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The Effect of Magnetic Field on Corrosion Inhibitor of Copper in 0.5 M HCl Solution
Available online at www.sciencedirect.com
ScienceDirect Procedia Chemistry 19 (2016) 222 – 227
5th International Conference on Recent Advances in Materials, Minerals and Environment (RAMM) & 2nd International Postgraduate Conference on Materials, Mineral and Polymer (MAMIP), 4-6 August 2015
The Effect of Magnetic Field on Corrosion Inhibitor of Copper in 0.5 M HCl Solution L. Y. Anga, N. K. Othmana*, A. Jalarb, I. Ismailc a
School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia Institute of Microengineering and nanoelectronics (IMEN), Level 4, Research Complex, Universiti Kebangsaan Malaysia, Malaysia b Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia. b
Abstract Corrosion of metals within magnetic field (MF) had been actively studied for better understanding of the corrosion mechanism when the magnetic sources are presented. However, findings regarding the effect of MF on metals are inconclusive, and there is a lack of studies of MF interaction with various corrosion control techniques, such as corrosion inhibitor. In this paper, the effect of MF on the corrosion of copper in 0.5 M hydrochloric acid (HCl) solution, with or without corrosion inhibitor were studied. Benzotriazole (BTA), a common copper inhibitor, was chosen as the inhibitor for this study. To determine the effect of MF, a MF of 13 mT, generated using a pair of permanent neodymium magnet, was applied during weight loss and electrochemical tests. The results showed that corrosion inhibition efficiency of BTA decreased when it is under an applied MF. A decrease from 47% to 60% in inhibition efficiency had been observed for all samples in an applied MF. By using Tafel extrapolation technique on the polarization curves, it revealed that MF had increased the corrosion current of copper in HCl, causing a decrease in the inhibition efficiency. © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license
© 2016 The Authors. Published by Elsevier B.V. (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia. Peer-review under responsibility of School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia
Keywords: corrosion;copper;magnetic field;benzotriazole;electrochemical
* Corresponding author. Tel.: +603-8921-5907. E-mail address: [email protected]
1876-6196 © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia doi:10.1016/j.proche.2016.03.097
223
L.Y. Ang et al. / Procedia Chemistry 19 (2016) 222 – 227
1. Introduction The exact mechanism that governs the corrosion of metals within an applied magnetic field is very complex and it is still unclear how magnetic field interacts with the chemical reaction. Magnetic field may increases or decreases corrosion rate depends, the metals, solution and the properties of the magnetic field. Thus corrosion under magnetic field had been actively studied, as better understanding of the governing mechanism will help in developing suitable corrosion prevention strategy when the magnetic sources are presented. Several studies had determined that magnetic field can affect the mass transfer via Lorentz force1. This force, FL, can be described in Eq. 1 as
FL
q(E v u B)
(1)
where q is the electron charge, E is the electrical field, v is velocity vector of the electron and B is the applied magnetic field strength. Magnetic field gradient force is also shown to be significant for cases like corrosion of iron in H2SO4 2. This gradient force, FB, can be described in Eq. 2 as
FB
Fmc
BB
P0
(2)
where χm is the molar susceptibility, c is the concentration of bulk solution and μ 0 is the magnetic permeability of vacuum. The effect on the charge transfer is more controversial. Although it had been demonstrated that it had no effect of magnetic field on several pure redox systems3,4, it is not clear if this case was true for all processes, such as in the case of stainless steel corrosion in FeCl3 solution 5. Corrosion of copper in chloride medium is dependent of the concentration of the chloride ions. Anodic dissolution of copper into soluble CuCl2 occurred when copper reacts with excess chloride ions, and that process is controlled by both mass transport and charge transfer 6. Several studies had been done on corrosion of copper in chloride medium with applied magnetic field 7,8, and found that magnetic field increases the corrosion rate of copper. Mass transfer had been significantly enhanced during corrosion of copper under an applied magnetic field, which induces magnetohydradynamic (MHD) flows that can be observed using holography method 9. Benzotriazole (BTA) is a heterocyclic organic compound, with chemical formula of C 6H5N3, and molecular structure as shown in Fig. 1, is commonly used as corrosion inhibitor of copper in acidic or neutral medium. It protects the surface of copper by bonding with nitrogen atoms on the triazole ring. The inhibition mechanism is complex, but chemisorption, rearly physisorption and formation of complex Cu(I)BTA had been identified as the possible actions involved 10,11. However, there is little research done on the effect of magnetic field on the corrosion inhibitor of metals, and if this strategy is viable when magnetic sources are nearby. The interaction between the induced MHD flows with the adsorption mechanism of benzotriazole is therefore worth exploring further. In this study, the effect of magnetic field on corrosion efficiency of BTA when it is applied on copper in 0.5 M HCl were studied. The effect was observed via weight loss test and electrochemical test, where a pair of neodymium permanent magnet is used to generate an applied magnetic field normal to the surface of the copper. Nomenclature MF BTA MHD IE
magnetic field benzotriazole magnetohydradynamic inhibition efficiency
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L.Y. Ang et al. / Procedia Chemistry 19 (2016) 222 – 227
Fig. 1. Molecular structure of BTA.
