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Sample records for temperature ionic liquid

  1. Polarization versus Temperature in Pyridinium Ionic Liquids

    DEFF Research Database (Denmark)

    Chaban, V. V.; Prezhdo, O. V.

    2014-01-01

    Electronic polarization and charge transfer effects play a crucial role in thermodynamic, structural, and transport properties of room-temperature ionic liquids (RTILs). These nonadditive interactions constitute a useful tool for tuning physical chemical behavior of RTILs. Polarization and charge...... interactions changes negligibly between 300 and 900 K, while the average dipole moment increases due to thermal fluctuations of geometries. Our results contribute to the fundamental understanding of electronic effects in the condensed phase of ionic systems and foster progress in physical chemistry...

  2. Extraction of organic compounds with room temperature ionic liquids.

    Science.gov (United States)

    Poole, Colin F; Poole, Salwa K

    2010-04-16

    Room temperature ionic liquids are novel solvents with a rather specific blend of physical and solution properties that makes them of interest for applications in separation science. They are good solvents for a wide range of compounds in which they behave as polar solvents. Their physical properties of note that distinguish them from conventional organic solvents are a negligible vapor pressure, high thermal stability, and relatively high viscosity. They can form biphasic systems with water or low polarity organic solvents and gases suitable for use in liquid-liquid and gas-liquid partition systems. An analysis of partition coefficients for varied compounds in these systems allows characterization of solvent selectivity using the solvation parameter model, which together with spectroscopic studies of solvent effects on probe substances, results in a detailed picture of solvent behavior. These studies indicate that the solution properties of ionic liquids are similar to those of polar organic solvents. Practical applications of ionic liquids in sample preparation include extractive distillation, aqueous biphasic systems, liquid-liquid extraction, liquid-phase microextraction, supported liquid membrane extraction, matrix solvents for headspace analysis, and micellar extraction. The specific advantages and limitations of ionic liquids in these studies is discussed with a view to defining future uses and the need not to neglect the identification of new room temperature ionic liquids with physical and solution properties tailored to the needs of specific sample preparation techniques. The defining feature of the special nature of ionic liquids is not their solution or physical properties viewed separately but their unique combinations when taken together compared with traditional organic solvents. Copyright 2009 Elsevier B.V. All rights reserved.

  3. Synthesis of 1-alkyl triazolium triflate room temperature ionic liquids ...

    Indian Academy of Sciences (India)

    Sci. Vol. 127, No. 9, September 2015, pp. 1539–1545. c Indian Academy of Sciences. DOI 10.1007/s12039-015-0919-6. Synthesis of 1-alkyl triazolium triflate room temperature ionic liquids and their catalytic studies in multi-component Biginelli reaction. SANKARANARAYANAN NAGARAJAN, TANVEER M SHAIKH and.

  4. Room-Temperature Ionic Liquids for Electrochemical Capacitors

    Science.gov (United States)

    Fireman, Heather; Yowell, Leonard; Moloney, Padraig G.; Arepalli, Sivaram; Nikolaev, P.; Huffman, C.; Ready, Jud; Higgins, C.D.; Turano, S. P.; Kohl, P.A.; hide

    2009-01-01

    A document discusses room-temperature ionic liquids (RTILs) used as electrolytes in carbon-nanotube-based, electrochemical, double-layer capacitors. Unlike the previous electrolyte (EtNB4 in acetonitrile), the RTIL used here does not produce cyanide upon thermal decomposition and does not have a moisture sensitivity.

  5. Ionic liquid electrolyte for supercapacitor with high temperature compatibility

    Science.gov (United States)

    Haque, Mazharul; Li, Qi; Kuzmenko, Volodymyr; Smith, Anderson D.; Enoksson, Peter

    2017-11-01

    This work describes the electrochemical investigation of two ionic liquids (ILs), 1-ethyl-3-methylimidazolium acetate (EMIM Ac) and 1-butyl-3-methylimidazolium chloride (BMIM Cl), as electrolytes in supercapacitors (SC). A comprehensive study on high temperature (HT) endurance that is required for system integration in microelectronics has also been carried out. It has been found that EMIM Ac containing SC performs better than a BMIM Cl containing SC, and HT treatment improves the capacitive performance.

  6. Self-segregated nanostructure in room temperature ionic liquids.

    Science.gov (United States)

    Pontoni, Diego; Haddad, Julia; Di Michiel, Marco; Deutsch, Moshe

    2017-10-04

    The nanosegregated bulk structure, and its evolution with the cation's alkyl length n, are studied by X-ray scattering for an unprecedentedly broad homologous series of a model room-temperature ionic liquid, [CnMIM][NTf2] (n = 4-22). A tri-periodic local structure is found, with the lateral periodicities, dII and dIII independent of n, and a longitudinal one, dI, linearly increasing with n. The results are consistent with a local structure comprising alternating layers of polar headgroups and apolar, interdigitated, partly overlapping, cations' alkyl tails, of an average macroscopic mass density close to that of liquid alkanes. A slope decrease in the linear dI(n) suggests a change from a lower to a higher rate of increase with n of chain overlap for n ≥ 12. The order decay lengths of the layering, and of the lateral chain packing, increase with n, as expected from the increasing van der Waals interaction's domination of the structure. The headgroups' lateral packing decay length decreases with n, due to increasing frustration between the longer lateral periodicity preferred by the headgroups, and the shorter lateral periodicity preferred by the chains. A comparison of the bulk and surface structures highlights the surface's ordering effect, which, however, does not induce here a surface phase different from the bulk, as it does in liquid crystals and liquid alkanes.

  7. Liquid-liquid miscibility and volumetric properties of aqueous solutions of ionic liquids as a function of temperature

    OpenAIRE

    Wang, Silu; Jacquemin, Johan; Husson, Pascale; Hardacre, Christpher; Costa Gomes, Margarita F.

    2009-01-01

    The volumetric properties of seven {water + ionic liquid} binary mixtures have been studied as a function of temperature from (293 to 343) K. The phase behaviour of the systems was first investigated using a nephelometric method and excess molar volumes were calculated from densities measured using an Anton Paar densimeter and fitted using a Redlich-Kister type equation. Two ionic liquids fully miscible with water (1-butyl-3-methylimidazolium tetrafluoroborate ([CCIm][BF]) and 1-ethyl-3-methy...

  8. Are Room-Temperature Ionic Liquids Dilute Electrolytes?

    Science.gov (United States)

    Lee, Alpha A; Vella, Dominic; Perkin, Susan; Goriely, Alain

    2015-01-02

    An important question in understanding the structure of ionic liquids is whether ions are truly "free" and mobile, which would correspond to a concentrated ionic melt, or are rather "bound" in ion pairs, that is, a liquid of ion pairs with a small concentration of free ions. Recent surface force balance experiments from different groups have given conflicting answers to this question. We propose a simple model for the thermodynamics and kinetics of ion pairing in ionic liquids. Our model takes into account screened ion-ion, dipole-dipole, and dipole-ion interactions in the mean-field limit. The results of this model suggest that almost two-thirds of the ions are free at any instant, and ion pairs have a short lifetime comparable to the characteristic time scale for diffusion. These results suggest that there is no particular thermodynamic or kinetic preference for ions to reside in pairs. We therefore conclude that ionic liquids are concentrated, rather than dilute, electrolytes.

  9. Synthesis and characterization of ionic polymer networks in a room-temperature ionic liquid.

    Science.gov (United States)

    Stanzione, Joseph F; Jensen, Robert E; Costanzo, Philip J; Palmese, Giuseppe R

    2012-11-01

    Ionic liquid gels (ILGs) for potential use in ion transport and separation applications were generated via a free radical copolymerization of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) and N,N'-methylene(bis)acrylamide (MBA) using 1-ethyl-3-methylimidazolium ethylsulfate (IL) as a room temperature ionic liquid solvent medium. The AMPS and MBA monomer solubility window in the IL in the temperature range of 25 to 65 °C was determined. In situ ATR-FTIR showed near complete conversion of monomers to a cross-linked polymer network. ILGs with glass transition temperatures (T(g)s) near -50 °C were generated with T(g) decreasing with increasing IL content. The elastic moduli in compression (200 to 6600 kPa) decreased with increasing IL content and increasing AMPS content while the conductivities (0.35 to 2.14 mS cm⁻¹) increased with increasing IL content and decreasing MBA content. The polymer-IL interaction parameter (χ) (0.48 to 0.55) was determined via a modified version of the Bray and Merrill equation.

  10. Structural investigation of room-temperature ionic liquids and high-temperature ionic melts using triplet correlation functions

    Science.gov (United States)

    Dhabal, Debdas; Gupta, Aditya; Kashyap, Hemant K.

    2017-03-01

    We use means of molecular dynamics simulation to understand the local structural arrangements in three trihexyltetradecylphosphonium (P6,6,6 ,14 +) based room-temperature ionic liquids (RTILs) by using triplet correlation functions (TCFs) along with pair correlation functions (PCFs) and X-ray scattering structure functions (S(q)s). The anions in these RTILs are either spherically symmetric but with different effective sizes (bromide (Br-) and tetrafluoroborate (BF4-)) or angular such as dicyanamide (DCA-). The simulated PCFs, S(q)s, and TCFs of the three RTILs have been compared with three high-temperature ionic melts (HTIMs); NaBr, NaCl, and NaF. In general, the pair correlation function gives angle-averaged probability as a function of inter-particle distance whereas the TCFs associated with equilateral and isosceles triangle configurations can be used to delineate angle-resolved information of liquids structure within nearest solvation shells. For the three ionic liquids studied, a very careful examination of co-ionic and counter-ionic TCFs associated with the equilateral triangular configuration within the nearest solvation shells of the ions reveals that co-ions (cat-cat-cat and an-an-an) favor close-packed local arrangement, but with lower probability for the DCA- RTIL. Co-ionic and counter-ionic TCFs obtained for HTIMs are found to be similar to that of RTILs with spherical anions. The TCFs associated with the isosceles triangle configuration signify that the ionic liquid with Br- anions tends to exhibit larger anion-cation-anion angle than that in the other two RTILs. Moreover, diffused counter-ionic angular correlations are observed in the DCA- system. We also observed angle-dependent charge ordering in all the three RTILs although its extent is enhanced for RTILs with spherical anions, very similar to what we find for NaBr, NaCl, and NaF melts. This study suggests that the presence of charge ordering is a generic feature of both the RTILs and HTIMs.

  11. Proactive aquatic ecotoxicological assessment of room-temperature ionic liquids

    Science.gov (United States)

    Kulacki, K.J.; Chaloner, D.T.; Larson, J.H.; Costello, D.M.; Evans-White, M. A.; Docherty, K.M.; Bernot, R.J.; Brueseke, M.A.; Kulpa, C.F.; Lamberti, G.A.

    2011-01-01

    Aquatic environments are being contaminated with a myriad of anthropogenic chemicals, a problem likely to continue due to both unintentional and intentional releases. To protect valuable natural resources, novel chemicals should be shown to be environmentally safe prior to use and potential release into the environment. Such proactive assessment is currently being applied to room-temperature ionic liquids (ILs). Because most ILs are water-soluble, their effects are likely to manifest in aquatic ecosystems. Information on the impacts of ILs on numerous aquatic organisms, focused primarily on acute LC50 and EC50 endpoints, is now available, and trends in toxicity are emerging. Cation structure tends to influence IL toxicity more so than anion structure, and within a cation class, the length of alkyl chain substituents is positively correlated with toxicity. While the effects of ILs on several aquatic organisms have been studied, the challenge for aquatic toxicology is now to predict the effects of ILs in complex natural environments that often include diverse mixtures of organisms, abiotic conditions, and additional stressors. To make robust predictions about ILs will require coupling of ecologically realistic laboratory and field experiments with standard toxicity bioassays and models. Such assessments would likely discourage the development of especially toxic ILs while shifting focus to those that are more environmentally benign. Understanding the broader ecological effects of emerging chemicals, incorporating that information into predictive models, and conveying the conclusions to those who develop, regulate, and use those chemicals, should help avoid future environmental degradation. ?? 2011 Bentham Science Publishers Ltd.

  12. Shifts in the temperature of maximum density (TMD) of ionic liquid aqueous solutions.

    Science.gov (United States)

    Tariq, M; Esperança, J M S S; Soromenho, M R C; Rebelo, L P N; Lopes, J N Canongia

    2013-07-14

    This work investigates for the first time shifts in the temperature of maximum density (TMD) of water caused by ionic liquid solutes. A vast amount of high-precision volumetric data--more than 6000 equilibrated (static) high-precision density determination corresponding to ∼90 distinct ionic liquid aqueous solutions of 28 different types of ionic liquid--allowed us to analyze the TMD shifts for different homologous series or similar sets of ionic solutes and explain the overall effects in terms of hydrophobic, electrostatic and hydrogen-bonding contributions. The differences between the observed TMD shifts in the -2 liquids and are consistent with previous results that established hydrophobic and hydrophilic scales for ionic liquid ions based on their specific interactions with water and other probe molecules.

  13. Moisture Stable Ambient Temperature Ionic Liquids: Solvents for the New Millennium. 1. The Heck Reaction

    Directory of Open Access Journals (Sweden)

    Andrea Dallas

    2000-06-01

    Full Text Available In this paper we report examples of the Heck reaction in the new moisture stable ambient temperature ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]PF6. We have found that the yield of product is comparable with Heck reactions carried out in DMF, the conventional solvent for this reaction, and that the ionic liquid/catalyst mixture can be recycled several times.

  14. Ruthenium(III Chloride Catalyzed Acylation of Alcohols, Phenols, and Thiols in Room Temperature Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Mingzhong Cai

    2009-09-01

    Full Text Available Ruthenium(III chloride-catalyzed acylation of a variety of alcohols, phenols, and thiols was achieved in high yields under mild conditions (room temperature in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]. The ionic liquid and ruthenium catalyst can be recycled at least 10 times. Our system not only solves the basic problem of ruthenium catalyst reuse, but also avoids the use of volatile acetonitrile as solvent.

  15. Extraction of aromatic compounds using ionic liquids and low transition temperature mixtures as separation agents

    OpenAIRE

    Fernandez Requejo, Patricia

    2015-01-01

    The main objective of this thesis is the evaluation of the feasibility of two types of designer solvents, ionic liquids (ILs) and low transition temperature mixtures (LTTMs), as extraction agents to improve the efficiency and/or sustainability of the separation of aromatic hydrocarbons from their mixtures with aliphatic hydrocarbons. The research about the applicability of the ionic liquids as entrainers for the separation of aromatic/aliphatic mixtures was developed through the experimental ...

  16. Ionic liquids and ionic liquid acids with high temperature stability for fuel cell and other high temperature applications, method of making and cell employing same

    Science.gov (United States)

    Angell, C Austen [Mesa, AZ; Xu, Wu [Broadview Heights, OH; Belieres, Jean-Philippe [Chandler, AZ; Yoshizawa, Masahiro [Tokyo, JP

    2011-01-11

    Disclosed are developments in high temperature fuel cells including ionic liquids with high temperature stability and the storage of inorganic acids as di-anion salts of low volatility. The formation of ionically conducting liquids of this type having conductivities of unprecedented magnitude for non-aqueous systems is described. The stability of the di-anion configuration is shown to play a role in the high performance of the non-corrosive proton-transfer ionic liquids as high temperature fuel cell electrolytes. Performance of simple H.sub.2(g) electrolyte/O.sub.2(g) fuel cells with the new electrolytes is described. Superior performance both at ambient temperature and temperatures up to and above 200.degree. C. are achieved. Both neutral proton transfer salts and the acid salts with HSO.sup.-.sub.4 anions, give good results, the bisulphate case being particularly good at low temperatures and very high temperatures. The performance of all electrolytes is improved by the addition of a small amount of involatile base of pK.sub.a value intermediate between those of the acid and base that make the bulk electrolyte. The preferred case is the imidazole-doped ethylammonium hydrogensulfate which yields behavior superior in all respects to that of the industry standard phosphoric acid electrolyte.

  17. Ionic liquids in tribology.

    Science.gov (United States)

    Minami, Ichiro

    2009-06-24

    Current research on room-temperature ionic liquids as lubricants is described. Ionic liquids possess excellent properties such as non-volatility, non-flammability, and thermo-oxidative stability. The potential use of ionic liquids as lubricants was first proposed in 2001 and approximately 70 articles pertaining to fundamental research on ionic liquids have been published through May 2009. A large majority of the cations examined in this area are derived from 1,3-dialkylimidazolium, with a higher alkyl group on the imidazolium cation being beneficial for good lubrication, while it reduces the thermo-oxidative stability. Hydrophobic anions provide both good lubricity and significant thermo-oxidative stability. The anions decompose through a tribochemical reaction to generate metal fluoride on the rubbed surface. Additive technology to improve lubricity is also explained. An introduction to tribology as an interdisciplinary field of lubrication is also provided.

  18. Effect of room temperature ionic liquid structure on the enzymatic acylation of flavonoids

    DEFF Research Database (Denmark)

    Lue, Bena-Marie; Guo, Zheng; Xu, Xuebing

    2010-01-01

    Enzymatic acylation reactions of flavonoids (rutin, esculin) with long chain fatty acids (palmitic, oleic acids) were carried out in 14 different ionic liquid media containing a range of cation and anion structures. Classification of RTILs according to flavonoid solubility (using COSMO...... must be struck that maximized flavonoid solubility with minimum negative impact on lipase activity. The process also benefitted from an increased reaction temperature which may have helped to reduced mass transfer limitations. Keywords: Room temperature ionic liquids (RTILs); Biosynthesis; Acylation......; Flavonoids; Lipase; Long chain fatty acids...

  19. Probing Ionic Liquid Aqueous Solutions Using Temperature of Maximum Density Isotope Effects

    Directory of Open Access Journals (Sweden)

    Mohammad Tariq

    2013-03-01

    Full Text Available This work is a new development of an extensive research program that is investigating for the first time shifts in the temperature of maximum density (TMD of aqueous solutions caused by ionic liquid solutes. In the present case we have compared the shifts caused by three ionic liquid solutes with a common cation—1-ethyl-3-methylimidazolium coupled with acetate, ethylsulfate and tetracyanoborate anions—in normal and deuterated water solutions. The observed differences are discussed in terms of the nature of the corresponding anion-water interactions.

  20. Quantitative structure—property relationship for thermal decomposition temperature of ionic liquids

    DEFF Research Database (Denmark)

    Gharagheizi, Farhad; Sattari, Mehdi; Ilani-Kashkouli, Poorandokht

    2012-01-01

    In this study, a wide literature survey has been conducted to gather an extensive set of thermal decomposition temperature (Td) data for ionic liquids (ILs). A data set consisting of Td data for 586 ILs was collated from 71 different literature sources. Using this data set, a reliable quantitative...

  1. How do polymerized room-temperature ionic liquid membranes plasticize during high pressure CO2 permeation?

    NARCIS (Netherlands)

    Simons-Fischbein, K.; Nijmeijer, Dorothea C.; Bara, J.B.; Noble, R.D.; Wessling, Matthias

    2010-01-01

    Room-temperature ionic liquids (RTILs) are a class of organic solvents that have been explored as novel media for CO2 separations. Polymerized RTILs (poly(RTILs)) can be synthesized from RTIL monomers to form dense, solid gas selective membranes. It is of interest to understand the permeation

  2. Graphene-ionic liquid composites

    Energy Technology Data Exchange (ETDEWEB)

    Aksay, Ilhan A.; Korkut, Sibel; Pope, Michael; Punckt, Christian

    2016-11-01

    Method of making a graphene-ionic liquid composite. The composite can be used to make elec-trodes for energy storage devices, such as batteries and supercapacitors. Dis-closed and claimed herein is method of making a graphene-ionic liquid com-posite, comprising combining a graphene source with at least one ionic liquid and heating the combination at a temperature of at least about 130 .degree. C.

  3. Application of room-temperature ionic liquids in preparation of highly porous polymer membranes and microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Hoi [Dept. of Chemistry, Dankook University, Cheonan (Korea, Republic of); Seo, Jae Won; Shin, Ueon Sang [Dept. of Nanobiomedical Science and BK21 PlUS NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan (Korea, Republic of)

    2015-02-15

    Polylactic acid (PLA) and polycaprolactone (PCL) devices with diverse morphologies, such as particulate structure, porous structures, and microspheres, were prepared using imidazolium- or ammonium-based room-temperature ionic liquids [bmim]X or [toma]X (X = NTf{sub 2} , PF{sub 6} , OTf, BF{sub 4} , Cl). Their morphological transformations could be induced by diverse approaches, including the changes of polymer type, the cationic or counter-anionic change of ionic liquid, the concentration change of ionic liquid, as well as the type and the quantity change of organic solvent. The results are likely to provide useful information for the production of diverse devices (or scaffolds) with particulate or porous structure and beads with various sizes and surface morphologies in fields such as biomedical tissue engineering, drug delivery, gas storage and separation, heterogeneous catalysis, and polymer gel electrolytes.

  4. An Unexpected Reaction between 5-Hydroxymethylfurfural and Imidazolium-Based Ionic Liquids at High Temperatures

    Directory of Open Access Journals (Sweden)

    Zongbao K. Zhao

    2011-10-01

    Full Text Available A new compound was detected during the production of 5-hydroxymethylfurfural (HMF from glucose and cellulose in the ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl at high temperatures. Further experiments found that it was derived from the reaction of HMF with [Bmim]Cl. The structure of new compound was established as 1-butyl-2-(5’-methyl-2’-furoylimidazole (BMI based on nuclear magnetic resonance and mass spectrometry analysis, and a possible mechanism for its formation was proposed. Reactions of HMF with other imidazolium-based ionic liquids were performed to check the formation of BMI. Our results provided new insights in terms of side reactions between HMF and imidazolium-based ionic liquids, which should be valuable for designing better processes for the production of furans using biomass and related materials.

  5. Thermotropic Ionic Liquid Crystals

    OpenAIRE

    Sabine Laschat; Axenov, Kirill V

    2011-01-01

    The last five years’ achievements in the synthesis and investigation of thermotropic ionic liquid crystals are reviewed. The present review describes the mesomorphic properties displayed by organic, as well as metal-containing ionic mesogens. In addition, a short overview on the ionic polymer and self-assembled liquid crystals is given. Potential and actual applications of ionic mesogens are also discussed.

  6. Fission-Product Separation Based on Room-Temperature Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Huimin; Hussey, Charles L.

    2005-09-30

    The objectives of this project are (a) to synthesize new ionic liquids tailored for the extractive separation of Cs + and Sr 2+; (b) to select optimum macrocyclic extractants through studies of complexation of fission products with macrocyclic extractants and transport in new extraction systems based on ionic liquids; (c) to develop efficient processes to recycle ionic liquids and crown ethers; and (d) to investigate chemical stabilities of ionic liquids under strong acid, strong base, and high-level-radiation conditions.

  7. Fission-Product Separation Based on Room-Temperature Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Huimin

    2006-11-15

    The objectives of this project are (a) to synthesize new ionic liquids tailored for the extractive separation of Cs + and Sr 2+; (b) to select optimum macrocyclic extractants through studies of complexation of fission products with macrocyclic extractants and transport in new extraction systems based on ionic liquids; (c) to develop efficient processes to recycle ionic liquids and crown ethers; and (d) to investigate chemical stabilities of ionic liquids under strong acid, strong base, and high-level-radiation conditions.

  8. Communication: Anomalous temperature dependence of the intermediate range order in phosphonium ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Hettige, Jeevapani J.; Kashyap, Hemant K.; Margulis, Claudio J., E-mail: claudio-margulis@uiowa.edu [Department of Chemistry, University of Iowa, Iowa City, Iowa 52242 (United States)

    2014-03-21

    In a recent article by the Castner and Margulis groups [Faraday Discuss. 154, 133 (2012)], we described in detail the structure of the tetradecyltrihexylphosphonium bis(trifluoromethylsulfonyl)-amide ionic liquid as a function of temperature using X-ray scattering, and theoretical partitions of the computationally derived structure function. Interestingly, and as opposed to the case in most other ionic-liquids, the first sharp diffraction peak or prepeak appears to increase in intensity as temperature is increased. This phenomenon is counter intuitive as one would expect that intermediate range order fades as temperature increases. This Communication shows that a loss of hydrophobic tail organization at higher temperatures is counterbalanced by better organization of polar components giving rise to the increase in intensity of the prepeak.

  9. Salting-out effects in aqueous ionic liquid solutions: cloud-point temperature shifts.

    Science.gov (United States)

    Trindade, Joana R; Visak, Zoran P; Blesic, Marijana; Marrucho, Isabel M; Coutinho, João A P; Lopes, José N Canongia; Rebelo, Luis P N

    2007-05-10

    The effects of the addition of three inorganic salts, namely, NaCl, Na(2)SO(4), and Na(3)PO(4), on the liquid-liquid (L-L) phase diagram of aqueous solutions containing the model ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate, [bmim][BF(4)], were investigated. All three inorganic salts trigger salting-out effects, leading to significant upward shifts of the L-L demixing temperatures of the systems. The magnitude of the shifts depends on both the water-structuring nature of the salt and its concentration; that is, the effects are correlated with the ionic strength of the solution and the Gibbs free energy of hydration of the inorganic salt. The pH effect and the occurrence of salt precipitation in concentrated solutions are also discussed.

  10. Is the boundary layer of an ionic liquid equally lubricating at higher temperature?

    Science.gov (United States)

    Hjalmarsson, Nicklas; Atkin, Rob; Rutland, Mark W

    2016-04-07

    Atomic force microscopy has been used to study the effect of temperature on normal forces and friction for the room temperature ionic liquid (IL) ethylammonium nitrate (EAN), confined between mica and a silica colloid probe at 25 °C, 50 °C, and 80 °C. Force curves revealed a strong fluid dynamic influence at room temperature, which was greatly reduced at elevated temperatures due to the reduced liquid viscosity. A fluid dynamic analysis reveals that bulk viscosity is manifested at large separation but that EAN displays a nonzero slip, indicating a region of different viscosity near the surface. At high temperatures, the reduction in fluid dynamic force reveals step-like force curves, similar to those found at room temperature using much lower scan rates. The ionic liquid boundary layer remains adsorbed to the solid surface even at high temperature, which provides a mechanism for lubrication when fluid dynamic lubrication is strongly reduced. The friction data reveals a decrease in absolute friction force with increasing temperature, which is associated with increased thermal motion and reduced viscosity of the near surface layers but, consistent with the normal force data, boundary layer lubrication was unaffected. The implications for ILs as lubricants are discussed in terms of the behaviour of this well characterised system.

  11. Volatilization and Thermal Decomposition Mechanisms of Room-Temperature Ionic Liquids (PRE-PRINT)

    Science.gov (United States)

    2017-03-07

    Date: 20 Nov 2008. 14. ABSTRACT Recent interest in room temperature ionic liquids (RTILs) was based initially on the replacement of volatile...indicated that volatilization of these species occurs as a single ion pair. Recent ALS studies on the photoionization of other 1- alkyl-3...methylimidazolium based RTILs, show these systems can be more complex, with possible dissociative photoionization occurring at even the lowest detectable reservoir

  12. Ion transport and structural dynamics in homologous ammonium and phosphonium-based room temperature ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Philip J., E-mail: pgrif@seas.upenn.edu [Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Holt, Adam P. [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States); Tsunashima, Katsuhiko [Department of Materials Science, National Institute of Technology, Wakayama College, 77 Noshima, Nada-cho, Gobo, Wakayama 644-0023 (Japan); Sangoro, Joshua R. [Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Kremer, Friedrich [Institute of Experimental Physics I, University of Leipzig, Linnestr. 5, 04103 Leipzig (Germany); Sokolov, Alexei P. [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States); Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996 (United States); Chemical Sciences Division, Oak Ridge National Lab, Oak Ridge, Tennessee 37830 (United States)

    2015-02-28

    Charge transport and structural dynamics in a homologous pair of ammonium and phosphonium based room temperature ionic liquids (ILs) have been characterized over a wide temperature range using broadband dielectric spectroscopy and quasi-elastic light scattering spectroscopy. We have found that the ionic conductivity of the phosphonium based IL is significantly enhanced relative to the ammonium homolog, and this increase is primarily a result of a lower glass transition temperature and higher ion mobility. Additionally, these ILs exhibit pronounced secondary relaxations which are strongly influenced by the atomic identity of the cation charge center. While the secondary relaxation in the phosphonium IL has the expected Arrhenius temperature dependence characteristic of local beta relaxations, the corresponding relaxation process in the ammonium IL was found to exhibit a mildly non-Arrhenius temperature dependence in the measured temperature range—indicative of molecular cooperativity. These differences in both local and long-range molecular dynamics are a direct reflection of the subtly different inter-ionic interactions and mesoscale structures found in these homologous ILs.

  13. Determination of water in room temperature ionic liquids by cathodic stripping voltammetry at a gold electrode.

    Science.gov (United States)

    Zhao, Chuan; Bond, Alan M; Lu, Xunyu

    2012-03-20

    An electrochemical method based on cathodic stripping voltammetry at a gold electrode has been developed for the determination of water in ionic liquids. The technique has been applied to two aprotic ionic liquids, (1-butyl-3-ethylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium hexafluorophosphate), and two protic ionic liquids, (bis(2-hydroxyethyl)ammonium acetate and triethylammonium acetate). When water is present in an ionic liquid, electrooxidation of a gold electrode forms gold oxides. Thus, application of an anodic potential scan or holding the potential of the electrode at a very positive value leads to accumulation of an oxide film. On applying a cathodic potential scan, a sensitive stripping peak is produced as a result of the reduction of gold oxide back to gold. The magnitude of the peak current generated from the stripping process is a function of the water concentration in an ionic liquid. The method requires no addition of reagents and can be used for the sensitive and in situ determination of water present in small volumes of ionic liquids. Importantly, the method allows the determination of water in the carboxylic acid-based ionic liquids, such as acetate-based protic ionic liquids, where the widely used Karl Fischer titration method suffering from an esterification side reaction which generates water as a side product.

  14. Metal-air cell comprising an electrolyte with a room temperature ionic liquid and hygroscopic additive

    Science.gov (United States)

    Friesen, Cody A.; Krishnan, Ramkumar; Tang, Toni; Wolfe, Derek

    2014-08-19

    An electrochemical cell comprising an electrolyte comprising water and a hydrophobic ionic liquid comprising positive ions and negative ions. The electrochemical cell also includes an air electrode configured to absorb and reduce oxygen. A hydrophilic or hygroscopic additive modulates the hydrophobicity of the ionic liquid to maintain a concentration of the water in the electrolyte is between 0.001 mol % and 25 mol %.

  15. Room Temperature Ionic Liquids as Green Solvent Alternatives in the Metathesis of Oleochemical Feedstocks

    Directory of Open Access Journals (Sweden)

    Priya A. Thomas

    2016-02-01

    Full Text Available One of the most important areas of green chemistry is the application of environmentally friendly solvents in catalysis and synthesis. Conventional organic solvents pose a threat to the environment due to the volatility, highly flammability, toxicity and carcinogenic properties they exhibit. The recently emerged room temperature ionic liquids (RTILs are promising green solvent alternatives to the volatile organic solvents due to their ease of reuse, non-volatility, thermal stability and ability to dissolve a variety of organic and organometallic compounds. This review explores the use of RTILs as green solvent media in olefin metathesis for applications in the oleochemical industry.

  16. Molar conductivity behavior of ionic liquid compare to inorganic salt in electrolyte solution at ambien temperature

    Science.gov (United States)

    Hanibah, H.; Hashim, N. Z. Nor; Shamsudin, I. J.

    2017-09-01

    Molar Conductivity (Λ) behaviour of 1-butyl-3-methylimidazolium (Bmin) acetate and Bmin chloride (Bmin Cl) ionic liquids compared to lithium perchlorate (LiClO4) has been studied in aqueous and acetonitrile (ACN) solution at ambient temperature. The limiting molar conductivity (Λ0) was obtained using the Kohlrausch's and Ostwald's equation for the investigated systems. The results show that the Λ0 value for LiClO4 in both aqueous or acetonitrile (ACN) electrolyte system with a highest value as compare to ionic liquid electrolyte systems. This might as a result of ions association of LiClO4 in aqueous medium as the concentration of the solute increases in the solvent. In addition, the partial dissociation behaviour of LiClO4 in less polar solvent such as ACN also significantly affects the Λ0 value for this electrolyte system. However, for Bmin acetate and Bmin Cl in the aqueous or ACN medium show a much lower Λ0 value as compare to LiClO4 electrolyte system, 45.64, 74.63 and 107.32 S cm2 mol-1 respectively. This as a result of the nature behaviour of ionic liquid itself that present as free moving ions at room temperature before any dissolution into the solvent. In addition, a vice versa trend of Λ0 value is noted for Bmin acetate and Bmin Cl, 21.34 and 14.56 S cm2 mol-1 respectively in ACN electrolyte system. This indicated the solvent and the size of the anion play an important role in the estimation of limiting molar conductivity values which significantly affect the present of total free moving ions in an electrolyte system.

  17. Improved Ionic Liquids as Space Lubricants Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ionic liquids are candidate lubricant materials. However for application in low temperature space mechanisms their lubrication performance needs to be enhanced. UES...

  18. 81929 - Fission-Product Separation Based on Room - Temperature Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Robin D. Rogers

    2004-12-09

    This project has demonstrated that Sr2+ and Cs+ can be selectively extracted from aqueous solutions into ionic liquids using crown ethers and that unprecedented large distribution coefficients can be achieved for these fission products. The volume of secondary wastes can be significantly minimized with this new separation technology. Through the current EMSP funding, the solvent extraction technology based on ionic liquids has been shown to be viable and can potentially provide the most efficient separation of problematic fission products from high level wastes. The key results from the current funding period are the development of highly selective extraction process for cesium ions based on crown ethers and calixarenes, optimization of selectivities of extractants via systematic change of ionic liquids, and investigation of task-specific ionic liquids incorporating both complexant and solvent characteristics.

  19. Low-Temperature Carrier Transport in Ionic-Liquid-Gated Hydrogen-Terminated Silicon

    Science.gov (United States)

    Sasama, Yosuke; Yamaguchi, Takahide; Tanaka, Masashi; Takeya, Hiroyuki; Takano, Yoshihiko

    2017-11-01

    We fabricated ionic-liquid-gated field-effect transistors on the hydrogen-terminated (111)-oriented surface of undoped silicon. Ion implantation underneath electrodes leads to good ohmic contacts, which persist at low temperatures down to 1.4 K. The sheet resistance of the channel decreases by more than five orders of magnitude as the gate voltage is changed from 0 to -1.6 V at 220 K. This is caused by the accumulation of hole carriers. The sheet resistance shows thermally activated behavior at temperatures below 10 K, which is attributed to hopping transport of the carriers. The activation energy decreases towards zero with increasing carrier density, suggesting the approach to an insulator-metal transition. We also report the variation of device characteristics induced by repeated sweeps of the gate voltage.

  20. Heats of vaporization of room temperature ionic liquids by tunable vacuum ultraviolet photoionization

    Energy Technology Data Exchange (ETDEWEB)

    Chambreau, Steven D.; Vaghjiani, Ghanshyam L.; To, Albert; Koh, Christine; Strasser, Daniel; Kostko, Oleg; Leone, Stephen R.

    2009-11-25

    The heats of vaporization of the room temperature ionic liquids (RTILs) N-butyl-N-methylpyrrolidinium bistrifluorosulfonylimide, N-butyl-N-methylpyrrolidinium dicyanamide, and 1-butyl-3-methylimidazolium dicyanamide are determined using a heated effusive vapor source in conjunction with single photon ionization by a tunable vacuum ultraviolet synchrotron source. The relative gas phase ionic liquid vapor densities in the effusive beam are monitored by clearly distinguished dissociative photoionization processes via a time-of-flight mass spectrometer at a tunable vacuum ultraviolet beamline 9.0.2.3 (Chemical Dynamics Beamline) at the Advanced Light Source synchrotron facility. Resulting in relatively few assumptions, through the analysis of both parent cations and fragment cations, the heat of vaporization of N-butyl-N-methylpyrrolidinium bistrifluorosulfonylimide is determined to be Delta Hvap(298.15 K) = 195+-19 kJ mol-1. The observed heats of vaporization of 1-butyl-3-methylimidazolium dicyanamide (Delta Hvap(298.15 K) = 174+-12 kJ mol-1) and N-butyl-N-methylpyrrolidinium dicyanamide (Delta Hvap(298.15 K) = 171+-12 kJ mol-1) are consistent with reported experimental values using electron impact ionization. The tunable vacuum ultraviolet source has enabled accurate measurement of photoion appearance energies. These appearance energies are in good agreement with MP2 calculations for dissociative photoionization of the ion pair. These experimental heats of vaporization, photoion appearance energies, and ab initio calculations corroborate vaporization of these RTILs as intact cation-anion ion pairs.

  1. Application of ionic liquids in hydrometallurgy.

    Science.gov (United States)

    Park, Jesik; Jung, Yeojin; Kusumah, Priyandi; Lee, Jinyoung; Kwon, Kyungjung; Lee, Churl Kyoung

    2014-08-29

    Ionic liquids, low temperature molten salts, have various advantages manifesting themselves as durable and environmentally friendly solvents. Their application is expanding into various fields including hydrometallurgy due to their unique properties such as non-volatility, inflammability, low toxicity, good ionic conductivity, and wide electrochemical potential window. This paper reviews previous literatures and our recent results adopting ionic liquids in extraction, synthesis and processing of metals with an emphasis on the electrolysis of active/light, rare earth, and platinum group metals. Because the research and development of ionic liquids in this area are still emerging, various, more fundamental approaches are expected to popularize ionic liquids in the metal manufacturing industry.

  2. Orientational dynamics of room temperature ionic liquid/water mixtures: water-induced structure.

    Science.gov (United States)

    Sturlaugson, Adam L; Fruchey, Kendall S; Fayer, Michael D

    2012-02-16

    Optical heterodyne detected optical Kerr effect (OHD-OKE) measurements on a series of 1-alkyl-3-methylimidazolium tetrafluoroborate room-temperature ionic liquids (RTILs) as a function of chain length and water concentration are presented. The pure RTIL reorientational dynamics are identical in form to those of other molecular liquids studied previously by OHD-OKE (two power laws followed by a single exponential decay at long times), but are much slower at room temperature. In contrast, the addition of water to the longer alkyl chain RTILs causes the emergence of a long time biexponential orientational anisotropy decay. Such distinctly biexponential decays have not been seen previously in OHD-OKE experiments on any type of liquid and are analyzed here using a wobbling-in-a-cone model. The slow component for the longer chain RTILs does not obey the Debye-Stokes-Einstein (DSE) equation across the range of solutions, and thus we attribute it to slow cation reorientational diffusion caused by a stiffening of cation alkyl tail-tail associations. The fast component of the decay is assigned to the motions (wobbling) of the tethered imidazolium head groups. The wobbling-in-a-cone analysis provides estimates of the range of angles sampled by the imidazolium head group prior to the long time scale complete orientational randomization. The heterogeneous dynamics and non-DSE behavior observed here should have a significant effect on reaction rates in RTIL/water cosolvent mixtures.

  3. Ionic liquid for high temperature headspace liquid-phase microextraction of chlorinated anilines in environmental water samples.

    Science.gov (United States)

    Peng, Jin-feng; Liu, Jing-fu; Jiang, Gui-bin; Tai, Chao; Huang, Min-jia

    2005-04-22

    Based on the non-volatility of room temperature ionic liquids (IL), 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM][PF6]) IL was employed as an advantageous extraction solvent for high temperature headspace liquid-phase microextraction (LPME) of chloroanilines in environmental water samples. At high temperature of 90 degrees C, 4-chloroaniline, 2-chloroaniline, 3,4-dichloroaniline, and 2,4-dichloroaniline were extracted into a 10 microl drop of [C4MIM][PF6] suspended on the needle of a high-performance liquid chromatography (HPLC) microsyringe held at the headspace of the samples. Then, the IL was injected directly into the HPLC system for determination. Parameters related to LPME were optimized, and high selectivity and low detection limits of the four chlorinated anilines were obtained because the extraction was performed at high temperature in headspace mode and the very high affinity between IL and chlorinated anilines. The proposed procedure was applied for the analysis of the real samples including tap water, river water and wastewater samples from a petrochemical plant and a printworks, and only 3,4-dichloroaniline was detected in the printworks wastewater at 88.2 microg l(-1) level. The recoveries for the four chlorinated anilines in the four samples were all in the range of 81.9-99.6% at 25 microg l(-1) spiked level.

  4. Surface tension of ionic liquids and ionic liquid solutions.

    Science.gov (United States)

    Tariq, Mohammad; Freire, Mara G; Saramago, Benilde; Coutinho, João A P; Lopes, José N Canongia; Rebelo, Luís Paulo N

    2012-01-21

    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).

  5. Aluminium Electrodeposition from Ionic Liquid: Effect of Deposition Temperature and Sonication †

    Science.gov (United States)

    Berretti, Enrico; Giaccherini, Andrea; Martinuzzi, Stefano M.; Innocenti, Massimo; Schubert, Thomas J.S.; Stiemke, Frank M.; Caporali, Stefano

    2016-01-01

    Since their discovery, ionic liquids (ILs) have attracted a wide interest for their potential use as a medium for many chemical processes, in particular electrochemistry. As electrochemical media they allow the electrodeposition of elements that are impossible to reduce in aqueous media. We have investigated the electrodeposition of aluminium from 1-butyl-3-methyl-imidazolium chloride ((Bmim)Cl)/AlCl3 (40/60 mol %) as concerns the effect of deposition parameters on the quality of the deposits. Thick (20 μm) aluminium coatings were electrodeposited on brass substrates at different temperatures and mixing conditions (mechanical stirring and sonication). These coatings were investigated by means of scanning electron microscope, roughness measurements, and X-ray diffraction to assess the morphology and the phase composition. Finally, electrochemical corrosion tests were carried out with the intent to correlate the deposition parameters to the anti-corrosion properties. PMID:28773839

  6. Aluminium Electrodeposition from Ionic Liquid: Effect of Deposition Temperature and Sonication †

    Directory of Open Access Journals (Sweden)

    Enrico Berretti

    2016-08-01

    Full Text Available Since their discovery, ionic liquids (ILs have attracted a wide interest for their potential use as a medium for many chemical processes, in particular electrochemistry. As electrochemical media they allow the electrodeposition of elements that are impossible to reduce in aqueous media. We have investigated the electrodeposition of aluminium from 1-butyl-3-methyl-imidazolium chloride ((BmimCl/AlCl3 (40/60 mol % as concerns the effect of deposition parameters on the quality of the deposits. Thick (20 μm aluminium coatings were electrodeposited on brass substrates at different temperatures and mixing conditions (mechanical stirring and sonication. These coatings were investigated by means of scanning electron microscope, roughness measurements, and X-ray diffraction to assess the morphology and the phase composition. Finally, electrochemical corrosion tests were carried out with the intent to correlate the deposition parameters to the anti-corrosion properties.

  7. Are Ionic Liquids Chemically Stable?

    Science.gov (United States)

    Wang, Binshen; Qin, Li; Mu, Tiancheng; Xue, Zhimin; Gao, Guohua

    2017-05-24

    Ionic liquids have attracted a great deal of interest in recent years, illustrated by their applications in a variety of areas involved with chemistry, physics, biology, and engineering. Usually, the stabilities of ionic liquids are highlighted as one of their outstanding advantages. However, are ionic liquids really stable in all cases? This review covers the chemical stabilities of ionic liquids. It focuses on the reactivity of the most popular imidazolium ionic liquids at structural positions, including C2 position, N1 and N3 positions, and C4 and C5 positions, and decomposition on the imidazolium ring. Additionally, we discuss decomposition of quaternary ammonium and phosphonium ionic liquids and hydrolysis and nucleophilic reactions of anions of ionic liquids. The review aims to arouse caution on potential decomposition of ionic liquids and provides a guide for better utilization of ionic liquids.

  8. A Simple Prediction Method for the Surface Tension of Ionic Liquids as a Function of Temperature

    Science.gov (United States)

    Koller, Thomas M.; Steininger, Corina; Rausch, Michael H.; Fröba, Andreas P.

    2017-11-01

    In this study, a simple prediction method for the surface tension of ionic liquids (ILs) as a function of temperature is developed. Based on a database of experimental surface tension values collected from the literature, first a prediction scheme for the surface tension at a reference temperature of 298.15 K using only information on the density, molar mass, and anion type of the IL is suggested. By combination of this approach with the temperature dependence of the density, an extended prediction scheme describing the temperature dependence of the surface tension of ILs is recommended. The optimized prediction model for the surface tension allows for the prediction of about 3500 temperature-dependent experimental surface tension data of 226 different ILs with a standard deviation of about 7 %. In comparison with fluid-specific prediction methods found in the literature, the developed simple empirical prediction model requires only easily accessible parameters and can be applied for ILs with arbitrary cation and anion combinations. Thus, the proposed prediction method seems to be a valuable engineering tool for the quantitative estimation of the surface tension of ILs.

  9. Extraction of plutonium(IV) by diglycolamide extractants in room temperature ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Prabhu, Dattaprasad R.; Raut, Dhaval R.; Murali, Mallekav S.; Mohapatra, Prasanta K. [Bhabha Atomic Research Centre, Mumbai (India). Radiochemistry Div.

    2017-06-01

    Extraction of Pu(IV) was investigated using solutions of two diglycolamide extractants viz., N,N,N{sup '},N{sup '}-tetra-n-octyldiglycolamide (TODGA) and its branched homolog, N,N,N{sup '},N{sup '}-tetra(2-ethylhexyl) diglycolamide (T2EHDGA), dissolved in two imidazolium based room temperature ionic liquids viz., 1-butyl-3-methylimidazolium bis(trifluoromethanesulphonyl) imide ([C{sub 4}mim][NTf{sub 2}]) and 1-octyl-3-methylimidazolium bis(trifluoromethanesulphonyl) imide ([C{sub 8}mim][NTf{sub 2}]) from aqueous nitric acid medium. The extraction kinetics was found to be extremely slow which is reported for the first time for analogous extraction systems and took as long as 30 h to attain equilibrium D{sub Pu} values. In general, TODGA based solvents showed better extraction of Pu(IV) than the T2EHDGA based solvents, one order of magnitude higher, and though both the ionic liquids ultimately yielded comparable D{sub Pu} values, attainment of equilibrium was slower with [C{sub 4}mim][NTf{sub 2}]. The extracted species conformed to 1:1 for TODGA in both the ionic liquids while a mixture of 1:1 and 1:2 species was observed for T2EHDGA at 1 M HNO{sub 3} which changed to 1:1 species at 4 M HNO{sub 3}. The extracted species is proposed to be (Pu(L){sub x}{sup 4+}){sub IL} (where, L is the extractant and x=1 or 2) at lower acidities suggesting a cation exchange mechanism which changes over to (Pu(NO{sub 3}){sub 4} .L){sub IL} at 4 M HNO{sub 3} conforming to a solvation mechanism for all the systems except for T2EHDGA-[C{sub 8}mim][NTf{sub 2}]. UV-VIS spectroscopic studies were carried out to throw light on the nature of the extracted species.

  10. Protein remains stable at unusually high temperatures when solvated in aqueous mixtures of amino acid based ionic liquids

    DEFF Research Database (Denmark)

    Chevrot, Guillaume; Fileti, Eudes Eterno; Chaban, Vitaly V.

    2016-01-01

    [EMIM][TRP] (5 mol% in water). Upon analyzing the radius of gyration, the solvent-accessible surface area, root-mean-squared deviations, and inter- and intramolecular hydrogen bonds, we found that the mini-protein remains stable at 30–40 K higher temperatures in aqueous amino acid based ionic liquids...

  11. NOVEL FISSION PRODUCT SEPARATION BASED ON ROOM-TEMPERATURE IONIC LIQUIDS

    Energy Technology Data Exchange (ETDEWEB)

    Hussey, Charles L.

    2004-06-01

    The DoE/NE underground storage tanks at Hanford, SRS, and INEEL contain liquid wastes with high concentrations of radioactive species, mainly 137Cs and 90Sr. Because the other components of the liquid waste are mainly sodium nitrate and sodium hydroxide, most of this tank waste can be treated inexpensively as low-level waste if 137Cs and 90Sr can be selectively removed. Many ionophores (crown ether and calixarene compounds) have been synthesized for the purpose of selectively extracting Cs+ and Sr2+ from an aqueous phase into an immiscible organic phase. Recent studies conducted at ORNL1,2 reveal that hydrophobic ionic liquids might be better solvents for extracting metal ions from aqueous solutions with these ionophores than conventional immiscible organic solvents, such as benzene, toluene, and dichloromethane, because both Cs+ and Sr2+ exhibit larger distribution coefficients in the ionic liquids. In addition, the vapor pressures of these ionic liquids are insignificant. Thus, there is little or no vaporization loss of these solvents. Most of the ionic liquids under investigation are relatively nontoxic compared to the hydrocarbon solvents that they replace, classifying them as ''green'' solvents.

  12. Changes of electrochemical properties of polypyrrole when synthesized in a room-temperature ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Dalmolin, Carla, E-mail: carla.dalmolin@udesc.br; Biaggio, Sonia R.; Bocchi, Nerilso; Rocha-Filho, Romeu C.

    2014-09-15

    The room-temperature ionic liquid (RTIL) 1-butyl-3-methylimidazolium tetrafluoroborate, BMIM BF{sub 4}, was employed as electrolyte in the electrosynthesis of thin polypyrrole (PPy) films on a Pt substrate, and the resulting PPy electrodes were electrochemically characterized. Electrochemical impedance spectroscopy (EIS) was used to comparatively investigate the electric behavior of PPy produced in the RTIL and the one produced in a traditional acetonitrile/lithium salt system, and charge–discharge curves in the range 2.0–4.0 V (vs. Li/Li{sup +}) were obtained in a 1.0 M LiBF{sub 4} propylene carbonate solution. Although a reduction of the specific capacity for the PPy obtained in the RTIL was observed, compared to that of the PPy film synthesized in the acetonitrilic electrolyte, its chronopotentiometric profile presented a plateau in the 2.7 V region. This is a remarkable result, considering that a linear decrease in this profile is usually observed for the majority of conducting polymer cathodes. PPy films obtained in BMIM BF{sub 4} presented globular morphology, with a special arrangement of nanoparticles constituting the globules; the EIS results indicated that this nanoscale structure may be contributing to a better definition of the redox characteristics during the PPy charge–discharge processes, as it happens for the well-organized structure of some metal oxides. - Highlights: • PPy was produced in an ionic liquid medium as active material for battery electrodes. • Discharge curves present a plateau not usual for conducting polymer electrodes. • RTIL used as synthesis electrolyte produced PPy with surface nanograins. • Morphological features explain the improved redox properties of PPy electrode. • Electrical properties of PPy grown in RTIL were accessed by impedance measurements.

  13. Transformations of Liquid Metals in Ionic Liquid

    OpenAIRE

    Liu, Fujun; Yu, Yongze; Liu, Jing

    2017-01-01

    Experimental studies were carried out on the motions and transformations of liquid metal in ionic liquid under applied electric field. The induced vortex rings and flows of ionic liquid were determined via the photographs taken sequentially over the experiments. The polarization of electric double layer of liquid metals was employed to explain the flow of ionic liquid with the presence of liquid metal. Unlike former observation of liquid metal machine in conventional solution, no gas bubble w...

  14. Development of an Analytical Method Based on Temperature Controlled Solid-Liquid Extraction Using an Ionic Liquid as Solid Solvent

    Directory of Open Access Journals (Sweden)

    Zhongwei Pan

    2015-12-01

    Full Text Available At the present paper, an analytical method based on temperature controlled solid-liquid extraction (TC-SLE utilizing a synthesized ionic liquid, (N-butylpyridinium hexafluorophosphate, [BPy]PF6, as solid solvent and phenanthroline (PT as an extractant was developed to determine micro levels of Fe2+ in tea by PT spectrophotometry. TC-SLE was carried out in two continuous steps: Fe2+ can be completely extracted by PT-[BPy]PF6 or back-extracted at 80 °C and the two phases were separated automatically by cooling to room temperature. Fe2+, after back-extraction, needs 2 mol/L HNO3 as stripping agent and the whole process was determined by PT spectrophotometry at room temperature. The extracted species was neutral Fe(PTmCl2 (m = 1 according to slope analysis in the Fe2+-[BPy]PF6-PT TC-SLE system. The calibration curve was Y = 0.20856X − 0.000775 (correlation coefficient = 0.99991. The linear calibration range was 0.10–4.50 μg/mL and the limit of detection for Fe2+ is 7.0 × 10−2 μg/mL. In this method, the contents of Fe2+ in Tieguanyin tea were determined with RSDs (n = 5 3.05% and recoveries in range of 90.6%–108.6%.

  15. NOvel Fission Product Separation Based on Room-Temperature Ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Hussey, Charles L.

    2005-11-13

    The effective extraction of Cs+ and Sr2+ into a relatively new and heretofore untested hydrophobic ionic liquid, tri-n-butylmethylammonium bis[(trifluoromethyl)sulfonyl]imide was demonstrated with calix[4]arene-bis(tert-octylbenzo-crown-6) and dicyclohexano-18-crown-6, respectively. The coordinated Cs+ and Sr2+ were subsequently removed from the ionic liquid extraction solvent by an electrochemical reduction process carried out at mercury electrodes. This process is non-destructive, permitting the ionic liquid and ionophores to be recycled. Although the process is based on mercury electrodes, this is a benefit rather than a detriment because the liquid mercury containing the Cs and Sr can be easily transported to another electrochemical cell where the Cs and Sr could be electrochemically recovered from the mercury amalgam and concentrated into a minimum volume of water or some other inexpensive solvent. This should facilitate the development of a suitable waste form for the extracted Cs+ and Sr2+. Thus, the feasibility of the proposed ionic liquid-based extraction cycle for the removal of 137Cs+ and 90Sr2+ from simulated aqueous tank waste was demonstrated.

  16. Ionic liquids in chemical engineering.

    Science.gov (United States)

    Werner, Sebastian; Haumann, Marco; Wasserscheid, Peter

    2010-01-01

    The development of engineering applications with ionic liquids stretches back to the mid-1990s when the first examples of continuous catalytic processes using ionic liquids and the first studies of ionic liquid-based extractions were published. Ever since, the use of ionic liquids has seen tremendous progress in many fields of chemistry and engineering, and the first commercial applications have been reported. The main driver for ionic liquid engineering applications is to make practical use of their unique property profiles, which are the result of a complex interplay of coulombic, hydrogen bonding and van der Waals interactions. Remarkably, many ionic liquid properties can be tuned in a wide range by structural modifications at their cation and anion. This review highlights specific examples of ionic liquid applications in catalysis and in separation technologies. Additionally, the application of ionic liquids as working fluids in process machines is introduced.

  17. Functionalized ionic liquids and their applications

    Energy Technology Data Exchange (ETDEWEB)

    Hariprakasha, Humcha Krishnamurthy; Rangan, Krishnaswamy Kasthuri; Sudarshan, Tirumalai Srinivas

    2018-01-16

    Disclosure of functionalized ionic liquids. Use of disclosed ionic liquids as solvent for carbon dioxide. Use of disclosed ionic liquids as flame retardant. Use of disclosed ionic liquids for coating fabric to obtain flame retardant fabric.

  18. DETERMINATION OF HENRY'S LAW CONSTANTS FOR VOCS IN ROOM TEMPERATURE IONIC LIQUIDS

    Science.gov (United States)

    Ionic liquids (ILs) have been shown to be a newer medium for a wide variety of chemical reactions and are considered as the potential replacements for traditional volatile organic solvents. However, the separation and recovery of organic compounds from ILs has not been systematic...

  19. What Can we learn from Raman spectroscopy and model calculations on room temperature ionic liquids?

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    2006-01-01

    Traditionally ionic liquids involve inorganic hygroscopic substances that need to be contained under protective atmospheres, e.g. in sealed ampoules. Experimental methods to study the chemistry inside closed ampoules are limited, and one popular technique has been and still is Raman scattering be...

  20. Enhanced Esterification Conversion in a Room Temperature Ionic Liquid by Integrated Water Removal with Pervaporation

    Czech Academy of Sciences Publication Activity Database

    Izák, Pavel; Mateus, N.M.M.; Afonso, C. A. M.; Crespo, J.G.

    2005-01-01

    Roč. 41, č. 2 (2005), s. 141-145 ISSN 1383-5866 Institutional research plan: CEZ:AV0Z40720504 Keywords : pervaporation * ionic liquids * esterification reaction Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.752, year: 2005

  1. Synthesis of Ionic Liquid Based Electrolytes, Assembly of Li-ion Batteries, and Measurements of Performance at High Temperature.

    Science.gov (United States)

    Lin, Xinrong; Chapman Varela, Jennifer; Grinstaff, Mark W

    2016-12-20

    The chemical instability of the traditional electrolyte remains a safety issue in widely used energy storage devices such as Li-ion batteries. Li-ion batteries for use in devices operating at elevated temperatures require thermally stable and non-flammable electrolytes. Ionic liquids (ILs), which are non-flammable, non-volatile, thermally stable molten salts, are an ideal replacement for flammable and low boiling point organic solvent electrolytes currently used today. We herein describe the procedures to: 1) synthesize mono- and di-phosphonium ionic liquids paired with chloride or bis(trifluoromethane)sulfonimide (TFSI) anions; 2) measure the thermal properties and stability of these ionic liquids by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA); 3) measure the electrochemical properties of the ionic liquids by cyclic voltammetry (CV); 4) prepare electrolytes containing lithium bis(trifluoromethane)sulfonamide; 5) measure the conductivity of the electrolytes as a function of temperature; 6) assemble a coin cell battery with two of the electrolytes along with a Li metal anode and LiCoO2 cathode; and 7) evaluate battery performance at 100 °C. We additionally describe the challenges in execution as well as the insights gained from performing these experiments.

  2. Liquid-liquid extraction of Pu(IV), U(VI) and Am(III) using malonamide in room temperature ionic liquid as diluent.

    Science.gov (United States)

    Rout, Alok; Venkatesan, K A; Srinivasan, T G; Vasudeva Rao, P R

    2012-06-30

    The extraction behavior of U(VI), Pu(IV) and Am(III) from nitric acid medium by a solution of N,N-dimethyl-N,N-dioctyl-2-(2-hexyloxyethyl)malonamide (DMDOHEMA) in the room temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (C(4)mimNTf(2)), was studied. The distribution ratio of these actinides in DMDOHEMA/C(4)mimNTf(2) was measured as a function of various parameters such as the concentration of nitric acid, DMDOHEMA, NTf(2)(-), alkyl chain length of ionic liquid. The extraction of actinides in the absence of DMDOHEMA was insignificant and the distribution ratio achieved in conjunction with C(4)mimNTf(2), was remarkable. The separation factor of U(VI) and Pu(IV) achieved with the use of DMDOHEMA, ionic liquid was compared with Am(III) and other fission products. The stoichiometry of the metal-solvate was determined to be 1:2 for U(VI) and Pu(IV) and 1:3 for Am(III). Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Correlation between hydrogen bond basicity and acetylene solubility in room temperature ionic liquids.

    Science.gov (United States)

    Palgunadi, Jelliarko; Hong, Sung Yun; Lee, Jin Kyu; Lee, Hyunjoo; Lee, Sang Deuk; Cheong, Minserk; Kim, Hoon Sik

    2011-02-10

    Room temperature ionic liquids (RTILs) are proposed as the alternative solvents for the acetylene separation in ethylene generated from the naphtha cracking process. The solubility behavior of acetylene in RTILs was examined using a linear solvation energy relationship based on Kamlet-Taft solvent parameters including the hydrogen-bond acidity or donor ability (α), the hydrogen-bond basicity or acceptor ability (β), and the polarity/polarizability (π*). It is found that the solubility of acetylene linearly correlates with β value and is almost independent of α or π*. The solubility of acetylene in RTILs increases with increasing hydrogen-bond acceptor (HBA) ability of the anion, but is little affected by the nature of the cation. Quantum mechanical calculations demonstrate that the acidic proton of acetylene specifically forms hydrogen bond with a basic oxygen atom on the anion of a RTIL. On the other hand, although C-H···π interaction is plausible, all optimized structures indicate that the acidic protons on the cation do not specifically associate with the π cloud of acetylene. Thermodynamic analysis agrees well with the proposed correlation: the higher the β value of a RTIL is, the more negative the enthalpy of acetylene absorption in the RTIL is.

  4. Pyrrolidinium Ionic Liquid Crystals

    OpenAIRE

    Goossens, Karel; Lava, Kathleen; Nockemann, Peter; Van Hecke, Kristof; Van Meervelt, Luc; Driesen, Kris; Görller-Walrand, Christiane; Binnemans, Koen; Cardinaels, Thomas

    2009-01-01

    N-Alkyl-N-methylpyrrolidinium cations have been used for the design of ionic liquid crystals, including a new type of uranium-containing metallomesogen. Pyrrolidinium salts with bromide, bis(trifluoromethylsulfonyl)-imide, tetrafluoroborate, hexafluorophosphate, thiocyanate, tetrakis(2-thenoyltrifluoroacetonato)europate(III) and tetrabromouranyl] counteranions were prepared. For the bromide salts and tetrabromouranyl compounds, the chain length of the alkyl group CnH2n+1 was varied from eight...

  5. Temperature dependence of multilayering at the free surface of ionic liquids probed by X-ray reflectivity measurements.

