Assessing the potentials of free base and gallium metalated tertbutylphthalocyanines as aluminium corrosion inhibitors

Abstract

The adsorption behaviors of 2,9,16,23 tetrakis(4-(tert-butyl)phenoxy)phthalocyanine (1) and gallium (III) 2,9,16,24 tetrakis(4-(tert-butyl)phenoxy)phthalocyanine (2) were studied as corrosion inhibitors at the aluminum−HCl solution interface. In addition to weight loss (gravimetric) and electrochemical methods, the study includes measurements utilizing scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction. The findings of the characterization show that the inhibitor molecules were well adsorbed on the aluminum surface, supporting the gravimetric and electrochemical measurements. At 28 °C and the greatest inhibitor concentration (10 μM), the potentiodynamic polarization method gave inhibition efficiency values of 95.2% (1) and 89.1% (2). These compounds showed good corrosion inhibition efficiencies as mixed-type corrosion inhibitors, but they also had a significant anodic character. Theoretical simulations produced conclusions that closely match experimental data.