Showing papers on "Ionic liquid published in 2012"
TL;DR: Ionic Liquids-Based Extraction: A Promising Strategy for theAdvanced Nuclear Fuel Cycle Xiaoqi Sun, Huimin Luo, and Sheng Dai.
Abstract: Ionic Liquids-Based Extraction: A Promising Strategy for theAdvanced Nuclear Fuel Cycle Xiaoqi Sun, Huimin Luo, and Sheng Dai* Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States Energy and Transportation Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37916, United States State Key Laboratory of Rare Earth Resource Utilization, Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
719 citations
TL;DR: A critical review provides a judicious assessment of the available literature on ionic-liquid-based Aqueous Biphasic Systems and addresses two of the main applications of ionic liquid-based ABS: extraction of biomolecules and other added-value compounds, and their use as alternative approaches for removing and recovering ionic liquids from aqueous media.
Abstract: During the past decade, ionic-liquid-based Aqueous Biphasic Systems (ABS) have been the focus of a significant amount of research. Based on a compilation and analysis of the data hitherto reported, this critical review provides a judicious assessment of the available literature on the subject. We evaluate the quality of the data and establish the main drawbacks found in the literature. We discuss the main issues which govern the phase behaviour of ionic-liquid-based ABS, and we highlight future challenges to the field. In particular, the effect of the ionic liquid structure and the various types of salting-out agents (inorganic or organic salts, amino acids and carbohydrates) on the phase equilibria of ABS is discussed, as well as the influence of secondary parameters such as temperature and pH. More recent approaches using ionic liquids as additives or as replacements for common salts in polymer-based ABS are also presented and discussed to emphasize the expanding number of aqueous two-phase systems that can actually be obtained. Finally, we address two of the main applications of ionic liquid-based ABS: extraction of biomolecules and other added-value compounds, and their use as alternative approaches for removing and recovering ionic liquids from aqueous media.
704 citations
TL;DR: In this article, the authors reviewed the research progress on CO2 capture with ionic liquids with particular attention on the viewpoint of potential industrial applications, including conventional and task-specific ionic liquid, and ionic fluid-based mixtures.
Abstract: As an emerging carbon dioxide (CO2) capture technology, separating CO2 from industrial gases with ionic liquids is increasingly attracting remarkable interests. In this paper, the research progress on CO2 capture with ionic liquids is reviewed with particular attention on the viewpoint of potential industrial applications. We investigate and compare the CO2 capture capacities of pure ionic liquids, including conventional and task-specific ionic liquids, and ionic liquid-based mixtures. The mechanisms of chemisorption and physisorption are explained with experimental characteristics and molecular simulation, which show more and more important roles for screening suitable ionic liquids from tremendous candidates. Considering the scaling up of novel units for ionic liquid-based fluids, the studies on the transport properties and hydrodynamics of ionic liquid fluids are presented. The process design and assessment of ionic liquid processes are discussed, including the research progress on thermodynamic properties and prediction models. Besides giving an overview of research for each issue above, we also provide discussions for future work to try to identify the gap between the current work and the demand by real industrial applications. Finally, we present some perspectives of ionic liquid-based novel technologies, and the challenges which will be faced while developing industrially available technologies.
694 citations
TL;DR: Mesoporous nitrogen-doped carbon derived from the ionic liquid N-butyl-3-methylpyridinium dicyanamide is a highly active, cheap, and selective metal-free catalyst for the electrochemical synthesis of hydrogen peroxide that has the potential for use in a safe, sustainable, and cheap flow-reactor-based method for H( 2)O(2) production.
Abstract: Mesoporous nitrogen-doped carbon derived from the ionic liquid N-butyl-3-methylpyridinium dicyanamide is a highly active, cheap, and selective metal-free catalyst for the electrochemical synthesis of hydrogen peroxide that has the potential for use in a safe, sustainable, and cheap flow-reactor-based method for H(2)O(2) production.
560 citations
TL;DR: A review of physicochemical data of these reaction media and highlights recent advances in their use in organic synthesis and biotransformations can be found in this article, where the authors highlight the need to replace hazardous and harmful solvents with green or sustainable media.
539 citations
TL;DR: This work reviews the available literature of mixtures of ionic liquid mixtures to identify how their properties change and the possibility for their application.
Abstract: Simple ionic liquids have long been held to be designer solvents, based upon the ability to independently vary their cations and anions. The formation of mixtures of ionic liquids increases this synthetic flexibility. We review the available literature of these ionic liquid mixtures to identify how their properties change and the possibility for their application.
504 citations
TL;DR: The realization of ambipolar field-effect transistors by coupling exfoliated thin flakes of tungsten disulfide with an ionic liquid dielectric shows ideal electrical characteristics, including very steep subthreshold slopes for both electrons and holes and extremely low OFF-state currents.