2. Methodology In this study, copper of 99% purity had been used throughout the experiment. 0.5 M HCl and various concentration of BTA (100 ppm, 200 ppm and 300 ppm) were prepared using reagent grade chemicals. Magnetic field was generated using a pair of neodymium permanent magnet, where it was setup as was shown in Fig. 2. Magnetic field strength of 13 mT had been used throughout this study, and the magnetic field strength is verified using a Hall-effect probe connected to a teslameter (Linkjoint LZ-610H). For weight loss test, copper coupons of diameter 16.5 cm and thickness of 0.35 cm were ground using silicon carbide abrasive using grit size up to #800, and then cleaned using distilled water and acetone. The coupons were then immersed in test solutions for 24 hours before it is weighed using electric weight. For electrochemical test, Gamry PC4/750 with DC105 DC Corrosion Techniques Software suite were used as the potentiostat. Saturated calomel electrode were used as the reference electrode, and carbon as counter electrode. Luggin capillary were placed close to copper surface to reduce the ohmic resistance. Voltage range of ±250 mV from open circuit potential is used during polarization, with the scan rate of 1 mV/s. The setup were left for 30 min before running the test to stabilize the open circuit potential. The spectra obtained were then analyzed using Tafel extrapolation technique.
Fig. 2. Schematics of experimental setup used throughout this study. B is magnetic vector field.
3. Results and Discussion Weight loss test results were shown in Fig. 3 and Table 1. The corrosion inhibition efficiency of BTA based on the weight loss test results were calculated using Eq. 3.
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L.Y. Ang et al. / Procedia Chemistry 19 (2016) 222 – 227
IE
CR f CR0 CR0
u 100 %
(3)
where IE is inhibition efficiency, CR0 is the untreated corrosion rate, and CRf is the corrosion rate under applied magnetic field. The results showed that corrosion inhibition efficiency of BTA decreased when it is under an applied magnetic field. A decrease from 47% to 60% in inhibition efficiency had been observed for all samples in an applied magnetic field. None of BTA had successfully protected the copper from corrosion, which suggested that magnetic field had affected the protective mechanism of BTA. However, corrosion rate did decreases with increasing concentration of BTA, even under the influence of magnetic field, which suggests that effect of BTA is not totally nullified by the magnetic field. The rate of decrease is slightly decrease for BTA when under magnetic field; assuming linear regression, corrosion rate without magnetic field decreases at a rate of 8.22 × 10 -4 (mm year-1)/ppm with R2 of 0.9324, but with magnetic field the rate of decrease is 7.44 × 10 -4 (mm year-1)/ppm with R2 of 0.9994. Electrochemical test results were shown in Fig. 4 and Table 2. Using data from Tafel extrapolation, the corrosion inhibition efficiency of BTA based on the Tafel extrapolation were calculated using Eq. 4.
