Inhibition of Copper Corrosion by Ethanolamine in 100 ppm NaCl

Abstract

<em>We</em><em> study copper corrosion inhibition by </em><em>ethanolamine (ETA)</em><em>with <strong>(</strong>0, 0.2 ,0.3,0.4,0.5) vol.% concentrations in 100 ppm NaCl solution. This work is carried out by </em><em>potentiodynamic</em><em> measurements and Electrochemical Impedance Spectroscopy (EIS). The substrates'</em><em> surface morphologies are examined by Scanning Electron Microscopy (SEM). </em><em>ETA</em><em>is characterized by </em><em>NMR spectra of </em><em>ETA</em><em>¹</em><em>H and ¹³C and Fourier Transform InfraRed Spectroscopy (FT-IR).Quantum chemical calculation (DFT)</em><em> is conducted to correlate the adsorption mechanism with </em><em>ETA</em><em>molecule structure. </em><em>The results show that</em><em>ETA</em><em> acts as a mixed inhibitor; so at 0.4 vol. %, </em><em>the current density ( i ) and the polarization resistance (Rp) are respectively 0.8µA/cm² and 28.62 Ω.cm²</em><em> with 99.78% corresponding efficiency . </em><em>ETA</em><em> adsorption obeys to Langmuir isotherm and t</em><em>akes place on the copper surface through chemical and physical mixed-type adsorption.</em>