Effect of Morinda tinctoria leaves extract on the corrosion inhibition of mild steel in acid medium

Abstract

The Morinda tinctoria (MT) plant leaves extract was prepared in aqueous and hydrochloric acid media and was used as corrosion inhibitor for mild steel in hydrochloric acid medium. MT is found to be an efficient inhibitor at room temperature and the efficiency decreases with increase in temperature. Results from colorimetric studies predict the amount of iron present in the test solution and the percentage inhibition efficiency values calculated from this data fit well with the weight loss experiments. The AC impedance studies reveal that the mild steel surface is positively charged and the process of inhibition is through charge transfer. Polarisation studies indicate the mixed nature of the inhibitor. Thermodynamic parameters obtained predict that the process of inhibition is a spontaneous one.

N-methyl-2-(2-nitrobenzylidene) hydrazine carbothioamide — A new corrosion inhibitor for mild steel in 1mol·L−1 hydrochloric acid

“…The new band at 632 cm -1 in the IR spectrum of the scrapped material is due to γ-Fe 2 O 3 [16].The shift in the absorption frequencies indicate that there is an interaction between the inhibitor molecules and the metal surface advocating the adsorption of MNBHC on metal surface.…”

“…This behavior is an indication of physical adsorption of the constituents of the inhibitor on the metal surface [16]. An increase in the activation energy of inhibited system is due to the adsorption of the inhibitor molecules on active sites.…”

Effect of Pharmaceutically Active Compound Nitroxoline on the Corrosion of Mild Steel in an Acidic Environment

“…This process is determined by using the surface coverage data and it plays an important role in the prediction of an adsorption isotherm. The degree of surface coverage ( ) is calculated by using the equation = % IE/100 [16,17]. The values obtained from mass loss studies, impedance studies, and polarization studies were tested with different types of adsorption isotherm at room temperature.…”

Experimental and Theoretical Investigation on Corrosion Inhibition of Mild Steel in Sulphuric Acid by Coccinia Indica Leaves Extract

“…In recent years volumes of literature are available on the use of plant extracts as corrosion inhibitors for MS in acidic media and they have attracted the attention due to their extended applications. [3][4][5] In the search for a natural plant inhibitor, we tumbled upon Coccinia indica (CI), a climber which is available in plenty. The phytochemical database on it suggests that it contains a large number of phytochemical constituents which can be used as corrosion inhibitors.…”