resumo
The good film forming ability, specific solubility and versatile chemical functionalization of chitosan make it a promising candidate for "green" protective coatings. In the present work, these features are exploited together with chitosan high complexing ability to obtain inhibitor-containing anticorrosion coatings for active protection of aluminum alloys. The functionalization of chitosan with fluorinated substituents was also evaluated as a possible route to improve barrier and surface properties of the coating matrix. It was observed that the chitosan layer worked as a reservoir for cationic Ce3+ corrosion inhibitor due to the complexation of Ce3+ with chitosan amino groups, which prevents its uncontrollable and fast leaching. These Ce-containing coatings were found to confer active corrosion protection toward aluminum alloy 2024 as shown by electrochemical impedance spectroscopy. Moreover, the corrosion tests evidence the self-healing ability of prepared chitosan-based "green" protective coatings. The interaction between Ce3+ and chitosan and the concentration effect of the former on the performance of the latter from a corrosion standpoint is also discussed. (C) 2012 Elsevier B.V. All rights reserved.
palavras-chave
CHITIN; DEPOSITION
categoria
Chemistry; Materials Science
autores
Carneiro, J; Tedim, J; Fernandes, SCM; Freire, CSR; Silvestre, AJD; Gandini, A; Ferreira, MGS; Zheludkevich, ML
nossos autores
Alessandro Gandini
Investigador
Armando Jorge Domingues Silvestre
Professor Catedrático
Carmen Sofia da Rocha Freire Barros
Investigador Coordenador
João Tedim
Professor associado
Jorge Augusto Oliveira Carneiro
Bolseiro de pós-Doutoramento
Mário Guerreiro Silva Ferreira
Professor(a) Jubilado(a)
Mikhail Zheludkevich
Investigador Principal ConvidadoGrupos
G3 - Materiais Eletroquímicos, Interfaces e Revestimentos
G4 - Materiais Renováveis e Economia Circular
agradecimentos
The authors gratefully acknowledge the financial support of CICECO (Financiamento Programatico da UI 89 CICECO). JT thanks FCT for post-doctoral grant (ref. SFRH/BPD/64335/2009).