The Study of Surface Film Formation: Illustrating the Use and the Selection of Electrochemical Models

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 8 Issue 2 (2003) pp 130-140

The Study of Surface Film Formation: Illustrating the Use and the Selection of Electrochemical Models

Biagio F. Giannetti,^†* Cecilia M. V. B. Almeida,^† Silvia H. Bonilla,^† and Tibor Rabóczkay^‡

^†Instituto de Ciências Exatas e Tecnologia da Universidade Paulista, R. Dr. Bacelar 1212, 04026-002, São Paulo, SP, Brazil and ^‡Instituto de Química da Universidade São Paulo, P.O. Box 26077, Cep 05599-970, São Paulo, SP, Brazil
Received October 25, 2002. Accepted December 23, 2002

Published online: 28 February 2003

Abstract. The main models developed for electrochemically formed films are reviewed and presented in a logical sequence as an initial reference for students and beginning researchers. A didactic approach for the study of film formation is presented. It is based on the establishment of the theoretical basis through the point of view of two imaginary observers. The development of an important number of models makes the selection of a suitable description applicable for a specific film formation process difficult. Because of this, special care over criteria selection is discussed. Experimental results were used in order to illustrate the selection procedure used to select the most suitable model. The experiment illustrates the formation of noncontinuous films generated under potentiodynamic conditions. In order to facilitate access to the models involved in the selection, the useful equations were compiled in tabulated form. The experiment is accompanied by the information necessary to be reproduced; however, if no laboratory facilities are available, the data and discussion in the present text will be enough to reach the proposed objectives.

Key Words: Laboratories and Demonstrations; physical chemistry; interfaces; electrochemistry; film formation

(*) Corresponding author. (E-mail: biafgian@unip.br)

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