    Science.gov (United States)

    Nishi, Naoya; Uruga, Tomoya; Tanida, Hajime; Kakiuchi, Takashi

    2011-06-21

    The effect of the temperature on the surface layering of ionic liquids has been studied for two ionic liquids, trioctylmethylammonium bis(nonafluorobutanesulfonyl)amide([TOMA(+)][C(4)C(4)N(-)]) and trihexyltetradecylphosphonium bis(nonafluorobutanesulfonyl)amide ([THTDP(+)][C(4)C(4)N(-)]), using X-ray reflectivity measurements at 285, 300, and 315 K. Both [TOMA(+)][C(4)C(4)N(-)] and [THTDP(+)][C(4)C(4)N(-)] develop multilayers at the surface. The structure of the multilayers at the [TOMA(+)][C(4)C(4)N(-)] surface shows little temperature-dependent change, whereas that at the [THTDP(+)][C(4)C(4)N(-)] surface clearly becomes diffused with increasing temperature. The different temperature dependence seems to be related to the difference in the recently reported ultraslow dynamics of the interfacial structure of [TOMA(+)][C(4)C(4)N(-)] and [THTDP(+)][C(4)C(4)N(-)] at the ionic liquid|water interface. © 2011 American Chemical Society

  6. Substitution of conventional high-temperature syntheses of inorganic compounds by near-room-temperature syntheses in ionic liquids

    KAUST Repository

    Groh, Matthias Friedrich

    2013-01-01

    The high-temperature syntheses of the low-valent halogenides P2I4, Te2Br, α-Te4I4, Te4(Al2Cl7)2, Te4(Bi6Cl20), Te8(Bi4Cl14),Bi8(AlCl4)2, Bi6Cl7,and Bi6Br7, as well as of WSCl4 andWOCl4 have been replaced by resource-efficient low-temperature syntheses in room temperature ionic liquids (RTILs). The simple one-pot syntheses generally do not require elaborate equipment such as twozone furnaces or evacuated silica ampoules. Compared to the published conventional approaches, reduction of reaction time (up to 80%) and temperature (up to 500 K) and, simultaneously, an increase in yield were achieved. In the majority of cases, the solid products were phase-pure. X-Ray diffraction on single crystals (redetermination of 11 crystal structures) has demonstrated that the quality of the crystals from RTILs is comparable to that of products obtained by chemical transport reactions. © 2013 Verlag der Zeitschrift für Naturforschung, Tübingen.

  7. IONIC LIQUIDS: PREPARATIONS AND LIMITATIONS

    Directory of Open Access Journals (Sweden)

    Dzulkefly Kuang Abdullah

    2010-11-01

    Full Text Available Ionic liquids are considered as an ideal alternative to volatile organic solvents and chemical industries in the future,because they are non-volatile. Ionic liquids are also considered as new novel chemical agents and widely regarded as agreener alternative to many commonly used solvents. Ionic liquids have been studied for a wide range of syntheticapplications and have attracted considerable interest for use as electrolytes in the areas of organic synthesis, catalysis,solar cell, fuel cells, electrodeposition and supercapacitors. However, some ionic liquids suffer from more or less somedrawbacks such as toxicity, preparation and high cost in the process for use. Most recently, three types of ionic liquidsare attracted much attentions specifically traditional ionic liquid, protic ionic liquid and deep eutectic solvent, wheretheir preparation, mechanism and limitation were differentiated. However, those liquids are having their ownadvantages and limitations based on applications. Traditional ionic liquid and protic ionic liquid are highly cost andtoxic for applied engineering research, but they consist of micro-biphasic systems composed of ionic compounds whichhave more varieties in the applications. The deep eutectic solvent is very economic for large-scale possessing but thereare only limited ionic mixtures to certain application such as electrochemistry.

  8. Dielectric study on mixtures of ionic liquids.

    Science.gov (United States)

    Thoms, E; Sippel, P; Reuter, D; Weiß, M; Loidl, A; Krohns, S

    2017-08-07

    Ionic liquids are promising candidates for electrolytes in energy-storage systems. We demonstrate that mixing two ionic liquids allows to precisely tune their physical properties, like the dc conductivity. Moreover, these mixtures enable the gradual modification of the fragility parameter, which is believed to be a measure of the complexity of the energy landscape in supercooled liquids. The physical origin of this index is still under debate; therefore, mixing ionic liquids can provide further insights. From the chemical point of view, tuning ionic liquids via mixing is an easy and thus an economic way. For this study, we performed detailed investigations by broadband dielectric spectroscopy and differential scanning calorimetry on two mixing series of ionic liquids. One series combines an imidazole based with a pyridine based ionic liquid and the other two different anions in an imidazole based ionic liquid. The analysis of the glass-transition temperatures and the thorough evaluations of the measured dielectric permittivity and conductivity spectra reveal that the dynamics in mixtures of ionic liquids are well defined by the fractions of their parent compounds.

  9. Ratiometric Optical Temperature Sensor Using Two Fluorescent Dyes Dissolved in an Ionic Liquid Encapsulated by Parylene Film

    Directory of Open Access Journals (Sweden)

    Isao Shimoyama

    2013-03-01

    Full Text Available A temperature sensor that uses temperature-sensitive fluorescent dyes is developed. The droplet sensor has a diameter of 40 µm and uses 1 g/L of Rhodamine B (RhB and 0.5 g/L of Rhodamine 110 (Rh110, which are fluorescent dyes that are dissolved in an ionic liquid (1-ethyl-3-methylimidazolium ethyl sulfate to function as temperature indicators. This ionic liquid is encapsulated using vacuum Parylene film deposition (which is known as the Parylene-on-liquid-deposition (PoLD method. The droplet is sealed by the chemically stable and impermeable Parylene film, which prevents the dye from interacting with the molecules in the solution and keeps the volume and concentration of the fluorescent material fixed. The two fluorescent dyes enable the temperature to be measured ratiometrically such that the droplet sensor can be used in various applications, such as the wireless temperature measurement of microregions. The sensor can measure the temperature of such microregions with an accuracy of 1.9 °C, a precision of 3.7 °C, and a fluorescence intensity change sensitivity of 1.0%/K. The sensor can measure temperatures at different sensor depths in water, ranging from 0 to 850 µm. The droplet sensor is fabricated using microelectromechanical system (MEMS technology and is highly applicable to lab-on-a-chip devices.

  10. Metathesis and hydroformylation reactions in ionic liquids.

    OpenAIRE

    2008-01-01

    Ionic liquids (ILs), consisting of ions that are liquid at ambient temperatures, can act as solvents for a broad spectrum of chemical processes. These ionic liquids are attracting increasing attention from industry because they promise significant environmental as well as product and process benefits. ILs were used as solvents for two industrially important homogeneous reactions namely metathesis of 1-octene and the hydroformylation of vinyl acetate. In the metathesis of 1-octene, several rea...

  11. Structure and dynamics of POPC bilayers in water solutions of room temperature ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Benedetto, Antonio [School of Physics, University College Dublin, Dublin 4 (Ireland); Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen (Switzerland); Bingham, Richard J. [York Centre for Complex Systems Analysis, University of York, York YO10 5GE (United Kingdom); Ballone, Pietro [Center for Life Nano Science @Sapienza, Istituto Italiano di Tecnologia (IIT), 00185 Roma (Italy); Department of Physics, Università di Roma “La Sapienza,” 00185 Roma (Italy)

    2015-03-28

    Molecular dynamics simulations in the NPT ensemble have been carried out to investigate the effect of two room temperature ionic liquids (RTILs), on stacks of phospholipid bilayers in water. We consider RTIL compounds consisting of chloride ([bmim][Cl]) and hexafluorophosphate ([bmim][PF{sub 6}]) salts of the 1-buthyl-3-methylimidazolium ([bmim]{sup +}) cation, while the phospholipid bilayer is made of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). Our investigations focus on structural and dynamical properties of phospholipid and water molecules that could be probed by inelastic and quasi-elastic neutron scattering measurements. The results confirm the fast incorporation of [bmim]{sup +} into the lipid phase already observed in previous simulations, driven by the Coulomb attraction of the cation for the most electronegative oxygens in the POPC head group and by sizeable dispersion forces binding the neutral hydrocarbon tails of [bmim]{sup +} and of POPC. The [bmim]{sup +} absorption into the bilayer favours the penetration of water into POPC, causes a slight but systematic thinning of the bilayer, and further stabilises hydrogen bonds at the lipid/water interface that already in pure samples (no RTIL) display a lifetime much longer than in bulk water. On the other hand, the effect of RTILs on the diffusion constant of POPC (D{sub POPC}) does not reveal a clearly identifiable trend, since D{sub POPC} increases upon addition of [bmim][Cl] and decreases in the [bmim][PF{sub 6}] case. Moreover, because of screening, the electrostatic signature of each bilayer is only moderately affected by the addition of RTIL ions in solution. The analysis of long wavelength fluctuations of the bilayers shows that RTIL sorption causes a general decrease of the lipid/water interfacial tension and bending rigidity, pointing to the destabilizing effect of RTILs on lipid bilayers.

  12. Spectroscopic Study of Solvation Properties of Room-Temperature Ionic Liquids and Solvent Effect on Bimolecular Fluorescence Quenching Reaction at High Pressures

    National Research Council Canada - National Science Library

    KOMETANI, Noritsugu; MINAMIKAWA, Yoshinori

    2013-01-01

      The solvation properties of some room-temperature ionic liquids (RTILs) and the solvent effect on bimolecular fluorescence quenching reaction have been examined at high pressures ranging from 0.1 to 300 MPa...

  13. Ionic Liquids to Replace Hydrazine

    Science.gov (United States)

    Koelfgen, Syri; Sims, Joe; Forton, Melissa; Allan, Barry; Rogers, Robin; Shamshina, Julia

    2011-01-01

    A method for developing safe, easy-to-handle propellants has been developed based upon ionic liquids (ILs) or their eutectic mixtures. An IL is a binary combination of a typically organic cation and anion, which generally produces an ionic salt with a melting point below 100 deg C. Many ILs have melting points near, or even below, room temperature (room temperature ionic liquids, RTILs). More importantly, a number of ILs have a positive enthalpy of formation. This means the thermal energy released during decomposition reactions makes energetic ILs ideal for use as propellants. In this specific work, to date, a baseline set of energetic ILs has been identified, synthesized, and characterized. Many of the ILs in this set have excellent performance potential in their own right. In all, ten ILs were characterized for their enthalpy of formation, density, melting point, glass transition point (if applicable), and decomposition temperature. Enthalpy of formation was measured using a microcalorimeter designed specifically to test milligram amounts of energetic materials. Of the ten ILs characterized, five offer higher Isp performance than hydrazine, ranging between 10 and 113 seconds higher than the state-of-the-art propellant. To achieve this level of performance, the energetic cations 4- amino-l,2,4-triazolium and 3-amino-1,2,4-triazolium were paired with various anions in the nitrate, dicyanamide, chloride, and 3-nitro-l,2,4-triazole families. Protonation, alkylation, and butylation synthesis routes were used for creation of the different salts.

  14. Molecular Simulations of Anion and Temperature Dependence on Structure and Dynamics of 1-Hexyl-3-methylimidazolium Ionic Liquids.

    Science.gov (United States)

    Ramya, K R; Kumar, Praveen; Venkatnathan, Arun

    2015-11-19

    In this study, we examine the effect of various anions and temperature on structure and dynamics of 1-hexyl-3-methylimidazolium ionic liquids (ILs) from molecular dynamics simulations. The structural properties show that ILs containing smaller anions like Cl(-) and Br(-) are relatively higher cation-anion interactions, compared to ILs containing larger anions like OTf(-) and NTf2(-). In all ILs, the spatial distribution of anions is closer to the acidic hydrogen atom of the cation compared to the two nonacidic hydrogen atoms of the cation. The diffusion coefficients of cations and anions (ionic conductivity) increase with anionic size. At each temperature, the cationic and anionic diffusions and ionic conductivity are lowest in ILs containing anions like Cl(-) and Br(-) and highest in ILs containing anions like BF4(-), OTf(-), and NTf2(-). Consistent with experiments, simulations predict that ILs with an intermediate size BF4(-) anion show the highest cationic and anionic diffusion (and ionic conductivity). At each temperature, the interactions between ion pairs of each IL show that a decrease in ion-pair lifetimes is directly related to the increase in diffusion coefficients and conductivity in ILs, suggesting that characterization of ion-pair lifetimes is sufficient to validate the trends seen in dynamical properties of ILs.

  15. Structure and dynamics of room temperature ionic liquids with bromide anion: results from 81Br NMR spectroscopy.

    Science.gov (United States)

    Endo, Takatsugu; Imanari, Mamoru; Hidaka, Yuki; Seki, Hiroko; Nishikawa, Keiko; Sen, Sabyasachi

    2015-05-01

    We report the results of a comprehensive (81)Br NMR spectroscopic study of the structure and dynamics of two room temperature ionic liquids (RTILs), 1-butyl-3-methylimidazolium bromide ([C(4)mim]Br) and 1-butyl-2,3-dimethylimidazolium bromide ([C(4)C(1)mim]Br), in both liquid and crystalline states. NMR parameters in the gas phase are also simulated for stable ion pairs using quantum chemical calculations. The combination of (81)Br spin-lattice and spin-spin relaxation measurements in the motionally narrowed region of the stable liquid state provides information on the correlation time of the translational motion of the cation. (81) Br quadrupolar coupling constants (C(Q)) of the two RTILs were estimated to be 6.22 and 6.52 MHz in the crystalline state which were reduced by nearly 50% in the liquid state, although in the gas phase, the values are higher and span the range of 7-53 MHz depending on ion pair structure. The C(Q) can be correlated with the distance between the cation-anion pairs in all the three states. The (81)Br C(Q) values of the bromide anion in the liquid state indicate the presence of some structural order in these RTILs, the degree of which decreases with increasing temperature. On the other hand, the ionicity of these RTILs is estimated from the combined knowledge of the isotropic chemical shift and the appropriate mean energy of the excited state. [C(4)C(1)mim]Br has higher ionicity than [C(4)mim]Br in the gas phase, while the situation is reverse for the liquid and the crystalline states. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Application of Ionic Liquids in Hydrometallurgy

    Directory of Open Access Journals (Sweden)

    Jesik Park

    2014-08-01

    Full Text Available Ionic liquids, low temperature molten salts, have various advantages manifesting themselves as durable and environmentally friendly solvents. Their application is expanding into various fields including hydrometallurgy due to their unique properties such as non-volatility, inflammability, low toxicity, good ionic conductivity, and wide electrochemical potential window. This paper reviews previous literatures and our recent results adopting ionic liquids in extraction, synthesis and processing of metals with an emphasis on the electrolysis of active/light, rare earth, and platinum group metals. Because the research and development of ionic liquids in this area are still emerging, various, more fundamental approaches are expected to popularize ionic liquids in the metal manufacturing industry.

  17. Free radical (co)polymerization of methyl methacrylate and styrene in room temperature ionic liquids

    Science.gov (United States)

    Zhang, Hongwei

    Conventional free radical polymerizations were carried out in a variety of room temperature ionic liquids (RTILs). Generally, methyl methacrylate (MMA) and styrene (St) were used as typical monomers to compare the polymerization behavior both in RTILs and in common volatile organic compound solvents (VOCs). In most cases, it was observed that both yields and molecular weights are enhanced in the RTIL. While we believe the "diffusion-controlled termination" mechanism makes the termination of the radical propagating chains difficult due to the highly viscous nature of RTIL, other researchers have suggested that the rapid polymerization rates are due to the high polarity of these reaction media. By employing more than a dozen RTILs with a wide range of anions and cations, we attempted to correlate the viscosity and polarity of the RTILs with the molecular weights and polymerization rates. This correlation was not successful, suggesting that other parameters may also play a role in affecting the polymerization behavior. Other kinds of polymerizations have also been attempted including nitroxide-mediated living radical polymerizations of St and MMA in 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF6), and redox initiation system initiated polymerization of MMA through redox pair formed by cation of trihexyl-tetradecyl-phosphonium bis(2,4,4-trimethylpentyl) phosphinate ([H3TDP] [(PM3) 2P]) and BPO. The formation of PSt-b-PMMA by sequential monomer addition through the standard free radical polymerization mechanism, using BPO as initiator, can be realized in [BMIM]PF6 due to the insolubility of polymerized first block---PSt in [BMIM]PF6. The macroradicals wrapped inside the chain coils have prolonged lifetimes because of the diminished termination, which allow some of these radicals to initiate polymerization of MMA at room temperature to form diblock copolymer. Solvents effects on reactivity ratios for free radical statistical copolymerization have been

  18. Specialist gelator for ionic liquids.

    Science.gov (United States)

    Hanabusa, Kenji; Fukui, Hiroaki; Suzuki, Masahiro; Shirai, Hirofusa

    2005-11-08

    Cyclo(l-beta-3,7-dimethyloctylasparaginyl-L-phenylalanyl) (1) and cyclo(L-beta-2-ethylhexylasparaginyl-L-phenylalanyl) (2), prepared from L-asparaginyl-L-phenylalanine methyl ester, have been found to be specialist gelators for ionic liquids. They can gel a wide variety of ionic liquids, including imizazolium, pyridinium, pyrazolidinium, piperidinium, morpholinium, and ammonium salts. The mean minimum gel concentrations (MGCs) necessary to make gels at 25 degrees C were determined for ionic liquids. The gel strength increased at a rate nearly proportional to the concentration of added gelator. The strength of the transparent gel of 1-butylpyridinium tetrafluoroborate ([C(4)py]BF(4)), prepared at a concentration of 60 g L(-1) (gelator 1/[C(4)py]BF(4)), was ca. 1500 g cm(-2). FT-IR spectroscopy indicated that a driving force for gelation was intermolecular hydrogen bonding between amides and that the phase transition from gel to liquid upon heating was brought about by the collapse of hydrogen bonding. The gels formed from ionic liquids were very thermally stable; no melting occurs up to 140 degrees C when the gels were prepared at a concentration of 70 g L(-1) (gelator/ionic liquid). The ionic conductivities of the gels were nearly the same as those of pure ionic liquids. The gelator had electrochemical stability and a wide electrochemical window. When the gels were prepared from ionic liquids containing propylene carbonate, the ionic conductivities of the resulting gels increased to levels rather higher than those of pure ionic liquids. The gelators also gelled ionic liquids containing supporting electrolytes.

  19. Differential solubility of ethylene and acetylene in room-temperature ionic liquids: a theoretical study.

    Science.gov (United States)

    Zhao, Xu; Xing, Huabin; Yang, Qiwei; Li, Rulong; Su, Baogen; Bao, Zongbi; Yang, Yiwen; Ren, Qilong

    2012-04-05

    The room-temperature ionic liquids (RTILs) have potential in realizing the ethylene (C(2)H(4)) and acetylene (C(2)H(2)) separation and avoiding solvent loss and environmental pollution compared with traditional solvents. The interaction mechanisms between gases and RTILs are important for the exploration of new RTILs for gas separation; thus, they were studied by quantum chemical calculation and molecular dynamics simulation in this work. The optimized geometries were obtained for the complexes of C(2)H(4)/C(2)H(2) with anions (Tf(2)N(-), BF(4)(-), and OAc(-)), cation (bmim(+)), and their ion pairs, and the analysis for geometry, interaction energy, natural bond orbital (NBO), and atoms in molecules (AIM) was performed. The quantum chemical calculation results show that the hydrogen-bonding interaction between the gas molecule and anion is the dominant factor in determining the solubility of C(2)H(2) in RTILs. However, the hydrogen-bonding interaction, the p-π interaction in C(2)H(4)-anion, and the π-π interaction in C(2)H(4)-cation are weak and comparable, which all affect the solubility of C(2)H(4) in RTILs with comparable contribution. The calculated results for the distance of H(gas)···X (X = O or F in anions), the BSSE-corrected interaction energy, the electron density of H(gas)···X at the bond critical point (ρ(BCP)), and the relative second-order perturbation stabilization energy (E(2)) are consistent with the experimental data that C(2)H(2) is more soluble than C(2)H(4) in the same RTILs and the solubility of C(2)H(4) in RTILs has the following order: [bmim][Tf(2)N] > [bmim][OAc] > [bmim][BF(4)]. The calculated results also agree with the order of C(2)H(2) solubility in different RTILs that [bmim][OAc] > [bmim][BF(4)] > [bmim][Tf(2)N]. Furthermore, the calculation results indicate that there is strong C(2)H(2)-RTIL interaction, which cannot be negligible compared to the RTIL-RTIL interaction; thus, the regular solution theory is probably not

  20. Microfluidic room temperature ionic liquid droplet generation depending on the hydrophobicity and interfacial tension

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Jung Wook; Chang, Woo-Jin [University of Wisconsin-Milwaukee, Milwaukee (United States); Choi, Joo Hyung; Koo, Yoon Mo [Department of Biological Engineering, Incheon (Korea, Republic of); Choi, Bum Joon; Lee, Gyu Do; Lee, Sang Woo [Yonsei University, Wonju (Korea, Republic of)

    2016-01-15

    We have characterized micro-droplet generation using water immiscible hexafluorophosphate ([PF{sub 6}])- and bis(trifluoro methylsulfonyl)imide ([Tf{sub 2}N])-based room temperature ionic liquids (RTILs). The interfacial tension between total 7 RTILs and phosphate buffered saline (PBS) was measured using a tensiometer for the first time. PBS is one of the most commonly used buffer solutions in cell-related researches. The measured interfacial tension ranges from 8.51 to 11.62 and from 9.56 to 13.19 for [Tf{sub 2}N]- and [PF{sub 6}]-based RTILs, respectively. The RTILs micro-droplets were generated in a microfluidic device. The micro-droplet size and generation frequency were determined based on continuous monitoring of light transmittance at the interface in microchannel. The size of RTIL micro-droplets was inversely proportional to the increase of PBS solution flow rate and RTILs hydrophobicity, while droplet generation frequency was proportional to those changes. The measured size of RTILs droplets ranged from 0.6 to 10.5 nl, and from 1.0 to 17.1 nl for [Tf{sub 2}N]- and [PF{sub 6}]-based RTILs, respectively. The measured frequency of generated RTILs droplets ranged from 2.3 to 37.2 droplet/min, and from 2.7 to 17.1 droplet/min for [Tf{sub 2}N]- and [PF{sub 6}]-based RTILs, respectively. The capillary numbers were calculated depending on the RTILs, and ranged from 0.51x10{sup -3} to 1.06x10{sup -3} and from 5.00x10{sup -3} to 8.65x10{sup -3}, for [Tf{sub 2}N]- and [PF{sub 6}]-based RTILs, respectively. The interfacial tension between RTILs and PBS will contribute to developing bioprocesses using immiscible RTILs. Also, the RTILs micro-droplets will enable the high-throughput monitoring of various biological and chemical reactions using RTILs as new reaction media.

  1. Selective gas absorption by ionic liquids

    DEFF Research Database (Denmark)

    Shunmugavel, Saravanamurugan; Kegnæs, Søren; Due-Hansen, Johannes

    2010-01-01

    Reversible absorption performance for the flue gas components CO 2, NO and SO2 has been tested for several different ionic liquids (ILs) at different temperatures and flue gas compositions. Furthermore, different porous, high surface area carriers have been applied as supports for the ionic liquids...... to obtain Supported Ionic Liquid-Phase (SILP) absorber materials. The use of solid SILP absorbers with selected ILs were found to significantly improve the absorption capacity and sorption dynamics at low flue gas concentration, thus making the applicability of ILs viable in technical, continuous flow...... processes for flue gas cleaning. The results show that CO 2, NO and SO2 can be reversible and selective absorbed using different ILs and that Supported Ionic Liquid-Phase (SILP) absorbers are promising materials for industrial flue gas cleaning. Absorption/desorption dynamics can be tuned by temperatures...

  2. Fast Conversion of Ionic Liquids and Poly(Ionic Liquid)s into Porous Nitrogen-Doped Carbons in Air

    OpenAIRE

    Yongjun Men; Martina Ambrogi; Baohang Han; Jiayin Yuan

    2016-01-01

    Ionic liquids and poly(ionic liquid)s have been successfully converted into nitrogen-doped porous carbons with tunable surface area up to 1200 m2/g at high temperatures in air. Compared to conventional carbonization process conducted under inert gas to produce nitrogen-doped carbons, the new production method was completed in a rather shorter time without noble gas protection.

  3. Electrolytic conductivity and molar heat capacity of two aqueous solutions of ionic liquids at room-temperature: Measurements and correlations

    Energy Technology Data Exchange (ETDEWEB)

    Lin Peiyin [R and D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung Li 32023, Taiwan (China); Soriano, Allan N. [R and D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung Li 32023, Taiwan (China); School of Chemical Engineering and Chemistry, Mapua Institute of Technology, Manila 1002 (Philippines); Leron, Rhoda B. [R and D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung Li 32023, Taiwan (China); Li Menghui, E-mail: mhli@cycu.edu.t [R and D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung Li 32023, Taiwan (China)

    2010-08-15

    As part of our systematic study on physicochemical characterization of ionic liquids, in this work, we report new measurements of electrolytic conductivity and molar heat capacity for aqueous solutions of two 1-ethyl-3-methylimidazolium-based ionic liquids, namely: 1-ethyl-3-methylimidazolium dicyanamide and 1-ethyl-3-methylimidazolium 2-(2-methoxyethoxy) ethylsulfate, at normal atmospheric condition and for temperatures up to 353.2 K. The electrolytic conductivity and molar heat capacity were measured by a commercial conductivity meter and a differential scanning calorimeter (DSC), respectively. The estimated experimental uncertainties for the electrolytic conductivity and molar heat capacity measurements were {+-}1% and {+-}2%, respectively. The property data are reported as functions of temperature and composition. A modified empirical equation from another researcher was used to correlate the temperature and composition dependence of the our electrolytic conductivity results. An excess molar heat capacity expression derived using a Redlich-Kister type equation was used to represent the temperature and composition dependence of the measured molar heat capacity and calculated excess molar heat capacity of the solvent systems considered. The correlations applied represent the our measurements satisfactorily as shown by an acceptable overall average deviation of 6.4% and 0.1%, respectively, for electrolytic conductivity and molar heat capacity.

  4. The electrochemical reduction of the purines guanine and adenine at platinum electrodes in several room temperature ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Zanoni, Maria Valnice Boldrin, E-mail: boldrinv@iq.unesp.br [Department of Analytical Chemistry, Institute of Chemistry, University of Sao Paulo State, Araraquara, R. Prof. Francisco Degni, CP 355, 14801-970, SP (Brazil); Rogers, Emma I. [Department of Chemistry, Physical and Theoretical Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ (United Kingdom); Hardacre, Christopher, E-mail: c.hardacre@qub.ac.uk [School of Chemistry and Chemical Engineering/QUILL, Queen' s University Belfast, Belfast, Northern Ireland BT9 5AG (United Kingdom); Compton, Richard G., E-mail: richard.compton@chem.ox.ac.uk [Department of Chemistry, Physical and Theoretical Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ (United Kingdom)

    2010-02-05

    The reduction of guanine was studied by microelectrode voltammetry in the room temperature ionic liquids (RTILs) N-hexyltriethylammonium bis (trifluoromethanesulfonyl) imide [N{sub 6,2,2,2}][N(Tf){sub 2}], 1-butyl-3-methylimidazolium hexafluorosphosphate [C{sub 4}mim][PF{sub 6}], N-butyl-N-methyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide [C{sub 4}mpyrr][N(Tf){sub 2}], 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C{sub 4}mim][N(Tf){sub 2}], N-butyl-N-methyl-pyrrolidinium dicyanamide [C{sub 4}mpyrr][N(NC){sub 2}] and tris(P-hexyl)-tetradecylphosphonium trifluorotris(pentafluoroethyl)phosphate [P{sub 14,6,6,6}][FAP] on a platinum microelectrode. In [N{sub 6,2,2,2}][NTf{sub 2}] and [P{sub 14,6,6,6}][FAP], but not in the other ionic liquids studied, guanine reduction involves a one-electron, diffusion-controlled process at very negative potential to produce an unstable radical anion, which is thought to undergo a dimerization reaction, probably after proton abstraction from the cation of the ionic liquid. The rate of this subsequent reaction depends on the nature of the ionic liquid, and it is faster in the ionic liquid [P{sub 14,6,6,6}][FAP], in which the formation of the resulting dimer can be voltammetrically monitored at less negative potentials than required for the reduction of the parent molecule. Adenine showed similar behaviour to guanine but the pyrimidines thymine and cytosine did not; thymine was not reduced at potentials less negative than required for solvent (RTIL) decomposition while only a poorly defined wave was seen for cytosine. The possibility for proton abstraction from the cation in [N{sub 6,2,2,2}][NTf{sub 2}] and [P{sub 14,6,6,6}][FAP] is noted and this is thought to aid the electrochemical dimerization process. The resulting rapid reaction is thought to shift the reduction potentials for guanine and adenine to lower values than observed in RTILs where the scope for proton abstraction is not present. Such shifts are

  5. Photodetachment, electron cooling, and recombination, in a series of neat aliphatic room temperature ionic liquids.

    Science.gov (United States)

    Molins i Domenech, Francesc; Healy, Andrew T; Blank, David A

    2015-08-14

    Transient absorption following photodetachment of a series of neat methyl-alkyl-pyrrolidinium bis(trifluoromethylsulfonyl)amides at 6.20 eV was measured with sub-picosecond time resolution in the visible and near-IR portions of the spectrum. This series spans the onset of structuring in the liquids in the form of polarity alternation. Excitation promotes the electron into a delocalized state with a very large reactive radius. Strong transient absorption is observed in the visible spectrum with a ∼700 fs lifetime, and much weaker, long-lived absorption is observed in the near-IR spectrum. Absorption in the visible is shown to be consistent with the hole, and absorption in the near-IR is assigned to the free solvated electron. Yield of free electrons is estimated at ∼4%, is insensitive to the size of the cation, and is determined in less than 1 ps. Solvation of free electrons depends strongly on the size of the cation and correlates well with the viscosity of the liquid. In addition to radiolytic stability of the aliphatic cations, ultrafast, efficient recombination of separated charge in NTf2 (-) based ionic liquids following photo-excitation near the band-gap may prevent subsequent reactive damage associated with anions.

  6. Effect of temperature and cationic chain length on the physical properties of ammonium nitrate-based protic ionic liquids.

    Science.gov (United States)

    Capelo, S Bouzón; Méndez-Morales, T; Carrete, J; López Lago, E; Vila, J; Cabeza, O; Rodríguez, J R; Turmine, M; Varela, L M

    2012-09-13

    We report a systematic study of the effect of the cationic chain length and degree of hydrogen bonding on several equilibrium and transport properties of the first members of the alkylammonium nitrate protic ionic liquids (PILs) family (ethylammonium, propylammonium, and butylammonium nitrate) in the temperature range between 10 and 40 °C. These properties were observed by means of several experimental techniques, including density, surface tension, refractometry, viscosimetry, and conductimetry. The dilatation coefficients and compressibilities, as well as the Rao coefficients, were calculated, and an increase of these magnitudes with alkyl chain length was detected. Moreover, the surface entropies and enthalpies of the studied PILs were analyzed, and the temperature dependence of the surface tension was observed to be describable by means of a harmonic oscillator model with surface energies and critical temperatures that are increasing functions of the cationic chain length. Moreover, the refractive indexes were measured and the thermo-optic coefficient and Abbe numbers were calculated, and the contribution of the electrostrictive part seemed to dominate the temperature dependence of the electric polarization. The electric conductivity and the viscosity were measured and the influence of the degree of hydrogen bonding in the supercooled liquid region analyzed. Hysteresis loops were detected in freezing-melting cycles and the effect of the length of the alkyl chain of the cation on the size of the loop analyzed, showing that longer chains lead to a narrowing of the supercooled region. The temperature dependence of the conductivity was studied in the Vogel-Fulcher-Tamman (VFT) framework and the fragility indices, the effective activation energies, and the Vogel temperatures obtained. A high-temperature Arrhenius analysis was also performed, and the activation energies of conductivity and viscosity were calculated, showing that these transport processes are

  7. Green synthesis of mesoporous molecular sieve incorporated monoliths using room temperature ionic liquid and deep eutectic solvents.

    Science.gov (United States)

    Zhang, Li-Shun; Zhao, Qing-Li; Li, Xin-Xin; Li, Xi-Xi; Huang, Yan-Ping; Liu, Zhao-Sheng

    2016-12-01

    A hybrid monolith incorporated with mesoporous molecular sieve MCM-41 of uniform pore structure and high surface area was prepared with binary green porogens in the first time. With a mixture of room temperature ionic liquids and deep eutectic solvents as porogens, MCM-41 was modified with 3-(trimethoxysilyl) propyl methacrylate (γ-MPS) and the resulting MCM-41-MPS was incorporated into poly (BMA-co-EDMA) monoliths covalently. Because of good dispersibility of MCM-41-MPS in the green solvent-based polymerization system, high permeability and homogeneity for the resultant hybrid monolithic columns was achieved. The MCM-41-MPS grafted monolith was characterized by scanning electron microscopy, energy dispersive spectrometer area scanning, transmission electron microscopy, FT-IR spectra and nitrogen adsorption tests. Chromatographic performance of MCM-41-MPS grafted monolith was characterized by separating small molecules in capillary electrochromatography, including phenol series, naphthyl substitutes, aniline series and alkyl benzenes. The maximum column efficiency of MCM-41-MPS grafted monolith reached 209,000 plates/m, which was twice higher than the corresponding MCM-41-MPS free monolith. Moreover, successful separation of non-steroidal anti-inflammatory drugs and polycyclic aromatic hydrocarbons demonstrated the capacity in broad-spectrum application of the MCM-41-MPS incorporated monolith. The results indicated that green synthesis using room temperature ionic liquid and deep eutectic solvents is an effective method to prepare molecular sieve-incorporated monolithic column. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Computationally Efficient Prediction of Ionic Liquid Properties

    DEFF Research Database (Denmark)

    Chaban, V. V.; Prezhdo, O. V.

    2014-01-01

    Due to fundamental differences, room-temperature ionic liquids (RTIL) are significantly more viscous than conventional molecular liquids and require long simulation times. At the same time, RTILs remain in the liquid state over a much broader temperature range than the ordinary liquids. We exploit...... the ability of RTILs to stay liquid at several hundred degrees Celsius and introduce a straightforward and computationally efficient method for predicting RTIL properties at ambient temperature. RTILs do not alter phase behavior at 600-800 K. Therefore, their properties can be smoothly extrapolated down...... to ambient temperatures. We numerically prove the validity of the proposed concept for density and ionic diffusion of four different RTILs. This simple method enhances the computational efficiency of the existing simulation approaches as applied to RTILs by more than an order of magnitude....

  9. Electrochemical measurements of mass transfer in RTILs (Room Temperature Ionic Liquids) medium under low frequency ultrasound irradiation; Mesures electrochimiques de transfert de matiere en milieu RTIL's (Room Temperature Ionic Liquids) sous irradiation ultrasonore basse frequence

    Energy Technology Data Exchange (ETDEWEB)

    Costa, C.; Hihn, J.Y.; Rebetez, M.; Doche, M.L. [Universite de Franche Comte - IUT Dept. Chimie, Institut UTINAM-UMR CNRS 6213, 25 - Montbeliard (France); Costa, C.; Bisel, I. [CEA Valrho, Dir. de l' Energie Nucleaire (DEN/DRCP/SCPS/LPCP), 30 - Marcoule (France); Moisy, Ph. [CEA Valrho, Dir. de l' Energie Nucleaire (DEN/DRCP/SCPS/LCA), 30 - Marcoule (France)

    2007-07-01

    The aim of this work is to measure the influence of ultrasounds on the mass transfer at the electrode. The electro diffusional method which consists to measure the limit diffusion current on the polarization curve i=f(E) of a reversible couple in diluted solution in the electrolyte. The used couple changes with the electrolytic medium: potassium ferro/ferricyanide in water, ferrocene/ferricinium for acetonitrile and for the ionic liquid 1-butyl-3-methyl-imidazolium bis(tri-fluoro-methyl-sulfonyl)imide [BuMIm][CF{sub 3}SO{sub 2}){sub 2}N]). The limit diffusion currents are converted into mass transfer coefficients and then into a dimensional Sherwood numbers to allow an easier comparison of the results between the different research teams participating to this study. Recent tests, carried out in partner laboratories (LCMI-UFC, LPCP-CEA and LCA-CEA) have demonstrated the interest of the use of power ultrasounds in Room Temperature Ionic Liquids (RTILs) but revealed too a lot of experimental difficulties. Nevertheless, it appears that the ultrasounds are an aging mode particularly adapted to the RTILs because the mass transfer to the electrode is there 5 times more efficient than in presence of an electrode turning at 4500 tr.min{sup -1}, while limiting their re-hydration. (O.M.)

  10. Fluctuating hydrodynamics for ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Lazaridis, Konstantinos [Department of Mathematics and Statistics, Washington State University, Pullman, 99163 (United States); Wickham, Logan [Department of Computer Science, Washington State University, Richland, 99354 (United States); Voulgarakis, Nikolaos, E-mail: n.voulgarakis@wsu.edu [Department of Mathematics and Statistics, Washington State University, Pullman, 99163 (United States)

    2017-04-25

    We present a mean-field fluctuating hydrodynamics (FHD) method for studying the structural and transport properties of ionic liquids in bulk and near electrified surfaces. The free energy of the system consists of two competing terms: (1) a Landau–Lifshitz functional that models the spontaneous separation of the ionic groups, and (2) the standard mean-field electrostatic interaction between the ions in the liquid. The numerical approach used to solve the resulting FHD-Poisson equations is very efficient and models thermal fluctuations with remarkable accuracy. Such density fluctuations are sufficiently strong to excite the experimentally observed spontaneous formation of liquid nano-domains. Statistical analysis of our simulations provides quantitative information about the properties of ionic liquids, such as the mixing quality, stability, and the size of the nano-domains. Our model, thus, can be adequately parameterized by directly comparing our prediction with experimental measurements and all-atom simulations. Conclusively, this work can serve as a practical mathematical tool for testing various theories and designing more efficient mixtures of ionic liquids. - Highlights: • A new fluctuating hydrodynamics method for ionic liquids. • Description of ionic liquid morphology in bulk and near electrified surfaces. • Direct comparison with experimental measurements.

  11. The distillation and volatility of ionic liquids

    Science.gov (United States)

    Earle, Martyn J.; Esperança, José M. S. S.; Gilea, Manuela A.; Canongia Lopes, José N.; Rebelo, Luís P. N.; Magee, Joseph W.; Seddon, Kenneth R.; Widegren, Jason A.

    2006-02-01

    It is widely believed that a defining characteristic of ionic liquids (or low-temperature molten salts) is that they exert no measurable vapour pressure, and hence cannot be distilled. Here we demonstrate that this is unfounded, and that many ionic liquids can be distilled at low pressure without decomposition. Ionic liquids represent matter solely composed of ions, and so are perceived as non-volatile substances. During the last decade, interest in the field of ionic liquids has burgeoned, producing a wealth of intellectual and technological challenges and opportunities for the production of new chemical and extractive processes, fuel cells and batteries, and new composite materials. Much of this potential is underpinned by their presumed involatility. This characteristic, however, can severely restrict the attainability of high purity levels for ionic liquids (when they contain poorly volatile components) in recycling schemes, as well as excluding their use in gas-phase processes. We anticipate that our demonstration that some selected families of commonly used aprotic ionic liquids can be distilled at 200-300°C and low pressure, with concomitant recovery of significant amounts of pure substance, will permit these currently excluded applications to be realized.

  12. Modeling electrokinetics in ionic liquids.

    Science.gov (United States)

    Wang, Chao; Bao, Jie; Pan, Wenxiao; Sun, Xin

    2017-07-01

    Using direct numerical simulations, we provide a thorough study regarding the electrokinetics of ionic liquids. In particular, modified Poisson-Nernst-Planck equations are solved to capture the crowding and overscreening effects characteristic of an ionic liquid. For modeling electrokinetic flows in an ionic liquid, the modified Poisson-Nernst-Planck equations are coupled with Navier-Stokes equations to study the coupling of ion transport, hydrodynamics, and electrostatic forces. Specifically, we consider the ion transport between two parallel charged surfaces, charging dynamics in a nanopore, capacitance of electric double-layer capacitors, electroosmotic flow in a nanochannel, electroconvective instability on a plane ion-selective surface, and electroconvective flow on a curved ion-selective surface. We also discuss how crowding and overscreening and their interplay affect the electrokinetic behaviors of ionic liquids in these application problems. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Ionic Liquid Epoxy Resin Monomers

    Science.gov (United States)

    Paley, Mark S. (Inventor)

    2013-01-01

    Ionic liquid epoxide monomers capable of reacting with cross-linking agents to form polymers with high tensile and adhesive strengths. Ionic liquid epoxide monomers comprising at least one bis(glycidyl) N-substituted nitrogen heterocyclic cation are made from nitrogen heterocycles corresponding to the bis(glycidyl) N-substituted nitrogen heterocyclic cations by a method involving a non-nucleophilic anion, an alkali metal cation, epichlorohydrin, and a strong base.

  14. Vibrational energy relaxation of a diatomic molecule in a room-temperature ionic liquid.

    Science.gov (United States)

    Shim, Youngseon; Kim, Hyung J

    2006-07-14

    Vibrational energy relaxation (VER) dynamics of a diatomic solute in ionic liquid 1-ethyl-3-methylimidazolium hexafluorophosphate (EMI(+)PF(6) (-)) are studied via equilibrium and nonequilibrium molecular dynamics simulations. The time scale for VER is found to decrease markedly with the increasing solute dipole moment, consonant with many previous studies in polar solvents. A detailed analysis of nonequilibrium results shows that for a dipolar solute, dissipation of an excess solute vibrational energy occurs almost exclusively via the Lennard-Jones interactions between the solute and solvent, while an oscillatory energy exchange between the two is mainly controlled by their electrostatic interactions. Regardless of the anharmonicity of the solute vibrational potential, VER becomes accelerated as the initial vibrational energy increases. This is attributed primarily to the enhancement in variations of the solvent force on the solute bond, induced by large-amplitude solute vibrations. One interesting finding is that if a time variable scaled with the initial excitation energy is employed, dissipation dynamics of the excess vibrational energy of the dipolar solute tend to show a universal behavior irrespective of its initial vibrational state. Comparison with water and acetonitrile shows that overall characteristics of VER in EMI(+)PF(6) (-) are similar to those in acetonitrile, while relaxation in water is much faster than the two. It is also found that the Landau-Teller theory predictions for VER time scale obtained via equilibrium simulations of the solvent force autocorrelation function are in reasonable agreement with the nonequilibrium results.

  15. Pressure-volume-temperature measurements of phosphonium-based ionic liquids and analysis with simple equations of state

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, F.A.M.M.; Costa, C.S.M.F.; Ferreira, C.E.; Bernardo, J.C.S. [Departamento de Engenharia Quimica, Faculdade de Ciencias e Tecnologia, Universidade de Coimbra, Polo II, Rua Silvio Lima, 3030-790 Coimbra (Portugal); Johnson, I. [Centre for Nano Science and Applied Thermodynamics, Department of Physics, St. Joseph' s college, Trichy 620 002 (India); Fonseca, I.M.A. [Departamento de Engenharia Quimica, Faculdade de Ciencias e Tecnologia, Universidade de Coimbra, Polo II, Rua Silvio Lima, 3030-790 Coimbra (Portugal); Ferreira, A.G.M., E-mail: abel@eq.uc.p [Departamento de Engenharia Quimica, Faculdade de Ciencias e Tecnologia, Universidade de Coimbra, Polo II, Rua Silvio Lima, 3030-790 Coimbra (Portugal)

    2011-06-15

    Research highlights: Density for trihexyltetradecylphosphonium ionic liquids with {+-} 0.5 kg.m{sup -3}. Goharshadi-Morsali-Abbaspour EoS gives good correlation and extrapolation of data. Sanchez-Lacombe EoS gives good correlation and reliable free volumes. The calculated thermomechanical coefficients are consistent with literature data. - Abstract: In spite of the great importance of the (P, V, T) data of phosphonium-based ionic liquids, only limited information on these data seems to be available in the open literature. In this work, we present the results for the density measurements of the trihexyltetradecylphosphonium chloride, [(C{sub 6}H{sub 13}){sub 3}P(C{sub 14}H{sub 29})][Cl] and trihexyltetradecylphosphonium dicyanamide, [(C{sub 6}H{sub 13}){sub 3}P(C{sub 14}H{sub 29})][N(CN{sub 2})] with an estimated uncertainty of {+-}0.5 kg . m{sup -3}. The ranges of temperature and pressure are T = (273.15 to 318.15) K and p = (0.1 to 25) MPa for [(C{sub 6}H{sub 13}){sub 3}P(C{sub 14}H{sub 29})][Cl] and T = (273.15 to 318.15) K and p = (0.1 to 35) MPa for [(C{sub 6}H{sub 13}){sub 3}P(C{sub 14}H{sub 29})][N(CN{sub 2})]. The high consistency of our data for [(C{sub 6}H{sub 13}){sub 3}P(C{sub 14}H{sub 29})][Cl] compared with those measured by other authors allowed all the experimental data for this IL to be combined and correlated using the Goharshadi-Morsali-Abbaspour equation of state over a wide range of temperature and pressure. From this equation, thermomechanical coefficients as the isothermal compressibility, thermal expansivity, thermal pressure, and internal pressure were calculated for the two ILs. The Sanchez-Lacombe equation of state was used also for (P, V, T) correlation and the estimation of the free volume in these phosphonium ionic liquids. Finally ionic volumes for trihexyltetradecylphosphonium cation and several anions available in the literature made possible the calculation of the free (hole) volume.

  16. TiO2 coated Si nanowire electrodes for electrochemical double layer capacitors in room temperature ionic liquid

    Science.gov (United States)

    Konstantinou, F.; Shougee, A.; Albrecht, T.; Fobelets, K.

    2017-10-01

    Three TiO2 deposition processes are used to coat the surface of Si nanowire array electrodes for electrochemical double layer capacitors in room temperature ionic liquid [Bmim][NTF2]. The fabrication processes are based on wet chemistry only and temperature treatments are kept below 450 °C. Successful TiO2 coatings are found to be those that are carried out at low pressure and with low TiO2 coverage to avoid nanowires breakage. The best TiO2 coated Si nanowire array electrode in [Bmim][NTF2] showed energy densities of 0.9 Wh·kg-1 and power densities of 2.2 kW·kg-1 with a nanowire length of ~10 µm.

  17. Liquid-Liquid Extraction in Systems Containing Butanol and Ionic Liquids – A Review

    National Research Council Canada - National Science Library

    Artur Kubiczek; Władysław Kamiński

    2017-01-01

    Room-temperature ionic liquids (RTILs) are a moderately new class of liquid substances that are characterized by a great variety of possible anion-cation combinations giving each of them different properties...

  18. Influence of temperature on the structure and dynamics of the [BMIM][PF(6)] ionic liquid/graphite interface.

    Science.gov (United States)

    Kislenko, Sergey A; Amirov, Ravil H; Samoylov, Igor S

    2010-10-07

    The influence of temperature on the structure and dynamics of the [BMIM][PF(6)] ionic liquid/graphite interface has been investigated by molecular dynamics simulations. The performed simulations cover a 100 K wide temperature interval, ranging from 300 K to 400 K. It was shown that the magnitudes of density peaks of anions in the vicinity of the surface decrease with increasing temperature while in the case of cations anomalous temperature behaviour of the density profile is observed: the magnitude of the second peak of cations increases with the increase of temperature. To characterize interface dynamics the local self-diffusion coefficients D(x) of ions in the normal direction to the surface and the residence time of ions in the first and second interfacial layer have been estimated. It was shown that the local self-diffusion coefficients in the vicinity of the surface correlate with the local ion density; the maxima of the function D(x)(x) for the cations (anions) coincide with the regions of reduced cation (anion) density and vice versa. Finally, the influence of temperature on the screening potential in the vicinity of a charged graphite surface has been studied. It was shown that the increase of temperature from 300 K to 400 K induces the decrease of the potential drop across the interface that implies the increase of the capacitance of the electrical double layer.

  19. Highly efficient extraction of phenolic compounds by use of magnetic room temperature ionic liquids for environmental remediation

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Ning [School of Chemical Engineering, Hefei University of Technology, Hefei, Anhui Province 230009 (China); Li, Min; Zhao, Lijie; Lu, Chengfei; Rooy, Sergio L. de [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Warner, Isiah M., E-mail: iwarner@lsu.edu [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States)

    2011-09-15

    Highlights: {yields} Novel separation technique based on the use of magnetic extraction. {yields} Using a magnetic room temperature ionic liquid for removal of hazardous phenols from contaminated soil samples. {yields} Inherently safer and cleaner technique demonstrated highest extraction capacity as compared with previous regular non-magnetic RTILs. {yields} Successfully remove highly hazardous pentachlorophenol from superfund site contaminated soil samples with extremely high extraction capacity. {yields} Contributions of our work focus primarily on remediation of contaminated soil and groundwater. - Abstract: A hydrophobic magnetic room temperature ionic liquid (MRTIL), trihexyltetradecylphosphonium tetrachloroferrate(III) ([3C{sub 6}PC{sub 14}][FeCl{sub 4}]), was synthesized from trihexyltetradecylphosphonium chloride and FeCl{sub 3}.6H{sub 2}O. This MRTIL was investigated as a possible separation agent for solvent extraction of phenolic compounds from aqueous solution. Due to its strong paramagnetism, [3C{sub 6}PC{sub 14}][FeCl{sub 4}] responds to an external neodymium magnet, which was employed in the design of a novel magnetic extraction technique. The conditions for extraction, including extraction time, volume ratio between MRTIL and aqueous phase, pH of aqueous solution, and structures of phenolic compounds were investigated and optimized. The magnetic extraction of phenols achieved equilibrium in 20 min and the phenolic compounds were found to have higher distribution ratios under acidic conditions. In addition, it was observed that phenols containing a greater number of chlorine or nitro substituents exhibited higher distribution ratios. For example, the distribution ratio of phenol (D{sub Ph}) was 107. In contrast, 3,5-dichlorophenol distribution ratio (D{sub 3,5-DCP}) had a much higher value of 6372 under identical extraction conditions. When compared with four selected traditional non-magnetic room temperature ionic liquids, our [3C{sub 6}PC{sub 14

  20. Water Contaminant Mitigation in Ionic Liquid Propellant

    Science.gov (United States)

    Conroy, David; Ziemer, John

    2009-01-01

    Appropriate system and operational requirements are needed in order to ensure mission success without unnecessary cost. Purity requirements applied to thruster propellants may flow down to materials and operations as well as the propellant preparation itself. Colloid electrospray thrusters function by applying a large potential to a room temperature liquid propellant (such as an ionic liquid), inducing formation of a Taylor cone. Ions and droplets are ejected from the Taylor cone and accelerated through a strong electric field. Electrospray thrusters are highly efficient, precise, scaleable, and demonstrate low thrust noise. Ionic liquid propellants have excellent properties for use as electrospray propellants, but can be hampered by impurities, owing to their solvent capabilities. Of foremost concern is the water content, which can result from exposure to atmosphere. Even hydrophobic ionic liquids have been shown to absorb water from the air. In order to mitigate the risks of bubble formation in feed systems caused by water content of the ionic liquid propellant, physical properties of the ionic liquid EMI-Im are analyzed. The effects of surface tension, material wetting, physisorption, and geometric details of the flow manifold and electrospray emitters are explored. Results are compared to laboratory test data.

  1. Lipid processing in ionic liquids

    DEFF Research Database (Denmark)

    Lue, Bena-Marie; Guo, Zheng; Xu, Xuebing

    2007-01-01

    Ionic liquids (ILs) have been touted as “green” alternatives to traditional molecular solvents and have many unique properties which make them extremely desirable substitutes. Among their most attractive properties are their lack of vapour pressure, broad liquid range, strong solvating power...

  2. Ionic liquids behave as dilute electrolyte solutions.

    Science.gov (United States)

    Gebbie, Matthew A; Valtiner, Markus; Banquy, Xavier; Fox, Eric T; Henderson, Wesley A; Israelachvili, Jacob N

    2013-06-11

    We combine direct surface force measurements with thermodynamic arguments to demonstrate that pure ionic liquids are expected to behave as dilute weak electrolyte solutions, with typical effective dissociated ion concentrations of less than 0.1% at room temperature. We performed equilibrium force-distance measurements across the common ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][NTf2]) using a surface forces apparatus with in situ electrochemical control and quantitatively modeled these measurements using the van der Waals and electrostatic double-layer forces of the Derjaguin-Landau-Verwey-Overbeek theory with an additive repulsive steric (entropic) ion-surface binding force. Our results indicate that ionic liquids screen charged surfaces through the formation of both bound (Stern) and diffuse electric double layers, where the diffuse double layer is comprised of effectively dissociated ionic liquid ions. Additionally, we used the energetics of thermally dissociating ions in a dielectric medium to quantitatively predict the equilibrium for the effective dissociation reaction of [C4mim][NTf2] ions, in excellent agreement with the measured Debye length. Our results clearly demonstrate that, outside of the bound double layer, most of the ions in [C4mim][NTf2] are not effectively dissociated and thus do not contribute to electrostatic screening. We also provide a general, molecular-scale framework for designing ionic liquids with significantly increased dissociated charge densities via judiciously balancing ion pair interactions with bulk dielectric properties. Our results clear up several inconsistencies that have hampered scientific progress in this important area and guide the rational design of unique, high-free-ion density ionic liquids and ionic liquid blends.

  3. TETRAALKYLPHOSPHONIUM POLYOXOMETALATES AS NOVEL IONIC LIQUIDS.

    Energy Technology Data Exchange (ETDEWEB)

    DIETZ,M.L.; RICKERT, P.G.; ANTONIO, M.R.; FIRESTONE, M.A.; WISHART, J.F.; SZREDER, T.

    2007-11-30

    The pairing of a Lindqvist or Keggin polyoxometalate (POM) anion with an appropriate tetraalkylphosphonium cation, [R{sub 3}R{prime}P]{sup +}, has been shown to yield an original family of ionic liquids (POM-ILs), among them salts liquid at or near ambient temperature. The physicochemical properties of several such 'inorganic liquids', in particular their thermal properties, suggests the possible application of these compounds as robust, thermally-stable solvents for liquid-liquid extraction. A preliminary evaluation of the potential of POM-ILs in this application is presented.

  4. Temperature regulated Brønsted acidic ionic liquid-catalyze esterification of oleic acid for biodiesel application

    Science.gov (United States)

    Rafiee, Ezzat; Mirnezami, Fakhrosadat

    2017-02-01

    By combining phosphotungstic acid (PW) and SO3H- functioned zwitterion, heteropoly anion-based Brønsted acidic ionic liquids (HPA-ILs) were successfully obtained. Scanning electron microscopy and energy dispersive X-ray spectroscopy were provided the morphology and composition of the prepared material. Catalytic performance and reusability of the catalysts were evaluated through an esterification reaction between oleic acid and methanol for production of biodiesel. Relationship between catalytic activities and acidity of the catalysts have been discussed by potentiometric titration. The results showed that HPA-ILs had good activity and reusability. HPA-ILs dissolved in the reaction mixture during the reaction process and could be precipitated and separated from products at lower temperature.

  5. Electrochemistry of room temperature protic ionic liquids: a critical assessment for use as electrolytes in electrochemical applications.

    Science.gov (United States)

    Lu, Xunyu; Burrell, Geoff; Separovic, Frances; Zhao, Chuan

    2012-08-02

    Ten room temperature protic ionic liquids (RTPILs) have been prepared from low-molecular-weight Brønsted acids and amines with high purity and minimal water content, and their electrochemical characteristics determined using cyclic, microelectrode, and rotating disk electrode voltammetries. Potential windows of the 10 RTPILs were established at glassy carbon, gold, and platinum electrodes, where the largest potential window is generally observed with glassy carbon electrodes. The two IUPAC recommended internal potential reference systems, ferrocene/ferrocenium and cobaltocenium/cobaltocene, were determined for the 10 RTPILs, and their merits as well as limitations are discussed. Other electrochemical properties such as mass transport and double layer capacitances were also investigated. The potential applications of these RTPILs as electrolytes for electrochemical energy devices were discussed, and two novel applications using PILs for metal deposition and water electrolysis were demonstrated.

  6. Charge effect on the diffusion coefficient and the bimolecular reaction rate of diiodide anion radical in room temperature ionic liquids.

    Science.gov (United States)

    Nishiyama, Yoshio; Terazima, Masahide; Kimura, Yoshifumi

    2009-04-16

    The diffusion coefficients of diiodide anion radical, I(2)(-), in room temperature ionic liquids (RTILs) were determined by the transient grating (TG) method using the photochemical reaction of iodide. The diffusion coefficients we obtained were larger in RTILs than the theoretical predictions by the Stokes-Einstein relation, whereas both values are similar in conventional solvents. By comparison with the diffusion coefficients of neutral molecules, it was suggested that the Coulomb interaction between I(2)(-) and constituent ions of RTILs strongly affects the diffusion coefficients. The bimolecular reaction rates between I(2)(-) were calculated by the Debye-Smoluchowski equation using the experimentally determined diffusion coefficients. These calculated reaction rate were much smaller than the experimentally determined rates (Takahashi, K.; et al. J. Phys. Chem. B 2007, 111, 4807), indicating the charge screening effect of RTILs.

  7. Molecular Design of Polymerized Ionic Liquids

    Science.gov (United States)

    Sanoja, Gabriel Eduardo

    Polymerized ionic liquids are an emerging class of functional materials with ionic liquid moieties covalently attached to a polymer backbone. As such, they synergistically combine the structural hierarchy of polymers with the versatile physicochemical properties of ionic liquids. Unlike other ion-containing polymers that are typically constrained to high glass transition temperatures, polymerized ionic liquids can exhibit low glass transition temperatures due to weak electrostatic interactions even at high charge fractions. Promising applications relevant to electrochemical energy conversion and CO2 capture and sequestration have been demonstrated for polymerized ionic liquids, but a molecular design strategy that allows for elucidation of their structure-property relationships is yet to be developed. A combination of anionic polymerization, click chemistry, and ion metathesis allows for fine and independent control over polymer properties including the number of repeat units, fraction of ionic liquid moieties, composition, and architecture. This strategy has been exploited to elucidate the effect of lamellar domain spacing on the ionic conductivity of block copolymers based on hydrated protic polymerized ionic liquids. The conductivity relationship demonstrated in this study suggests that a mechanically robust material can be designed without compromising its ability to transport ions. The vast set of ion pair combinations in polymerized liquids provides a unique opportunity to develop functional materials where properties can be controlled with subtle changes in molecular structure via ion metathesis. We illustrate the case of a polymerized ionic liquid that combines the low toxicity and macromolecular dimensions of poly(ethylene glycol) with the magnetic functionality of ion pairs containing iron(III). This material can yield novel theranostic agents with controlled residence time within the human body, and paramagnetic functionality to enhance 1H nuclei

  8. Preconcentration and trace determination of cadmium in spinach and various water samples by temperature-controlled ionic liquid dispersive liquid phase microextraction.

    Science.gov (United States)

    Rahnama, Reyhaneh; Mansoursamaei, Nazanin; Jamali, Mohammad Reza

    2014-01-01

    A sensitive and selective method for the preconcentration and separation of sub µg L-1 levels of cadmium ions in aqueous solutions with high salt contents is described. The developed method is based on temperature-controlled ionic liquid dispersive liquid phase microextraction of cadmium using the 1-hexyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide (ionic liquid (IL)) as an extractant followed by flame atomic absorption spectrometry determination. The extraction of cadmium ions from the aqueous solution into the fine droplets of IL was performed with dithizone as the chelating agent. Some predominant factors affecting the preconcentration of cadmium ions were evaluated and optimized. Under the optimum conditions, the calibration graph was linear over the concentration range from 0.6-20.0 µg L-1 of cadmium and the limit of detection (LOD) was 0.2 µg L-1. The enrichment factor was found to be 25. The developed method was successfully applied to the determination of cadmium in spinach and water samples.

  9. Use of ionic liquids as coordination ligands for organometallic catalysts

    Science.gov (United States)

    Li, Zaiwei [Moreno Valley, CA; Tang, Yongchun [Walnut, CA; Cheng,; Jihong, [Arcadia, CA

    2009-11-10

    Aspects of the present invention relate to compositions and methods for the use of ionic liquids with dissolved metal compounds as catalysts for a variety of chemical reactions. Ionic liquids are salts that generally are liquids at room temperature, and are capable of dissolving a many types of compounds that are relatively insoluble in aqueous or organic solvent systems. Specifically, ionic liquids may dissolve metal compounds to produce homogeneous and heterogeneous organometallic catalysts. One industrially-important chemical reaction that may be catalyzed by metal-containing ionic liquid catalysts is the conversion of methane to methanol.

  10. Thermo-responsive poly(ionic liquid) valves for microfluidic devices

    OpenAIRE

    Tudor, Alexandru; Saez, Janire; Florea, Larisa; Benito-Lopez, Fernando; Diamond, Dermot

    2016-01-01

    Poly(ionic liquid)s (PIL) are a class of ionic liquids that feature polymerizable groups in the cation, the anion or both. They retain most of the properties present in ionic liquids, including ionic conductivity, low vapour pressure and tunable physico-chemical properties. Several phosphonium ionic liquids have been shown to possess a lower critical solution temperature, making them suitable materials for the synthesis of temperature-responsive smart materials.1,2 Herein, we present the synt...

  11. Absorption and oxidation of no in ionic liquids

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention concerns the absorption and in situ oxidation of nitric oxide (NO) in the presence of water and oxygen in ionic liquid compositions at ambient temperature.......The present invention concerns the absorption and in situ oxidation of nitric oxide (NO) in the presence of water and oxygen in ionic liquid compositions at ambient temperature....

  12. Ionic Liquids in Lithium-Ion Batteries.

    Science.gov (United States)

    Balducci, Andrea

    2017-04-01

    Lithium-ion batteries are among the most widespread energy storage devices in our society. In order to introduce these devices in new key applications such as transportation, however, their safety and their operative temperature range need to be significantly improved. These improvements can be obtained only by developing new electrolytes. Ionic liquids are presently considered among the most attractive electrolytes for the development of advanced and safer lithium-ion batteries. In this manuscript, the use of various types of ionic liquids, e.g. aprotic and protic, in lithium-ion batteries is considered. The advantages and the limits associated to the use of these innovative electrolytes are critically analysed.

  13. Ionic-liquid based electrochemical ethylene sensor

    NARCIS (Netherlands)

    Zevenbergen, M.A.G.; Wouters, D.; Dam, V.-A.T.; Brongersma, S.H.; Crego-Calama, M.