IE
i 0corr i f corr u 100 % i 0corr
(4)
Corrosion rate (mm/year)
where IE is inhibition efficiency, i0corr is the untreated corrosion current density, and ifcorr is the corrosion rate under applied magnetic field. It can be seen that corrosion current density had increased when copper is under an applied magnetic field. This suggested that an incomplete protective film may had been formed on the surface of the copper, which may affected by turbulence induced by MHD effect during the mass transport controlled part of copper corrosion. The increases of anodic slope, B a, also suggested that adsorption of copper may had been disrupted by the magnetic field. However, lack of significant changes in the corrosion potential, E corr, suggested that no significant change had occurred to the charge transfer step of copper dissolution, which is consistent with the previous findings. There seems there is little linear correlation between concentration of BTA and i corr, however, when it is compared to mass lost test. This is more pronounced in the case of 300 ppm BTA in applied magnetic field, where i corr is significantly higher than expected. This may suggests that most of corrosion occurred during the first hour, and adsorption of BTA occurred at much lower rate that allows more copper dissolution before a complete film had been formed.
0.6 0.5
No MF With MF
0.4 0.3 0.2 0.1
0 100 200 300 BTA concentration (ppm) Fig. 3. Result of the weight loss test, with and without applied MF.
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L.Y. Ang et al. / Procedia Chemistry 19 (2016) 222 – 227 Table 1. Weight loss test result. CR/mm year-1 0.3498 0.3766 0.5690 0.3327 0.4978 0.2121 0.4201
Solutions 0.5M HCl 0.5M HCl + 100 ppm IMD (no MF) 0.5M HCl + 100 ppm IMD (with MF) 0.5M HCl + 200 ppm IMD (no MF) 0.5M HCl + 200 ppm IMD (with MF) 0.5M HCl + 300 ppm IMD (no MF) 0.5M HCl + 300 ppm IMD (with MF)
IE/% -7.66 -62.66 4.88 -42.31 39.37 -20.10
Fig. 4. Polarization curve of copper in 0.5M HCl and BTA, with and without applied MF. Table 2. Electrochemical test result. Solutions
Ecorr/mV
icorr/µA cm-2
0.5M HCl 0.5M HCl + 100 ppm IMD (no MF) 0.5M HCl + 100 ppm IMD (with MF) 0.5M HCl + 200 ppm IMD (no MF) 0.5M HCl + 200 ppm IMD (with MF) 0.5M HCl + 300 ppm IMD (no MF) 0.5M HCl + 300 ppm IMD (with MF)
-180.7 -216.9 -207.5 -214.8 -217.0 -210.5 -202.6
4.140 3.106 6.911 3.506 4.164 3.456 9.252
Βc/mV Decade-1 282.6 217.4 257.0 215.3 214.6 193.2 316.9
Βa/mV Decade-1 39.8 40.4 47.9 44.6 49.6 41.0 49.8
Rp/kΩ cm2 3.661 4.762 2.536 4.574 4.205 4.249 2.020
IE/% 24.98 -66.93 15.31 -0.58 16.52 -123.48
L.Y. Ang et al. / Procedia Chemistry 19 (2016) 222 – 227
4. Conclusion In general, from weight loss test and electrochemical analysis, inhibition efficiency of BTA in 0.5 M HCl had decreased when it is under an applied magnetic field in this investigation. There is no change of charge transfer mechanism has been observed via tafel extrapolation due to insignificant variant of E corr values. This phenomena can be explained by considering the induced MHD effect that retards or disrupt the adsorption mechanism of BTA on the copper interface. Therefore, protective film may not be properly formed to protect the copper from corrosion. Acknowledgements We would like to thanks Ministry of Education Malaysia for financial support via MyBrain15 scholarship program. This work was partially supported by ERGS/1/2012/ST205/UKM/02/2 and FRGS/2/2013/SG06/ UKM/02/4 grant. References 1.
