Influence of the Water Content on the Structure and Physicochemical Properties of an Ionic Liquid and Its Li+ Mixture

Autor(es)

Martins, Vitor L. ^[1] ; Nicolau, Bruno G. ^[1] ; Urahata, Sergio M. ^[2] ; Ribeiro, Mauro C. C. ^[1] ; Torresi, Roberto M. ^[1]

Afiliação do(s) autor(es)

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

^[2] Univ Sao Paulo, Inst Fis, BR-05513970 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Physical Chemistry B; v. 117, n. 29, p. 8782-8792, JUL 25 2013.
• Citações Web of Science: 26

Resumo

The effect of water on the hydrophobic ionic liquid (IL) 1-n-butyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonylimide) and its Li+ mixture was evaluated. The electrochemical stability, density, viscosity, and ionic conductivity were measured for both systems in different concentrations of water. The presence of Li+ causes a large increase in the water absorption ability of the IL. The experimental results suggest a break of the interactions between Li+ and Tf2N- anions in the strong aggregates formed in dried Li+ mixtures, modifying the size and physicochemical nature of these aggregates. It is also observed that the size of the ions aggregates with formal charge increases at high temperature and decreases the mobility of the charge carrier, explaining the break in the Walden rules at high temperature. Raman spectroscopy and molecular dynamic simulations show the structural change of these systems. In neat ILs, the water molecules interact mainly among each other, while in the Li+ mixtures, water interacts preferentially with the metallic cation, causing an important change in the aggregates present in this system. (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: 09/09209-4 - Eletrodeposição de metais utilizando líquidos iônicos
• Beneficiário: Vitor Leite Martins
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto