Inhibition of corrosion of mild steel in well water by an aqueous extract of soapnut (Sapindus Trifoliatus)

Inhibition efficiency of an aqueous extract of soapnut (Sapindus Trifoliatus) and Zn2+in controlling corrosion of mild steel in well water at room temperature has been evaluated by using weight loss method, polarization study and AC impedance spectra. Dynamic light scattering and Vickers hardness have also been employed. Weight loss method reveals that the formulation consisting of 10 ml soapnut extract and 50 ppm Zn2+ has 97 % inhibition efficiency in controlling corrosion of mild steel immersed in well water. Synergism parameters suggest that a synergistic effect exists between soapnut extract and Zn2+. Adsorption isotherm of metal surface obeys Langmuir adsorption isotherm. Polarization study reveals that the inhibitor system functions as anodic type of inhibitor. AC impedance spectra confirm the protective film formed on the metal surface. Dynamic light scattering (DLS) study reveals surface is in nano meter scale. The Vickers hardness of metal surface was increases in inhibitor system.

Inhibition of corrosion of mild steel by an alcoholic extract of a seaweed Sargassum muticum

An alcoholic extract of a sea weed Sargassum muticum has been used to control corrosion of mild steel in 0.5 N HCl. Weight loss method and Electrochemical studies have been used in this study. Weight loss study reveals that 500 ppm of the inhibitor offers 99.25 % inhibition efficiency. Polarization study reveals that the inhibitor functions as an anodic inhibitor at higher concentration. The AC impedance spectra confirm the formation of a protective film on the metal surface. Adsorption of inhibitor molecules on the metal surface follows Langmuir adsorption isotherm.

Curcumin Decorated Silver Nanoparticles as Bioinspired Corrosion Inhibitor for Carbon Steel

Background: Curcumin-stabilized silver nanoparticles (Cur-AgNp) synthesized by a facile chemical method. The synthesized AgNp was, for the first time, used as a bio-derived corrosion inhibitor for carbon steel in the 1M sulphamic acid medium. Methods: The electrochemical studies via impedance spectroscopy, potentiodynamic polarization, and surface analysis are reported in the communication. The maximum inhibition efficiency of 92.87% obtained at 800 mgL-1 . Results: The impedance measurements revealed an elevation in the polarization resistance with growth in the inhibitor concentration, which supports the adsorption and inhibition behavior of Cur-AgNp on the steel surface. The inhibitor functioned by adsorption on the steel surface and obeyed the Langmuir kinetic-thermodynamic isotherm with a mixed mode of physical/ chemical adsorption. The potentiodynamic polarization study revealed cathodic predominating behavior. Conclusion: The SEM analysis depicted the development of a protective inhibitor film on the steel substrate, and FTIRATR analysis of the inhibited steel surface supported the adsorption of the corrosion inhibitor on the metallic surface.