Abstract: We realized ambipolar field-effect transistors by coupling exfoliated thin flakes of tungsten disulfide (WS2) with an ionic liquid dielectric. The devices show ideal electrical characteristics, including very steep subthreshold slopes for both electrons and holes and extremely low OFF-state currents. Thanks to these ideal characteristics, we determine with high precision the size of the band gap of WS2 directly from the gate-voltage dependence of the source-drain current. Our results demonstrate how a careful use of ionic liquid dielectrics offers a powerful strategy to study quantitatively the electronic properties of nanoscale materials.
498 citations
TL;DR: A catalyst made of Pd nanoparticles (NPs) supported on mesoporous N-doped carbon, Pd@CN(0132), which was shown to be highly active in promoting biomass refining, was reported.
Abstract: We report a catalyst made of Pd nanoparticles (NPs) supported on mesoporous N-doped carbon, Pd@CN0132, which was shown to be highly active in promoting biomass refining. The use of a task-specific ionic liquid (3-methyl-1-butylpyridine dicyanamide) as a precursor and silica NPs as a hard template afforded a high-nitrogen-content (12 wt %) mesoporous carbon material that showed high activity in stabilizing Pd NPs. The resulting Pd@CN0.132 catalyst showed very high catalytic activity in hydrodeoxygenation of vanillin (a typical model compound of lignin) at low H2 pressure under mild conditions in aqueous media. Excellent catalytic results (100% conversion of vanillin and 100% selectivity for 2-methoxy-4-methylphenol) were achieved, and no loss of catalytic activity was observed after six recycles.
477 citations
TL;DR: In this article, the Kamlet-Taft parameters of glycerol and poly(ethylene glycol have been resolved with new data, including the normalized Reichardt's parameter (ENT), Nile red λmax, and Kamlet's parameters (α, β, and π*) for switchable-polarity solvents.
437 citations
TL;DR: It is demonstrated here that heterogeneous catalysts of ionic liquids functionalized on superhydrophobic mesoporous polymers exhibit much higher activities in transesterification to form biodiesel than homogeneous catalytic activities of the ionic liquid themselves.
Abstract: Homogeneous catalysts usually show higher catalytic activities than heterogeneous catalysts because of their high dispersion of catalytically active sites. We demonstrate here that heterogeneous catalysts of ionic liquids functionalized on superhydrophobic mesoporous polymers exhibit much higher activities in transesterification to form biodiesel than homogeneous catalysts of the ionic liquids themselves. This phenomenon is strongly related to the unique features of high enrichment and good miscibility of the superhydrophobic mesoporous polymers for the reactants. These features should allow the design and development of a wide variety of catalysts for the conversion of organic compounds.
390 citations
TL;DR: A series of room temperature ionic liquids, in which cholinium acts as the cation and amino acids as the anions, were prepared via a simple and green chemical route and characterized, and dissolved lignin efficiently and selectively.
TL;DR: This critical review analyses most of the surface tension data reported between 2001 and 2010 (187 references) and concludes that ionic liquids present characteristic surface behavior and distinctive trends of their surface tension versus temperature.
Abstract: Some of the most active scientific research fronts of the past decade are centered on ionic liquids These fluids present characteristic surface behavior and distinctive trends of their surface tension versus temperature One way to explore and understand their unique nature is to study their surface properties This critical review analyses most of the surface tension data reported between 2001 and 2010 (187 references)
TL;DR: Ionic liquids are revealed as a class of liquids with unique and useful confinement properties and pertinent future directions of research are highlighted.
Abstract: Over recent years the Surface Force Apparatus (SFA) has been used to carry out model experiments revealing structural and dynamic properties of ionic liquids confined to thin films. Understanding characteristics such as confinement induced ion layering and lubrication is of primary importance to many applications of ionic liquids, from energy devices to nanoparticle dispersion. This Perspective surveys and compares SFA results from several laboratories as well as simulations and other model experiments. A coherent picture is beginning to emerge of ionic liquids as nano-structured in pores and thin films, and possessing complex dynamic properties. The article covers structure, dynamics, and colloidal forces in confined ionic liquids; ionic liquids are revealed as a class of liquids with unique and useful confinement properties and pertinent future directions of research are highlighted.
TL;DR: In this article, the properties of equimolar mixtures of glymes (triglyme) and nine different lithium salts (LiX) were investigated and compared with the reported data on common aprotic ionic liquids.
