13 research outputs found
Adsorption and inhibitive properties of methanol extract of Eeuphorbia Heterophylla for the corrosion of copper in 0.5 M nitric acid solutions
The adsorption and the inhibitive properties of methanol extract of Euphorbia heterophylla on copper in 0.5 M HNO3 have been studied by weight loss method at different temperatures (30-50°C), potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. Also, the surface morphology was analyzed by scanning electron microscopy (SEM). It was found that the inhibition efficiency increases with increasing extract doses and decreased with increasing temperature. The polarization data revealed that this extract acts as mixed type inhibitor. The adsorption process was more favored at lower temperatures with larger negative standard free energy. The extract was adsorbed physically on the copper surface followed Frumkin isotherm
Investigation of the inhibitive effect of poly(diphenylamine) on corrosion of iron in 0.5M H2SO4 solutions
Polyaniline as Corrosion Inhibitor for Iron in Acid Solutions
In recent years, polymer amines have been
studied as an efficient corrosion inhibitor for iron in acid
media. In this article, the performance of water soluble
polyaniline as corrosion inhibitor for iron in 0.5M H2SO4 has
been evaluated by potentiodynamic polarization, linear polarization,
and electrochemical impedance spectroscopy and
compared with the performance of the aniline monomer. It
has been found that polyaniline is an efficient inhibitor, since the maximum efficiency of 84% has been observed at a
concentration of 100 ppm, whereas the monomer has accelerated the corrosion. FTIR studies have shown that the
polyaniline is strongly adsorbed on the iron surface and
inhibits the corrosion effectively. However, aniline has been found to improve the passivation tendency of iron at higher concentrations