Corrosion of Copper Metal in Presence of Binary Mixtures

The rates of copper corrosion were determined in presence and in absence of different compositions of water-ethanol, -ethylene glycol, -glycerol, -dimethyl sulfoxide (DMSO) and -dioxane binary mixtures. The rates of corrosion were found to decrease by increasing the concentration of solvents. The percent inhibition range from 10.9 to 78.2% depends on the nature of solvent and its concentration. The calculated energies of activation prove that the reactions are diffusion controlled. Thermodynamic parameters were calculated. The investigated adsorption isotherms indicate that, protic solvents fit the Langmuir model. The rate of corrosion of copper in presence of diphragm is less than that in absence of diphragm due to the prevention of stirring of hydrogen evolved at cathode. The overall mass transfer correlations under the present conditions have been obtained using dimensional analysis method. The results agreed with the previous studies of mass transfer to rotating cylinder in turbulent flow.