Sueptitz R, Tschulik K, Uhlemann M, Schultz L, Gebert A. Magnetic field effects on the active dissolution of iron. Electrochim Acta 2011;56:5866–71. doi:10.1016/j.electacta.2011.04.126. 2. Sueptitz R, Tschulik K, Uhlemann M, Gebert a., Schultz L. Impact of magnetic field gradients on the free corrosion of iron. Electrochim Acta 2010;55:5200–3. doi:10.1016/j.electacta.2010.04.039. 3. Devos O, Aaboubi O, Chopart J, Olivier A, Gabrielli C, Tribollet B. Is There a Magnetic Field Effect on Electrochemical Kinetics? J Phys Chem A 2000;104:1544–8. doi:10.1021/jp993696v. 4. Koehler S, Bund A. Investigations on the kinetics of electron transfer reactions in magnetic fields. J Phys Chem B 2006;110:1485–9. doi:10.1021/jp0550964. 5. Ručinskienė A, Bikulčius G, Gudavičiūtė L, Juzeliūnas E. Magnetic field effect on stainless steel corrosion in FeCl3 solution. Electrochem Commun 2002;4:86–91. doi:10.1016/S1388-2481(01)00280-6. 6. Kear G, Barker BD, Walsh FC. Electrochemical corrosion of unalloyed copper in chloride media––a critical review. Corros Sci 2004;46:109–35. doi:10.1016/S0010-938X(02)00257-3. 7. GUO B, ZHANG P, JIN Y, CHENG S. Effects of alternating magnetic field on the corrosion rate and corrosion products of copper. Rare Met 2008;27:324–8. doi:10.1016/S1001-0521(08)60138-2. 8. Hu J, Dong C, Li X, Xiao K. Effects of Applied Magnetic Field on Corrosion of Beryllium Copper in NaCl Solution. J Mater Sci Technol 2010;26:355–61. doi:10.1016/S1005-0302(10)60058-8. 9. Yuan B, Wang C, Li L, Chen S. Investigation of the effects of the magnetic field on the anodic dissolution of copper in NaCl solutions with holography. Corros Sci 2012;58:69–78. doi:10.1016/j.corsci.2012.01.005. 10. Antonijevic MM, Petrovic MB. Copper Corrosion Inhibitors . A review. Int J Electrochem Sci 2008;3:1–28. doi:10.1016/j.ijengsci.2004.12.001. 11. Antonijević MM, Milić SM, Petrović MB. Films formed on copper surface in chloride media in the presence of azoles. Corros Sci 2009;51:1228–37. doi:10.1016/j.corsci.2009.03.026.
227
ScienceDirect Procedia Chemistry 19 (2016) 222 – 227
5th International Conference on Recent Advances in Materials, Minerals and Environment (RAMM) & 2nd International Postgraduate Conference on Materials, Mineral and Polymer (MAMIP), 4-6 August 2015
The Effect of Magnetic Field on Corrosion Inhibitor of Copper in 0.5 M HCl Solution L. Y. Anga, N. K. Othmana*, A. Jalarb, I. Ismailc a
School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia Institute of Microengineering and nanoelectronics (IMEN), Level 4, Research Complex, Universiti Kebangsaan Malaysia, Malaysia b Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia. b
Abstract Corrosion of metals within magnetic field (MF) had been actively studied for better understanding of the corrosion mechanism when the magnetic sources are presented. However, findings regarding the effect of MF on metals are inconclusive, and there is a lack of studies of MF interaction with various corrosion control techniques, such as corrosion inhibitor. In this paper, the effect of MF on the corrosion of copper in 0.5 M hydrochloric acid (HCl) solution, with or without corrosion inhibitor were studied. Benzotriazole (BTA), a common copper inhibitor, was chosen as the inhibitor for this study. To determine the effect of MF, a MF of 13 mT, generated using a pair of permanent neodymium magnet, was applied during weight loss and electrochemical tests. The results showed that corrosion inhibition efficiency of BTA decreased when it is under an applied MF. A decrease from 47% to 60% in inhibition efficiency had been observed for all samples in an applied MF. By using Tafel extrapolation technique on the polarization curves, it revealed that MF had increased the corrosion current of copper in HCl, causing a decrease in the inhibition efficiency. © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license
© 2016 The Authors. Published by Elsevier B.V. (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia. Peer-review under responsibility of School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia
Keywords: corrosion;copper;magnetic field;benzotriazole;electrochemical
* Corresponding author. Tel.: +603-8921-5907. E-mail address: [email protected]
1876-6196 © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia doi:10.1016/j.proche.2016.03.097
223
L.Y. Ang et al. / Procedia Chemistry 19 (2016) 222 – 227
