Corrosion Inhibition by Flower Extracts - At a Glance

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Rajendran Susai ◽  
A Suriya Prabha ◽  
Vijaya N ◽  
Umasankareswari T ◽  
Krishnaveni A ◽  
...  

Flower extract are ecofriendly corrosion inhibitors. They have been used to control corrosion of mild steel, copper and aluminium in various media. The mechanistic aspects have been investigated by electrochemical studies such as polarisaiton study and AC impedance spectra. The protective film has been analysed by FTIR, SEM, EDX and AFM. The adsorption isotherms isotherms being obeyed are Langmuir, Temkin and Freundlich adsorption isotherms. The flowers extract primarily function as mixed type of inhibitors. The active principles mainly present in colored flowers are anthocyanins, and carotenoids. They contain polar groups such as hydroxyl, methoxy and ether. These ingredients coordinate with the metal ions on the metal surface through oxygen atom, benzene ring and conjugated double bonds. The protective film formed on the metal surface controls the corrosion process. Keywords: Corrosion Inhibition; Flower Extract; AFM; SEM; FTIR; Isotherms; Green Inhibitors

2021 ◽  
Vol 62 (3) ◽  
pp. 191-203
Author(s):  
Josephath Praveena ◽  
Somasundaram Gowri ◽  
Gunasekaran Nethravathi ◽  
Vincent Varsha ◽  
Arockiasamy Vieyana ◽  
...  

The corrosion resistance of SS 18/8 in natural sea water, in presence of an inhibitor named Thiourea-Zn2+ has been evaluated. Weight loss method, polarization study and AC impedance spectra have been employed to evaluate the corrosion resistance of SS 18/8 alloy in natural sea water, in presence of an inhibitor named Thiourea-Zn2+ system. Weight loss method reveals that Thiourea-Zn2+ system offers a maximum corrosion inhibition efficiency of 95% in controlling corrosion of SS 18/8 alloy in natural sea water. Synergism parameters are found to be greater than 1, confirming the synergistic effect existing between Thiourea-Zn2+. Adsorption of inhibitor molecules on the metal surface obey Langmuir adsorption isotherm. Polarisation study reveals that the inhibitors named Thiourea-Zn2+ system functions as mixed type of inhibitor. AC impedance spectra confirm the formation of a protective film on the metal surface. This formulation of Thiourea-Zn2+ may be used in cooling water systems where SS 18/8 alloy pipelines are used to carry sea water which is used as coolant. Also, Thiourea-Zn2+ coating can be given on SS 18/8 alloy to protect it from corrosion by sea water when SS 18/8 alloy is used as hull plates in ship industry.


2019 ◽  
Vol 7 (2) ◽  
pp. 72-77
Author(s):  
M.B. Geetha ◽  
◽  
J. Sathish ◽  
S. Rajendran ◽  
◽  
...  

The formulation consisting of 100 ppm Thiourea, 25 ppm Zn2+ and 250 ppm of L-Phenylalanine has 95% corrosion inhibition efficiency with a synergistic effect among Thiourea, L-Phenylalanine and Zn2+ ions. Polarization study shows that this formulation as a mixed inhibitor. FTIR spectra exposed the presence of Fe2+-Thiourea, Fe2+-L-Phenylalanine complex and Zn(OH)2 in protective film. AFM study confirmed the metal surface smoothness following engrossed in the inhibitor and the presence of formed protective film on the metal surface.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
C. Mary Anbarasi ◽  
Susai Rajendran

Inhibition of corrosion of carbon steel in dam water by hexanesulphonic acid as its sodium salt C6H13SO3Na (SHXS) in the absence and presence of a bivalent cation zinc ion (Zn2þ) has been investigated using weight loss method. Results of weight loss method indicate that inhibition efficiency (IE) increased with increase of inhibitor concentration. Polarization study reveals that SHXS-Zn2+ system controls the cathodic reaction predominantly. AC impedance spectra reveal that a protective film is formed on the metal surface. The nature of the metal surface has been analysed by Fourier Transform Infrared Spectroscopy (FTIR) and Atomic Force Microscopy (AFM).


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
V. Johnsirani ◽  
J. Sathiyabama ◽  
Susai Rajendran ◽  
A. Suriya Prabha

The inhibition efficiency (IE) of an aqueous extract of henna leaves in controlling corrosion of carbon steel in seawater has been evaluated by weight-loss method. The weight loss study reveals that the formulation consisting of 8 mL of henna extract (HE) and 25 ppm of Zn2+ has 94% inhibition efficiency in controlling corrosion of carbon steel in sea water. Polarization study reveals that HE and Zn2+ system functions as mixed type inhibitor. AC impedance spectra reveal that protective film is formed on the metal surface. The nature of the metal surface has been analysed by FTIR spectra, SEM, and AFM analysis.


2020 ◽  
Vol 4 (3) ◽  
pp. 154-161
Author(s):  
Anthony Victor Gambo

The effect of extract of Acacia Nolitica pod on the corrosion inhibition of LM 6 aluminium alloy in 1M NaOH was studied using weight loss, gasometric, and open circuit potential techniques. Corrosion rates were found to reduce in the presence of the inhibitor. The inhibition efficiency was found to increase with increase in the concentration of the inhibitor and decreased with increase in the temperature. Thermodynamic parameters showed that the adsorption of the inhibitor on the metal surface is a spontaneous process and that the adsorption was via a physisorption mechanism. The adsorption process fitted perfectly with the Langmuir adsorption isotherm indicating that the extract was strongly adsorbed on the aluminium alloy surface. Morphology of the surface was examined by scanning electron microscopy (SEM) in the absence and presence of 0.5%v/v of the used inhibitor which confirmed the existence of a protective film of inhibitor molecule on the metal surface.  


