resumo
Bis-1,2-[triethoxysilylpropyl]tetrasulfide silane films containing CeO2 center dot ZrO2 nanoparticles were deposited by dip-coating on galvanised steel substrates. The morphological features of the coated substrates were evaluated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The anti-corrosion performance of the modified silane film applied on galvanised steel substrates was studied by electrochemical impedance spectroscopy (EIS). The ability of nanoparticles to mitigate localized corrosion activity at artificially induced defects was investigated via the scanning vibrating electrode technique (SVET) and by the scanning ion-selective electrode technique (SIET). The results showed that the addition of nanoparticles provides good corrosion protection of the galvanised steel substrates pre-treated with the modified silane solutions. The corrosion activity was reduced by more than one order of magnitude. Complementary d.c. experiments, using zinc electrodes exposed to NaCl solutions containing the nanoparticles were also performed in order to better understand the role of the nanoparticles. An ennoblement of the corrosion potential and polarisation of the anodic reactions could be detected. (C) 2008 Elsevier Ltd. All rights reserved.
palavras-chave
SOL-GEL COATINGS; 316L STAINLESS-STEEL; CORROSION-RESISTANCE; ZIRCONIA FILMS; ZRO2-CEO2 FILMS; ALUMINUM-ALLOYS; WET CORROSION; CERIUM; INHIBITORS; PROTECTION
categoria
Electrochemistry
autores
Montemor, MF; Trabelsi, W; Lamaka, SV; Yasakau, KA; Zheludkevich, ML; Bastos, AC; Ferreira, MGS
nossos autores
António Alexandre Cunha Bastos
Investigador Júnior
Kiryl Yasakau
Investigador Auxiliar
Mário Guerreiro Silva Ferreira
Professor(a) Jubilado(a)