Glass - Back to the Future!

Presenting Author:
Kim O. Hofmann

article posted 1 April 2016

Kim O. Hofmann studied physics from 2007-2014 at Technical University Darmstadt, Germany, where his fields of attentions were modern optics and the electrochemistry of lithium ion batteries. Since 2014 he is working on his PhD thesis at the Institute of Physical Chemistry, Justus-Liebig-University Giessen in industrial cooperation with Schott AG in Mainz, Germany.

Faradaic rectification of alternating currents at a Pt electrode in contact with a glass melt

Kim O. Hofmann1,*, Thomas Pfeiffer2, Maria-Louisa Reich2,
Ralf-Dieter Werner2 & Jürgen Janek1
1 Institute of Physical Chemistry, Justus-Liebig-University Giessen,
Heinrich-Buff-Ring 17, 35392 Giessen, Germany
2 Schott AG, Hattenbergstrasse 10, 55122 Mainz, Germany

C. Eden [1] was the first to demonstrate systematically the impact of alternating currents on the stability of platinum electrodes in contact with oxide glass melts. Only few years later, P. Delahay et al [2] presented a to this day valid electrochemical theory on the simultaneous interaction of direct and alternating currents on electrode/electrolyte interfaces. Since then, the theory of Faradaic rectification has been used by electrochemists both to explain general corrosion phenomena or as an analytical tool for the study of electrode kinetics, especially in systems with mixed kinetic control. Surprisingly, the potential benefits of this concept have neither been recognized nor applied in glass science.
In this paper we demonstrate that glass science and advanced analytical electrochemistry can be fruitfully combined to advance the understanding of high temperature kinetics in glass melts. The design of rectification experiments will be shown and how to combine the results with those from additional electrochemical techniques. Furthermore results gained from measurements on appropriate model glass melts will be presented in detail. Finally we will demonstrate that Delahay's theory gives easy access to a complete set of electrochemical parameters that characterize electrochemically driven metal–glass interactions.

[1] Eden, C. (1959): Die Auflösung der Platinelektroden bei der Wechselstromelektrolyse in Glasschmelzen. In Schott, E. (Ed.): Beiträge zur angewandten Glasforschung, Wissenschaftliche Verlagsgesellschaft mbH Stuttgart, p. 68-101.
[2] Delahay, P.; Senda, M.; Weis, C. H. (1961): Faradaic rectification and electrode processes. In: Journal of the American Chemical Society 83 (2), p. 312–322.