scholarly journals Thermodynamic and Kinetic Parameters of Methanolic Extract of Leaves of Cochlospermum Tinctorium as Eco-friendly Inhibitor for Corrosion of Mild Steel in HCL Medium

2015 ◽  
Vol 6 ◽  
pp. 83-90
Author(s):  
G I Adams ◽  
S O Adejo ◽  
J U Ahile ◽  
J A Gbertyo ◽  
J O Ogbodo

Thermodynamic, kinetic and adsorptive parameters of methanolic extract of leaves of Cochlospermum tinctorium as eco-friendly inhibitor for the corrosion of mild steel in HCl medium were evaluated through the weight loss method at 303 K and 311 K. The inhibition efficiency, %IE, increased with increase in extract concentration, but found to be better at 303 K than 311 K. The decrease in %IE with increase in temperature with the average value of 81.88 kJ/mol for activation energy, E a , and the values of free energy, ÄG, for the adsorption process are all supportive of physical adsorption mechanism. The values of heat of adsorption, Q ads,, are all negative, an indication that the adsorption process was exothermal. The half-life, t 1/2 , value increased with increase in inhibitor concentration and low at high higher, implying the inhibitor performance increased with increase in the extract concentration and decreased with rise in temperature. The data best fitted the Langmuir adsorption isotherm.

2008 ◽  
Vol 5 (2) ◽  
pp. 355-364 ◽  
Author(s):  
S. A. Umoren ◽  
I. B. Obot ◽  
E. E. Ebenso

The anti-corrosive effect of Pachylobus edulis exudate gum in combination with halides ions (Cl–, Br–and I–) for aluminium corrosion in HCl was studied at temperature range of 30-60°C using weight loss method. Results obtained showed that the naturally occurring exudate gum acts as an inhibitor for aluminium corrosion in acidic environment. Inhibition efficiency (%I) increases with increase in concentration of the exudate gum and synergistically increased to a considerable extent on the addition of the halide ions. The increase in inhibition efficiency (%I) and surface coverage (θ) in the presence of the halides was found to be in the order I–> Br–> Cl–which indicates that the radii as well as electronegativity of the halide ions play a significant role in the adsorption process. Pachylobus edulis exudate gum obeys Temkin adsorption isotherm. Phenomenon of physical adsorption is proposed from the values of kinetic and thermodynamic parameters obtained. The values of synergism parameter (S1) obtained for the halides are greater than unity suggesting that the enhanced inhibition efficiency of the P. edulis caused by the addition of the halide ions is only due to synergistic effect.


Author(s):  
Nyirimbibi Daniela Kalisa ◽  
Theonestea Muhizi ◽  
Jean Jacques Yvesa Niyotwizera ◽  
Jean Baptistea Barutwanayo ◽  
Jean Boscoa Nkuranga

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


2019 ◽  
Vol 35 (3) ◽  
pp. 1073-1079
Author(s):  
R. Jeevitha ◽  
M. J. Judithaa ◽  
T. Sunder Selwyn ◽  
A. P. Srikanth

The eco-friendly inhibitor is used to safeguard the environment as well as the industrial equipments where corrosive acids are used for cleaning purposes. The inhibition ability of Atalantia monophylla leaves (AML) on the deterioration of mild steel (MS) in acid medium was investigated by mass loss and electrochemical techniques. The inhibition capability raised with rising the concentration of AML extract from weight loss method, immersion period and temperature studies. Electrochemical studies data explained in which AML inhibitor performed like cathodic and anodic type of inhibitor in corrosive medium. The adsorbed layer formed on the metal due to AML extract fulfilled the Langmuir adsorption isotherm. The formation of the protective film on the MS surface was acknowledged by SEM, EDS and FTIR. All the techniques proved AML as acceptable corrosion inhibitor in 1N HCl medium.


2020 ◽  
Vol 45 (5) ◽  
Author(s):  
Ali Bilar ◽  
Benedict Christopher

The corrosion inhibition of mild steel in 0.5M H2SO4 and 1M HCl by leave extract of eucalyptus was studied using gravimetric (weight loss) method at various temperature. The results obtained showed that the efficiency of inhibition increases with increase in the extract concentrations and decreases with rise in temperature. The adsorption of plant extract on the mild steels was found to obey Longmuir adsorption isotherm. This could be due to physical adsorption of cation species on the metal surface.


2016 ◽  
Vol 12 (1) ◽  
pp. 27
Author(s):  
Maria Erna ◽  
Emriadi Emriadi ◽  
Admin Alif ◽  
Syukri Arief

The thermodynamic properties and characterizations of corrosion inhibition of chitosan nano-particles on the surface of mild steel in peat water media had been studied using weight loss method at temperatures of 30 - 50 <sup>o</sup>C. Steel surfaces were characterized by FT-IR spectra and SEM-EDS morphology photos. The research found that the value of DG<sup>o </sup>approaching -40 kJmol<sup>-</sup><sup>1</sup>. The negative value of Gibbs free energy shows that the adsorption of inhibitor molecules on the surface of mild steel was achemisorption and it occurred spontaneously. Meanwhile, the values of DH<sup>o </sup>is also negative confirming that the adsoprtion of inhibitor molecules is an exothermic process. The value of DS<sup>o </sup>obtained is positive, it indicates hat the inhibitor molecules were adsorbed spontaneously on the mild steel surface. The analysis on mild steel surfaces hows that the nano-particle chitosan was adsorbed on the steel surface to form the complex compounds.


