Copper corrosion inhibition by triphenylmethane derivatives in sulphuric acid media

Abstract

Triphenylmethane derivatives, namely fuchsin basic (FB) and fuchsin acid (FA), were studied for their possible use as copper corrosion inhibitors in 0.001 to 1.0 M sulphuric acid solutions. Benzotriazole (BTA) was also tested for comparative purposes. These inhibitors were studied in concentrations from 1 × 10-5 to 1 × 10-1 M at temperatures from 298 to 328 K. The gravimetric method was employed to study the protective effect of FB, FA and BTA. The order of inhibition efficiency was BTA > FB > FA. Up to nine adsorption isotherms were tested to fit the experimental data. The best fit was obtained using the Frumkin isotherm model. A thermodynamic/kinetic model of adsorption was also fitted. The projected molecular area of the inhibitors was calculated to elucidate inhibitor orientation in the adsorption process. © 2002 Elsevier Science Ltd. All rights reserved.