abstract
Negative-feedback scanning electrochemical microscopy (SECM) is successfully applied to visualize spatially resolved differences in the topography of coated metal samples upon exposure to aqueous electrolyte solutions of different composition. This method allows the investigation of the uptake of reactants from the electrolyte phase through the polymeric matrix to the metal/polymer interface to be performed even at early exposures. Yet, the method must be carefully checked to discard transport processes from the organic matrix into the solution phase, such as those related to lixiviation. In this later case, the topography of the polymer layer may evolve with time accordingly, not longer exclusively responding to the uptake by the polymer matrix of components from the electrolyte phase. Furthermore, lixiviated species may also react with the SECM tip, eventually leading to the continuous modification of the active surface area of the electrode during the measurements. In this work, the effect of lixiviation from a nickel foil coated with plasticized PVC (PVC Plastisol) on its topographic characterization by SECM was investigated. (C) 2011 Elsevier B.V. All rights reserved.
keywords
SCANNING ELECTROCHEMICAL MICROSCOPY; EIS
subject category
Chemistry; Materials Science
authors
Duarte, RG; Gonzalez, S; Castela, AS; Ferreira, MGS; Souto, RM
our authors
Mário Guerreiro Silva Ferreira
Retired Professoracknowledgements
The authors are grateful to the Ministerio de Ciencia e Innovacion (Madrid, Spain) and the European Regional Development Fund (Brussels, Belgium), within the framework of Project CTQ2009-14322, under which the present work was carried out. R.G.D. is grateful to FCT (Lisbon, Portugal) under POCI 2010 program for the award of a grant to conduct a research stay at the University of La Laguna.