    2011-01-01

    We present an electrochemical ethylene sensor that exploits a thin ionic-liquid (IL) layer as electrolyte. ILs are fluids that completely consist of ions at room temperature and have emerged as extremely promising electrolytes for the following reasons: first, the vapor pressure is practically

  14. Catalytic Alkene Metathesis in Ionic Liquids

    Science.gov (United States)

    Fischmeister, Cédric

    Olefin metathesis has found a tremendous number of application in the past 25 years. Immobilisation of olefin metathesis (pre)catalysts in room temperature ionic liquids (RTILs) offers the opportunity to recover and reuse the catalyst and also to reduce the level of ruthenium (Ru) contaminants in the products.

  15. Diglycolamide-functionalized calix[4]arenes showing unusual complexation of actinide ions in room temperature ionic liquids: role of ligand structure, raiolytic stability, emission spectroscopy, and thermodynamic studies

    NARCIS (Netherlands)

    Mohapatra, Prasanta K.; Sengupta, A.; Iqbal, M.; Huskens, Jurriaan; Verboom, Willem

    2013-01-01

    Diglycolamide-functionalized calix[4]arenes (C4DGAs) with varying structural modifications were evaluated for actinide complexation from their extraction behavior toward actinide ions such as UO22+, Pu4+, PuO22+, and Am3+ in the room temperature ionic liquid (RTIL) 1-n-octyl-3-methylimidazolium

  16. Hydrogen bonding in ionic liquids.

    Science.gov (United States)

    Hunt, Patricia A; Ashworth, Claire R; Matthews, Richard P

    2015-03-07

    Ionic liquids (IL) and hydrogen bonding (H-bonding) are two diverse fields for which there is a developing recognition of significant overlap. Doubly ionic H-bonds occur when a H-bond forms between a cation and anion, and are a key feature of ILs. Doubly ionic H-bonds represent a wide area of H-bonding which has yet to be fully recognised, characterised or explored. H-bonds in ILs (both protic and aprotic) are bifurcated and chelating, and unlike many molecular liquids a significant variety of distinct H-bonds are formed between different types and numbers of donor and acceptor sites within a given IL. Traditional more neutral H-bonds can also be formed in functionalised ILs, adding a further level of complexity. Ab initio computed parameters; association energies, partial charges, density descriptors as encompassed by the QTAIM methodology (ρBCP), qualitative molecular orbital theory and NBO analysis provide established and robust mechanisms for understanding and interpreting traditional neutral and ionic H-bonds. In this review the applicability and extension of these parameters to describe and quantify the doubly ionic H-bond has been explored. Estimating the H-bonding energy is difficult because at a fundamental level the H-bond and ionic interaction are coupled. The NBO and QTAIM methodologies, unlike the total energy, are local descriptors and therefore can be used to directly compare neutral, ionic and doubly ionic H-bonds. The charged nature of the ions influences the ionic characteristics of the H-bond and vice versa, in addition the close association of the ions leads to enhanced orbital overlap and covalent contributions. The charge on the ions raises the energy of the Ylp and lowers the energy of the X-H σ* NBOs resulting in greater charge transfer, strengthening the H-bond. Using this range of parameters and comparing doubly ionic H-bonds to more traditional neutral and ionic H-bonds it is clear that doubly ionic H-bonds cover the full range of weak

  17. Ionic liquid-tolerant cellulase enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Gladden, John; Park, Joshua; Singer, Steven; Simmons, Blake; Sale, Ken

    2017-10-31

    The present invention provides ionic liquid-tolerant cellulases and method of producing and using such cellulases. The cellulases of the invention are useful in saccharification reactions using ionic liquid treated biomass.

  18. Ionic and Molecular Liquids

    DEFF Research Database (Denmark)

    Chaban, Vitaly V.; Prezhdo, Oleg

    2013-01-01

    applications of RTILs in combination with molecular liquids, concentrating on three significant areas: (1) the use of molecular liquids to decrease the viscosity of RTILs; (2) the role of RTIL micelle formation in water and organic solvents; and (3) the ability of RTILs to adsorb pollutant gases. Current...

  19. Nanoparticle enhanced ionic liquid heat transfer fluids

    Science.gov (United States)

    Fox, Elise B.; Visser, Ann E.; Bridges, Nicholas J.; Gray, Joshua R.; Garcia-Diaz, Brenda L.

    2014-08-12

    A heat transfer fluid created from nanoparticles that are dispersed into an ionic liquid is provided. Small volumes of nanoparticles are created from e.g., metals or metal oxides and/or alloys of such materials are dispersed into ionic liquids to create a heat transfer fluid. The nanoparticles can be dispersed directly into the ionic liquid during nanoparticle formation or the nanoparticles can be formed and then, in a subsequent step, dispersed into the ionic liquid using e.g., agitation.

  20. Ionic liquid-nanoparticle hybrid electrolytes

    KAUST Repository

    Lu, Yingying

    2012-01-01

    We investigate physical and electrochemical properties of a family of organic-inorganic hybrid electrolytes based on the ionic liquid 1-methyl-3-propylimidazolium bis(trifluoromethanesulfone) imide covalently tethered to silica nanoparticles (SiO 2-IL-TFSI). The ionic conductivity exhibits a pronounced maximum versus LiTFSI composition, and in mixtures containing 13.4 wt% LiTFSI, the room-temperature ionic conductivity is enhanced by over 3 orders of magnitude relative to either of the mixture components, without compromising lithium transference number. The SiO 2-IL-TFSI/LiTFSI hybrid electrolytes are thermally stable up to 400°C and exhibit tunable mechanical properties and attractive (4.25V) electrochemical stability in the presence of metallic lithium. We explain these observations in terms of ionic coupling between counterion species in the mobile and immobile (particle-tethered) phases of the electrolytes. © 2012 The Royal Society of Chemistry.

  1. CPE OF URANIUM (VI USING IONIC LIQUID

    Directory of Open Access Journals (Sweden)

    SANAA NAÏT-TAHAR

    2016-07-01

    Full Text Available Cloud point extraction (CPE was used to extract uranium (VI from an aqueous solution in acetate media. The methodology used is based on the formation of uranyl-ionic liquid (I complexes and uranyl-D2EHPA soluble in a micellar phase of non-ionic surfactant (Triton X-100. The uranium (VI complexes are then extracted into the surfactant-rich phase at ambient temperature. The ionic liquid (IL used as a chelating agent was synthesized and characterized in this study. It is composed of N-butyl N’-triethoxy methyl imidazolium cation and diethylhexylphosphate (D2EHPA-H as anion. The effect of the IL on the extraction efficiency was studied in presence and in absence of IL’s cation in acetate medium.

  2. VOC and HAP recovery using ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Michael R. Milota : Kaichang Li

    2007-05-29

    During the manufacture of wood composites, paper, and to a lesser extent, lumber, large amounts of volatile organic compounds (VOCs) such as terpenes, formaldehyde, and methanol are emitted to air. Some of these compounds are hazardous air pollutants (HAPs). The air pollutants produced in the forest products industry are difficult to manage because the concentrations are very low. Presently, regenerative thermal oxidizers (RTOs and RCOs) are commonly used for the destruction of VOCs and HAPs. RTOs consume large amounts of natural gas to heat air and moisture. The combustion of natural gas generates increased CO2 and NOx, which have negative implications for global warming and air quality. The aforementioned problems are addressed by an absorption system containing a room-temperature ionic liquid (RTIL) as an absorbent. RTILs are salts, but are in liquid states at room temperature. RTILs, an emerging technology, are receiving much attention as replacements for organic solvents in industrial processes with significant cost and environmental benefits. Some of these processes include organic synthesis, extraction, and metal deposition. RTILs would be excellent absorbents for exhausts from wood products facilities because of their unique properties: no measurable vapor pressure, high solubility of wide range of organic compounds, thermal stability to 200°C (almost 400°F), and immisciblity with water. Room temperature ionic liquids were tested as possible absorbents. Four were imidizolium-based and were eight phosphonium-based. The imidizolium-based ionic liquids proved to be unstable at the conditions tested and in the presence of water. The phosphonium-based ionic liquids were stable. Most were good absorbents; however, cleaning the contaminates from the ionic liquids was problematic. This was overcome with a higher temperature (120°C) than originally proposed and a very low pressure (1 kPa. Absorption trials were conducted with tetradecy

  3. Ultrafast relaxation and reaction of diiodide anion after photodissociation of triiodide in room-temperature ionic liquids.

    Science.gov (United States)

    Nishiyama, Yoshio; Terazima, Masahide; Kimura, Yoshifumi

    2012-08-02

    Vibrational dephasing, vibrational relaxation, and rotational relaxation of diiodide (I(2)(-)) after photodissociation of triiodide (I(3)(-)) in room-temperature ionic liquids (RTILs) were investigated by ultrafast transient absorption spectroscopy. The vibrational energy relaxation (VER) rate of I(2)(-) produced by the photodissociation reaction of I(3)(-) was determined from the spectral profile of the transient absorption. The rates in RTILs were slightly slower than those in conventional liquids. On the other hand, the coherent vibration of I(2)(-) was not observed in RTILs, and the vibrational dephasing of the photoproduced I(2)(-) was accelerated. This was explained by the interaction between I(2)(-) and I consisting of a caged contact pair in RTILs. The orientational relaxation time of I(2)(-) determined by the transient absorption anisotropy was much longer in RTILs than in conventional liquids due to their high viscosities although the relaxation time was shorter than the prediction from the Stokes-Einstein-Debye (SED) theory. The deviation from the SED prediction was interpreted by the frequency dependence of the shear stress acting on the molecule. The dynamics of I(2)(-) in 1-butyl-3-methylimidazolium iodide ([BMIm]I) were quite different from those in other conventional RTILs: the coherent vibration of I(2)(-) was observed for the time profile of the transient absorption and the initial value of the anisotropy was reduced to 0.31 from 0.36 in conventional RTILs. These results suggest that an ultrafast reaction between the photofragment I and the solvent I(-) may occur during the photodissociation process of I(3)(-). The anomaly in the ground state coherent vibration and steady state Raman spectrum of I(3)(-) also suggest the possibility that I(3)(-) and I(-) can be located in vicinity and interact strongly with each other in [BMIm]I.

  4. Behavior of hydrophobic ionic liquids as liquid membranes on phenol removal: Experimental study and optimization

    CERN Document Server

    Ng, Y S; Hashim, M A

    2014-01-01

    Room temperature ionic liquids show potential as an alternative to conventional organic membrane solvents mainly due to their properties of low vapor pressure, low volatility and they are often stable. In the present work, the technical feasibilities of room temperature ionic liquids as bulk liquid membranes for phenol removal were investigated experimentally. Three ionic liquids with high hydrophobicity were used and their phenol removal efficiency, membrane stability and membrane loss were studied. Besides that, the effects of several parameters, namely feed phase pH, feed concentration, NaOH concentration and stirring speeds on the performance of best ionic liquid membrane were also evaluated. Lastly, an optimization study on bulk ionic liquid membrane was conducted and the maximum phenol removal efficiency was compared with the organic liquid membranes. The preliminary study shows that high phenol extraction and stripping efficiencies of 96.21% and 98.10%, respectively can be achieved by ionic liquid memb...

  5. Hydrogen production from glucose in ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Assenbaum, D.W.; Taccardi, N.; Berger, M.E.M.; Boesmann, A.; Enzenberger, F.; Woelfel, R.; Wasserscheid, P. [Erlangen-Nuernberg Univ. (Germany). Lehrstuhl fuer chemische Reaktionstechnik

    2010-07-01

    technologies suffer from the fact that the overall reaction rates are often restricted by mass and heat transport problems. Lastly, there are severe limitations concerning the feedstock selection as for some important substrates, such as e.g. glucose, the process can only be operated in very diluted systems to avoid rapid tar formation [22,23,24]. In this contribution we describe for the first time a catalytic reaction system producing hydrogen from glucose in astonishingly high selectivities using a single reaction step under very mild conditions. The catalytic reaction system is characterized by its homogeneous nature and comprises a Ru-complex catalyst dissolved and stabilized in an ionic liquid medium. Ionic liquids are salts of melting points below 100 C [25]. These liquid materials have attracted much interest in the last decade as solvents for catalytic reactions [26] and separation technologies (extraction, distillation) [27,28,29,30,31,32]. Besides, these liquids have found industrial applications as process fluids for mechanic [33] and electrochemical applications [34]. Finally, from the pioneering work of Rogers and co-workers, it is known that ionic liquids are able to dissolve significant amounts of water-insoluble biopolymers (such as e.g. cellulose and chitin)[35] and even complex biopolymer mixtures, such as e.g. wood, have been completely dissolved in some ionic liquids [36]. In our specific application, the role of the ionic liquid is threefold: a) the ionic liquid dissolves the carbohydrate starting material thus expanding the range of applicable carbohydrate to water insoluble polymers; b) the ionic liquid provides a medium to dissolve and stabilize the catalyst; c) the ionic liquid dissolves hydrogen at a very low level, so inhibiting any possible collateral hydrogen-consuming process (detailed investigation of the hydrogen solubility in ionic liquids have been reported by e.g. Brennecke and coworkers [37]). (orig.)

  6. Selective determination of inorganic cobalt in nutritional supplements by ultrasound-assisted temperature-controlled ionic liquid dispersive liquid phase microextraction and electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Berton, Paula; Martinis, Estefania M. [Analytical Chemistry Research and Development Group (QUIANID), (LISAMEN-CCT-CONICET-Mendoza), Av. Ruiz Leal S/N Parque General San Martin, M 5502 IRA Mendoza (Argentina); Martinez, Luis D. [INQUISAL-CONICET, Departamento de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, San Luis (Argentina); Wuilloud, Rodolfo G., E-mail: rwuilloud@mendoza-conicet.gob.ar [Analytical Chemistry Research and Development Group (QUIANID), (LISAMEN-CCT-CONICET-Mendoza), Av. Ruiz Leal S/N Parque General San Martin, M 5502 IRA Mendoza (Argentina); Instituto de Ciencias Basicas, Universidad Nacional de Cuyo, Mendoza (Argentina)

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer Synergy of ultrasound energy and TILDLME technique for improved metal extraction. Black-Right-Pointing-Pointer Highly selective determination of inorganic Co species at trace levels. Black-Right-Pointing-Pointer Speciation analysis of Co in several nutritional supplements with highly complex matrices. Black-Right-Pointing-Pointer Development of an environmentally friendly microextraction technique with minimal waste production and sample consumption. - Abstract: In the present work, a simple and rapid analytical method based on application of ionic liquids (ILs) for inorganic Co(II) species (iCo) microextraction in a variety of nutrient supplements was developed. Inorganic Co was initially chelated with 1-nitroso-2-naphtol (1N2N) reagent followed by a modern technique named ultrasound-assisted temperature-controlled ionic liquid dispersive liquid phase microextraction (USA-TILDLME). The extraction was performed with 1-hexyl-3-methylimidazolium hexafluorophosphate [C{sub 6}mim][PF{sub 6}] with the aid of ultrasound to improve iCo recovery. Finally, the iCo-enriched IL phase was solubilized in methanol and directly injected into an electrothermal atomic absorption spectrometer (ETAAS). Several parameters that could influence iCo microextraction and detection were carefully studied. Since the main difficulty in these samples is caused by high concentrations of potential interfering ions, different approaches were evaluated to eliminate interferences. The limit of detection (LOD) was 5.4 ng L{sup -1}, while the relative standard deviation (RSD) was 4.7% (at 0.5 {mu}g L{sup -1} Co level and n = 10), calculated from the peak height of absorbance signals. Selective microextraction of iCo species was achieved only by controlling the pH value during the procedure. The method was thus successfully applied for determination of iCo species in nutritional supplements.

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

    Science.gov (United States)

    Goodrich, Brett F; de la Fuente, Juan C; Gurkan, Burcu E; Lopez, Zulema K; Price, Erica A; Huang, Yong; Brennecke, Joan F

    2011-07-28

    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. The most important result of this study is that the viscosity of [P(66614)][Pro] only increased by a factor of 2 when fully complexed with 1 bar of CO(2) at room temperature. This is in stark contrast to the other chemically reacted ILs investigated here and all other amino acid-based ILs reported in the literature, which dramatically increase in viscosity, typically by 2 orders of magnitude, when complexed with CO(2). The unique behavior of [P(66614)][Pro] is likely due to its ring structure, which limits the number and availability of hydrogen atoms that can participate in a hydrogen bonding network. We found that water can be used to further reduce the viscosity of the CO(2)-complexed IL, while only slightly decreasing the CO(2) capacity. Finally, from temperature-dependent isotherms, we estimate a heat of absorption of -63 kJ/mol of CO(2) for the 1:1 reaction of CO(2) with [P(66614)][Pro], when we use the two-reaction model. © 2011 American Chemical Society

  8. Sensitive determination of cadmium in water samples by room temperature ionic liquid-based preconcentration and electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Martinis, Estefania M. [Laboratory of Environmental Research and Services of Mendoza (LISAMEN), (CCT - CONICET - Mendoza), Av. Ruiz Leal S/N Parque General San Martin, C.C. 131, M 5502 IRA Mendoza (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Olsina, Roberto A. [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Departamento de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis (Argentina); Altamirano, Jorgelina C. [Laboratory of Environmental Research and Services of Mendoza (LISAMEN), (CCT - CONICET - Mendoza), Av. Ruiz Leal S/N Parque General San Martin, C.C. 131, M 5502 IRA Mendoza (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Instituto de Ciencias Basicas, Universidad Nacional de Cuyo, Mendoza (Argentina); Wuilloud, Rodolfo G. [Laboratory of Environmental Research and Services of Mendoza (LISAMEN), (CCT - CONICET - Mendoza), Av. Ruiz Leal S/N Parque General San Martin, C.C. 131, M 5502 IRA Mendoza (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Instituto de Ciencias Basicas, Universidad Nacional de Cuyo, Mendoza (Argentina)], E-mail: rwuilloud@mendoza-conicet.gov.ar

    2008-10-17

    A sensitive preconcentration methodology for Cd determination at trace levels in water samples was developed in this work. 1-Butyl-3-methylimidazolium hexafluorophosphate ([C{sub 4}MIM][PF{sub 6}]) room temperature ionic liquid (RTIL) was successfully used for Cd preconcentration, as cadmium-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol complex [Cd-5-Br-PADAP]. Subsequently, Cd was back-extracted from the RTIL phase with 500 {mu}L of 0.5 mol L{sup -1} nitric acid and determined by electrothermal atomic absorption spectrometry (ETAAS). A preconcentration factor of 40 was achieved with 20 mL of sample. The limit of detection (LOD) obtained under optimum conditions was 3 ng L{sup -1} and the relative standard deviation (R.S.D.) for 10 replicates at 1 {mu}g L{sup -1} Cd{sup 2+} concentration level was 3.5%, calculated at peak heights. The calibration graph was linear from concentration levels near the detection limits up to at least 5 {mu}g L{sup -1}. A correlation coefficient of 0.9997 was achieved. Validation of the methodology was performed by standard addition method and analysis of certified reference material (CRM). The method was successfully applied to the determination of Cd in river and tap water samples.

  9. A study of chemical modifications of a Nafion membrane by incorporation of different room temperature ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Martinez de Yuso, M.V.; Rodriguez-Castellon, E. [Departamento de Quimica Inorganica, Facultad de Ciencias, Universidad de Malaga (Spain); Neves, L.A.; Coelhoso, I.M.; Crespo, J.G. [REQUIMTE/CQFB, Departamento de Quimica, Universidade Nova de Lisboa, Caparica (Portugal); Benavente, J. [Departamento de Fisica Aplicada I, Facultad de Ciencias, Universidad de Malaga (Spain)

    2012-08-15

    Surface and bulk chemical changes in a Nafion membrane as a result of room temperature ionic liquids (RTILs) incorporation were determined by X-ray photoelectron spectroscopy (XPS) and elemental analysis, respectively. RTILs with different physicochemical properties were selected. Two imidazolium based RTIL-cations (1-octyl-3-methylimidazolium and 1-butyl-3-methylimidazolium) were used to detect the effect of cation size on membrane modification, while the effect of the RTIL hydrophilic/hydrophobic character was also considered by choosing different anions. Angle resolved XPS measurements (ARXPS) were carried out varying the angle of analysis between 15 and 75 to get elemental information on the Nafion/RTIL-modified membranes interactions for a deepness of around 10 nm. Moreover, changes in the RTIL-modified membranes associated to thermal effect were also considered by analyzing the samples after their heating at 120 C for 24 h. Agreement between both chemical techniques, bulk and destructive elemental analysis and surface and non-destructive XPS, were obtained. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Nanoscale Ionic Liquids

    Science.gov (United States)

    2006-11-01

    management applications, electrolytes for high-temperature fuel cells/batteries, ferrofluids for actuators, compliant electrodes, zero VOC inks for...high- temperature fuel cells/batteries, zero VOC inks for microfabrication, compliant electrodes, ferrofluids for actuators or high refractive index...40,) [1] carbon nanotubes [9] and metals [10]. Since y-Fe 20 3 is magnetic, solvent- less ferrofluids are now possible. The ZnO fluids combine fluidity

  11. High CO{sub 2} solubility in ionic liquids and a tetraalkylammonium-based poly(ionic liquid)

    Energy Technology Data Exchange (ETDEWEB)

    Supasitmongkol, S.; Styring, P. [University of Sheffield, Sheffield (United Kingdom)

    2010-12-15

    Carbon dioxide (CO{sub 2}) absorption in several imidazolium-based ionic liquids (ILs), pyridinium-based ionic liquids and a tetraalkylammonium-based poly(ionic liquid) (PIL), poly((p-vinylbenzyl) trimethylammonium hexafluorophosphate) P((VBTMA)(PF6)), was studied. The trend of CO{sub 2} solubility in all of the ILs increases dramatically with decreasing absorption temperature. Based on the same bis(triflamide) (Tf2N) anion, imidazolium, pyridinium and trihexyltetradecylphosphonium-based ionic liquids all show relatively similar CO{sub 2} solubilities, which were higher than for the ES anion. The highest CO{sub 2} absorption was found in a poly(ionic liquid) P((VBTMA)(PF6)); however, the monomer also showed higher CO{sub 2} capacity than the other ionic liquids. The poly(ionic liquid) is remarkable in that it can adsorb 77% of its body weight of CO{sub 2} with a selectivity over nitrogen of 70:1. The absorbed CO{sub 2} gas can be readily desorbed from ionic liquids and poly(ionic liquid) and the selectivity for CO{sub 2} over N{sub 2} was consistent over repeated cycles. The materials can be reused several times for consecutive sorption/desorption cycles, without loss of performance in a large-scale reactor and therefore represent serious candidates for use in commercial adsorbers.

  12. Correlation between ion diffusional motion and ionic conductivity for different electrolytes based on ionic liquid.

    Science.gov (United States)

    Kaur, Dilraj Preet; Yamada, K; Park, Jin-Soo; Sekhon, S S

    2009-04-23

    Room temperature ionic liquid 2,3-dimethyl-1-hexylimidazolium bis(trifluoromethane sulfonyl)imide (DMHxImTFSI) has been synthesized and used in the preparation of polymer gel electrolytes containing polymethylmethacrylate and propylene carbonate (PC). The onset of ion diffusional motion has been studied by (1)H and (19)F NMR spectroscopy and the results obtained for ionic liquid, liquid electrolytes, and polymer gel electrolytes have been correlated with the ionic conductivity results for these electrolytes in the 100-400 K temperature range. The temperature at which (1)H and (19)F NMR lines show motional narrowing and hence ion diffusional motion starts has been found to be closely related to the temperature at which a large increase in ionic conductivity has been observed for these electrolytes. Polymer gel electrolytes have high ionic conductivity over a wide range of temperatures. Thermogravimetric analysis/differential scanning calorimetry studies show that the ionic liquid (DMHxImTFSI) used in the present study is thermally stable up to 400 degrees C, whereas the addition of PC lowers the thermal stability of polymer gel electrolytes containing the ionic liquid. Different electrolytes have been observed to show high ionic conductivity in different range of temperatures, which can be helpful in the design of polymer gel electrolytes for specific applications.

  13. Long range electrostatic forces in ionic liquids.

    Science.gov (United States)

    Gebbie, Matthew A; Smith, Alexander M; Dobbs, Howard A; Lee, Alpha A; Warr, Gregory G; Banquy, Xavier; Valtiner, Markus; Rutland, Mark W; Israelachvili, Jacob N; Perkin, Susan; Atkin, Rob

    2017-01-19

    Ionic liquids are pure salts that are liquid under ambient conditions. As liquids composed solely of ions, the scientific consensus has been that ionic liquids have exceedingly high ionic strengths and thus very short Debye screening lengths. However, several recent experiments from laboratories around the world have reported data for the approach of two surfaces separated by ionic liquids which revealed remarkable long range forces that appear to be electrostatic in origin. Evidence has accumulated demonstrating long range surface forces for several different combinations of ionic liquids and electrically charged surfaces, as well as for concentrated mixtures of inorganic salts in solvent. The original interpretation of these forces, that ionic liquids could be envisioned as "dilute electrolytes," was controversial, and the origin of long range forces in ionic liquids remains the subject of discussion. Here we seek to collate and examine the evidence for long range surface forces in ionic liquids, identify key outstanding questions, and explore possible mechanisms underlying the origin of these long range forces. Long range surface forces in ionic liquids and other highly concentrated electrolytes hold diverse implications from designing ionic liquids for energy storage applications to rationalizing electrostatic correlations in biological self-assembly.

  14. Influence of Hydroxyl Group Position and Temperature on Thermophysical Properties of Tetraalkylammonium Hydroxide Ionic Liquids with Alcohols

    Science.gov (United States)

    Attri, Pankaj; Baik, Ku Youn.; Venkatesu, Pannuru; Kim, In Tae; Choi, Eun Ha

    2014-01-01

    In this work, we have explored the thermophysical properties of tetraalkylammonium hydroxide ionic liquids (ILs) such as tetrapropylammonium hydroxide (TPAH) and tetrabutylammonium hydroxide (TBAH) with isomers of butanol (1-butanol, 2-butanol and 2-methyl-2-propanol) within the temperature range 293.15–313.15 K, with interval of 5 K and over the varied concentration range of ILs. The molecular interactions between ILs and butanol isomers are essential for understanding the function of ILs in related measures and excess functions are sensitive probe for the molecular interactions. Therefore, we calculated the excess molar volume (VE) and the deviation in isentropic compressibility (Δκs) using the experimental values such as densities (ρ) and ultrasonic sound velocities (u) that are measured over the whole compositions range at five different temperatures (293.15, 298.15, 303.15, 308.15 and 313.15 K) and atmospheric pressure. These excess functions were adequately correlated by using the Redlich–Kister polynomial equation. It was observed that for all studied systems, the VE and Δκs values are negative for the whole composition range at 293.15 K. And, the excess function follows the sequence: 2-butanol>1-butanol>2-methyl-2-propanol, which reveals that (primary or secondary or tertiary) position of hydroxyl group influence the magnitude of interactions with ILs. The negative values of excess functions are contributions from the ion-dipole interaction, hydrogen bonding and packing efficiency between the ILs and butanol isomers. Hence, the position of hydroxyl group plays an important role in the interactions with ILs. The hydrogen bonding features between ILs and alcohols were analysed using molecular modelling program by using HyperChem 7. PMID:24489741

  15. Testing Room-Temperature Ionic Liquid Solutions for Depot Repair of Aluminum Coatings

    Science.gov (United States)

    2011-05-01

    3AlCl4‾ o 100% plating efficiency at 4 amperes/decimeter2 (A/ dm2 ) has been claimed Overview: 1. Remove soils/corrosion products/plating from surfaces 2...room temperature (~90°C) improves activity • Mechanical agitation • Current density of 4 A/ dm2 (example) 4. Rinse and dry plating; Inspect the

  16. Interactions between water and 1-butyl-1-methylpyrrolidinium ionic liquids.

    Science.gov (United States)

    Fadeeva, Tatiana A; Husson, Pascale; DeVine, Jessalyn A; Costa Gomes, Margarida F; Greenbaum, Steven G; Castner, Edward W

    2015-08-14

    We report experimental results on the diffusivity of water in two ionic liquids obtained using the pulsed-gradient spin-echo NMR method. Both ionic liquids have the same cation, 1-butyl-1-methylpyrrolidinium, but different trifluoromethyl-containing anions. One has a strongly hydrophobic anion, bis(trifluoromethylsulfonyl)amide, while the second has a hydrophilic anion, trifluoromethylsulfonate. Transport of water in these ionic liquids is much faster than would be predicted from hydrodynamic laws, indicating that the neutral water molecules experience a very different friction than the anions and cations at the molecular level. Temperature-dependent viscosities, conductivities, and densities are reported as a function of water concentration to further analyze the properties of the ionic liquid-water mixtures. These results on the properties of water in ionic liquids should be of interest to researchers in diverse areas ranging from separations, solubilizing biomass and energy technologies.

  17. Screen-Printed Graphite Electrodes as Low-Cost Devices for Oxygen Gas Detection in Room-Temperature Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Junqiao Lee

    2017-11-01

    Full Text Available Screen-printed graphite electrodes (SPGEs have been used for the first time as platforms to detect oxygen gas in room-temperature ionic liquids (RTILs. Up until now, carbon-based SPEs have shown inferior behaviour compared to platinum and gold SPEs for gas sensing with RTIL solvents. The electrochemical reduction of oxygen (O2 in a range of RTILs has therefore been explored on home-made SPGEs, and is compared to the behaviour on commercially-available carbon SPEs (C-SPEs. Six common RTILs are initially employed for O2 detection using cyclic voltammetry (CV, and two RTILs ([C2mim][NTf2] and [C4mim][PF6] chosen for further detailed analytical studies. Long-term chronoamperometry (LTCA was also performed to test the ability of the sensor surface for real-time gas monitoring. Both CV and LTCA gave linear calibration graphs—for CV in the 10–100% vol. range, and for LTCA in the 0.1–20% vol. range—on the SPGE. The responses on the SPGE were far superior to the commercial C-SPEs; more instability in the electrochemical responses were observed on the C-SPEs, together with some breaking-up or dissolution of the electrode surface materials. This study highlights that not all screen-printed ink formulations are compatible with RTIL solvents for longer-term electrochemical experiments, and that the choice of RTIL is also important. Overall, the low-cost SPGEs appear to be promising platforms for the detection of O2, particularly in [C4mim][PF6].

  18. Supported Ionic Liquid Phase (SILP) catalysis

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Haumann, Marco

    2006-01-01

    Applications of ionic liquids to replace conventional solvents in homogeneous transition-metal catalysis have increased significantly during the last decade. Biphasic ionic liquid/organic liquid systems offer advantages with regard to product separation, catalyst stability, and recycling but util...

  19. Direct Synthesis of Dimethyl Carbonate from Carbon Dioxide and Methanol at Room Temperature Using Imidazolium Hydrogen Carbonate Ionic Liquid as a Recyclable Catalyst and Dehydrant.

    Science.gov (United States)

    Zhao, Tianxiang; Hu, Xingbang; Wu, Dongsheng; Li, Rui; Yang, Guoqiang; Wu, Youting

    2017-05-09

    The direct synthesis of dimethyl carbonate (DMC) from CO2 and CH3 OH was achieved at room temperature with 74 % CH3 OH conversion in the presence of an imidazolium hydrogen carbonate ionic liquid ([Cn Cm Im][HCO3 ]). Experimental and theoretical results reveal that [Cn Cm Im][HCO3 ] can transform quickly into a CO2 adduct, which serves as an effective catalyst and dehydrant. Its dehydration ability is reversible. The energy barrier of the rate-determining step for the DMC synthesis is only 21.7 kcal mol(-1) . The ionic liquid can be reused easily without a significant loss of its catalytic and dehydrating ability. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. High Power Electric Double-Layer Capacitors based on Room-Temperature Ionic Liquids and Nanostructured Carbons

    Science.gov (United States)

    Perez, Carlos R.

    The efficient storage of electrical energy constitutes both a fundamental challenge for 21st century science and an urgent requirement for the sustainability of our technological civilization. The push for cleaner renewable forms of energy production, such as solar and wind power, strongly depends on a concomitant development of suitable storage methods to pair with these intermittent sources, as well as for mobile applications, such as vehicles and personal electronics. In this regard, Electrochemical Double-Layer Capacitors (supercapacitors) represent a vibrant area of research due to their environmental friendliness, long lifetimes, high power capability, and relative underdevelopment when compared to electrochemical batteries. Currently supercapacitors have gravimetric energies one order of magnitude lower than similarly advanced batteries, while conversly enjoying a similar advantage over them in terms of power. The challenge is to increase the gravimentric energies and conserve the high power. On the material side, research focuses on highly porous supports and electrolytes, the critical components of supercapacitors. Through the use of electrolyte systems with a wider electrochemical stability window, as well as properly tailored carbon nanomaterials as electrodes, significant improvements in performance are possible. Room Temperature Ionic Liquids and Carbide-Derived Carbons are promising electrolytes and electrodes, respectively. RTILs have been shown to be stable at up to twice the voltage of organic solvent-salt systems currently employed in supercapacitors, and CDCs are tunable in pore structure, show good electrical conductivity, and superior demonstrated capability as electrode material. This work aims to better understand the interplay of electrode and electrolyte parameters, such as pore structure and ion size, in the ultimate performance of RTIL-based supercapacitors in terms of power, energy, and temperature of operation. For this purpose, carbon

  1. Predictions of Physicochemical Properties of Ionic Liquids with DFT

    Directory of Open Access Journals (Sweden)

    Karl Karu

    2016-07-01

    Full Text Available Nowadays, density functional theory (DFT-based high-throughput computational approach is becoming more efficient and, thus, attractive for finding advanced materials for electrochemical applications. In this work, we illustrate how theoretical models, computational methods, and informatics techniques can be put together to form a simple DFT-based throughput computational workflow for predicting physicochemical properties of room-temperature ionic liquids. The developed workflow has been used for screening a set of 48 ionic pairs and for analyzing the gathered data. The predicted relative electrochemical stabilities, ionic charges and dynamic properties of the investigated ionic liquids are discussed in the light of their potential practical applications.

  2. Aluminium electrodeposition in chloroaluminate ionic liquid.

    Science.gov (United States)

    Zhang, Lipeng; Wang, Enqi; Mu, Jiechen; Yu, Xianjin; Wang, Qiannan; Yang, Lina; Zhao, Zengdian

    2014-08-01

    An efficient microwave enhanced synthesis of ambient temperature chloroaluminate ionic liquid ([EMIM]Br) that preceeds reaction of 1-methylimidazolium with bromoethane in a closed vessel, was described in our work. The reaction time was drastically reduced as compared to the conventional methods. The electrochemical techniques of impedance spectroscopy, cyclic voltammetry and chronoamperometry were used to investigate the mechanism of Al electrodeposition from 2:1 (molar ratio) AlCl3/[EMIM]Br ionic liquid at room temperature. Results indicated that Al electrode- position from this ionic liqud was a quasi-reversible process, and the kinetic complications during the reaction was probably attributed to the electron transfer or mass transport cooperative controlled processes, instantaneous nucleation with diffusion-controlled growth was also investigated. Electrodepositon experiment was conducted using constant current density of 40 mA·cm(-2) for 20 minutes at room temperature and the qualitative analysis of the deposits were performed using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and energy dispersive spectroscope (EDS). The deposits obtained on copper cathode were dense and compact and most Al crystal shows granular structure spherical with high purity.

  3. Membrane separation of ionic liquid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Daniel; Feiring, Andrew Edward; Majumdar, Sudipto; Nemser, Stuart

    2015-09-01

    A membrane separation process using a highly fluorinated polymer membrane that selectively permeates water of an aqueous ionic liquid solution to provide dry ionic liquid. Preferably the polymer is a polymer that includes polymerized perfluoro-2,2-dimethyl-1,3-dioxole (PDD). The process is also capable of removing small molecular compounds such as organic solvents that can be present in the solution. This membrane separation process is suitable for drying the aqueous ionic liquid byproduct from precipitating solutions of biomass dissolved in ionic liquid, and is thus instrumental to providing usable lignocellulosic products for energy consumption and other industrial uses in an environmentally benign manner.

  4. "Practical" Electrospinning of Biopolymers in Ionic Liquids.

    Science.gov (United States)

    Shamshina, Julia L; Zavgorodnya, Oleksandra; Bonner, Jonathan R; Gurau, Gabriela; Di Nardo, Thomas; Rogers, Robin D

    2017-01-10

    To address the need to scale up technologies for electrospinning of biopolymers from ionic liquids to practical volumes, a setup for the multi-needle electrospinning of chitin using the ionic liquid 1-ethyl-3-methylimidazolium acetate, [C2 mim]-[OAc], was designed, built, and demonstrated. Materials with controllable and high surface area were prepared at the nanoscale using ionic-liquid solutions of high-molecular-weight chitin extracted with the same ionic liquid directly from shrimp shells. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. On the viscosity of two 1-butyl-1-methylpyrrolidinium ionic liquids: effect of the temperature and pressure

    DEFF Research Database (Denmark)

    Gaciño, Félix M.; Comuñas, María J.P.; Regueira Muñiz, Teresa

    2015-01-01

    A new calibration procedure was used and four new temperatureprobes have been placed on afalling-body viscometer to improve its accuracy. The new configuration and calibrationprocedure allow measuring viscosities with an uncertainty of 3.5% at pressures up to 150 MPa.This device was employed to m...... ionic liquids. Furthermore, experimental data were used to check the application of the thermodynamic scaling approach as well as the hard-sphere scheme. Both models represent the viscosity values with average relative deviations lower than 2%....

  6. Adsorption Kinetics at Silica Gel/Ionic Liquid Solution Interface

    Directory of Open Access Journals (Sweden)

    Jolanta Flieger

    2015-12-01

    Full Text Available A series of imidazolium and pyridinium ionic liquids with different anions (Cl−, Br−, BF4−, PF6− has been evaluated for their adsorption activity on silica gel. Quantification of the ionic liquids has been performed by the use of RP-HPLC with organic-aqueous eluents containing an acidic buffer and a chaotropic salt. Pseudo-second order kinetic models were applied to the experimental data in order to investigate the kinetics of the adsorption process. The experimental data showed good fitting with this model, confirmed by considerably high correlation coefficients. The adsorption kinetic parameters were determined and analyzed. The relative error between the calculated and experimental amount of ionic liquid adsorbed at equilibrium was within 7%. The effect of various factors such as initial ionic liquid concentration, temperature, kind of solvent, kind of ionic liquid anion and cation on adsorption efficiency were all examined in a lab-scale study. Consequently, silica gel showed better adsorptive characteristics for imidazolium-based ionic liquids with chaotropic anions from aqueous solutions in comparison to pyridinium ionic liquids. The adsorption was found to decrease with the addition of organic solvents (methanol, acetonitrile but it was not sensitive to the change of temperature in the range of 5–40 °C.

  7. Ionic-Liquid-Tethered Nanoparticles: Hybrid Electrolytes

    KAUST Repository

    Moganty, Surya S.

    2010-10-22

    A new class of solventless electrolytes was created by tethering ionic liquids to hard inorganic ZrO2 nanostructures (see picture; NIM=nanoscale ionic material). These hybrid fluids exhibit exceptional redox stability windows, excellent thermal stability, good lithium transference numbers, long-term interfacial stability in the presence of a lithium anode and, when doped with lithium salt, reasonable ionic conductivities.

  8. Role of Solvent and Effect of Substituent on Azobenzene Isomerization by Using Room-Temperature Ionic Liquids as Reaction Media.

    Science.gov (United States)

    Angelini, Guido; Canilho, Nadia; Emo, Mélanie; Kingsley, Molly; Gasbarri, Carla

    2015-08-07

    The effects of a para substituent, as the electron-donating -OCH3 and -OtBu groups and the electron-withdrawing -Br and -F atoms, on azobenzene isomerization have been investigated in a series of imidazolium ionic liquids (BMIM PF6, BMIM BF4, BMIM Tf2N, EMIM Tf2N, BM2IM Tf2N, and HMIM Tf2N). The thermal cis-trans conversion tends to be improved in the presence of the substituent, as pointed out by the first-order rate constants measured at 25 °C. Both the rotation and the inversion mechanisms occur in BMIM Tf2N, EMIM Tf2N, and HMIM Tf2N, as highlighted by typical V-shape Hammett plots, but only rotation takes place in BMIM PF6, BMIM BF4, and BM2IM Tf2N. The possible interactions between the cation and the anion of the solvent and both the isomers of the azobenzene derivatives have been studied by small-wide-angle X-ray scattering (SWAXS). The calculated cis population in the photostationary state and the hardness parameter η of the trans isomer show that azobenzene and F-azobenzene are the less reactive molecules for the trans-cis conversion in all the investigated ionic liquids.

  9. Smectic phases in ionic liquid crystals.

    Science.gov (United States)

    Bartsch, Hendrik; Bier, Markus; Dietrich, S

    2017-11-22

    Ionic liquid crystals (ILCs) are anisotropic mesogenic molecules which carry charges and therefore combine properties of liquid crystals, e.g. the formation of mesophases, and of ionic liquids, such as low melting temperatures and tiny triple-point pressures. Previous density functional calculations have revealed that the phase behavior of ILCs is strongly affected by their molecular properties, i.e. their aspect ratio, the loci of the charges, and their interaction strengths. Here, we report new findings concerning the phase behavior of ILCs as obtained by density functional theory and Monte Carlo simulations. The most important result is the occurrence of a novel, wide smectic-A phase [Formula: see text], at low temperature, the layer spacing of which is larger than that of the ordinary high-temperature smectic-A phase [Formula: see text]. Unlike the ordinary smectic S A phase, the structure of the [Formula: see text] phase consists of alternating layers of particles oriented parallel to the layer normal and oriented perpendicular to it.

  10. Ultrasound-assisted temperature-controlled ionic liquid emulsification microextraction coupled with capillary electrophoresis for the determination of parabens in personal care products.

    Science.gov (United States)

    Ma, Teng; Li, Zheng; Jia, Qiong; Zhou, Weihong

    2016-07-01

    We developed a CE and ultrasound-assisted temperature-controlled ionic liquid emulsification microextraction method for the determination of four parabens (methyl paraben, ethyl paraben, propyl paraben, and butyl paraben) in personal care products including mouthwash and toning lotion. In the proposed extraction procedure, ionic liquid (IL, 1-octyl-3-methylimidazolium hexafluorophosphate) was used as extraction solvent, moreover, no disperser solvent was needed. Parameters affecting the extraction efficiency including volume of IL, heating temperature, ultrasonic time, extraction time, sample pH, ionic strength, and centrifugation time were optimized. Under the optimized conditions, the method was found to be linear over the range of 3-500 ng/mL with coefficient of determination (R(2) ) in the range of 0.9990-0.9998. The LODs and LOQs for the four parabens were 0.45-0.72 ng/mL and 1.50-2.40 ng/mL, respectively. Intraday and interday precisions (RSDs, n = 5) were in the range of 5.4-6.8% and 7.0-8.7%, respectively. The recoveries of parabens at different spiked levels ranged from 71.9 to 119.2% with RSDs less than 9.5%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Long-range electrostatic screening in ionic liquids.

    Science.gov (United States)

    Gebbie, Matthew A; Dobbs, Howard A; Valtiner, Markus; Israelachvili, Jacob N

    2015-06-16

    Electrolyte solutions with high concentrations of ions are prevalent in biological systems and energy storage technologies. Nevertheless, the high interaction free energy and long-range nature of electrostatic interactions makes the development of a general conceptual picture of concentrated electrolytes a significant challenge. In this work, we study ionic liquids, single-component liquids composed solely of ions, in an attempt to provide a novel perspective on electrostatic screening in very high concentration (nonideal) electrolytes. We use temperature-dependent surface force measurements to demonstrate that the long-range, exponentially decaying diffuse double-layer forces observed across ionic liquids exhibit a pronounced temperature dependence: Increasing the temperature decreases the measured exponential (Debye) decay length, implying an increase in the thermally driven effective free-ion concentration in the bulk ionic liquids. We use our quantitative results to propose a general model of long-range electrostatic screening in ionic liquids, where thermally activated charge fluctuations, either free ions or correlated domains (quasiparticles), take on the role of ions in traditional dilute electrolyte solutions. This picture represents a crucial step toward resolving several inconsistencies surrounding electrostatic screening and charge transport in ionic liquids that have impeded progress within the interdisciplinary ionic liquids community. More broadly, our work provides a previously unidentified way of envisioning highly concentrated electrolytes, with implications for diverse areas of inquiry, ranging from designing electrochemical devices to rationalizing electrostatic interactions in biological systems.

  12. Temperature and chain length dependence of ultrafast vibrational dynamics of thiocyanate in alkylimidazolium ionic liquids: A random walk on a rugged energy landscape

    Science.gov (United States)

    Brinzer, Thomas; Garrett-Roe, Sean

    2017-11-01

    Ultrafast two-dimensional infrared spectroscopy of a thiocyanate vibrational probe (SCN-) was used to investigate local dynamics in alkylimidazolium bis-[trifluoromethylsulfonyl]imide ionic liquids ([Imn,1][Tf2N], n = 2, 4, 6) at temperatures from 5 to 80 °C. The rate of frequency fluctuations reported by SCN- increases with increasing temperature and decreasing alkyl chain length. Temperature-dependent correlation times scale proportionally to temperature-dependent bulk viscosities of each ionic liquid studied. A multimode Brownian oscillator model demonstrates that very low frequency (modes primarily drive the observed spectral diffusion and that these modes broaden and blue shift on average with increasing temperature. An Arrhenius analysis shows activation barriers for local motions around the probe between 5.5 and 6.5 kcal/mol that are very similar to those for translational diffusion of ions. [Im6,1][Tf2N] shows an unexpected decrease in activation energy compared to [Im4,1][Tf2N] that may be related to mesoscopically ordered polar and nonpolar domains. A model of dynamics on a rugged potential energy landscape provides a unifying description of the observed Arrhenius behavior and the Brownian oscillator model of the low frequency modes.

  13. Improved ionic model of liquid uranium dioxide

    NARCIS (Netherlands)

    Gryaznov, [No Value; Iosilevski, [No Value; Yakub, E; Fortov, [No Value; Hyland, GJ; Ronchi, C

    The paper presents a model for liquid uranium dioxide, obtained by improving a simplified ionic model, previously adopted to describe the equation of state of this substance [1]. A "chemical picture" is used for liquid UO2 of stoichiometric and non-stoichiometric composition. Several ionic species

  14. Aqueous solutions of ionic liquids: microscopic assembly

    NARCIS (Netherlands)

    Vicent-Luna, J.M.; Dubbeldam, D.; Gómez-Álvarez, P.; Calero, S.

    2016-01-01

    Aqueous solutions of ionic liquids are of special interest, due to the distinctive properties of ionic liquids, in particular, their amphiphilic character. A better understanding of the structure-property relationships of such systems is hence desirable. One of the crucial molecular-level

  15. Engineered microorganisms having resistance to ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Ruegg, Thomas Lawrence; Thelen, Michael P.

    2016-03-22

    The present invention provides for a method of genetically modifying microorganisms to enhance resistance to ionic liquids, host cells genetically modified in accordance with the methods, and methods of using the host cells in a reaction comprising biomass that has been pretreated with ionic liquids.

  16. Notre Dame Geothermal Ionic Liquids Research: Ionic Liquids for Utilization of Geothermal Energy

    Energy Technology Data Exchange (ETDEWEB)

    Brennecke, Joan F. [Univ. of Notre Dame, IN (United States)

    2017-03-07

    The goal of this project was to develop ionic liquids for two geothermal energy related applications. The first goal was to design ionic liquids as high temperature heat transfer fluids. We identified appropriate compounds based on both experiments and molecular simulations. We synthesized the new ILs, and measured their thermal stability, measured storage density, viscosity, and thermal conductivity. We found that the most promising compounds for this application are aminopyridinium bis(trifluoromethylsulfonyl)imide based ILs. We also performed some measurements of thermal stability of IL mixtures and used molecular simulations to better understand the thermal conductivity of nanofluids (i.e., mixtures of ILs and nanoparticles). We found that the mixtures do not follow ideal mixture theories and that the addition of nanoparticles to ILs may well have a beneficial influence on the thermal and transport properties of IL-based heat transfer fluids. The second goal was to use ionic liquids in geothermally driven absorption refrigeration systems. We performed copious thermodynamic measurements and modeling of ionic liquid/water systems, including modeling of the absorption refrigeration systems and the resulting coefficients of performance. We explored some IL/organic solvent mixtures as candidates for this application, both with experimentation and molecular simulations. We found that the COPs of all of the IL/water systems were higher than the conventional system – LiBr/H2O. Thus, IL/water systems appear very attractive for absorption refrigeration applications.

  17. Lead-Salt Quantum-Dot Ionic Liquids

    KAUST Repository

    Sun, Liangfeng

    2010-03-08

    PbS quantum dots (QDs) are functionalized using ionic liquids with thiol moieties as capping ligands. The resulting amphiphilic QD ionic liquids exhibit fluidlike behavior at room temperature, even in the absence of solvents. The photostability of the QDs is dramatically improved compared to the as-synthesized oleic acid-capped QDs dispersed in toluene. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. ZnO-ionic liquid nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Sanes, Jose; Carrion, Francisco-Jose [Grupo de Ciencia de Materiales e Ingenieria Metalurgica, Departamento de Ingenieria de Materiales y Fabricacion, Universidad Politecnica de Cartagena, Campus de la Muralla del Mar, C/ Doctor Fleming s/n, 30202 Cartagena (Spain); Bermudez, Maria-Dolores, E-mail: mdolores.bermudez@upct.es [Grupo de Ciencia de Materiales e Ingenieria Metalurgica, Departamento de Ingenieria de Materiales y Fabricacion, Universidad Politecnica de Cartagena, Campus de la Muralla del Mar, C/ Doctor Fleming s/n, 30202 Cartagena (Spain)

    2009-02-15

    The mixture of nanostructures derived from the surface interactions and reactivity of ZnO nanoparticles with the room-temperature ionic liquid (IL1) 1-hexyl, 3-methylimidazolium hexafluorophosphate has been studied. Results are discussed on the basis of transmission electron microscopy (TEM) observations, energy dispersive spectroscopy (EDS) analysis, X-ray diffraction (XRD) patterns and X-ray photoelectron spectroscopy (XPS) determinations. Size and morphology changes in ZnO nanoparticles by surface modification with IL1 are observed. ZnF{sub 2} crystalline needles due to reaction with the hexafluorophosphate anion are also formed.

  19. Comparing two tetraalkylammonium ionic liquids. I. Liquid phase structure

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Thamires A.; Paschoal, Vitor H.; Faria, Luiz F. O.; Ribeiro, Mauro C. C., E-mail: mccribei@iq.usp.br [Laboratório de Espectroscopia Molecular, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, CP 26077, CEP 05513-970 São Paulo, SP (Brazil); Giles, Carlos [Departamento de Física da Matéria Condensada, Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, 13083-859 Campinas, SP (Brazil)

    2016-06-14

    X-ray scattering experiments at room temperature were performed for the ionic liquids n-butyl-trimethylammonium bis(trifluoromethanesulfonyl)imide, [N{sub 1114}][NTf{sub 2}], and methyl-tributylammonium bis(trifluoromethanesulfonyl)imide, [N{sub 1444}][NTf{sub 2}]. The peak in the diffraction data characteristic of charge ordering in [N{sub 1444}][NTf{sub 2}] is shifted to longer distances in comparison to [N{sub 1114}][NTf{sub 2}], but the peak characteristic of short-range correlations is shifted in [N{sub 1444}][NTf{sub 2}] to shorter distances. Molecular dynamics (MD) simulations were performed for these ionic liquids using force fields available from the literature, although with new sets of partial charges for [N{sub 1114}]{sup +} and [N{sub 1444}]{sup +} proposed in this work. The shifting of charge and adjacency peaks to opposite directions in these ionic liquids was found in the static structure factor, S(k), calculated by MD simulations. Despite differences in cation sizes, the MD simulations unravel that anions are allowed as close to [N{sub 1444}]{sup +} as to [N{sub 1114}]{sup +} because anions are located in between the angle formed by the butyl chains. The more asymmetric molecular structure of the [N{sub 1114}]{sup +} cation implies differences in partial structure factors calculated for atoms belonging to polar or non-polar parts of [N{sub 1114}][NTf{sub 2}], whereas polar and non-polar structure factors are essentially the same in [N{sub 1444}][NTf{sub 2}]. Results of this work shed light on controversies in the literature on the liquid structure of tetraalkylammonium based ionic liquids.

  20. Harnessing Poly(ionic liquid)s for Sensing Applications

    OpenAIRE

    Guterman, Ryan; Ambrogi, Martina; Yuan, Jiayin

    2016-01-01

    The interest in poly(ionic liquids) for sensing applications are derived from their strong interactions to a variety of analytes. By combining the desirable mechanical properties of polymers with the physical and chemical properties of ILs, new materials can be created. The tunable nature of both ionic liquids and polymers allows for incredible diversity, which is exemplified in their broad applicability. In this article we examine the new field of poly(ionic liquid) sensors by providing a de...

  1. A new room temperature ionic liquid 1-butyl-3-trimethylsilylimidazolium hexafluorophosphate as a solvent for extraction and preconcentration of mercury with determination by cold vapor atomic absorption spectrometry.

    Science.gov (United States)

    Li, Zaijun; Wei, Qin; Yuan, Rui; Zhou, Xia; Liu, Huizhen; Shan, Haixia; Song, Qijun

    2007-01-15

    A new room temperature ionic liquid 1-butyl-3-trimethylsilylimidazolium hexafluorophosphate abbreviated as [C(4)tmsim][PF(6)] was synthesized and developed as a novel medium for liquid/liquid extraction of inorganic mercury in this work. Under optimal condition, o-carboxyphenyldiazoamino-p-azobenzene abbreviated as CDAA reacted with inorganic mercury to form a neutral Hg-CDAA complex, the complex was rapidly extracted into ionic liquid phase. After back-extracting into aqueous phase with sulfide sodium solution, the mercury concentration was detected by cold vapor atomic absorption spectrometry. The extraction and back-extraction efficiencies were 99.9 and 100.1% for 5.0microg L(-1) standard mercury in 1000mL of water solution, respectively. The detection limit, calculated using three times the standard error of estimate of the calibration graph, is 0.01ng of mercury per milliliter water sample. The proposed method has been used to the determination of trace inorganic mercury in natural water with satisfactory results. Moreover, Zeta potential and surface tension of [C(4)tmsim][PF(6)] solution were measured and applied to explain the extraction mechanism of [C(4)tmsim][PF(6)] system.

  2. Fast Conversion of Ionic Liquids and Poly(Ionic Liquids into Porous Nitrogen-Doped Carbons in Air

    Directory of Open Access Journals (Sweden)

    Yongjun Men

    2016-04-01

    Full Text Available Ionic liquids and poly(ionic liquids have been successfully converted into nitrogen-doped porous carbons with tunable surface area up to 1200 m2/g at high temperatures in air. Compared to conventional carbonization process conducted under inert gas to produce nitrogen-doped carbons, the new production method was completed in a rather shorter time without noble gas protection.

  3. Carprofen-imprinted monolith prepared by reversible addition-fragmentation chain transfer polymerization in room temperature ionic liquids.

    Science.gov (United States)

    Ban, Lu; Han, Xu; Wang, Xian-Hua; Huang, Yan-Ping; Liu, Zhao-Sheng

    2013-10-01

    To obtain fast separation, ionic liquids were used as porogens first in combination with reversible addition-fragmentation chain transfer (RAFT) polymerization to prepare a new type of molecularly imprinted polymer (MIP) monolith. The imprinted monolithic column was synthesized using a mixture of carprofen (template), 4-vinylpyridine, ethylene glycol dimethacrylate, [BMIM]BF4, and chain transfer agent (CTA). Some polymerization factors, such as template-monomer molar ratio, the degree of crosslinking, the composition of the porogen, and the content of CTA, on the column efficiency and imprinting effect of the resulting MIP monolith were systematically investigated. Affinity screening of structurally similar compounds with the template can be achieved in 200 s on the MIP monolith due to high column efficiency (up to 12,070 plates/m) and good column permeability. Recognition mechanism of the imprinted monolith was also investigated.

  4. Extraction of proteins with ionic liquid aqueous two-phase system based on guanidine ionic liquid.

    Science.gov (United States)

    Zeng, Qun; Wang, Yuzhi; Li, Na; Huang, Xiu; Ding, Xueqin; Lin, Xiao; Huang, Songyun; Liu, Xiaojie

    2013-11-15

    Eight kinds of green ionic liquids were synthesized, and an ionic liquid aqueous two-phase system (ILATPS) based on 1,1,3,3-tetramethylguandine acrylate (TMGA) guanidine ionic liquid was first time studied for the extraction of proteins. Single factor experiments proved that the extraction efficiency of bovine serum albumin (BSA) was influenced by the mass of IL, K2HPO4 and BSA, also related to the separation time and temperature. The optimum conditions were determined through orthogonal experiment by the five factors described above. The results showed that under the optimum conditions, the extraction efficiency could reach up to 99.6243%. The relative standard deviations (RSD) of extraction efficiencies in precision experiment, repeatability experiment and stability experiment were 0.8156% (n=5), 1.6173% (n=5) and 1.6292% (n=5), respectively. UV-vis and FT-IR spectra confirmed that there were no chemical interactions between BSA and ionic liquid in the extraction process, and the conformation of the protein was not changed after extraction. The conductivity, DLS and TEM were combined to investigate the microstructure of the top phase and the possible mechanism for the extraction. The results showed that hydrophobic interaction, hydrogen bonding interaction and the salt out effect played important roles in the transferring process, and the aggregation and embrace phenomenon was the main driving force for the separation. All these results proved that guanidine ionic liquid-based ATPSs have the potential to offer new possibility in the extraction of proteins. © 2013 Elsevier B.V. All rights reserved.

  5. Novel method of room temperature ionic liquid assisted Fe{sub 3}O{sub 4} nanocubes and nanoflakes synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Ramalakshmi, M. [Sustainable Energy and Smart Materials Lab., Department of Nanoscience and Technology, Alagappa University, Karaikudi 630 002, Tamilnadu (India); Department of Industrial Chemistry, Alagappa University, Karaikudi India (India); Shakkthivel, P., E-mail: apsakthivel@yahoo.com [Sustainable Energy and Smart Materials Lab., Department of Nanoscience and Technology, Alagappa University, Karaikudi 630 002, Tamilnadu (India); Sundrarajan, M. [Department of Industrial Chemistry, Alagappa University, Karaikudi India (India); Chen, S.M. [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, Taiwan (China)

    2013-08-01

    Graphical abstract: - Highlights: • First time [Bmim][TfO] IL is used for the Fe{sub 3}O{sub 4} nanoparticle synthesis. • Novel method tunes Fe{sub 3}O{sub 4} nanocubes and nanoflakes forms influenced by the base and IL. • Fe{sub 3}O{sub 4} oxidized topotactically into γ-Fe{sub 2}O{sub 3} nanoparticles by annealing and base. • Uniform morphology with average size of 33 nm negligible superstructure are formed. • Ms values are characterized by thin layer of γ-Fe{sub 2}O{sub 3} on the nanoparticle surface. - Abstract: For the first time, the nanomagnetite superparamagnetic particles are successfully synthesized by precipitation method using 1-n-butyl-3-methylimidazolium trifluoromethane sulfonate [Bmim][TfO] ionic liquid medium/surfactant. The obtained Fe{sub 3}O{sub 4} particles are nanocubes and nanoflakes and this formation is influenced by the base concentration and anisotropic circumstances produced by the ionic liquid and their size varies from 20 nm to 150 × 300 nm (width × length). The synthesized magnetite nanoparticles are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, Field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM) and Vibrating sample magnetometer (VSM) studies. The results show that the core of the Fe{sub 3}O{sub 4} nanoparticles is surrounded by a thin layer of γ-Fe{sub 2}O{sub 3} by topotactical partial oxidation, which is remarkably proceed with the subsequent calcination. The magnetite nanocubes have high saturation magnetization value and exhibit superparamagnetic hysteresis loop.

  6. The structure of ionic liquids

    CERN Document Server

    Gontrani, Lorenzo

    2014-01-01

    This volume describes the most recent findings on the structure of ILs interpreted through cutting-edge experimental and theoretical methods. Research in the field of ionic liquids (ILs) keeps a fast and steady pace. Since these new-generation molten salts first appeared in the chemistry and physics landscape, a large number of new compounds has been synthesized. Most of them display unexpected behaviour and possess stunning properties. The coverage in this book ranges from the mesoscopic structure of ILs to their interaction with proteins. The reader will learn how diffraction techniques (small and large angle X-Ray and neutron scattering, powder methods), X-Ray absorption spectroscopies (EXAFS/XANES), optical methods (IR, RAMAN), NMR and calorimetric methods can help the study of ILs, both as neat liquids and in mixtures with other compounds. It will enable the reader to choose the best method to suit their experimental needs. A detailed survey of theoretical methods, both quantum-chemical and classical, ...

  7. Aerogels from Chitosan Solutions in Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Gonzalo Santos-López

    2017-12-01

    Full Text Available Chitosan aerogels conjugates the characteristics of nanostructured porous materials, i.e., extended specific surface area and nano scale porosity, with the remarkable functional properties of chitosan. Aerogels were obtained from solutions of chitosan in ionic liquids (ILs, 1-butyl-3-methylimidazolium acetate (BMIMAc, and 1-ethyl-3-methyl-imidazolium acetate (EMIMAc, in order to observe the effect of the solvent in the structural characteristics of this type of materials. The process of elaboration of aerogels comprised the formation of physical gels through anti-solvent vapor diffusion, liquid phase exchange, and supercritical CO2 drying. The aerogels maintained the chemical identity of chitosan according to Fourier transform infrared spectrophotometer (FT-IR spectroscopy, indicating the presence of their characteristic functional groups. The internal structure of the obtained aerogels appears as porous aggregated networks in microscopy images. The obtained materials have specific surface areas over 350 m2/g and can be considered mesoporous. According to swelling experiments, the chitosan aerogels could absorb between three and six times their weight of water. However, the swelling and diffusion coefficient decreased at higher temperatures. The structural characteristics of chitosan aerogels that are obtained from ionic liquids are distinctive and could be related to solvation dynamic at the initial state.

