Thin films (2.0 nm) of copper on germanium internal reflection elements (IREs) were exposed to 10% gum arabic (aqueous solution), 2% alginic acid (aqueous solution), 1% bacterial culture supernatant (BCS, simulated seawater solution), and 0.5% Pseudomonas atlantica exopolymer (simulated seawater solution) and monitored in situ, real time, with the use of Fourier transform infrared/cylindrical internal reflection/attenuated total reflection spectroscopy as a function of time at ambient conditions. Ancillary graphite furnace atomic absorption spectroscopy was used to monitor the removal process of the copper thin film from the germanium IREs. Results indicate that some of the copper was removed from the Cu/Ge interface by all four polymers and incorporated into the polymer matrix. Thus, biocorrosion of copper was exhibited by the four polymers in the order of alginic acid > gum arabic > BCS > Pseudomonas atlantica exopolymer. The FT-IR/CIR/ATR technique can be successfully used to monitor biocorrosion systems in in situ, real-time settings.
John G. Jolley, Gill G. Geesey, Michael R. Hankins, Randy B. Wright, and Paul L. Wichlacz, "In Situ, Real-Time FT-IR/CIR/ATR Study of the Biocorrosion of Copper by Gum Arabic, Alginic Acid, Bacterial Culture Supernatant and Pseudomonas atlantica Exopolymer," Appl. Spectrosc. 43, 1062-1067 (1989)