| Texto completo | |
| Autor(es): |
Torresi, Roberto M.
[1]
;
Lodovico, Lucas
[1]
;
Benedetti, Tania M.
[1]
;
Alcantara, Maria R.
[1]
;
Debiemme-Chouvy, Catherine
[2]
;
Deslouis, Claude
[2]
Número total de Autores: 6
|
| Afiliação do(s) autor(es): | [1] Univ Sao Paulo, Inst Quim, BR-05513970 Sao Paulo - Brazil
[2] Univ Paris 06, LISE UPR CNRS 15, F-75252 Paris - France
Número total de Afiliações: 2
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Electrochimica Acta; v. 93, p. 32-43, MAR 30 2013. |
| Citações Web of Science: | 5 |
| Resumo | |
In this work, the role of convective mass transport in two ionic liquids (ILs) that differ by the anions 1-butyl-2,3-dimethyl-imidazolium bis(trifluoromethanesulfonyl)imide ({[}BMMI]{[}Tf2N]) and 1-butyl-2,3-dimethyl-imidazolium tetrafluorborate ({[}BMMI]{[}BF4]) were studied in the presence of ferrocene (Fe) as a redox tracer. A rotating disk electrode (RDE) system was used, and the use of electrochemical (EIS) and electrohydrodynamic (EHD) impedance spectroscopies allowed for a deeper analysis of mass transport and charge transfer at the surface of the electrode. The two ILs showed a viscoelastic character that was observed using a parallel plate geometry viscometer with a high storage-to-loss modulus ratio in a frequency domain where the RDE response was characterized by significant elongational flow kinematics. As a general conclusion, the observed effects were interpreted as unbalanced contributions of the elongational flow close to the electrode surface, which induced an anisotropic diffusivity that increased along the flow lines, and the effect of Fc and Fc(+) as structure breakers or strengtheners in the diffusion layer. Finally, from EIS analysis, it was established that increasing the overpotential in the anodic direction yielded an increased Schmidt number, which indicated a detrimental effect on the mass transport of Fc(+), whose production rate was also increased under the same conditions. EIS showed that the anion had an effect on the reaction rate of Fc oxidation and on the double-layer capacitance value. (C) 2013 Elsevier Ltd. All rights reserved. (AU) | |
| Processo FAPESP: | 09/53199-3 - Reconhecimento molecular e armazenamento de energia: estudos fundamentais do efeito de geometria, tamanho e síntese na otimização das propriedades químicas de materiais eletroativos |
| Beneficiário: | Roberto Manuel Torresi |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |
| Processo FAPESP: | 12/02117-0 - Uso de poli(líquidos iônicos) em dispositivos eletroquímicos: produção de polieletrólitos para dispositivos de armazenamento e conversão de energia e estabilização de grafeno e poli(3,4-etilenodioxitiofeno) (PEDOT) para fabricação de filmes eletroativos |
| Beneficiário: | Tania Machado Benedetti |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |
| Processo FAPESP: | 09/08178-8 - Estudo de propriedades de transporte de espécies eletroativas em líquidos iônicos |
| Beneficiário: | Roberto Manuel Torresi |
| Modalidade de apoio: | Bolsas no Exterior - Pesquisa |
| Processo FAPESP: | 11/16078-3 - Eletroquímica de grafenos em líquidos iônicos |
| Beneficiário: | Lucas Lodovico de Carvalho |
| Modalidade de apoio: | Bolsas no Brasil - Mestrado |