RSC Advances ◽  
2019 ◽  
Vol 9 (70) ◽  
pp. 40997-41009 ◽  
Author(s):  
Dongyi Li ◽  
Panpan Zhang ◽  
Xinyu Guo ◽  
Xiaowei Zhao ◽  
Ying Xu

The inhibitory effect of radish leaf extract (RLE) on mild steel corrosion in 0.5 M H2SO4 was studied by the weight loss method and the electrochemical method.


2019 ◽  
Vol 31 (12) ◽  
pp. 2745-2752
Author(s):  
P.K. Neena ◽  
N. Poongothai ◽  
P.R. Abhirami

This work aims to find the inhibition efficiency of Alstonia schoalris leaves on mild steel in 1N HCl medium. Corrosion monitoring was done using weight loss method, potentiodynamic polarization studies like Tafel and impedance studies and the results shows that the inhibitor acts well on mild steel in acidic medium. Polarization studies show that the inhibitor behaves like a mixed type. The inhibitor was characterized using FTIR which showed the presence of hetero atoms in the inhibitor molecule that get adsorbed on metal surface and provided better efficiency and that was proven by different adsorption isotherm. Zeta potential showed the stability of particle in the medium. Surface analysis of specimen was studied using FESEM, EDX and contact angle measurements. The analysis showed that the surface exposed to inhibitor is less corroded and contact angle measurement showed hydrophilic nature of the surface. Here, the inhibition is attributed to the electrostatic interaction of active sites on metal and inhibitor.


Author(s):  
Akindele Okewale ◽  
Felix Omoruwuo

The influence of neem leaf extract on corrosion inhibition of mild steel in 0.1 M HCl solution was studied using the weight loss method. Neem leaf extract which contains the double bond, carbonyl groups, and aromatic rings functional group as shown by the GCMS, phytochemical test, and FTIR analyses is one of the good natural plant extract that can be used as corrosion inhibitor. The weight loss on surface of mild steel at various inhibitor concentrations was determined. The highest inhibition efficiency of 93.24% was achieved using the neem leaf extract as corrosion inhibitor. Adsorption mechanism was investigated using Langmuir, Temkin, and Freundlich isotherms. Inhibitor adherence on the mild steel surface was spontaneous with the negative Gibb’s free energy value obtained. The mixed type adsorption mechanism (physisorption and chemisorption) is proposed for the inhibitor adsorption on mild steel surface. The inhibitor was adsorbed on the mild steel surface through adsorption of the phytochemical components on the surface of mild steel which protects the metal surface from corroding. The corrosion rate decreases from 0.001 to 0.0002MPY with increase in inhibitor concentrations and exposure time.


2010 ◽  
Vol 7 (3) ◽  
pp. 942-946 ◽  
Author(s):  
B. Anand ◽  
V. Balasubramanian

The inhibition of corrosion of mild steel usingPiper nigrumL in different acid medium by weight loss method was investigated. The corrosion inhibition was studied in hydrochloric acid and sulphuric acid by weight loss method at different time interval at room temperature. The result showed that the corrosion inhibition efficiency of this compound was found to vary with different time interval and different acid concentration. Also, it was found that the corrosion inhibition behavior ofPiper nigrumL is greater in sulphuric acid than hydrochloric acid. So,Piper nigrumL can be used as a good inhibitor for preventing mild steel material.


Author(s):  
Haruna, A. ◽  
Rumah, M.M. ◽  
Sani, U. ◽  
Ibrahim, A.K.

Schiff base derived from the reaction of 2-amino phenol and 2-hydroxy-1-naphthaldehyde and its Co (II), and Mn (II) complexes have been synthesized and characterized by solubility test, melting point/ decomposition temperatures, molar conductance, IR and magnetic susceptibility. The number of ligands coordinated to the metal ion was determined using Job’s method of continuous variation. Their molar conductance values indicate that all the complexes are non-electrolytes. Magnetic moment values of the complexes showed that both Mn (II) and Co (II) are paramagnetic. The spectroscopic data of metal complexes indicated that the metal ions are complexed with azomethine nitrogen and deprotonated oxygen atom. Corrosion inhibition of the schiff base and Mn (II) and Co (II) complexes were evaluated using the weight loss method in a 0.1MHCl solution for copper metal. The inhibition efficiency increased with increasing inhibitors concentration. The negative values of Gibb’s free energy of adsorption (ΔGads) confirmed the spontaneity and physical adsorption of the inhibition process which is inconsistent with Langmuir adsorption isotherm.


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