Experimental and computational mediated illustration of effect of different substituents on adsorption tendency of phthalazinone derivatives on mild steel surface in acidic medium

2020 ◽  
Vol 305 ◽  
pp. 112844 ◽  
Author(s):  
Motsie E. Mashuga ◽  
Lukman O. Olasunkanmi ◽  
Chandrabhan Verma ◽  
El-Sayed M. Sherif ◽  
Eno E. Ebenso
Keyword(s):  
Mild Steel ◽  
Acidic Medium ◽  
Steel Surface ◽  
Mild Steel Surface

scholarly journals Kinetics and Thermodynamics Investigations on Corrosion Inhibiting Properties of Coffee Husks Extract on Mild Steel in Acidic Medium

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Nyirimbibi Daniela Kalisa ◽  
Theonestea Muhizi ◽  
Jean Jacques Yvesa Niyotwizera ◽  
Jean Baptistea Barutwanayo ◽  
Jean Boscoa Nkuranga
Keyword(s):  
Phenolic Compounds ◽  
Mild Steel ◽  
Acidic Medium ◽  
Steel Surface ◽  
Inhibition Efficiency ◽  
Physical Adsorption ◽  
Mild Steel Surface ◽  
Ionic Dissociation ◽  
Weight Loss Method ◽  
Loss Method

In this study, the use of green corrosion inhibitors extracted from coffee husks was investigated on mild steel materials in acidic medium. Phenolic compounds from coffee husks were extracted using acetone solvent, characterised and investigated for their corrosion inhibiting properties. The FTIR and 1H-NMR technique were carried out to characterise the present phenolic compounds extracted from purified coffee husks. The corrosion inhibition efficiency of phenolic compounds from coffee husks extract on mild steel in 1.0 M HCl was evaluated by using weight loss method. The obtained results showed that corrosion rates decreased with the increase of inhibitor concentration, temperature and immersion time. The  optimum inhibition efficiency of 86.5% at 25 ºC was obtained with a concentration of 400 mg/L (400 ppm) of coffee husks extract in two hours of experiment. The observed inhibition efficiency was attributed to the physical adsorption mechanism of phenolic compounds on mild steel surface through charged ion formation from protonation of lone pairs of oxygen in phenol or ionic dissociation of carboxylic acid functional group that formed a charged layer over mild steel surface. Furthermore, it was pointed out that the adsorption process obeyed the Langmuir adsorption  isotherm model at all investigated temperatures between 25 and 40 ºC. Keywords: Corrosion inhibitor, phenolic compounds, coffee husks extract, mild steel, adsorption

Corrosion Inhibition of Mild Steel by Electrodeposited Poly(M-Aminophenol) Coating

2021 ◽  
Vol 317 ◽  
pp. 498-505
Author(s):  
Sabrina M. Yahaya ◽  
Mohamad Kamal Harun ◽  
Ismaliza Ismail ◽  
Rosmamuhamadani Ramli
Keyword(s):  
Mild Steel ◽  
Steel Surface ◽  
Electrochemical Impedance ◽  
Impedance Measurement ◽  
Barrier Properties ◽  
Electrical Circuit ◽  
Significant Drop ◽  
Mild Steel Surface ◽  
Barrier Resistance ◽  
And Performance

In this study, poly(m-aminophenol) (PMAP) coating was electrochemically synthesized by cyclic voltammetry (CV) on mild steel surface to investigate the effects of its barrier protection within the scope of its electrochemical impedance towards further oxidation of the mild steel substrates. The developed PMAP coating were characterized by Fourier Transform Infrared (FTIR) spectroscopy and Field Emission Scanning Electron Microscopy (FESEM). The barrier resistance ability of PMAP coating towards corrosion of mild steel was determined in 0.5 M aqueous sodium chloride solution (NaCl) at various immersion times by the electrochemical impedance spectroscopy (EIS). The barrier properties were interpreted through impedance measurement using Nyquist and Bode plots. Equivalent electrical circuit models derived from the plots were employed to describe the coating barrier behaviour and performance. Data obtained showed that, the oxidation peak of PMAP coating were observed at potential +1.0 V (Ag/AgCl). The micrograph of FESEM indicates the formation of a dense and continous PMAP coatings. In FTIR analyses, the presence of peak around 1082 cm-1 ascribed to C–O–C etheric linkage which supported the formation of electro polymerized PMAP coating on mild steel surface. EIS measurement revealed that, PMAP coatings experienced a significant drop in total impedance values with time followed by the development of an electrochemical reactions on coating/metal interface, which indicates the gradual degradation of the barrier resistance ability of the PMAP coatings.

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