In this work we describe an experimental technique to measure the kinetics of heterogeneous chemical reactions in aqueous electrolytes, trough the continuous measurement of changes in the optical properties of the aqueous media using laser reflectometry near the critical angle. Valuable information of the reaction rates that are taking place in the aqueous side of an electrolyte-glass interface can be obtained if accurate relationships between changes in the reflectance, refraction index, and content of chemical species are established. We report some of these relationships, the experimental methodology, and the mathematical models needed to measure continuously chemical reaction rates, and apply them for the leaching of metallic copper and the dissolution of cupric salts in acidic media. The results show that laser reflectometry near the critical angle can be used as a suitable non-invasive accurate technique to measure in situ the rate of dissolution reactions.

Date Published: 7 September 2010
PDF: 8 pages
Proc. SPIE 7799, Mathematics of Data/Image Coding, Compression, and Encryption with Applications XII, 77990R (7 September 2010); doi: 10.1117/12.862998

Published in SPIE Proceedings Vol. 7799:
Mathematics of Data/Image Coding, Compression, and Encryption with Applications XII
Mark S. Schmalz; Gerhard X. Ritter; Junior Barrera; Jaakko T. Astola, Editor(s)