1. Introduction The exact mechanism that governs the corrosion of metals within an applied magnetic field is very complex and it is still unclear how magnetic field interacts with the chemical reaction. Magnetic field may increases or decreases corrosion rate depends, the metals, solution and the properties of the magnetic field. Thus corrosion under magnetic field had been actively studied, as better understanding of the governing mechanism will help in developing suitable corrosion prevention strategy when the magnetic sources are presented. Several studies had determined that magnetic field can affect the mass transfer via Lorentz force1. This force, FL, can be described in Eq. 1 as
FL
q(E v u B)
(1)
where q is the electron charge, E is the electrical field, v is velocity vector of the electron and B is the applied magnetic field strength. Magnetic field gradient force is also shown to be significant for cases like corrosion of iron in H2SO4 2. This gradient force, FB, can be described in Eq. 2 as
FB
Fmc
BB
P0
(2)
where χm is the molar susceptibility, c is the concentration of bulk solution and μ 0 is the magnetic permeability of vacuum. The effect on the charge transfer is more controversial. Although it had been demonstrated that it had no effect of magnetic field on several pure redox systems3,4, it is not clear if this case was true for all processes, such as in the case of stainless steel corrosion in FeCl3 solution 5. Corrosion of copper in chloride medium is dependent of the concentration of the chloride ions. Anodic dissolution of copper into soluble CuCl2 occurred when copper reacts with excess chloride ions, and that process is controlled by both mass transport and charge transfer 6. Several studies had been done on corrosion of copper in chloride medium with applied magnetic field 7,8, and found that magnetic field increases the corrosion rate of copper. Mass transfer had been significantly enhanced during corrosion of copper under an applied magnetic field, which induces magnetohydradynamic (MHD) flows that can be observed using holography method 9. Benzotriazole (BTA) is a heterocyclic organic compound, with chemical formula of C 6H5N3, and molecular structure as shown in Fig. 1, is commonly used as corrosion inhibitor of copper in acidic or neutral medium. It protects the surface of copper by bonding with nitrogen atoms on the triazole ring. The inhibition mechanism is complex, but chemisorption, rearly physisorption and formation of complex Cu(I)BTA had been identified as the possible actions involved 10,11. However, there is little research done on the effect of magnetic field on the corrosion inhibitor of metals, and if this strategy is viable when magnetic sources are nearby. The interaction between the induced MHD flows with the adsorption mechanism of benzotriazole is therefore worth exploring further. In this study, the effect of magnetic field on corrosion efficiency of BTA when it is applied on copper in 0.5 M HCl were studied. The effect was observed via weight loss test and electrochemical test, where a pair of neodymium permanent magnet is used to generate an applied magnetic field normal to the surface of the copper. Nomenclature MF BTA MHD IE
magnetic field benzotriazole magnetohydradynamic inhibition efficiency
224
L.Y. Ang et al. / Procedia Chemistry 19 (2016) 222 – 227
Fig. 1. Molecular structure of BTA.
2. Methodology In this study, copper of 99% purity had been used throughout the experiment. 0.5 M HCl and various concentration of BTA (100 ppm, 200 ppm and 300 ppm) were prepared using reagent grade chemicals. Magnetic field was generated using a pair of neodymium permanent magnet, where it was setup as was shown in Fig. 2. Magnetic field strength of 13 mT had been used throughout this study, and the magnetic field strength is verified using a Hall-effect probe connected to a teslameter (Linkjoint LZ-610H). For weight loss test, copper coupons of diameter 16.5 cm and thickness of 0.35 cm were ground using silicon carbide abrasive using grit size up to #800, and then cleaned using distilled water and acetone. The coupons were then immersed in test solutions for 24 hours before it is weighed using electric weight. For electrochemical test, Gamry PC4/750 with DC105 DC Corrosion Techniques Software suite were used as the potentiostat. Saturated calomel electrode were used as the reference electrode, and carbon as counter electrode. Luggin capillary were placed close to copper surface to reduce the ohmic resistance. Voltage range of ±250 mV from open circuit potential is used during polarization, with the scan rate of 1 mV/s. The setup were left for 30 min before running the test to stabilize the open circuit potential. The spectra obtained were then analyzed using Tafel extrapolation technique.
