inhibition of copper corrosion by ethanolamine in 100 ppm nacl

we study copper corrosion inhibition by ethanolamine (eta)with (0, 0.2 ,0.3,0.4,0.5) vol.% concentrations in 100 ppm nacl solution. this work is carried out by potentiodynamic measurements and electrochemical impedance spectroscopy (eis). the substrates' surface morphologies are examined by scanning electron microscopy (sem). etais characterized by nmr spectra of eta1h and 13c and fourier transform infrared spectroscopy (ft-ir).quantum chemical calculation (dft) is conducted to correlate the adsorption mechanism with  etamolecule structure. the results show thateta acts as a mixed inhibitor; so at 0.4 vol. %, the current density ( i ) and the polarization resistance (rp) are respectively 0.8µa/cm2 and 28.62 ω.cm2 with  99.78%  corresponding  efficiency . eta adsorption obeys to langmuir isotherm and takes place on the copper surface through chemical and physical mixed-type adsorption.