Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1471295 | Corrosion Science | 2008 | 7 Pages |
Abstract
A film of two-dimensional polymer was prepared on an iron electrode passivated in a borate buffer solution at pH 8.49, derivatized with 16-hydroxyhexadecanoate ion HO(CH2)15CO2- and then modified with 1,2-bis(triethoxysilyl)ethane (C2H5O)3Si(CH2)2Si(OC2H5)3 and octadecyltriethoxysilane C18H37Si(OC2H5)3. The protective ability of the polymer film adsorbed on passivated iron was examined by polarization measurement in oxygenated 0.1Â M KClO4 solutions with and without 1Â ÃÂ 10â4 and 1Â ÃÂ 10â3Â M of Clâ. The values of the open-circuit potential, Eoc were monitored with the immersion time, t in these solutions. The Eoc value of the passivated electrode in 0.1Â M KClO4 was maintained high, more than â0.2Â V/SCE in the initial region of t up to 10Â h, indicating the presence of a passive film on the electrode. Thereafter, Eoc decreased to â0.4Â V/SCE abruptly, exhibiting breakdown of the passive film. The value of the passivated electrode covered with the polymer film remained almost constant around â0.04Â V/SCE during immersion for 45Â h. The protective efficiency, P (%) of the polymer film on passivated iron was extremely high, more than 99.9% unless the passive film was broken down, indicating complete protection of iron against corrosion. The times for breakdown on the passivated electrode and polymer-coated one diminished with an increase in the concentration of Clâ. The polymer-coated surface was analyzed by electron-probe microanalysis after immersion in 0.1Â M KClO4 for 24Â h.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Kunitsugu Aramaki, Tadashi Shimura,