scholarly journals Inhibition behaviour of mild steel by three new benzaldehyde thiosemicarbazone derivatives in 0.5 M H 2 SO 4 : experimental and computational study

2019 ◽  
Vol 6 (8) ◽  
pp. 190192
Author(s):  
H. H. Zhang ◽  
C. K. Qin ◽  
Y. Chen ◽  
Z. Zhang

Three new benzaldehyde thiosemicarbazone derivatives namely benzaldehyde thiosemicarbazone (BST), 4-carboxyl benzaldehyde thiosemicarbazone (PBST) and 2-carboxyl benzaldehyde thiosemicarbazone (OCT) were synthesized and their inhibition effects on mild steel corrosion in 0.5 M H 2 SO 4 solution were studied systematically using gravimetric and electrochemical measurements. Weight loss results revealed that PBST exhibited the highest inhibition efficiency of 96.6% among the investigated compounds when the concentration was 300 µM. The analysis of polarization curves indicated that the three benzaldehyde thiosemicarbazone derivatives acted as mixed type inhibitors and PBST and OCT predominantly anodic. The adsorption process of all these benzaldehyde thiosemicarbazone derivatives on Q235 steel surface in 0.5 M H 2 SO 4 solution conformed to Langmuir adsorption isotherm. Scanning electron microscopy was conducted to show the presence of benzaldehyde thiosemicarbazone derivatives on Q235 mild steel surface. The results of theoretical calculations were in good agreement with that of experimental measurements.

2021 ◽  
Vol 11 (2) ◽  
pp. 3509-3512

The temperature effect of 4-ethyl-1-(4-oxo-4-phenylbutanoyl)thiosemicarbazide (EOPT) on the mild steel corrosion in 1 M HCl solution was studied by gravimetric techniques at temperatures varying from 303 to 333 K. The investigated inhibitor concentrations were started from 100 ppm and ended with 500 ppm. The inhibition efficiency increased with the increase of the concentration of the inhibitor and reached 96.1% with the concentration of 500 ppm at 303 K and decreased to 66.3% at 333 K. Moreover, the inhibition efficiencies decreased with the temperature increase for both acids. Using the Langmuir adsorption isotherm for the adsorption of this inhibitor on the mild steel surface was determined. EOPT was found to be an efficient corrosion inhibitor due to its structural molecules, which contain sulfur, nitrogen, and oxygen, hetero atoms an addition to the aromatic ring.


Author(s):  
Inemesit A. Akpan ◽  
Okon U. Abakedi ◽  
Mfon A. James

Telfairia occidentalis rind extract has been studied as a potential green inhibitor for mild steel corrosion in 1 M H2SO4 using weight loss and hydrogen evolution methods. The results of the investigation reveal that Telfairia occidentalis rind extract is a good inhibitor of mild steel corrosion in sulphuric acid solution. The inhibition efficiency increases with increase in rind extract concentration but decreases with increase in temperature. The calculated thermodynamic parameters reveal that the corrosion inhibition process was endothermic and spontaneous. Physical adsorption has been proposed for the adsorption of Telfairia occidentalis rind extract onto mild steel surface. The adsorption of the extract on mild steel surface obeys the Langmuir adsorption isotherm. 


Author(s):  
Lebe A. Nnanna ◽  
Wisdom O. John ◽  
Tochukwu E. Esihe ◽  
Kelechi C. Denkoro ◽  
Victor I. Okparaku ◽  
...  

Inhibition effect of Costusafer on mild steel in 0.5 M HCl was studied using gravimetric method at room temperature. It was found out that Costusafer inhibited the corrosion of mild steel in the acidic environment and that the efficiency of inhibition increased as the concentration of the inhibitor in the environment increased. The data was used to test different isotherms and it suited the Langmuir isotherm. A value of -15.995 kJmol-1 was gotten for the ∆Goads. This value showed that the extracts of Costusafer inhibited the corrosion process through physiosorption mechanism. The high value of inhibition efficiency of the extract as the concentration increased in rationalized in terms of the increase in herteroatoms, saponnins and tannins which are present in the extract.


Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 27
Author(s):  
Shaimaa B. Al-Bghdadi ◽  
Mahdi M. Hanoon ◽  
Jafer F. Odah ◽  
Lina M. Shaker ◽  
Ahmed A. Al-Amiery

A New benzylidene derivative namely benzylidene-5-phenyl-1,3,4-thiadiazol-2-amine (BPTA), was successfully synthesized and characterized using Fourier Transform Infrared Spectroscopy, Nuclear Magnetic Resonance and elemental analysis (CHN) techniques. The inhibition efficiency of BPTA on mild steel corrosion in 1.0 N HCl was tested at various temperatures. The methodological work was achieved by gravimetric method complemented with morphological investigation. The concentrations of inhibitor were 0.1, 0.2, 0.3, 0.4 and 0.5 mM at the temperatures 303, 313, 323 and 333 K. The BPTA, molecules as become superior corrosion inhibitor with 92% inhibition efficiency of mild steel coupon in the acidic environment. The inhibition efficiency increased with increasing concentrations of BPTA and the excellent efficiency was performed with the 0.5 mM concentration and followed with 0.4 mM. In acidic environment, the 0.5 and 0.4 mM gave the optimum performance with weight loss technique and scanning electron microscopy analysis. On the other hand, the inhibition efficiency decreased with the increase of temperature. Results of BPTA indicated mixed type inhibitor and the adsorption on the mild steels surface obeys the Langmuir adsorption isotherm. It was found that the BPTA performance depend on the concentration and the solution temperature. Quantum chemical calculations have been done to correlate the electronic characteristics of BPTA with the corrosive inhibitive impact. Experimental and theoretical results are in good agreement.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
M. K. Pavithra ◽  
T. V. Venkatesha ◽  
M. K. Punith Kumar

