The Structure of Aqueous Solutions of a Hydrophilic Ionic Liquid: The Full Concentration Range of 1-Ethyl-3-methylimidazolium Ethylsulfate and Water

Abstract

Several structural features of aqueous solutions of the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate were analyzed in the entire concentration range using molecular dynamics simulation results. Different analysis tools developed in-house were applied to describe the size and connectivity of different water and ion aggregates as a function of the solution concentration. Four concentration ranges-x(H(2)O)<0.5, 0.5<x(H(2)O)<0.8, 0.8<x(H(2)O)<0.95, and x(H(2)O)>0.95-with four distinct structural regimes--isolated water molecules, chain-like water aggregates, bicontinuous system, and isolated ions or small ion clusters--were identified and discussed, including two different percolation limits: that of water in the ionic liquid network (around x(H(2)O)=0.8) and that of the ionic liquid in water (around x(H(2)O)=0.95).

State of Hydrophobic and Hydrophilic Ionic Liquids in Aqueous Solutions: Are the Ions Fully Dissociated?

“…The RDFs obtained in this work are consistent with the results of the present study. The peak height at the CM1 obtained in the present work, however, is higher than that of the highest dilution solution in the study by Bernardes et al 64 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 between the C 2 and S 1 sites in our work while they were calculated for H 2 and S 1 in the work by Bernardes et al. Another key difference is that the concentration of IL in the present study is approximately 10 times lower than the highest dilution of the IL investigated by Bernades et al…”

Proteins in Ionic Liquids: Current Status of Experiments and Simulations

“…However, this effect of the ions is very local since femtosecond mid-IR pump-probe spectroscopy showed that only the structure of water in direct contact with the ion is influenced [45] and the effect on further solvation shells of the ion is negligible. We showed [22] that hydrophilic anions act as mediator between the more hydrophobic imidazoliums and water, which was confirmed by other authors [21, 46–49]. If the hydrogen bonded anion-water network is very strong, cations are expelled to some extent.…”

“…1a, clusters involving several contacts of cations are quite common even for short alkyl chains [2, 14, 21]. The non-specific dispersion interaction (gray area) between the alkyl chains is in this case stronger than the Coulombic repulsion (denoted by the black arrow).…”

Evaluation of solubility and partition properties of ampicillin-based ionic liquids

“…The study of the combination of an API with an ionic liquid possessing surfactant activity is attractive because novel therapies using surfactant API-ILs can be envisaged (Bernardes et al, 2011). Accordingly, assays to determine ([P 6,6,6,14 ][Amp]).…”

“…The study of the combination of an API with an ionic liquid possessing surfactant activity is important because novel therapies using surfactant API-ILs as drug delivery devices can offer interesting avenues to be explored (Bernardes et al, 2011;Hansch and Dunn, 1972;Liu et al, 2006).…”