• Journal of the Korean Chemical Society
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• v.46 no.1
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• pp.19-25
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• 2002

We measured the variations of potentials and current densities for several polymers. The results were carefully examined to identify various factors such as temperature and pH to influence the potential and rate. The Tafel slope for anodic dissolution was determined by the polarization effect under these conditions. The optimum conditions were established for each case. The second anodic current density peak and maximum current density were designated as the relative polarization sensitivity $(I_r/I_f)$. The mass-transfer coefficient value $({\alpha})$ was determined by the Tafel slope for anodic dissolution on the basis of the polarization effect under optimum conditions.

• Proceedings of the KWS Conference
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• 2004.05a
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• pp.293-295
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• 2004

For the evaluation of corrosion resistance, Al 6061-T6 alloy was welded by Friction Sti. Welding(FSW) and Gas Metal Arc Welding(GMAW) evaluated by Tafel method and immersion test. The Tafel and immersion test results indicated that GMA weld was severely attacked compared with those of friction stir weld. It may be mainly due to the galvanic corrosion mechanism act on the CMA weld.

• Journal of the Korean Chemical Society
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• v.45 no.2
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• pp.138-160
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• 2001

In this study we measured oxidation potentials and current densities for poly(vinylcholride) (PVC) and poly(carbonate)(PC) in nonaqueous solutions, in order to find out how corrosion (oxidation) potentials depend on temperature, pH, enzyme, or added salts. The Tafel's slopes were determined from the Tafel plots of polarization curves. The transfer coefficients (${\alpha}$) wre evaluated from the slope(1-${\alpha}$)nF/2.3 RT, and the electrode reactions appeared irreversible under all conditions.

• Bulletin of the Korean Chemical Society
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• v.18 no.9
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• pp.972-976
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• 1997

Single phase ruthenium oxides with perovskite (ATi1-xRuxO3 (A=Ca, Sr)) and pyrochlore structure (Bi2Ru2O7, Pb2Ru2O6.5) have been prepared reproducibly by solid state reaction methods and their electrocatalytic activities for oxygen evolution have been examined by Tafel plots. Tafel slopes vary from a low value of 42 mV/decade up to 222 mV/decade at room temperature. The high exchange current densities and high Tafel slopes compared with those obtained from the RuO2 DSA electrode at the crystalline single phase metal oxide electrodes suggest that they are better electrocatalysts at low overpotentials. A favorable change in the Tafel slope for the oxygen evolution reaction occurs as the ruthenium content increases. Substitution of Ti for Ru in the perovskite solid solutions enhanced their chemical stability by losing marginal electrochemical activity.

• Journal of the Korean Chemical Society
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• v.51 no.1
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• pp.14-20
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• 2007

The anodic dissolution of electrodeposited iron group elements (Fe, Co, Ni) were studied in phthalate buffer solution. The pH dependence of the corrosion potential, the corrosion current and Tafel slope was measured for each element. Based on the electrochemical parameters including Tafel slopes, we proposed the redox mechanism of the corrosion and the passivation. The adsorption of various phthalate species on the electrodeposited iron group elements seemed to be affected the corrosion mechanisms.

• Journal of Electrochemical Science and Technology
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• v.13 no.4
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• pp.497-503
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• 2022

Spinel ferrites (Ni_xFe_3-xO₄; x = 0.25, 0.5, 0.75 and 1.0) have been prepared at 550℃ by egg white auto-combustion route using egg white at 550℃ and characterized by physicochemical (TGA, IR, XRD, and SEM) and electrochemical (CV and Tafel polarization) techniques. The presence of characteristic vibration peaks in FT-IR and reflection planes in XRD spectra confirmed the formation of spinel ferrites. The prepared oxides were transformed into oxide film on glassy carbon electrodes by coating oxide powder ink using the nafion solution and investigated their electrocatalytic performance for OER in an alkaline solution. The cyclic voltammograms of the oxide electrode did not show any redox peaks in oxygen overpotential regions. The iR-free Tafel polarization curves exhibited two Tafel slopes (b₁ = 59-90 mV decade^-1 and b₂ = 92-124 mV decade^-1) in lower and higher over potential regions, respectively. Ni-substitution in oxide matrix significantly improved the electrocatalytic activity for oxygen evolution reaction. Based on the current density for OER, the 0.75 mol Ni-substituted oxide electrode was found to be the most active electrode among the prepared oxides and showed the highest value of apparent current density (~9 mA cm^-2 at 0.85 V) and lowest Tafel slope (59 mV decade^-1). The OER on oxide electrodes occurred via the formation of chemisorbed intermediate on the active sites of the oxide electrode and follow the second-order mechanism.

• International Journal of Concrete Structures and Materials
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• v.4 no.2
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• pp.71-75
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• 2010

The chloride ion attack on the passive iron oxide layer of reinforcement steel embedded in concrete under variable temperature environment is influenced by several parameters and some of them still need to be further investigated in more detail. Different school of thoughts exist between past researchers and the data is limited in the high temperature and high chloride concentration range which is necessary with regards to setting boundary conditions for enhancement of tafel diagram model presented in this research. The objective of this paper is to investigate the detrimental coupled effects of chloride and temperature on corrosion of reinforced concrete structures in the high range by incorporating classical Tafel diagram chloride induced corrosion model and laboratory controlled experimental non-linear effect of temperature on corrosion of rebar embedded in concrete.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_1
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• pp.47-53
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• 2001

We carroed our to measure the variations of potential with current density (polarization curves) for poly(ethyleneterephthalate). The results were particularly examined to identify the influences on corrosion potential and corrosion rate of various factors including temperature, pH, exposure time, salt, and enzyme. The Tafel slope for anodic dissolution was determined by the polarization effect depending on these conditions. The optimum conditions were established for each case. The second anodic current density peak and maximum passive current density were designated as the relative corrosion sensitivity$(I_r/I_f)$. The mass transfer coefficient value$(\alpha)$ was determined with the Tafel slope for anodic dissolution based on the polarization effect with optimum conditions.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.3 no.3
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• pp.159-167
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• 1999

This study performed experiments for measuring corrosion potential and current density variations in the polarzation curves of polyvinylchloride. The results were examined to identify particular influences affectingthe corrosion potential such as temperature, pH, enzyme, and salt. The lines representing active anodic dissolution were only slightly shifted in the potential direction by temperature, pH, enzyme and salt. The Tafel slope for the anodic dissolution was determined using the polarization effect with varying conditions. The slope of the polarization curves describing the active-to-passive transition region was noticeably shifted in the potential direction. In addition, using the variation in conditions, the best temperature and pH were determined for the corrosion rate, and resistance of corrosion. The second anodic current density peak and maximum passive current density were designated as degraded(IP/I0). The value of IP/I0 was used in measuring the extent of the degradation of the polyvinychloride. The potentiodynamic parameters of the corrosion were obtained using a Tafel plot.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_4
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• pp.181-187
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• 2001

This study was carried out to measure the variations of potential and current density with polymers. The results were particularly examined to identify the influences on potential and rate of various factors including temperature and pH. The Tafel slope for anodic dissolution was determined by the polarization effect depending on these conditions. The optimum conditions were established for each case. The second anodic current density peak and maximum current density were designated as the relative polarization sensitivity$(I_r/I_f)$. The mass transfer coefficient value$(\alpha)$ was determined with the Tafel slope for anodic dissolution based on the polarization effect with optimum conditions.