The influence of adenine on corrosion of copper in chloride solutions

The influence of the concentration of adenine (AD) on the corrosion and the spontaneous dissolution of copper in 1.0 M NaCl solutions of pH 6.8 was studied. The investigations involved electrochemical polarization methods as well as weight loss measurements, quartz crystal microbalance (QCM) techniques and scanning electron microscopy (SEM). The inhibition efficiency increases with an increase in the concentration of AD. An adherent layer of inhibitor is postulated to account for the protective effect. The adsorption of adenine has been found to occur on the surface of copper according to the Langmuir isotherm. The values of standard free energies of adsorption suggest chemical adsorption of AD on copper surface. The use of adenine can effectively prevent various new installations made of copper and exposed to the action of aqueous solutions of chlorides from corrosion damage. (C) 2008 Elsevier Ltd. All rights reserved.