scholarly journals Inhibiting Properties of Morpholine as Corrosion Inhibitor for Mild Steel in 2N Sulphuric Acid and Phosphoric Acid Medium

2012 ◽  
Vol 9 (4) ◽  
pp. 2213-2225 ◽  
Author(s):  
K. Jayanthi ◽  
M. Sivaraju ◽  
K. Kannan
Keyword(s):  
Phosphoric Acid ◽  
Mild Steel ◽  
Sulphuric Acid ◽  
Inhibition Efficiency ◽  
Free Energy Of Adsorption ◽  
Enthalpy Of Adsorption ◽  
Inhibition Effect ◽  
Temkin's Adsorption Isotherm ◽  
Entropy Of Adsorption ◽  
Mixed Type Inhibitor

The inhibition effect of morpholine on the corrosion of mild steel in 2N sulphuric acid and phosphoric acid has been studied by mass loss and polarization techniques between 302K and 333K. The inhibition efficiency increased with increase in concentration. The corrosion rate increased with increase in temperature and decreased with increase in concentration of inhibitor compared to blank. The adsorption of inhibitor on the mild steel surface has been found to obey Temkin's adsorption isotherm. Potentiostatic polarization results reveal that morpholine act as mixed type inhibitor. The values of activation energy (Ea), free energy of adsorption (∆Gads), enthalpy of adsorption (∆H), and entropy of adsorption (∆S) were also calculated.

Inhibition Effect of N-Octyl-2-Pyrrolidonium Chloride on the Corrosion of Mild Steel in Acidic Medium

2013 ◽  
Vol 634-638 ◽  
pp. 651-654
Author(s):  
Zi Chong Zhuang ◽  
Bao Hua Huang ◽  
Jun Liu ◽  
Yu Jing Lu ◽  
Zhan Chang Pan ◽  
...  
Keyword(s):  
Weight Loss ◽  
Mild Steel ◽  
Acidic Medium ◽  
Mixed Type ◽  
Inhibition Efficiency ◽  
Electrochemical Techniques ◽  
Inhibition Mechanism ◽  
Inhibition Effect ◽  
Hcl Solution ◽  
Mixed Type Inhibitor

A new ionic liquid, N-octyl-2-pyrrolidonium chloride (NOPC), were synthesized and evaluated as inhibitors for mild steel (Q235) corrosion in 1 mol/L HCl. The adsorption behavior and corrosion inhibition mechanism of NOPC for mild steel in HCl solution were investigated by using weight loss measurements, electrochemical techniques, and SEM. The inhibition efficiency increases with the increasing concentration of NOPC in 1 mol/L HCl and decreases as the temperature increases. The results indicate that NOPC is able to function as a mixed type inhibitor.

scholarly journals Investigation of Inhibition Effect of Acrylic acid on C-Steel Corrosion in Sulfuric Acid Solutions

2010 ◽  
Vol 6 (3) ◽  
pp. 1059-1071
Author(s):  
S. Abd El Wanees ◽  
Salah Salem ◽  
A.M.A A Shehata ◽  
M. Abd El Azim
Keyword(s):  
Acrylic Acid ◽  
Inhibition Efficiency ◽  
Steel Corrosion ◽  
Polymeric Film ◽  
Acid Solutions ◽  
Inhibition Effect ◽  
Galvanostatic Polarization ◽  
Temkin's Adsorption Isotherm ◽  
Sulfuric Acid Solutions ◽  
Mixed Type Inhibitor

Acrylic acid was tested as a corrosion inhibitor for C-steel in 0.5 M H2SO4 using gasometry, weight loss, and galvanostatic polarization techniques. Polymeric film is built up by cyclic voltammetry technique. The potentiodynamic polarization is used to examine the inhibition effect with the coated polymeric film. The data obtained from the different techniques coincide in that acrylic acid is a good mixed-type inhibitor. The inhibition process is based on the adsorption of acrylic acid on the surface of C-steel according to Temkin’s adsorption isotherm. The inhibition efficiency increases with inhibitor concentration and decreases with temperature. The thermodynamic parameters ΔE, ΔH*, ΔS*, and ΔG*ads were calculated to elaborate the mechanism of corrosion inhibition.

scholarly journals Inhibitive Effect of Costus afer Extracts on Mild Steel Corrosion in Acidic Medium

2016 ◽  
Vol 7 ◽  
pp. 60-67
Author(s):  
Lebe A. Nnanna ◽  
Wisdom O. John ◽  
Tochukwu E. Esihe ◽  
Kelechi C. Denkoro ◽  
Victor I. Okparaku ◽  
...  
Keyword(s):  
Mild Steel ◽  
Room Temperature ◽  
Inhibition Efficiency ◽  
Gravimetric Method ◽  
Steel Corrosion ◽  
Corrosion Process ◽  
Inhibition Effect ◽  
A Value ◽  
Mild Steel Corrosion ◽  
Costus Afer

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.

