Structural Properties of [N1888][TFSI] Ionic Liquid: A Small Angle Neutron Scattering and Polarizable Molecular Dynamics Study.

In this study, we investigate the quaternary ammonium-based ionic liquid (QAIL), methyltrioctylammonium bis(trifluoromethylsulfonyl)imide, [N][TFSI], utilizing small angle neutron scattering (SANS) measurements and polarizable molecular dynamics (MD) simulations to characterize the short- and long-range liquid structure. Scattering structure factors show signatures of three length scales in reciprocal space indicative of alternating polarity ( ∼ 0.44 Å), charge ( ∼ 0.

Understanding the Electrode-Electrolyte Interfaces of Ionic Liquids and Deep Eutectic Solvents.

Developing unconventional electrolytes such as ionic liquids (ILs) and deep eutectic solvents (DESs) has led to remarkable advances in electrochemical energy storage and conversion devices. However, the understanding of the electrode-electrolyte interfaces of these electrolytes, specifically the liquid structure and the charge/electron transfer mechanism and rates, is lacking due to the complexity of molecular interactions, the difficulty in studying the buried interfaces with nanometer-scale resolution, and the distribution of the time scales for the various interfacial events. This Feature Article outlines the standing questions in the field, summarizes some of the exciting approaches and results, and discusses our contributions to probing the electrified interfaces by electrochemical impedance spectroscopy (EIS), surface-enhanced Raman spectroscopy (SERS), and neutron reflectivity (NR).

Solvation Structure, Dynamics, and Charge Transfer Kinetics of Cu and Cu in Choline Chloride Ethylene Glycol Electrolytes.

Experimental measurements and classical molecular dynamics (MD) simulations were carried out to study electrolytes containing CuCl and CuCl salts in mixtures of choline chloride (ChCl) and ethylene glycol (EG). The study focused on the concentration of 100 mM of both CuCl and CuCl with the ratio of ChCl/EG varied from 1:2, 1:3, 1:4, to 1:5. It was found that the Cu and Cu have different solvation environments in their first solvation shell.

From Salt in Solution to Solely Ions: Solvation of Methyl Viologen in Deep Eutectic Solvents and Ionic Liquids.

Solvation and transport properties of methly viologen dichloride (MVCl) in 1:2, 1:4, and 1:6 molar mixtures of choline chloride (ChCl) and ethylene glycol (EG), including the deep eutectic solvent (DES) ethaline (1:2 mixture), were studied through the application of the hole theory to measured physical properties, cyclic voltammetry, and Raman spectroscopy. The ChCl:EG mixtures were compared to the ionic liquid (IL) 1-methyl-1-propylpyrrolidinium bis(trifluoromethylsulfonyl) imide ([PYR][TFSI]) and choline bis(trifluoromethylsulfonyl)imide (ChTFSI) EG mixtures with the same molar ratios in order to understand the impact of the anion and hydrogen bond donor on solvation. Exchanging the chloride anion with TFSI is found to increase the fluidity of the solvent and promote stronger solute-solvent interactions.

CO₂-responsive microemulsions based on reactive ionic liquids.

We demonstrate that the nanodomains within a ternary system consisting of oil, surfactant, and a new reactive ionic liquid can be tuned reversibly upon exposure to and removal of CO2 under mild conditions of temperature and pressure. The equilibrium microstructures of these domains have been characterized by small-angle neutron scattering and demonstrate that control over emulsion morphology (and therefore physicochemical properties such as viscosity) and the breaking of emulsions can be achieved without the need for irreversible changes in system composition or significant energy input.

Reaction kinetics of CO2 absorption in to phosphonium based anion-functionalized ionic liquids.

The reaction kinetics between CO2 and trihexyl(tetradecyl)phosphonium ([P66614])-based ionic liquids (ILs) with prolinate ([Pro]), 2-cyanopyrrolide ([2-CNpyr]), and 3-(trifluoromethyl)pyrazolide ([3-CF3pyra]) anions are studied at temperatures from 22-60 °C. The absorption of CO2 is carried out in a stirred reactor under pseudo first order conditions. ILs are diluted to concentrations of 0.

Effect of water and temperature on absorption of CO2 by amine-functionalized anion-tethered ionic liquids.

Amine-functionalized anion-tethered ionic liquids (ILs) trihexyl(tetradecyl)phosphonium asparaginate [P(66614)][Asn], glutaminate [P(66614)][Gln], lysinate [P(66614)][Lys], methioninate [P(66614)][Met], prolinate [P(66614)][Pro], taurinate [P(66614)][Tau], and threoninate [P(66614)][Thr] were synthesized and investigated as potential absorbents for CO(2) capture from postcombustion flue gas. Their physical properties, including density, viscosity, glass transition temperature, and thermal decomposition temperature were determined. Furthermore, the CO(2) absorption isotherms of [P(66614)][Lys], [P(66614)][Tau], [P(66614)][Pro], and [P(66614)][Met] were measured using a volumetric method, and the results were modeled with two different Langmuir-type absorption models.

Equimolar CO(2) absorption by anion-functionalized ionic liquids.

Amino acid ionic liquid trihexyl(tetradecyl)phosphonium methioninate [P(66614)][Met] and prolinate [P(66614)][Pro] absorb CO(2) in nearly 1:1 stoichiometry, surpassing by up to a factor of 2 the CO(2) capture efficiency of previously reported ionic liquid and aqueous amine absorbants for CO(2). Room temperature isotherms are obtained by barometric measurements in an accurately calibrated stirred cell, and the product identity is confirmed using in situ IR. Density functional theory (DFT) calculations support the 1:1 reaction stoichiometry and predict reaction enthalpies in good agreement with calorimetric measurements and isotherms.