  8. Densities and isothermal compressibilities of ionic liquids - Modelling and application

    DEFF Research Database (Denmark)

    Abildskov, Jens; Ellegaard, Martin Dela; O’Connell, J.P.

    2010-01-01

    Two corresponding-states forms have been developed for direct correlation function integrals in liquids to represent pressure effects on the volume of ionic liquids over wide ranges of temperature and pressure. The correlations can be analytically integrated from a chosen reference density to pro...

  9. Recent development of ionic liquid stationary phases for liquid chromatography.

    Science.gov (United States)

    Shi, Xianzhe; Qiao, Lizhen; Xu, Guowang

    2015-11-13

    Based on their particular physicochemical characteristics, ionic liquids have been widely applied in many fields of analytical chemistry. Many types of ionic liquids were immobilized on a support like silica or monolith as stationary phases for liquid chromatography. Moreover, different approaches were developed to bond covalently ionic liquids onto the supporting materials. The obtained ionic liquid stationary phases show multi-mode mechanism including hydrophobic, hydrophilic, hydrogen bond, anion exchange, π-π, and dipole-dipole interactions. Therefore, they could be used in different chromatographic modes including ion-exchange, RPLC, NPLC and HILIC to separate various classes of compounds. This review mainly summarizes the immobilized patterns and types of ionic liquid stationary phases, their retention mechanisms and applications in the recent five years. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Ionic Liquids: Synthesis and Applications in Catalysis

    Directory of Open Access Journals (Sweden)

    Rajni Ratti

    2014-01-01

    Full Text Available Ionic liquids have emerged as an environmentally friendly alternative to the volatile organic solvents. Being designer solvents, they can be modulated to suit the reaction conditions, therefore earning the name “task specific ionic liquids.” Though primarily used as solvents, they are now finding applications in various fields like catalysis, electrochemistry, spectroscopy, and material science to mention a few. The present review is aimed at exploring the applications of ionic liquids in catalysis as acid, base, and organocatalysts and as soluble supports for catalysts.

  11. Density, viscosity and phase equilibria study of {ethylsulfate-based ionic liquid + water} binary systems as a function of temperature and composition

    Energy Technology Data Exchange (ETDEWEB)

    Królikowska, Marta, E-mail: mlaskowska@ch.pw.edu.pl; Lipiński, Paweł; Maik, Daria

    2014-04-01

    Highlights: • The [EMPIP][EtSO{sub 4}], [EMMOR][EtSO{sub 4}], [EMPYR][EtSO{sub 4}] and its aqueous mixtures have been studied. • The density, dynamic viscosity and SLE have been determined. • The excess molar volumes and viscosity deviations have been calculated. • The NRTL, Wilson, UNIQUAC, Redlich–Kister and VFT equations have been used to correlate the experimental data. - Abstract: This paper is a continuation of our investigation on physicochemical and thermodynamic properties of ionic liquids and its aqueous solutions. In this work the density, ρ and dynamic viscosity, η have been determined for binary mixtures of the ionic liquids: 1-ethyl-1-methyl-piperidinium ethylsulfate, [EMPIP][EtSO{sub 4}], 1-ethyl-1-methylmorpholinium ethylsulfate, [EMMOR][EtSO{sub 4}] and 1-ethyl-1-methylpyrrolidinium ethylsulfate, [EMPYR][EtSO{sub 4}] with water at wide temperature and composition range at atmospheric pressure. From experimental values of the density, ρ and dynamic viscosity, η the excess molar volumes, V{sup E} and viscosity deviations, Δη were calculated and correlated using Redlich–Kister polynomial equation. The (solid + liquid) phase equilibria, SLE for the tested binary mixtures have been determined by well-known dynamic method at a wide range of composition and temperature at atmospheric pressure. For comparison, the SLE data for {[EMPYR][EtSO_4] + water} binary mixtures have been determined using DSC technique. The experimental SLE data have been correlated by means of NRTL, UNIQUAC and Wilson equations. Additionally, the basic thermal properties of the pure ILs, that is, the glass-transition temperature, T{sub g,1} as well as the heat capacity at the glass-transition temperature, ΔC{sub p(g),1}, melting temperature, T{sub m} and enthalpy of melting, Δ{sub m}H have been measured using a differential scanning microcalorimetry technique (DSC). Decomposition of the ILs was detected by the simultaneous TG/DTA experiments. The choice of the

  12. Tuning the stimuli-responsive properties of poly(ionic liquid)s

    OpenAIRE

    Tudor, Alexandru; Florea, Larisa; Diamond, Dermot

    2015-01-01

    Poly(Ionic Liquid)s (PILs) are a class of ionic liquids that feature polymerizable groups in either the cation, the anion or both. PILs can be used in various applications, including solid ion conductors or for CO2 absorption. Several PILs show the presence of a lower critical solution temperature (LCST), making them suitable precursors for the synthesis of stimuli-responsive materials that have the ability to change their conformation in response to variations in their external environment. ...

  13. Excess enthalpies of mixing, effect of temperature and composition on the density, and viscosity and thermodynamic properties of binary systems of {ammonium-based ionic liquid + alkanediol}.

    Science.gov (United States)

    Domańska, Urszula; Papis, Paulina; Szydłowski, Jerzy; Królikowska, Marta; Królikowski, Marek

    2014-11-06

    In the present work the excess enthalpies of butyltrimethylammonium bis(trifluoromethyl-sulfonyl)imide, [N1114][NTf2], with 1,2-propanediol, or 1,2-butanediol, or 2,3-butanediol have been measured at T = 298.15 K. Additionally, the density, ρ, and dynamic viscosity, η, for binary solutions containing ionic liquids (ILs) and alkanedioles, {butyltrimethylammonium bis(trifluoromethyl-sulfonyl)imide, [N1114][NTf2], + 1,2-propanediol, 1,2-butanediol, 2,3-butanediol} and {(2-hydroxyethyl)trimethylammonium bis(trifluoro-methylsulfonyl)imide, [N1112OH][NTf2], + 1,2-propanediol, 1,3-propanediol, 1,5-pentanediol}, at wide temperature and composition ranges at ambient pressure have been investigated. From experimental values of the density, ρ, and dynamic viscosity, η, the excess molar volumes, V(E), and dynamic viscosity deviations, Δη, were calculated and correlated using the Redlich-Kister polynomial equation. The temperature dependence of density and viscosity for the tested binary systems was described by an empirical second-order polynomial and by the Vogel-Fucher-Tammann equation, respectively. The variation of density and viscosity as a function of composition has been described by the polynomial correlations. Comparison of the experimental results for the binary mixtures tested in this work allows us to determine the influence of alkanediol carbon chain length, the position of the hydroxyl group in the alcohol, and the influence of the structure of the cation of the ionic liquid on the presented properties.

  14. Alkaline ionic liquids applied in supported ionic liquid catalyst for selective hydrogenation of citral to citronellal

    Directory of Open Access Journals (Sweden)

    Eero eSalminen

    2014-02-01

    Full Text Available The challenge in preparation of ionic liquids containing a strong alkaline anion is to identify a suitable cation which can tolerate the harsh conditions induced by the anion. In this study, a commercial quaternary ammonium compound (quat benzalkonium [ADBA] (alkyldimethylbenzylammonium was used as a cation in the synthesis of different alkaline ionic liquids. In fact, the precursor, benzalkonium chloride, is a mixture of alkyldimethylbenzylammonium chlorides of various alkyl chain lengths and is commonly used in the formulation of various antiseptic products. The prepared ionic liquids were utilized as Supported Ionic Liquid Catalysts (SILCAs. Typically, a SILCA contains metal nanoparticles, enzymes or metal complexes in an ionic liquid layer which is immobilized on a solid carrier material such as an active carbon cloth (ACC. The catalysts were applied in the selective hydrogenation of citral to citronellal which is an important perfumery chemical. Interestingly, 70 % molar yield towards citronellal was achieved over a catalyst containing the alkaline ionic liquid benzalkonium methoxide.

  15. Alkaline ionic liquids applied in supported ionic liquid catalyst for selective hydrogenation of citral to citronellal

    Science.gov (United States)

    Salminen, Eero; Virtanen, Pasi; Mikkola, Jyri-Pekka

    2014-02-01

    The challenge in preparation of ionic liquids containing a strong alkaline anion is to identify a suitable cation which can tolerate the harsh conditions induced by the anion. In this study, a commercial quaternary ammonium compound (quat) benzalkonium [ADBA] (alkyldimethylbenzylammonium) was used as a cation in the synthesis of different alkaline ionic liquids. In fact, the precursor, benzalkonium chloride, is a mixture of alkyldimethylbenzylammonium chlorides of various alkyl chain lengths and is commonly used in the formulation of various antiseptic products. The prepared ionic liquids were utilized as Supported Ionic Liquid Catalysts (SILCAs). Typically, a SILCA contains metal nanoparticles, enzymes or metal complexes in an ionic liquid layer which is immobilized on a solid carrier material such as an active carbon cloth (ACC). The catalysts were applied in the selective hydrogenation of citral to citronellal which is an important perfumery chemical. Interestingly, 70 % molar yield towards citronellal was achieved over a catalyst containing the alkaline ionic liquid benzalkonium methoxide.

  16. Determination of sulfonamides in butter samples by ionic liquid magnetic bar liquid-phase microextraction high-performance liquid chromatography.

    Science.gov (United States)

    Wu, Lijie; Song, Ying; Hu, Mingzhu; Xu, Xu; Zhang, Hanqi; Yu, Aimin; Ma, Qiang; Wang, Ziming

    2015-01-01

    A novel, simple, and environmentally friendly pretreatment method, ionic liquid magnetic bar liquid-phase microextraction, was developed for the determination of sulfonamides in butter samples by high-performance liquid chromatography. The ionic liquid magnetic bar was prepared by inserting a stainless steel wire into the hollow of a hollow fiber and immobilizing ionic liquid in the micropores of the hollow fiber. In the extraction process, the ionic liquid magnetic bars were used to stir the mixture of sample and extraction solvent and enrich the sulfonamides in the mixture. After extraction, the analyte-adsorbed ionic liquid magnetic bars were readily isolated with a magnet from the extraction system. It is notable that the present method was environmentally friendly since water and only several microliters of ionic liquid were used in the whole extraction process. Several parameters affecting the extraction efficiency were investigated and optimized, including the type of ionic liquid, sample-to-extraction solvent ratio, the number of ionic liquid magnetic bars, extraction temperature, extraction time, salt concentration, stirring speed, pH of the extraction solvent, and desorption conditions. The recoveries were in the range of 73.25-103.85 % and the relative standard deviations were lower than 6.84 %. The experiment results indicated that the present method was effective for the extraction of sulfonamides in high-fat content samples.

  17. Ionic Liquids with Ammonium Cations as Lubricants or Additives

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jun [ORNL; Blau, Peter Julian [ORNL; Dai, Sheng [ORNL; Luo, Huimin [ORNL; Truhan, Jr., John J [ORNL

    2006-01-01

    Friction and wear are estimated to cost 6% of the US gross national product, or around $700 billion annually. A new class of more effective lubricants could lead to huge energy savings. Limited recent literature has suggested potential for using room-temperature ionic liquids as lubricants, however only a few out of millions (or more) of species have been evaluated. Recent ORNL work discovered a new category of ionic liquids with ammonium cations that have demonstrated promising lubricating properties as net lubricants or lubricant additives, particularly in lubricating difficult-to-lubricate metals like aluminum. More than 30% friction reduction has been observed on ammonium-based ionic liquids compared to conventional hydrocarbon oils. The inherent polarity of ionic liquids is believed to provide strong adhesion to contact surfaces and form a boundary lubricating film leading to friction and wear reductions. Other advantages of ionic liquids include (1) negligible volatility, (2) high thermal stability, (3) non-flammability, and (4) better intrinsic properties that eliminate the necessity of many expensive lubricant additives. With very flexible molecular structures, this new class of lubricants, particularly ammonium-based ionic liquids, can be tailored to fit a big variety of applications including but not limited to bearings, combustion engines, MEMS, and metal forming.

  18. Ionic Liquid Immobilized Organocatalysts for Asymmetric Reactions in Aqueous Media

    Directory of Open Access Journals (Sweden)

    Allan D. Headley

    2013-09-01

    Full Text Available Ionic liquids are organic salts with melting points typically below ambient or reaction temperature. The unique combination of physical properties of ionic liquids, such as lack of measurable vapor pressure, high thermal and chemical stability, make them ideal to be used as reusable homogenous support for catalysts. In addition, the solubility of ionic liquids in various reaction media can be controlled and easily fine-tuned by modification of the structures of their cations and anions. As a result, ionic liquid immobilized organocatalysts are very effective in aqueous media and can be separated easily from organic solvents, as well as aqueous phases by simply adjusting the polarity of the media. Ionic liquid immobilized organocatalysts are not only very versatile compounds that are effective catalysts for a wide spectrum of reactions, but are also environmentally friendly and recyclable organocatalysts. Herein, we provide a summary of the past decade in the area of asymmetric catalysis in aqueous media for a wide variety of reactions in which ionic liquid and related ammonium salt immobilized organocatalysts are used.

  19. Modeling electrokinetics in ionic liquids: General

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chao [Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland WA USA; Bao, Jie [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA USA; Pan, Wenxiao [Department of Mechanical Engineering, University of Wisconsin-Madison, Madison WI USA; Sun, Xin [Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland WA USA

    2017-04-07

    Using direct numerical simulations we provide a thorough study on the electrokinetics of ionic liquids. In particular, the modfied Poisson-Nernst-Planck (MPNP) equations are solved to capture the crowding and overscreening effects that are the characteristics of an ionic liquid. For modeling electrokinetic flows in an ionic liquid, the MPNP equations are coupled with the Navier-Stokes equations to study the coupling of ion transport, hydrodynamics, and electrostatic forces. Specifically, we consider the ion transport between two parallel plates, charging dynamics in a 2D straight-walled pore, electro-osmotic ow in a nano-channel, electroconvective instability on a plane ion-selective surface, and electroconvective ow on a curved ion-selective surface. We discuss how the crowding and overscreening effects and their interplay affect the electrokinetic behaviors of ionic liquids in these application problems.

  20. Ionic Liquid Epoxy Composite Cryotanks Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this work is to determine the optimal process for manufacturing lightweight linerless cryogenic storage tanks using ionic liquid epoxy composite...

  1. Ionic liquid polyoxometalates as light emitting materials

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz-acosta, Denisse [Los Alamos National Laboratory; Del Sesto, Rico E [Los Alamos National Laboratory; Scott, Brian [Los Alamos National Laboratory; Bennett, Bryan L [Los Alamos National Laboratory; Purdy, Geraldine M [Los Alamos National Laboratory; Muenchausen, Ross E [Los Alamos National Laboratory; Mc Kigney, Edward [Los Alamos National Laboratory; Gilbertson, Robert [Los Alamos National Laboratory

    2008-01-01

    The low melting point, negligible vapor pressure, good solubility, and thermal and chemical stability make ionic liquids useful materials for a wide variety of applications. Polyoxometalates are early transition metal oxygen clusters that can be synthesized in many different sizes and with a variety of heterometals. The most attractive feature of POMs is that their physical properties, in particular electrical, magnetic, and optical properties, can be easily modified following known procedures. It has been shown that POMs can exhibit cooperative properties, as superconductivity and energy transfer. POM ionic liquids can be obtained by selecting the appropliate cation. Different alkyl ammonium and alkyl phosphonium salts are being used to produce new POM ionic liquids together with organic or inorganic luminescent centers to design light emitting materials. Ammonium and phosphonium cations with activated, polymerizable groups are being used to further polymerize the ionic liquid into transparent, solid materials with high metal density.

  2. The Solubility Parameters of Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Andrzej Marciniak

    2010-04-01

    Full Text Available The Hildebrand’s solubility parameters have been calculated for 18 ionic liquids from the inverse gas chromatography measurements of the activity coefficients at infinite dilution. Retention data were used for the calculation. The solubility parameters are helpful for the prediction of the solubility in the binary solvent mixtures. From the solubility parameters, the standard enthalpies of vaporization of ionic liquids were estimated.

  3. Study of thioglycosylation in ionic liquids

    Directory of Open Access Journals (Sweden)

    Ragauskas Arthur

    2006-06-01

    Full Text Available Abstract A novel, green chemistry, glycosylation strategy was developed based upon the use of ionic liquids. Research studies demonstrated that thiomethyl glycosides could readily be activated with methyl trifluoromethane sulfonate, using 1-butyl-3-methylimidazolium tetrafluoroborate as a solvent. This green chemistry glycosylation strategy provided disaccharides with typical yields averaging 75%. The ionic liquid solvent could be readily reused for five sequential glycosylation reactions with no impact on product yield.

  4. Superbase-derived protic ionic liquids

    Science.gov (United States)

    Dai, Sheng; Luo, Huimin; Baker, Gary A.

    2013-09-03

    Protic ionic liquids having a composition of formula (A.sup.-)(BH.sup.+) wherein A.sup.- is a conjugate base of an acid HA, and BH.sup.+ is a conjugate acid of a superbase B. In particular embodiments, BH.sup.+ is selected from phosphazenium species and guanidinium species encompassed, respectively, by the general formulas: ##STR00001## The invention is also directed to films and membranes containing these protic ionic liquids, with particular application as proton exchange membranes for fuel cells.

  5. Anodic dissolution of metals in ionic liquids

    Directory of Open Access Journals (Sweden)

    Andrew P. Abbott

    2015-12-01

    Full Text Available The anodic dissolution of metals is an important topic for battery design, material finishing and metal digestion. Ionic liquids are being used in all of these areas but the research on the anodic dissolution is relatively few in these media. This study investigates the behaviour of 9 metals in an ionic liquid [C4mim][Cl] and a deep eutectic solvent, Ethaline, which is a 1:2 mol ratio mixture of choline chloride and ethylene glycol. It is shown that for the majority of metals studied a quasi-passivation of the metal surface occurs, primarily due to the formation of insoluble films on the electrode surface. The behaviour of most metals is different in [C4mim][Cl] to that in Ethaline due in part to the differences in viscosity. The formation of passivating salt films can be decreased with stirring or by increasing the electrolyte temperature, thereby increasing ligand transport to the electrode surface.

  6. The Ho(III) as structural probe for high temperature ionic liquids: RCl 3 (R = rare earth)

    Science.gov (United States)

    Chrissanthopoulos, A.; Papatheodorou, G. N.

    2008-12-01

    The electronic absorption spectra of the f ← f transitions of Ho 3+ as a probe cation doped in solid and liquid YCl 3 and TbCl 3 have been measured from room temperature to above the melting point of both compounds. In the same temperature range Raman spectroscopy has been utilized to characterize all phases present. Emphasis is given on the Ho 3+ ligand field spectra of the 5G 6 ← 5I 8 hypersensitive transition and their similarities with the known spectra of holmium chloro-elpasolite. Smooth spectral changes with nearly invariant molar absorptivities (between 30 and 40 L mol -1 cm -1) are observed upon melting YCl 3 and α-TbCl 3 which indicate that most probably the Ho 3+ is in 6-fold distorted octahedral coordination in both compounds and both phases. Drastic spectral changes are observed alongside the α-TbCl 3 to β-TbCl 3 phase transition where the coordination is altered from six to eight and the molar absorptivity quadruples. The spectra of liquid Y(Ho)Cl 3 and Tb(Ho)Cl 3 are correlated to the spectra of liquid La(Ho)Cl 3 and Gd(Ho)Cl 3 and are attributed to the ligand field states of Ho 3+ in distorted octahedral geometries. In conjunction with the molar volumes of all RCl 3 (R = rare earth) liquids which are invariant and independent of R and with Raman spectroscopic measurements for the same systems, a common possible structure of the rare earth chloride liquids is deduced and proposed.

  7. Composite electrolytes of polyethylene oxides/garnets interfacially wetted by ionic liquid for room-temperature solid-state lithium battery

    Science.gov (United States)

    Huo, Hanyu; Zhao, Ning; Sun, Jiyang; Du, Fuming; Li, Yiqiu; Guo, Xiangxin

    2017-12-01

    Paramount attention has been paid on solid polymer electrolytes due to their potential in enhancement of energy density as well as improvement of safety. Herein, the composite electrolytes consisting of Li-salt-free polyethylene oxides and 200 nm-sized Li6.4La3Zr1.4Ta0.6O12 particles interfacially wetted by [BMIM]TF2N of 1.8 μL cm-2 have been prepared. Such wetted ionic liquid remains the solid state of membrane electrolytes and decreases the interface impedance between the electrodes and the electrolytes. There is no release of the liquid phase from the PEO matrix when the pressure of 5.0 × 104 Pa being applied for 24 h. The interfacially wetted membrane electrolytes show the conductivity of 2.2 × 10-4 S cm-1 at 20 °C, which is one order of magnitude greater than that of the membranes without the wetted ionic liquids. The conduction mechanism is related to a large number of lithium ions releasing from Li6.4La3Zr1.4Ta0.6O12 particles and the improved conductive paths along the ion-liquid-wetted interfaces between the polymer matrix and ceramic grains. When the membranes being used in the solid-state LiFePO4/Li and LiFe0.15Mn0.85PO4/Li cells at 25 °C, the excellent rate capability and superior cycle stability has been shown. The results provide a new prospect for solid polymer electrolytes used for room-temperature solid-state lithium batteries.

  8. Ionic liquid processing of cellulose.

    Science.gov (United States)

    Wang, Hui; Gurau, Gabriela; Rogers, Robin D

    2012-02-21

    Utilization of natural polymers has attracted increasing attention because of the consumption and over-exploitation of non-renewable resources, such as coal and oil. The development of green processing of cellulose, the most abundant biorenewable material on Earth, is urgent from the viewpoints of both sustainability and environmental protection. The discovery of the dissolution of cellulose in ionic liquids (ILs, salts which melt below 100 °C) provides new opportunities for the processing of this biopolymer, however, many fundamental and practical questions need to be answered in order to determine if this will ultimately be a green or sustainable strategy. In this critical review, the open fundamental questions regarding the interactions of cellulose with both the IL cations and anions in the dissolution process are discussed. Investigations have shown that the interactions between the anion and cellulose play an important role in the solvation of cellulose, however, opinions on the role of the cation are conflicting. Some researchers have concluded that the cations are hydrogen bonding to this biopolymer, while others suggest they are not. Our review of the available data has led us to urge the use of more chemical units of solubility, such as 'g cellulose per mole of IL' or 'mol IL per mol hydroxyl in cellulose' to provide more consistency in data reporting and more insight into the dissolution mechanism. This review will also assess the greenness and sustainability of IL processing of biomass, where it would seem that the choices of cation and anion are critical not only to the science of the dissolution, but to the ultimate 'greenness' of any process (142 references).

  9. Single-Molecule Electrochemical Gating in Ionic Liquids

    DEFF Research Database (Denmark)

    Kay, Nicola J.; Higgins, Simon J.; Jeppesen, Jan O.

    2012-01-01

    The single-molecular conductance of a redox active molecular bridge has been studied in an electrochemical single-molecule transistor configuration in a room-temperature ionic liquid (RTIL). The redox active pyrrolo-tetrathiafulvalene (pTTF) moiety was attached to gold contacts at both ends through...... −(CH2)6S– groups, and gating of the redox state was achieved with the electrochemical potential. The water-free, room-temperature, ionic liquid environment enabled both the monocationic and the previously inaccessible dicationic redox states of the pTTF moiety to be studied in the in situ scanning...... relaxation. Using this view, reorganization energies of ∼1.2 eV have been estimated for both the first and second redox transitions for the pTTF bridge in the 1-butyl-3-methylimidazolium trifluoromethanesulfonate (BMIOTf) ionic liquid environment. By contrast, in aqueous environments, a much smaller...

  10. Synthesis and properties of chiral ammonium-based ionic liquids.

    Science.gov (United States)

    Pernak, Juliusz; Feder-Kubis, Joanna

    2005-07-18

    New chiral ammonium-based ionic liquids containing the (1R,2S,5R)-(-)-menthyl group can be easily and efficiently prepared under ambient conditions. The preparation and characterization of trialkyl[(1R,2S,5R)-(-)-menthoxymethyl]ammonium salts is reported. The salts have been demonstrated to be air- and moisture-stable under ambient conditions and can be readily used in a variety of standard experimental procedures. The single-crystal X-ray structure of butyldimethyl[(1R,2S,5R)-(-)-menthoxymethyl]ammonium chloride has been determined. The chiral, room-temperature ionic liquids have been characterized by physical properties such as specific rotation, density, viscosity, thermal degradation, and glass transition temperature. Trialkyl[(1R,2S,5R)-(-)-menthoxymethyl]ammonium chloride prototype ionic liquids have also been found to exhibit strong antimicrobial and high antielectrostatic activities.

  11. Supported ionic liquid-phase (SILP) catalysis

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Wasserscheid, P.

    2005-01-01

    The concept of supported ionic liquid-phase (SILP) catalysis has been demonstrated for gas- and liquid-phase continuous fixed-bed reactions using rhodium phosphine catalyzed hydroformylation of propene and 1-octene as examples. The nature of the support had important influence on both the catalytic...

  12. An efficient ultrasound assisted approach for the impregnation of room temperature ionic liquid onto Dowex 1×8 resin matrix and its application toward the enhanced adsorption of chromium (VI).

    Science.gov (United States)

    Kalidhasan, S; Kumar, A Santhana Krishna; Rajesh, Vidya; Rajesh, N

    2012-04-30

    The work discussed in this paper is based on the utilization of ultrasound in conjunction with an ionic liquid (Aliquat 336) impregnated Dowex 1×8 resin for the effective adsorption of chromium. Ionic liquids are known for their selectivity toward metal extraction and ultrasonic medium offers efficient energy transfer for impregnating the ionic liquid in the resin matrix. The molecular interaction between the ionic liquid impregnated resin and chromium was studied through various physicochemical and spectroscopic techniques. The influence of various analytical parameters on the adsorption of Cr(VI) such as pH, adsorbent dosage, temperature and interference of foreign ions was studied in detail. Chromium (VI) was quantitatively adsorbed in the pH range of 3.5-4, with a high adsorption capacity of 230.9 mg g(-1) in conformity with the Langmuir isotherm model. The study of thermodynamic parameters showed that the adsorption process is exothermic and spontaneous. The adsorbent could be regenerated using 1 mol L(-1) HCl-0.28 mol L(-1) ascorbic acid mixture. Chromium could be effectively detoxified from an industrial effluent and finally the developed method was validated with the analysis of a certified reference material (BCR-715). The obtained results indicated that the ultrasonic assisted impregnation of the room temperature ionic liquid significantly enhances and improves the removal efficiency of Cr(VI). Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Inorganic materials synthesis in ionic liquids

    Directory of Open Access Journals (Sweden)

    Christoph Janiak

    2014-01-01

    Full Text Available The field of "inorganic materials from ionic liquids" (ILs is a young and dynamically growing research area for less than 10 years. The ionothermal synthesis in ILs is often connected with the preparation of nanomaterials, the use of microwave heating and in part also ultrasound. Inorganic material synthesis in ILs allows obtaining phases which are not accessible in conventional organic or aqueous solvents or with standard methods of solid-state chemistry or under such mild conditions. Cases at hand include "ligand-free" metal nanoparticles without added stabilizing capping ligands, inorganic or inorganic-organic hybrid solid-state compounds, large polyhedral clusters and exfoliated graphene from low-temperature synthesis. There are great expectations that ILs open routes towards new, possibly unknown, inorganic materials with advantageous properties that cannot (or only with great difficulty be made via conventional processes.

  14. Ionic Liquids as Advanced Lubricant Fluids

    Directory of Open Access Journals (Sweden)

    Francisco-José Carrión

    2009-08-01

    Full Text Available Ionic liquids (ILs are finding technological applications as chemical reaction media and engineering fluids. Some emerging fields are those of lubrication, surface engineering and nanotechnology. ILs are thermally stable, non-flammable highly polar fluids with negligible volatility, these characteristics make them ideal candidates for new lubricants under severe conditions, were conventional oils and greases or solid lubricants fail. Such conditions include ultra-high vacuum and extreme temperatures. Other very promising areas which depend on the interaction between IL molecules and material surfaces are the use of ILs in the lubrication of microelectromechanic and nanoelectromechanic systems (MEMS and NEMS, the friction and wear reduction of reactive light alloys and the modification of nanophases.

  15. Key Developments in Ionic Liquid Crystals

    Directory of Open Access Journals (Sweden)

    Alexandra Alvarez Fernandez

    2016-05-01

    Full Text Available Ionic liquid crystals are materials that combine the classes of liquid crystals and ionic liquids. The first one is based on the multi-billion-dollar flat panel display industry, whilst the latter quickly developed in the past decades into a family of highly-tunable non-volatile solvents. The combination yields materials with a unique set of properties, but also with many challenges ahead. In this review, we provide an overview of the key concepts in ionic liquid crystals, particularly from a molecular perspective. What are the important molecular parameters that determine the phase behavior? How should they be introduced into the molecules? Finally, which other tools does one have to realize specific properties in the material?

  16. An electrochemical alternative strategy to the synthesis of {beta}-lactams. Part 3 [1]. Room-temperature ionic liquids vs molecular organic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Sotgiu, G.; Orsini, M. [Dip. Elettronica Applicata, Universita di Roma Tre, via Vasca Navale 84, I-00146 Roma (Italy); Chiarotto, I.; Feroci, M.; Inesi, A. [Dip. Ingegneria Chimica, Materiali, Materie Prime e Metallurgia, Universita ' ' La Sapienza' ' , via Castro Laurenziano, 7, I-00161 Roma (Italy); Rossi, L. [Dip. Chimica, Ingegneria Chimica e Materiali, Universita degli Studi, I-67040, Monteluco di Roio, L' Aquila (Italy)

    2008-11-15

    Electrochemically induced cyclization of bromoamides to {beta}-lactams has been achieved in room-temperature ionic liquids (RTILs). The use of volatile, organic solvents (VOCs) and of supporting electrolytes may be avoided. Proton exchange reaction between amide substrates and suitable electrogenerated bases gives rise to a C{sub 4} carbanion which undergoes cyclization to {beta}-lactam via intramolecular nucleophilic substitution (C{sub 3}-C{sub 4} bond formation). {beta}-Lactams have been isolated in good to elevated yields. The 'non innocent' nature of the RTILs (imidazolium-based salts) is considered. Proton exchange reaction between N-dialkylimidazolium cation and EGB yielding N-heterocyclic carbene is discussed. (author)

  17. Iron carbide nanoparticles growth in room temperature ionic liquids [C{sub n}-MIM][BF{sub 4}] (n = 12, 16)

    Energy Technology Data Exchange (ETDEWEB)

    Lartigue, Lenaiec; Long, Jerome; Dumail, Xavier [Universite Montpellier II, Institut Charles Gerhardt Montpellier, UMR5253, Chimie Moleculaire et Organisation du Solide (France); Nikitenko, Sergey I.; Cau, Camille [Institut de Chimie Separative de Marcoule, UMR 5257, Centre de Marcoule (France); Guari, Yannick, E-mail: yannick.guari@um2.fr [Universite Montpellier II, Institut Charles Gerhardt Montpellier, UMR5253, Chimie Moleculaire et Organisation du Solide (France); Stievano, Lorenzo; Sougrati, Moulay T. [Universite Montpellier II, Institut Charles Gerhardt Montpellier, UMR 5253, Agregats, Interfaces et Materiaux pour l' Energie (France); Guerin, Christian [Universite Montpellier II, Institut Charles Gerhardt Montpellier, UMR5253, Chimie Moleculaire et Organisation du Solide (France); Sangregorio, Claudio [CNR-ISTM (Italy); Larionova, Joulia [Universite Montpellier II, Institut Charles Gerhardt Montpellier, UMR5253, Chimie Moleculaire et Organisation du Solide (France)

    2013-04-15

    The thermal decomposition of Fe{sub x}(CO){sub y} precursors for the synthesis of nanoparticles of iron carbides and their superstructures with sizes ranging from 2.8 to 15.1 nm is developed using imidazolium-based ionic liquids as solvents, stabilizers, and carbon source. A study of the influence of some synthesis parameters such as the heating temperature, nature, and concentration of the iron carbonyl precursor and chain length of the N-alkyl substituent on the imidazolium ring on the size and organization of the iron carbide nanoparticles is presented. These iron carbides nano-objects were characterized by infra-red spectroscopy, transmission electronic microscopy, powder X-ray diffraction, Mossbauer spectroscopy, and magnetic analyses.

  18. Preparation of room temperature ionic liquids based on aliphatic onium cations and asymmetric amide anions and their electrochemical properties as a lithium battery electrolyte

    Science.gov (United States)

    Matsumoto, Hajime; Sakaebe, Hikari; Tatsumi, Kuniaki

    The physical and electrochemical properties of room temperature ionic liquids (RTILs) based on asymmetric amide anions (TSAC: 2,2,2-trifluoro- N-(trifluoromethylsulfonyl)acetamide, C1C2: N-(trifluoromethylsulfonyl)pentafluoroethylsulfonamide) and aliphatic onium cations, such as ammonium, phosphonium, and sulfonium, were reported. The melting point of the C1C2 salts decreased compared to the corresponding TFSI salts (TFSI: bis(trifluoromethylsulfonyl)imide), however, the viscosity was about twice that of the TFSI salts. Relatively low viscosity RTILs based on aliphatic onium cations could be prepared using the TSAC anion and tetraalkylammonium cation containing an alkoxy group. The linear sweep voltammogram of these RTILs with and without Li-TFSI were investigated in order to estimate the electrochemical windows and possible use as a lithium battery electrolyte.

  19. Brønsted Acid Ionic Liquids (BAILs) as Efficient and Recyclable Catalysts in the Conversion of Glycerol to Solketal at Room Temperature

    DEFF Research Database (Denmark)

    Gui, Zhenyou; Zahrtmann, Nanette; Shunmugavel, Saravanamurugan

    2016-01-01

    Brønsted acid ionic liquids (BAILs) have been prepared and applied for the first time - to the best of our knowledge - as efficient catalysts in the acetylation of glycerol with acetone to form solketal ((2,2-dimethyl-1,3-dioxolan-4-yl)methanol) at very mild reaction conditions (room temperature......) and short reaction times. The BAILs showed a superior catalytic performance in terms of both conversion and selectivity compared to the common mineral acid methanesulfonic acid as well as to other reported homogeneous and heterogeneous catalysts. Catalyst reusability was demonstrated with one of the BAILs...... (BAIL-1), which was recovered and reused by a simple procedure in four consecutive reaction runs without any loss of catalytic activity and selectivity. Thus, the BAILs combine the advantages of both homogeneous and heterogeneous catalysis with respect to excellent conversion and selectivity as well...

  20. A Simple Guiding Principle for the Temperature Dependence of the Solubility of Light Gases in Imidazolium-based Ionic Liquids Derived from Molecular Simulations

    CERN Document Server

    Kerlé, Daniela; Ludwig, Ralf; Wohlrab, Sebastian; Paschek, Dietmar

    2015-01-01

    We have determined the temperature dependence of the solvation behavior of a large collection of light gases in imidazolium-based Ionic Liquids (ILs) with the help of extensive molecular dynamics simulations. The solubility of molecular hydrogen, oxygen, nitrogen, methane, krypton, argon, neon and carbon dioxide in the imidazolium based ILs of type 1-n-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C$_n$mim][NTf$_2$]) with varying chain lengths $n\\!=\\!2,4,6,8$ are computed for a temperature range between $300\\,\\mbox{K}$ and $500\\,\\mbox{K}$ at $1\\,\\mbox{bar}$. By applying Widom's particle insertion technique and Bennet's overlapping distribution method, we are able to determine the temperature dependent solvation free energies for those selected light gases in simulated imidazolium based ILs with high statistical accuracy. Our simulations show that the magnitude of the solvation free energy of a gas molecule at a chosen reference temperature and its temperature-derivatives are intimately related...

  1. Trace mercury determination in drinking and natural water samples by room temperature ionic liquid based-preconcentration and flow injection-cold vapor atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Martinis, Estefania M.; Berton, Paula [Laboratory of Environmental Research and Services of Mendoza (LISAMEN), (CCT - CONICET - Mendoza), Av. Ruiz Leal S/N Parque General San Martin, CC. 131, M 5502 IRA Mendoza (Argentina); Olsina, Roberto A. [INQUISAL-CONICET, Departamento de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, San Luis (Argentina); Altamirano, Jorgelina C. [Laboratory of Environmental Research and Services of Mendoza (LISAMEN), (CCT - CONICET - Mendoza), Av. Ruiz Leal S/N Parque General San Martin, CC. 131, M 5502 IRA Mendoza (Argentina); Instituto de Ciencias Basicas, Universidad Nacional de Cuyo, Mendoza (Argentina); Wuilloud, Rodolfo G., E-mail: rwuilloud@lab.cricyt.edu.ar [Laboratory of Environmental Research and Services of Mendoza (LISAMEN), (CCT - CONICET - Mendoza), Av. Ruiz Leal S/N Parque General San Martin, CC. 131, M 5502 IRA Mendoza (Argentina); Instituto de Ciencias Basicas, Universidad Nacional de Cuyo, Mendoza (Argentina)

    2009-08-15

    A liquid-liquid extraction procedure (L-L) based on room temperature ionic liquid (RTIL) was developed for the preconcentration and determination of mercury in different water samples. The analyte was quantitatively extracted with 1-butyl-3-methylimidazolium hexafluorophosphate ([C{sub 4}mim][PF{sub 6}]) under the form of Hg-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (Hg-5-Br-PADAP) complex. A volume of 500 {mu}l of 9.0 mol L{sup -1} hydrochloric acid was used to back-extract the analyte from the RTIL phase into an aqueous media prior to its analysis by flow injection-cold vapor atomic absorption spectrometry (FI-CV-AAS). A preconcentration factor of 36 was achieved upon preconcentration of 20 mL of sample. The limit of detection (LOD) obtained under the optimal conditions was 2.3 ng L{sup -1} and the relative standard deviation (RSD) for 10 replicates at 1 {mu}g L{sup -1} Hg{sup 2+} was 2.8%, calculated with peaks height. The method was successfully applied to the determination of mercury in river, sea, mineral and tap water samples and a certified reference material (CRM).

  2. Polysiloxane ionic liquids as good solvents for β-cyclodextrin-polydimethylsiloxane polyrotaxane structures

    Directory of Open Access Journals (Sweden)

    Narcisa Marangoci

    2012-09-01

    Full Text Available An ionic liquid based on polydimethylsiloxane with imidazolium salt brushes was synthesized as a good solvent for β-cyclodextrin-polydimethylsiloxane rotaxane. As expected the PDMS-Im/Br ionic liquid had a liquid-like non-Newtonian behavior with rheological parameters dependent on frequency and temperature. The addition of rotaxane to the ionic liquid strengthened the non-Newtonian character of the sample and a type of stable liquid-like network was formed due to the contribution of weak ionic interactions. The structure is stable in the 20 to 80 °C domain as proved by the oscillatory and rotational rheological tests.

  3. Enzymatic isomerization of glucose and xylose in ionic liquids

    DEFF Research Database (Denmark)

    Ståhlberg, Tim Johannes Bjarki; Woodley, John; Riisager, Anders

    2012-01-01

    Glucose isomerase has been found for the first time to catalyze the isomerization of glucose to fructose in the ionic liquid N, N-dibutylethanolammonium octanoate (DBAO). Isomerization was achieved at temperatures of 60-80 degrees C although a substantial amount of mannose was formed at elevated...

  4. Determination of Lipophilic Extractives in Ionic Liquid Extracts of ...

    African Journals Online (AJOL)

    Determination of Lipophilic Extractives in Ionic Liquid Extracts of Eucalyptus Pulp by Gas Chromatography - Mass Spectrometry. ... The effect of temperature of the added precipitating solvent during cellulose regeneration on the recovery of extractives was also studied. Recovery of extractives increased with increasing ...

  5. Synthesis and testing of hypergolic ionic liquids for chemical propulsion

    Science.gov (United States)

    Stovbun, S. V.; Shchegolikhin, A. N.; Usachev, S. V.; Khomik, S. V.; Medvedev, S. P.

    2017-06-01

    Synthesis of new highly energetic ionic liquids (ILs) is described, and their hypergolic ignition properties are tested. The synthesized ILs combine the advantages of conventional rocket propellants with the energy characteristics of acetylene derivatives. To this end, N-alkylated imidazoles (alkyl = ethyl, butyl) have been synthesized and alkylated with propargyl bromide. The desired ionic liquids have been produced by metathesis using Ag dicyanamide. Modified hypergolic drop tests with white fuming nitric acid have been performed for N-ethyl (IL-1) and N-butyl propargylimidazolium (IL-2) ionic liquids. In the modified drop tests, high-speed shadowgraph imaging is used to visualize the process, and the temperature rise due to ignition is monitored with a two-color photodetector. It is shown that the ignition delay is shorter for IL-1 as compared to IL-2. The ignition of IL-1 occurs in two stages, whereas the combustion of IL-2 proceeds smoothly without secondary flashes.

  6. Functional ionic liquids; Funktionelle ionische Fluessigkeiten

    Energy Technology Data Exchange (ETDEWEB)

    Baecker, Tobias

    2012-07-01

    In the thesis at hand, new functional ionic liquids were investigated. Main focus was attended to their structure property relations and the structural features leading to a decrease of the melting point. New compounds of the type 1-butyl-3-methylimidazolium tris(N,Ndialkyldithiocarbamato) uranylate with variously substituated dithiocarbamato ligands were synthesized and characterized. Ligands with asymmetrical substitution pattern proved to be most suitable for ionic liquid formation. The single-crystal X-ray structures revealed the interactions in the solid state. Here, the first spectroscopic investigation of the U-S bond in sulfur donated uranyl complexes, up to now only observed in single-crystal X-ray structures, is presented, and the participation of the uranium f-orbitals is shown by theoretical calculations. Electrochemical investigations showed the accessibility of the respective U{sup V}O{sub 2}{sup +} compounds. As well, ionic liquids with [FeCl{sub 4}]{sup -} and [Cl{sub 3}FeOFeCl{sub 3}]{sup 2-} as anion were synthesized. Both of these anions contain high-spin Fe(III) centres in distorted tetrahedral environment, but exhibit different magnetic behaviour. The tetrachloroferrates show the usual paramagnetism, the m-oxobis(trichloroferrate) exhibits unexpectedly strong antiferromagnetic coupling, as was observed by NMR experiments and susceptibility measurements. To investigate structure-property relations in functionalized ionic liquids, a set of protic, primary alkylammonium and aprotic, quarternary trimethylalkylammonium based ionic liquids was synthesized, and characterized. The length of the alkyl chain was systematically varied, and all compounds were synthesized with and without hydroxyl group, as well as formate and bis(triflyl)amide salts, aiming at getting insight into the influence of the different structure parts on the respective ionic liquid's properties.

  7. Femtosecond Raman-Induced Kerr Effect Study of Temperature-Dependent Intermolecular Dynamics in Imidazolium-Based Ionic Liquids: Effects of Anion Species and Cation Alkyl Groups.

    Science.gov (United States)

    Kakinuma, Shohei; Ishida, Tateki; Shirota, Hideaki

    2017-01-12

    The temperature dependence of the intermolecular vibrational dynamics in imidazolium-based ionic liquids (ILs) with 10 different anions was studied by femtosecond Raman-induced Kerr effect spectroscopy. For all ILs investigated in this study, the intensity in the low-frequency region below 50 cm-1 increases, and the spectral density in the high-frequency region above 80 cm-1 decreases (and shows a redshift) with increasing temperature. The first phenomenon would be attributed to the activation of the translational vibrational motions, whereas the second one is ascribed to the slowing librational motion of the imidazolium ring with increasing temperature. Calculated spectra of the density of states for the intermolecular vibrations of 1-butyl-3-methylimidazolium hexafluorophosphate, which is one of the experiment samples studied here, obtained by molecular dynamics simulation agreed well with the experimental results and confirmed the spectral assignments. When we compared the difference spectra between spectra measured at various temperatures and the spectrum measured at 293 K, a clear difference was found in the ∼50 cm-1 region of the Kerr spectra of 1-butyl-3-methylimidazolium thiocyanate and 1-butyl-3-methylimidazolium dicyanamide from those of the other ILs. The difference might have originated from the librational motions of the corresponding anions. We also compared the temperature-dependent Kerr spectra of hexafluorophosphate salts of 1-butyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, and 1-heptyl-3-methylimidazolium cations. These ILs showed a similar temperature dependence, which was not affected by the alkyl group length. The temperature-dependent viscosities and glass transition temperatures of the ILs were also estimated to determine their fragilities.

  8. Characterization and parametrical study of Rh-TPPTS supported ionic liquid phase (SILP) catalysts for ethylene hydroformylation

    DEFF Research Database (Denmark)

    Hanh, Nguyen Thi Ha; Duc, Duc Truong; Thang, Vu Dao

    2012-01-01

    , BET surface area and pore morphology of the catalysts depended on the content of ionic liquid. Hence, catalysts with high ionic liquid loading content showed deactivation at high reaction temperatures, possibly caused by redistribution of ionic liquid out of the pores under these conditions. (C) 2012...

  9. An efficient ultrasound assisted approach for the impregnation of room temperature ionic liquid onto Dowex 1 Multiplication-Sign 8 resin matrix and its application toward the enhanced adsorption of chromium (VI)

    Energy Technology Data Exchange (ETDEWEB)

    Kalidhasan, S.; Santhana Krishna Kumar, A. [Department of Chemistry, Birla Institute of Technology and Science (BITS), Pilani-Hyderabad Campus, Jawahar Nagar, Shameerpet Mandal, R. R. Dist 500 078, AP (India); Vidya Rajesh [Department of Biological Sciences, Birla Institute of Technology and Science (BITS), Pilani-Hyderabad Campus, Jawahar Nagar, Shameerpet Mandal, R. R. Dist 500 078, AP (India); Rajesh, N., E-mail: nrajesh05@gmail.com [Department of Chemistry, Birla Institute of Technology and Science (BITS), Pilani-Hyderabad Campus, Jawahar Nagar, Shameerpet Mandal, R. R. Dist 500 078, AP (India)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer Ultrasound assisted impregnation of an ionic liquid in a Dowex resin matrix is studied through various physicochemical and spectroscopic techniques. Black-Right-Pointing-Pointer Chromium is adsorbed with a high adsorption capacity of 230.9 mg g{sup -1}. Black-Right-Pointing-Pointer The adsorbent is regenerated using HCl-ascorbic acid mixture. Black-Right-Pointing-Pointer Chromium could be effectively detoxified from an industrial effluent and the developed method was validated with the analysis of a certified reference material. - Abstract: The work discussed in this paper is based on the utilization of ultrasound in conjunction with an ionic liquid (Aliquat 336) impregnated Dowex 1 Multiplication-Sign 8 resin for the effective adsorption of chromium. Ionic liquids are known for their selectivity toward metal extraction and ultrasonic medium offers efficient energy transfer for impregnating the ionic liquid in the resin matrix. The molecular interaction between the ionic liquid impregnated resin and chromium was studied through various physicochemical and spectroscopic techniques. The influence of various analytical parameters on the adsorption of Cr(VI) such as pH, adsorbent dosage, temperature and interference of foreign ions was studied in detail. Chromium (VI) was quantitatively adsorbed in the pH range of 3.5-4, with a high adsorption capacity of 230.9 mg g{sup -1} in conformity with the Langmuir isotherm model. The study of thermodynamic parameters showed that the adsorption process is exothermic and spontaneous. The adsorbent could be regenerated using 1 mol L{sup -1} HCl-0.28 mol L{sup -1} ascorbic acid mixture. Chromium could be effectively detoxified from an industrial effluent and finally the developed method was validated with the analysis of a certified reference material (BCR-715). The obtained results indicated that the ultrasonic assisted impregnation of the room temperature ionic liquid significantly

  10. Catalytic Ionic-Liquid Membranes: The Convergence of Ionic-Liquid Catalysis and Ionic-Liquid Membrane Separation Technologies.

    Czech Academy of Sciences Publication Activity Database

    Izák, Pavel; Bobbink, F.D.; Hulla, M.; Klepic, M.; Friess, K.; Hovorka, Š.; Dyson, P.J.

    2018-01-01

    Roč. 83, č. 1 (2018), s. 7-18 ISSN 2192-6506 R&D Projects: GA ČR(CZ) GA17-00089S; GA ČR GA17-05421S Institutional support: RVO:67985858 Keywords : heterogeneous catalysis * ionic liquids * membranes Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.797, year: 2016

  11. Task-specific microextractions using ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Qichao; Anderson, Jared L. [University of Toledo, Department of Chemistry, Toledo, OH (United States)

    2011-06-15

    Ionic liquids (ILs) have been the focus of many scientific investigations including the field of analytical microextractions. ILs have many advantages over traditional organic solvents making them excellent candidates as extraction media for a variety of microextraction techniques. Many physical properties of ILs can be varied, and the structural design and make-up can be tuned to impart desired functionality for enhancement of analyte extraction selectivity, efficiency, and sensitivity. This paper provides a brief overview of ionic liquids and highlights trends in three important sample-preparation techniques, namely, single drop microextraction, solid-phase microextraction, and dispersive liquid-liquid microextraction in terms of performing task-specific extractions using these highly versatile solvents. (orig.)

  12. Physical Chemistry of Reaction Dynamics in Ionic Liquid

    Energy Technology Data Exchange (ETDEWEB)

    Maroncelli, Mark [Pennsylvania State Univ., University Park, PA (United States)

    2016-10-02

    Work completed over the past year mainly involves finishing studies related to solvation dynamics in ionic liquids, amplifying and extending our initial PFG-NMR work on solute diffusion, and learning how to probe rotational dynamics in ionic liquids.

  13. Applications of ionic liquids in polymer science and technology

    CERN Document Server

    2015-01-01

    This book summarizes the latest knowledge in the science and technology of ionic liquids and polymers in different areas. Ionic liquids (IL) are actively being investigated in polymer science and technology for a number of different applications. In the first part of the book the authors present the particular properties of ionic liquids as speciality solvents. The state-of-the art in the use of ionic liquids in polymer synthesis and modification reactions including polymer recycling is outlined. The second part focuses on the use of ionic liquids as speciality additives such as plasticizers or antistatic agents.  The third part examines the use of ionic liquids in the design of functional polymers (usually called polymeric ionic liquids (PIL) or poly(ionic liquids)). Many important applications in diverse scientific and industrial areas rely on these polymers, like polymer electrolytes in electrochemical devices, building blocks in materials science, nanocomposites, gas membranes, innovative anion sensitive...

  14. Redox-active Crosslinkable Poly(ionic liquid)s

    NARCIS (Netherlands)

    Sui, Xiaofeng; Hempenius, Mark A.; Vancso, Gyula J.

    2012-01-01

    The synthesis of a new class of cross-linkable redox-responsive poly(ferrocenylsilane)-based poly(ionic liquid)s (PFS-PILs) is reported. PFS-PILs self-cross-link at low concentrations into nanogels or form macroscopic hydrogel networks at higher concentrations. PFS-PILs proved to be efficient

  15. Reactions of Starch in Ionic Liquids

    Science.gov (United States)

    We found that starches are found to be soluble at 80 ºC in ionic liquids such as 1-butyl-3-methylimidazolium chloride (BMIMCl) and 1-butyl-3-methylimidazolium dicyanamide (BMIMdca) in concentration up to 10% (w/w). Higher concentrations of biopolymers in these novel solvents resulted in solutions w...

  16. Structure and lifetimes in ionic liquids and their mixtures.

    Science.gov (United States)

    Gehrke, Sascha; von Domaros, Michael; Clark, Ryan; Hollóczki, Oldamur; Brehm, Martin; Welton, Tom; Luzar, Alenka; Kirchner, Barbara

    2017-09-21

    With the aid of molecular dynamics simulations, we study the structure and dynamics of different ionic liquid systems, with focus on hydrogen bond, ion pair and ion cage formation. To do so, we report radial distribution functions, their number integrals, and various time-correlation functions, from which we extract well-defined lifetimes by means of the reactive flux formalism. We explore the influence of polarizable force fields vs. non-polarizable ones with downscaled charges (±0.8) for the example of 1-butyl-3-methylimidazolium bromide. Furthermore, we use 1-butyl-3-methylimidazolium trifluoromethanesulfonate to investigate the impact of temperature and mixing with water as well as with the chloride ionic liquid. Smaller coordination numbers, larger distances, and tremendously accelerated dynamics are observed when the polarizable force field is applied. The same trends are found with increasing temperature. Adding water decreases the ion-ion coordination numbers whereas the water-ion and water-water coordination is enhanced. A domain analysis reveals that the nonpolar parts of the ions are dispersed and when more water is added the water clusters increase in size. The dynamics accelerate in general upon addition of water. In the ionic liquid mixture, the coordination number around the cation changes between the two anions, but the number integrals of the cation around the anions remain constant and the dynamics slow down with increasing content of the chloride ionic liquid.

  17. Ionic Liquids and Poly(ionic liquid)s for Morphosynthesis of Inorganic Materials.

    Science.gov (United States)

    Gao, Min-Rui; Yuan, Jiayin; Antonietti, Markus

    2017-04-24

    Ionic liquids (ILs) are new, innovative ionic solvents with rich physicochemical properties and intriguing pre-organized solvent structures; these materials offer great potential to impact across versatile areas of scientific research, for example, synthetic inorganic chemistry. Recent use of ILs as precursors, templates, and solvents has led to inorganic materials with tailored sizes, dimensionalities, morphologies, and functionalities that are difficult to obtain, or even not accessible, by using conventional solvents. Poly(ionic liquid)s (PILs) polymerized from IL monomers also raise the prospect of modifying nucleation, growth, and crystallization of inorganic objects, shedding light on the synthesis of a wide range of new materials. Here we survey recent key progress in using ILs and PILs in the field of synthetic inorganic chemistry. As well as highlighting the unique features of ILs and PILs that enable advanced synthesis, the effects of adding other solvents to the final products, along with the emerging applications of the created inorganic materials will be discussed. We finally provide an outlook on several development opportunities that could lead to new advancements of this exciting research field. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Separation of benzene from alkanes using 1-ethyl-3-methylpyridinium ethylsulfate ionic liquid at several temperatures and atmospheric pressure: Effect of the size of the aliphatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Emilio J. [Departamento de Ingenieria Quimica, Universidad de Vigo, 36310 Vigo (Spain); Calvar, Noelia, E-mail: noecs@uvigo.e [Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Gomez, Elena [Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Dominguez, Angeles [Departamento de Ingenieria Quimica, Universidad de Vigo, 36310 Vigo (Spain)

    2010-01-15

    The ionic liquid 1-ethyl-3-methylpyridinium ethylsulfate, [EMpy][ESO{sub 4}], was studied for the separation of benzene from aliphatic hydrocarbons (octane or nonane) by solvent extraction through the determination of the (liquid + liquid) equilibrium (LLE) of the ternary systems: left braceoctane (1) + benzene (2) + [EMpy][ESO{sub 4}] (3)right brace and left bracenonane (1) + benzene (2) + [EMpy][ESO{sub 4}] (3)right brace at T = (283.15 and 298.15) K and atmospheric pressure. Binodal curves were determined using the 'cloud point' method, and tie-line compositions were obtained by density measurements. The values of selectivity and distribution coefficient, derived from the tie-line data, were used to decide if this ionic liquid can be used as potential solvent for the separation of benzene from aliphatic hydrocarbons using liquid extraction. These results were analyzed and compared to those previously reported for the systems left bracehexane + benzene + [EMpy][ESO{sub 4}]right brace and left braceheptane + benzene + [EMpy][ESO{sub 4}]right brace. The experimental results show that this ionic liquid is suitable for the extraction of benzene from mixtures containing octane and nonane. The consistency of tie-line data was ascertained by applying the Othmer-Tobias and Hand equations. The experimental results for the ternary systems were well correlated with the NRTL model. No literature data were found for the mixtures discussed in this paper.

  19. Ionic liquid containing hydroxamate and N-alkyl sulfamate ions

    Energy Technology Data Exchange (ETDEWEB)

    Friesen, Cody A.; Wolfe, Derek; Johnson, Paul Bryan

    2016-03-15

    Embodiments of the invention are related to ionic liquids and more specifically to ionic liquids used in electrochemical metal-air cells in which the ionic liquid includes a cation and an anion selected from hydroxamate and/or N-alkyl sulfamate anions.

  20. Ionic conductivity studies of gel polyelectrolyte based on ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Cha, E.H. [The Faculty of Liberal Arts (Chemistry), Hoseo University, Asan Choongnam 336-795 (Korea); Lim, S.A. [Functional Proteomics Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea); Park, J.H. [Department of Herbal Medicine, Hoseo University, Asan Choongnam 336-795 (Korea); Kim, D.W. [Department of Chemical Technology, Han Bat National University, Daejon 305-719 (Korea); Macfarlane, D.R. [School of Chemistry, Monash University, Clayton, Vic. 3800 (Australia)

    2008-04-01

    Novel lithium polyelectrolyte-ionic liquids have been prepared and characterized of their properties. Poly(lithium 2-acrylamido-2-methyl propanesulfonate) (PAMPSLi) and its copolymer with N-vinyl formamide (VF) also has been prepared as a copolymer. 1-Ethyl-3-methylimidazolium tricyanomethanide (emImTCM) and N,N-dimethyl-N-propyl-N-butyl ammonium tricyanomethanide (N{sub 1134}TCM) which are chosen because of the same with the anion of ionic liquid were prepared. The ionic conductivity of copolymer system (PAMPSLi/PVF/emImTCM: 5.43 x 10{sup -3} S cm{sup -1} at 25 C) exhibits about over four times higher than that of homopolymer system (PAMPSLi/emImTCM: 1.28 x 10{sup -3} S cm{sup -1} at 25 C). Introduction of vinyl formamide into the copolymer type can increase the dissociation of the lithium cations from the polymer backbone. The ionic conductivity of copolymer with emImTCM (PAMPSLi/PVF/emImTCM) exhibits the higher conductivity than that of PAMPSLi/PVF/N{sub 1134}TCM (2.48 x 10{sup -3} S cm{sup -1}). Because of using the polymerizable anion it is seen to maintain high flexibility of imidazolium cation effectively to exhibit the higher conductivity. And also the viscosity of emImTCM (19.56 cP) is lower than that of N{sub 1134}TCM (28.61 cP). Low viscosity leads to a fast rate of diffusion of redox species. (author)

  1. Ionic liquids-mediated interactions between nanorods

    Science.gov (United States)

    Yu, Zhou; Zhang, Fei; Huang, Jingsong; Sumpter, Bobby G.; Qiao, Rui

    2017-10-01

    Surface forces mediated by room-temperature ionic liquids (RTILs) play an essential role in diverse applications including self-assembly, lubrication, and electrochemical energy storage. Therefore, their fundamental understanding is critical. Using molecular simulations, we study the interactions between two nanorods immersed in model RTILs at rod-rod separations where both structural and double layer forces are important. The interaction force between neutral rods oscillates as the two rods approach each other, similar to the classical structural forces. Such oscillatory force originates from the density oscillation of RTILs near each rod and is affected by the packing constraints imposed by the neighboring rods. The oscillation period and decay length of the oscillatory force are mainly dictated by the ion density distribution near isolated nanorods. When charges are introduced on the rods, the interaction force remains short-range and oscillatory, similar to the interactions between planar walls mediated by some protic RTILs reported earlier. Nevertheless, introducing net charges to the rods greatly changes the rod-rod interactions, e.g., by delaying the appearance of the first force trough and increasing the oscillation period and decay length of the interaction force. The oscillation period and decay length of the oscillatory force and free energy are commensurate with those of the space charge density near an isolated, charged rod. The free energy of rod-rod interactions reaches local minima (maxima) at rod-rod separations when the space charges near the two rods interfere constructively (destructively). The insight on the short-range interactions between nanorods in RTILs helps guide the design of novel materials, e.g., ionic composites based on rigid-rod polyanions and RTILs.

  2. Physically Gelled Room-Temperature Ionic Liquid-Based Composite Membranes for CO2/N-2 Separation: Effect of Composition and Thickness on Membrane Properties and Performance

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, PT; Voss, BA; Wiesenauer, EF; Gin, DL; Nobe, RD

    2013-07-03

    An aspartame-based, low molecular-weight organic gelator (LMOG) was used to form melt-infused and composite membranes with two different imidazolium-based room-temperature ionic liquids (RTILs) for CO2 separation from N-2. Previous work demonstrated that LMOGs can gel RTILs at low, loading levels, and this aspartame-based LMOG was selected because it has been reported to gel a large number of RTILs. The imidazolium-based RTILs were used because of their inherent good properties for CO2/light gas separations. Analysis of the resulting bulk RTIL/LMOG physical gels showed that these materials have high sol-gel transition temperatures (ca. 135 degrees C) suitable for flue gas applications. Gas permeabilities and burst pressure measurements of thick, melt infused membranes revealed a trade-off between high CO2 permeabilities and good mechanical stability as a function of the LMOG loading. Defect-free, composite membranes of the gelled RTILs were successfully fabricated by choosing an appropriate porous membrane support (hydrophobic PTFE) using a suitable coating technique (roller coating). The thicknesses of the applied composite gel layers ranged from 10.3 to 20.7 mu m, which represents an order of magnitude decrease in active layer thickness, compared to the original melt-infused gel RTIL membranes.

  3. Hyperthermostable Thermotoga maritima xylanase XYN10B shows high activity at high temperatures in the presence of biomass-dissolving hydrophilic ionic liquids.

