Adsorption and kinetic studies of piperidin-1-yl-ph osphonic acid as a corrosion inhibitor of iron in sulphuric acid mediu m (original) (raw)
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Investigation of the effect of piperidin-1-yl-phosphonic acid on corrosion of iron in sulfuric acid
Arabian Journal of Chemistry, 2016
The inhibitive effect of the piperidin-1-yl-phosphonic acid (PPA) on the corrosion of iron in 1 M H 2 SO 4 solution has been investigated by weight loss measurement, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The presence of (PPA) reduces remarkably the corrosion rate of iron in acidic solution. The effect of temperature on the corrosion behavior of iron was studied in the range of 298-328 K. Results clearly reveal that the (PPA) behaves as a mixed type corrosion inhibitor with the highest inhibition at 5 • 10 À3 M. The adsorption of PPA on the iron surface obeys the Langmuir's adsorption isotherm.
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The inhibition effect of N,N′-phosphonomethylglycine (PMG) and vinyl phosphonic acid (VPA) on the 3% NaCl acidic solution corrosion of carbon steel iron was studied at different immersion times by potentiodynamic polarization, electrochemical impedance spectroscopy, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, and computational methods. It is found from the polarization studies that PMG and VPA behave as mixed-type inhibitors in NaCl. Values of charge transfer resistance (Rct) and double layer capacitance (Cdl) in the absence and presence of inhibitors are determined. The PMG and VPA inhibitors were capable of inhibiting the corrosion process up to ≈91% and ≈85%, respectively. In the presence of PMG, the synergic effect of chlorine ions was observed. Density functional theory (DFT) was engaged to establish the adsorption site of PMG, VPA, and their deprotonated states. For studied compounds, the resulted values of ELUMO, EHOMO, energy gap (∆E), di...
Corrosion Science, 2008
Electrochemical techniques, weight loss method and surface analysis were used to study the synergistic inhibition offered by Zn 2+ and piperidin-1-yl-phosphonic acid (PPA) to the corrosion of Armco iron in 3% chloride solution. It is observed that the combination between PPA and Zn 2+ shows excellent inhibition efficiency. The potentiodynamic polarization curves reveal that 5 Â 10 À3 mol l À1 of PPA has only 76.7% inhibition efficiency whereas the mixture containing 5 Â 10 À3 mol l À1 PPA-20%Zn 2+ has 90.2% inhibition efficiency. This suggests that a synergistic effect exists between Zn 2+ and PPA. The Fourier transform infrared (FTIR) spectrum of the film formed on iron indicates phosphonates zinc salt formation. A suitable mechanism of corrosion inhibition is proposed based on the results obtained. The surface film analysis showed that in the absence of Zn 2+ , the protective film consists of Fe 2+-PPA complex formed on the anodic sites of the metal surface, whereas in the presence of Zn 2+ , the protective film consists of Fe 2+-PPA complex and Zn(OH) 2 .
2015
The inhibiting action of thiomorpholin-4-ylmethyl-phosphonic acid (TMPA) was investigated as the corrosion inhibitor of iron in 0.5M sulphuric acid (H 2 SO 4 ) solution with the aid of potentiodynamic polarization test, electrochemical impedance spectroscopy (EIS) and weight loss measurements. The results revealed that thiomorpholin-4-ylmethyl-phosphonic acid (TMPA) is a good, mixed type inhibitor. The inhibition efficiency of TMPA on iron corrosion increases with increase in concentration of (H 2 SO 4 ) and decreases with increase in temperature. The adsorption isotherm model of TMPA on the iron surface was in conformity with Langmuir isotherm model. Thermodynamic parameters were calculated and discussed. The local reactivity, analyzed by using Parr functions, shows that both sulphur and nitrogen atoms of TMPA are the main adsorption sites.
Inhibition of iron corrosion in 0.5M sulphuric acid by metal cations
Applied Surface Science, 2006
Corrosion inhibitors are widely used in acid solutions during pickling and descaling. Mostly organic compounds containing N, O, and S groups are employed as inhibitors. In this study, the inhibition performance of metal cations such as Zn 2+ , Mn 2+ and Ce 4+ ions in the concentration range 1-10 Â 10 À3 M has been found out. The corrosion behaviour of iron in 0.5 M H 2 SO 4 in the presence of metal cations is studied using polarization and impedance methods. It is found that the addition of these metal cations inhibits the corrosion markedly. The inhibition effect is in the following order Ce 4+) Mn 2+ > Zn 2+ .
