Electrochemical Behaviourof Some Amino Acids as Corrosion Inhibitors for Mild Steel in Sweet Brine

Abstract

The effect of concentration and immersion time of phenylalanine (Phe), leucine (Leu) and valine (Val) for AISI 1018 in sweet brine was studied trough Electrochemical Impedance Spectroscopy (EIS), polarization resistance (Rp), Scanning Electronic Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) as an ecological and biodegradable alternative as corrosion inhibitors. Electrochemical results showed that amino acids are good corrosion inhibitors according to their charge transfer resistance improvement. The effect of immersion time on corrosion behavior was studied trough 24 h with amino acids concentration variation of 0, 10, 100 and 250 ppm. The preliminary results demonstrated that the three amino acids adsorb over metal surface following the Langmuir adsorption isotherm model, and tend to agglomerate in bulk within time. Keywords: Corrosion Inhibitors; Biodegradable; Amino acids; Sweet brine

Synthesis, characterization, and computational study of N‐protected amino acid inhibitors as well as assessment of corrosion resistance properties on mild steel in .5 M H2SO4 solution

“…The performance of L‐methionine anti‐corrosive nature was determined through electrochemical impedance spectroscopy (EIS) and Tafel tests that show its corrosive inhibition efficiency of about 97% and 95%, respectively. González et al find that amino acids can apply in the oil industry as eco‐friendly corrosion inhibitors for AISI 1018 in sweet brine 16 . Due to the protonation of the amino group, amino acids exhibit higher anti‐corrosive properties in neutral and acidic solutions.…”

“…Gonz alez et al find that amino acids can apply in the oil industry as eco-friendly corrosion inhibitors for AISI 1018 in sweet brine. 16 Due to the protonation of the amino group, amino acids exhibit higher anti-corrosive properties in neutral and acidic solutions. Phenylalanine shows 89% inhibition efficiency, more than leucine and valine.…”

Alkali salts of amino acids as alkaline additives for neutralization of acidic corrosion inhibitors

“…Amino acids have therefore been frequently used in the context of green chemistry (Shirini and Daneshvar 2016 ; Somorjai et al 2009 ; Yang et al 2016 ) and investigated as green acidic CIs (Verma et al 2021 , 2018 ). However, the anti-corrosive properties of amino acids at alkaline pH values are limited (Kasprzhitskii et al 2021 ; León González 2021 ; Ormellese et al 2009 ) and only selected amino phosphonic acids are used commercially as antiscalants and CIs mostly in combination with zinc salts (Moschona et al 2018 ). Anticorrosive properties of amino carboxylic acids in acidic media have also been found to be improved by addition of Lewis acids such as Zn 2+ or surfactants (Mobin et al 2017 ; Pech-Canul and Chi-Canul 1999 ; Zhang et al 2016 ).…”