| Texto completo | |
| Autor(es): |
Bernardino, Kalil
;
Ribeiro, Mauro C. C.
Número total de Autores: 2
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Physical Chemistry Chemical Physics; v. 24, n. 11, p. 14-pg., 2022-02-28. |
| Resumo | |
Strong ionic interactions, as well as the consequent correlations between cation and anion dynamics, give ionic liquids various physical features that set them apart from ordinary organic solvents. In particular, they result in larger viscosities and larger densities than mixtures of neutral compounds with similar molecular structures. However, both the direct effect of electrostatic interactions and the increase of liquid density contribute to the high viscosity and so far no experimental or computational work enabled a clear quantification of those effects. Also, the effects over the shear thinning behavior, which may have important consequences for application as lubricants, were not considered yet. Here, these questions were tackled by performing non-equilibrium molecular dynamics (NEMD) simulations changing both the strength of ionic interactions and liquid density at several shear rates using a coarse grained model. The relative dielectric constant was adjusted to reproduce viscosity data from all-atoms simulations on both zero shear and high shear conditions. Elimination of ionic interactions results in a reduction of density and zero shear viscosity and also delays the beginning of shear thinning to higher shear rates. Restoring density to the ionic liquid's value only partially reverses the alterations. Correlations of the non-newtonian behavior and changes in the intermolecular structure and contact lifetimes were also explored. (AU) | |
| Processo FAPESP: | 16/21070-5 - Espectroscopia vibracional com resolução espacial |
| Beneficiário: | Mauro Carlos Costa Ribeiro |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |
| Processo FAPESP: | 17/12063-8 - Dinâmica molecular de não-equilíbrio de líquidos iônicos |
| Beneficiário: | Kalil Bernardino |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |
| Processo FAPESP: | 19/04785-9 - Estudo por dinâmica molecular do efeito da flexibilidade sobre o ponto de fusão de líquidos iônicos |
| Beneficiário: | Kalil Bernardino |
| Modalidade de apoio: | Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado |