• Title/Summary/Keyword: anodic current. Tafel

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

  • Choi, Chil-Nam;Yang, Hyo-Kyung
    • 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.

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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    • 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.

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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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    • 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.

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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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    • 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.

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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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    • v.4 no.4
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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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    • v.4 no.1
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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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    • v.4 no.3
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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
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2001.11a
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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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Anodic Dissolution of Electrodeposited Iron Group Elements in Phthalate Buffer Solution (Phthalate 완충용액에서 전해 석출한 철족 원소의 산화 용해 반응)

  • Chon, Jung-Kyoon;Kim, Youn-Kyoo
    • 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.

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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    • v.2 no.2
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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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