Effect of pyridine as advanced polymeric inhibitor for pure copper: adsorption and corrosion mechanisms

The effect of pyridine (Pyr) on the corrosion of copper in 3 wt% NaCl was investigated using potentiodynamical anodic polarization, weight loss and morphological analysis. The Doehlert design simulation shows that Cpyr and immersion time are the significant factors. In addition, electrochemical measurements revealed that Pyr acts as a mixed-type inhibitor with more pronounced effect on anodic domain and the inhibition efficiency increases with increasing of inhibitor content. The adsorption of Pyr was found to obey the free polymerization during adsorption onto substrate surface. Surface characterization was performed using a scanning electron microscope and a Fourier transform infrared spectrometer, and Pyr has large negative charge in nitrogen and oxygen atoms, which results in a chemisorption of Pyr onto the copper surface and records around 97% of inhibition efficiency.