Evaluation of Fuji Apple Peel Extract as a Corrosion Inhibitor for Carbon Steel in a Saline Medium

Abstract

The present study evaluated the activity of extract obtained from the peel of Fuji apples (Malus Domestica) harvested in the region of Valparaiso, Chile, as a potential corrosion inhibitor for carbon steel in a saline medium. The total phenol and flavonoid content in the extract was measured and its main components were identified using HPLC-MS. The inhibition efficiency of the extract was evaluated by mass loss measurements, Tafel polarisation curves and electrochemical impedance spectroscopy, obtaining an inhibition percentage of around 90% at a concentration of 1000 ppm of extract. Adsorption of the extract's components on the surface of the steel followed the Langmuir adsorption isotherm model, implying a physisorption mechanism based on thermodynamic parameters and from the ΔG 0 ads value, which was calculated at -15.16 KJ/mol. SEM was used to verify the presence of an organic layer on the steel, corroborating the adsorption of the organic components from the extract blocking active sites on the steel.

Tropical/non‐tropical marine environments impact on the behaviour of carbon steel and galvanised steel

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“…All the connections on the two‐layer network are in a forward direction. As long as the neurons on the hidden layer have radial and nonlinear transfer functions, the neurons on the output layer make linear combinations with the corresponding activation of neurons on the hidden layer …”

“…ANNs are defined as a set of artificial neurons distributed in accordance with a determined topology. [27][28][29] Artificial neural networks are widely used in a large variety of disciplines and applications. One of the factors that make neural networks so attractive is their capacity to characterise nonlinear functions.…”

“…As long as the neurons on the hidden layer have radial and nonlinear transfer functions, the neurons on the output layer make linear combinations with the corresponding activation of neurons on the hidden layer. [27][28][29] 3 | RESULTS AND DISCUSSION…”

“…General structure of an artificial neuron [27][28] composed of a fringe of coastline along with western edge of the Southern Cone, extending from latitude 17°29′57″ S to 56°32′12″ S, between its Pacific Ocean coastline to the highest peak of the Andes mountains. Northern Chile is characterised by abundant morning fog and the absence of precipitation (3 mm a year on average) due to the cold Humboldt Current, and is classified as a desert climate with abundant cloud cover that dissipates during the day, with average temperatures of 19°C.…”