The corrosion inhibition of carbon steel in 5 per cent HCl by Momordica charantia extract

2014 ◽  
Vol 61 (4) ◽  
pp. 255-260 ◽  
Author(s):  
Xie Xuejun* ◽  
Xiao Peng* ◽  
He Jie ◽  
Xiao Wen ◽  
Fu Qiang ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Mixed Type ◽  
Inhibition Efficiency ◽  
Xps Analysis ◽  
Content Type ◽  
Isotherm Equation ◽  
Inhibition Effect ◽  
Langmuir Isotherm Equation ◽  
Ir Analysis ◽  
Mixed Type Inhibitor

Purpose – To study the inhibition effect and mechanism of the Momordica charantia extract (BM) to 20 A carbon steel in 5 per cent HCl. Design/methodology/approach – The weight loss, polarization curve, infrared spectrum (IR) analysis and X-ray photoelectron spectrum (XPS) analysis were carefully investigated to indicate the inhibition effect and mechanism of the BM to 20 A carbon steel in 5 per cent HCl. Findings – BM was composed of C, N and O. Functional groups such as N–H and C=O were found in BM. The inhibition efficiency increased with the increasing concentration of BM. BM behaved as a mixed-type inhibitor, and the inhibition of BM to 20 A carbon steel might be its adsorption through the coordinate covalent bonding among the lone pair electrons of N and O and the empty 3d orbits of Fe, and the adsorption on the surface of 20 A carbon steel obeyed the Langmuir isotherm equation. Research limitations/implications – The inhibition of the BM to 20 A carbon steel in 5 per cent HCl. Practical implications – BM could be used in 5 per cent HCl to prevent 20 A carbon steel from corrosion. Social implications – BM could be used in the chemical cleaning of the boilers to prevent the thermal equipments from corrosion. Originality/value – The inhibition effect and mechanism of the BM to 20 A carbon steel were studied by the weight loss, polarization curve, IR analysis and XPS analysis. BM was composed of C, N and O. Functional groups such as N–H and C=O were found in BM. BM behaved as a mixed-type inhibitor. The inhibition efficiency increased with the increasing concentration of BM, and the adsorption on the surface of 20 A carbon steel obeyed the Langmuir isotherm equation.

INVESTIGATION OF ADSORPTION AND INHIBITIVE EFFECT OF CALIXARENE DERIVATIVE NEWLY SYNTHESIZED TOWARDS C38 STEEL IN MOLAR HCl

2009 ◽  
Vol 16 (03) ◽  
pp. 401-406 ◽  
Author(s):  
R. SOUANE ◽  
M. KADDOURI ◽  
M. BOUKLAH ◽  
N. CHERIAA ◽  
B. HAMMOUTI ◽  
...  
Keyword(s):  
Weight Loss ◽  
Inhibition Efficiency ◽  
Langmuir Adsorption Isotherm ◽  
Enthalpy Of Adsorption ◽  
Langmuir Adsorption ◽  
Corrosion Phenomenon ◽  
Calixarene Derivative ◽  
Current Densities ◽  
C38 Steel ◽  
Mixed Type Inhibitor

The focus of this study is to synthesize a new calixarene derivative namely calix[6]arene (C21) and to test its performance as corrosion inhibitor of C38 steel in molar HCl at 308 K. Polarization and weight loss measurements were used. Weight loss tests show that C21 retards until to stop corrosion phenomenon at 5 × 10-5 M . C21 is an excellent inhibitor and its inhibition efficiency increases with its concentration to reach 100% since 5 × 10-5 M . Polarization curves revealed that C21 affects both cathodic and anodic domains by decreasing current densities and then it may be classified as a mixed type inhibitor. The calixarene tested is adsorbed on the surface according to the Langmuir adsorption isotherm. Free enthalpy of adsorption reveals that C21 acts from chemisorption onto the steel surface.

scholarly journals SYNTHESIS AND EVALUATION OF ETHYL (4-(N-(THIAZOL-2-YL) SULFAMOYL) PHENYL)CARBAMATE (TSPC) AS A CORROSION INHIBITOR FOR MILD STEEL IN 0.1M HCL

2016 ◽  
Vol 11 (2) ◽  
pp. 3441-3451 ◽  
Author(s):  
A. M. El-Shamy ◽  
M. F. Shehata ◽  
Samir T. Gaballah ◽  
Eman A. Elhefny
Keyword(s):  
Mild Steel ◽  
Corrosion Inhibitor ◽  
Room Temperature ◽  
Open Circuit Potential ◽  
Inhibition Efficiency ◽  
Electrochemical Techniques ◽  
Open Circuit ◽  
Free Energy Of Adsorption ◽  
Langmuir Adsorption ◽  
Gibb’S Free Energy

