• 대한화학회지
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• 제46권1호
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• pp.19-25
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• 2002

우리는 고분자 물질들에 대해서 전위와 전류 밀도의 변화를 측정하였다. 온도와 pH를 포함하여 전위와 속도에 대한 영향을 주는 여러 요인들에 밝히기 위하여, 연구 결과들이 주위 깊게 조사되었다. 양극 해리에 대한 Tafel 기울기는 이들 조건 하에서 분극 효과로 결정되었다. 각 경우에 최적 조건들이 확립되었다. 두 번째 양극 전류 밀도 피크와 최대 전류 밀도는 상대적 분극 감도$(I_r/I_f)$로 지정되었다. 최적 조건에서의 분극 효과를 바탕으로, 질량 전달 계수$({\alpha})$는 양극 해리에 대한 Tafel 기울기에 의해서 결정되었다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2004년도 춘계 학술발표대회 개요집
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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.

• 대한화학회지
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• 제45권2호
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• pp.138-160
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• 2001

이 연구에서 온도, pH, 효소, 그리고 염의 첨가에 따라 부식(산화)전위에 영향을 주 인자들을 알아보기위해 비수용액 poly(vinylchloride)(PVC)와 poly(carbonate)(PC) 의 산화전위와 전류밀도를 측정하였다. Tafel 기울기는 분극곡선의 Tafel polt으로부터 결정되어졌다. 전달게수 ${\alpha}$는 기울기 (1-${\alpha}$)nF/2.3RT에서 얻어질 수 있고 인식된 전극 반응은 모든 조건에서 비가역적으로 나타났다.

• Bulletin of the Korean Chemical Society
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• 제18권9호
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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.

• 대한화학회지
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• 제51권1호
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• pp.14-20
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• 2007

금(Au) 전극 위에 전해 석출한 철족 원소(Fe, Co, Ni)를 전극으로 phthalate 완충 용액에서 철족 원소의 부식과정을 조사하였다. Phthalate 완충용액의 pH의 변화에 대한 부식전위와 부식전류를 측정하여 각 원소(Fe, Co, Ni)전극의 산화반응과 환원반응에 대한 Tafel 기울기를 구하였으며 Tafel 기울기를 포함한 정량적인 전기화학 인자를 측정하여 전극의 산화반응과 환원반응에 대한 반응 메커니즘을 제안하였다. Phthalate 완충 용액에 존재하는 화학 종의 흡착은 철족 원소 전극의 산화반응에 영향을 미치는 것으로 보인다.

• Journal of Electrochemical Science and Technology
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• 제13권4호
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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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• 제4권2호
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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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• 제10권S_1호
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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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• 제3권3호
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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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• 제10권S_4호
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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.