The corrosion inhibition effect of Rabeprazole sulfide (RS) on mild steel in 1 M hydrochloric acid (HCl) was investigated using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and chronoamperometric measurements. Protection efficiency of RS increases with the concentration and decreases with the rise in temperature. Adsorption of RS on mild steel surface in 1 M HCl follows Langmuir adsorption isotherm. The kinetic and thermodynamic parameters governing the adsorption process were calculated and discussed. The polarization results suggest that RS performed as an excellent mixed-type inhibitor for mild steel corrosion in 1 M HCl.


2011 ◽  
Vol 8 (s1) ◽  
pp. S53-S60 ◽  
Author(s):  
M. Vishnudevan

The inhibition efficiency of mild steel corrosion in HCl acidic solution containing various concentrations of mixed inhibitors were evaluated by conducting Tafel polarization and electrochemical impedance studies. The mixed inhibitors used in this present investigation were trisodium citrate and sodium benzoate. In this present investigation 0.01 N to 0.1 N concentrations of HCl was used at 30°C. Sodium benzoate present in the mixed inhibitive system enhanced the inhibition efficiency through chemisorptions. The maximum inhibition efficiency ( 95.4%) was obtained for the mixed inhibitive system containing 0.05 M citrate and 0.5 M benzoate in 0.1 N HCl.


Lubricants ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 93
Author(s):  
Ahmed A. Alamiery ◽  
Wan Nor Roslam Wan Isahak ◽  
Mohd S. Takriff

Gravimetric measurements were applied to study the inhibitory effect of 4-benzyl-1-(4-oxo-4-phenylbutanoyl)thiosemicarbazide (BOT) on the corrosion of mild steel in 1.0 M HCl. BOT has a good inhibitory efficacy of 92.5 percent at 500 ppm, according to weight loss results. The effect of inhibitor concentration on the mild corrosion behavior of steel was investigated and it was discovered that the higher the inhibitor concentration, the higher the damping efficiency. The results confirm that BOT is an effective corrosion inhibitor for mild steel in the presence of 1.0 M HCl. Furthermore, the higher protection efficiency with increasing temperature and the free energy value showed that BOT molecules participate in both chemisorption (coordination bonds between the active sites of BOT molecules and d-orbital of iron atoms) and physisorption (through the physical interactions on the mild steel surface). The adsorption mechanism on the mild steel surface obeys the Langmuir adsorption isotherm model. Quantum chemical calculations based on the DFT calculations were conducted on BOT. DFT calculations indicated that the protective efficacy of the tested inhibitor increased with the increase in energy of HOMO. The theoretical findings revealed that the broadly stretched linked functional groups (carbonyl and thionyl) and heteroatoms (sulfur, nitrogen and oxygen) in the structure of tested inhibitor molecules are responsible for the significant inhibitive performance, due to possible bonding with Fe atoms on the mild steel surface by donating electrons to the d-orbitals of Fe atoms. Both experimental and theoretical findings in the current investigation are in excellent harmony.


2016 ◽  
Vol 5 (4) ◽  
pp. 247
Author(s):  
Shubha H Natarj ◽  
Venkatesha T Venkatarangaiah ◽  
Anantha N Subbarao

<div><p><em>The present work demonstrated that corrosion inhibition efficiency of electrochemically generated organic coat is remarkably effective than self-assembled monolayer (SAM) generated by dip coating technique. Perfluorooctanoic Acid (PFOA) is used to modify mild steel surface for effective protection. Infrared reflection absorption spectroscopy and contact angle measurements substantiate the modification of mild steel surface and its effect on surface hydrophobicity. A comparison between electrochemical properties of PFOA SAM generated by dip coat method (DC-PFOA) and PFOA coat generated by electrochemical method (EC-PFOA) is presented. Electrochemical measurements reveal that the corrosion protection efficiency of EC-PFOA (91%) is much superior to DC-PFOA (28%). </em></p></div>


2016 ◽  
Vol 13 (2) ◽  
pp. 101-105
Author(s):  
Monikandon Sukumaran ◽  
Kesavan Devarayan

Steel corrosion inhibition in acidic and alkaline medium by ethanolic extract of Milletia pinnata is described in this study. The inhibitive behavior of the inhibitor is evaluated by weight loss measurements, adsorption isotherms, and thermochemical parameters. The inhibitor exhibited a maximum of 87% and 90.5% inhibition efficiency against steel corrosion in 0.5 M NaOH and 1.0 M H2SO4, respectively. The weight loss linearly fit to Langmuir adsorption isotherm with correlation coefficient value close to unity. The thermochemical parameters indicated for predominant physical adsorption of the inhibitor molecules on the steel surface.


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