Conditional Reversible Work Coarse-Grained Models with Explicit Electrostatics—An Application to Butylmethylimidazolium Ionic Liquids

Abstract Due to their complex molecular structures and interactions, phase behaviors of complex fluids are quite often difficult to be identified by common phase transition analysis methods. Percolation phase transition, on the other hand, only monitors the degree of connection among particles without strict geometric requirements such as translational or orientational order, and thus suitable for pinpointing phase transitions of complex fluids. As typical complex fluids, ionic liquids (ILs) exhibit phases beyond the description of simple liquid theories. In particular, with an intermediate cationic side-chain length, ILs can form the nanoscale segregated liquid (NSL) state, which will eventually transform into the ionic liquid crystal (ILC) structure when the side chains are adequately long. However, the microscopic mechanism of this transformation is still unclear. In this work, by means of coarse-grained molecular dynamics simulation, we show that, with increasing cationic side-chain length, some local pieces of non-polar domains are gradually formed by side chains aligned in parallel inside the NSL phase, before an abrupt percolation phase transition happens when the system transforms into the ILC phase. This work not only identifies that the NSL to ILC phase transition is a critical phenomenon, but also demonstrates the importance of percolation theory to complex fluids.

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Solid-liquid work of adhesion of coarse-grained models of n-hexane on graphene layers derived from the conditional reversible work method

The Journal of Chemical Physics ◽

10.1063/1.4936253 ◽

2015 ◽

Vol 143 (24) ◽

pp. 243135 ◽

Cited By ~ 16

Author(s):

Vikram Reddy Ardham ◽

Gregor Deichmann ◽

Nico F. A. van der Vegt ◽

Frédéric Leroy

Keyword(s):

Work Of Adhesion ◽

Coarse Grained ◽

Graphene Layers ◽

Solid Liquid ◽

Work Method ◽

Reversible Work

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Combining non-equilibrium simulations and coarse-grained modelling allows for a fine-grained decomposition of solvation dynamics

Physical Chemistry Chemical Physics ◽

10.1039/c6cp06282b ◽

2016 ◽

Vol 18 (45) ◽

pp. 30954-30960 ◽

Cited By ~ 5

Author(s):

Michael Schmollngruber ◽

Daniel Braun ◽

Othmar Steinhauser

Keyword(s):

Ionic Liquids ◽

Stokes Shift ◽

Time Dependent ◽

Coarse Grained ◽

Solvation Dynamics ◽

Fine Grained ◽

Non Equilibrium

The time-dependent Stokes shift is shown to be a localized and short-ranged effect in ionic liquids.

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Dynamical properties across different coarse-grained models for ionic liquids

Journal of Physics Condensed Matter ◽

10.1088/1361-648x/abe6e1 ◽

2021 ◽

Author(s):

Joseph F. Rudzinski ◽

Sebastian Kloth ◽

Svenja Wörner ◽

Tamisra Pal ◽

Kurt Kremer ◽

...

Keyword(s):

Ionic Liquids ◽

Coarse Grained ◽

Dynamical Properties

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Martini Coarse-Grained Models of Imidazolium-Based Ionic Liquids: From Nanostructural Organization to Liquid-Liquid Extraction

10.26434/chemrxiv.12369479 ◽

2020 ◽

Author(s):

Luis Itza Vazquez-Salazar ◽

Michele Selle ◽

Alex H. de Vries ◽

Siewert-Jan Marrink ◽

Paulo C. T. Souza

Keyword(s):

Ionic Liquids ◽

Force Field ◽

Rational Design ◽

Value Added ◽

Liquid Extraction ◽

Coarse Grained ◽

Great Success ◽

Liquid Liquid Extraction ◽

Martini Force Field ◽

Wide Range

<div> <div> <div> <p>Ionic liquids (IL) are remarkable green solvents, which find applications in many areas of nano- and biotechnology including extraction and purification of value-added compounds or fine chemicals. These liquid salts possess versatile solvation properties that can be tuned by modifications in the cation or anion structure. So far, in contrast to the great success of theoretical and computational methodologies applied to other fields, only a few IL models have been able to bring insights towards the rational design of such solvents. In this work, we develop coarse-grained (CG) models for imidazolium-based ILs using a new version of the Martini force field. The model is able to reproduce the main structural properties of pure ILs, including spatial heterogeneity and global densities over a wide range of temperatures. More importantly, given the high intermolecular compatibility of the Martini force field, this new IL CG model opens the possibility of large-scale simulations of liquid-liquid extraction experiments. As examples, we show two applications, namely the extraction of aromatic molecules from a petroleum oil model and the extraction of omega-3 polyunsaturated fatty acids from a fish oil model. In semi-quantitative agreement with the experiments, we show how the extraction capacity and selectivity of the IL could be affected by the cation chain length or addition of co-solvents. </p> </div> </div> </div>

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