TY - JOUR
T1 - Improvement of healing treatment with NaNO3 for a passivated iron electrode covered with an ultrathin polymer coating to prevent iron corrosion in some solutions containing aggressive anions
AU - Aramaki, Kunitsugu
AU - Shimura, Tadashi
PY - 2011/12/1
Y1 - 2011/12/1
N2 - An ultrathin and ordered polymer coating was prepared on a passivated iron electrode by modification of a 16-hydroxyhexadecanoate ion HO(CH2)15CO2- self-assembled monolayer with 1,2-bis(triethoxysilyl)ethane (C2H5O)3Si(CH2)2Si(OC2H5)3 and octyltriethoxysilane C8H17Si(OC2H5)3. Further, the passivated and polymer-coated electrode was healed by treatment in 1.0M NaNO3 for 4h. Prevention of passive film breakdown and iron corrosion for the passivated, polymer-coated and healed electrode was examined by monitoring of the open-circuit potential and repeated polarization measurements in oxygenated 0.1M KClO4, 0.1M Na2SO4 and 0.1M NaCl for many hours. The values of the time for passive film breakdown, tbd were >240, 22.2 and 9.5h in these solutions, respectively. The protective efficiencies for the electrode were extremely high, more than 99.9% before tbd, indicating complete protection of substrate iron against corrosion in these solutions, unless passive film breakdown occurred. The presence of NO3- on the passive surface by treatment in 1.0M NaNO3 was detected by X-ray photoelectron and FTIR reflection spectroscopies. The self-healing activity of adsorbed NO3- to suppress passive film breakdown was discussed.
AB - An ultrathin and ordered polymer coating was prepared on a passivated iron electrode by modification of a 16-hydroxyhexadecanoate ion HO(CH2)15CO2- self-assembled monolayer with 1,2-bis(triethoxysilyl)ethane (C2H5O)3Si(CH2)2Si(OC2H5)3 and octyltriethoxysilane C8H17Si(OC2H5)3. Further, the passivated and polymer-coated electrode was healed by treatment in 1.0M NaNO3 for 4h. Prevention of passive film breakdown and iron corrosion for the passivated, polymer-coated and healed electrode was examined by monitoring of the open-circuit potential and repeated polarization measurements in oxygenated 0.1M KClO4, 0.1M Na2SO4 and 0.1M NaCl for many hours. The values of the time for passive film breakdown, tbd were >240, 22.2 and 9.5h in these solutions, respectively. The protective efficiencies for the electrode were extremely high, more than 99.9% before tbd, indicating complete protection of substrate iron against corrosion in these solutions, unless passive film breakdown occurred. The presence of NO3- on the passive surface by treatment in 1.0M NaNO3 was detected by X-ray photoelectron and FTIR reflection spectroscopies. The self-healing activity of adsorbed NO3- to suppress passive film breakdown was discussed.
KW - A. Iron
KW - B. Polarization
KW - C. Neutral inhibition
KW - C. Passive films
KW - C. Polymer coatings
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U2 - 10.1016/j.corsci.2011.08.025
DO - 10.1016/j.corsci.2011.08.025
M3 - Article
AN - SCOPUS:80053457850
VL - 53
SP - 4152
EP - 4158
JO - Corrosion Science
JF - Corrosion Science
SN - 0010-938X
IS - 12
ER -