Publication Date

1989

Document Type

Dissertation/Thesis

First Advisor

Vanýsek, P., 1952-

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Chemistry

LCSH

Electrolytes--Conductivity; Electrochemistry; Surface chemistry

Abstract

The interface between two immiscible electrolytes has been the object of electrochemical studies for some years. Investigators have introduced various discoveries, improvements and enhancement. One problem which still remains is the effect of a potential loss in the electrochemical system due to the current (I) flowing through the electrolyte resistance (R). It is desirable to keep the effect of this IR drop to a minimum. Reduction of IR drop effects in a solid electrode electrochemistry has been shown to be possible with ultramicroelectrodes. Potential losses are reduced because of the relative diminishing of current density. This realization has extended the use of ultramicroelectrodes in electrochemical measurements not only to aqueous solutions but to nonaqueous solvents of low conductivity as well. This advancement has inspired a number of electrochemists concerned with processes on liquid-liquid interfaces to investigate the possibilities of forming immiscible liquid microinterface and examine its merits. Taylor and Girault pioneered the research on microinterfaces and we had aimed to continue it. Electrochemical response of a very small interface formed between two immiscible solutions of electrolytes is examined in this thesis. The diameter of the microhole in a thin glass separating the two immiscible solvents used in these studies was approximately 130 micrometers. Modes of ion transport across the nitrobenzene-water interface have been investigated by the addition of semihydrophobic ions like tetramethylammonium, tetraethylammonium, picrate, choline and dodecylsulfate to either aqueous or nonaqueous phase. The primary technique of analysis was cyclic voltammetry. The behavior observed with the microinterface generally resembled the response of a solid ultramicroelectrode of a similar radius. The symmetry of the diffusion pattern was dictated by the size of the microinterface. Response of a small interface is governed by hemispherical diffusion as opposed to a larger interface where the pattern is semilinear. The cell arrangement allowed voltammetric measurements to be carried out without a potentiostat, and solvent resistance and the associated IR drop did not seem to be a problem. An alternative approach to create microinterfaces was to use Nucleopore membrane filters with known pore size. Preliminary results of the study are presented and future research plans are outlined.

Comments

Includes bibliographical references (pages 96-100)

Extent

vii, 100 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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