2020 ◽  
Vol 49 (1) ◽  
pp. 63-70
Author(s):  
Bhuvaneshwari Durvas Seshian ◽  
Bothi Raja Pandian ◽  
Umapathi Durai

Purpose The purpose of this study is to develop green/natural corrosion inhibitors. Adina cordifolia leaves extract (ACLE) was screened for its corrosion inhibition potential for mild steel (MS) corrosion in 0.5 M H2SO4 medium. Design/methodology/approach Adina cordifolia (AC) leaves were subjected to cold ethanol extraction and concentrated after refluxed with double distilled water. The resultant concentrate was screened for corrosion inhibition studies using sequence of standard corrosion monitoring techniques, namely, gravimetric analysis, electrochemical studies and scanning electron microscopy (SEM). Findings Gravimetric analysis provided evidence that the prepared ACLE showed dose dependent corrosion inhibition; impedance study revealed that the ACLE increases the charge transfer resistance and decreases double layer capacitance while polarization curves indicated that ACLE acts as a mixed-type inhibitor. Further studies over MS surface/test solutions through SEM and Fourier-Transform Infrared spectroscopy evident the formation of ACLE protective film protects MS. Practical implications AC’s methanol extract developed in this work can be used as a green corrosion inhibitor over industrial applications. Originality/value For the first time, AC leaves were tested as corrosion inhibitors for MS corrosion in 0.5 M H2SO4 medium. The results evidenced that ACLE will be a promising corrosion inhibitor, which could be usable in industries as a green corrosion inhibitor.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
K. Rajam ◽  
S. Rajendran ◽  
N. Nazeera Banu

The inhibition efficiency (IE) of caffeine in controlling corrosion of carbon steel in well water in the absence and presence of Zn2+has been evaluated by mass loss method. The formulation, consisting of 200 ppm of caffeine and 50 ppm Zn2+, offers 82% inhibition efficiency to carbon steel immersed in well water. Addition of malic acid increases inhibition efficiency of the caffeine-Zn2+system. The inhibition efficiency of caffeine-Zn2+and caffeine-Zn2+-malic acid system decreases with the increase in immersion period and increases with the increase in pH from 3 to 11. AC impedance spectra, SEM micrographs, and AFM studies reveal the formation of protective film on the metal surface. The film is found to be UV fluorescent.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
S. Gowri ◽  
J. Sathiyabama ◽  
S. Rajendran

The inhibition efficiency of L-Arginine-Zn2+system in controlling corrosion of carbon steel in sea water has been evaluated by the weight-loss method. The formulation consisting of 250 ppm of L-Arginine and 25 ppm of Zn2+has 91% IE. A synergistic effect exists between L-Arginine and Zn2+. Polarization study reveals that the L-Arginine-Zn2+system functions as an anodic inhibitor and the formulation controls the anodic reaction predominantly. AC impedance spectra reveal that protective film is formed on the metal surface. Cyclic voltammetry study reveals that the protective film is more compact and stable even in a 3.5% NaCl environment. The nature of the protective film on a metal surface has been analyzed by FTIR, SEM, and AFM analysis.


2021 ◽  
Vol 62 (4) ◽  
pp. 277-290
Author(s):  
Josephath Praveena ◽  
Jeyaraj Clara ◽  
Susai Rajendran ◽  
Antony Amalraj

Inhibition efficiency of an aqueous extract of soapnut (Sapindus Trifoliatus) and Zn2+in controlling corrosion of mild steel in well water at room temperature has been evaluated by using weight loss method, polarization study and AC impedance spectra. Dynamic light scattering and Vickers hardness have also been employed. Weight loss method reveals that the formulation consisting of 10 ml soapnut extract and 50 ppm Zn2+ has 97 % inhibition efficiency in controlling corrosion of mild steel immersed in well water. Synergism parameters suggest that a synergistic effect exists between soapnut extract and Zn2+. Adsorption isotherm of metal surface obeys Langmuir adsorption isotherm. Polarization study reveals that the inhibitor system functions as anodic type of inhibitor. AC impedance spectra confirm the protective film formed on the metal surface. Dynamic light scattering (DLS) study reveals surface is in nano meter scale. The Vickers hardness of metal surface was increases in inhibitor system.


2021 ◽  
Vol 12 (2) ◽  
pp. 2603-2617

Corrosion inhibitive and adsorption capabilities of Tribulus terrestris plant extract on aluminum in 1.0 N HCl solution was evaluated by mass loss and electrochemical methods. The inhibition efficiency increased with increasing extract concentration, whereas it decreased with increasing immersion time. The adsorption of the extract on the metal surface was physisorption, supported by ΔGads values( around -20 kJ mol−1) and obeyed by Langmuir, Temkin and Freundlich adsorption isotherms. Electrochemical studies revealed mechanistic aspects of corrosion inhibition like Potentiodynamic polarization measurements indicated the nature of inhibitor is a mixed type and impedance studies supported the formation of a protective layer of inhibitor on a metal surface. SEM micrograms were also applied to study surface morphology. These images confirmed the creation of a protective film over the metal surface.


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