    Science.gov (United States)

    Yu, Tianyi; Anbarasan, Sasikala; Wang, Yawei; Telli, Kübra; Aslan, Aşkın Sevinç; Su, Zhengding; Zhou, Yin; Zhang, Li; Iivonen, Piia; Havukainen, Sami; Mentunen, Tero; Hummel, Michael; Sixta, Herbert; Binay, Baris; Turunen, Ossi; Xiong, Hairong

    2016-07-01

    The gene of Thermotoga maritima GH10 xylanase (TmXYN10B) was synthesised to study the extreme limits of this hyperthermostable enzyme at high temperatures in the presence of biomass-dissolving hydrophilic ionic liquids (ILs). TmXYN10B expressed from Pichia pastoris showed maximal activity at 100 °C and retained 92 % of maximal activity at 105 °C in a 30-min assay. Although the temperature optimum of activity was lowered by 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc), TmXYN10B retained partial activity in 15-35 % hydrophilic ILs, even at 75-90 °C. TmXYN10B retained over 80 % of its activity at 90 °C in 15 % [EMIM]OAc and 15-25 % 1-ethyl-3-methylimidazolium dimethylphosphate ([EMIM]DMP) during 22-h reactions. [EMIM]OAc may rigidify the enzyme and lower V max. However, only minor changes in kinetic parameter K m showed that competitive inhibition by [EMIM]OAc of TmXYN10B is minimal. In conclusion, when extended enzymatic reactions under extreme conditions are required, TmXYN10B shows extraordinary potential.

  4. Changes in microstructure of two ammonium-based protic ionic liquids proved by in situ variable-temperature 1 H NMR spectroscopy: influence of anion.

    Science.gov (United States)

    Tang, Xiaochen; Xu, Yingjie; Zhu, Xiao; Lu, Yueqing

    2017-04-22

    In this work, changes in microstructure of two protic ionic liquids (PILs), namely n-butylammonium acetate (N4Ac) and n-butylammonium nitrate (N4NO3 ), are proved by in situ variable-temperature 1 H NMR spectroscopy at the temperature range from 25 to 115 °C, and the influence of the nature of anion is discussed accordingly. The results demonstrate that 1 H NMR chemical shifts of alkyl protons of both N4Ac and N4NO3 are almost not changed with the increasing of temperature, due to the absence of hydrogen bond interaction between alkyl protons with anions. Whereas those of + N-H of cation decrease linearly with the temperature increasing, indicating that the hydrogen bond interaction between + N-H and anion weakens gradually. In addition, the strength of hydrogen bond interaction between + N-H and NO3- is stronger than that between + N-H and Ac- , suggesting that anions have a significant influence on microstructure due to the acidity of a Brønsted acid. Consequently, the proton transfer from cation to anion is much easier in N4Ac compared to N4NO3 . Further analyses of 1 H NMR chemical shifts of + N-H in N4Ac at the temperature range from 100 to 115 °C suggest that the splitting of + N-H peak may be attributed to obvious evidence of the existence of the proton transfer from + N-H to Ac- , which leads to dissociate the contact ion-pair in N4Ac to form the neutral ion-pair 'molecule'. The results will help us to extensively understand the behavior of proton transfer and offer us some valuable information for the design of PILs. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  5. Active chemisorption sites in functionalized ionic liquids for carbon capture.

    Science.gov (United States)

    Cui, Guokai; Wang, Jianji; Zhang, Suojiang

    2016-07-25

    Development of novel technologies for the efficient and reversible capture of CO2 is highly desired. In the last decade, CO2 capture using ionic liquids has attracted intensive attention from both academia and industry, and has been recognized as a very promising technology. Recently, a new approach has been developed for highly efficient capture of CO2 by site-containing ionic liquids through chemical interaction. This perspective review focuses on the recent advances in the chemical absorption of CO2 using site-containing ionic liquids, such as amino-based ionic liquids, azolate ionic liquids, phenolate ionic liquids, dual-functionalized ionic liquids, pyridine-containing ionic liquids and so on. Other site-containing liquid absorbents such as amine-based solutions, switchable solvents, and functionalized ionic liquid-amine blends are also investigated. Strategies have been discussed for how to activate the existent reactive sites and develop novel reactive sites by physical and chemical methods to enhance CO2 absorption capacity and reduce absorption enthalpy. The carbon capture mechanisms of these site-containing liquid absorbents are also presented. Particular attention has been paid to the latest progress in CO2 capture in multiple-site interactions by amino-free anion-functionalized ionic liquids. In the last section, future directions and prospects for carbon capture by site-containing ionic liquids are outlined.

  6. Liquid-Liquid Extraction in Systems Containing Butanol and Ionic Liquids – A Review

    Directory of Open Access Journals (Sweden)

    Kubiczek Artur

    2017-03-01

    Full Text Available Room-temperature ionic liquids (RTILs are a moderately new class of liquid substances that are characterized by a great variety of possible anion-cation combinations giving each of them different properties. For this reason, they have been termed as designer solvents and, as such, they are particularly promising for liquid-liquid extraction, which has been quite intensely studied over the last decade. This paper concentrates on the recent liquid-liquid extraction studies involving ionic liquids, yet focusing strictly on the separation of n-butanol from model aqueous solutions. Such research is undertaken mainly with the intention of facilitating biological butanol production, which is usually carried out through the ABE fermentation process. So far, various sorts of RTILs have been tested for this purpose while mostly ternary liquid-liquid systems have been investigated. The industrial design of liquid-liquid extraction requires prior knowledge of the state of thermodynamic equilibrium and its relation to the process parameters. Such knowledge can be obtained by performing a series of extraction experiments and employing a certain mathematical model to approximate the equilibrium. There are at least a few models available but this paper concentrates primarily on the NRTL equation, which has proven to be one of the most accurate tools for correlating experimental equilibrium data. Thus, all the presented studies have been selected based on the accepted modeling method. The reader is also shown how the NRTL equation can be used to model liquid-liquid systems containing more than three components as it has been the authors’ recent area of expertise.

  7. Characterization of PVdF(HFP) gel electrolytes based on 1-(2-Hydroxyethyl)-3-methyl imidazolium ionic liquids.

    Science.gov (United States)

    Yeon, Sun-Hwa; Kim, Ki-Sub; Choi, Sukjeong; Cha, Jong-Ho; Lee, Huen

    2005-09-29

    Poly(vinylidenefluoride)-hexafluoropropylene (PVdF(HFP))-ionic liquid gel electrolytes were prepared using ionic liquids based on 1-(2-hydroxyethyl)-3-methyl imidazolium tetrafluoroborate and 1-(2-hydroxyethyl)-3-methyl imidazolium hexafluorophosphate. A conventional metathesis reaction was used to prepare these ionic liquids, which have high purity and exhibit a liquid state at room temperature. The prepared polymer-ionic liquid gel proved to be a free-standing and rubbery film in which the degree of transparency differed according to the ratio and type of ionic liquid used. TGA and FTIR analyses confirmed that the solvent, N,N-Dimethylacetamide (DMAC), used for mixing PVdF(HFP) polymer with ionic liquid was almost totally removed during the gelling and drying processes. SEM photographs were taken of the surface structure of the PVdF(HFP)-ionic liquid gel in order to evaluate the morphology of the film's surface according to the mixing ratio and the nature of the ionic liquid. The thermal behaviors of PVdF(HFP)-ionic liquid gels were observed to be similar to those of neat ionic liquids through DSC analysis, and the compatibility between the polymer and ionic liquid was investigated by XRD analysis. The ionic conductivities of all the gels were 10(-3)-10(-5) S cm(-1) in a temperature range of 20-70 degrees C.

  8. Aerobic Oxidation of 5-(Hydroxymethyl)furfural in Ionic Liquids with Solid Ruthenium Hydroxide Catalysts

    DEFF Research Database (Denmark)

    Ståhlberg, Tim Johannes Bjarki; Eyjolfsdottir, Ester; Gorbanev, Yury

    2012-01-01

    The aerobic oxidation of 5-(hydroxymethyl)furfural was investigated over solid ruthenium hydroxide catalysts in ionic liquids at elevated temperatures and pressures. Several different catalyst supports were tested in combination with various ionic liquids. The best result was obtained in [EMIm...

  9. SISGR: Physical Chemistry of Reaction Dynamics in Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Blank, David [Univ. of Minnesota, Minneapolis, MN (United States)

    2017-10-30

    Room temperature ionic liquids (RTILs) are liquids made up of atomic and molecular ions. This is in contrast with more common liquids, such as water, that are made up of neutral molecules. The additional charges on the atoms and molecules can alter the properties of these liquids, for example they tend to have a very high vapor pressure and the ability to shield charge in electronic devices. For these and other reasons RTILs have recently been deployed in a number of applications that involve production of free electrons in the liquid, such as batteries, capacitors, nuclear power plants, and solar cells. Electrons tend to be very reactive, and understanding their behaviour in these liquids is important for the future design of ionic liquids to be employed in these environments. This study investigated the behavior of electrons generated in RTILs by pulses of ultraviolet light, including how long they survive, and how reactive they are with the both the surrounding liquid and impurities in the liquid. The ionic liquid studied was one of the most commonly used, called N-alkyl-N-methyl-pyrrolidinium bistriflimide. What the study revealed was that the majority of the electrons initially created, about 96%, had a very short lifetime of less than one picosecond (10-12 second) due to a process called geminate recombination. The study also demonstrated that the electrons are very reactive at the moment they are detached from the molecules in the liquid by light, but that they relax very quickly and lose almost all of their reactivity in much less than one picosecond. The short lifetime and rapid loss of reactivity both serve as important mechanisms that protect the liquid from radiolytic damage.

  10. Room temperature electrodeposition of actinides from ionic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Hatchett, David W.; Czerwinski, Kenneth R.; Droessler, Janelle; Kinyanjui, John

    2017-04-25

    Uranic and transuranic metals and metal oxides are first dissolved in ozone compositions. The resulting solution in ozone can be further dissolved in ionic liquids to form a second solution. The metals in the second solution are then electrochemically deposited from the second solutions as room temperature ionic liquid (RTIL), tri-methyl-n-butyl ammonium n-bis(trifluoromethansulfonylimide) [Me.sub.3N.sup.nBu][TFSI] providing an alternative non-aqueous system for the extraction and reclamation of actinides from reprocessed fuel materials. Deposition of U metal is achieved using TFSI complexes of U(III) and U(IV) containing the anion common to the RTIL. TFSI complexes of uranium were produced to ensure solubility of the species in the ionic liquid. The methods provide a first measure of the thermodynamic properties of U metal deposition using Uranium complexes with different oxidation states from RTIL solution at room temperature.

  11. Interactions in ion pairs of protic ionic liquids: Comparison with aprotic ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Tsuzuki, Seiji, E-mail: s.tsuzuki@aist.go.jp [Research Initiative of Computational Sciences (RICS), Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Shinoda, Wataru [Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Miran, Md. Shah; Kinoshita, Hiroshi; Yasuda, Tomohiro; Watanabe, Masayoshi [Department of Chemistry and Biotechnology, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501 (Japan)

    2013-11-07

    The stabilization energies for the formation (E{sub form}) of 11 ion pairs of protic and aprotic ionic liquids were studied by MP2/6-311G{sup **} level ab initio calculations to elucidate the difference between the interactions of ions in protic ionic liquids and those in aprotic ionic liquids. The interactions in the ion pairs of protic ionic liquids (diethylmethylammonium [dema] and dimethylpropylammonium [dmpa] based ionic liquids) are stronger than those of aprotic ionic liquids (ethyltrimethylammonium [etma] based ionic liquids). The E{sub form} for the [dema][CF{sub 3}SO{sub 3}] and [dmpa][CF{sub 3}SO{sub 3}] complexes (−95.6 and −96.4 kcal/mol, respectively) are significantly larger (more negative) than that for the [etma][CF{sub 3}SO{sub 3}] complex (−81.0 kcal/mol). The same trend was observed for the calculations of ion pairs of the three cations with the Cl{sup −}, BF{sub 4}{sup −}, TFSA{sup −} anions. The anion has contact with the N–H bond of the dema{sup +} or dmpa{sup +} cations in the most stable geometries of the dema{sup +} and dmpa{sup +} complexes. The optimized geometries, in which the anions locate on the counter side of the cations, are 11.0–18.0 kcal/mol less stable, which shows that the interactions in the ions pairs of protic ionic liquids have strong directionality. The E{sub form} for the less stable geometries for the dema{sup +} and dmpa{sup +} complexes are close to those for the most stable etma{sup +} complexes. The electrostatic interaction, which is the major source of the attraction in the ion pairs, is responsible for the directionality of the interactions and determining the magnitude of the interaction energy. Molecular dynamic simulations of the [dema][TFSA] and [dmpa][TFSA] ionic liquids show that the N–H bonds of the cations have contact with the negatively charged (oxygen and nitrogen) atoms of TFSA{sup −} anion, while the strong directionality of the interactions was not suggested from the simulation

  12. A DFT investigation on interactions between lignin and ionic liquids

    Science.gov (United States)

    Wang, Ju; Shi, Xiaoqin; Du, Xihua; Cao, Weiliang

    2017-08-01

    The interactions of the lignin model, the lignin oligomer with degree of polymerization n = 2, with 1-butyl-3-methylimidazolium chloride ionic liquid were investigated through DFT calculations in detail. Computational results revealed that lignin dissolution in ionic liquids should be a result of the joint interactions of lignin with anion and cation of ionic liquid, and the formation of ion pair weakens the interactions between lignin and ionic liquid components. Unlike the dominant H-bonds within the lignin-anion interactions, the lignin-cation interactions involve a combination of hydrogen bond and π-stacking. These results would provide mechanistic insights and suggestions for lignocellulosic dissolution in ionic liquids.

  13. A Review of Ionic Liquid Lubricants

    Directory of Open Access Journals (Sweden)

    Anthony E. Somers

    2013-01-01

    Full Text Available Due to ever increasing demands on lubricants, such as increased service intervals, reduced volumes and reduced emissions, there is a need to develop new lubricants and improved wear additives. Ionic liquids (ILs are room temperature molten salts that have recently been shown to offer many advantages in this area. The application of ILs as lubricants in a diverse range of systems has found that these materials can show remarkable protection against wear and significantly reduce friction in the neat state. Recently, some researchers have shown that a small family of ILs can also be incorporated into non-polar base oils, replacing traditional anti-wear additives, with excellent performance of the neat IL being maintained. ILs consist of large asymmetrical ions that may readily adsorb onto a metal surface and produce a thin, protective film under boundary lubrication conditions. Under extreme pressure conditions, certain IL compounds can also react to form a protective tribofilm, in particular when fluorine, phosphorus or boron atoms are present in the constituent ions.

  14. About the Purification Route of Ionic Liquid Precursors

    Directory of Open Access Journals (Sweden)

    Massimo De Francesco

    2017-03-01

    Full Text Available In this work a purification route of precursors for ionic liquids tailored to electrochemical energy storage systems is reported and described. The study was carried out on the N-butyl-N-methylpyrrolidinium bromide (PYR14Br precursor, which represents the intermediate product of the synthesis process of the N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonylimide (PYR14TFSI hydrophobic ionic liquid. The target is to develop an easy and cost-effective approach for efficiently purifying several kinds of ionic liquid precursors and determining their purity content. The PYR14Br precursor was synthesized through an eco-friendly preparation procedure, which requires water as the only processing solvent, and purified through sorbent materials, such as activated charcoal and alumina. The effect of the treatment/nature/content of sorbents and processing temperature/time was investigated. The impurity content was detected by UV-VIS spectrophotometry measurements. Additionally, a correlation between the measured absorbance and the content of impurities within the precursor was obtained. The purity level of the precursor was seen to play a key role in the electrochemical performance of the ionic liquids.

  15. Synthetic Organic Electrochemistry in Ionic Liquids: The Viscosity Question

    Directory of Open Access Journals (Sweden)

    Scott T. Handy

    2011-07-01

    Full Text Available Ionic liquids are obvious candidates for use in electrochemical applications due to their ionic character. Nevertheless, relatively little has been done to explore their application in electrosynthesis. We have studied the Shono oxidation of arylamines and carbamates using ionic liquids as recyclable solvents and have noted that the viscosity of the medium is a major problem, although with the addition of sufficient co-solvent, good results and excellent recovery and recycling of the ionic liquid can be achieved.

  16. A strategy of utilizing Zn(II) as metallic pivot in room temperature ionic liquid to prepare molecularly imprinted polymers for compound with intramolecular hydrogen bonds.

    Science.gov (United States)

    Sun, Ya Kun; Jia, Man; Yang, Jian; Huang, Yan-Ping; Liu, Zhao-Sheng; Aisa, Haji Akber

    2018-01-01

    A method of preparing molecularly imprinted polymers (MIPs) with Zn(II) as a metallic pivot was adopted to solve the problem of imprinting compound with intramolecular hydrogen bonds by forming stronger coordination binding interaction among the template-functional monomer-Zn2+ complex. A ternary porogenic system including dimethyl sulfoxide, dimethylformamide, and room temperature ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate was employed to fabricate imprinted monolith with high porosity and good flow-through properties, in which chicoric acid (CA), zinc acetate, 4-vinylpyridine (4-VP), and ethylene glycol dimethacrylate (EDMA) was the template, metallic ion, functional monomer, as well as crosslinker, respectively. The influence of polymerization factors including the 4-VP-CA ratio, monomer-crosslinker ratio, template-Zn2+ ratio on imprinting factors was systematically investigated. When the ratio of 4-VP to CA was 24:1, the greatest IF value (24.81) was achieved on the CA-MIP prepared with zinc acetate. In addition, off-line SPE with the optimal MIPs monolith led to high purity of CA (98.0% ± 0.5%) from extraction of Cichorium intybus L. roots with the recovery of 77.5% ± 2.5% (n = 6). As a conclusion, the strategy of introducing metal ions as metal pivot to prepare MIPs was a powerful method for the MIPs synthesis to the template molecules with intramolecular hydrogen bonds.

  17. [Advances of poly (ionic liquid) materials in separation science].

    Science.gov (United States)

    Liu, Cuicui; Guo, Ting; Su, Rina; Gu, Yuchen; Deng, Qiliang

    2015-11-01

    Ionic liquids, as novel ionization reagents, possess beneficial characteristics including good solubility, conductivity, thermal stability, biocompatibility, low volatility and non-flammability. Ionic liquids are attracting a mass of attention of analytical chemists. Poly (ionic liquid) materials have common performances of ionic liquids and polymers, and have been successfully applied in separation science area. In this paper, we discuss the interaction mechanisms between the poly(ionic liquid) materials and analytes including hydrophobic/hydrophilic interactions, hydrogen bond, ion exchange, π-π stacking and electrostatic interactions, and summarize the application advances of the poly(ionic liquid) materials in solid phase extraction, chromatographic separation and capillary electrophoresis. At last, we describe the future prospect of poly(ionic liquid) materials.

  18. Nontoxic Ionic Liquid Fuels for Exploration Applications

    Science.gov (United States)

    Coil, Millicent

    2015-01-01

    The toxicity of propellants used in conventional propulsion systems increases not only safety risks to personnel but also costs, due to special handling required during the entire lifetime of the propellants. Orbital Technologies Corporation (ORBITEC) has developed and tested novel nontoxic ionic liquid fuels for propulsion applications. In Phase I of the project, the company demonstrated the feasibility of several ionic liquid formulations that equaled the performance of conventional rocket propellant monomethylhydrazine (MMH) and also provided low volatility and low toxicity. In Phase II, ORBITEC refined the formulations, conducted material property tests, and investigated combustion behavior in droplet and microreactor experiments. The company also explored the effect of injector design on performance and demonstrated the fuels in a small-scale thruster. The ultimate goal is to replace propellants such as MMH with fuels that are simultaneously high-performance and nontoxic. The fuels will have uses in NASA's propulsion applications and also in a range of military and commercial functions.

  19. Supported ionic liquids fundamentals and applications

    CERN Document Server

    Fehrmann, Rasmus; Haumann, Marco

    2013-01-01

    This unique book gives a timely overview about the fundamentals and applications of supported ionic liquids in modern organic synthesis. It introduces the concept and synthesis of SILP materials and presents important applications in the field of catalysis (e.g. hydroformylation, hydrogenation, coupling reactions, fine chemical synthesis) as well as energy technology and gas separation. Written by pioneers in the field, this book is an invaluable reference book for organic chemists in academia or industry.

  20. Selective extraction of copper, mercury, silver and palladium ionsfrom water using hydrophobic ionic liquids.

    Energy Technology Data Exchange (ETDEWEB)

    Papaiconomou, Nicolas; Lee, Jong-Min; Salminen, Justin; VonStosch, Moritz; Prausnitz, John M.

    2007-06-25

    Extraction of dilute metal ions from water was performed near room temperature with a variety of ionic liquids. Distribution coefficients are reported for fourteen metal ions extracted with ionic liquids containing cations 1-octyl-4-methylpyridinium [4MOPYR]{sup +}, 1-methyl-1-octylpyrrolidinium [MOPYRRO]{sup +} or 1-methyl-1-octylpiperidinium [MOPIP]{sup +}, and anions tetrafluoroborate [BF{sub 4}]{sup +}, trifluoromethyl sulfonate [TfO]{sup +} or nonafluorobutyl sulfonate [NfO]{sup +}. Ionic liquids containing octylpyridinium cations are very good for extracting mercury ions. However, other metal ions were not significantly extracted by any of these ionic liquids. Extractions were also performed with four new task-specific ionic liquids. Such liquids containing a disulfide functional group are efficient and selective for mercury and copper, whereas those containing a nitrile functional group are efficient and selective for silver and palladium.

  1. Two Coexisting Liquid Phases in Switchable Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Juan; Lao, David; Sui, Xiao; Zhou, Yufan; Nune, Satish K.; Ma, Xiang; Troy, Tyler; Ahmed, Musahid; Zhu, Zihua; Heldebrant, David J.; Yu, Xiao-Ying

    2017-08-30

    In situ time-of-flight secondary ion mass spectrometry (ToF-SIMS) coupled with a vacuum compatible microfluidic reactor, System for Analysis at Liquid Vacuum Interface (SALVI), has enabled the first spatial mapping of the switchable ionic liquids (SWILs) derived from 1,8-diazabicycloundec-7-ene (DBU) and 1-hexanol. As predicted by molecular dynamic simulations, our molecular imaging results confirmed a dynamic heterogeneous molecular structure with ionic regions (high CO2 concentration) coexisting with non-ionic regions (no CO2) where stoichiometry would indicate otherwise. Chemical speciation was also found to be more complex than initially thought, with spectral principal component analysis identifying dimers that ultimately highlight a highly complex molecular structure unique to SWILs. The spatial chemical mapping enabled by ToF-SIMS and SALVI advances the understanding of how the heterogeneous molecular structure impacts the dynamic physical and thermodynamic properties or SWILs.

  2. The Heck Reaction in Ionic Liquids: Progress and Challenges

    Directory of Open Access Journals (Sweden)

    Fabio Bellina

    2010-03-01

    Full Text Available As the interest for environmental increases and environmental laws become more stringent, the need to replace existing processes with new more sustainable technologies becomes a primary objective. The use of ionic liquids to replace organic solvents in metal catalyzed reactions has recently gained much attention and great progress has been accomplished in this area in the last years. This paper reviews the recent developments in the application of ionic liquids and related systems (supported ionic liquids, ionic polymers, and so on in the Heck reaction. Merits and achievements of ionic liquids were analyzed and discussed considering the possibility of increasing the effectiveness of industrial processes.

  3. Thermophysical properties of pure and water-saturated tetradecyltrihexylphosphonium-based ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Neves, Catarina M.S.S.; Carvalho, Pedro J.; Freire, Mara G. [Departamento de Quimica, CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Coutinho, Joao A.P., E-mail: jcoutinho@ua.p [Departamento de Quimica, CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal)

    2011-06-15

    Research highlights: {yields} Density and viscosity data of seven pure phosphonium ionic liquids are reported. {yields} Water content of saturated phosphonium ionic liquids is presented. {yields} Density and viscosity data of water-saturated ionic liquids are reported. {yields} Density data is only marginally affected by the presence of water. {yields} The presence of water has a large impact in viscosities. - Abstract: In this work, the solubility of water in several tetradecyltrihexylphosphonium-based ionic liquids at 298.15 K, and densities and viscosities of both pure and water-saturated ionic liquids in a broad temperature range were measured. The selected ionic liquids comprise the common tetradecyltrihexylphosphonium cation combined with the following anions: bromide, chloride, bis(trifluoromethylsulfonyl)imide, decanoate, methanesulfonate, dicyanamide and bis(2,4,4-trimethylpentyl)phosphinate. The isobaric thermal expansion coefficients for pure and water-saturated ionic liquids were determined based on the density dependence with temperature. Taking into account that the excess molar volumes of the current hydrophobic water-saturated ionic liquids are negligible, the solubility of water was additionally estimated from the gathered density data and compared with the experimental solubilities obtained. Moreover, the experimental densities were compared with those predicted by the Gardas and Coutinho model while viscosity data were correlated using the Vogel-Tammann-Fulcher method.

  4. Thermo-responsive poly(ionic liquid) hydrogel microfluidic valves

    OpenAIRE

    Tudor, Alexandru; Saez, Janire; Florea, Larisa; Benito-Lopez, Fernando; Diamond, Dermot

    2016-01-01

    Several phosphonium ionic liquid monomers have been shown to possess a lower critical solution temperature [1][2]. This property was kept when the monomers were used to synthesize both linear and crosslinked polymers, thus making them suitable materials for the synthesis of stimuli-responsive hydrogels [2]. Herein, we present the synthesis of a thermo-responsive tributylhexyl phosphonium 3-sulfopropyl acrylate (PSPA) crosslinked PIL, followed by its inclusion in a microfluidic device to be us...

  5. Room-temperature ionic liquids as electrolytes in electroanalytical determination of traces of 2-furaldehyde from oil and related wastewaters from refining processes.

    Science.gov (United States)

    Shamsipur, Mojtaba; Beigi, Ali Akbar Miran; Teymouri, Mohammad; Ghorbani, Yousefali; Irandoust, Mohsen; Mehdizadeh, Ali

    2010-04-15

    Three different ionic liquids, 1-ethyl-3-methylimidazolium tetrafluoroborate, [EMIM][BF(4)]; 1-butyl-3-methylimidazolium trifluoromethanesulfonate, [BMIM][OTf]; and 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide [bmpyrr][NTf(2)] were studied as electrolytes in the electroanalytical quantification of 2-furaldehyde using square wave and differential pulse voltammetries. On applying a cathodic scan, a well-defined 2-electron wave was observed corresponding to the reduction of 2-furaldehyde to furfuryl alcohol. The electrochemical stability of the ionic liquids as electrolytes for analytical aspects and electrokinetic studies was investigated using a glassy carbon electrode (GCE). The measurements were carried out in a designed double-wall three-electrode cell, using two platinum wires as the quasi-reference and counter electrodes. Differential pulse voltammetry was found to be the most sensitive method at GCE. The detection limits of 1.4, 19.0 and 2.5 microg g(-1) were obtained for the determination of 2-furaldehyde in [EMIM][BF(4)], [BMIM][OTf] and [BMPyrr][NTf(2)], respectively. At a concentration of 50 microg g(-1), the maximum relative standard deviation (n=3) was 4.9%. The effect of water content of the ionic liquids on their potential windows and waveforms was also investigated. The proposed method was successfully applied to the determination of 2-furaldehyde in real samples, especially in oil matrices. (c) 2009 Elsevier B.V. All rights reserved.

  6. Electrochemical characterisations and ageing of ionic liquid/γ-butyrolactone mixtures as electrolytes for supercapacitor applications over a wide temperature range

    Science.gov (United States)

    Dagousset, Laure; Pognon, Grégory; Nguyen, Giao T. M.; Vidal, Frédéric; Jus, Sébastien; Aubert, Pierre-Henri

    2017-08-01

    Electrochemical properties in mesoporous media of three different ionic liquids (1-propyl-1-methylpyrrolidinium-bis(fluorosulfonyl)imide - Pyr13FSI, 1-butyl-1-methylpyrrolidinium-bis(trifluoromethanesulfonyl)imide - Pyr14TFSI and 1-ethyl-3-methylimidazolium-bis(trifluoromethanesulfonyl)imide - EMITFSI) are investigated from -50 °C to 100 °C and compared with binary mixtures with γ-butyrolactone (GBL). Buckypaper composed of Single-Wall Carbon Nanotubes (SWCNTs) are used to prepare and study coin-cell supercapacitors. Supercapacitor using Pyr13FSI/GBL present a rapid loss of capacitance after only a thousand cycles at 100 °C. On the contrary, EMITFSI/GBL and Pyr14TFSI/GBL prove to be very promising at high temperature (the capacitance loss after 10,000 cycles is 9% and 10%). More drastic ageing tests such as floating are also carried out for these two mixtures at 100 °C and -50 °C. 23% and 15% capacitance losses have been recorded after 500 h of floating at 100 °C for EMITFSI/GBL and Pyr14TFSI/GBL. The capacitance of supercapacitors based on Pyr14TFSI/GBL dropped by 20% after 200 h of floating at -50 °C rather than EMITFSI/GBL show a remarkable stability during floating at -50 °C, with 6.6% capacitance loss after 500 h (3 V at -50 °C). These results show that the mixture EMITFSI/GBL works properly all along the broad range of temperature [-50 °C to +100 °C] and thus proved that our approach is very promising for the development of high performances supercapacitors specifically adapted for extreme environment.

  7. Synthesis and development of ordered, phase-separated, room-temperature ionic liquid-based AB and ABC block copolymers for gas separation applications

    Science.gov (United States)

    Wiesenauer, Erin F.

    CO2 capture process development is an economically and environmentally important challenge, as concerns over greenhouse gas emissions continue to receive worldwide attention. Many applications require the separation of CO 2 from other light gases such as N2, CH4, and H2 and a number of technologies have been developed to perform such separations. While current membrane technology offers an economical, easy to operate and scale-up solution, polymeric membranes cannot withstand high temperatures and aggressive chemical environments, and they often exhibit an unfavorable tradeoff between permeability and selectivity. Room-temperature ionic-liquids (RTILs) are very attractive as next-generation CO2-selective separation media and their development into polymerized membranes combat these challenges. Furthermore, polymers that can self-assemble into nanostructured, phase-separated morphologies (e.g., block copolymers, BCPs) have a direct effect on gas transport as materials morphology can influence molecular diffusion and membrane transport performance. In this thesis, nanophase-separated, RTIL-based AB and ABC di- and tri-BCPs were prepared via the sequential, living ring-opening metathesis polymerization (ROMP) of an IL-based monomer and one or more mutually immiscible co-monomers. This novel type of ion-containing BCP system forms various ordered nanostructures in the melt state via primary and secondary structure control. Monomer design and control of block composition, sequence, and overall polymer lengths were found to directly affect the ordered polymer assembly. Supported, composite membranes of these new BCPs were successfully fabricated, and the effect of BCP composition and nanostructure on CO2/light gas transport properties was studied. These nanostructured IL-based BCPs represent innovative polymer architectures and show great potential CO2/light gas membrane separation applications.

  8. Acrylate Functionalized Tetraalkylammonium Salts with Ionic Liquid Properties

    Directory of Open Access Journals (Sweden)

    Silvia Janietz

    2012-05-01

    Full Text Available Acrylate functionalized ionic liquids based on tetraalkylammonium salts with terminal acrylates- and methylacrylates were synthesized. Melting points and ionic conductivity of twenty compounds in six groups were determined. Within one group the effect of three different counterions was investigated and discussed. The groups differ in cationic structure elements because of their functional groups such as acrylate and methacrylate, alkyl residues at the nitrogen and number of quaternary ammonium atoms within the organic cation. The effect of these cationic structure elements has been examined concerning the compiled parameters with a view to qualifying them as components for solid state electrolytes. The newly synthesized ionic liquids were characterized by NMR and FTIR analysis. The exchange of halide ions like bromide as counter ions to weakly coordinating [PF6], [OTf] or [TFSI] reduces the melting points significantly and leads to an ion conductivity of about 10−4 S/cm at room temperature. In the case of the dicationic ionic liquid, an ion conductivity of about 10−3 S/cm was observed.

  9. Ionic liquid based multifunctional double network gel

    Science.gov (United States)

    Ahmed, Kumkum; Higashihara, Tomoya; Arafune, Hiroyuki; Kamijo, Toshio; Morinaga, Takashi; Sato, Takaya; Furukawa, Hidemitsu

    2015-04-01

    Gels are a promising class of soft and wet materials with diverse application in tissue engineering and bio-medical purpose. In order to accelerate the development of gels, it is required to synthesize multi-functional gels of high mechanical strength, ultra low surface friction and suitable elastic modulus with a variety of methods and new materials. Among many types of gel ionic gel made from ionic liquids (ILs) could be used for diverse applications in electrochemical devices and in the field of tribology. IL, a promising materials for lubrication, is a salt with a melting point lower than 100 °C. As a lubricant, ILs are characterized by an extremely low vapor pressure, high thermal stability and high ion conductivity. In this work a novel approach of making double network DN ionic gel using IL has been made utilizing photo polymerization process. A hydrophobic monomer Methyl methacrylate (MMA) has been used as a first network and a hydrophobic IL monomer, N,N-diethyl-N-(2-mthacryloylethyl)-N-methylammonium bistrifluoromethylsulfonyl)imide (DEMM-TFSI) has been used as a second network using photo initiator benzophenon and crosslinker triethylene glycol dimethacrylate (TEGDMA). The resulting DN ionic gel shows transparency, flexibility, high thermal stability, good mechanical toughness and low friction coefficient value which can be a potential candidate as a gel slider in different mechanical devices and can open a new area in the field of gel tribology.

  10. Conductivity-Relaxation Relations in Nanocomposite Polymer Electrolytes Containing Ionic Liquid.

    Science.gov (United States)

    Shojaatalhosseini, Mansoureh; Elamin, Khalid; Swenson, Jan

    2017-10-19

    In this study, we have used nanocomposite polymer electrolytes, consisting of poly(ethylene oxide) (PEO), δ-Al2O3 nanoparticles, and lithium bis(trifluoromethanesolfonyl)imide (LiTFSI) salt (with 4 wt % δ-Al2O3 and PEO:Li ratios of 16:1 and 8:1), and added different amounts of the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesolfonyl)imide (BMITFSI). The aim was to elucidate whether the ionic liquid is able to dissociate the Li-ions from the ether oxygens and thereby decouple the ionic conductivity from the segmental polymer dynamics. The results from DSC and dielectric spectroscopy show that the ionic liquid speeds up both the segmental polymer dynamics and the motion of the Li(+) ions. However, a close comparison between the structural (α) relaxation process, given by the segmental polymer dynamics, and the ionic conductivity shows that the motion of the Li(+) ions decouples from the segmental polymer dynamics at higher concentrations of the ionic liquid (≥20 wt %) and instead becomes more related to the viscosity of the ionic liquid. This decoupling increases with decreasing temperature. In addition to the structural α-relaxation, two more local relaxation processes, denoted β and γ, are observed. The β-relaxation becomes slightly faster at the highest concentration of the ionic liquid (at least for the lower salt concentration), whereas the γ-relaxation is unaffected by the ionic liquid, over the whole concentration range 0-40 wt %.

  11. Detection of Ionic liquid using terahertz time-domain spectroscopy

    Science.gov (United States)

    Wang, Cuicui; Zhao, Xiaojing; Liu, Shangjian; Zuo, Jian; Zhang, Cunlin

    2018-01-01

    Terahertz (THz, THz+1012Hz) spectroscopy is a far-infrared analytical technology with spectral bands locating between microware and infrared ranges. Being of excellent transmission, non-destruction and high discrimination, this technology has been applied in various fields such as physics, chemistry, nondestructive detection, communication, biomedicine public security. Terahertz spectrum is corresponding with vibration and rotation of liquid molecules, which is suitable to identify and study the liquid molecular dynamics. It is as a powerful spectral detection technology, terahertz time-domain spectroscopy is widely used in solution detection. can enable us to extract the material parameters or dielectric spectrum that show material micro-structure and dynamics by measuring amplitude and phase from coherent terahertz pulses. Ionic liquid exists in most biological tissues, and it is very important for life. It has recently been suggested that near-fired terahertz ionic contrast microscopy can be employed to image subtle changes in ionic concentrations arising from neuronal activity. In this paper, we detected Ionic liquid with different concentrations at room temperature by THz-TDS technique in the range of 0.2-1.5 THz. The liquid cell with a thickness of 0.2mm is made of quartz. The absorption coefficient, refractive index and dielectric function of solutions can be extracted based on THz-TDS. We use an expanded model for fitting the dielectric function based on a combination of a Debye relation for the anions and cations. We find A linear increase of the real and imaginary part of the dielectric function compared with pure water with increasing ion concentrations. A good agreement between the model and the experimental results is obtained. By means of dielectric relaxation process, it was found that the characteristic time of molecular movement and the information related to the liquid molecular structure and movement was obtained.

  12. Theoretical Study of Renewable Ionic Liquids in the Pure State and with Graphene and Carbon Nanotubes.

    Science.gov (United States)

    García, Gregorio; Atilhan, Mert; Aparicio, Santiago

    2015-09-17

    The N-ethyl-N-(furan-2-ylmethyl)ethanaminium dihydrogen phosphate ionic liquid was studied as a model of ionic liquids which can be produced from totally renewable sources. A computational study using both molecular dynamics and density functional theory methods was carried out. The properties, structuring, and intermolecular interactions (hydrogen bonding) of this fluid in the pure state were studied as a function of pressure and temperature. Likewise, the adsorption on graphene and the confinement between graphene sheets was also studied. The solvation of single walled carbon nanotubes in the selected ionic liquid was analyzed together with the behavior of ions confined inside these nanotubes. The reported results show remarkable properties for this fluid, which show that many of the most relevant properties of ionic liquids and their ability to interact with carbon nanosystems may be maintained and even improved using new families of renewable compounds instead of classic types of ionic liquids with worse environmental, toxicological, and economical profiles.

  13. Oxidative desulfurization of fuel oil by pyridinium-based ionic liquids.

    Science.gov (United States)

    Zhao, Dishun; Wang, Yanan; Duan, Erhong

    2009-10-28

    In this work, an N-butyl-pyridinium-based ionic liquid [BPy]BF(4) was prepared. The effect of extraction desulfurization on model oil with thiophene and dibenzothiophene (DBT) was investigated. Ionic liquids and hydrogen peroxide (30%) were tested in extraction-oxidation desulfurization of model oil. The results show that the ionic liquid [BPy]BF(4) has a better desulfurization effect. The best technological conditions are: V(IL)/V(Oil) /V(H(2)O(2)) = 1:1:0.4, temperature 55 degrees C, the time 30 min. The ratio of desulfurization to thiophene and DBT reached 78.5% and 84.3% respectively, which is much higher than extraction desulfurization with simple ionic liquids. Under these conditions, the effect of desulfurization on gasoline was also investigated. The used ionic liquids can be recycled up to four times after regeneration.

  14. Hydrogen-Bond Dynamics in a Protic Ionic Liquid: Evidence of Large-Angle Jumps.

    Science.gov (United States)

    Hunger, Johannes; Sonnleitner, Thomas; Liu, Liyuan; Buchner, Richard; Bonn, Mischa; Bakker, Huib J

    2012-10-18

    We study the molecular rotation of the protic room-temperature ionic liquid ethylammonium nitrate with dielectric relaxation spectroscopy and femtosecond-infrared spectroscopy (fs-IR) of the ammonium N-H vibrations. The results suggest that the rotation of ethylammonium ion takes place via large angular jumps. Such nondiffusive reorientational dynamics is unique to strongly hydrogen-bonded liquids such as water and indicates that the intermolecular interaction is highly directional in this class of ionic liquids.

  15. Tetraalkylphosphonium polyoxometalate ionic liquids: novel, organic-inorganic hybrid materials.

    Science.gov (United States)

    Rickert, Paul G; Antonio, Mark R; Firestone, Millicent A; Kubatko, Karrie-Ann; Szreder, Tomasz; Wishart, James F; Dietz, Mark L

    2007-05-10

    Pairing of a Keggin or Lindqvist polyoxometalate (POM) anion with an appropriate tetraalkylphosphonium cation is shown to yield the first members of a new family of ionic liquids (ILs). Detailed characterization of one of them, an ambient-temperature "liquid POM" comprising the Lindqvist salt of the trihexyl(tetradecyl) phosphonium cation, by voltammetry, viscometry, conductimetry, and thermal analysis indicates that it exhibits conductivity and viscosity comparable to those of the one previously described inorganic-organic POM-IL hybrid but with substantially improved thermal stability.

  16. Tetraalkylphosphonium polyoxometalate ionic liquids : novel, organic-inorganic hybrid materials.

    Energy Technology Data Exchange (ETDEWEB)

    Rickert, P. G.; Antonio, M. P.; Firestone, M. A.; Kubatko, K.-A.; Szreder, T.; Wishart, J. F.; Dietz, M. L.; Chemistry; Univ. of Notre Dame; BNL

    2007-01-01

    Pairing of a Keggin or Lindqvist polyoxometalate (POM) anion with an appropriate tetraalkylphosphonium cation is shown to yield the first members of a new family of ionic liquids (ILs). Detailed characterization of one of them, an ambient-temperature 'liquid POM' comprising the Lindqvist salt of the trihexyl(tetradecyl) phosphonium cation, by voltammetry, viscometry, conductimetry, and thermal analysis indicates that it exhibits conductivity and viscosity comparable to those of the one previously described inorganic-organic POM-IL hybrid but with substantially improved thermal stability.

  17. Ionic liquids, new class of industrial solvents; Les liquides ioniques, nouvelle classe de solvants industriels

    Energy Technology Data Exchange (ETDEWEB)

    Lepetit, V

    2004-02-01

    Ionic liquids are liquid salts at ambient temperature and can solubilize the organo-metallic compounds like enzymes. Their potential applications concern: the petrochemistry, the bio-catalysis and the treatment of nuclear effluents (extraction of actinides). They are neither volatile, nor flammable, they are good electrical conductors, they have high solvent properties and they are not miscible with most of the organic solvents. Their properties (viscosity, density etc..) can be modified by simply changing the cation and proton. (J.S.)

  18. Diglycolamide-functionalized calix[4]arenes showing unusual complexation of actinide ions in room temperature ionic liquids: role of ligand structure, radiolytic stability, emission spectroscopy, and thermodynamic studies.

    Science.gov (United States)

    Mohapatra, Prasanta K; Sengupta, Arijit; Iqbal, Mudassir; Huskens, Jurriaan; Verboom, Willem

    2013-03-04

    Diglycolamide-functionalized calix[4]arenes (C4DGAs) with varying structural modifications were evaluated for actinide complexation from their extraction behavior toward actinide ions such as UO2(2+), Pu(4+), PuO2(2+), and Am(3+) in the room temperature ionic liquid (RTIL) 1-n-octyl-3-methylimidazolium bis(trifluoromethane)sulfonamide (C8mimNTf2). The formation constants were calculated for Am(3+) which showed a significant role of ligand structure, nature of substituents, and spacer length. Although the alkyl substituents on the amidic nitrogen increase the extraction efficiency of americium at lower acidity because of the inductive effect of the alkyl groups, at higher acidity the steric crowding around the ligating site determines the extraction efficiency. All C4DGAs formed 1:1 complexes with Am(3+) while for the analogous Eu(3+) complexes no inner sphere water molecules were detected and the asymmetry of the metal ligand complex differed from one another as proved by time-resolved laser induced fluorescence spectroscopy (TRLIFS). Thermodynamic studies indicated that the extraction process, predominant by the Am(3+)-C4DGA complexation reaction, is exothermic. The unique role of the medium on Am(3+) complexation with the C4DGA molecules with varying spacer length, L-IV and L-V, was noticed for the first time with a reversal in the trend observed in the RTIL compared to that seen in a nonpolar molecular diluent like n-dodecane. Various factors leading to a more preorganized structure were responsible for favorable metal ion complexation. The solvent systems show promise to be employed for nuclear waste remediation, and sustainability options were evaluated from radiolytic stability as well as stripping studies.

  19. Acceleration effect of ionic liquids on polycyclotrimerization of dicyanate esters

    Directory of Open Access Journals (Sweden)

    A. Fainleib

    2016-09-01

    Full Text Available The polycyclotrimerization reaction of dicyanate ester of bisphenol E (DCBE in the presence of varying amounts (from 0.5 to 5 wt% of 1-octyl-3-methylimidazolium tetrafluoroborate ([OMIm][BF4] ionic liquid has been investigated using differential scanning calorimetry (DSC and Fourier transform infrared spectroscopy (FTIR techniques, after a curing stage at 150 °C for 6 h. It is noteworthy that an amount of [OMIm][BF4] as low as 0.5 wt% accelerates dramatically the thermal curing process leading to the formation of a polycyanurate network. The conversion of DCBE increased with increasing [OMIm][BF4] content in the temperature range studied. A reaction mechanism associated with the ionic liquid-catalyzed DCBE polycyclotrimerization is newly proposed via the involvement of a [CN]δ+–[OMIm]δ– complex as a key intermediate.

  20. Reactions of Lignin Model Compounds in Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Holladay, John E.; Binder, Joseph B.; Gray, Michel J.; White, James F.; Zhang, Z. Conrad

    2009-09-15

    Lignin, a readily available form of biomass, awaits novel chemistry for converting it to valuable aromatic chemicals. Recent work has demonstrated that ionic liquids are excellent solvents for processing woody biomass and lignin. Seeking to exploit ionic liquids as media for depolymerization of lignin, we investigated reactions of lignin model compounds in these solvents. Using Brønsted acid catalysts in 1-ethyl-3-methylimidazolium triflate at moderate temperatures, we obtained up to 11.6% yield of the dealkylation product guaiacol from the model compound eugenol and cleaved phenethyl phenyl ether, a model for lignin ethers. Despite these successes, acid catalysis failed in dealkylation of the unsaturated model compound 4-ethylguaiacol and did not produce monomeric products from organosolv lignin, demonstrating that further work is required to understand the complex chemistry of lignin depolymerization.

  1. Ionic liquids for addressing unmet needs in healthcare.

    Science.gov (United States)

    Agatemor, Christian; Ibsen, Kelly N; Tanner, Eden E L; Mitragotri, Samir

    2018-01-01

    Advances in the field of ionic liquids have opened new applications beyond their traditional use as solvents into other fields especially healthcare. The broad chemical space, rich with structurally diverse ions, and coupled with the flexibility to form complementary ion pairs enables task-specific optimization at the molecular level to design ionic liquids for envisioned functions. Consequently, ionic liquids now are tailored as innovative solutions to address many problems in medicine. To date, ionic liquids have been designed to promote dissolution of poorly soluble drugs and disrupt physiological barriers to transport drugs to targeted sites. Also, their antimicrobial activity has been demonstrated and could be exploited to prevent and treat infectious diseases. Metal-containing ionic liquids have also been designed and offer unique features due to incorporation of metals. Here, we review application-driven investigations of ionic liquids in medicine with respect to current status and future potential.

  2. Theoretical study on interactions between lignocellulose components and ionic liquids

    Science.gov (United States)

    Wang, J.; Zhuang, W. C.; Shi, X. Q.; Cao, W. L.

    2017-09-01

    Interactions between lignocellulose and ionic liquids have been studied by designed lignocellulose components models, and their complexes with 1-butyl-3-methylimidazolium chloride. All the structures were optimized by DFT methods and hydrogen bonds within lignocelluloses components, and their complexes with 1-butyl-3-methylimidazolium chloride were investigated by AIM calculations. Our calculated results demonstrate that when dissolved in ionic liquids, the stable intermolecular hydrogen bonds and weak π-stacking interactions between ionic liquids and lignocelluloses components reduce the energy of complex systems, which are advantageous for lignocelluloses components dissolution in ionic liquids. Moreover, there are deformation accrued for both lignocelluloses components and ionic liquids, which may be a prerequisite for lignocelluloses components dissolution in ionic liquids.

  3. Aerobic, catalytic oxidation of alcohols in ionic liquids

    Directory of Open Access Journals (Sweden)

    Souza Roberto F. de

    2006-01-01

    Full Text Available An efficient and simple catalytic system based on RuCl3 dissolved in ionic liquids has been developed for the oxidation of alcohols into aldehydes and ketones under mild conditions. A new fluorinated ionic liquid, 1-n-butyl-3-methylimidazolium pentadecafluorooctanoate, was synthesized and demonstrated better performance that the other ionic liquids employed. Moreover this catalytic system utilizes molecular oxygen as an oxidizing agent, producing water as the only by-product.

  4. Fluorine-functionalized ionic liquids with high oxygen solubility

    OpenAIRE

    Vanhoutte, Gijs; Hojniak, Sandra; Bardé, Fanny; Binnemans, Koen; Fransaer, Jan

    2018-01-01

    Eight fluorine-functionalized ionic liquids were synthesized and the oxygen solubility was compared to commercial ionic liquids without the extra fluorinated chain. The concentration of dissolved oxygen increased with the fluorine content of the alkyl chain, which can be attached either to the cation or the anion. This approach maintains the freedom to design an ionic liquid for a specific application, while at the same time the oxygen solubility is increased.

  5. Synthesis and Physico-Chemical Properties of New Tetraethylammonium-Based Amino Acid Chiral Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Mohd Basyaruddin Abdul Rahman

    2010-04-01

    Full Text Available This paper reports the synthesis of a series of new tetraethylammonium-based amino acid chiral ionic liquids (CILs. Their physico-chemical properties, including melting point, thermal stability, viscosity and ionic conductivity, have been comprehensively studied. The obtained results indicated that the decomposition for these salts proceeds in one step and the temperature of decomposition (Tonset is in the range of 168–210 °C. Several new CILs prepared in this work showed high ionic conductivity compared to the amino acid ionic liquids (AAILs found in the literature.

  6. Electro-tactic ionic liquid droplets

    OpenAIRE

    Francis, Wayne; Wagner, Klaudia; Beirne, Stephen; Officer, David; Wallace, Gordon; Florea, Larisa; Diamond, Dermot

    2015-01-01

    Here we report for the first time electro-guided, self-propelled droplets, which are composed solely of an ionic liquid (IL), namely trihexyl(tetradecyl)phosphonium chloride ([P6,6,6,14][Cl]). These self-propelled droplets travel along an aqueous-air boundary and are guided to specific destinations within the fluidic network through the use of electro-chemically generated Cl- gradients. The direction of movement can be controlled by switching the impressed voltage (9V, ON or OFF) and polarity...

  7. Design of Separation Processes with Ionic Liquids

    DEFF Research Database (Denmark)

    Peng-noo, Worawit; Kulajanpeng, Kusuma; Gani, Rafiqul

    2015-01-01

    A systematic methodology for screening and designing of Ionic Liquid (IL)-based separation processes is proposed and demonstrated using several case studies of both aqueous and non-aqueous systems, for instance, ethanol + water, ethanol + hexane, benzene + hexane, and toluene + methylcyclohexane....... The best four ILs of each mixture are [mmim][dmp], [emim][bti], [emim][etso4] and [hmim][tcb], respectively. All of them were used as entrainers in the extractive distillation. A process simulation of each system was carried out and showed a lower both energy requirement and solvent usage as compared...

  8. Research and Development of Energetic Ionic Liquids

    Science.gov (United States)

    2012-03-01

    certainly achieved • Performance near TNT • Synthesis undertaken seeking IL with higher energy cation, AMT (1-amino-3- methyl -1,2,3 triazolium...Distribution A: Public Release, Distribution unlimited.” AMT-DNT Properties Properties of AMT-DNT improvement over HEAT-DNT 1-amino-3- methyl -1,2,3- triazolium...Navy/AF) – USAF AF-M315E • Propellant uses ionic liquids to yield low vapor toxicity 22 – Sweden/ECAPS LMP-103S • Propellant uses ADN -based formulation

  9. Ionic Liquids in HPLC and CE: A Hope for Future.

    Science.gov (United States)

    Ali, Imran; Suhail, Mohd; Sanagi, Mohd Marsin; Aboul-Enein, Hassan Y

    2017-07-04

    The ionic liquids (ILs) are salts with melting points below 100°C. These are called as ionic fluids, ionic melts, liquid electrolytes, fused salts, liquid salts, ionic glasses, designer solvents, green solvents and solvents of the future. These have a wide range of applications, including medical, pharmaceutical and chemical sciences. Nowadays, their use is increasing greatly in separation science, especially in chromatography and capillary electrophoresis due to their remarkable properties. The present article describes the importance of ILs in high-performance liquid chromatography and capillary electrophoresis. Efforts were also made to highlight the future expectations of ILs.

  10. Lipid extraction from microalgae using a single ionic liquid

    Science.gov (United States)

    Salvo, Roberto Di; Reich, Alton; Dykes, Jr., H. Waite H.; Teixeira, Rodrigo

    2013-05-28

    A one-step process for the lysis of microalgae cell walls and separation of the cellular lipids for use in biofuel production by utilizing a hydrophilic ionic liquid, 1-butyl-3-methylimidazolium. The hydrophilic ionic liquid both lyses the microalgae cell walls and forms two immiscible layers, one of which consists of the lipid contents of the lysed cells. After mixture of the hydrophilic ionic liquid with a suspension of microalgae cells, gravity causes a hydrophobic lipid phase to move to a top phase where it is removed from the mixture and purified. The hydrophilic ionic liquid is recycled to lyse new microalgae suspensions.

  11. Aprotic Heterocyclic Anion Triazolide Ionic Liquids - A New Class of Ionic Liquid Anion Accessed by the Huisgen Cycloaddition Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Robert [National Energy Technology Laboratory; Damodaran, Krishnan [Department of Chemistry, University of Pittsburgh; Luebke, David [National Energy Technology Laboratory; Nulwala, Hunaid [National Energy Technology Laboratory

    2013-04-18

    The triazole core is a highly versatile heterocyclic ring which can be accessed easily with the Cu(I)-catalyzed Huisgen cycloaddition reaction. Herein we present the preparation of ionic liquids that incorporate a 1,2,3-triazolide anion. These ionic liquids were prepared by a facile procedure utilizing a base-labile pivaloylmethyl group at the 1-position, which can act as precursors to 1H- 4-substituted 1,2,3-triazole. These triazoles were then subsequently converted into ionic liquids after deprotonation using an appropriate ionic liquid cation hydroxide. The densities and thermal decompositions of these ionic liquids were measured. These novel ionic liquids have potential applications in gas separations and in metal-free catalysis.

  12. Applications of ionic liquids in biphasic separation: Aqueous biphasic systems and liquid-liquid equilibria.

    Science.gov (United States)

    Shukla, Shashi Kant; Pandey, Shubha; Pandey, Siddharth

    2017-10-10

    Ionic liquids (ILs) have been receiving much attention in many fields of analytical chemistry because of their various interesting properties which distinguish them from volatile organic compounds. They offer both directional and non-directional forces towards a solute molecule and therefore act as excellent solvents for a wide range of polar and non-polar compounds. Because of the presence of various possible interactions, ILs easily undergo biphasic separation with water and other less polar/non-polar organic solvents. Their ability to create biphasic splitting makes them a promising candidate for liquid-liquid separation processes, such as aqueous biphasic systems and liquid-liquid equilibria. Various aspects of ILs in these separation methods are discussed in view of the origin of physical forces responsible for the biphasic interactions, the effect of structural components, temperature, pressure, pH and additives. The specific advantages of using ILs in aqueous biphasic systems and liquid-liquid equilibria in binary and ternary systems are discussed with a view to defining their future role in separation processes by giving major emphasis on developing non-toxic ILs with physical and solution properties tailored to the needs of specific sample preparation techniques. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Homogeneous Liquid–Liquid Extraction of Rare Earths with the Betaine—Betainium Bis(trifluoromethylsulfonyl)imide Ionic Liquid System

    Science.gov (United States)

    Hoogerstraete, Tom Vander; Onghena, Bieke; Binnemans, Koen

    2013-01-01

    Several fundamental extraction parameters such as the kinetics and loading were studied for a new type of metal solvent extraction system with ionic liquids. The binary mixture of the ionic liquid betainium bis(trifluoromethylsulfonyl)imide and water shows thermomorphic behavior with an upper critical solution temperature (UCST), which can be used to avoid the slower mass transfer due to the generally higher viscosity of ionic liquids. A less viscous homogeneous phase and mixing on a molecular scale are obtained when the mixture is heated up above 55 °C. The influence of the temperature, the heating and cooling times, were studied for the extraction of neodymium(III) with betaine. A plausible and equal extraction mechanism is proposed in bis(trifluoromethylsulfonyl)imide, nitrate, and chloride media. After stripping of the metals from the ionic liquid phase, a higher recovery of the ionic liquid was obtained by salting-out of the ionic liquid fraction lost by dissolution in the aqueous phase. The change of the upper critical solution temperature by the addition of HCl or betaine was investigated. In addition, the viscosity was measured below and above the UCST as a function of the temperature. PMID:24169434

  14. Application of a room temperature ionic liquid for nuclear spent fuel reprocessing: speciation of trivalent europium and solvatation effects; Application d'un liquide ionique basse temperature pour les procedes de separation: speciation de l'europium trivalent et effets solvatation

    Energy Technology Data Exchange (ETDEWEB)

    Moutiers, G.; Mekki, S. [CEA Saclay, Dept. de Physico-Chimie, Service de Chimie Physique, 91 - Gif sur Yvette (France); Billard, I. [IN2P3/CNRS, 69 - Villeurbanne (France)

    2007-07-01

    One of the solutions proposed for the optimization of the long term storage and conditioning of spent nuclear fuel is to separate actinide and lanthanide both from each other and from other less radioactive metallic species. The industrial proposed processes, based on liquid liquid extraction steps, involve solvents with non negligible vapour pressure and may generate contaminated liquid wastes that will have to be reprocessed. During the last decade, some room-temperature ionic liquids have been studied and integrated into industrial processes. The interest on this class of solvent came out from their 'green' properties (non volatile, non flammable, recyclable, etc...), but also from the variability of their physico-chemical properties (stability, hydrophobicity, viscosity) as a function of the RTIL chemical composition. Indeed, it has been shown that classical chemical industrial processes could be transferred into those media, even more improved, while a certain number of difficulties arising from using traditional solvent can be avoided. In this respect, it could be promising to investigate the ability to use room temperature ionic liquid into the spent nuclear fuel reprocessing field. The aim of this this study is to test the ability of the specific ionic liquid bumimTf{sub 2}N to allow trivalent europium extraction. The choice of this metal is based on the chemical analogy with trivalent minor actinides Curium and Americium which are contributing the greatest part of the long-lived high level radioactive wastes. Handling these elements needs to be very cautious for the safety and radioprotection aspect. Moreover, europium is a very sensitive luminescent probe to its environment even at the microscopic scale. The report is structured with four parts. In a first chapter, we present the main physico-chemical properties of an imidazolium-based ionic liquid family, and then we choose the ionic liquid bumimTf{sub 2}N for the whole thesis and start with

  15. Electrochemically stable fluorohydrogenate ionic liquids based on quaternary phosphonium cations

    Energy Technology Data Exchange (ETDEWEB)

    Kanematsu, Shunsuke; Matsumoto, Kazuhiko; Hagiwara, Rika [Graduate School of Energy Science, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan)

    2009-06-15

    Fluorohydrogenate ionic liquids of quaternary phosphonium cations, tri-n-butylmethylphosphonium (P{sub 4441}) fluorohydrogenate, tetra-n-butylphosphonium (P{sub 4444}) fluorohydrogenate, and tri-n-butyl-n-octylphosphonium (P{sub 4448}) fluorohydrogenate, have been synthesized by the metatheses of anhydrous hydrogen fluoride and the corresponding phosphonium chloride precursors. All the obtained salts have melting points below room-temperature with a vacuum-stable composition of P{sub 444m}(FH){sub 2.3}F (m = 1, 4, and 8) and were characterized by density, conductivity, and viscosity measurements. Linear sweep voltammetry with a glassy carbon working electrode shows that the P{sub 444m}(FH){sub 2.3}Fs have wide electrochemical windows exceeding 5.2 V. In particular, P{sub 4441}(FH){sub 2.3}F has an electrochemical window of 6.0 V, which is the widest among fluorohydrogenate ionic liquids reported to date. The thermal stability of these ionic liquids is also improved compared to the salts of N-heterocyclic ammonium cations. (author)

  16. Choline-derivative-based ionic liquids.

    Science.gov (United States)

    Pernak, Juliusz; Syguda, Anna; Mirska, Ilona; Pernak, Anna; Nawrot, Jan; Pradzyńska, Aleksandra; Griffin, Scott T; Rogers, Robin D

    2007-01-01

    A total of sixty-three choline derivative-based ionic liquids in the forms of chlorides, acesulfamates, and bis(trifluoromethylsulfonyl)imides have been prepared and their physical properties (density, viscosity, solubility, and thermal stability) have been determined. Thirteen of these salts are known chlorides: precursors to the 26 water-soluble acesulfamates, 12 acesulfamates only partially miscible with water, and 12 water-insoluble imides. The crystal structures for two of the chloride salts-(2-hydroxyethyl)dimethylundecyloxymethylammonium chloride and cyclododecyloxymethyl(2-hydroxyethyl)dimethylammonium chloride-were determined. The antimicrobial (cocci, rods, and fungi) activities of the new hydrophilic acesulfamate-based ILs were measured and 12 were found to be active. The alkoxymethyl(2-hydroxyethyl)dimethylammonium acesulfamates have been shown to be insect feeding deterrents and thus open up a new generation of synthetic deterrents based on ionic liquids. The alkoxymethyl(2-decanoyloxyethyl)dimethylammonium bis(trifluoromethylsulfonyl)imides have also been shown to act as fixatives for soft tissues and can furthermore be used as substitutes for formalin and also preservatives for blood.

  17. Cellulose multilayer Membranes manufacture with Ionic liquid

    KAUST Repository

    Livazovic, Sara

    2015-05-09

    Membrane processes are considered energy-efficient for water desalination and treatment. However most membranes are based on polymers prepared from fossil petrochemical sources. The development of multilayer membranes for nanofiltration and ultrafiltration, with thin selective layers of naturally available cellulose has been hampered by the availability of non-aggressive solvents. We propose the manufacture of cellulose membranes based on two approaches: (i) silylation, coating from solutions in tetrahydrofuran, followed by solvent evaporation and cellulose regeneration by acid treatment; (ii) casting from solution in 1-ethyl-3-methylimidazolum acetate ([C2mim]OAc), an ionic liquid, followed by phase inversion in water. By these methods porous supports could be easily coated with semi-crystalline cellulose. The membranes were hydrophilic with contact angles as low as 22.0°, molecular weight cut-off as low as 3000 g mol-1 with corresponding water permeance of 13.8 Lm−2 h−1 bar−1. Self-standing cellulose membranes were also manufactured without porous substrate, using only ionic liquid as green solvent. This membrane was insoluble in water, tetrahydrofuran, hexane, N,N-dimethylformamide, 1-methyl-2-pyrrolidinone and N,N-dimethylacetamide.