Fig. 2. Schematics of experimental setup used throughout this study. B is magnetic vector field.
3. Results and Discussion Weight loss test results were shown in Fig. 3 and Table 1. The corrosion inhibition efficiency of BTA based on the weight loss test results were calculated using Eq. 3.
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L.Y. Ang et al. / Procedia Chemistry 19 (2016) 222 – 227
IE
CR f CR0 CR0
u 100 %
(3)
where IE is inhibition efficiency, CR0 is the untreated corrosion rate, and CRf is the corrosion rate under applied magnetic field. The results showed that corrosion inhibition efficiency of BTA decreased when it is under an applied magnetic field. A decrease from 47% to 60% in inhibition efficiency had been observed for all samples in an applied magnetic field. None of BTA had successfully protected the copper from corrosion, which suggested that magnetic field had affected the protective mechanism of BTA. However, corrosion rate did decreases with increasing concentration of BTA, even under the influence of magnetic field, which suggests that effect of BTA is not totally nullified by the magnetic field. The rate of decrease is slightly decrease for BTA when under magnetic field; assuming linear regression, corrosion rate without magnetic field decreases at a rate of 8.22 × 10 -4 (mm year-1)/ppm with R2 of 0.9324, but with magnetic field the rate of decrease is 7.44 × 10 -4 (mm year-1)/ppm with R2 of 0.9994. Electrochemical test results were shown in Fig. 4 and Table 2. Using data from Tafel extrapolation, the corrosion inhibition efficiency of BTA based on the Tafel extrapolation were calculated using Eq. 4.
IE
i 0corr i f corr u 100 % i 0corr
(4)
Corrosion rate (mm/year)
where IE is inhibition efficiency, i0corr is the untreated corrosion current density, and ifcorr is the corrosion rate under applied magnetic field. It can be seen that corrosion current density had increased when copper is under an applied magnetic field. This suggested that an incomplete protective film may had been formed on the surface of the copper, which may affected by turbulence induced by MHD effect during the mass transport controlled part of copper corrosion. The increases of anodic slope, B a, also suggested that adsorption of copper may had been disrupted by the magnetic field. However, lack of significant changes in the corrosion potential, E corr, suggested that no significant change had occurred to the charge transfer step of copper dissolution, which is consistent with the previous findings. There seems there is little linear correlation between concentration of BTA and i corr, however, when it is compared to mass lost test. This is more pronounced in the case of 300 ppm BTA in applied magnetic field, where i corr is significantly higher than expected. This may suggests that most of corrosion occurred during the first hour, and adsorption of BTA occurred at much lower rate that allows more copper dissolution before a complete film had been formed.
0.6 0.5
No MF With MF
0.4 0.3 0.2 0.1
0 100 200 300 BTA concentration (ppm) Fig. 3. Result of the weight loss test, with and without applied MF.
