Guannan Mu

The adsorption and corrosion inhibition of anion surfactants on aluminium surface in hydrochloric acid

The adsorption and corrosion inhibition of the anion surfactants such as Dodecyl Sulphonic Acid Sodium Salt (DSASS), Dodecyl Benzene Sulfonic Acid Sodium Salt (DBSASS) and Sodium Dodecyl Sulfate (SDS) on the aluminium surface in hydrochloric acid solution was studied using the weight loss method. It was found that the adsorption of surfactants could prevent aluminum from weight loss and the adsorption accorded with Langmuir equation. The thermodynamic parameters such as adsorption heat, adsorption entropy and adsorption free energy were calculated and the changes of the contact angles of aluminum sheets with and without surfactants were determined. According to the above mentioned experimental results, the relations between the adsorption and corrosion inhibition of the anion surfactants on aluminium surface were discussed.

The effect of neutral red on the corrosion inhibition of cold rolled steel in 1.0 M hydrochloric acid

The corrosion inhibition of neutral red on the corrosion of cold rolled steel in 1.0 M hydrochloric acid (HCl) was studied using weight loss method and potentiodynamic polarization method. Results obtained revealed that neutral red is an effective inhibitor. It was found that the adsorption of neutral red could prevent steel from weight loss and the adsorption accorded with the Langmuir adsorption isotherm. Potentiodynamic polarization studies showed that neutral red mainly acted as a mixed-type inhibitor for steel in 1.0 M hydrochloric acid. Thermodynamic parameters such as adsorption heat, adsorption entropy and adsorption free energy were obtained from experimental data of the temperature studies of the inhibition process at four temperatures ranging from 30 to 45 °C. The most suitable range of inhibitor concentration was discussed. The kinetic data such as apparent activation energies and pre-exponential factors at different concentrations of the inhibitor were calculated, the effect of the apparent activation energies and pre-exponential factors on the corrosion rates of cold rolled steel was discussed. The inhibitive action was satisfactorily explained by using both thermodynamic and kinetic models. Synergism between chloride ion and neutral red was proposed. The results obtained from weight loss and potentiodynamic polarization were in good agreement.