  18. Toxicity of ionic liquids prepared from biomaterials.

    Science.gov (United States)

    Gouveia, W; Jorge, T F; Martins, S; Meireles, M; Carolino, M; Cruz, C; Almeida, T V; Araújo, M E M

    2014-06-01

    In search of environmentally-friendly ionic liquids (ILs), 14 were prepared based on the imidazolium, pyridinium and choline cations, with bromide and several amino acids as anions. Good yields were obtained in the synthesis of pyridinium ILs and those prepared from choline and amino acids. Four of the ILs synthesized from choline and the amino acids arginine, glutamine, glutamic acid and cystine are described here for the first time. The toxicity of the synthesized ILs was checked against organisms of various levels of organization: the crustacean Artemia salina; Human cell HeLa (cervical carcinoma); and bacteria with different types of cell wall, Bacillus subtilis and Escherichia coli. The toxicity was observed to depend on both the cation and anion. Choline-amino acid ILs showed a remarkable low toxicity to A. salina and HeLa cell culture, ten times less than imidazolium and pyridinium ILs. None of ionic liquids exhibited marked toxicity to bacteria, and the effect was 2-3 orders of magnitude smaller than that of the antibiotic chloramphenicol. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Anion exchange in ionic liquid mixtures.

    Science.gov (United States)

    Cha, Seoncheol; Kim, Doseok

    2015-11-28

    Advantage of ionic liquids as designer solvents can be maximized by mixing different ionic liquids (ILs) for a possibility of continuous tunability of material properties. The property of these mixed ILs would be determined by their microscopic conformation between cations and anions. The mixtures of two ILs having 1-butyl-3-methylimidaolium cations and different anions were investigated by IR and NMR spectroscopy, utilizing that the vibrational frequencies of the C-H stretching and bending modes of the most acidic proton in the imidazolium ring of the cation and the NMR chemical shift for the corresponding proton were clearly distinct between the ILs having different anions. The IR absorption spectra of the IL mixtures at different concentrations were well-matched to weighted sums of the two spectra of the pure ILs. In contrast, the two distinct peaks in the NMR spectra of the pure ILs coalesced into a single peak, which shifted continuously following the relative portion of two different ILs in the mixture. IR spectroscopy in the optical frequency range seems to take the instantaneous snapshot of the cation-anion interaction, while NMR spectroscopy in the radio-frequency (∼500 MHz) range samples over a much longer timescale, enough for the cation to interact with different anion species in the mixture.

  20. Effect of hydrophobic ionic liquids on petroleum asphaltene dispersion and determination using UV-visible spectroscopy

    Science.gov (United States)

    Rashid, Zeeshan; Wilfredand, Cecilia Devi; Murugesan, Thanabalan

    2017-10-01

    Asphaltene aggregation and flocculation is one of the main problems faced by upstream industry. The aim of this research activity is to explore the effect of synthesized imidazolium and pyridinium based ionic liquids on the prevention of asphaltene aggregation problem in crude oil. In this research, number of hydrophobic and hydrophilic ionic liquids were tested. The investigations were performed for evaluating; the dispersion yield, effect of temperature, effect of stirring time and effect of solvent to flocculant ratio. Analysis were done using UV-visible Spectroscopy. The results depicted that the investigated hydrophobic ionic liquids have the tendency to abate asphaltene aggregation and can be considered as deflocculants.

  1. Thermophysical properties of two ionic liquids based on benzyl imidazolium cation

    Energy Technology Data Exchange (ETDEWEB)

    Deive, Francisco J. [Chemical Engineering, University of Vigo, 36310 Vigo (Spain); Rivas, Miguel A. [Applied Physics Department, University of Vigo, 36310 Vigo (Spain); Rodriguez, Ana, E-mail: aroguez@uvigo.e [Chemical Engineering, University of Vigo, 36310 Vigo (Spain)

    2011-03-15

    Density, refractive index, and dynamic viscosity of two new ionic liquids involving the 1-benzyl-3-methyl imidazolium cation and the common anions chloride and methylsulfate have been determined and correlated as a function of temperature. Volumetric properties for the ionic liquids are calculated from the density and the results are also enclosed. The Lorentz-Lorenz, Dale-Gladstone, Eykman, Oster, Arago-Biot, and Newton equations, as well as a modified Eykman were used to correlate satisfactorily the relation between the densities and refractive indices of the selected ionic liquids. The influence of the benzyl group on the density was compared with other alkyl imidazolium cations and the same anions.

  2. New for old. Password to the thermodynamics of the protic ionic liquids.

    Science.gov (United States)

    Verevkin, Sergey P; Zaitsau, Dzmitry H; Tong, Bo; Welz-Biermann, Urs

    2011-07-28

    Activity coefficients at infinite dilution of some common solvents in a protic ionic liquid ethylammonium nitrate have been measured using well established gas-chromatography-method. This method was possible to apply due to extremely low vapour pressure of ethylammonium nitrate at temperatures below 100 °C. Activity coefficients and separation factors were compared with those for aprotic ionic liquids. A new window for intensive accumulation of thermodynamic properties of protic ionic liquids has been opened. This journal is © the Owner Societies 2011

  3. Corrosion behavior of construction materials for ionic liquid hydrogen compressor

    DEFF Research Database (Denmark)

    Arjomand Kermani, Nasrin; Petrushina, Irina; Nikiforov, Aleksey Valerievich

    2016-01-01

    The corrosion behavior of various commercially available stainless steels and nickel-based alloys as possible construction materials for components which are in direct contact with one of five different ionic liquids was evaluated. The ionic liquids, namely: 1-ethyl-3-methylimidazolium triflate, 1...... liquid hydrogen compressor. An electrochemical cell was specially designed, and steady-state cyclic voltammetry was used to measure the corrosion resistance of the alloys in the ionic liquids at 23 °C, under atmospheric pressure. The results showed a very high corrosion resistance and high stability...... for all the alloys tested. The two stainless steels, AISI 316L and AISI 347 showed higher corrosion resistance compared to AISI 321 in all the ionic liquids tested. It was observed that small addition of molybdenum, tantalum, and niobium to the alloys increased the corrosion stability in the ionic liquids...

  4. Advanced Ionic Liquid Monopropellant for Payload Ascent Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a monopropellant replacement for hydrazine using eutectic mixtures of ionic liquids (EILs). These liquids offer us the ability to tailor fluid...

  5. New frontiers in materials science opened by ionic liquids.

    Science.gov (United States)

    Torimoto, Tsukasa; Tsuda, Tetsuya; Okazaki, Ken-ichi; Kuwabata, Susumu

    2010-03-19

    Ionic liquids (ILs) including ambient-temperature molten salts, which exist in the liquid state even at room temperature, have a long research history. However, their applications were once limited because ILs were considered as highly moisture-sensitive solvents that should be handled in a glove box. After the first synthesis of moisture-stable ILs in 1992, their unique physicochemical properties became known in all scientific fields. ILs are composed solely of ions and exhibit several specific liquid-like properties, e.g., some ILs enable dissolution of insoluble bio-related materials and the use as tailor-made lubricants in industrial applications under extreme physicochemical conditions. Hybridization of ILs and other materials provides quasi-solid materials, which can be used to fabricate highly functional devices. ILs are also used as reaction media for electrochemical and chemical synthesis of nanomaterials. In addition, the negligible vapor pressure of ILs allows the fabrication of electrochemical devices that are operated under ambient conditions, and many liquid-vacuum technologies, such as X-ray photoelectron spectroscopy (XPS) analysis of liquids, electron microscopy of liquids, and sputtering and physical vapor deposition onto liquids. In this article, we review recent studies on ILs that are employed as functional advanced materials, advanced mediums for materials production, and components for preparing highly functional materials.

  6. The Relation between Vaporization Enthalpies and Viscosities: Eyring's Theory Applied to Selected Ionic Liquids.

    Science.gov (United States)

    Bonsa, Anne-Marie; Paschek, Dietmar; Zaitsau, Dzmitry H; Emel'yanenko, Vladimir N; Verevkin, Sergey P; Ludwig, Ralf

    2017-05-19

    Key properties for the use of ionic liquids as electrolytes in batteries are low viscosities, low vapor pressure and high vaporization enthalpies. Whereas the measurement of transport properties is well established, the determination of vaporization enthalpies of these extremely low volatile compounds is still a challenge. At a first glance both properties seem to describe different thermophysical phenomena. However, eighty years ago Eyring suggested a theory which related viscosities and vaporization enthalpies to each other. The model is based on Eyring's theory of absolute reaction rates. Recent attempts to apply Eyring's theory to ionic liquids failed. The motivation of our study is to show that Eyring's theory works, if the assumptions specific for ionic liquids are fulfilled. For that purpose we measured the viscosities of three well selected protic ionic liquids (PILs) at different temperatures. The temperature dependences of viscosities were approximated by the Vogel-Fulcher-Tamann (VFT) relation and extrapolated to the high-temperature regime up to 600 K. Then the VFT-data could be fitted to the Eyring-model. The values of vaporization enthalpies for the three selected PILs predicted by the Eyring model have been very close to the experimental values measured by well-established techniques. We conclude that the Eyring theory can be successfully applied to the chosen set of PILs, if the assumption that ionic pairs of the viscous flow in the liquid and the ionic pairs in the gas phase are similar is fulfilled. It was also noticed that proper transfer of energies can be only derived if the viscosities and the vaporization energies are known for temperatures close to the liquid-gas transition temperature. The idea to correlate easy measurable viscosities of ionic liquids with their vaporization enthalpies opens a new way for a reliable assessment of these thermodynamic properties for a broad range of ionic liquids. © 2017 Wiley-VCH Verlag GmbH & Co. KGa

  7. Environmentally benign methanolysis of polycarbonate to recover bisphenol A and dimethyl carbonate in ionic liquids.

    Science.gov (United States)

    Liu, Fusheng; Li, Zhuo; Yu, Shitao; Cui, Xiao; Ge, Xiaoping

    2010-02-15

    An environmentally friendly strategy for methanolysis of polycarbonate (PC) to recover bisphenol A (BPA) and dimethyl carbonate (DMC) was developed in which PC could be methanolyzed in an ionic liquid without any acid or base catalyst under moderate conditions. The effects of ionic liquid kinds, temperature, time, and methanol dosage on methanolysis results of PC were examined. It was showed that the methanolysis conversion of PC was almost 100% and the yields of both BPA and DMC were over 95% in presence of ionic liquid 1-n-butyl-3-methylimidazolium chloride ([Bmim][Cl]) and under the conditions of m(PC):m(CH(3)OH):m([Bmim][Cl])=2:3:2, reaction temperature 105 degrees C and time 2.5h. After easily separated from the product, the ionic liquid could be reused 8 times without obvious decrease in the conversion of PC and yields of BPA and DMC.

  8. Investigation of 1, 10-Phenanthroline based Ionic Liquids using X ...

    African Journals Online (AJOL)

    However, X-ray photoelectron spectroscopy data (fitting models) for other than 1, 3-dialkyimidazolium based ionic liquids are required and need to be developed. 1, 10-Phenanthrolinium based ionic liquids are among the new compounds reported recently. However, no attempt is observed to investigate the electronic ...

  9. Silica coated ionic liquid templated mesoporous silica nanoparticles ...

    African Journals Online (AJOL)

    Analysis indicates that the particles obtained were in spherical shape with decreasing size as the alkyl chain length of ionic liquid increases. The materials also show increase of BET surface value as the alkyl chain length increases from the range 19 m2/g to 23 m2/g. Keywords: mesoporous silica; ionic liquid, pyridinium; ...

  10. Multi-responsive ionic liquid emulsions stabilized by microgels

    NARCIS (Netherlands)

    Monteillet, H.; Workamp, M.; Li, X.; Schuur, Boelo; Kleijn, J.M.; Leermakers, F.; Sprakel, J.

    2014-01-01

    We present a complete toolbox to use responsive ionic liquid (IL) emulsions for extraction purposes. IL emulsions stabilized by responsive microgels are shown to allow rapid extraction and reversible breaking and re-emulsification. Moreover, by using a paramagnetic ionic liquid, droplets can be

  11. An Ionic Liquid Solution of Chitosan as Organocatalyst

    Directory of Open Access Journals (Sweden)

    René Wilhelm

    2013-11-01

    Full Text Available Chitosan, which is derived from the biopolymer chitin, can be readily dissolved in different ionic liquids. The resulting homogeneous solutions were applied in an asymmetric Aldol reaction. Depending on the type of ionic liquid used, high asymmetric inductions were found. The influence of different additives was also studied. The best results were obtained in [BMIM][Br] without an additive.

  12. Absorption of Flue-Gas Components by Ionic Liquids

    DEFF Research Database (Denmark)

    Kolding, Helene; Thomassen, Peter Langelund; Mossin, Susanne

    2014-01-01

    Gas separation by ionic liquids (ILs) is a promising new research field with several potential applications of industrial interest. Thus cleaning of industrial off gases seems to be attractive by use of ILs and Supported Ionic Liquid Phase (SILP) materials. The potential of selected ILs...

  13. CO2 sorption by supported amino acid ionic liquids

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention concerns the absorption and desorption behaviour of carbon dioxide (CO2) using ionic liquids derived from amino acids adsorbed on porous carrier materials.......The present invention concerns the absorption and desorption behaviour of carbon dioxide (CO2) using ionic liquids derived from amino acids adsorbed on porous carrier materials....

  14. Near-wall molecular ordering of dilute ionic liquids

    NARCIS (Netherlands)

    Jitvisate, Monchai; Seddon, James Richard Thorley

    2017-01-01

    The interfacial behavior of ionic liquids promises tunable lubrication as well as playing an integral role in ion diffusion for electron transfer. Diluting the ionic liquids optimizes bulk parameters, such as electric conductivity, and one would expect dilution to disrupt the near-wall molecular

  15. Reversible physical absorption of SO2 by ionic liquids

    DEFF Research Database (Denmark)

    Huang, Jun; Riisager, Anders; Fehrmann, Rasmus

    2006-01-01

    Ionic liquids can reversibly absorb large amounts of molecular SO2 gas under ambient conditions with the gas captured in a restricted configuration, possibly allowing SO2 to probe the internal cavity structures in ionic liquids besides being useful for SO2 removal in pollution control....

  16. Phase Behavior of Mixtures of Ionic Liquids and Organic Solvents

    DEFF Research Database (Denmark)

    Abildskov, Jens; Ellegaard, Martin Dela; O’Connell, J.P.

    2010-01-01

    A corresponding-states form of the generalized van der Waals equation, previously developed for mixtures of an ionic liquid and a supercritical solute, is here extended to mixtures including an ionic liquid and a solvent (water or organic). Group contributions to characteristic parameters...

  17. Polarity of the interface in ionic liquid in oil microemulsions.

    Science.gov (United States)

    Andújar-Matalobos, María; García-Río, Luis; López-García, Susana; Rodríguez-Dafonte, Pedro

    2011-11-01

    Ionic liquid based microemulsions were characterized by absorption solvatochromic shifts, (1)H NMR and kinetic measurements in order to investigate the properties of the ionic liquid within the restricted geometry provided by microemulsions and the interactions of the ionic liquid with the interface. Experimental results show a significant difference between the interfaces of normal water and the new ionic liquid microemulsions. Absorption solvatochromic shift experiments and kinetic studies on the aminolysis of 4-nitrophenyl laurate by n-decylamine show that the polarity at the interface of the ionic liquid in oil microemulsions (IL/O) is higher than at the interface of water in oil microemulsions (W/O) despite the fact that the polarity of [bmim][BF(4)(-)] is lower than the polarity of water. (1)H NMR experiments showed that an increase in the ionic liquid content of the microemulsion led to an increase in the interaction between [bmim][BF(4)(-)] and TX-100. The reason for the higher polarity of the microemulsions with the ionic liquid can be explained in terms of the incorporation of higher levels of the ionic liquid at the interface of the microemulsions, as compared to water in the traditional systems. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Combined reactions and separations using ionic liquids and carbon dioxide

    NARCIS (Netherlands)

    Kroon, M.C.

    2006-01-01

    A new and general type of process for the chemical industry is presented using ionic liquids and supercritical carbon dioxide as combined reaction and separation media. In this process, the carbon dioxide pressure controls the miscibility of reactants, products, catalyst and ionic liquid, enabling

  19. Investigation of hybrid molecular material prepared by ionic liquid ...

    Indian Academy of Sciences (India)

    Wintec

    1-Butyl 3-methyl imidazolium bromide; molecular material; phosphotungstic acid; near IR. 1. Introduction. Ionic liquids are gaining importance in the synthesis of hybrid materials. 1. The 'ionic liquid' moniker is used for low melting point salts that contain organic cations. 2 ... class of solid acid catalytic materials with Brønsted.

  20. Ionic Liquids and Green Chemistry: A Lab Experiment

    Science.gov (United States)

    Stark, Annegret; Ott, Denise; Kralisch, Dana; Kreisel, Guenter; Ondruschka, Bernd

    2010-01-01

    Although ionic liquids have been investigated as solvents for many applications and are starting to be used in industrial processes, only a few lab experiments are available to introduce students to these materials. Ionic liquids have been discussed in the context of green chemistry, but few investigations have actually assessed the degree of…

  1. Ionic Liquid-Based Ultrasonic/Microwave-Assisted Extraction of ...

    African Journals Online (AJOL)

    Purpose: To develop a more green, efficient and low cost process for the extraction of steroidal saponins from Dioscorea Zingiberensis C. H. Wright. Methods: Six kinds of ionic liquids with different cations and anions were evaluated. In addition, the extraction parameters of the ionic liquid based ultrasonic/microwave ...

  2. Synthesis of Metal-Rich Compounds of Group 15 Elements in Lewis-Acidic Ionic Liquids

    OpenAIRE

    Groh, Matthias Friedrich

    2017-01-01

    Chemical synthesis of materials is facing enormous challenges at the present time. The necessary transition toward more sustainable economic processes requires new materials as well as optimized production of well-established materials. However, inorganic materials (e.g., ceramics or alloys) are typically produced industrially by high-temperature processes at up to 2000 °C. A relatively new approach for inorganic synthesis is based on so-called ionic liquids. Ionic liquids (ILs) — often d...

  3. Ionic liquid-stabilized non-spherical gold nanofluids synthesized using a one-step method

    OpenAIRE

    Zhang, Hao; Cui, Hua; Yao, Shiwei; Zhang, Kelong; Tao, Haikun; Meng, Haibo

    2012-01-01

    Ionic liquid (IL)-stabilized non-spherical gold nanofluids have been synthesized by a one-step method in aqueous solution. The whole reaction proceeded in room temperature. In the presence of amino-functionalized ionic liquids, gold nanofluids with long-wave surface plasmon resonance (SPR) absorption (>600 nm) could be obtained by adopting tannic acid as the reductant. The specific SPR absorption was related to the non-spherical gold nanoparticles including gold triangle, decahedra, and icosa...

  4. Fuel Cells Using the Protic Ionic Liquid and Rotator Phase Solid Electrolyte Principles

    Science.gov (United States)

    2008-02-13

    Talk “High temperature Polymer Electrolyte Membrane Fuel Cells ( HT -PEMFCs) for Portable Power in Large-Scale Energy Storage Devices”, Paper Number 195...Protic ionic liquids and the PEM fuel cell , 2nd International Congress on Ionic Liquids, poster session, #3P07-081, Yokohama, Japan, August 5-10...Membrane Fuel Cells ( HT -PEMFCs) for Portable Power in Large-Scale Energy Storage Devices”, Paper Number 195, 212th Meeting of the Electrochemical

  5. Ionic Liquids and New Proton Exchange Membranes for Fuel Cells

    Science.gov (United States)

    Belieres, Jean-Philippe

    2004-01-01

    There is currently a great surge of activity in fuel cell research as laboratories across the world seek to take advantage of the high energy capacity provided by &el cells relative to those of other portable electrochemical power systems. Much of this activity is aimed at high temperature fie1 cells, and a vital component of such &el cells must be the availability of a high temperature stable proton-permeable membrane. NASA Glenn Research Center is greatly involved in developing this technology. Other approaches to the high temperature fuel cell involve the use of single- component or almost-single-component electrolytes that provide a path for protons through the cell. A heavily researched case is the phosphoric acid fuel cell, in which the electrolyte is almost pure phosphoric acid and the cathode reaction produces water directly. The phosphoric acid fie1 cell delivers an open circuit voltage of 0.9 V falling to about 0.7 V under operating conditions at 170 C. The proton transport mechanism is mainly vehicular in character according to the viscosity/conductance relation. Here we describe some Proton Transfer Ionic Liquids (PTILs) with low vapor pressure and high temperature stability that have conductivities of unprecedented magnitude for non-aqueous systems. The first requirement of an ionic liquid is that, contrary to experience with most liquids consisting of ions, it must have a melting point that is not much above room temperature. The limit commonly suggested is 100 C. PTILs constitute an interesting class of non-corrosive proton-exchange electrolyte, which can serve well in high temperature (T = 100 - 250 C) fuel cell applications. We will present cell performance data showing that the open circuit voltage output, and the performance of a simple H2(g)Pt/PTIL/Pt/O2(g) fuel cell may be superior to those of the equivalent phosphoric acid electrolyte fuel cell both at ambient temperature and temperatures up to and above 200 C. My work at NASA Glenn Research

  6. Electrochemical transistors with ionic liquids for enzymatic sensing

    Science.gov (United States)

    Fraser, Kevin J.; Yang, Sang Yoon; Cicoira, Fabio; Curto, Vincenzo F.; Byrne, Robert; Benito-Lopez, Fernando; Khodagholy, Dion; Owens, Róisín M.; Malliaras, George G.; Diamond, Dermot

    2011-10-01

    Over the past decade conducting polymer electrodes have played an important role in bio-sensing and actuation. Recent developments in the field of organic electronics have made available a variety of devices that bring unique capabilities at the interface with biology. One example is organic electrochemical transistors (OECTs) that are being developed for a variety of bio-sensing applications, including the detection of ions, and metabolites, such as glucose and lactate. Room temperature ionic liquids (RTILs) are organic salts, which are liquid at ambient temperature. Their nonvolatile character and thermal stability makes them an attractive alternative to conventional organic solvents. Here we report an enzymatic sensor based on an organic electro-chemical transistor with RTIL's as an integral part of its structure and as an immobilization medium for the enzyme and the mediator. Further investigation shows that these platforms can be incorporated into flexible materials such as carbon cloth and can be utilized for bio-sensing. The aim is to incorporate the overall platform in a wearable sensor to improve athlete performance with regards to training. In this manuscript an introduction to ionic liquids (ILs), IL - enzyme mixtures and a combination of these novel materials being used on OECTs are presented.

  7. Investigation of solvation of iron nanoclusters in ionic liquid 1-butyl-1,1,1-trimethylammonium methane sulfonate using molecular dynamics simulations: Effect of cluster size at different temperatures.

    Science.gov (United States)

    Abbaspour, Mohsen; Akbarzadeh, Hamed; Yousefi, Parnian; Razmkhah, Mohammad

    2017-10-15

    The systems composed of metal nanoclusters in ionic liquids are relevant for applications in lubrication, electrochemical devices, catalysis, and chemical processes. The mechanism of solvation and interactions of these systems are not understood at present. In this work, we have simulated iron nanoclusters with different sizes in ionic liquid 1-butyl-1,1,1-trimethylammonium methane sulfonate [N1114][C1SO3] at two temperatures (300 and 500K) and at atmospheric pressure. We have investigated the effects of cluster size and the temperature on some of the thermodynamics, structural and dynamical properties of the systems. Our results also show that the absolute value of solvation energy increases as the nanocluster size increases. Also the absolute solvation energy increases as the temperature increases. It is also shown that the effect of the cluster size is much more than the effect of the temperature. Our structural investigations indicate at least two shells (a double layer) around the nanocluster and the anions are closer to the cluster surface than the cations. The self-diffusion coefficients of cations, anions, and iron clusters have been also presented and discussed in this work. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Ionic liquid based dispersive liquid-liquid microextraction for the extraction of pesticides from bananas.

    Science.gov (United States)

    Ravelo-Pérez, Lidia M; Hernández-Borges, Javier; Asensio-Ramos, María; Rodríguez-Delgado, Miguel Angel

    2009-10-23

    This paper describes a dispersive liquid-liquid microextraction (DLLME) procedure using room temperature ionic liquids (RTILs) coupled to high-performance liquid chromatography with diode array detection capable of quantifying trace amounts of eight pesticides (i.e. thiophanate-methyl, carbofuran, carbaryl, tebuconazole, iprodione, oxyfluorfen, hexythiazox and fenazaquin) in bananas. Fruit samples were first homogenized and extracted (1g) with acetonitrile and after suitable evaporation and reconstitution of the extract in 10 mL of water, a DLLME procedure using 1-hexyl-3-methylimidazolium hexafluorophosphate ([C(6)MIM][PF(6)]) as extraction solvent was used. Experimental conditions affecting the DLLME procedure (sample pH, sodium chloride percentage, ionic liquid amount and volume of disperser solvent) were optimized by means of an experimental design. In order to determine the presence of a matrix effect, calibration curves for standards and fortified banana extracts (matrix matched calibration) were studied. Mean recovery values of the extraction of the pesticides from banana samples were in the range of 69-97% (except for thiophanate-methyl and carbofuran, which were 53-63%) with a relative standard deviation lower than 8.7% in all cases. Limits of detection achieved (0.320-4.66 microg/kg) were below the harmonized maximum residue limits established by the European Union (EU). The proposed method, was also applied to the analysis of this group of pesticides in nine banana samples taken from the local markets of the Canary Islands (Spain). To the best of our knowledge, this is the first application of RTILs as extraction solvents for DLLME of pesticides from samples different than water.

  9. Pesticide extraction from table grapes and plums using ionic liquid based dispersive liquid-liquid microextraction.

    Science.gov (United States)

    Ravelo-Pérez, Lidia M; Hernández-Borges, Javier; Herrera-Herrera, Antonio V; Rodríguez-Delgado, Miguel Angel

    2009-12-01

    Room temperature ionic liquids (RTILs) have been used as extraction solvents in dispersive liquid-liquid microextraction (DLLME) for the determination of eight multi-class pesticides (i.e. thiophanate-methyl, carbofuran, carbaryl, tebuconazole, iprodione, oxyfluorfen, hexythiazox, and fenazaquin) in table grapes and plums. The developed method involves the combination of DLLME and high-performance liquid chromatography with diode array detection. Samples were first homogenized and extracted with acetonitrile. After evaporation and reconstitution of the extract in water containing sodium chloride, a quick DLLME procedure that used the ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate ([C(6)MIM][PF(6)]) and methanol was developed. The RTIL dissolved in a very small volume of acetonitrile was directed injected in the chromatographic system. The comparison between the calibration curves obtained from standards and from spiked sample extracts (matrix-matched calibration) showed the existence of a strong matrix effect for most of the analyzed pesticides. A recovery study was also developed with five consecutive extractions of the two types of fruits spiked at three concentration levels. Mean recovery values were in the range of 72-100% for table grapes and 66-105% for plum samples (except for thiophanate-methyl and carbofuran, which were 64-75% and 58-66%, respectively). Limits of detection (LODs) were in the range 0.651-5.44 microg/kg for table grapes and 0.902-6.33 microg/kg for plums, representing LODs below the maximum residue limits (MRLs) established by the European Union in these fruits. The potential of the method was demonstrated by analyzing 12 commercial fruit samples (six of each type).

  10. Ternary liquid-liquid equilibria for mixtures of toluene + n-heptane + an ionic liquid

    NARCIS (Netherlands)

    Meindersma, G.W.; Podt, J.G.; de Haan, A.B.

    2006-01-01

    This research has been focused on a study of sulfolane and four ionic liquids as solvents in liquid–liquid extraction. Liquid–liquid equilibria data were obtained for mixtures of (sulfolane or 4-methyl-N-butylpyridinium tetrafluoroborate ([mebupy]BF4) or 1-ethyl-3-methylimidazolium ethylsulfate

  11. New triazolium based ionic liquid crystals

    Energy Technology Data Exchange (ETDEWEB)

    Stappert, Kathrin [Ruhr-Universitat Bochum; Unal, Derya [Ruhr-Universitat Bochum; Mallick, Bert [Ruhr Universitat Bochum; Mudring, Anja-Verena [Ames Laboratory

    2014-01-01

    A set of novel 1,2,3-triazolium based ionic liquid crystals was synthesized and their mesomorphic behaviour studied by DSC (differential scanning calorimetry), POM (polarizing optical microscopy) and SAXS (small angle X-ray scattering). Beside the variation of the chain length (C10, C12 and C14) at the 1,2,3-triazolium cation also the anion has been varied (Br-, I-, I3-, BF4-, SbF6-, N(CN)2-, Tf2N-) to study the influence of ion size, symmetry and H-bonding capability on the mesophase formation. Interestingly, for the 1,3-didodecyl-1,2,3-triazolium cation two totally different conformations were found in the crystal structure of the bromide (U-shaped) and the triiodide (rod shaped).

  12. Metsulfuron-methyl-based herbicidal ionic liquids.

    Science.gov (United States)

    Pernak, Juliusz; Niemczak, Michał; Shamshina, Julia L; Gurau, Gabriela; Głowacki, Grzegorz; Praczyk, Tadeusz; Marcinkowska, Katarzyna; Rogers, Robin D

    2015-04-08

    Ten sulfonylurea-based herbicidal ionic liquids (HILs) were prepared by combining the metsulfuron-methyl anion with various cation types including quaternary ammonium ([bis(2-hydroxyethyl)methyloleylammonium](+), [2-hydroxyethyltrimethylammonium](+)), pyridinium ([1-dodecylpyridinium](+)), piperidinium ([1-methyl-1-propylpiperidinium](+)), imidazolium ([1-allyl-3-methylimidazolium](+), [1-butyl-3-methylimidazolium](+)), pyrrolidinium ([1-butyl-1-methylpyrrolidinium](+)), morpholinium ([4-decyl-4-methylmorpholinium](+)), and phosphonium ([trihexyltetradecylphosphonium](+) and [tetrabutylphosphonium](+)). Their herbicidal efficacy was studied in both greenhouse tests and field trials. Preliminary results for the greenhouse tests showed at least twice the activity for all HILs when compared to the activity of commercial Galmet 20 SG, with HILs with phosphonium cations being the most effective. The results of two-year field studies showed significantly less enhancement of activity than observed in the greenhouse; nonetheless, it was found that the herbicidal efficacy was higher than that of the commercial analog, and efficacy varied depending on the plant species.

  13. Gold Functionalized Supported Ionic Liquids Catalyst for CO Oxidation

    Directory of Open Access Journals (Sweden)

    Svetlana Ivanova

    2011-11-01

    Full Text Available The present study tries to give an insight to the combination of the homogeneous and heterogeneous catalytic properties in a new class of materials. Well dispersed gold nanoparticles on an ionic liquid layer supported on a mineral carrier have been prepared. This work is concentrated on the characterizations and understanding of the interactions between all the components of the catalytic system. The application of the materials in the reaction of oxidation of carbon monoxide shows rather unexpected results—a good catalytic activity completely independent of the temperature.

  14. Synthesis and properties of trigeminal tricationic ionic liquids.

    Science.gov (United States)

    Pernak, Juliusz; Skrzypczak, Andrzej; Lota, Grzegorz; Frackowiak, Elzbieta

    2007-01-01

    Novel trigeminal tricationic ionic liquids (TTILs) have been successfully synthesized in high yields by means of Menschutkin quaternization via an S(N)1 mechanism. This reaction presents a new convenient method for transforming glycerol into multifunctional compounds. The physical properties of a series of TTILs were characterized by using a variety of techniques. The prepared salts were tested for antimicrobial activity. Electrochemical characterization of TTILs was also performed, which allowed the estimation of the conductivity of these new compounds, to establish their electrochemical stability window and capacitance properties over a wide range of temperatures. A good correlation of the physical properties of TTILs with capacitance values was observed.

  15. Physical Chemistry of Reaction Dynamics in Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Margulis, Claudio Javier [Univ. of Iowa, Iowa City, IA (United States)

    2016-10-31

    The Margulis group BES funded research at the University of Iowa is part of a broader collaborative effort that includes the groups of Blank (U. Minnesota), Castner (Rutgers U.), Maroncelli (Penn. State U.) and Wishart (BNL). The goal of this group of PIs is to better understand from an experimental and a theoretical perspective different aspects of photo-initiated electron transfer processes in a set of different room-temperature ionic-liquid systems. The Margulis contribution is theoretical and computational. Details are presented in the attached documentation.

  16. Temperature-controlled ionic liquid-based ultrasound-assisted microextraction for preconcentration of trace quantity of cadmium and nickel by using organic ligand in artificial saliva extract of smokeless tobacco products

    Science.gov (United States)

    Arain, Sadaf Sadia; Kazi, Tasneem Gul; Arain, Asma Jabeen; Afridi, Hassan Imran; Baig, Jameel Ahmed; Brahman, Kapil Dev; Naeemullah; Arain, Salma Aslam

    2015-03-01

    A new approach was developed for the preconcentration of cadmium (Cd) and nickel (Ni) in artificial saliva extract of dry snuff (brown and black) products using temperature-controlled ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction (TIL-UDLLμE) followed by electrothermal atomic absorption spectrometry (ETAAS). The Cd and Ni were complexed with ammonium pyrrolidinedithiocarbamate (APDC), extracted in ionic liquid drops, 1-butyl-3-methylimidazolium hexafluorophosphate [C4MIM][PF6]. The multivariate strategy was applied to estimate the optimum values of experimental variables influence the % recovery of analytes by TIL-UDLLμE method. At optimum experimental conditions, the limit of detection (3s) were 0.05 and 0.14 μg L-1 while relative standard deviations (% RSD) were 3.97 and 3.55 for Cd and Ni respectively. After extraction, the enhancement factors (EF) were 87 and 79 for Cd and Ni, respectively. The RSD for six replicates of 10 μg L-1 Cd and Ni were 3.97% and 3.55% respectively. To validate the proposed method, certified reference material (CRM) of Virginia tobacco leaves was analyzed, and the determined values of Cd and Ni were in good agreement with the certified values. The concentration of Cd and Ni in artificial saliva extracts corresponds to 39-52% and 21-32%, respectively, of the total contents of both elements in dry brown and black snuff products.

  17. Energy Efficient Electrochromic Windows Incorporating Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Cheri Boykin; James Finley; Donald Anthony; Julianna Knowles; Richard Markovic; Michael Buchanan; Mary Ann Fuhry; Lisa Perrine

    2008-11-30

    One approach to increasing the energy efficiency of windows is to control the amount of solar radiation transmitted through a window by using electrochromic technology. What is unique about this project is that the electrochromic is based on the reduction/oxidation reactions of cathodic and anodic organic semi-conducting polymers using room temperature ionic liquids as ion transport electrolytes. It is believed that these types of coatings would be a lower cost alternative to traditional all inorganic thin film based electrochromic technologies. Although there are patents1 based on the proposed technology, it has never been reduced to practice and thoroughly evaluated (i.e. durability and performance) in a window application. We demonstrate that by using organic semi-conductive polymers, specific bands of the solar spectrum (specifically visible and near infrared) can be targeted for electrochemical variable transmittance responsiveness. In addition, when the technology is incorporated into an insulating glass unit, the energy parameters such as the solar heat gain coefficient and the light to solar gain ratio are improved over that of a typical insulating glass unit comprised of glass with a low emissivity coating. A minimum of {approx}0.02 quads of energy savings per year with a reduction of carbon emissions for electricity of {approx}320 MKg/yr benefit is achieved over that of a typical insulating glass unit including a double silver low-E coating. Note that these values include a penalty in the heating season. If this penalty is removed (i.e. in southern climates or commercial structures where cooling is predominate year-round) a maximum energy savings of {approx}0.05 quad per year and {approx}801 MKg/yr can be achieved over that of a typical insulating glass unit including a double silver low-E coating. In its current state, the technology is not durable enough for an exterior window application. The primary downfall is that the redox chemistry fails to

  18. Comparing two tetraalkylammonium ionic liquids. II. Phase transitions

    Science.gov (United States)

    Lima, Thamires A.; Paschoal, Vitor H.; Faria, Luiz F. O.; Ribeiro, Mauro C. C.; Ferreira, Fabio F.; Costa, Fanny N.; Giles, Carlos

    2016-06-01

    Phase transitions of the ionic liquids n-butyl-trimethylammonium bis(trifluoromethanesulfonyl)imide, [N1114][NTf2], and methyl-tributylammonium bis(trifluoromethanesulfonyl)imide, [N1444][NTf2], were investigated by differential scanning calorimetry (DSC), X-ray diffraction (XRD) measurements, and Raman spectroscopy. XRD and Raman spectra were obtained as a function of temperature at atmospheric pressure, and also under high pressure at room temperature using a diamond anvil cell (DAC). [N1444][NTf2] experiences glass transition at low temperature, whereas [N1114][NTf2] crystallizes or not depending on the cooling rate. Both the ionic liquids exhibit glass transition under high pressure. XRD and low-frequency Raman spectra provide a consistent physical picture of structural ordering-disordering accompanying the thermal events of crystallization, glass transition, cold crystallization, pre-melting, and melting. Raman spectra in the high-frequency range of some specific cation and anion normal modes reveal conformational changes of the molecular structures along phase transitions.

  19. Comparing two tetraalkylammonium ionic liquids. II. Phase transitions

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Thamires A.; Paschoal, Vitor H.; Faria, Luiz F. O.; Ribeiro, Mauro C. C., E-mail: mccribei@iq.usp.br [Laboratório de Espectroscopia Molecular, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, CP 26077, CEP 05513-970 São Paulo, SP (Brazil); Ferreira, Fabio F.; Costa, Fanny N. [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, SP (Brazil); Giles, Carlos [Depto. de Física da Matéria Condensada, Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, 13083-859 Campinas, SP (Brazil)

    2016-06-14

    Phase transitions of the ionic liquids n-butyl-trimethylammonium bis(trifluoromethanesulfonyl)imide, [N{sub 1114}][NTf{sub 2}], and methyl-tributylammonium bis(trifluoromethanesulfonyl)imide, [N{sub 1444}][NTf{sub 2}], were investigated by differential scanning calorimetry (DSC), X-ray diffraction (XRD) measurements, and Raman spectroscopy. XRD and Raman spectra were obtained as a function of temperature at atmospheric pressure, and also under high pressure at room temperature using a diamond anvil cell (DAC). [N{sub 1444}][NTf{sub 2}] experiences glass transition at low temperature, whereas [N{sub 1114}][NTf{sub 2}] crystallizes or not depending on the cooling rate. Both the ionic liquids exhibit glass transition under high pressure. XRD and low-frequency Raman spectra provide a consistent physical picture of structural ordering-disordering accompanying the thermal events of crystallization, glass transition, cold crystallization, pre-melting, and melting. Raman spectra in the high-frequency range of some specific cation and anion normal modes reveal conformational changes of the molecular structures along phase transitions.

  20. Ionic liquids and derived materials for lithium and sodium batteries.

    Science.gov (United States)

    Yang, Qiwei; Zhang, Zhaoqiang; Sun, Xiao-Guang; Hu, Yong-Sheng; Xing, Huabin; Dai, Sheng

    2018-02-02

    The ever-growing demand for advanced energy storage devices in portable electronics, electric vehicles and large scale power grids has triggered intensive research efforts over the past decade on lithium and sodium batteries. The key to improve their electrochemical performance and enhance the service safety lies in the development of advanced electrode, electrolyte, and auxiliary materials. Ionic liquids (ILs) are liquids consisting entirely of ions near room temperature, and are characterized by many unique properties such as ultralow volatility, high ionic conductivity, good thermal stability, low flammability, a wide electrochemical window, and tunable polarity and basicity/acidity. These properties create the possibilities of designing batteries with excellent safety, high energy/power density and long-term stability, and also provide better ways to synthesize known materials. IL-derived materials, such as poly(ionic liquids), ionogels and IL-tethered nanoparticles, retain most of the characteristics of ILs while being endowed with other favourable features, and thus they have received a great deal of attention as well. This review provides a comprehensive review of the various applications of ILs and derived materials in lithium and sodium batteries including Li/Na-ion, dual-ion, Li/Na-S and Li/Na-air (O2) batteries, with a particular emphasis on recent advances in the literature. Their unique characteristics enable them to serve as advanced resources, medium, or ingredient for almost all the components of batteries, including electrodes, liquid electrolytes, solid electrolytes, artificial solid-electrolyte interphases, and current collectors. Some thoughts on the emerging challenges and opportunities are also presented in this review for further development.

  1. Phase behavior and ionic conductivity of concentrated solutions of polystyrene-poly(ethylene oxide) diblock copolymers in an ionic liquid.

    Science.gov (United States)

    Simone, Peter M; Lodge, Timothy P

    2009-12-01

    Concentrated solutions of poly(styrene-b-ethylene oxide) (PS-PEO) diblock copolymers were prepared using the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [EMI][TFSI] as the solvent. The self-assembled microstructures adopted by the copolymer solutions have been characterized using small-angle X-ray scattering. Lyotropic mesophase transitions were observed, with a progression from hexagonally packed cylinders of PEO, to lamellae, to hexagonally packed cylinders of PS upon increasing [EMI][TFSI] content. The change in lamellar domain spacing with ionic liquid concentration was found to be comparable to that reported for other block copolymers in strongly selective solvents. The ionic conductivity of the concentrated PS-PEO/[EMI][TFSI] solutions was measured via impedance spectroscopy, and ranged from 1 x 10(-7) to 1 x 10(-3) S/cm at temperatures from 25 - 100 degrees C. Additionally, the ionic conductivity of the solutions was found to increase with both ionic liquid concentration and molecular weight of the PEO blocks. The ionic conductivity of PEO homopolymer/[EMI][TFSI] solutions was also measured in order to compare the conductivity of the PS-PEO solutions to the expected limit for a lamellar sample with randomly oriented microstructure grains.

  2. Raman Spectroscopy and Ab-Initio Model Calculations on Ionic Liquids

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    2007-01-01

    A review of the recent developments in the study and understanding of room temperature ionic liquids are given. An intimate picture of how and why these liquids are not crystals at ambient conditions is attempted, based on evidence from crystallographical results combined with vibrational...... spectroscopy and ab-initio molecular orbital calculations. A discussion is given, based mainly on some recent FT-Raman spectroscopic results on the model ionic liquid system of 1-butyl-3-methylimidazolium ([C4mim][X]) salts. The rotational isomerism of the [C4mim]þ cation is described: the presence of anti...... and gauche conformers that has been elucidated in remarkable papers by Hamaguchi et al. Such presence of a conformational equilibrium seems to be a general feature of the room temperature liquids. Then the ‘‘localized structure features’’ that apparently exist in ionic liquids are described. It is hoped...

  3. Composite Electrolytes for Lithium Batteries: Ionic Liquids in APTES Crosslinked Polymers

    Science.gov (United States)

    Tigelaar, Dean M.; Meador, Mary Ann B.; Bennett, William R.

    2007-01-01

    Solvent free polymer electrolytes were made consisting of Li(+) and pyrrolidinium salts of trifluoromethanesulfonimide added to a series of hyperbranched poly(ethylene oxide)s (PEO). The polymers were connected by triazine linkages and crosslinked by a sol-gel process to provide mechanical strength. The connecting PEO groups were varied to help understand the effects of polymer structure on electrolyte conductivity in the presence of ionic liquids. Polymers were also made that contain poly(dimethylsiloxane) groups, which provide increased flexibility without interacting with lithium ions. When large amounts of ionic liquid are added, there is little dependence of conductivity on the polymer structure. However, when smaller amounts of ionic liquid are added, the inherent conductivity of the polymer becomes a factor. These electrolytes are more conductive than those made with high molecular weight PEO imbibed with ionic liquids at ambient temperatures, due to the amorphous nature of the polymer.

  4. Transesterification of waste oil to biodiesel using Brønsted acid ionic liquid as catalyst

    Directory of Open Access Journals (Sweden)

    C. Xie

    2013-05-01

    Full Text Available Brønsted acid ionic liquids were employed for the preparation of biodiesel using waste oil as the feedstock. It was found that IL 1–(3–sulfonic acidpropyl–3–methylimidazole hydrosulfate–[HO3S-pmim]HSO4 was an efficient catalyst for the reaction under the optimum conditions: n(oil:n(methanol 1:12, waste oil 15.0 g, ionic liquid 2.0 g, reaction temperature 120 oC and reaction time 8 h, the yield of biodiesel was more than 96%. The reusability of the ionic liquid was also investigated. When the ionic liquid was repeatedly used for five times, the yield of product was still more than 93%. Therefore, an efficient and environmentally friendly catalyst was provided for the synthesis of biodiesel from waste oils.

  5. Np(IV) complex with task-specific ionic liquid based on CMPO: first cyclic voltammetric study

    NARCIS (Netherlands)

    Sengupta, A; Murali, M.S.; Mohapatra, P.K.; Iqbal, M.; Huskens, Jurriaan; Verboom, Willem

    2015-01-01

    A cyclic voltammetric study on Np(IV) complexes with task-specific ionic liquid with 3-dodecylimidazolium cation appended with diphenylcarbamoylmethylphosphine oxide and bis(trifluoromethyl-sulfonyl)-imide anion dissolved in the room temperature ionic liquid 1-butyl-3-methylimidazolium

  6. A novel CMPO-functionalized task specific ionic liquid: Synthesis, extraction and spectroscopic investigations of actinide and lanthanide complexes

    NARCIS (Netherlands)

    Mohapatra, P.K.; Kandwal, P.; Iqbal, M.; Huskens, Jurriaan; Murali, M.S.; Verboom, Willem

    2013-01-01

    A novel CMPO (carbamoylmethylphosphine oxide) based task specific ionic liquid (TSIL) with an NTf2− counter anion was synthesized and evaluated for actinide/lanthanide extraction from acidic feed solutions using several room temperature ionic liquids (RTILs). The extraction data were compared with

  7. Shock Wave Energy Dissipation using Polymerized Ionic Liquids

    Science.gov (United States)

    Lee, Jaejun; Ren, Yi; Evans, Christopher; Moore, Jeffrey; Sottos, Nancy

    2017-06-01

    Polymerized ionic liquids composed of alkyl-imidazolium cations and bis(trifluoromethane)sulfonamide anions exhibit intriguing shock wave energy absorption performance. In prior work, we observed a shock-induced disorder-to-order change in network forming ionic liquids. We hypothesize that this shock-induced ordering is strongly associated with the microstructure of the ionic liquids. Polymerized ionic liquids, which have similar microstructures but slower relaxation times compared to the ionic liquids, are prepared to demonstrate the ordering transition mechanism and to exploit relaxation processes for the energy dissipation. By employing size-tunable alkyl backbone spacers between cations, we explore the effect of the relative microstructural heterogeneity on the activation of shock-induced ordering. Relaxation time, which is adjustable by the alkyl spacer length, also plays an important role in the energy dissipation process. Absorption properties of a series of thin film (ca. 50 μm) polymerized ionic liquids are evaluated using a laser-induced shock wave testing protocol. Superior shock wave mitigating performance of polymerized ionic liquids was achieved compared to polyurea films.

  8. Soft Ionization of Thermally Evaporated Hypergolic Ionic Liquid Aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Christine J. [Univ. of California, Berkeley, CA (United States); Liu, Chen-Lin [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Harmon, Christopher W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Strasser, Daniel [Univ. of California, Berkeley, CA (United States); Golan, Amir [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kostko, Oleg [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chambreau, Steven D. [Edwards Air Force Base, ERC Inc., CA (United States); Vaghjiani, Ghanshyam L. [Air Force Research Laboratory, Edwards Air Force Base, CA (United States); Leone, Stephen R. [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2011-04-20

    Isolated ion pairs of a conventional ionic liquid, 1-Ethyl-3-Methyl-Imidazolium Bis(trifluoromethylsulfonyl)imide ([Emim+][Tf2N–]), and a reactive hypergolic ionic liquid, 1-Butyl-3-Methyl-Imidazolium Dicyanamide ([Bmim+][Dca–]), are generated by vaporizing ionic liquid submicrometer aerosol particles for the first time; the vaporized species are investigated by dissociative ionization with tunable vacuum ultraviolet (VUV) light, exhibiting clear intact cations, Emim+ and Bmim+, presumably originating from intact ion pairs. Mass spectra of ion pair vapor from an effusive source of the hypergolic ionic liquid show substantial reactive decomposition due to the internal energy of the molecules emanating from the source. Also, hotoionization efficiency curves in the near threshold ionization region of isolated ion pairs of [Emim+][Tf2N] ionic liquid vapor are compared for an aerosol source and an effusive source, revealing changes in the appearance energy due to the amount of internal energy in the ion pairs. The aerosol source has a shift to higher threshold energy (~0.3 eV), attributed to reduced internal energy of the isolated ion pairs. Lastly, the method of ionic liquid submicrometer aerosol particle vaporization, for reactive ionic liquids such as hypergolic species, is a convenient, thermally “cooler” source of isolated intact ion pairs in the gas phase compared to effusive sources.

  9. Soft ionization of thermally evaporated hypergolic ionic liquid aerosols

    Energy Technology Data Exchange (ETDEWEB)

    University of California; ERC, Incorporated, Edwards Air Force Base; Air Force Research Laboratory, Edwards Air Force Base; National Synchrotron Radiation Research Center (NSRRC); Institute of Chemistry, Hebrew University; Koh, Christine J.; Liu, Chen-Lin; Harmon, Christopher W.; Strasser, Daniel; Golan, Amir; Kostko, Oleg; Chambreau, Steven D.; Vaghjiani, Ghanshyam L.; Leone, Stephen R.

    2011-07-19

    Isolated ion pairs of a conventional ionic liquid, 1-Ethyl-3-Methyl-Imidazolium Bis(trifluoromethylsulfonyl)imide ([Emim+][Tf2N?]), and a reactive hypergolic ionic liquid, 1-Butyl-3-Methyl-Imidazolium Dicyanamide ([Bmim+][Dca?]), are generated by vaporizing ionic liquid submicron aerosol particles for the first time; the vaporized species are investigated by dissociative ionization with tunable vacuum ultraviolet (VUV) light, exhibiting clear intact cations, Emim+ and Bmim+, presumably originating from intact ion pairs. Mass spectra of ion pair vapor from an effusive source of the hypergolic ionic liquid show substantial reactive decomposition due to the internal energy of the molecules emanating from the source. Photoionization efficiency curves in the near threshold ionization region of isolated ion pairs of [Emim+][Tf2N?]ionic liquid vapor are compared for an aerosol source and an effusive source, revealing changes in the appearance energy due to the amount of internal energy in the ion pairs. The aerosol source has a shift to higher threshold energy (~;;0.3 eV), attributed to reduced internal energy of the isolated ion pairs. The method of ionic liquid submicron aerosol particle vaporization, for reactive ionic liquids such as hypergolic species, is a convenient, thermally ?cooler? source of isolated intact ion pairs in the gas phase compared to effusive sources.

  10. Understanding the impact of the central atom on the ionic liquid behavior: Phosphonium vs ammonium cations

    Science.gov (United States)

    Carvalho, Pedro J.; Ventura, Sónia P. M.; Batista, Marta L. S.; Schröder, Bernd; Gonçalves, Fernando; Esperança, José; Mutelet, Fabrice; Coutinho, João A. P.

    2014-02-01

    The influence of the cation's central atom in the behavior of pairs of ammonium- and phosphonium-based ionic liquids was investigated through the measurement of densities, viscosities, melting temperatures, activity coefficients at infinite dilution, refractive indices, and toxicity against Vibrio fischeri. All the properties investigated are affected by the cation's central atom nature, with ammonium-based ionic liquids presenting higher densities, viscosities, melting temperatures, and enthalpies. Activity coefficients at infinite dilution show the ammonium-based ionic liquids to present slightly higher infinite dilution activity coefficients for non-polar solvents, becoming slightly lower for polar solvents, suggesting that the ammonium-based ionic liquids present somewhat higher polarities. In good agreement these compounds present lower toxicities than the phosphonium congeners. To explain this behavior quantum chemical gas phase DFT calculations were performed on isolated ion pairs at the BP-TZVP level of theory. Electronic density results were used to derive electrostatic potentials of the identified minimum conformers. Electrostatic potential-derived CHelpG and Natural Population Analysis charges show the P atom of the tetraalkylphosphonium-based ionic liquids cation to be more positively charged than the N atom in the tetraalkylammonium-based analogous IL cation, and a noticeable charge delocalization occurring in the tetraalkylammonium cation, when compared with the respective phosphonium congener. It is argued that this charge delocalization is responsible for the enhanced polarity observed on the ammonium based ionic liquids explaining the changes in the thermophysical properties observed.

  11. Understanding the impact of the central atom on the ionic liquid behavior: Phosphonium vs ammonium cations

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Pedro J.; Ventura, Sónia P. M.; Batista, Marta L. S.; Schröder, Bernd; Coutinho, João A. P., E-mail: jcoutinho@ua.pt [CICECO, Departamento de Química, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Gonçalves, Fernando [Departamento de Biologia e CESAM (Centro de Estudos do Ambiente e do Mar), Universidade de Aveiro, 3810-193 Aveiro (Portugal); Esperança, José [Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, 2780-901 Oeiras (Portugal); Mutelet, Fabrice [Laboratoire Réactions et Génie des Procédés, CNRS (UPR3349), Nancy-Université, 1 rue Grandville, BP 20451 54001 Nancy (France)

    2014-02-14

    The influence of the cation's central atom in the behavior of pairs of ammonium- and phosphonium-based ionic liquids was investigated through the measurement of densities, viscosities, melting temperatures, activity coefficients at infinite dilution, refractive indices, and toxicity against Vibrio fischeri. All the properties investigated are affected by the cation's central atom nature, with ammonium-based ionic liquids presenting higher densities, viscosities, melting temperatures, and enthalpies. Activity coefficients at infinite dilution show the ammonium-based ionic liquids to present slightly higher infinite dilution activity coefficients for non-polar solvents, becoming slightly lower for polar solvents, suggesting that the ammonium-based ionic liquids present somewhat higher polarities. In good agreement these compounds present lower toxicities than the phosphonium congeners. To explain this behavior quantum chemical gas phase DFT calculations were performed on isolated ion pairs at the BP-TZVP level of theory. Electronic density results were used to derive electrostatic potentials of the identified minimum conformers. Electrostatic potential-derived CHelpG and Natural Population Analysis charges show the P atom of the tetraalkylphosphonium-based ionic liquids cation to be more positively charged than the N atom in the tetraalkylammonium-based analogous IL cation, and a noticeable charge delocalization occurring in the tetraalkylammonium cation, when compared with the respective phosphonium congener. It is argued that this charge delocalization is responsible for the enhanced polarity observed on the ammonium based ionic liquids explaining the changes in the thermophysical properties observed.

  12. Headspace single drop microextraction versus dispersive liquid-liquid microextraction using magnetic ionic liquid extraction solvents.

    Science.gov (United States)

    An, Jiwoo; Rahn, Kira L; Anderson, Jared L

    2017-05-15

    A headspace single drop microextraction (HS-SDME) method and a dispersive liquid-liquid microextraction (DLLME) method were developed using two tetrachloromanganate ([MnCl42-])-based magnetic ionic liquids (MIL) as extraction solvents for the determination of twelve aromatic compounds, including four polyaromatic hydrocarbons, by reversed phase high-performance liquid chromatography (HPLC). The analytical performance of the developed HS-SDME method was compared to the DLLME approach employing the same MILs. In the HS-SDME approach, the magnetic field generated by the magnet was exploited to suspend the MIL solvent from the tip of a rod magnet. The utilization of MILs in HS-SDME resulted in a highly stable microdroplet under elevated temperatures and long extraction times, overcoming a common challenge encountered in traditional SDME approaches of droplet instability. The low UV absorbance of the [MnCl42-]-based MILs permitted direct analysis of the analyte enriched extraction solvent by HPLC. In HS-SDME, the effects of ionic strength of the sample solution, temperature of the extraction system, extraction time, stir rate, and headspace volume on extraction efficiencies were examined. Coefficients of determination (R2) ranged from 0.994 to 0.999 and limits of detection (LODs) varied from 0.04 to 1.0μgL-1 with relative recoveries from lake water ranging from 70.2% to 109.6%. For the DLLME method, parameters including disperser solvent type and volume, ionic strength of the sample solution, mass of extraction solvent, and extraction time were studied and optimized. Coefficients of determination for the DLLME method varied from 0.997 to 0.999 with LODs ranging from 0.05 to 1.0μgL-1. Relative recoveries from lake water samples ranged from 68.7% to 104.5%. Overall, the DLLME approach permitted faster extraction times and higher enrichment factors for analytes with low vapor pressure whereas the HS-SDME approach exhibited better extraction efficiencies for analytes with

  13. Complex Permittivity of Ionic Liquid Mixtures Investigated by Terahertz Time-Domain Spectroscopy.

    Science.gov (United States)

    Mou, Sen; Rubano, Andrea; Paparo, Domenico

    2017-08-03

    Ionic liquids are salts found in their liquid state at ambient temperature. The physicochemical properties of ionic liquids can be tailored by selecting constituent cation and anion from numerous available ions. The physicochemical properties can be further tuned by mixing different neat ionic liquids. Reported data of ionic liquid mixtures reveal that frequently investigated properties such as density, viscosity, and thermal stability follow corresponding mixing laws. Complex permittivity in the interval of terahertz frequencies is of great importance to understand the molecular interactions and the solvation dynamics which drive the macroscopic properties of ionic liquids; however, to the best of our knowledge, there are few reports about the mixing behavior of complex permittivity in ionic liquid mixtures. In this contribution, binary mixtures of 1-butyl-3-methylimidazoulium iodide ([C4C1im]I) and 1-butyl-3- methylimidazoulium bis(trifluoromethylsulfonyl)imide ([C4C1im][NTf2]) are investigated in the terahertz spectral range, and the resulting low-energy spectra are analyzed in order to clarify the mixing laws at play. The results show that the complex permittivity of mixtures of [C4C1im]I and ([C4C1im][NTf2] obeys a linear mixing law.

  14. Influence of organic solvent on the separation of an ionic liquid from a lignin-ionic liquid mixture.

    Science.gov (United States)

    Weerachanchai, Piyarat; Lim, Kok Hwa; Lee, Jong-Min

    2014-03-01

    Sixteen solvents added in lignin-ionic liquid mixture provide four types of solubility characteristics. The distinct characteristics can be classified by considering solubility parameters including ET Scale, Kamlet-Taft parameters and solubility parameters. Group 1 solvent shows promising solvents for lignin-ionic liquid separation, contributing full dissolution of ionic liquid with lignin precipitation. Isopropanol, the most potential solvent has solubility properties as following normalized molar electronic transition energies (ET(N))=0.57, hydrogen-bond acidity (α)=0.76 and Hildebrand solubility parameter (δT)=23.58. This study examines potential solvents for ionic recovery, provides simple method of separation and leads to the feasibility of using ionic liquids in industrial applications. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Chelating ionic liquids for reversible zinc electrochemistry.

    Science.gov (United States)

    Kar, Mega; Winther-Jensen, Bjorn; Forsyth, Maria; MacFarlane, Douglas R

    2013-05-21

    Advanced, high energy-density, metal-air rechargeable batteries, such as zinc-air, are of intense international interest due to their important role in energy storage applications such as electric and hybrid vehicles, and to their ability to deal with the intermittency of renewable energy sources such as solar and wind. Ionic liquids offer a number of ideal thermal and physical properties as potential electrolytes in such large-scale energy storage applications. We describe here the synthesis and characterisation of a family of novel "chelating" ILs designed to chelate and solubilize the zinc ions to create electrolytes for this type of battery. These are based on quaternary alkoxy alkyl ammonium cations of varying oligo-ether side chains and anions such as p-toluene sulfonate, bis(trifluoromethylsulfonyl)amide and dicyanoamides. This work shows that increasing the ether chain length in the cation from two to four oxygens can increase the ionic conductivity and reduce the melting point from 67 °C to 15 °C for the tosylate system. Changing the anion also plays a significant role in the nature of the zinc deposition electrochemistry. We show that zinc can be reversibly deposited from [N(222(20201))][NTf2] and [N(222(202020201))][NTf2] beginning at -1.4 V and -1.7 V vs. SHE, respectively, but not in the case of tosylate based ILs. This indicates that the [NTf2] is a weaker coordinating anion with the zinc cation, compared to the tosylate anion, allowing the coordination of the ether chain to dominate the behavior of the deposition and stripping of zinc ions.

  16. Spectral SAR Ecotoxicology of Ionic Liquids: The Daphnia magna Case

    Directory of Open Access Journals (Sweden)

    Mihai V. Putz

    2007-01-01

    Full Text Available Aiming to provide a unified theory of ionic liquids ecotoxicity, the recent spectral structure activity relationship (S-SAR algorithm is employed for testing the two additive models of anionic-cationic interaction containing ionic liquid activity: the causal and the endpoint, |0+〉 and |1+〉 models, respectively. As a working system, the Daphnia magna ecotoxicity was characterized through the formulated and applied spectral chemical-ecobiological interaction principles. Specific anionic-cationic-ionic-liquid rules of interaction along the developed mechanistic hypersurface map of the main ecotoxicity paths together with the so-called resonance limitation of the standard statistical correlation analysis were revealed.

  17. Thermal boundary conductance of hydrophilic and hydrophobic ionic liquids

    Science.gov (United States)

    Oyake, Takafumi; Sakata, Masanori; Yada, Susumu; Shiomi, Junichiro

    2015-03-01

    A solid/liquid interface plays a critical role for understanding mechanisms of biological and physical science. Moreover, carrier density of the surface is dramatically enhanced by electric double layer with ionic liquid, salt in the liquid state. Here, we have measured the thermal boundary conductance (TBC) across an interface of gold thin film and ionic liquid by using time-domain thermoreflectance technique. Following the prior researches, we have identified the TBC of two interfaces. One is gold and hydrophilic ionic liquid, N,N-Diethyl-N-methyl-N-(2-methoxyethyl) ammonium tetrafluoroborate (DEME-BF4), which is a hydrophilic ionic liquid, and the other is N,N-Diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis (trifluoromethanesulfonyl) imide (DEME-TFSI), which is a hydrophobic ionic liquid. We found that the TBC between gold and DEME-TFIS (19 MWm-2K-1) is surprisingly lower than the interface between gold and DEME-BF4 (45 MWm-2K-1). With these data, the importance of the wetting angle and ion concentration for the thermal transport at the solid/ionic liquid interface is discussed. Part of this work is financially supported by Japan Society for the Promotion of Science (JSPS) and Japan Science and Technology Agency. The author is financially supported by JSPS Fellowship.

