The inhibition effect of electrochemical noise, EIS and surface analysis to evaluate N'-bis (2-pyridylmethylidene)- 1,2-diiminoethane (BPIE) Schiff base against AZ91D alloy corrosion in 0.01 mol/L HCl was investig...The inhibition effect of electrochemical noise, EIS and surface analysis to evaluate N'-bis (2-pyridylmethylidene)- 1,2-diiminoethane (BPIE) Schiff base against AZ91D alloy corrosion in 0.01 mol/L HCl was investigated by different electrochemical methods. Potentiodynamic polarization curves revealed that the BPIE acts as a mixed-type corrosion inhibitor. Electrochemical impedance spectroscopy (EIS) measurements confirmed the corrosion inhibition effect of the BPIE. As the inhibitor concentration increased, the charge transfer resistance increased and the double layer capacitance decreased due to more inhibitor adsorption on the surface. The results obtained by analysis of electrochemical noise (EN) data in time and frequency domains are in good agreement with EIS and polarization results. Moreover, scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDX) were used to investigate the corrosion inhibition of the BPIE. SEM images showed that the corrosion damage of the alloy surface reduced in the presence of BPIE. The intensity of the XRD peaks corresponding to magnesium-rich α phase increased in the presence of BPIE, indicating lower corrosion of alloy sample. Also, EDX analysis approved the corrosion inhibition performance of the BPIE. The studied Schiff base compound acts by physical adsorption on the alloy surface and its adsorption obeys the Langmuir isotherm.展开更多
Veratraldehyde was tested as a corrosion inhibitor for mild steel in I M HCI and 0.5 M H2SO4 separately using mass loss and electrochemical studies. The inhibition efficiencies were evaluated at different concentratio...Veratraldehyde was tested as a corrosion inhibitor for mild steel in I M HCI and 0.5 M H2SO4 separately using mass loss and electrochemical studies. The inhibition efficiencies were evaluated at different concentrations of the inhibitor at different temperatures. The inhibition efficiency increased with increase in inhibitor concentration and decreased with increase in temperature in both the acid solutions. Electrochemical studies showed that the inhibitor is of mixed type with a slight predominance of anodic character. The inhibitor was more active in HCI than in H2SO4. The maximum inhibition efficiency approached at 1000 ppm in both the acid medium. The inhibitor was found to adsorb on the mild steel surface according to the Langmuir adsorption isotherm. The surface morphology of mild steel in the presence and absence of inhibitor was studied by using scanning electron microscopic （SEM） images.展开更多
文摘The inhibition effect of electrochemical noise, EIS and surface analysis to evaluate N'-bis (2-pyridylmethylidene)- 1,2-diiminoethane (BPIE) Schiff base against AZ91D alloy corrosion in 0.01 mol/L HCl was investigated by different electrochemical methods. Potentiodynamic polarization curves revealed that the BPIE acts as a mixed-type corrosion inhibitor. Electrochemical impedance spectroscopy (EIS) measurements confirmed the corrosion inhibition effect of the BPIE. As the inhibitor concentration increased, the charge transfer resistance increased and the double layer capacitance decreased due to more inhibitor adsorption on the surface. The results obtained by analysis of electrochemical noise (EN) data in time and frequency domains are in good agreement with EIS and polarization results. Moreover, scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDX) were used to investigate the corrosion inhibition of the BPIE. SEM images showed that the corrosion damage of the alloy surface reduced in the presence of BPIE. The intensity of the XRD peaks corresponding to magnesium-rich α phase increased in the presence of BPIE, indicating lower corrosion of alloy sample. Also, EDX analysis approved the corrosion inhibition performance of the BPIE. The studied Schiff base compound acts by physical adsorption on the alloy surface and its adsorption obeys the Langmuir isotherm.
文摘Veratraldehyde was tested as a corrosion inhibitor for mild steel in I M HCI and 0.5 M H2SO4 separately using mass loss and electrochemical studies. The inhibition efficiencies were evaluated at different concentrations of the inhibitor at different temperatures. The inhibition efficiency increased with increase in inhibitor concentration and decreased with increase in temperature in both the acid solutions. Electrochemical studies showed that the inhibitor is of mixed type with a slight predominance of anodic character. The inhibitor was more active in HCI than in H2SO4. The maximum inhibition efficiency approached at 1000 ppm in both the acid medium. The inhibitor was found to adsorb on the mild steel surface according to the Langmuir adsorption isotherm. The surface morphology of mild steel in the presence and absence of inhibitor was studied by using scanning electron microscopic （SEM） images.