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L.Y. Ang et al. / Procedia Chemistry 19 (2016) 222 – 227 Table 1. Weight loss test result. CR/mm year-1 0.3498 0.3766 0.5690 0.3327 0.4978 0.2121 0.4201
Solutions 0.5M HCl 0.5M HCl + 100 ppm IMD (no MF) 0.5M HCl + 100 ppm IMD (with MF) 0.5M HCl + 200 ppm IMD (no MF) 0.5M HCl + 200 ppm IMD (with MF) 0.5M HCl + 300 ppm IMD (no MF) 0.5M HCl + 300 ppm IMD (with MF)
IE/% -7.66 -62.66 4.88 -42.31 39.37 -20.10
Fig. 4. Polarization curve of copper in 0.5M HCl and BTA, with and without applied MF. Table 2. Electrochemical test result. Solutions
Ecorr/mV
icorr/µA cm-2
0.5M HCl 0.5M HCl + 100 ppm IMD (no MF) 0.5M HCl + 100 ppm IMD (with MF) 0.5M HCl + 200 ppm IMD (no MF) 0.5M HCl + 200 ppm IMD (with MF) 0.5M HCl + 300 ppm IMD (no MF) 0.5M HCl + 300 ppm IMD (with MF)
-180.7 -216.9 -207.5 -214.8 -217.0 -210.5 -202.6
4.140 3.106 6.911 3.506 4.164 3.456 9.252
Βc/mV Decade-1 282.6 217.4 257.0 215.3 214.6 193.2 316.9
Βa/mV Decade-1 39.8 40.4 47.9 44.6 49.6 41.0 49.8
Rp/kΩ cm2 3.661 4.762 2.536 4.574 4.205 4.249 2.020
IE/% 24.98 -66.93 15.31 -0.58 16.52 -123.48
L.Y. Ang et al. / Procedia Chemistry 19 (2016) 222 – 227
4. Conclusion In general, from weight loss test and electrochemical analysis, inhibition efficiency of BTA in 0.5 M HCl had decreased when it is under an applied magnetic field in this investigation. There is no change of charge transfer mechanism has been observed via tafel extrapolation due to insignificant variant of E corr values. This phenomena can be explained by considering the induced MHD effect that retards or disrupt the adsorption mechanism of BTA on the copper interface. Therefore, protective film may not be properly formed to protect the copper from corrosion. Acknowledgements We would like to thanks Ministry of Education Malaysia for financial support via MyBrain15 scholarship program. This work was partially supported by ERGS/1/2012/ST205/UKM/02/2 and FRGS/2/2013/SG06/ UKM/02/4 grant. References 1.
Sueptitz R, Tschulik K, Uhlemann M, Schultz L, Gebert A. Magnetic field effects on the active dissolution of iron. Electrochim Acta 2011;56:5866–71. doi:10.1016/j.electacta.2011.04.126. 2. Sueptitz R, Tschulik K, Uhlemann M, Gebert a., Schultz L. Impact of magnetic field gradients on the free corrosion of iron. Electrochim Acta 2010;55:5200–3. doi:10.1016/j.electacta.2010.04.039. 3. Devos O, Aaboubi O, Chopart J, Olivier A, Gabrielli C, Tribollet B. Is There a Magnetic Field Effect on Electrochemical Kinetics? J Phys Chem A 2000;104:1544–8. doi:10.1021/jp993696v. 4. Koehler S, Bund A. Investigations on the kinetics of electron transfer reactions in magnetic fields. J Phys Chem B 2006;110:1485–9. doi:10.1021/jp0550964. 5. Ručinskienė A, Bikulčius G, Gudavičiūtė L, Juzeliūnas E. Magnetic field effect on stainless steel corrosion in FeCl3 solution. Electrochem Commun 2002;4:86–91. doi:10.1016/S1388-2481(01)00280-6. 6. Kear G, Barker BD, Walsh FC. Electrochemical corrosion of unalloyed copper in chloride media––a critical review. Corros Sci 2004;46:109–35. doi:10.1016/S0010-938X(02)00257-3. 7. GUO B, ZHANG P, JIN Y, CHENG S. Effects of alternating magnetic field on the corrosion rate and corrosion products of copper. Rare Met 2008;27:324–8. doi:10.1016/S1001-0521(08)60138-2. 8. Hu J, Dong C, Li X, Xiao K. Effects of Applied Magnetic Field on Corrosion of Beryllium Copper in NaCl Solution. J Mater Sci Technol 2010;26:355–61. doi:10.1016/S1005-0302(10)60058-8. 9. Yuan B, Wang C, Li L, Chen S. Investigation of the effects of the magnetic field on the anodic dissolution of copper in NaCl solutions with holography. Corros Sci 2012;58:69–78. doi:10.1016/j.corsci.2012.01.005. 10. Antonijevic MM, Petrovic MB. Copper Corrosion Inhibitors . A review. Int J Electrochem Sci 2008;3:1–28. doi:10.1016/j.ijengsci.2004.12.001. 11. Antonijević MM, Milić SM, Petrović MB. Films formed on copper surface in chloride media in the presence of azoles. Corros Sci 2009;51:1228–37. doi:10.1016/j.corsci.2009.03.026.
227