  18. Quantum state-resolved molecular scattering of NO (2Π1/2 at the gas-[Cnmim][Tf2N] room temperature ionic liquid interface: Dependence on alkyl chain length, collision energy, and temperature

    Directory of Open Access Journals (Sweden)

    Amelia Zutz

    2016-10-01

    Full Text Available Room temperature ionic liquids (RTILs represent a promising class of chemically tunable, low vapor pressure solvents with myriad kinetic applications that depend sensitively on the nature of gas-molecule interactions at the liquid surface. This paper reports on rovibronically inelastic dynamics at the gas-RTIL interface, colliding supersonically cooled hyperthermal molecular beams of NO (Π1/22, N = 0 from 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonylimide (or [Cnmim][Tf2N] and probing the scattered NO molecules via laser induced fluorescence (LIF from the A(2Σ state. Specifically, inelastic energy transfer into NO rovibrational and electronic degrees of freedom is explored as a function of RTIL alkyl chain length (n, incident collision energy (Einc and surface temperature (Ts. At low collision energies (Einc = 2.7(9 kcal/mol, the scattered NO molecules exhibit a rotational temperature (Trot systematically colder than Ts for all chain lengths, which signals the presence of non-equilibrium dynamics in the desorption channel. At high collision energies (Einc = 20(2 kcal/mol, microscopic branching into trapping/desorption (TD and impulsive scattering (IS pathways is clearly evident, with the TD fraction (α exhibiting a step-like increase between short (n = 2, 4 and long (n = 8, 12, 16 alkyl chains consistent with theoretical predictions. For all hydrocarbon chain lengths and RTIL temperature conditions, NO rotational excitation in the IS channel yields hyperthermal albeit Boltzmann-like distributions well described by a “temperature” (TIS = 900 -1200 K that decreases systematically with increasing n. Non-adiabatic, collision induced hopping between ground and excited spin-orbit states is found to be independent of RTIL alkyl chain length and yet increase with collision energy. The scattering data confirm previous experimental reports of an enhanced presence of the alkyl tail at the gas-RTIL interface with increasing n, as well as

  19. Highly efficient conductivity modulation of cinnamate-based light-responsive ionic liquids in aqueous solutions.

    Science.gov (United States)

    Yang, Jie; Wang, Huiyong; Wang, Jianji; Zhang, Yue; Guo, Zhongjia

    2014-12-11

    A new class of cinnamate-based light-responsive ionic liquids was synthesized and characterized, and these ionic liquids with longer alkyl chains showed a remarkable increase in ionic conductivity under UV light irradiation in aqueous solutions.

  20. Electrochemical behaviour of hydrogen in low-viscosity phosphonium ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Matsumiya, M. [Yokohama National Univ. (Japan). Graduate School of Environment and Information Sciences; Tsunashima, K. [Wakayama National College of Technology (Japan). Dept. of Materials Science; Kodama, S. [Nippon Chemical Industrial Co., Ltd., Tokyo (Japan)

    2011-10-15

    The electrochemical and diffusive properties of hydrogen in low-viscosity phosphonium ionic liquids were investigated by the electrochemical methods such as cyclic voltammetry and chronoamperometry. The hydrogen redox reactions were concluded to be a quasi-reversible system in phosphonium-based ionic liquids. The diffusion coefficients of hydrogen in these ionic liquids were of the order of 10{sup -10} m{sup 2} s{sup -1} at 25 C. Additionally, the obtained activation energy of the diffusion process for hydrogen was 11.2-15.9 kJ mol{sup -1} estimated from the temperature dependence of the diffusion coefficients. A new type of proton conducting medium such as triethylphosphonium bis(trifluoromethylsulfonyl)amide was synthesized by the neutralization reaction, because the trialkylphosphine-based ionic liquids with good stability at higher temperature and high conductivity were appropriate candidates. This proton conducting membrane containing the ionic liquids with trialkylphosphine-based cations and the polyvinylidenefluoride-co-hexafluoropropylene has been fabricated in the present study. The proton conducting membrane exhibits relatively high ionic conductivity along with good mechanical stability. (orig.)

  1. Simultaneous Design of Ionic Liquids and Azeotropic Separation Processes

    DEFF Research Database (Denmark)

    Roughton, Brock C.; White, John; Camarda, Kyle V.

    2011-01-01

    A methodology for the design of azeotrope separation processes using ionic liquids as entrainers is outlined. A Hildebrand solubility parameter group contribution model has been developed to screen for or design an ionic liquid entrainer that is soluble with the azeotropic components. Using the b...... % [BMPy][BF4] added. The driving force concept is used to design an extractive distillation process that minimizes energy inputs. The methodology given can be expanded to the use of ionic liquids as entrainers in any azeotropic system of interest.......A methodology for the design of azeotrope separation processes using ionic liquids as entrainers is outlined. A Hildebrand solubility parameter group contribution model has been developed to screen for or design an ionic liquid entrainer that is soluble with the azeotropic components. Using...... the best candidate, vapor-liquid equilibria data is predicted using a new ionic liquid UNIFAC model that has been developed. The UNIFAC model is used to confirm the breaking of the azeotrope. The methanol-acetone azeotrope at 1 atm is used as an example. The azeotrope was predicted to break with 10 mol...

  2. Ecotoxicological evaluation of magnetic ionic liquids.

    Science.gov (United States)

    Sintra, Tânia E; Nasirpour, Maryam; Siopa, Filipa; Rosatella, Andreia A; Gonçalves, Fernando; Coutinho, João A P; Afonso, Carlos A M; Ventura, Sónia P M

    2017-09-01

    Although magnetic ionic liquids (MILs) are not yet industrially applied, their continued development and eventual commercial use may lead to their appearance into the aquatic ecosystem through accidental spills or effluents, consequently promoting aquatic contaminations. Furthermore, the deficient information and uncertainty surrounding the environmental impact of MILs could be a major barrier to their widespread industrial application and international registration. Thus, in the present work, a range of cholinium salt derivatives with magnetic properties was synthesized and their ecotoxicity was evaluated towards the luminescent bacteria Vibrio fischeri. The results suggest that all MILs structures tested are moderately toxic, or even toxic, to the bacteria. Furthermore, their toxicity is highly dependent on the structural modifications of the cation, namely the alkyl side chain length and the number of hydroxyethyl groups, as well as the atomic number of the metal anion. Finally, from the magnetic anions evaluated, the [MnCl4](2-) is the less toxic. In order to improve the knowledge for the prospective design of environmentally safer MILs, it is important to expand this study to other aquatic organisms at different trophic levels. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Enhanced Mixed Feedstock Processing Using Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, Blake A [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

    2016-10-22

    Biomass pretreatment using certain ionic liquids (ILs) is very efficient, generally producing a substrate that is amenable to saccharification with fermentable sugar yields approaching theoretical limits. Although promising, several challenges must be addressed before IL pretreatment technology becomes commercially viable. Once of the most significant challenges is the affordable and scalable recovery and recycle or the IL itself. Pervaporation is a highly selective and scalable membrane separation process for quantitatively recovering volatile solutes or solvents directly from non-volatile solvents that could prove more versatile for IL dehydration than traditional solvent extraction processes, as well as efficient and energetically more advantageous than standard evaporative techniques. In this study we evaluated a commercially available pervaporation system for IL dehydration and recycling as part of an integrated IL pretreatment process using 1-ethyl-3-methylimidazolium acetate ([C2C1Im][OAc]) that has been proven to be very effective as a biomass pretreatment solvent. We demonstrate that >99.9 wt% [C2C1Im][OAc] can be recovered from aqueous solution and recycled at least five times. A preliminary techno-economic analysis validated the promising role of pervaporation in improving overall biorefinery process economics, especially in the case where other IL recovery technologies might lead to significant losses. These findings establish the foundation for further development of pervaporation as an effective method of recovering and recycling ILs using a commercially viable process technology.

  4. Permeation of Ionic Liquids through the skin

    Directory of Open Access Journals (Sweden)

    Ana Júlio

    2017-12-01

    Full Text Available Alternative forms of drug delivery such as delivery through the skin, have been developed to explore other routes. However, the incorporation of poorly soluble or partially insoluble drugs into these delivery systems represents a major problem. Ionic liquids (ILs may be incorporated in aqueous, oily or hydroalcoholic solutions and thus, may be used as excipients in drug delivery systems to increase/improve the topical and transdermal drug delivery. However, it is fundamental to consider the cytotoxicity of these salts and it is also crucial to evaluate if these compounds permeate through the skin. Herein, three imidazole-based ILs: [C2mim][Br], [C4mim][Br] and [C6mim][Br], were synthesized and each IL was incorporated within caffeine saturated solutions. Permeation studies of the active (caffeine in these solutions were performed to evaluate the amount of IL that permeated through the porcine ear skin in the presence of the active. To achieve this, gravimetric studies of the receptor compartment were performed. Results showed that the more lipophilic IL [C6mim][Br] presented the highest permeation through the skin. The permeation is dependent upon the size of the alkyl chain of the IL, and as more than 60% of the ILs permeate is it vital to consider the cytotoxicity of these salts when considering their incorporation in topical systems.

  5. Ionic Liquid-Based Optical and Electrochemical Carbon Dioxide Sensors

    Directory of Open Access Journals (Sweden)

    Kamalakanta Behera

    2015-12-01

    Full Text Available Due to their unusual physicochemical properties (e.g., high thermal stability, low volatility, high intrinsic conductivity, wide electrochemical windows and good solvating ability, ionic liquids have shown immense application potential in many research areas. Applications of ionic liquid in developing various sensors, especially for the sensing of biomolecules, such as nucleic acids, proteins and enzymes, gas sensing and sensing of various important ions, among other chemosensing platforms, are currently being explored by researchers worldwide. The use of ionic liquids for the detection of carbon dioxide (CO2 gas is currently a major topic of research due to the associated importance of this gas with daily human life. This review focuses on the application of ionic liquids in optical and electrochemical CO2 sensors. The design, mechanism, sensitivity and detection limit of each type of sensor are highlighted in this review.

  6. Dissolution of cellulose in ionic liquid: A review

    Science.gov (United States)

    Mohd, N.; Draman, S. F. S.; Salleh, M. S. N.; Yusof, N. B.

    2017-02-01

    Dissolution of cellulose with ionic liquids (IL) and deep eutectic solvent (DES) lets the comprehensive dissolution of cellulose. Basically, cellulose can be dissolved, in some hydrophilic ionic liquids, such as 1-butyl-3-methylimidazolium chloride (BMIMCl) and 1-allyl-3-methylimidazolium chloride (AMIMCl). Chloride based ionic liquids are suitable solvents for cellulose dissolution. Although the ILs is very useful in fine chemical industry, its application in the pharmaceutical and food industry have been very limited due to issues with toxicity, purity, and high cost. Seeing to these limitations, new green alternative solvent which is DES was used. This green solvents, may be definitely treated as the next-generation reagents for more sustainable industrial development. Thus, this review aims to discuss the dissolution of cellulose either with ionic liquids or DES and its application.

  7. Non-Toxic Ionic Liquid Fuels for Exploration Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC proposes to develop and test new, non-toxic ionic liquid fuels for propulsion applications. Vintage propulsion systems frequently use highly toxic...

  8. Production of biofuels and chemicals with ionic liquids

    CERN Document Server

    Fang, Zhen; Qi, Xinhua

    2013-01-01

    This book explores the application of ionic liquids to biomass for producing biofuels and chemicals. Covers pretreatment, fermentation, cellulose transformation, reaction kinetics and more, as well as subsequent production of biofuels and platform chemicals.

  9. Ionic Liquids – Development and Challenges in Industrial Application

    Directory of Open Access Journals (Sweden)

    Cvjetko Bubalo, M.

    2014-05-01

    Full Text Available Establishment of novel, highly productive, and sustainable processes for the production of industrially important compounds is becoming a growing area of research. Due to non-volatility, inflammability, great thermal, chemical and electrochemical stability and also recyclability, ionic liquids are extensively studied as possible green replacement for widely used conventional molecular solvents. Due to the extremely large number of possible chemical structures of ionic liquids, the ability to design ionic liquids for specific applications makes them unique solvents in electrochemistry, analytical chemistry, organic synthesis and (biocatalysis, separation processes, as well as functional fluids (lubricants, heat transfer fluids, corrosion inhibitors etc.. This paper presents a review of the scientific and technical literature related to ionic liquids, their basic properties, preparation and application, as well as the challenges of their application on an industrial scale.

  10. Ion field-evaporation from ionic liquids infusing carbon xerogel microtips

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Martinez, C. S., E-mail: carlita@mit.edu; Lozano, P. C. [Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2015-07-27

    Ionic liquid ion sources capable of producing positive and negative molecular ion beams from room-temperature molten salts have applications in diverse fields, from materials science to space propulsion. The electrostatic stressing of these ionic liquids places the liquid surfaces in a delicate balance that could yield unwanted droplet emission when not properly controlled. Micro-tip emitter configurations are required to guarantee that these sources will operate in a pure ionic regime with no additional droplets. Porous carbon based on resorcinol-formaldehyde xerogels is introduced as an emitter substrate. It is demonstrated that this material can be shaped to the required micron-sized geometry and has appropriate transport properties to favor pure ionic emission. Time-of-flight mass spectrometry is used to verify that charged particle beams contain solvated ions exclusively.

  11. Ion field-evaporation from ionic liquids infusing carbon xerogel microtips

    Science.gov (United States)

    Perez-Martinez, C. S.; Lozano, P. C.

    2015-07-01

    Ionic liquid ion sources capable of producing positive and negative molecular ion beams from room-temperature molten salts have applications in diverse fields, from materials science to space propulsion. The electrostatic stressing of these ionic liquids places the liquid surfaces in a delicate balance that could yield unwanted droplet emission when not properly controlled. Micro-tip emitter configurations are required to guarantee that these sources will operate in a pure ionic regime with no additional droplets. Porous carbon based on resorcinol-formaldehyde xerogels is introduced as an emitter substrate. It is demonstrated that this material can be shaped to the required micron-sized geometry and has appropriate transport properties to favor pure ionic emission. Time-of-flight mass spectrometry is used to verify that charged particle beams contain solvated ions exclusively.

  12. Membrane contactor assisted extraction/reaction process employing ionic liquids

    Science.gov (United States)

    Lin, Yupo J [Naperville, IL; Snyder, Seth W [Lincolnwood, IL

    2012-02-07

    The present invention relates to a functionalized membrane contactor extraction/reaction system and method for extracting target species from multi-phase solutions utilizing ionic liquids. One preferred embodiment of the invented method and system relates to an extraction/reaction system wherein the ionic liquid extraction solutions act as both extraction solutions and reaction mediums, and allow simultaneous separation/reactions not possible with prior art technology.

  13. The Colloidal Stability of Magnetic Nanoparticles in Ionic Liquids

    Science.gov (United States)

    2015-08-03

    NOTES 14. ABSTRACT During the reporting period the development of the ionic liquid ferrofluid (ILFF) based on EMIM-NTf2 was continued. The...nitrate (EAN) miscible ferrofluid based on the high-boiling-point solvent sulfolane. As part of this collaboration we have also been investigating new... ferrofluids based on other high-boiling solvents. 15. SUBJECT TERMS Electric Propulsion, Ionic liquids 16. SECURITY CLASSIFICATION

  14. Magnetic field tunable capacitive dielectric:ionic-liquid sandwich composites

    Science.gov (United States)

    Wu, Ye; Bhalla, Amar; Guo, Ruyan

    2016-03-01

    We examined the tunability of the capacitance for GaFeO3-ionic liquid-GaFeO3 composite material by external magnetic and electric field. Up to 1.6 folds of capacitance tunability could be achieved at 957 kHz with voltage 4 V and magnetic field 0.02 T applied. We show that the capacitance enhancement is due to the polarization coupling between dielectric layer and ionic liquid layer.

  15. The Twentieth International Symposium on Molten Salts and Ionic Liquids

    Science.gov (United States)

    2016-11-29

    Heterocyclic Carbene Involved?" by Hyung Kim "Carbon Dioxide Absorption Behavior and Cabronate Ion Transport of Lithium Orthosilicate/Molten Carbonate...Electrodeposition of Metals" by Remana Reddy "In Situ TEM Observations of Lithium Electrodeposition/Stripping Process in Ionic Liquid" by Tetsuya Tsuda "Green... America . iii Preface The 20th International Symposium on Molten Salts and Ionic Liquids Symposium was held on October 2 - 7, 2016, in Honolulu, Hawaii as

  16. Thermomorphic phase separation in ionic liquid-organic liquid systems - conductivity and spectroscopic characterization

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Berg, Rolf W.

    2005-01-01

    Electrical conductivity, FT-Raman and NMR measurements are demonstrated as useful tools to probe and determine phase behavior of thermomorphic ionic liquid-organic liquid systems. To illustrate the methods, consecutive conductivity measurements of a thermomorphic methoxyethoxyethyl-imidazolium io...... of the components in the system, the liquid-liquid equilibrium phase diagram of the binary mixture, and signify the importance of hydrogen bonding between the ionic liquid and the hydroxyl group of the alcohol....

  17. Study of Alginate-Supported Ionic Liquid and Pd Catalysts

    Directory of Open Access Journals (Sweden)

    Eric Guibal

    2012-01-01

    Full Text Available New catalytic materials, based on palladium immobilized in ionic liquid supported on alginate, were elaborated. Alginate was associated with gelatin for the immobilization of ionic liquids (ILs and the binding of palladium. These catalytic materials were designed in the form of highly porous monoliths (HPMs, in order to be used in a column reactor. The catalytic materials were tested for the hydrogenation of 4-nitroaniline (4-NA in the presence of formic acid as hydrogen donor. The different parameters for the elaboration of the catalytic materials were studied and their impact analyzed in terms of microstructures, palladium sorption properties and catalytic performances. The characteristics of the biopolymer (proportion of β-D-mannuronic acid (M and α-L-guluronic acid (G in the biopolymer defined by the M/G ratio, the concentration of the porogen agent, and the type of coagulating agent significantly influenced catalytic performances. The freezing temperature had a significant impact on structural properties, but hardly affected the catalytic rate. Cellulose fibers were incorporated as mechanical strengthener into the catalytic materials, and allowed to enhance mechanical properties and catalytic efficiency but required increasing the amount of hydrogen donor for catalysis.

  18. Desulfurization performance of azole-based ionic liquids

    Directory of Open Access Journals (Sweden)

    Liubei CHENG

    2017-10-01

    Full Text Available In order to study the addition of functional groups in ionic liquid anion and cation to achieve better absorbing of SO2, the 1,1,3,3-tetramethylguanidine triazole ( is synthesized using 1,1,3,3-tetramethylguanidine and triazole as raw materials. The desulfurization performance of the synthesized is systematically studied. The desulfurization performance and desulfurization mechanism of the are discussed. The results show that the has good performance of desulfurization and regeneration. At the atmospheric pressure, 1 mol of the absorbs 2.964 mol of SO2 at 20 ℃. With the increase of temperature, the desulfurization capacity of the decreases gradually. The molar absorption ratio increases with the increase of SO2 partial pressure, and under the conditions of 130 ℃, the desorption rate of the ionic liquid after saturated adsorption reaches over 95%. The mechanism investigation results show that the interaction of SO2 and is the combination of chemical absorption and physical absorption. The results have a certain reference value to improve the efficiency of flue gas treatment.

  19. Development of an Ionic-Liquid Absorption Heat Pump

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, Don

    2011-03-29

    Solar Fueled Products (SFP) is developing an innovative ionic-liquid absorption heat pump (ILAHP). The development of an ILAHP is extremely significant, as it could result in annual savings of more than 190 billion kW h of electrical energy and $19 billion. This absorption cooler uses about 75 percent less electricity than conventional cooling and heating units. The ILAHP also has significant environmental sustainability benefits, due to reduced CO2 emissions. Phase I established the feasibility and showed the economic viability of an ILAHP with these key accomplishments: • Used the breakthrough capabilities provided by ionic liquids which overcome the key difficulties of the common absorption coolers. • Showed that the theoretical thermodynamic performance of an ILAHP is similar to existing absorption-cooling systems. • Established that the half-effect absorption cycle reduces the peak generator temperature, improving collector efficiency and reducing collector area. • Component testing demonstrated that the most critical components, absorber and generator, operate well with conventional heat exchangers. • Showed the economic viability of an ILAHP. The significant energy savings, sustainability benefits, and economic viability are compelling reasons to continue the ILAHP development.

  20. Organocatalytic Imidazolium Ionic Liquids H/D Exchange Catalysts.

    Science.gov (United States)

    Zanatta, Marcileia; Dos Santos, Francisco P; Biehl, Cristina; Marin, Graciane; Ebeling, Gunter; Netz, Paulo A; Dupont, Jairton

    2017-03-03

    Simple 1,2,3-trialkylimidazolium cation associated with basic anions, such as hydrogen carbonate, prolinate, and imidazolate, is an active catalyst for the H/D exchange reaction of various substrates using CDCl3 as D source, without the addition of any extra bases or metal. High deuterium incorporation (up to 49%) in acidic C-H bonds of ketone and alkyne substrates (pKa from 18.7 to 28.8) was found at room temperature. The reaction proceeds through the fast and reversible deuteration of the 2-methyl H of the imidazolium cation followed by D transfer to the substrate. The IL acts as a neutral base catalyst in which the contact ion pair is maintained in the course of the reaction. The basic active site is due to the presence of a remote basic site in the anion namely, OH of bicarbonate, NH of prolinate, and activated water in the imidazolate anion. Detailed kinetic experiments demonstrate that the reaction is first order on the substrate and pseudozero order relative to the ionic liquid, due to the fast reversible reaction involving the deuteration of the ionic liquid by the solvent.

  1. IONIC LIQUIDS MATERIAL AS MODERN CONTEXT OF CHEMISTRY IN SCHOOL

    Directory of Open Access Journals (Sweden)

    Hernani Hernani

    2016-04-01

    Full Text Available One way to improve students’ chemistry literacy which is demanded in the modernization of modern technology-based chemistry learning is by studying ionic liquids. Low level of scientific literacy of students in Indonesia as revealed in the PISA in 2012 was the main reason of the research. Ionic liquids-based technology are necessary to be applied as a context for learning chemistry because: (1 the attention of the scientific an technology community in the use of ionic liquids as a new generation of green solvent, electrolyte material and fluidic engineering in recent years becomes larger, in line with the strong demands of the industry for the provision of new materials that are reliable, safe, and friendly for various purposes; (2 scientific explanations related to the context of the ionic liquid contains a lot of facts, concepts, principles, laws, models and theories can be used to reinforce the learning content as a media to develop thinking skill (process/competence as demanded by PISA; (3 The modern technology-based ionic liquid can also be used as a discourse to strengthen scientific attitude. The process of synthesis of ionic liquid involves fairly simple organic reagents, so it deserves to be included in the chemistry subject in school.

  2. Ionic Liquids as templating agents in formation of uranium-containing nanomaterials

    Science.gov (United States)

    Visser, Ann E; Bridges, Nicholas J

    2014-06-10

    A method for forming nanoparticles containing uranium oxide is described. The method includes combining a uranium-containing feedstock with an ionic liquid to form a mixture and holding the mixture at an elevated temperature for a period of time to form the product nanoparticles. The method can be carried out at low temperatures, for instance less than about 300.degree. C.

  3. Solubilizing and Stabilizing Proteins in Anhydrous Ionic Liquids through Formation of Protein-Polymer Surfactant Nanoconstructs.

    Science.gov (United States)

    Brogan, Alex P S; Hallett, Jason P

    2016-04-06

    Nonaqueous biocatalysis is rapidly becoming a desirable tool for chemical and fuel synthesis in both the laboratory and industry. Similarly, ionic liquids are increasingly popular anhydrous reaction media for a number of industrial processes. Consequently, the use of enzymes in ionic liquids as efficient, environment-friendly, commercial biocatalysts is highly attractive. However, issues surrounding the poor solubility and low stability of enzymes in truly anhydrous media remain a significant challenge. Here, we demonstrate for the first time that engineering the surface of a protein to yield protein-polymer surfactant nanoconstructs allows for dissolution of dry protein into dry ionic liquids. Using myoglobin as a model protein, we show that this method can deliver protein molecules with near native structure into both hydrophilic and hydrophobic anhydrous ionic liquids. Remarkably, using temperature-dependent synchrotron radiation circular dichroism spectroscopy to measure half-denaturation temperatures, our results show that protein stability increases by 55 °C in the ionic liquid as compared to aqueous solution, pushing the solution thermal denaturation beyond the boiling point of water. Therefore, the work presented herein could provide a platform for the realization of biocatalysis at high temperatures or in anhydrous solvent systems.

  4. Structure and dynamics of ionic liquids: Trimethylsilylpropyl-substituted cations and bis(sulfonyl)amide anions.

    Science.gov (United States)

    Wu, Boning; Yamashita, Yuki; Endo, Takatsugu; Takahashi, Kenji; Castner, Edward W

    2016-12-28

    Ionic liquids with cationic organosilicon groups have been shown to have a number of useful properties, including reduced viscosities relative to the homologous cations with hydrocarbon substituents on the cations. We report structural and dynamical properties of four ionic liquids having a trimethylsilylpropyl functional group, including 1-methyl-3-trimethylsilylpropylimidazolium (Si-C3-mim(+)) cation paired with three anions: bis(fluorosulfonyl)imide (FSI(-)), bis(trifluoromethanesulfonyl)imide (NTf2(-)), and bis(pentafluoroethanesulfonyl)imide (BETI(-)), as well as the analogous N-methyl-N-trimethylsilylpropylpyrrolidinium (Si-C3-pyrr(+)) cation paired with NTf2(-). This choice of ionic liquids permits us to systematically study how increasing the size and hydrophobicity of the anions affects the structural and transport properties of the liquid. Structure factors for the ionic liquids were measured using high energy X-ray diffraction and calculated from molecular dynamics simulations. The liquid structure factors reveal first sharp diffraction peaks (FSDPs) for each of the four ionic liquids studied. Interestingly, the domain size for Si-C3-mim(+)/NTf2(-) indicated by the maxima for these peaks is larger than for the more polar ionic liquid with a similar chain length, 1-pentamethyldisiloxymethyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide (SiOSi-mim(+)/NTf2(-)). For the series of Si-C3-mim(+) ionic liquids, as the size of the anion increases, the position of FSDP indicates that the intermediate range order domains decrease in size, contrary to expectation. Diffusivities for the anions and cations are compared for a series of both hydrocarbon-substituted and silicon-substituted cations. All of the anions show the same scaling with temperature, size, and viscosity, while the cations show two distinct trends-one for hydrocarbon-substituted cations and another for organosilicon-substituted cations, with the latter displaying increased friction.

  5. Modern ab initio valence bond theory calculations reveal charge shift bonding in protic ionic liquids.

    Science.gov (United States)

    Patil, Amol Baliram; Bhanage, Bhalchandra Mahadeo

    2016-06-21

    The nature of bonding interactions between the cation and the anion of an ionic liquid is at the heart of understanding ionic liquid properties. A particularly interesting case is a special class of ionic liquids known as protic ionic liquids. The extent of proton transfer in protic ionic liquids has been observed to vary according to the interacting species. Back proton transfer renders protic ionic liquids volatile and to be considered as inferior ionic liquids. We try to address this issue by employing modern ab initio valence bond theory calculations. The results indicate that the bonding in the cation and the anion of a prototypical ionic liquid, ethylammonium nitrate, is fundamentally different. It is neither characteristic of covalent/polar covalent bonding nor ionic bonding but rather charge shift bonding as a resonance hybrid of two competing ionic molecular electronic structure configurations. An investigation of other analogous protic ionic liquids reveals that this charge shift bonding seems to be a typical characteristic of protic ionic liquids while the ionic solid analogue compound ammonium nitrate has less charge shift bonding character as compared to protic ionic liquids. Further the extent of charge shift bonding character has been found to be congruent with the trends in many physicochemical properties such as melting point, conductivity, viscosity, and ionicity of the studied ionic liquids indicating that percentage charge shift character may serve as a key descriptor for large scale computational screening of ionic liquids with desired properties.

  6. Protic Cationic Oligomeric Ionic Liquids of the Urethane Type

    DEFF Research Database (Denmark)

    Shevchenko, V. V.; Stryutsky, A. V.; Klymenko, N. S.

    2014-01-01

    Protic oligomeric cationic ionic liquids of the oligo(ether urethane) type are synthesized via the reaction of an isocyanate prepolymer based on oligo(oxy ethylene)glycol with M = 1000 with hexamethylene-diisocyanate followed by blocking of the terminal isocyanate groups with the use of amine der...... orders of magnitude. The resulting compounds are thermally stable up to 200-270 degrees C....... derivatives of imidazole, pyridine, and 3-methylpyridine and neutralization of heterocycles with ethanesulfonic acid and p-toluenesulfonic acid. The structures and properties of the synthesized oligomeric ionic liquids substantially depend on the structures of the ionic groups. They are amorphous at room...

  7. Microstructures and dynamics of tetraalkylphosphonium chloride ionic liquids

    Science.gov (United States)

    Wang, Yong-Lei; Li, Bin; Sarman, Sten; Laaksonen, Aatto

    2017-12-01

    Atomistic simulations have been performed to investigate the effect of aliphatic chain length in tetraalkylphosphonium cations on liquid morphologies, microscopic ionic structures, and dynamical quantities of tetraalkylphosphonium chloride ionic liquids. The liquid morphologies are characterized by sponge-like interpenetrating polar and apolar networks in ionic liquids consisting of tetraalkylphosphonium cations with short aliphatic chains. The lengthening aliphatic chains in tetraalkylphosphonium cations lead to polar domains consisting of chloride anions and central polar groups in cations being partially or totally segregated in ionic liquid matrices due to a progressive expansion of apolar domains in between. Prominent polarity alternation peaks and adjacency correlation peaks are observed at low and high q range in total X-ray scattering structural functions, respectively, and their peak positions gradually shift to lower q values with lengthening aliphatic chains in tetraalkylphosphonium cations. The charge alternation peaks registered in the intermediate q range exhibit complicated tendencies due to a cancellation of peaks and anti-peaks in partial structural functions for ionic subcomponents. The particular microstructures and liquid morphologies in tetraalkylphosphonium chloride ionic liquids intrinsically contribute to distinct dynamics characterized by mean square displacements, van Hove correlation functions, and non-Gaussian parameters for ionic species in the heterogeneous ionic environment. Most tetraalkylphosphonium cations have higher translational mobilities than their partner anions due to strong coordination of chloride anions with central polar groups in tetraalkylphosphonium cations through strong Coulombic and hydrogen bonding interactions. The increase of aliphatic chain length in tetraalkylphosphonium cations leads to a concomitant shift of van Hove correlation functions and non-Gaussian parameters to larger radial distances and longer time

  8. Ionic structure in liquids confined by dielectric interfaces

    Science.gov (United States)

    Jing, Yufei; Jadhao, Vikram; Zwanikken, Jos W.; Olvera de la Cruz, Monica

    2015-11-01

    The behavior of ions in liquids confined between macromolecules determines the outcome of many nanoscale assembly processes in synthetic and biological materials such as colloidal dispersions, emulsions, hydrogels, DNA, cell membranes, and proteins. Theoretically, the macromolecule-liquid boundary is often modeled as a dielectric interface and an important quantity of interest is the ionic structure in a liquid confined between two such interfaces. The knowledge gleaned from the study of ionic structure in such models can be useful in several industrial applications, such as in the design of double-layer supercapacitors for energy storage and in the extraction of metal ions from wastewater. In this article, we compute the ionic structure in a model system of electrolyte confined by two planar dielectric interfaces using molecular dynamics simulations and liquid state theory. We explore the effects of high electrolyte concentrations, multivalent ions, dielectric contrasts, and external electric field on the ionic distributions. We observe the presence of non-monotonic ionic density profiles leading to a layered structure in the fluid which is attributed to the competition between electrostatic and steric (entropic) interactions. We find that thermal forces that arise from symmetry breaking at the interfaces can have a profound effect on the ionic structure and can oftentimes overwhelm the influence of the dielectric discontinuity. The combined effect of ionic correlations and inhomogeneous dielectric permittivity significantly changes the character of the effective interaction between the two interfaces.

  9. Synthesis, characterization and antiproliferative activity on cancer cell lines of new ionic liquids from ampicillin

    OpenAIRE

    Ferraz, Ricardo; Costa-Rodrigues, João; Fernandes,Maria Helena; Branco, Luís; Marrucho, Isabel; Ponte, Manuel Nunes; Prudêncio, Cristina; Noronha, João Paulo; Petrovski, Zeljko

    2011-01-01

    Ionic Liquids (ILs) are ionic compounds that possess melting temperature below 100ºC and they have been a topic of great interest since the mid-1990s due to their unique properties. The range of IL uses has been broadened, due to a significant increase in the variety of physical, chemical and biological ILs properties. They are now used as Active Pharmaceutical Ingredients (APIs) and recent interests are focused on their application as innovative solutions in new medical treatment and deliver...

  10. Electrochemical performance of potentiodynamically deposited polyaniline electrodes in ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Patil, Dipali S., E-mail: dipali.patilphy@gmail.com [Department of Physics, Yeungnam University, Gyeonbuk 712-749 (Korea, Republic of); Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004 (India); Pawar, S.A. [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004 (India); Department of Materials Science and Engineering, Chonnam National University, Gwangju 500 757 (Korea, Republic of); Patil, S.K.; Salavi, P.P.; Kolekar, S.S. [Department of Chemistry, Shivaji University, Kolhapur 416 004 (India); Devan, R.S.; Ma, Y.R. [Department of Physics, National Dong Hwa University, Hualien 97401, Taiwan (China); Kim, J.H. [Department of Materials Science and Engineering, Chonnam National University, Gwangju 500 757 (Korea, Republic of); Shin, J.C. [Department of Physics, Yeungnam University, Gyeonbuk 712-749 (Korea, Republic of); Patil, P.S., E-mail: patilps_2000@yahoo.com [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004 (India)

    2015-10-15

    Present work reports electropolymerization of aniline onto stainless steel substrate using room temperature ionic liquid N-methyl-2-pyrrolidonium hydrogensulfate [NMP][HSO{sub 4}] by potentiodynamic electrodeposition method. To study the effect of electropolymerization cycle number on the electrochemical performance, the number of scans is varied from 1{sup st} to 5{sup th} cycle. X-ray photoelectron spectroscopy is used for the phase identification of polyaniline (PANI) films. Scanning electrochemical microscopy (SECM) was used to study the electrochemical activity of PANI films. The highest specific capacitance of 581 Fg{sup −1} and energy density of 96.6 whkg{sup −1} are obtained for the sample, deposited using four cycle. - Graphical abstract: We have synthesized PANI samples with different thickness (or deposited mass) on stainless steel as a function of deposition cycles by potentiodynamic electrodeposition in room temperature IL [NMP][HSO{sub 4}]. A globular nanostructural growth of PANI is observed over the compact background of PANI for sample P{sub 2}. The sample P{sub 4} revealed a globular structure with spongy porous morphology. This nanostructure and porous structure is useful for supercapacitor, because it reduces the diffusion resistance of the electrolyte into electrode matrix. - Highlights: • Electropolymerization of aniline using room temperature ionic liquid N-methyl-2-pyrrolidonium hydrogensulfate [NMP][HSO4]. • The highest specific capacitance of 581 Fg{sup −1} and energy density of 96.60 Whkg{sup −1} is observed for the optimized sample. • The improved specific capacitance of PANI electrode material can be used to develop high performance supercapacitor.

  11. Method and apparatus using an active ionic liquid for algae biofuel harvest and extraction

    Science.gov (United States)

    Salvo, Roberto Di; Reich, Alton; Dykes, Jr., H. Waite H.; Teixeira, Rodrigo

    2012-11-06

    The invention relates to use of an active ionic liquid to dissolve algae cell walls. The ionic liquid is used to, in an energy efficient manner, dissolve and/or lyse an algae cell walls, which releases algae constituents used in the creation of energy, fuel, and/or cosmetic components. The ionic liquids include ionic salts having multiple charge centers, low, very low, and ultra low melting point ionic liquids, and combinations of ionic liquids. An algae treatment system is described, which processes wet algae in a lysing reactor, separates out algae constituent products, and optionally recovers the ionic liquid in an energy efficient manner.

  12. Chiral separation and determination of ofloxacin enantiomers by ionic liquid-assisted ligand-exchange chromatography.

    Science.gov (United States)

    Bi, Wentao; Tian, Minglei; Row, Kyung Ho

    2011-01-21

    A simple and accurate method for the separation and determination of ofloxacin enantiomers was developed by ionic liquid-assisted ligand-exchange high performance liquid chromatography. Both achiral and chiral ionic liquids were tested for their efficiency of ofloxacin enantiomeric separation. The effects of ligands, concentration of metal ion, organic modifier, pH of the mobile phase, and temperature were also investigated and evaluated. Optimal conditions were obtained on a conventional C(18) column, where the mobile phase consisted of methanol/water (20 : 80, v/v) (containing 4.0 mmol L(-1) amino acid ionic liquid and 3.0 mmol L(-1) copper sulfate) at a flow rate of 0.5 mL min(-1). Under this condition, the ofloxacin enantiomers could be baseline separated within 14 minutes; the proposed method was used to analyze different commercial ofloxacin medicines.

  13. Excess enthalpy, density, and heat capacity for binary systems of alkylimidazolium-based ionic liquids + water

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Miaja, Gonzalo; Troncoso, Jacobo [Departamento de Fisica Aplicada, Universidad de Vigo, Facultad de Ciencias, Campus As Lagoas, 32004 Ourense (Spain); Romani, Luis [Departamento de Fisica Aplicada, Universidad de Vigo, Facultad de Ciencias, Campus As Lagoas, 32004 Ourense (Spain)], E-mail: romani@uvigo.es

    2009-02-15

    Experimental measurements of excess molar enthalpy, density, and isobaric molar heat capacity are presented for a set of binary systems ionic liquid + water as a function of temperature at atmospheric pressure. The studied ionic liquids are 1-butyl-3-methylpyridinium tetrafluoroborate, 1-ethyl-3-methylimidazolium ethylsulfate, 1-butyl-3-methylimidazolium methylsulfate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate. Excess molar enthalpy was measured at 303.15 K whereas density and heat capacity were determined within the temperature range (293.15 to 318.15) K. From experimental data, excess molar volume and excess molar isobaric heat capacity were calculated. The analysis of the excess properties reveals important differences between the studied ionic liquids which can be ascribed to their capability to form hydrogen bonds with water molecules.

  14. Tuning the physicochemical properties of diverse phenolic ionic liquids for equimolar CO2 capture by the substituent on the anion.

    Science.gov (United States)

    Wang, Congmin; Luo, Huimin; Li, Haoran; Zhu, Xiang; Yu, Bo; Dai, Sheng

    2012-02-13

    Phenolic ionic liquids for the efficient and reversible capture of CO(2) were designed and prepared from phosphonium hydroxide and substituted phenols. The electron-withdrawing or electron-donating ability, position, and number of the substituents on the anion of these ionic liquids were correlated with the physicochemical properties of the ionic liquids. The results show that the stability, viscosity, and CO(2)-capturing ability of these ionic liquids were significantly affected by the substituents. Furthermore, the relationship between the decomposition temperature, the CO(2)-absorption capacity, and the basicity of these ionic liquids was quantitatively correlated and further rationalized by theoretical calculation. Indeed, these ionic liquids showed good stability, high absorption capacity, and low absorption enthalpy for CO(2) capture. This method, which tunes the physicochemical properties by making use of substituent effects in the anion of the ionic liquid, is important for the design of highly efficient and reversible methods for CO(2)-capture. This CO(2) capture process using diverse phenolic ionic liquids is a promising potential method for CO(2) absorption with both high absorption capacity and good reversibility. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Tuning the Physicochemical Properties of Diverse Phenolic Ionic Liquids for Equimolar CO2 Capture by the Substituent on the Anion

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Sheng [ORNL; Luo, Huimin [ORNL; Yu, Bo [ORNL; Li, Haoran [Zhejiang University; Wang, Congmin [ORNL

    2012-01-01

    Phenolic ionic liquids for the efficient and reversible capture of CO{sub 2} were designed and prepared from phosphonium hydroxide and substituted phenols. The electron-withdrawing or electron-donating ability, position, and number of the substituents on the anion of these ionic liquids were correlated with the physicochemical properties of the ionic liquids. The results show that the stability, viscosity, and CO{sub 2}-capturing ability of these ionic liquids were significantly affected by the substituents. Furthermore, the relationship between the decomposition temperature, the CO{sub 2}-absorption capacity, and the basicity of these ionic liquids was quantitatively correlated and further rationalized by theoretical calculation. Indeed, these ionic liquids showed good stability, high absorption capacity, and low absorption enthalpy for CO{sub 2} capture. This method, which tunes the physicochemical properties by making use of substituent effects in the anion of the ionic liquid, is important for the design of highly efficient and reversible methods for CO{sub 2}-capture. This CO{sub 2} capture process using diverse phenolic ionic liquids is a promising potential method for CO{sub 2} absorption with both high absorption capacity and good reversibility.

  16. Utilization of Ionic Liquids for the Separation of Organic Liquids from ...

    African Journals Online (AJOL)

    NICO

    components in the ionic liquid obtained by gas chromatography were used to determine the capability of [EMIM][EtSO4] and. [EMpy][EtSO4] as extracting ... Additional separation steps are required to purify the raffinate, extract and solvent ... ionic liquids were stored in a moisture-free environment such as desiccators and ...

  17. Nonlinear transport in ionic liquid gated strontium titanate nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Bretz-Sullivan, Terence M.; Goldman, A. M., E-mail: goldman@physics.umn.edu [School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2015-09-14

    Measurements of the current-voltage (I–V) characteristics of ionic liquid gated nanometer scale channels of strontium titanate have been carried out. At low gate voltages, the I–V characteristics exhibit a large voltage threshold for conduction and a nonlinear power law behavior at all temperatures measured. The source-drain current of these nanowires scales as a power law of the difference between the source-drain voltage and the threshold voltage. The scaling behavior of the I–V characteristic is reminiscent of collective electronic transport through an array of quantum dots. At large gate voltages, the narrow channel acts as a quasi-1D wire whose conductance follows Landauer's formula for multichannel transport.

  18. Absorption and oxidation of nitrogen oxide in ionic liquids

    DEFF Research Database (Denmark)

    Kunov-Kruse, Andreas Jonas; Thomassen, Peter Langelund; Riisager, Anders

    2016-01-01

    A new strategy for capturing nitrogen oxide, NO, from the gas phase is presented. Dilute NO gas is removed from the gas phase by ionic liquids under ambient conditions. The nitrate anion of the ionic liquid catalyzes the oxidation of NO to nitric acid by atmospheric oxygen in the presence of water...... investigations of the reaction and products are presented. The procedure reveals a new vision for removing the pollutant NO by absorption into a non-volatile liquid and converting it into a useful bulk chemical, that is, HNO3....

  19. Acidic ionic liquids for n-alkane isomerization in a liquid-liquid or slurry-phase reaction mode

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, C.; Hager, V.; Geburtig, D.; Kohr, C.; Wasserscheid, P. [Erlangen-Nuernberg Univ. (Germany). Lehrstuhl fuer Chemische Reaktionstechnik; Haumann, M. [Chemical Reaction Engineering, FAU Busan Campus, Korea (Korea, Republic of)

    2011-07-01

    Highly acidic ionic liquid (IL) catalysts offer the opportunity to convert n-alkanes at very low reaction temperatures. The results of IL catalyzed isomerization and cracking reactions of pure n-octane are presented. Influence of IL composition, [C{sub 4}C{sub 1}Im]Cl / AlCl{sub 3} / H{sub 2}SO{sub 4} and [C{sub 4}C{sub 1}Im]Cl / AlCl{sub 3} / 1-chlorooctane, on catalyst activity and selectivities to branched alkanes was investigated. Acidic chloroaluminate IL catalysts form liquid-liquid biphasic systems with unpolar organic product mixtures. Thus, recycling of the acidic IL is enabled by simple phase separation in the liquid-liquid biphasic reaction mode or the IL can be immobilized on an inorganic support with a large specific surface area. These supported ionic liquid phase (SILP) catalysts offer the advantage to get a macroscopically heterogeneous system while still preserving all benefits of the homogeneous catalyst which can be used for the slurry-phase n-alkane isomerization. The interaction of the solid support and acidic IL influences strongly the catalytic activity. (orig.)

  20. Application of ionic liquids based enzyme-assisted extraction of chlorogenic acid from Eucommia ulmoides leaves

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Tingting; Sui, Xiaoyu, E-mail: suixiaoyu@outlook.com; Li, Li; Zhang, Jie; Liang, Xin; Li, Wenjing; Zhang, Honglian; Fu, Shuang

    2016-01-15

    A new approach for ionic liquid based enzyme-assisted extraction (ILEAE) of chlorogenic acid (CGA) from Eucommia ulmoides is presented in which enzyme pretreatment was used in ionic liquids aqueous media to enhance extraction yield. For this purpose, the solubility of CGA and the activity of cellulase were investigated in eight 1-alkyl-3-methylimidazolium ionic liquids. Cellulase in 0.5 M [C6mim]Br aqueous solution was found to provide better performance in extraction. The factors of ILEAE procedures including extraction time, extraction phase pH, extraction temperatures and enzyme concentrations were investigated. Moreover, the novel developed approach offered advantages in term of yield and efficiency compared with other conventional extraction techniques. Scanning electronic microscopy of plant samples indicated that cellulase treated cell wall in ionic liquid solution was subjected to extract, which led to more efficient extraction by reducing mass transfer barrier. The proposed ILEAE method would develope a continuous process for enzyme-assisted extraction including enzyme incubation and solvent extraction process. In this research, we propose a novel view for enzyme-assisted extraction of plant active component, besides concentrating on enzyme facilitated cell wall degradation, focusing on improvement of bad permeability of ionic liquids solutions. - Highlights: • An ionic liquid based enzyme-assisted extraction method of natural product was explored. • ILEAE utilizes enzymatic treatment to improve permeability of ionic liquids solution. • Enzyme incubation and solvent extraction process were ongoing simultaneously. • ILEAE process simplified operating process and suitable for more complete extraction.

  1. On the solid, liquid and solution structural organization of imidazolium ionic liquids

    Directory of Open Access Journals (Sweden)

    Dupont Jairton

    2004-01-01

    Full Text Available 1,3-dialkyl imidazolium salts are one of the most popular and investigated classes of room temperature ionic liquids. Although in various cases the physical-chemical properties and/or the outcome of the processes in these liquids significantly differ from those performed in "classical" dipolar organic solvents, they are still regarded as merely homogeneous solvents. In this brief overview it is developed the concept that pure 1,3-dialkylimidazolium ionic liquids are better described as hydrogen-bonded polymeric supramolecules of the type {[(DAIx(Xx-n] n+ [(DAIx-n(Xx] n-}n where DAI is the 1,3-dialkylimidazolium cation and X the anion. This structural pattern is a general trend for the solid phase and is maintained to a great extent in the liquid phase and even in the gas phase. The introduction of other molecules and macromolecules occurs with a disruption of the hydrogen bond network and in some cases can generate nano-structures with polar and non-polar regions where inclusion-type compounds can be formed.

  2. Mapping the pharmaceutical design space by amorphous ionic liquid strategies.

    Science.gov (United States)

    Wiest, Johannes; Saedtler, Marco; Balk, Anja; Merget, Benjamin; Widmer, Toni; Bruhn, Heike; Raccuglia, Marc; Walid, Elbast; Picard, Franck; Stopper, Helga; Dekant, Wolfgang; Lühmann, Tessa; Sotriffer, Christoph; Galli, Bruno; Holzgrabe, Ulrike; Meinel, Lorenz

    2017-10-31

    Poor water solubility of drugs fuels complex formulations and jeopardizes patient access to medication. Simplifying these complexities we systematically synthesized a library of 36 sterically demanding counterions and mapped the pharmaceutical design space for amorphous ionic liquid strategies for Selurampanel, a poorly water soluble drug used against migraine. Patients would benefit from a rapid uptake after oral administration to alleviate migraine symptoms. Therefore, we probed the ionic liquids for the flux, supersaturation period and hygroscopicity leading to algorithms linking molecular counterion descriptors to predicted pharmaceutical outcome. By that, 30- or 800-fold improvements of the supersaturation period and fluxes were achieved as were immediate to sustained release profiles through structural counterions' optimization compared to the crystalline free acid of Selurampanel. Guided by ionic liquid structure, in vivo profiles ranged from rapid bioavailability and high maximal plasma concentrations to sustained patterns. In conclusion, the study outlined and predicted the accessible pharmaceutical design space of amorphous ionic liquid based and excipient-free formulations pointing to the enormous pharmaceutical potential of ionic liquid designs. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Unimolecular Solvolyses in Ionic Liquid: Alcohol Dual Solvent Systems

    Directory of Open Access Journals (Sweden)

    Elizabeth D. Kochly

    2016-01-01

    Full Text Available A study was undertaken of the solvolysis of pivaloyl triflate in a variety of ionic liquid:alcohol solvent mixtures. The solvolysis is a kΔ process (i.e., a process in which ionization occurs with rearrangement, and the resulting rearranged carbocation intermediate reacts with the alcohol cosolvent via two competing pathways: nucleophilic attack or elimination of a proton. Five different ionic liquids and three different alcohol cosolvents were investigated to give a total of fifteen dual solvent systems. 1H-NMR analysis was used to determine relative amounts of elimination and substitution products. It was found, not surprisingly, that increasing the bulkiness of alcohol cosolvent led to increased elimination product. The change in the amount of elimination product with increasing ionic liquid concentration, however, varied greatly between ionic liquids. These differences correlate strongly, though not completely, to the Kamlet–Taft solvatochromic parameters of the hydrogen bond donating and accepting ability of the solvent systems. An additional factor playing into these differences is the bulkiness of the ionic liquid anion.

  4. Novel developments in hydrogen storage, hydrogen activation and ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Doroodian, Amir

    2010-12-03

    This dissertation is divided into three chapters. Recently, metal-free hydrogen activation using phosphorous compounds has been reported in science magazine. We have investigated the interaction between hydrogen and phosphorous compounds in presence of strong Lewis acids (chapter one). A new generation of metal-free hydrogen activation, using amines and strong Lewis acids with sterically demanding nature, was already developed in our group. Shortage of high storage capacity using large substitution to improve sterical effect led us to explore the amine borane derivatives, which are explained in chapter two. Due to the high storage capacity of hydrogen in aminoborane derivatives, we have explored these materials to extend hydrogen release. These compounds store hydrogen as proton and hydride on adjacent atoms or ions. These investigations resulted in developing hydrogen storage based on ionic liquids containing methyl guanidinium cation. Then we have continued to develop ionic liquids based on methyl guanidinium cation with different anions, such as tetrafluoro borate (chapter three). We have replaced these anions with transition metal anions to investigate hydrogen bonding and catalytic activity of ionic liquids. This chapter illustrates the world of ionic liquid as a green solvent for organic, inorganic and catalytic reactions and combines the concept of catalysts and solvents based on ionic liquids. The catalytic activity is investigated particularly with respect to the interaction with CO{sub 2}. (orig.)

  5. Physicochemical properties and toxicities of hydrophobicpiperidinium and pyrrolidinium ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Salminen, Justin; Papaiconomou, Nicolas; Kumar, R. Anand; Lee,Jong-Min; Kerr, John; Newman, John; Prausnitz, John M.

    2007-06-25

    Some properties are reported for hydrophobic ionic liquids (IL) containing 1-methyl-1-propyl pyrrolidinium [MPPyrro]{sup +}, 1-methyl-1-butyl pyrrolidinium [MBPyrro]{sup +}, 1-methyl-1-propyl piperidinium [MPPip]{sup +}, 1-methyl-1-butyl piperidinium [MBPip]{sup +}, 1-methyl-1-octylpyrrolidinium [MOPyrro]{sup +} and 1-methyl-1-octylpiperidinium [MOPip]{sup +} cations. These liquids provide new alternatives to pyridinium and imidazolium ILs. High thermal stability of an ionic liquid increases safety in applications like rechargeable lithium-ion batteries and other electrochemical devices. Thermal properties, ionic conductivities, viscosities, and mutual solubilities with water are reported. In addition, toxicities of selected ionic liquids have been measured using a human cancer cell-line. The ILs studied here are sparingly soluble in water but hygroscopic. We show some structure-property relationships that may help to design green solvents for specific applications. While ionic liquids are claimed to be environmentally-benign solvents, as yet few data have been published to support these claims.

  6. Phase Behaviour of 1-Ethyl-3-methylimidazolium Thiocyanate Ionic Liquid with Catalytic Deactivated Compounds and Water at Several Temperatures: Experiments and Theoretical Predictions

    Directory of Open Access Journals (Sweden)

    Ramalingam Anantharaj

    2011-01-01

    Full Text Available Density, surface tension and refractive index were determined for the binary mixture of catalytic deactivated compounds with 1-ethyl-3-methylimidazolium thiocyanate {[EMIM][SCN]} at temperature of (298.15 to 323.15 K. For all the compounds with ILs, the densities varied linearly in the entire mole fraction with increasing temperature. From the obtained data, the excess molar volume and deviation of surface tension and refractive index have been calculated. A strong interaction was found between similar (cation-thiophene or cation-pyrrole compounds. The interaction of IL with dissimilar compounds such as indoline and quinoline and other multiple ring compounds was found to strongly depend on the composition of IL at any temperatures. For the mixtures, the surface tension decreases in the order of: thiophene > quinoline > pyridine > indoline > pyrrole > water. In general from the excess volume studies, the IL-sulphur/nitrogen mixture has stronger interaction as compared to IL-IL, thiophene-thiophene or pyrrole-pyrrole interaction. The deviation of surface tension was found to be inversely proportional to deviation of refractive index. The quantum chemical based COSMO-RS was used to predict the non-ideal liquid phase activity coefficient for all mixtures. It indicated an inverse relation between activity coefficient and excess molar volumes.

  7. Molecular Orbital Based Design Guidelines for Hypergolic Energetic Ionic Liquids

    Science.gov (United States)

    2015-01-01

    Paper from semi-empirical quantum calculations. Chambreau et al. [10] reported Fourier transform infrared experiments and ab initio calculations to... Fourier Transform In- frared Studies in Hypergolic Ignition of Ionic Liquids, J. Phys. Chem. A 2008, 112, 7816. [11] D. Sengupta, J. V. Cole, Quantum...D. McCrary, G. Chatel, S. A. Alaniz, O. A. Cojocaru, P. A. Beas- ley , L. A. Flores, S. P. Kelley, P. S. Barber, R. D. Rogers, Evaluating Ionic

  8. Electrolytes based on alkoxysilyl-functionalized ionic liquids: viscoelastic properties and conductivity.

    Science.gov (United States)

    Slemenik Perše, L; Colović, M; Hajzeri, M; Orel, B; Surca Vuk, A

    2014-08-14

    Ionic liquids can be successfully used as electrolytes in electrochemical devices when they are in their quasi-solid state. Among several methods of solidification, a sol-gel process was chosen and a set of alkoxysilyl-functionalized iodide imidazolium-based ionic liquids were synthesized. The electrolytes were prepared by mixing these ionic liquids with a non-polymerisable ionic liquid (1-methyl-3-propylimidazolium iodide (MPIm(+)I(-))). Iodine was dissolved in an electrolyte matrix in order to form an I3(-)/I(-) redox couple. The change of the structure from sol to gel was followed by rheological tests in order to show the effect of different rheological parameters on the gelation process. The solvolysis with glacial acetic acid and condensation were followed by rheological experiments on the samples taken from a batch, and in situ on the rheometer. The formed three-dimensional sol-gel networks of various alkoxysilyl-functionalized ionic liquids differed in their microstructures and viscoelastic properties that were correlated with conductivity. The results show that the conductivity of approximately 10(-3) S cm(-1) at room temperature was achieved for the gels with relatively high values of elastic modulus and noticeable viscous contribution. It is shown that not only the viscosity but also the viscoelastic behavior and especially the relationship between viscous and elastic moduli (phase shift) together with the time of gelation are essential for the high conductivity of electrolytes.

  9. Hydrolysis of Straw in Ionic Liquids with Acid as Catalyst under Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Yuanjing Zhang

    2015-01-01

    Full Text Available With ionic liquids as solvents and corn straw as raw material, different processes of lignocellulose pretreatment with acid as catalyst were studied under conventional heating/microwave irradiation and the reducing sugar was measured. The results indicated that acid can accelerate hydrolysis reaction of corn straw into reducing sugar with ionic liquids as solvent, and microwave irradiation was more efficient in pretreatment of corn straw than conventional heating. The influences of different acid catalysts, the concentration of acid, temperature, mass ratio of straw/[Bmim]Cl, and the amount of refill water were mainly tested, and the optimum experimental conditions are thus determined.

  10. Organosilica Membrane with Ionic Liquid Properties for Separation of Toluene/H2 Mixture

    Science.gov (United States)

    Maeda, Yohei; Yamamoto, Yusuke; Miyamoto, Manabu; Nishiyama, Norikazu

    2017-01-01

    In this study, we present a new concept in chemically stabilized ionic liquid membranes: an ionic liquid organosilica (ILOS) membrane, which is an organosilica membrane with ionic liquid-like properties. A silylated ionic liquid was used as a precursor for synthesis. The permselectivity, permeation mechanism, and stability of the membrane in the H2/toluene binary system were then compared with a supported ionic liquid membrane. The membrane showed a superior separation factor of toluene/H2 (>17,000) in a binary mixture system based on a solution–diffusion mechanism with improved durability over the supported ionic liquid membrane. PMID:28771202

  11. Stability and kinetic studies of supported ionic liquid phase catalysts for hydroformylation of propene

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Haumann, Marco

    2005-01-01

    Supported ionic liquid phase (SILP) catalysts have been studied with regard to their long-term stability in the continuous gas-phase hydroformylation of propene. Kinetic data have been acquired by variation of temperature, pressure, syngas composition, substrate concentration, and residence time...

  12. Rendering high charge density of states in ionic liquid-gated MoS 2 transistors

    NARCIS (Netherlands)

    Lee, Y.; Lee, J.; Kim, S.; Park, H.S.

    2014-01-01

    We investigated high charge density of states (DOS) in the bandgap of MoS2 nanosheets with variable temperature measurements on ionic liquid-gated MoS2 transistors. The thermally activated charge transport indicates that the electrical current in the two-dimensional MoS 2 nanosheets under high

  13. Spatially resolved electrochemistry in ionic liquids: surface structure effects on triiodide reduction at platinum electrodes

    NARCIS (Netherlands)

    Aaronson, Barak D.B.; Lai, Stanley; Unwin, Patrick R.

    2014-01-01

    Understanding the relationship between electrochemical activity and electrode structure is vital for improving the efficiency of dye-sensitized solar cells. Here, the reduction of triiodide to iodide in 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]) room temperature ionic liquid (RTIL)

  14. Process for carrying out a chemical reaction with ionic liquid and carbon dioxide under pressure

    NARCIS (Netherlands)

    Kroon, M.C.; Shariati, A.; Florusse, L.J.; Peters, C.J.; Van Spronsen, J.; Witkamp, G.J.; Sheldon, R.A.; Gutkowski, K.I.

    2006-01-01

    The invention is directed to a process for carrying out a chemical reaction in an ionic liquid as solvent and CO2 as cosolvent, in which process reactants are reacted in a homogeneous phase at selected pressure and temperature to generate a reaction product at least containing an end-product of the

  15. The Use of Supported Acidic Ionic Liquids in Organic Synthesis

    Directory of Open Access Journals (Sweden)

    Rita Skoda-Földes

    2014-06-01

    Full Text Available Catalysts obtained by the immobilisation of acidic ionic liquids (ILs on solid supports offer several advantages compared to the use of catalytically active ILs themselves. Immobilisation may result in an increase in the number of accessible active sites of the catalyst and a reduction of the amount of the IL required. The ionic liquid films on the carrier surfaces provide a homogeneous environment for catalytic reactions but the catalyst appears macroscopically as a dry solid, so it can simply be separated from the reaction mixture. As another advantage, it can easily be applied in a continuous fixed bed reactor. In the present review the main synthetic strategies towards the preparation of supported Lewis acidic and Brønsted acidic ILs are summarised. The most important characterisation methods and structural features of the supported ionic liquids are presented. Their efficiency in catalytic reactions is discussed with special emphasis on their recyclability.

  16. On the Synthesis of Molybdenum Nanoparticles under Reducing Conditions in Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Ayi A. Ayi

    2015-01-01

    Full Text Available We report on attempts to synthesize Mo nanoparticles under reducing conditions in ionic liquids (ILs. Ionic liquids were based on the 1-ethyl-3-methylimidazolium or 1-butyl-3-methylimidazolium (Emim and Bmim, resp. cations and the dicyanamide N(CN2, triflate (OTf, bis(trifluoromethylsulfonylimide-(NTf2, tetrafluoroborate (BF4, ethyl sulfate (ES, and methylsulfonate (MS anions. (NH46Mo7O24∗4H2O and NaBH4 were reacted in a set of imidazolium ionic liquids (ILs at 180°C to evaluate the potential of the ILs for stabilization of metallic Mo nanoparticles. XRD and TEM reveal a strong influence of the IL anion on the particle sizes, shapes, and crystal structures. The influence of the IL cation and the reaction temperature is much less pronounced.

  17. Atomistic Force Field for Pyridinium-Based Ionic Liquids: Reliable Transport Properties

    DEFF Research Database (Denmark)

    Voroshylova, I. V.; Chaban, V. V.

