• 제목/요약/키워드: anodic current. Tafel

검색결과 35건 처리시간 0.016초

고분자물질들의 분극 특성: Poly(vinylchloride), Poly(ethyleneterephthalate), Poly(propylene), Poly(carbonate) (Polarization Characteristics of Polymers: Poly(vinylchloride), Poly(ethyleneterephthalate), Poly(propylene), and Poly(carbonate))

  • 최칠남;양효경
    • 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.

Affect of Corrosion Potential and Current Density on Polarization Curves Variations of Polyvinylchloride[II]

  • Park, Chil-Nam;Yang, Hyo-Kyung;Kim, Sun-Kyu
    • 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.

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Redox Reaction of Poly(ethyleneterephthalate) Polymer in Aprotic Solvent

  • Choi, Chil-Nami
    • 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.

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Corrosion Characteristics with Polarization Curve of Polymers

  • Park, Chil-Nam;Jung, Oh-Jin
    • 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.

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Influence of Redox Potential Current Density on Polarization Curves with Polypropylene Polymer

  • Park, Chil-Nam;Kim, Myung-Sun
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • 제4권4호
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    • pp.255-261
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    • 2000
  • Experiments were carried out to measure the corrosion potential and current density variations in the polarization curves of polypropylene. In particular, the results were examined to identify those influences affecting the corrosion potential, such as temperature, pH, salt, and oxygen. The Tafel slope for the anodic dissolution was determined based on the polarization effect under various conditions. Furthermore, the optimum conditions for the most rapid transformation were establish based on a variety of conditions, including temperature, pH, corrosion rate, and resistance of corrosion potential. The second anodic current density peak and maximum passive current density were designated as the critical corrosion sensitivity(I(sub)r/I(sub)f). This I(sub)r/I(sub)f value was then used to measure the critical corrosion sensitivity of polypropylene. The potentiodynamic parameters of corrosion were obtained using a Tafel plot.

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Influence of Corrosion Potential and Current Density on Polarization Curve Variations using Polycarbonate[III]

  • Park, Chil-Nam;Yang, Hyo-Kyung;Kim, Sun-Kyu;Kim, Myung-Sun;Cheong, Kyung-Hoon
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • 제4권1호
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    • pp.43-50
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    • 2000
  • In this study, experiments were carried out to measure the variations in the corrosion potential and current density of polarization curves using polycarbonate. The results were particularly examined to identify the influences affecting the corrosion potential including various conditions such as temperature, pH, catalytic enzyme, and salt. The lines representing the 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 based on the polarization effect with various conditions. The slope of the polarization curves describing the active-to-passive transition region were noticeably shifted in direction. Also, from the variation in the conditions, the optimum conditions were established for the most rapid transformation, including temperature, pH, corrosion rate, and resistance of corrosion potential. The second anodic current density peak and maximum passive current density were designated as the critical corrosion sensitivity(Ir/If). The value of Ir/If was then used in measuring the extent of the critical corrosion sensitivity of the polycarbonate. The potentiodynamic parameters of the corrosion were obtained using a Tafel plot.

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Redox Reaction on Polarization Curve Variations of Polymer with Enzymes

  • Park, Chil-Nam
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • 제4권3호
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    • pp.165-171
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    • 2000
  • Experiments were carried out to measure variations in the oxidation potential and current density using the polarization curves of polycarbonate. The results were then examined to identify the influences affecting the oxidation potential related to various conditions, such as temperature, pH, and oxydase(citrate and lipase). The lines representing the active anodic and cathodic dissolution shifted only slightly in the potential direction relative to temperature, pH, and the effect of the enzyme. The Tafel slope for the anodic and cathodic dissolution was determined such that the reversibility polarization was indicated as being effected by various conditions. The slope of the polarization curves describing the active-to-passive transition region shifted noticeably in their direction. Also, by varying the conditions, the optimum conditions for the most ready transform were identified, including temperature, pH, oxidation rate, and resistance of oxidation potential. The critical oxidation sensitivity(I(sub)r/I(sub)f) of the anodic current density peak and maximum passive current density was also determined, which is used in measuring the critical corrosion sensitivity of a polycarbonate.

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Comparison with Polarization Characteristic of Polymers

  • Choi, Chil-Nam;Yabg, Hyo-Kyung
    • 한국환경과학회:학술대회논문집
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    • 한국환경과학회 2001년도 가을 학술발표회 발표논문집
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    • pp.188-190
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    • 2001
  • We carried out to measure the variations of potential with current density polymers. The results were particularly examined to identify the influences on corrosion potential and corrosion 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 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.

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Phthalate 완충용액에서 전해 석출한 철족 원소의 산화 용해 반응 (Anodic Dissolution of Electrodeposited Iron Group Elements in Phthalate Buffer Solution)

  • 천정균;김연규
    • 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.

Affecting of Corrosion Potential and Current Density on Variation Polarization Curves with Polyvinylchloride (I)

  • Choi, Chil-Nam;Yang, Hyo-Kyung;Jung, Oh-Jin
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • 제2권2호
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    • pp.91-98
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    • 1998
  • In this study, we carried out the experiments for measuring the variations of corrosion potential and current density for polarization curves with polyvinylchloride. The results exhibited especially the influence affecting the corrosion potential and various conditions (temperature, day, pH, bacteria, and added salt). The second anodic current density peak and the minimum passive current density are designated $I_P/I_0,$ respectively. The value of $I_P/I_O$ is used as a measurement for the extent of degradation of the polyvinylchloride. The potentiodpnamics parameters of the corrosion were obtained using Tafel equation.

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