Der Pharmacia Lettre, 2016
The corrosion inhibition efficiency of Sulfapyridine(SFP) for carbon steel in 2.0 M H 3 PO 4 has been studied using weight loss, polarization, electrochemical and impedance spectroscopy techniques. The results show that SFP is a good inhibitor in 2.0 M H 3 PO 4. Effects of temperature and acid concentration on inhibitive performance were investigated. Polarization curves reveal that SFP acts as a mixed-type inhibitor. The electrochemical impedance spectroscopy showed that the charge transfer resistance increases and the double layer capacitance decreases on increasing Sulfapyridine concentration. Activation energy of corrosion and other thermodynamic parameters such as standard free energy, standard enthalpy, and standard entropy of the adsorption process revealed better and well-ordered physical adsorption mechanism in the presence of Sulfapyridine. Adsorption isotherms in absence or presence of SFP as inhibitor appropriately fit the Langmuir isotherm. Theoretical investigations have established that the interaction of SFP with the metal steel surface is mainly through the Nitrogen, oxygen atoms, sulphonyl group and the π system of the aromatic ring.
Inhibitive effect of some phosphonate derivatives on the corrosion of carbon steel in 2 M H3PO4
2016
Corrosion inhibition performance of some phosphonate derivatives, namely, dodecylphosphonic acid (YM1), sodium methyl dodecylphosphonate (YM2) and methyl hydrogen dodecylphosphonate (YM3) on carbon steel in 2 M H3PO4 solution was investigated by means of weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. These compounds inhibit the corrosion rate even at very low concentrations and the order of increasing inhibition efficiency was correlated with the modification of the molecular structure of the inhibitors. Polarization curves indicated that these compounds acted primarily as mixed-type inhibitors. The adsorption of these compounds on carbon steel surface has been found to obey Langmuir's adsorption isotherm. E% values obtained from weight-loss and electrochemical methods were in good agreement. size:12.0pt;line-height:200%;font-family:"Times New Roman","serif"; color:black'>.
International Journal of Science and Technoledge , 2017
The corrosion inhibition potentials of alkaloid, saponin and flavonoid extracts of Ocimunbasilicumleaves were investigated by evaluating the corrosion behaviour of Iron immersed in 1.0 M H2SO4 solutions containing varied concentration of the extract (0.5 g/L, 1.0 g/L, 2.0 g/L, 3.5 g/L, 5.0 g/L, 7.5 g/L and 10.0 g/L) using chemical methods. Maximum temperature attained, reaction time, thermodynamic data and adsorption characterizations were utilized to evaluate the corrosion inhibition and adsorption properties of the extract. The results revealed that, the corrosion of Iron decreases with increase in concentration of alkaloid extract, saponin extract and flavonoid extract, also, increases with increase in H2SO4 concentration. The increase in addition of the green inhibitors to the corrosive medium, improve the values of inhibition efficiency of the extract in the order AEOBL > SEOBL > FEOBL. In all cases, Flavonoid extracts exhibits least effect on the corrosion of Zinc in comparison with alkaloids and saponins. Results obtained from adsorption studies indicated that, all the green inhibitors were adsorbed on the surface of the Iron and that the adsorption fit excellently with the assumptions of the Langmuir adsorption isotherm model. All data acquired revealed that Ocimunbasilicum leaves are efficient inhibitors of corrosion in acid medium due to the presence of heterocompounds: saponins, tannins, flavonoids, glycosides, carbohydrates, reducing sugars, terpenoids, steroids and alkaloids.
2015
In the first part of this study, the effect of addition of various cations (Cu 2+ , Mn 2+ , Ca 2+ , Zn 2+ ) and the aminotris(methylenephosphonic) acid (ATMP) on the inhibition of iron corrosion in 1M HCl were studied using electrochemical methods (polarisation curves and EIS). Results indicate a significant synergistic effect between ATMP and Zn +2 . In the second part, the corrosion behaviour of iron in 1M HCl in the absence and presence of different ratios Zn/ATMP was studied using weight loss test and electrochemical techniques. The immersion solutions were analyzed using the spectroscopy induction coupled plasma. The results confirm the presence of synergistic effect between ATMP and Zn 2+ , which can be was attributed to the formation of Zn and ATMP complex. The maximum protection efficiency was observed at the ratio Zn/ATMP: 50%/50%.