DESALINATION Desalination 201 (2006) 216–223 www.elsevier.com/locate/desal DESALINATION The effect of some phthalimide derivatives on corrosion behavior of copper in nitric acid A. S. Fouda, A. Abd El-Aal* and A. B. Kandil Chemistry Department, Faculty of Science, Mansoura University, Mansoura, Egypt *Chemistry Department, Faculty of Science, Zagazig University, Zagazig, Egypt E-mail: asfouda@yahoo.com Received 12 April 2004; accepted 29 November 2005 Abstract The inhibition effect of some phthalimide derivatives on the corrosion of copper in acidic media has been investi- gated by weight loss and polarization techniques. Results obtained revealed that these organic compounds are good inhibitors. Galvanostatic polarization studies showed that these compounds are mixed-type inhibitors. The adsorption of these inhibitors on the copper surface obeys Temkin’s adsorption isotherm. The effect of temperature on the corrosion behavior of copper in nitric acid in presence of definite concentration of the inhibitors was studied in the temperature range 30–45°C. The associated activation corrosion and free adsorption energies have been determined. Keywords: Corrosion, phthalimide derivatives, nitric acid, weight loss, galvanostatic polarization. 1. Introduction The use of organic compounds containing nitro- gen as corrosion inhibitors is widely spread for many metals and alloys, little is known of their function because of the complexity of the process. Several mechanisms have been proposed to explain the function of corrosion inhibitors of which the adsorption theory is the most pertinent [1]. The reaction of corrosion inhibitors at the metal-solution interface has been evaluated by adsorption characteristics and also by the thermo- dynamics of adsorption [2–4]. Copper is widely used in various industrial operations and the study of corrosion of copper and its inhibition is a subject of practical significance. Dithioglycolic acid [5], 3-benzamidorhodanine [6], substituted phenols [7], triaryl and trialkyl phos- phates [8], potassium dichromate [9] and some thiourea derivatives [10] have been used as effective acid corrosion inhibitors. Most studies have been concerned with polycrystalline copper surfaces. The present paper deals with the effect of some phthalimide derivatives on the corrosion of cop- per in nitric acid solution. www.elsevier.com/locate/desal *Corresponding author doi:10.1016/j.desal.2005.11.030 0011-9164/06/$– See front matter © 2006 Published by Elsevier B.V.