Adsorption effect of 1-((2-hydroxynaphtalen-1-yl) (phenyl)methyl)urea on the carbon steel corrosion in hydrochloric acid media

作者：Hosseini S M A^*; Bahrami M J; Pilvar P

来源：Materials and Corrosion-Werkstoffe und Korrosion, 2010, 61(10): 866-871.

DOI：10.1002/maco.200905500

The adsorption effect of 1-((2-hydroxynaphtalen-1-yl)(phenyl)methyl)urea (HNPU) on corrosion behavior of carbon steel in 1 M hydrochloric acid solution was investigated using weight loss, potentiostatic polarization, and infrared spectroscopy methods. Surface morphology was studied by scanning electron microscopy (SEM). The experimental results, suggest that HNPU inhibited the corrosion of carbon steel in acid solution and the inhibition efficiencies increased as the concentration of the compound in the solution was increased. The calculated inhibition efficiencies from the two investigated methods were in good agreement. Potentiostatic polarization measurements indicate that HNPU acts as a mixed-type inhibitor. The adsorption of the inhibitor on the carbon steel surface obeys Langmuir adsorption isotherm. The values of activation energy and the thermodynamic parameters, such as adsorption equilibrium constant (K(ads)), adsorption free energy (Delta G(ads)), adsorption heat (Delta H(ads)), and adsorption entropy (Delta S(ads)) values were calculated and discussed. The results obtained from infrared spectra, confirmed the adsorption of inhibitor on the alloy surface after immersion in acidic solution containing HNPU. The SEM analysis indicated that there are more lightly corroded and oxidative steel surface for the specimens after immersion in acidic solution containing HNPU than that in blank.

• 出版日期2010-10