Abstract: To demonstrate a new family of ionic liquids (ILs), i.e., "solvate" ionic liquids, the properties (thermal, transport, and electrochemical properties, Lewis basicity, and ionicity) of equimolar molten mixtures of glymes (triglyme (G3) and tetraglyme (G4)) and nine different lithium salts (LiX) were investigated. By exploring the anion-dependent properties and comparing them with the reported data on common aprotic ILs, two different classes of liquid regimes, i.e., ordinary concentrated solutions and "solvate" ILs, were found in the glyme-Li salt equimolar mixtures ([Li(glyme)]X) depending on the anionic structures. The class a given [Li(glyme)]X belonged to was governed by competitive interactions between the glymes and Li cations and between the counteranions (X) and Li cations. [Li(glyme)]X with weakly Lewis basic anions can form long-lived [Li(glyme)](+) complex cations. Thus, they behaved as typical ionic liquids. The lithium "solvate" ILs based on [Li(glyme)]X have many desirable properties for lithium-conducting electrolytes, including high ionicity, a high lithium transference number, high Li cation concentration, and high oxidative stability, in addition to the common properties of ionic liquids. The concept of "solvate" ionic liquids can be utilized in an unlimited number of combinations of other metal salts and ligands, and will thus open a new field of research on ionic liquids.
TL;DR: An overview at the current status of ionic liquid-modified materials applied in solid-phase extraction, liquid and gas chromatography and capillary electrochromatography with reference to recent applications and the potential of Ionic liquids in the modification of capillary inner wall in capillary electrophoresis is demonstrated.
TL;DR: Recent results on the properties of IL/water mixtures indicate that Sufficiently hydrophilic ions yielded ILs that are miscible with water, and hydrophobic ions gave stable phase separation with water.
TL;DR: A critical analysis reveals that promising features of ionic liquids are combined with serious drawbacks that need to be addressed in order to utilize ILs for the efficient synthesis of cellulose derivatives.
Abstract: In the past decade, ionic liquids (ILs) have received enormous interest as solvents for cellulose. They have been studied intensively for fractionation and biorefining of lignocellulosic biomass, for dissolution of the polysaccharide, for preparation of cellulosic fibers, and in particular as reaction media for the homogeneous preparation of highly engineered polysaccharide derivatives. ILs show great potential for application on a commercial scale regarding recyclability, high dissolution power, and their broad structural diversity. However, a critical analysis reveals that these promising features are combined with serious drawbacks that need to be addressed in order to utilize ILs for the efficient synthesis of cellulose derivatives. This review presents a comprehensive overview about chemical modification of cellulose in ILs. Difficulties encountered thereby are discussed critically and current as well as future developments in this field of polysaccharide research are outlined.
TL;DR: In this paper, the main physicochemical aspects involved in the catalytic applications of "soluble" transition metal nanoparticles in ionic liquids are used to explain their properties, and a special view on the concepts of coordination catalysis is used to describe the properties of these nanoscale catalysts in solution as well as their scope and limitations in multiphase catalysis.
Abstract: The main “molecular” physicochemical aspects involved in the catalytic applications of “soluble” transition metal nanoparticles in ionic liquids are used to explain their properties. In particular, a special view on the concepts of coordination catalysis is used to describe the properties of these nanoscale catalysts in solution as well as their scope and limitations in multiphase catalysis.
TL;DR: In this article, the cycloaddition reactions of CO2 with various epoxides to form five-membered cyclic carbonates catalyzed by chitosan functionalized 1-ethyl-3-methyl imidazolium halides (CS-EMImX, X = Cl, Br) without additional solvent and metal co-catalyst were achieved in high yield and selectivity.
TL;DR: In this article, the authors review the process that led to the development of one of the most widely used force fields in the area of ionic liquids modeling, analyze its subsequent expansions and alternative models, and consider future routes of improvement to overcome present limitations.
Abstract: In this account, we review the process that led to the development of one of the most widely used force fields in the area of ionic liquids modeling, analyze its subsequent expansions and alternative models, and consider future routes of improvement to overcome present limitations. This includes the description and discussion of (1) the rationale behind the generic and systematic character of the Canongia Lopes & Padua (CLP (2) the families of ionic liquids that have been (and continue to be) parameterized over the years and those that are the most challenging both in theoretical and applied terms; (3) the steps that lead to a correct parameterization of each type of ion and its homologous family, with special emphasis on the correct modeling of their flexibility and charge distribution; (4) the validation processes of the CLP and finally (5) the compromises that have to be attained when choosing between generic or specific force fields, coarse-grain or atomistic models, and polarizable or non-polarizable methods. The application of the CL&P and other force fields to the study of ionic liquids using quantum- and statistical-mechanics methods has led to the discovery and analysis of the unique nature of their liquid phases, that is, the notion that ionic liquids are nano-segregated fluids with structural and dynamic heterogeneities at the nanoscopic scale. This successful contribution of theoretical chemistry to the field of ionic liquids will also serve as a guide throughout the ensuing discussion.
