Rheological Changes and Kinetics of Water Uptake by Poly(ionic liquid)-Based Thin Films

Autor(es)

Benedetti, Tania M. ^[1] ; Torresi, Roberto M. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Quim, BR-05513970 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Langmuir; v. 29, n. 50, p. 15589-15595, DEC 17 2013.
• Citações Web of Science: 16

Resumo

Water uptake by thin films composed of the poly(ionic liquid) poly{[}diallyldimethylammonium bis(trifluoromethanesulfonyl)imide] (PDDATf(2)N) and the ionic liquid N,N-butylmethylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr(1.4)Tf(2)N) was studied with a quartz crystal microbalance with dissipation. The data obtained for films with different compositions during the passage of dry and wet N-2 flow through the films were simulated with the Kevin-Voigt viscoelastic model for assessment of the mass of uptake water as well as the viscoelastic parameters. Our results show that the ionic liquid acts as a plasticizer, reducing the rigidity of the film and decreasing the capacity of water uptake. Introduction to a Li salt (LiTf2N) increases the water uptake capacity and also affects both elastic and viscous parameters due to aggregation among the ions from the ionic liquid and Li+. However, due to the preferable interaction of Li+ ions with water molecules, these aggregates are broken when the film is hydrated. In short, the presence of water in such films affects their mechanical properties, which can reflect in their performances as solid state electrolytes and ion-conducting membranes for electrochemical applications. (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
• Linha de fomento: 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
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado