Author(s): Carneiro, J. ; Tedim, J. ; Fernandes, S. C. M. ; Freire, C. S. R. ; Silvestre, A. J. D. ; Gandini, A. ; Ferreira, M. G. S. ; Zheludkevich, M. L.
Date: 2012
Persistent ID: http://hdl.handle.net/10773/9006
Origin: RIA - Repositório Institucional da Universidade de Aveiro
Subject(s): Cerium (III); Chitosan; Corrosion protection; Self-healing; AA2024
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.
