Charge Transport and Phase Behavior of Imidazolium-Based Ionic Liquid Crystals from Fully Atomistic Simulations

Abstract

Ionic liquid crystals occupy an intriguing middle ground between room-temperature ionic liquids and mesostructured liquid crystals. Here, we examine a non-polarizable, fully atomistic model of the 1-alkyl-3-methylimidazolium nitrate family using molecular dynamics in the constant pressure–constant temperature ensemble. These materials exhibit a distinct “smectic” liquid phase, characterized by layers formed by the molecules, which separate the ionic and aliphatic moieties. In particular, we discuss the implications this layering may have for electrolyte applications.

Correction: Quevillon, M.J., et al. Charge Transport and Phase Behavior of Imidazolium-Based Ionic Liquid Crystals from Fully Atomistic Simulations. Materials 2018, 11, 64

“…In our publication [ 1 ], we performed classical molecular dynamics simulations of a system of ionic liquid crystals using a transferable OPLS-AA force field [ 2 ] specifically developed for ionic liquids. In performing subsequent research, we became aware of a paper [ 3 ] performed by the same authors as reference [ 2 ], which updates some of the force field parameters for molecular dynamics simulations.…”

“…However, the functional form of the torsional angles in the newer paper [ 3 ] was listed in a different form than was used in the original paper of the force field [ 2 ]. This lead us to review the force field that we had implemented in our study [ 1 ] and to determine if this had had significant quantitative or qualitative effects.…”

“…With corrected functional form in the subsequent publication [ 3 ], the authors wish to make corrections to our publication [ 1 ], as well as replace the affected figures. All references to the original force field have been updated to include the subsequent publication.…”

Phase Behaviors of Ionic Liquids Heating from Different Crystal Polymorphs toward the Same Smectic-A Ionic Liquid Crystal by Molecular Dynamics Simulation

“…[3]. Their thermotropic phase behavior, as an essential physical property, has been investigated by both experiments [3][4][5][6][7][8][9][10][11][12] and simulations [13][14][15][16][17]. In experiments, IL samples usually undergo several heating-cooling cycles, heated from a crystal phase to reach LC and/or liquid phases and then cooled down to recrystallize, during which crystal polymorphism is often reported, which is potentially of great importance in materials science and industry because physiochemical properties of polymorphs, such as thermal stability [6,9,18], ion conductivity [9,12], etc., can significantly affect productions and applications of ILs and ILCs.…”

“…From a simulation viewpoint, there are two convenient ways to obtain ILC structures. One is from heating a crystal structure [13][14][15][20][21][22], and another is through simulated annealing processes [17,23]. For the first way, the initial crystal structures are either handmade or from experimental data and may differ from one work to another, exhibiting the existence of crystal polymorphs.…”