Structure, dynamics and conductivities of ionic liquid-alcohol mixtures
| Autor: | José M. Otero-Mato, Hadrián Montes-Campos, Víctor Gómez-González, Martín Montoto, Oscar Cabeza, Svyatoslav Kondrat, Luis M. Varela |
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| Přispěvatelé: | Universidade de Santiago de Compostela. Departamento de Física de Partículas |
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | RUC. Repositorio da Universidade da Coruña instname Minerva. Repositorio Institucional de la Universidad de Santiago de Compostela Journal of Molecular Liquids |
| Popis: | [Abstract] We study the microscopic structure and transport properties of ions in mixtures of 1-butyl-3-methylimidazolium and 1-butyl-3-ethylimidazolium iodide with ethanol using atomistic molecular dynamics simulations and conductivity measurements. Compared with the same ionic liquids in water, we reveal essential differences in ionic structure that are closely related to the differences in the solubility mechanisms of both types of solvents. In particular, unlike for aqueous solutions, we find a homogeneous distribution of solvent molecules in the system, i.e., we observe no cluster formation, which agrees with the nano-structured solvation paradigm. In addition, we calculate the conductivities of these systems in the whole concentration range and compare them with experimental data. Although the simulated values slightly underestimate the experimental ones, they reproduce the shape of the experimental conductivity dome reasonably well. We also show that the pseudo-lattice random-alloy model, which is based on microscopic ion jumping frequencies, describes the conductivity data accurately. We compute the average jumping frequencies directly from simulations and find that they agree well with those obtained by fitting the simulation conductivity data. These results show that the pseudo-lattice random-alloy model provides a valuable tool to describe the conductivities of ionic liquid–solvent mixtures and particularly their concentration dependence. It shall also apply to other systems, e.g., inorganic electrolytes and dispersed ionic conductors. The financial support of the Spanish Ministry of Economy and Competitiveness (Projects MAT2017-89239-C2-1-P and MAT2017-89239- C2-2-P) is gratefully acknowledged. Moreover, this work was funded by the Xunta de Galicia (ED431D 2017/06, ED431E 2018/08, GRC ED431C 2016/001 and GRC ED431C 2020/10). All these research projects were partially supported by FEDER. The help of the technician M. C. V. from UDC for some of the measurements presented is also acknowledged. H. M-C. and J. M. O-M. thank the Spanish Ministry of Education for their FPU grant, and H. M-C. thanks the USC for his “Convocatoria de Recualificación do Sistema Universitario Español-Margarita Salas” postdoc grant under the “Plan de Recuperación Transformación” program funded by the Spanish Ministry of Universities with European Union’s NextGenerationEU funds Xunta de Galicia; ED431D 2017/06 Xunta de Galicia; ED431E 2018/08 Xunta de Galicia; ED431C 2016/001 Xunta de Galicia; ED431C 2020/10 |
| Databáze: | OpenAIRE |
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