TL;DR: Light is shed on effects of ionic liquids chemistry on structure, stability, and activity of enzymes, which will be helpful for the researchers in various biocatalytic applications.
TL;DR: Ionic liquid-tethered nanoparticle hybrid electrolytes comprised of silica nanoparticles densely grafted with imidazolium-based ionic liquid chains are shown to retard lithium dendrite growth in rechargeable batteries with metallic lithium anodes.
Abstract: Ionic liquid-tethered nanoparticle hybrid electrolytes comprised of silica nanoparticles densely grafted with imidazolium-based ionic liquid chains are shown to retard lithium dendrite growth in rechargeable batteries with metallic lithium anodes. The electrolytes are demonstrated in full cell studies using both high-energy Li/MoS{sub 2} and high-power Li/TiO{sub 2} secondary batteries. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
TL;DR: This work aims to consolidate the various findings from previous works in electrochemical, biological and metal extraction applications of ionic liquids and their use in batteries, solar panels, fuel cells, drug deliveries and biomass pretreatments.
Abstract: Ionic liquids have recently gained popularity in the scientific community owing to their special properties and characteristics. One of the reasons why ionic liquids have been termed "green solvents" is due to their negligible vapour pressure. Their use in electrochemical, biological and metal extraction applications is discussed. Wide research has been carried out for their use in batteries, solar panels, fuel cells, drug deliveries and biomass pretreatments. This work aims to consolidate the various findings from previous works in these areas.
TL;DR: These new results clearly show that guanidinium-, unlike the imidazolium- and phosphonium-based ILs, do not follow the trend of increasing toxicity with the increase in the alkyl chain length, and the introduction of oxygenated groups on theAlkyl chains leads to a decrease of the toxicity of guanIDinium and also imidrazolium compounds.
TL;DR: In this paper, the authors discuss principles for rational design of ionic liquid-based formulations in protein chemistry and biocatalysis, and discuss case-by-case studies.
Abstract: The native state of a globular protein is essential for its biocatalytic function, but is marginally stable against unfolding. While unfolding equilibria are often reversible, folding intermediates and misfolds can promote irreversible protein aggregation into amorphous precipitates or highly ordered amyloid states. Addition of ionic liquids—low-melting organic salts—offers intriguing prospects for stabilizing native proteins and their enzymatic function against these deactivating reaction channels. The huge number of cations and anions that form ionic liquids allows fine-tuning of their solvent properties, which offers robust and efficient strategies for solvent optimization. Going beyond case-by-case studies, this article aims at discussing principles for a rational design of ionic liquid-based formulations in protein chemistry and biocatalysis.
Journal Article•
TL;DR: The lithium "solvate" ILs based on [Li(glyme)]X have many desirable properties for lithium-conducting electrolytes, including high ionicity, a high lithium transference number, high Li cation concentration, and high oxidative stability, in addition to the common properties of ionic liquids.
Abstract: To demonstrate a new family of ionic liquids (ILs), i.e., “solvate” ionic liquids, the properties (thermal, transport, and electrochemical properties, Lewis basicity, and ionicity) of equimolar molten mixtures of glymes (triglyme (G3) and tetraglyme (G4)) and nine different lithium salts (LiX) were investigated. By exploring the anion-dependent properties and comparing them with the reported data on common aprotic ILs, two different classes of liquid regimes, i.e., ordinary concentrated solutions and “solvate” ILs, were found in the glyme–Li salt equimolar mixtures ([Li(glyme)]X) depending on the anionic structures. The class a given [Li(glyme)]X belonged to was governed by competitive interactions between the glymes and Li cations and between the counteranions (X) and Li cations. [Li(glyme)]X with weakly Lewis basic anions can form long-lived [Li(glyme)]⁺ complex cations. Thus, they behaved as typical ionic liquids. The lithium “solvate” ILs based on [Li(glyme)]X have many desirable properties for lithium-conducting electrolytes, including high ionicity, a high lithium transference number, high Li cation concentration, and high oxidative stability, in addition to the common properties of ionic liquids. The concept of “solvate” ionic liquids can be utilized in an unlimited number of combinations of other metal salts and ligands, and will thus open a new field of research on ionic liquids.
TL;DR: In this paper, a novel fructose-based DES of choline chloride (2-hydroxyethyl-trimethylammonium) has been synthesized at different molar ratios.
TL;DR: The ability of the mixtures to dissolve cellulose was best explained by the difference β-α (net basicity), rather than β alone, which was found to change most drastically, with an almost linear decrease upon addition of water.
TL;DR: In this article, the authors reported phosphonium-based ILs (PP-ILs) that are fully miscible with both mineral oil-based and synthetic lubricants.