested in microITIES, with which the experimental arrangement can be simplified, because the problem of ohmic drop is greatly reduced. Also, the polymer immobilizing agent has been introduced into the study of ITIES, which extends the possibilities of the ITIES in analytical applications. In this work, the new trends in the study of ITIES are briefly reviewed. By combination of the microITIES with the polymer gel, the transport of several ions (picrate anion, tetramethylammonium cation and several carboxylic acid anions) was studied mainly by means of cyclic voltammetry at the new gel/liquid microinterface between water and nitrobenzene solutions. The transport was found to be diffusion controlled. It was examined whether the gel/liquid microinterface could be employed as an ion-selective (at least an ion-sensitive) sensor for amperometric and potentiometric measurements. Finally, possible directions for further research are indicated.