Laboratory synthesized ethyl (4-(N-(thiazol-2-yl)sulfamoyl)phenyl)carbamate (TSPC), characterized by 1H NMR spectroscopy, was evaluated as corrosion inhibitor of mild steel in 0.1M HCl using electrochemical techniques. Open circuit potential, potentiodynamic polarization and impedance spectroscopy were used to evaluate the inhibition efficiency of (TSPC) at various concentrations. The obtained electrochemical data indicated that (TSPC) acts as moderate corrosion inhibitor for mild steel in acidic media. It is found that the inhibition efficiency increases with the concentration of the inhibitor till 400ppm. The adsorption isotherm involving physisorption of (TSPC) at room temperature and the experimental data complied to the Langmuir adsorption isotherms and the negative values of the Gibb’s free energy of adsorption obtained suggested that inhibitor molecules have been spontaneously adsorbed onto the mild steel surface.

scholarly journals Natural Polymer of Iraqi Apricot Tree Gum as a Novel Corrosion Inhibitor for Mild Steel in 1 M HCl Solution

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
I. M. Alwaan ◽  
Fouad Kadhim Mahdi
Keyword(s):  
Weight Loss ◽  
Mild Steel ◽  
Polymer Concentration ◽  
Natural Polymer ◽  
Free Energy Of Adsorption ◽  
Adsorption Enthalpy ◽  
Enthalpy Of Adsorption ◽  
Weight Loss Method ◽  
Loss Method ◽  
Apricot Tree

Corrosion inhibition of mild steel in 1 M hydrochloric acid using Iraqi apricot tree gum Arabic as natural polymer was studied. The weight loss method was used to predict the efficiency of the inhibitor on corrosion of mild steel in a temperature range of 17–40°C. The FTIR result of natural polymer revealed that the C=O and O-H groups were found in the structure of the natural polymer. The results of weight loss method showed that the inhibition efficiency (I%) increased with the increase in both the natural polymer concentration and the temperature; therefore, chemical adsorption mechanism was suggested in this system. The different mathematical models of the adsorption isotherms were studied and the results revealed that natural polymer was found to obey Temkin, Langmuir, and Freundlich adsorption isotherm. The activation energy of adsorption, enthalpy of adsorption, and entropy of adsorption were obtained for different concentrations of natural polymer (0, 0.1, 0.2, and 0.3 g/L) and the results showed that the thermodynamic properties decreased with the loading of a natural polymer. Gibbs free energy of adsorption results was a minus value that led to the conclusion of the spontaneous adsorption of the natural polymer in this system.

The experimental and quantum chemical investigation for two isomeric compounds as aminopyrazine and 2-amino-pyrimidine against mild steel corrosion

2016 ◽  
Vol 63 (5) ◽  
pp. 369-376 ◽  
Author(s):  
Basak Dogru Mert ◽  
Mehmet Erman Mert ◽  
Gülfeza Kardas ◽  
Birgül Yazici
Keyword(s):  
Mild Steel ◽  
Molecular Orbital ◽  
Density Functional ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Molecular Geometry ◽  
Orbital Energy ◽  
Content Type ◽  
Inhibition Effect ◽  
Amino Pyrimidine

Purpose The purpose of this paper is to investigate the adsorption and corrosion inhibition of two isomeric compounds (C4H5N3) as aminopyrazine (AP) and 2-amino-pyrimidine (2AP) on mild steel (MS) in 0.5 M HCl. The study was a trial to combine experimental and modelling studies and research effect of molecular geometry on inhibition effect of inhibitor molecules. Design/methodology/approach The thermodynamic, kinetic and quantum parameters were determined. The electrochemical impedance spectroscopy and anodic polarisation measurements were obtained. The scanning electron microscope was used for monitoring electrode surface. The highest occupied molecular orbital, energy of the lowest unoccupied molecular orbital, Mulliken and natural bonding orbital charges on the backbone atoms, absolute electronegativity, absolute hardness were calculated by density functional theory (DFT)/B3LYP/6-311G (++ d,p). Findings Results showed that AP and 2AP suppressed the corrosion rate of MS. The corrosion current values were 0.530, 0.050 and 0.016 mA cm-2 in HCl, AP and 2AP containing HCl solutions, respectively. It was illustrated with the blocked fraction of the MS surface by adsorption of inhibitors which obeyed the Langmuir isotherm. The inhibition efficiency follows the order: 2AP > AP which is in agreement with experimental and quantum results. Originality/value This paper provides lay a bridge on the molecular geometry and inhibition efficiency by electrochemical tests and modelling study. The inhibition effect of AP and 2AP has not been compared with each other, neither experimentally nor theoretically. This study put forward possible application of 2AP as corrosion inhibitor especially for closed-circuit systems.

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