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

Abstract

<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>

Unravelling the Interactions between Surface-Active Ionic Liquids and Triblock Copolymers for the Design of Thermal Responsive Systems

“…They are based on the MARTINI framework, with appropriate adaptations for the specific systems studied here. The applicability and transferability of the MARTINI CG approach have been widely documented in the recent literature, − and the reader is referred to those studies for additional details. Regarding the phosphonium CG model, the regular MARTINI water was used bearing in mind the high computational costs of simulating systems with MARTINI polarizable water, 4 times longer compared with regular water, , and the PME to cope with the electrostatics requiring ∼3 times longer than cutoff treatment, both heavily increasing the simulation time.…”

Martini 3: a general purpose force field for coarse-grained molecular dynamics

“…Based on this new foundation, further optimizations for different classes of molecules are currently ongoing, including the use of Gō-potentials to alleviate limitations of protein conformational flexibility, a re-optimization of the bonded potentials of lipids and other biomolecular classes, as well as a compatible polarizable water model for applications requiring more realistic screening of electrostatic interactions. Finally, we foresee new application horizons for the Martini model in the field of materials science64,65 and high-throughput drug design66 . EP/P021123/1.…”

Two decades of Martini: Better beads, broader scope

“…Liquid–liquid partitioning involving water/hexadecane, water/chloroform, and water/octanol biphasic systems showed a mean absolute error compared to experimental data of around 2–3 kJ/mol (Figure 4a). 83,169 At the same time, liquid–liquid mixing behavior was captured accurately, from common solvents 83,169 (Figure 4b) to complex mixtures involving small conjugated molecules, 173 coacervates, 89 ionic liquids, 86 and deep eutectic solvents 88 . As a direct consequence of the improved calibration of the cross‐interactions between the different bead sizes, large dimerization dissociation barrier artifacts between cyclic molecules previously observed in Martini 2 no longer exist 83,169 .…”