Mesoscopic structural and dynamic organization in ionic liquids

Russina, Olga; Schröer, Wolffram; Triolo, Alessandro

doi:10.1016/j.molliq.2015.08.025

Cited by 21 publications

(13 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…32,34 This mesoscopic structure was confirmed by systematic studies using small-angle X-ray (SAXS) and neutron scattering (SANS) on a series of [C n C 1 im] + based ILs with Cl − , [BF 4 ] − , [PF 6 ] − , and [NTf 2 ] − anions. 8,11,12,14,16,20,21,24,35 This allows correlating the dimensions of the structural inhomogeneities with the cation's alkyl chain length. Analysis of the prepeak positions q 0 showed that the lengths of the alkyl chains govern the periodicities 2π/ q 0 of the underlying structures.…”

Section: Introductionmentioning

confidence: 99%

Mesoscopic Correlation Functions in Heterogeneous Ionic Liquids

Weiss

Mars

et al. 2017

J. Phys. Chem. B

View full text Add to dashboard Cite

A common feature of ionic liquids composed of cations with long aliphatic side chains is structural heterogeneities on the nanometer length scale. This so-called microphase separation arises from the clustering of aliphatic moieties. The temperature dependence of the liquid bulk structure was studied by small-angle X-ray and neutron scattering for a set of methylimidazolium ([CCim], [CCim]) based ionic liquids with tris(pentafluoroethyl)trifluorophosphate ([FAP]), bis(trifluoromethylsulfonyl)imide ([NTf]), and bis(nonafluorobutylsulfonyl)imide ([NNf]) anions. The experimental data is quantitatively analyzed using a generalized Teubner-Strey model. Discussion of the resulting periodicity d and correlation length ξ shows that the structural heterogeneities are governed by the interplay between the alkyl chain length, the geometry of the anion, and entropic effects. Connections between the mesoscopic correlation functions, density, and entropy of fusion are discussed in comparison to alcohols. The observed dependencies allow predictions on the mesoscopic correlation functions based on macroscopic bulk quantities.

show abstract

Section: Introductionmentioning

confidence: 99%

Mesoscopic Correlation Functions in Heterogeneous Ionic Liquids

Weiss

Mars

et al. 2017

J. Phys. Chem. B

View full text Add to dashboard Cite

show abstract

“…Such techniques have been applied to mixtures of ILs with molecular solvents, neutral solutes and inorganic salts 49 as well as mixtures of ILs 50 with different cation chain lengths 51 and anions, 52,53 however we are not aware of any similar studies on IL mixtures of the complexity of those studied here.…”

Section: Discussionmentioning

confidence: 99%

Exploring the Use of Ionic Liquid Mixtures to Enhance the Performance of Dicationic Ionic Liquids

Lall-Ramnarine

Suarez

Fernandez

et al. 2017

J. Electrochem. Soc.

View full text Add to dashboard Cite

Dicationic ionic liquids (DILs) of diverse structural architectures (including symmetrical and asymmetrical ammonium, phosphonium and heterodications and the bis(trifluoromethylsulfonyl)amide (NTf 2 − ) anion) have been prepared and used as additives to N-methyl-N-ethoxyethylpyrrolidinium (P 1 EOE) NTf 2 , a relatively high-performing IL in terms of its transport properties (viscosity 53 mPa s). The three-ion, binary IL mixtures were characterized for their thermal and transport properties using differential scanning calorimetry, temperature dependent viscosity, conductivity and Pulsed Gradient Spin Echo (PGSE) NMR. Variable temperature 1 H, 19 F and 31 P self-diffusion coefficients were determined at 25, 60 and 75 • C. The order of the diffusion coefficients was D(, and the composition of the dication had a strong effect on the degree to which diffusion of all three species is more or less coupled. IL mixtures containing about 30 mol % of the dicationic NTf 2 and 70 mol % of P 1 EOE NTf 2 resulted in a significant decrease in glass transition temperatures and viscosities compared to the pure DIL. The mixtures extended the liquid range and potential for practical applications significantly. The data obtained here provides insight into the future design of dicationic salts tailored to exhibit lower viscosity and higher conductivities.

show abstract

“…However, for x IL < 0.6, the viscosity changes by roughly an order of magnitude and ∆ log(η) shows a significantly non-linear dependence on x IL . It is important to take note of this non-linearity because this response is indicative of more substantial changes occurring in dilute EAN solution [20,48,49]. The EAN/MeOH mixture in the low EAN concentration region is more strongly dominated by hydrogen bonding between MeOH and the EAN ions and the details from x-ray and neutron scattering provide ample evidence for this observation [49].…”

Section: Bulk Properties-viscositymentioning

confidence: 99%

Coumarin 153 Dynamics in Ethylammonium Nitrate: The Effects of Dilution with Methanol

Heitz

Sabo

Robillard

2021

Sustainable Chemistry

View full text Add to dashboard Cite

Magic angle intensity decay and dynamic fluorescence anisotropy measurements were made on the binary solvent system composed of ethylammonium nitrate ([N2,0,0,0+][NO3−], EAN) + methanol (MeOH) across the complete EAN mole fraction range (xIL = 0–1) using the neutral dipolar solute coumarin 153 (C153) at 295 K. Stokes–Einstein–Debye (SED) hydrodynamic theory was used as a model framework to assess the C153 rotational reorientation dynamics. Departure from stick SED prediction was observed (in contrast to literature reports that used cationic or anionic dyes) and indicated a significant influence of domain nanoheterogeneity on probe dynamics. Steady-state spectroscopy indicated minimal changes in spectral peak and width with mole fraction, except at xIL = 0.3 where absorption widths decreased by ~170 cm−1, signaling that C153 sensed a change in solution heterogeneity. Magic angle intensity decays corroborated the steady-state observation and the excited-state lifetimes showed a marked change from xIL = 0.2–0.4 where EAN-EAN interactions became notably more significant. C153 average rotation times (⟨τrot⟩) showed significant solvent decoupling with increased EAN. The rotational data were fit to a power law dependence, ⟨τrot⟩ ∝ (ηT)p, where p = 0.82, demonstrating the presence of dynamic heterogeneity in the EAN/MeOH solutions. With increased EAN, rotation times showed that the heterogeneity became increasingly more significant since the rotation times systematically decreased away from the hydrodynamic stick limit.

show abstract

Mesoscopic structural and dynamic organization in ionic liquids

Cited by 21 publications

References 63 publications

Mesoscopic Correlation Functions in Heterogeneous Ionic Liquids

Mesoscopic Correlation Functions in Heterogeneous Ionic Liquids

Exploring the Use of Ionic Liquid Mixtures to Enhance the Performance of Dicationic Ionic Liquids

Coumarin 153 Dynamics in Ethylammonium Nitrate: The Effects of Dilution with Methanol

Contact Info

Product

Resources

About