United atom model for ionic liquids: UAM-IL

Martínez-Jiménez, Manuel; Serrano-Ocaña, Martha; Alejandre, José

doi:10.1016/j.molliq.2021.115488

Cited by 6 publications

(3 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here we would like to remark that the charges of ions in liquid water, applied in the scaled particle model, is also about 75%–80% of the nominal charge [68–71]. On the other hand, there are some other works in the literature that suggest the usage of the nominal charge of monovalent cations for simulating ionic liquids and electrolyte solutions [72,73].…”

Section: Resultsmentioning

confidence: 99%

The influence of cations on the dipole moments of neighboring polar molecules

Bakó

Csókás

Mayer

et al. 2021

Int J of Quantum Chemistry

View full text Add to dashboard Cite

In this article we show how the dipole moment of a single molecule in a cluster can be calculated and used for describing the polarization effect. Additionally, we review the accuracy of the calculation of the dipole moment of several simple protic and aprotic molecules. It is shown that the dipole moment of polar (water, methanol, formamide, acetone and acetonitrile) molecules in the neighborhood of a cation is increased primarily by polarization from the bare electrostatic charge of the cation, although the effective value of the latter is somewhat reduced by "back donation" of electrons from neighboring polar molecules. In other words, the classical picture may be viewed as if a point charge slightly smaller than the nominal charge of the cation would be placed at the cation site. It was found that the geometrical arrangement of the polar molecules in the first solvation shell is such that their mutual polarization reduces the dipole moments of individual molecules, so that in some cases they become smaller than the dipole moment of the free protic or aprotic molecule. We conjecture, for the first time, that this behavior, namely the about 10%-20% decrease of the dipole moment of water in the first shell of cations, with the cation itself removed, is essentially a manifestation of the Le Chatelier-Braun principle. We also remark that if the cation-molecule bond order is too large then the calculated dipole moment for these complexes can be questionable, due to the questionable definition of a single molecule within the "supermolecule"-like cluster.

show abstract

Section: Resultsmentioning

confidence: 99%

The influence of cations on the dipole moments of neighboring polar molecules

Bakó

Csókás

Mayer

et al. 2021

Int J of Quantum Chemistry

View full text Add to dashboard Cite

show abstract

“…Bedrov et al provide an excellent introduction and discussion to polarizable force fields, and we will not discuss these further. Technical aspects connected to the computation of electrostatic interactions using polarizable ions were discussed by Coretti et al We note, however, that good agreement between simulation and experiment was obtained using nonpolarizable models by reparametrizing atomistic force fields, , as well as using coarse grained models. ,, …”

Section: Simulationsmentioning

confidence: 97%

“…Bedrov et al 215 provide an excellent introduction and discussion to polarizable force fields, and we will not discuss these further. Technical aspects connected to the computation of electrostatic interactions using polarizable ions were discussed by Coretti et al 264 We note, however, that good agreement between simulation and experiment was obtained using nonpolarizable models by reparametrizing atomistic force fields, 243,277 as well as using coarse grained models. 210,239,240 The accurate modeling of the dynamic properties is also desirable to reproduce the right times scales associated with the cooperative behavior of RTILs and dynamical processes such as lubrication in nanoscale gaps.…”

mentioning

confidence: 88%

Theory and Simulations of Ionic Liquids in Nanoconfinement

et al. 2023

View full text Add to dashboard Cite

Room-temperature ionic liquids (RTILs) have exciting properties such as nonvolatility, large electrochemical windows, and remarkable variety, drawing much interest in energy storage, gating, electrocatalysis, tunable lubrication, and other applications. Confined RTILs appear in various situations, for instance, in pores of nanostructured electrodes of supercapacitors and batteries, as such electrodes increase the contact area with RTILs and enhance the total capacitance and stored energy, between crossed cylinders in surface force balance experiments, between a tip and a sample in atomic force microscopy, and between sliding surfaces in tribology experiments, where RTILs act as lubricants. The properties and functioning of RTILs in confinement, especially nanoconfinement, result in fascinating structural and dynamic phenomena, including layering, overscreening and crowding, nanoscale capillary freezing, quantized and electrotunable friction, and superionic state. This review offers a comprehensive analysis of the fundamental physical phenomena controlling the properties of such systems and the current state-of-the-art theoretical and simulation approaches developed for their description. We discuss these approaches sequentially by increasing atomistic complexity, paying particular attention to new physical phenomena emerging in nanoscale confinement. This review covers theoretical models, most of which are based on mapping the problems on pertinent statistical mechanics models with exact analytical solutions, allowing systematic analysis and new physical insights to develop more easily. We also describe a classical density functional theory, which offers a reliable and computationally inexpensive tool to account for some microscopic details and correlations that simplified models often fail to consider. Molecular simulations play a vital role in studying confined ionic liquids, enabling deep microscopic insights otherwise unavailable to researchers. We describe the basics of various simulation approaches and discuss their challenges and applicability to specific problems, focusing on RTIL structure in cylindrical and slit confinement and how it relates to friction and capacitive and dynamic properties of confined ions.

show abstract