    2014-01-01

    Reliable force field (FF) is a central issue in successful prediction of physical chemical properties via computer simulations. This work introduces refined FF parameters for six popular ionic liquids (ILs) of the pyridinium family (butylpyridinium tetrafluoroborate, bis(trifluoromethanesulfonyl)......Reliable force field (FF) is a central issue in successful prediction of physical chemical properties via computer simulations. This work introduces refined FF parameters for six popular ionic liquids (ILs) of the pyridinium family (butylpyridinium tetrafluoroborate, bis...... and elevated temperature. The developed atomistic models provide a systematic refinement upon the well-known Canongia LopesPadua (CL&P) FF. Together with the original CL&P parameters the present models foster a computational investigation of ionic liquids....

  18. Novel hydrophobic ionic liquids electrolyte based on cyclic sulfonium used in dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Lei; Pan, Xu; Wang, Meng; Zhang, Changneng; Fang, Xiaqin; Chen, Shuanghong; Dai, Songyuan [Key Lab of Novel Thin Film Solar Cells, Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei, Anhui 230031 (China)

    2011-01-15

    A novel series of hydrophobic room temperature ionic liquids based on six cyclic sulfonium cations were first time synthesized and applied in dye-sensitized solar cells as pure solvents for electrolyte system. The chronoamperograms result showed that the length of substituent on sulfonium cations could inhibit the I{sub 3}{sup -} diffusion and the five-ring structure of sulfonium was benefit for fast triiodide ion diffusion. The electrochemical impendence spectra measurement of dye-sensitized solar cells with these ionic liquid electrolytes was carried out and the result indicated that the cations' structure had indeed influence on the cells' performance especially for the fill factor, which was further proved by the measurement result of I-V curves of these dye-sensitized solar cells. The conclusion was obtained that the electron exchange reaction on Pt counter electrode/electrolyte interface dominated the cells' performance for these ionic liquid electrolyte-based DSCs. (author)

  19. Tailoring The Conducting Polymers PPY And PANI With Ionic Liquid BMIMBr For Enhanced Electrochromic Properties

    Directory of Open Access Journals (Sweden)

    Barkat Ul-ain

    2017-06-01

    Full Text Available Conservation of energy is the biggest need of the hour for developing countries. Smart windows with electrochromic characteristics can be one of the solutions for power shortfall. In this study ionic liquid BMIMBr is successfully synthesized by the reflux method. Ionogels comprising of ionic liquid and polymers Polyaniline and Polypyrrol were electrochemically deposited by galvanostatic methods. These films are structurally characterized by XRD and SEM. Concentration of monomer and ionic liquid was changed in order to study the effect on electrochemical and electrochromic properties. The electrochromic character was analyzed by optical studies and colour change was evident at different potentials. To further investigate the electron transport properties electrical conductivity studies were carried out. In a nutshell different parameters are studied with respect to concentration and temperature so that best material could be obtained showing high optical contrast and stability. Taking these studies in account an effective electrochromic device can be fabricated.

  20. Extractive Deep Desulfurization of Liquid Fuels Using Lewis-Based Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Swapnil A. Dharaskar

    2013-01-01

    Full Text Available A new class of green solvents, known as ionic liquids (ILs, has recently been the subject of intensive research on the extractive desulfurization of liquid fuels because of the limitation of traditional hydrodesulfurization method. In present work, eleven Lewis acid ionic liquids were synthesized and employed as promising extractants for deep desulfurization of the liquid fuel containing dibenzothiophene (DBT to test the desulfurization efficiency. [Bmim]Cl/FeCl3 was the most promising ionic liquid and performed the best among studied ionic liquids under the same operating conditions. It can remove dibenzothiophene from the model liquid fuel in the single-stage extraction process with the maximum desulfurization efficiency of 75.6%. It was also found that [Bmim]Cl/FeCl3 may be reused without regeneration with considerable extraction efficiency of 47.3%. Huge saving on energy can be achieved if we make use of this ionic liquids behavior in process design, instead of regenerating ionic liquids after every time of extraction.

  1. Impact of gate geometry on ionic liquid gated ionotronic systems

    Directory of Open Access Journals (Sweden)

    A. T. Wong

    2017-04-01

    Full Text Available Ionic liquid electrolytes are gaining widespread application as a gate dielectric used to control ion transport in functional materials. This letter systematically examines the important influence that device geometry in standard “side gate” 3-terminal geometries plays in device performance of a well-known oxygen ion conductor. We show that the most influential component of device design is the ratio between the area of the gate electrode and the active channel, while the spacing between these components and their individual shapes has a negligible contribution. These findings provide much needed guidance in device design intended for ionotronic gating with ionic liquids.

  2. Impact of gate geometry on ionic liquid gated ionotronic systems

    Science.gov (United States)

    Wong, A. T.; Noh, J. H.; Pudasaini, P. R.; Wolf, B.; Balke, N.; Herklotz, A.; Sharma, Y.; Haglund, A. V.; Dai, S.; Mandrus, D.; Rack, P. D.; Ward, T. Z.

    2017-04-01

    Ionic liquid electrolytes are gaining widespread application as a gate dielectric used to control ion transport in functional materials. This letter systematically examines the important influence that device geometry in standard "side gate" 3-terminal geometries plays in device performance of a well-known oxygen ion conductor. We show that the most influential component of device design is the ratio between the area of the gate electrode and the active channel, while the spacing between these components and their individual shapes has a negligible contribution. These findings provide much needed guidance in device design intended for ionotronic gating with ionic liquids.

  3. Synthesis of novel ionic liquids from lignin-derived compounds

    Science.gov (United States)

    Socha, Aaron; Singh, Seema; Simmons, Blake A.; Bergeron, Maxime

    2017-09-19

    Methods and compositions are provided for synthesizing ionic liquids from lignin derived compounds comprising: contacting a starting material comprising lignin with a depolymerization agent to depolymerize the lignin and form a mixture of aldehyde containing compounds; contacting the mixture of aldehyde containing compounds with an amine under conditions suitable to convert the mixture of aldehyde containing compounds to a mixture of amine containing compounds; and contacting the mixture of amine containing compounds with an acid under conditions suitable to form an ammonium salt, thereby preparing the ionic liquid.

  4. Preparation of microfibers from wood/ionic liquid solutions.

    Science.gov (United States)

    Polaskova, Martina; Cermak, Roman; Verney, Vincent; Ponizil, Petr; Commereuc, Sophie; Gomes, Margarida F Costa; Padua, Agilio A H; Mokrejs, Pavel; Machovsky, Michal

    2013-01-30

    Two types of ionic liquids, 1-ethyl-3-methylimidazolim acetate and 1-ethyl-3-methylimidazolium lactate, were employed for the direct processing of pine wood into microfibers. The concentration of 5 wt.% of wood in ionic liquids was rated as the most appropriate for electrospinning. The fibers were electrospun into the collector water bath. The final structure varied from individual microfibers to fiber bundles. It was demonstrated that 1-ethyl-3-methylimidazolium lactate is a powerful solvent and provides the direct transformation of pristine pine wood into the non-wovens. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Physicochemical characterization of morpholinium cation based protic ionic liquids used as electrolytes.

    Science.gov (United States)

    Brigouleix, Catherine; Anouti, Mérièm; Jacquemin, Johan; Caillon-Caravanier, Magali; Galiano, Hervé; Lemordant, Daniel

    2010-02-11

    New protic ionic liquids (PILs) based on the morpholinium, N-methylmorpholinium, and N-ethyl morpholinium cations have been synthesized through a simple and atom-economic neutralization reaction between N-alkyl morpholine and formic acid. Their densities, refractive indices, thermal properties, and electrochemical windows have been measured. The temperature dependence of their dynamic viscosity and ionic conductivity have also been determined. The results allow us to classify them according to a classical Walden diagram and to evaluate their "fragility". In addition, morpholinium based PILs exhibit a large electrochemical window as compared to other protic ionic liquids (up 2.91 V) and possess relatively high ionic conductivities of 10-16.8 mS x cm(-1) at 25 degrees C and 21-29 mS x cm(-1) at 100 degrees C, and a residual conductivity close to 1.0 mS x cm(-1) at -15 degrees C. PIL-water mixtures exhibit high ionic conductivities up to 65 mS x cm(-1) at 25 degrees C and 120 mS x cm(-1) at 100 degrees C for morpholinium formate with water weight fraction w(w) = 0.6. Morpholinium based PILs studied in this work have a low cost and low toxicity, are good ionic liquids, and prove extremely fragile. They have wide applicable perspectives as electrolytes for fuel cell devices, thermal transfer fluids, and acid-catalyzed reaction media as replacements of conventional solvents.

  6. Novel types of ionic thermotropic liquid crystals

    Science.gov (United States)

    Bruce, Duncan W.; Dunmur, David A.; Lalinde, Elena; Maitlis, Peter M.; Styring, Peter

    1986-10-01

    Liquid crystals are usually categorized as either lyotropic mesophases in which fluid anisotropy results from polar headgroup packing of amphiphilic molecules, or as thermotropic mesophases where the orientational order arises from interactions between partially rigid anisotropic molecules. The phase types exhibited by lyotropic and thermotropic liquid crystals have distinctive structures, optical textures and physical properties. Inclusion of a rigid anisotropic moiety into a lyotropic liquid crystal gives an additional source of orientational ordering, and can lead to phase behaviour encompassing both thermotropic and lyotropic liquid crystals. We have prepared a series of silver-containing thermotropic liquid crystals based on the bis(stilbazole) silver (I) cation. Some members of this series, in association with the amphiphilic counter-ion lauryl sulphate, form liquid crystal mesophases characteristic of both lyotropic and thermotropic liquid crystals.

  7. Evaluation of ionic liquid epoxy carbon fiber composites in a cryogenic environment

    Science.gov (United States)

    Lyne, Christopher T.; Henry, Christopher R.; Kaukler, William F.; Grugel, R. N.

    2018-03-01

    A novel ionic liquid epoxy (ILE) was used to fabricate carbon fiber composite discs which were then subjected to biaxial strain testing in liquid nitrogen. The ILE composite showed a greater strain-to-failure at cryogenic temperatures when compared to a commercial epoxy. This result is likely an effect, as shown in micrographs, of the strong ILE bonding with the carbon fibers as well as it exhibiting plastic deformation at the fracture surface.

  8. Melting/freezing points of high concentrations of AlCl3 in a saturated chloroaluminate ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Mengqi [Univ. of Tennessee, Knoxville, TN (United States); Groves, Richard [Clean Energy Events, Wilmington, NC (United States); Counce, Robert M. [Univ. of Tennessee, Knoxville, TN (United States); Watson, Jack S. [Univ. of Tennessee, Knoxville, TN (United States); Zawodzinski, Thomas A. [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-11-20

    Melting/freezing points of AlCl3 in saturated chloroaluminate ionic liquids [molar ratio 2:1 AlCl3:1-ethyl-3-methyl imidazolium chloride (EMIC)] are measured by differential scanning calorimetry (DSC). A critical range of temperature data (50-130 °C) for AlCl3 dissolution and precipitation from saturated chloroaluminate ionic liquids is obtained. This range of temperature data is of significance to control phase transition of AlCl3 in saturated chloroaluminate ionic liquids. By applying the chloroaluminate ionic liquids to electrolytes for energy storage usage, solid AlCl3 can be partially dissolved and precipitated out during the charging/discharging cycle of energy storage equipment. Furthermore, the energy density of the electrolytes is expected to be greatly improved.

  9. Formation of Boundary Film from Ionic Liquids Enhanced by Additives

    Directory of Open Access Journals (Sweden)

    Erik Nyberg

    2017-04-01

    Full Text Available Room temperature ionic liquids (RTILs have several properties that make them interesting candidates as base fluids for extreme conditions. However, a lack of compatibility with tribo-improving additives combined with an often overly aggressive nature is limiting their use as base fluids. To overcome these drawbacks, hydrocarbon-imitating RTIL base fluids have recently been developed. In this study, the effects of several common additives in the novel RTIL (P-SiSO were examined by laboratory tribotesting. A reciprocating steel-steel ball-on-flat setup in an air atmosphere was used, where the lubricant performance was evaluated over a range of loads and temperatures. Surface analyses after testing were carried out using optical profilometry, scanning electron microscopy (SEM, and energy dispersive X-ray spectroscopy (EDS. Neat P-SiSO displayed high performance in the tribotests. At an elevated load and temperature, a shift in lubrication mode was observed with an accompanying increase in friction and wear. Surface analysis revealed a boundary film rich in Si and O in the primary lubrication mode, while P was detected after a shift to the secondary lubrication mode. An amine additive was effective in reducing wear and friction under harsh conditions. The amine was determined to increase formation of the protective Si–O film, presumably by enhancing the anion activity.

  10. Thermoresponsive ketoprofen-imprinted monolith prepared in ionic liquid.

    Science.gov (United States)

    Sun, Xuan; Zhao, Chun-Yan; Wang, Xian-Hua; Huang, Yan-Ping; Liu, Zhao-Sheng

    2014-09-01

    A thermoresponsive imprinted monolith with the ability of molecular recognition for ketoprofen was prepared for the first time. The smart monolith was synthesized in a stainless steel column using acrylamide (AAm) and 2-acrylamide-2-methyl propanesulfonic acid (AMPS) as functional monomers, which can form interpolymer complexation to restrict access of the analyte to the imprinted networks at low temperatures. To avoid a high back pressure of the column derived from neat dimethyl sulfoxide (DMSO) as a porogenic solvent that is needed to solve polar AMPS, an ionic liquid, [BMIM]BF4, was introduced into the pre-polymerization mixture. The molecular recognition ability towards ketoprofen of the resulting thermoresponsive molecularly imprinted polymer (MIP) monolith displayed significant dependence on temperature compared with a non-imprinted column (NIP), and the greatest imprinting factor was achieved at the transition temperature of 35 °C (above 10). Furthermore, the number of binding sites of the smart MIP monolith at 35 °C was about 76 times as large as that at 25 °C. In addition, Freundlich analyses indicated that the thermoresponsive MIP monolith had homogeneous affinity sites at both 25 and 35 °C with heterogeneity index 0.9251 and 0.9851, respectively.

  11. Toward an understanding of the salting-out effects in aqueous ionic liquid solutions: vapor-liquid equilibria, liquid-liquid equilibria, volumetric, compressibility, and conductivity behavior.

    Science.gov (United States)

    Sadeghi, Rahmat; Mostafa, Bahar; Parsi, Elham; Shahebrahimi, Yasaman

    2010-12-16

    The action of particular electrolytes in altering the solution properties of ionic liquids is well documented, although the origin of this effect is not clearly defined. In order to clarify this point, the aim of this work is to obtain further evidence about the salting-out effect produced by the addition of different salts to aqueous solutions of water miscible ionic liquids by evaluating the effect of a large series of salts on the vapor-liquid equilibria, liquid-liquid phase diagram, volumetric, compressibility, and conductometric properties of ionic liquids 1-alkyl-3-methylimidazolium halide ([C(n)mim][X]). In the first part of this work, the experimental measurements of water activity at 298.15 and 308.15 K for aqueous binary and ternary solutions containing 1-alkyl-3-methylimidazolium bromide ([Rmim][Br], R = butyl (C(4)), heptyl (C(7)), and octyl (C(8))), sodium dihydrogen citrate (NaH(2)Cit), disodium hydrogen citrate (Na(2)HCit), and trisodium citrate (Na(3)Cit) are taken using both vapor pressure osmometry (VPO) and improved isopiestic methods. The effect of temperature, charge on the anion of sodium citrate salts, and alkyl chain length of ionic liquids on the vapor-liquid equilibria properties of the investigated systems are studied. The constant water activity lines of all the ternary systems show large negative deviation from the linear isopiestic relation (Zdanovskii-Stokes-Robinson rule) derived using the semi-ideal hydration model, and the vapor pressure depression for a ternary solution is much larger than the sum of those for the corresponding binary solutions with the same molality of the ternary solution. The results have been interpreted in terms of the solute-water and solute-solute interactions. In the second part of this work, the effects of the addition of (NH(4))(3)Cit, K(3)Cit, Na(3)Cit, (NH(4))(2)HPO(4), and (NH(4))(3)PO(4) on the liquid-liquid phase diagram, apparent molar volume, isentropic compressibility, and conductivity of aqueous

  12. Phase equilibria and modeling of ammonium ionic liquid, C2NTf2, solutions.

    Science.gov (United States)

    Domańska, Urszula; Marciniak, Andrzej; Królikowski, Marek

    2008-01-31

    Novel quaternary ammonium ionic liquid, ethyl(2-hydroxyethyl)dimethylammonium bis(trifluomethylsulfonyl)imide (C2NTf2), has been prepared from N,N-dimethylethanolamine as a substrate. The paper includes a specific basic characterization of the synthesized compound by NMR and the basic thermophysical properties: the melting point, enthalpy of fusion, enthalpy of solid-solid phase transition, glass transition determined by the differential scanning calorimetry (DSC), temperature of decomposition, and water content. The density of the new compound was measured. The solid-liquid or liquid-liquid phase equilibria of binary mixtures containing {C2NTf2+water or an alcohol (propan-1-ol, butan-1-ol, hexan-1-ol, octan-1-ol, decan-1-ol), aromatic hydrocarbons (benzene, toluene), aliphatic hydrocarbons (n-hexane, n-octane), dimethylsulfoxide (DMSO), or tetrahydrofuran (THF)} have been measured by a dynamic method in a wide range of temperatures from 230 to 430 K. These data were correlated by means of the nonrandom two-liquid (NRTL) equation utilizing temperature-dependent parameters derived from the solid-liquid or liquid-liquid equilibrium. From the solubility results, the negative value of the partition coefficient of ionic liquid in binary system octan-1-ol/water (log P) at 298.15 K has been calculated.

  13. Solvent effects by ionic liquid-water mixtures on the heterogeneous hydrolysis of lignocellulosic biomass with solid catalysts

    Science.gov (United States)

    Prosser, Jacob H.

    Ionic liquids are novel solvents proposed as alternatives for the liquid phase catalysis of lignocellulosic biomass because these can molecularly dissolve lignocellulose to high concentrations. However, solvent effects caused by ionic liquids for this application, such as how they shift the kinetics and equilibrium of lignocellulose conversion relative to other solvents, as well as if these change the nature of catalysts used and inhibit catalytic activity or unfavorably alter catalytic selectivity have not been rigorously considered. Additionally, many issues associated with the use of ionic liquids as solvents in lignocellulose conversion arise. Firstly, most ionic liquids readily undergo liquid phase thermal degradation at moderately low temperatures relevant for catalysis. Secondly, solvothermal degradation of solid catalytic materials by ILs can occur and is something not widely evaluated. Furthermore, the catalytic nature of many commonly used catalysts is altered through ion exchange between ionizable surface groups and ionic liquid ions. To understand how hydrophilic imidazolium-based ionic liquids influence the hydrolysis of lignocellulose, I examine with the aid of spectroscopic ellipsometry, UV-Vis spectrophotometry, high performance liquid chromatography, reflectance-small angle x-ray scattering, and powder x-ray diffraction the: (1) thermal degradation of a 1,2,3-trialkylimidzaolium ionic liquid; (2) solvothermal stability of mesoporous silica and gamma-alumina catalytsts; (3) behavior of the hydrolysis reaction of a lignin model compound in 1,2,3-trialkylimidzaolium ionic liquid-water mixtures; and (4) this same reaction catalyzed by gamma-alumina. From my investigations, I discover that: (1) water is able to diminish the thermal degradation of imidazolium ionic liquids when its composition is above about 35 mol% in these mixtures, an effect I propose is from two different mechanisms; (2) mesoporous silica and gamma-alumina are solvothermally stable

  14. Synthesis and characterization of ionic liquid (EMImBF4)/Li+ - chitosan membranes for ion battery

    Science.gov (United States)

    Pasaribu, Marvin H.; Arcana, I. Made; Wahyuningrum, Deana

    2015-09-01

    Lithium ion battery has been currently developed and produced because it has a longer life time, high energycapacity, and the efficient use of lithium ion battery that is suitable for storing electrical energy. However, this battery has some drawbacks such as use liquid electrolytes that are prone to leakage and flammability during the battery charging process in high temperature. In this study, an ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) containing Li+ ions was synthesized and combined with chitosan polymer host as a polymer electrolyte membrane for lithium-ion batteries to solve this problems. This ionic liquid was obtained from the anion metathesis reaction between EMImBr and LiBF4 salt, while EMImBr was synthesized from the reaction between 1-methylimidazole and ethyl bromide utilizing Microwave Assisted Organic Synthesis (MAOS) method. The ionic liquid obtained was characterized by microstructure analysis with using NMR and FTIR spectroscopy. The polymer electrolyte membrane was characterized by analysis functional groups (FTIR), ionic conductivity (EIS), and surface morphology (SEM). The analysis results of ion conductivity by the EIS method showed the increase the ionic conductivity value of membranes from 1.30 × 10-2 S cm- 1 for chitosan to 1.30 × 10-2 S cm-1 for chitosan with EMImBF4/Li+, and this result was supported by analysis the surface morphology (SEM).

  15. Benzene solubility in ionic liquids: working toward an understanding of liquid clathrate formation.

    Science.gov (United States)

    Pereira, Jorge F B; Flores, Luis A; Wang, Hui; Rogers, Robin D

    2014-11-17

    The solubility of benzene in 15 imidazolium, pyrrolidinium, pyridinium, and piperidinium ionic liquids has been determined; the resulting, benzene-saturated ionic liquid solutions, also known as liquid clathrates, were examined with (1) H and (19) F nuclear magnetic resonance spectroscopy to try and understand the molecular interactions that control liquid clathrate formation. The results suggest that benzene interacts primarily with the cation of the ionic liquid, and that liquid clathrate formation (and benzene solubility) is controlled by the strength of the cation-anion interactions, that is, the stronger the cation-anion interaction, the lower the benzene solubility. Other factors that were determined to be important in the final amount of benzene in any given liquid clathrate phase included attractive interactions between the anion and benzene (when significant), and larger steric or free volume demands of the ions, both of which lead to greater benzene solubility. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Acidic Brønsted Ionic Liquids Catalyzed the Preparation of 1 ...

    African Journals Online (AJOL)

    naphthalen-2-ol derivatives. The inexpensive and non-toxic ionic liquids can be reused several times without noticeable loss of their activities. KEYWORDS Aldehyde, 2-aminobenzothiazole, β-naphthol, ionic liquids, catalyst, green chemistry.

  17. Recent Developments in Chemical Synthesis with Biocatalysts in Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Mahesh K. Potdar

    2015-09-01

    Full Text Available Over the past decade, a variety of ionic liquids have emerged as greener solvents for use in the chemical manufacturing industries. Their unique properties have attracted the interest of chemists worldwide to employ them as replacement for conventional solvents in a diverse range of chemical transformations including biotransformations. Biocatalysts are often regarded as green catalysts compared to conventional chemical catalysts in organic synthesis owing to their properties of low toxicity, biodegradability, excellent selectivity and good catalytic performance under mild reaction conditions. Similarly, a selected number of specific ionic liquids can be considered as greener solvents superior to organic solvents owing to their negligible vapor pressure, low flammability, low toxicity and ability to dissolve a wide range of organic and biological substances, including proteins. A combination of biocatalysts and ionic liquids thus appears to be a logical and promising opportunity for industrial use as an alternative to conventional organic chemistry processes employing organic solvents. This article provides an overview of recent developments in this field with special emphasis on the application of more sustainable enzyme-catalyzed reactions and separation processes employing ionic liquids, driven by advances in fundamental knowledge, process optimization and industrial deployment.

  18. Ionic liquid modified carbon paste electrode and investigation of its ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 37; Issue 3 ... Biosensor; ionic liquid; 1-methyl-3-butylimidazolium bromide; carbon paste electrode; horseradish peroxidase. ... Carbon paste bio-sensor has been constructed by entrapping horseradish peroxidase in graphite and IL mixed with paraffin oil as a binder.

  19. IONIC LIQUID-CATALYZED ALKYLATION OF ISOBUTANE WITH 2-BUTENE

    Science.gov (United States)

    A detailed study of the alkylation of isobutane with 2-butene in ionic liquid media has been conducted using 1-alkyl-3-methylimidazolium halides?aluminum chloride encompassing various alkyl groups (butyl-, hexyl-, and octyl-) and halides (Cl, Br, and I) on its cations and anions,...

  20. Green oxidation of alkenes in ionic liquid solvent by hydrogen ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 126; Issue 3. Green oxidation of alkenes in ionic liquid solvent by hydrogen peroxide over high performance Fe(III) Schiff base complexes immobilized on MCM-41. Mohammad Taghi Goldani Ali Mohammadi Reza Sandaroos. Regular Articles Volume 126 Issue 3 May ...

  1. Lunar Oxygen Production and Metals Extraction Using Ionic Liquids

    Science.gov (United States)

    Marone, Matthew; Paley, Mark Steven; Donovan, David N.; Karr, Laurel J.

    2009-01-01

    Initial results indicate that ionic liquids are promising media for the extraction of oxygen from lunar regolith. IL acid systems can solubilize regolith and produce water with high efficiency. IL electrolytes are effective for water electrolysis, and the spent IL acid media are capable of regeneration.

  2. High performance batteries with carbon nanomaterials and ionic liquids

    Science.gov (United States)

    Lu, Wen [Littleton, CO

    2012-08-07

    The present invention is directed to lithium-ion batteries in general and more particularly to lithium-ion batteries based on aligned graphene ribbon anodes, V.sub.2O.sub.5 graphene ribbon composite cathodes, and ionic liquid electrolytes. The lithium-ion batteries have excellent performance metrics of cell voltages, energy densities, and power densities.

  3. High performance ultracapacitors with carbon nanomaterials and ionic liquids

    Science.gov (United States)

    Lu, Wen; Henry, Kent Douglas

    2012-10-09

    The present invention is directed to the use of carbon nanotubes and/or electrolyte structures in various electrochemical devices, such as ultracapacitors having an ionic liquid electrolyte. The carbon nanotubes are preferably aligned carbon nanotubes. Compared to randomly entangled carbon nanotubes, aligned carbon nanotubes can have better defined pore structures and higher specific surface areas.

  4. Thermoelectric Power in Bilayer Graphene Device with Ionic Liquid Gating.

    Science.gov (United States)

    Chien, Yung-Yu; Yuan, Hongtao; Wang, Chang-Ran; Lee, Wei-Li

    2016-02-08

    The quest for materials showing large thermoelectric power has long been one of the important subjects in material science and technology. Such materials have great potential for thermoelectric cooling and also high figure of merit ZT thermoelectric applications. We have fabricated bilayer graphene devices with ionic-liquid gating in order to tune its band gap via application of a perpendicular electric field on a bilayer graphene. By keeping the Fermi level at charge neutral point during the cool-down, we found that the charge puddles effect can be greatly reduced and thus largely improve the transport properties at low T in graphene-based devices using ionic liquid gating. At (Vig, Vbg) = (-1 V, +23 V), a band gap of about 36.6 ± 3 meV forms, and a nearly 40% enhancement of thermoelectric power at T = 120 K is clearly observed. Our works demonstrate the feasibility of band gap tuning in a bilayer graphene using ionic liquid gating. We also remark on the significant influence of the charge puddles effect in ionic-liquid-based devices.

  5. DABCO CONTAINING ACIDIC POLY(IONIC LIQUID): AN EFFICIENT ...

    African Journals Online (AJOL)

    ABSTRACT. 1,4-Diazabicyclo[2.2.2]octane (DABCO) containing acidic poly(ionic liquid) (DAIL) has been prepared via condensation of 1,4-dichloro butane and DABCO, as an efficient acidic catalyst and has been applied in the one-pot preparation of 2,3-dihydroquinazolin-4(1H)-one derivatives. This catalyst has been ...

  6. Method for synthesis of titanium dioxide nanotubes using ionic liquids

    Science.gov (United States)

    Qu, Jun; Luo, Huimin; Dai, Sheng

    2013-11-19

    The invention is directed to a method for producing titanium dioxide nanotubes, the method comprising anodizing titanium metal in contact with an electrolytic medium containing an ionic liquid. The invention is also directed to the resulting titanium dioxide nanotubes, as well as devices incorporating the nanotubes, such as photovoltaic devices, hydrogen generation devices, and hydrogen detection devices.

  7. Ionic Liquid Electrolytes for Flexible Dye-Sensitized Solar Cells

    Science.gov (United States)

    2014-09-01

    Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite...Gorlov, M. Ionic Liquid Electrolyte for Dye-Sensitized Solar Cells. RSC DaltonTrans. 2008, 20, 2655–2666. 7. Zakeeruddin, S. M.; Wang, P.; Humphry

  8. Ionic liquid-facilitated preparation of lignocellulosic composites

    Science.gov (United States)

    Lignocellulosic composites (LCs) were prepared by partially dissolving cotton along with steam exploded Aspen wood and burlap fabric reinforcements utilizing an ionic liquid (IL) solvent. Two methods of preparation were employed. In the first method, a controlled amount of IL was added to preassembl...

  9. Ionic liquid modified carbon paste electrode and investigation of its ...

    Indian Academy of Sciences (India)

    Administrator

    mixed using pestle and mortar with the required amount of graphite. This ionic liquid modified carbon paste was tightly packed into a cavity (3⋅3 mm diameter) of a glass tube and the electrical contact was established via copper wire. Then 2 mg of horseradish peroxidase was added and the paste was mixed for 10 min.

  10. Brønsted acidity of protic ionic liquids: a modern ab initio valence bond theory perspective.

    Science.gov (United States)

    Patil, Amol Baliram; Mahadeo Bhanage, Bhalchandra

    2016-09-21

    Room temperature ionic liquids (ILs), especially protic ionic liquids (PILs), are used in many areas of the chemical sciences. Ionicity, the extent of proton transfer, is a key parameter which determines many physicochemical properties and in turn the suitability of PILs for various applications. The spectrum of computational chemistry techniques applied to investigate ionic liquids includes classical molecular dynamics, Monte Carlo simulations, ab initio molecular dynamics, Density Functional Theory (DFT), CCSD(t) etc. At the other end of the spectrum is another computational approach: modern ab initio Valence Bond Theory (VBT). VBT differs from molecular orbital theory based methods in the expression of the molecular wave function. The molecular wave function in the valence bond ansatz is expressed as a linear combination of valence bond structures. These structures include covalent and ionic structures explicitly. Modern ab initio valence bond theory calculations of representative primary and tertiary ammonium protic ionic liquids indicate that modern ab initio valence bond theory can be employed to assess the acidity and ionicity of protic ionic liquids a priori.

  11. Pysico-chemical properties of hydrophobic ionic liquids containing1-octylpyridinium, 1-octyl-2-methylpyridinium or1-octyl-4-methylpyridinium cations

    Energy Technology Data Exchange (ETDEWEB)

    Papaiconomou, Nicolas; Salminen, Justin; Lee, Jong-Min; Prausnitz, John M.

    2006-09-15

    This paper reports synthesis of some ionic liquids based on cations 1-octylpyridinium, 1-octyl-2-methylpyridinium or 1-octyl-4-methylpyridinium and anions dicyanamide [N(CN)2]-, bis(trifluoromethylsulfonyl)imide [Tf2N]-, bis(pentafluoroethylsulfonyl)imide [BETI]-, trifluoromethyl sulfonate [TfO]-, nonafluorobutyl sulfonate [NfO]-, tetrafluoroborate [BF4]-, trifluorophenylborate [BF3Ph]- or hexafluoroarsenate [AsF6]-. Melting points, decomposition temperatures, densities, mutual solubilities with water, and viscosities have been measured. Unlike similar ionic liquids containing imidazolium cations, pyridinium ionic liquids studied here are nearly immiscible in water. Viscosities are similar and water content is slightly lower than those for ionic liquids containing imidazolium cations.

  12. Paramagnetic ionic liquids for measurements of density using magnetic levitation.

    Science.gov (United States)

    Bwambok, David K; Thuo, Martin M; Atkinson, Manza B J; Mirica, Katherine A; Shapiro, Nathan D; Whitesides, George M

    2013-09-03

    Paramagnetic ionic liquids (PILs) provide new capabilities to measurements of density using magnetic levitation (MagLev). In a typical measurement, a diamagnetic object of unknown density is placed in a container containing a PIL. The container is placed between two magnets (typically NdFeB, oriented with like poles facing). The density of the diamagnetic object can be determined by measuring its position in the magnetic field along the vertical axis (levitation height, h), either as an absolute value or relative to internal standards of known density. For density measurements by MagLev, PILs have three advantages over solutions of paramagnetic salts in aqueous or organic solutions: (i) negligible vapor pressures; (ii) low melting points; (iii) high thermal stabilities. In addition, the densities, magnetic susceptibilities, glass transition temperatures, thermal decomposition temperatures, viscosities, and hydrophobicities of PILs can be tuned over broad ranges by choosing the cation-anion pair. The low melting points and high thermal stabilities of PILs provide large liquidus windows for density measurements. This paper demonstrates applications and advantages of PILs in density-based analyses using MagLev.

  13. Osmotic heat engine using thermally responsive ionic liquids

    KAUST Repository

    Zhong, Yujiang

    2017-07-11

    The osmotic heat engine (OHE) is a promising technology for converting low grade heat to electricity. Most of the existing studies have focused on thermolytic salt systems. Herein, for the first time, we proposed to use thermally responsive ionic liquids (TRIL) that have either an upper critical solution temperature (UCST) or lower critical solution temperature (LCST) type of phase behavior as novel thermolytic osmotic agents. Closed-loop TRIL-OHEs were designed based on these unique phase behaviors to convert low grade heat to work or electricity. Experimental studies using two UCST-type TRILs, protonated betaine bis(trifluoromethyl sulfonyl)imide ([Hbet][Tf2N]) and choline bis(trifluoromethylsulfonyl)imide ([Choline][Tf2N]) showed that (1) the specific energy of the TRIL-OHE system could reach as high as 4.0 times that of the seawater and river water system, (2) the power density measured from a commercial FO membrane reached up to 2.3 W/m2, and (3) the overall energy efficiency reached up to 2.6% or 18% of the Carnot efficiency at no heat recovery and up to 10.5% or 71% of the Carnet efficiency at 70% heat recovery. All of these results clearly demonstrated the great potential of using TRILs as novel osmotic agents to design high efficient OHEs for recovery of low grade thermal energy to work or electricity.

  14. Osmotic Heat Engine Using Thermally Responsive Ionic Liquids.

    Science.gov (United States)

    Zhong, Yujiang; Wang, Xinbo; Feng, Xiaoshuang; Telalovic, Selvedin; Gnanou, Yves; Huang, Kuo-Wei; Hu, Xiao; Lai, Zhiping

    2017-08-15

    The osmotic heat engine (OHE) is a promising technology for converting low grade heat to electricity. Most of the existing studies have focused on thermolytic salt systems. Herein, for the first time, we proposed to use thermally responsive ionic liquids (TRIL) that have either an upper critical solution temperature (UCST) or lower critical solution temperature (LCST) type of phase behavior as novel thermolytic osmotic agents. Closed-loop TRIL-OHEs were designed based on these unique phase behaviors to convert low grade heat to work or electricity. Experimental studies using two UCST-type TRILs, protonated betaine bis(trifluoromethyl sulfonyl)imide ([Hbet][Tf 2 N]) and choline bis(trifluoromethylsulfonyl)imide ([choline][Tf 2 N]) showed that (1) the specific energy of the TRIL-OHE system could reach as high as 4.0 times that of the seawater and river water system, (2) the power density measured from a commercial FO membrane reached up to 2.3 W/m 2 , and (3) the overall energy efficiency reached up to 2.6% or 18% of the Carnot efficiency at no heat recovery and up to 10.5% or 71% of the Carnet efficiency at 70% heat recovery. All of these results clearly demonstrated the great potential of using TRILs as novel osmotic agents to design high efficient OHEs for recovery of low grade thermal energy to work or electricity.

  15. Zinc Acetate Immobilized on Mesoporous Materials by Acetate Ionic Liquids as Catalysts for Vinyl Acetate Synthesis

    Directory of Open Access Journals (Sweden)

    Hang Xu

    2015-01-01

    Full Text Available Ionic liquid containing active ingredient Zn(CH3COO2 was loaded in mesoporous silica gel to form supported ionic liquids catalyst (SILC which was used to synthesize vinyl acetate monomer (VAM. SILC was characterized by 1HNMR, FT-IR, TGA, BET, and N2 adsorption/desorption and the acetylene method was used to evaluate SILC catalytic activity and stability in fixed reactor. The result shows that 1-allyl-3-acetic ether imidazole acetate ionic liquid is successfully fixed within mesoporous channel of silica gel. The average thickness of ionic liquid catalyst layer is about 1.05 nm. When the catalytic temperature is 195°C, the acetic acid (HAc conversion is 10.9% with 1.1 g vinyl acetate yield and 98% vinyl acetate (VAc selectivity. The HAc conversion is increased by rise of catalytic temperature and molar ratio of C2H2 : HAc and decreased by mass space velocity (WHSV. The catalyst activity is not significantly reduced within 7 days and VAc selectivity has a slight decrease.

  16. Determination of three physical properties of quinoline ionic liquids with hexafluorophosphate

    Directory of Open Access Journals (Sweden)

    Tang Dan

    2016-01-01

    Full Text Available Densities of one acidic ionic liquid (IL Quinolinum hexafluorophosphate ([HBpy][PF6], and four neutral dicationic ionic liquids (ILs based on quinoline and hexafluoro-phosphate and linked with poly(ethylene glycol (PEG: ([PEG200-DIL][PF6]2, [PEG400-DIL][PF6]2, [PEG800-DIL][PF6]2 and [PEG1000-DIL][PF6]2 were determined. In addition, the solubilities of six ILs in six lower alcohols, water, acetonitrile and diethyl ether were measured at 288.15 K; and the hydroscopicity of above five ILs were measured at the temperature of 298.15 K and relative humidity of 79% for 24 h. Densities of five ionic liquids were determined between 283.15 and 333.15 K. Then the densities of five binary system (ILs/acetonitrile were explored between 283.15 and 333.15 K, the type of the ionic liquid, the concentration of five ILs in CH3CN, and the effect of temperature on the binary systems, were correlated with the measured data.

  17. Self-lubricating, wear resistant protic ionic liquid-epoxy resin

    Directory of Open Access Journals (Sweden)

    M. D. Aviles

    2017-03-01

    Full Text Available A new self-lubricating, wear resistant epoxy resin material (ER+DCi has been obtained by addition of a 9 wt.% of the room-temperature protic ionic liquid (PIL tri-[bis(2-hydroxyethylammonium] citrate (DCi to the mixture of the prepolymer and the hardener composed of a mixture of amines. The highly polar tricationic protic ammonium carboxylate ionic liquid shows a high contact angle on the resin surface and distributes inside the epoxy matrix as spheres of around 50 µm in diameter, with a mean density of approximately 38 mm2. The presence of the ionic liquid fluid phase inside the cavities has been determined by SEM observation of fracture surfaces and FTIR microscopy. The DCi phase reduces the residual curing enthalpy and the glass transition temperature, as determined by DSC, without significantly changing microhardness or electrical resistivity values. DMA analysis shows that DCi reduces storage modulus, loss modulus and tan δ values. The tribological performance of the new material has been compared with that of the neat epoxy resin under pin-on-disc sliding conditions. ER+DCi shows more than 50% reduction of the friction coefficient with respect to neat epoxy resin, and no surface damage, in contrast with the severe wear that takes place in the case of neat epoxy resin. A self-lubrication mechanism by release of the ionic liquid lubricant under load is proposed.

  18. Raman spectroscopy, ab-initio model calculations, and conformational, equilibria in ionic liquids

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    2009-01-01

    that the structural resolving power of Raman spectroscopy will be appreciated by the reader, when used on crystals of known conformation and on the corresponding liquids, especially in combination with modern quantum mechanics calculations. It is hoped that these inetrdisciplinary methods will be applied to many more......A review of the recent developments in the study and understanding of room temperature ionic liquids are given. An intimate picture of how and why these liquids are not crystals at ambient conditions is attempted, based on evidence from crystallographical results combined with vibrational...... spectroscopy and ab-initio molecular orbital calculations. A discussion is given, based mainly on some recent FT- Raman spectroscopic results on the model ionic liquid system of 1-butyl-3-methyl-imidazolium ([C4C1Im]+X-) salts. The rotational isomerism of the [C4C1Im]+ cation is described: the presence of anti...

  19. First-Principles, Physically Motivated Force Field for the Ionic Liquid [BMIM][BF4].

    Science.gov (United States)

    Choi, Eunsong; McDaniel, Jesse G; Schmidt, J R; Yethiraj, Arun

    2014-08-07

    Molecular simulations play an important role in establishing structure-property relations in complex fluids such as room-temperature ionic liquids. Classical force fields are the starting point when large systems or long times are of interest. These force fields must be not only accurate but also transferable. In this work, we report a physically motivated force field for the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) based on symmetry-adapted perturbation theory. The predictions (from molecular dynamics simulations) of the liquid density, enthalpy of vaporization, diffusion coefficients, viscosity, and conductivity are in excellent agreement with experiment, with no adjustable parameters. The explicit energy decomposition inherent in the force field enables a quantitative analysis of the important physical interactions in these systems. We find that polarization is crucial and there is little evidence of charge transfer. We also argue that the often used procedure of scaling down charges in molecular simulations of ionic liquids is unphysical for [BMIM][BF4]. Because all intermolecular interactions in the force field are parametrized from first-principles, we anticipate good transferability to other ionic liquid systems and physical conditions.

  20. Catalytic Oxidation and Depolymerization of Lignin in Aqueous Ionic Liquid

    Directory of Open Access Journals (Sweden)

    Lalitendu Das

    2017-08-01

    Full Text Available Lignin is an integral part of the plant cell wall, which provides rigidity to plants, also contributes to the recalcitrance of the lignocellulosic biomass to biochemical and biological deconstruction. Lignin is a promising renewable feedstock for aromatic chemicals; however, an efficient and economic lignin depolymerization method needs to be developed to enable the conversion. In this study, we investigated the depolymerization of alkaline lignin in aqueous 1-ethyl-3-methylimidazolium acetate [C2C1Im][OAc] under oxidizing conditions. Seven different transition metal catalysts were screened in presence of H2O2 as oxidizing agent in a batch reactor. CoCl2 and Nb2O5 proved to be the most effective catalysts in degrading lignin to aromatic compounds. A central composite design was used to optimize the catalyst loading, H2O2 concentration, and temperature for product formation. Results show that lignin was depolymerized, and the major degradation products found in the extracted oil were guaiacol, syringol, vanillin, acetovanillone, and homovanillic acid. Lignin streams were characterized by Fourier transform infrared spectroscopy and gel permeation chromatography to determine effects of the experimental parameters on lignin depolymerization. The weight-average molecular weight (Mw of liquid stream lignin after oxidation, for CoCl2 and Nb2O5 catalysts were 1,202 and 1,520 g mol−1, respectively, lower than that of Kraft lignin. Polydispersity index of the liquid stream lignin increased as compared with Kraft lignin, indicating wide span of the molecular weight distribution as a result of lignin depolymerization. Results from this study provide insights into the role of oxidant and transition metal catalysts and the oxidative degradation reaction sequence of lignin toward product formation in presence of aqueous ionic liquid.

  1. Prediction of ignition delay of ADN-based ionic liquid propellants using thermal analysis

    OpenAIRE

    早田, 葵; 塩田, 謙人; 伊里, 友一朗; 松永, 浩貴; 羽生, 宏人; 三宅, 淳巳; Hayata, Mamoru; Shiota, Kento; Izato, Yuichiro; Matsunaga, Hiroki; Habu, Hiroto; Miyake, Atsumi

    2017-01-01

    Ammonium dinitramide based ionic liquid propellants have been studied as monopropellant in terms of high specific impulse, low melting point and low toxicity. The purpose of this study is construction prediction method of ignition delay and combustion temperature against heating rate of propellants for establishment of combustion control technique. The prediction method of ignition delay and combustion temperature is constructed by combination of thermal analysis method and combustion simulat...

  2. Synthesis and characterization of new ionic liquids; Sintese e caracterizacao de novos liquidos ionicos

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, L.M.C. de; Mattedi, S.; Boaventura, J.S., E-mail: luanaufrn@hotmail.co [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Escola Politecnica. Programa de Pos-Graduacao em Engenharia Quimica; Iglesias, M. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Escola Politecnica. Programa de Pos-Graduacao em Engenharia Quimica; Universidad de Santiago de Compostela (Spain). Escuela Tecnica Superior de Ingenieria. Dept. de Ingenieria Quimica

    2010-07-01

    In recent years, ionic liquids have been highlighted for its potential in various industrial applications. Among them, the salts of Broensted has a promising profile for the low toxicity, low cost and simple synthesis. This paper presents the synthesis and characterization of new salts of Bronsted with branched (lactate) or large chain anions (oleate) for future use as additives promoters of proton conductivity in fuel cells of ethanol. Experimental data were measured for density, sound velocity and conductivity of pure ionic liquids and mixtures. The density decreases linearly with increasing temperature, and sound velocity shows a similar trend, but not linear. The conductivity increases according to the Arrhenius model with activation energy less than 10 J/mol. Tests NMR, FTIR and TGA confirm ionic structure and thermal stability up to 165 deg C. (author)

  3. Multimodal porous carbon derived from ionic liquids: correlation between pore sizes and ionic clusters.

    Science.gov (United States)

    Jeong, Jun Hui; Lee, Je Seung; Roh, Kwang Chul; Kim, Kwang-Bum

    2017-10-05

    In this proof of concept study on the synthesis of ionic liquid (IL)-derived multimodal porous carbon using ionic clusters of different sizes as porogens, the carbonization behaviors of binary IL mixtures of 1-ethyl-3-methylimidazolium dicyanamide (EMIM-dca) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM-Tf 2 N) were systematically investigated to demonstrate the formation of multimodal porous carbons with hierarchical structures originating from the ionic cluster porogens. The multimodal porous structures of the resulting IL-derived porous carbons were characterized based on the quenched solid density functional theory, and the role of the ionic clusters as porogens is discussed. From the viewpoint of green and sustainable chemistry, the IL-based synthesis using ionic clusters as porogens is a simple, effective, and sustainable technique for synthesizing multimodal porous carbons with hierarchical structures. To the best of our knowledge, this is the first study demonstrating that a multimodal porous structure of IL-derived porous carbons could be systematically manipulated with the aid of ionic clusters of different sizes as porogens.

  4. Dysprosium electrodeposition from a hexaalkylguanidinium-based ionic liquid

    Science.gov (United States)

    Berger, Claudia A.; Arkhipova, Maria; Maas, Gerhard; Jacob, Timo

    2016-07-01

    The rare-earth element dysprosium (Dy) is an important additive that increases the magnetocrystalline anisotropy of neodymium magnets and additionally prevents from demagnetizing at high temperatures. Therefore, it is one of the most important elements for high-tech industries and is mainly used in permanent magnetic applications, for example in electric vehicles, industrial motors and direct-drive wind turbines. In an effort to develop a more efficient electrochemical technique for depositing Dy on Nd-magnets in contrast to commonly used costly physical vapor deposition, we investigated the electrochemical behavior of dysprosium(iii) trifluoromethanesulfonate in a custom-made guanidinium-based room-temperature ionic liquid (RTIL). We first examined the electrodeposition of Dy on an Au(111) model electrode. The investigation was carried out by means of cyclic voltammetry (CV) and X-ray photoelectron spectroscopy (XPS). The initial stages of metal deposition were followed by in situ scanning tunneling microscopy (STM). CV measurements revealed a large cathodic reduction peak, which corresponds to the growth of monoatomic high islands, based on STM images taken during the initial stages of deposition. XPS identified these deposited islands as dysprosium. A similar reduction peak was also observed on an Nd-Fe-B substrate, and positively identified as deposited Dy using XPS. Finally, we varied the concentration of the Dy precursor, electrolyte flow and temperature during Dy deposition and demonstrated that each of these parameters could be used to increase the thickness of the Dy deposit, suggesting that these parameters could be tuned simultaneously in a temperature-controlled flow cell to enhance the thickness of the Dy layer.The rare-earth element dysprosium (Dy) is an important additive that increases the magnetocrystalline anisotropy of neodymium magnets and additionally prevents from demagnetizing at high temperatures. Therefore, it is one of the most important

  5. Fabrication of a Multi-Walled Nanotube (MWNT Ionic Liquid Electrode and Its Application for Sensing Phenolics in Red Wines

    Directory of Open Access Journals (Sweden)

    Kyo-Il Kim

    2009-08-01

    Full Text Available A multi-walled nanotube (MWNT ionic liquid was prepared by the immobilization of 1-butylimidazole bromide onto an epoxy group on a poly(glycidyl methacrylate-grafted MWNT, which was synthesized by radiation-induced graft polymerization of glycidyl methacrylate onto MWNT in an aqueous solution. Subsequently, a MWNT ionic liquid electrode was fabricated by hand-casting MWNT ionic liquid, tyrosinase, and chitosan solution as a binder on indium tin oxide (ITO glass. The sensing ranges of the MWNT ionic liquid electrode with immobilized tyrosinase was in the range of 0.01-0.08 mM in a phosphate buffer solution. The optimal conditions such as pH, temperature, and effects of different phenolic compounds were determined. The total phenolic compounds of three commercial red wines were also determined on the tyrosinase-immobilized biosensor.

  6. Force microscopy of layering and friction in an ionic liquid.

    Science.gov (United States)

    Hoth, Judith; Hausen, Florian; Müser, Martin H; Bennewitz, Roland

    2014-07-16

    The mechanical properties of the ionic liquid 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl) trifluorophosphate ([Py1,4][FAP]) in confinement between a SiOx and a Au(1 1 1) surface are investigated by means of atomic force microscopy (AFM) under electrochemical control. Up to 12 layers of ion pairs can be detected through force measurements while approaching the tip of the AFM to the surface. The particular shape of the force versus distance curve is explained by a model for the interaction between tip, gold surface and ionic liquid, which assumes an exponentially decaying oscillatory force originating from bulk liquid density correlations. Jumps in the tip-sample distance upon approach correspond to jumps of the compliant force sensor between branches of the oscillatory force curve. Frictional force between the laterally moving tip and the surface is detected only after partial penetration of the last double layer between tip and surface.

  7. Salting-out in Aqueous Solutions of Ionic Liquids and K3PO4: Aqueous Biphasic Systems and Salt Precipitation

    OpenAIRE

    Najdanovic-Visak, Vesna; Canongia Lopes, Jos? N.; Visak, Zoran P.; Trindade, J.; Rebelo, Lu?s P. N.

    2007-01-01

    The salting-out effect produced by the addition of potassium phosphate, K3PO4 to aqueous solutions of water-miscible ionic liquids, viz. 1-ethyl-3-methylimidazolium ethyl sulfate, 1-butyl-3-methylimidazolium methyl sulfate, or 1-alkyl-3-methylimidazolium chloride ( alkyl = butyl, octyl or decyl) is investigated. The effects are analyzed using both the corresponding temperature-composition pseudo-binary and composition ternary phase diagrams. Different regions of liquid-liquid and solid-liquid...

  8. Thermally stable microemulsions comprising imidazolium based surface active ionic liquids, non-polar ionic liquid and ethylene glycol as polar phase.

    Science.gov (United States)

    Kaur, Manvir; Singh, Gurbir; Kumar, Sandeep; Navnidhi; Kang, Tejwant Singh

    2018-02-01

    Ionic liquid (IL), 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, [C2mim] [Tf2N], as a non-polar phase in conjunction with polar ethylene glycol (EG) forms microemulsions stabilized by surface active ionic liquids (SAILs), N-methyl-N-alkylimidazolium chlorides, [Cnmim] [Cl], where n = 8, 12 and 16 in conjunction with decanol as co-surfactant. The phase behaviour of the ternary systems has been investigated and three regions of microemulsions - polar-in-ionic liquid, bicontinuous and ionic liquid-in-polar, have been identified using electrical conductivity measurements. The effect of alkyl chain length on the phase behavior has been discussed in detail. The one-phase microemulsion region is found to decrease with the increase in the alkyl chain length of the SAILs. The microstructural characteristics have been investigated by using FTIR and NMR spectroscopy. The micropolarity of reverse micelles present in the microemulsions has been investigated using UV-Vis spectroscopy employing methyl orange as a polarity probe. The dynamics of solvent relaxation in microemulsions have been investigated by steady-state and time-resolved fluorescence spectroscopy using coumarin 153 (C-153) as fluorescence probe at different compositions of microemulsions. The dynamic light scattering measurements (DLS) reveals the expansion of reverse micelles formed by [Cnmim][Cl] in non polar [C2mim] [Tf2N] upon the addition of polar component. Interestingly, the microemulsions have been found to be thermally stable in a wide temperature range as revealed from temperature dependence UV-Vis, fluorescence and DLS measurements. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Activity coefficients at infinite dilution measurements for organic solutes and water in the ionic liquid 1-ethyl-3-methylimidazolium trifluoroacetate.

    Science.gov (United States)

    Domańska, Urszula; Marciniak, Andrzej

    2007-10-18

    The activity coefficients at infinite dilution, gamma13(infinity) for 29 solutes, alkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons, alcohols and water in the ionic liquid 1-ethyl-3-methylimidazolium trifluoroacetate ([EMIM][TFA]), were determined by gas-liquid chromatography at temperatures from 298.15-368.15 K. The partial molar excess enthalpies at infinite dilution DeltaH1(E,infinity) values were calculated from the experimental gamma13(infinity) values obtained over the temperature range. The selectivities for the hexane/benzene and cyclohexane/benzene separation were calculated from gamma13(infinity) and compared to the literature values for other ionic liquids, NMP and sulfolane.

  10. Excess enthalpies of mixing of piperidinium ionic liquids with short-chain alcohols: measurements and PC-SAFT modeling.

    Science.gov (United States)

    Paduszyński, Kamil; Królikowski, Marek; Domańska, Urszula

    2013-04-11

    This work is a continuation of our systematic study on thermodynamic properties of 1-n-alkyl-1-methylpiperdinium bis[(trifluoromethyl)sulfonyl]imides homologous series of ionic liquids ([CnC1Pip][NTf2]). Excess enthalpies of mixing (H(E)) of four binary systems containing two ionic liquids, namely [C4C1Pip][NTf2] and [C6C1Pip][NTf2], and two short-chain alcohols, namely ethanol and 1-propanol, were measured by isothermal titration calorimetry. Alcohol-to-ionic liquid and ionic liquid-to-alcohol titration experiments were carried out at temperature T = 298.15 K and atmospheric pressure. The experimental data were modeled in terms of perturbed-chain statistical associating fluid theory (PC-SAFT). Wolbach-Sandler combining rules were adopted in order to account for ionic liquid-alcohol cross-association. The model was applied in a conventional manner (i.e., without any binary corrections) as well as in a novel predictive mode developed previously by our group [Paduszyński, K.; Domańska, U. J. Phys. Chem. B 2012, 116, 5002-5018; Domańska et al. J. Phys. Chem. B 2012, 116, 8191-8200]. The latter approach employs temperature-dependent binary correction fitted to experimental limiting activity coefficient of alcohol in ionic liquid.

  11. Study of nanostructural organization of ionic liquids by electron paramagnetic resonance spectroscopy.

    Science.gov (United States)

    Merunka, Dalibor; Peric, Mirna; Peric, Miroslav

    2015-02-19

    The X-band electron paramagnetic resonance spectroscopy (EPR) of a stable, spherical nitroxide spin probe, perdeuterated 2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl (pDTO) has been used to study the nanostructural organization of a series of 1-alkyl-3-methylimidazolium tetrafluoroborate ionic liquids (ILs) with alkyl chain lengths from two to eight carbons. By employing nonlinear least-squares fitting of the EPR spectra, we have obtained values of the rotational correlation time and hyperfine coupling splitting of pDTO to high precision. The rotational correlation time of pDTO in ILs and squalane, a viscous alkane, can be fit very well to a power law functionality with a singular temperature, which often describes a number of physical quantities measured in supercooled liquids. The viscosity of the ILs and squalane, taken from the literature, can also be fit to the same power law expression, which means that the rotational correlation times and the ionic liquid viscosities have similar functional dependence on temperature. The apparent activation energy of both the rotational correlation time of pDTO and the viscous flow of ILs and squalane increases with decreasing temperature; in other words, they exhibit strong non-Arrhenius behavior. The rotational correlation time of pDTO as a function of η/T, where η is the shear viscosity and T is the temperature, is well described by the Stokes-Einstein-Debye (SED) law, while the hydrodynamic probe radii are solvent dependent and are smaller than the geometric radius of the probe. The temperature dependence of hyperfine coupling splitting is the same in all four ionic liquids. The value of the hyperfine coupling splitting starts decreasing with increasing alkyl chain length in the ionic liquids in which the number of carbons in the alkyl chain is greater than four. This decrease together with the decrease in the hydrodynamic radius of the probe indicates a possible existence of nonpolar nanodomains.

  12. Simultaneous Design of Ionic Liquids and Azeotropic Separation for Systems Containing Water

    DEFF Research Database (Denmark)

    Roughton, Brock; Camarda, Kyle V.; Gani, Rafiqul

    interaction parameters were fitted for the newly defined ionic liquid groups. The ionic liquid UNIFAC model was used to predict vapor-liquid equilibria for several aqueous azeotropic systems. The ionic liquids were evaluated for use as an entrainer for water in binary azeotropic mixtures where the mole....... Since a large number of azeotropes encountered include water as one of the compounds, the use of ionic liquids in solvent-based separation of water in azeotropic systems has been investigated. Along with the design of the ionic liquid being used to entrain water, the extractive distillation process has...... to check for consistency. The ionic liquid UNIFAC model was developed for a selected set of ionic liquid cations and anions. Group volume and area parameters were calculated using a three step procedure. First, the rules of Bondi were used for any applicable molecular groups within the cation or anion...

  13. Ionic liquid ultrasound assisted dispersive liquid-liquid microextraction method for preconcentration of trace amounts of rhodium prior to flame atomic absorption spectrometry determination

    Energy Technology Data Exchange (ETDEWEB)

    Molaakbari, Elaheh [Chemistry Department, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Young Research Society, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Mostafavi, Ali, E-mail: mostafavi.ali@gmail.com [Chemistry Department, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Afzali, Daryoush [Environment and Nanochemistry Department, Research Institute of Environmental Science, International Center for Science, High Technology and Environmental Science, Kerman (Iran, Islamic Republic of); Mineral Industries Research Center, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of)

    2011-01-30

    In this article, we consider ionic liquid based ultrasound-assisted dispersive liquid-liquid microextraction of trace amounts of rhodium from aqueous samples and show that this is a fast and reliable sample pre-treatment for the determination of rhodium ions by flame atomic absorption spectrometry. The Rh(III) was transferred into its complex with 2-(5-bromo-2-pyridylazo)-5-diethylamino phenol as a chelating agent, and an ultrasonic bath with the ionic liquid, 1-octyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide at room temperature was used to extract the analyte. The centrifuged rhodium complex was then enriched in the form of ionic liquid droplets and prior to its analysis by flame atomic absorption spectrometry, 300 {mu}L ethanol was added to the ionic liquid-rich phase. Finally, the influence of various parameters on the recovery of Rh(III) was optimized. Under optimum conditions, the calibration graph was linear in the range of 4.0-500.0 ng mL{sup -1}, the detection limit was 0.37 ng mL{sup -1} (3S{sub b}/m, n = 7) and the relative standard deviation was {+-}1.63% (n = 7, C = 200 ng mL{sup -1}). The results show that ionic liquid based ultrasound assisted dispersive liquid-liquid microextraction, combined with flame atomic absorption spectrometry, is a rapid, simple, sensitive and efficient analytical method for the separation and determination of trace amounts of Rh(III) ions with minimum organic solvent consumption.

  14. Ionic Liquids: Radiation Chemistry, Solvation Dynamics and Reactivity Patterns

    Energy Technology Data Exchange (ETDEWEB)

    Wishart,J.F.

    2008-09-29

    Ionic liquids (ILs) are a rapidly expanding family of condensed-phase media with important applications in energy production, nuclear fuel and waste processing, improving the efficiency and safety of industrial chemical processes, and pollution prevention. ILs are generally nonvolatile, noncombustible, highly conductive, recyclable and capable of dissolving a wide variety of materials. They are finding new uses in chemical synthesis, catalysis, separations chemistry, electrochemistry and other areas. Ionic liquids have dramatically different properties compared to conventional molecular solvents, and they provide a new and unusual environment to test our theoretical understanding of charge transfer and other reactions. We are interested in how IL properties influence physical and dynamical processes that determine the stability and lifetimes of reactive intermediates and thereby affect the courses of chemical reactions and product distributions. Successful use of ionic liquids in radiation-filled environments, where their safety advantages could be significant, requires an understanding of ionic liquid radiation chemistry. For example, characterizing the primary steps of IL radiolysis will reveal radiolytic degradation pathways and suggest ways to prevent them or mitigate their effects on the properties of the material. An understanding of ionic liquid radiation chemistry will also facilitate pulse radiolysis studies of general chemical reactivity in ILs, which will aid in the development of applications listed above. Very early in our radiolysis studies it became evident that slow solvation dynamics of the excess electron in ILs (which vary over a wide viscosity range) increases the importance of pre-solvated electron reactivity and consequently alters product distributions. Parallel studies of IL solvation phenomena using coumarin-153 dynamic Stokes shifts and polarization anisotropy decay rates are done to compare with electron solvation studies and to evaluate

  15. Partitioning Behavior of Papain in Ionic Liquids-Based Aqueous Two-Phase Systems

    Directory of Open Access Journals (Sweden)

    Zhiwen Bai

    2013-01-01

    Full Text Available This paper attempts to study and optimize the affinity partitioning conditions of papain in an aqueous two-phase system (ATPS. The effect of the amount of ionic liquids (ILs, the concentration of K2HPO4, temperature, pH, and the volume of papain solution were discussed concretely. The optimum conditions were determined as ionic liquid was 1.4 g and K2HPO4 was 1.4 g, the extraction efficiency of papain could reach 98.33% with pH unadjusted. The temperature and the pH of the solution are major parameters that influence the partitioning of protein in ILs-based ATPSs. The partition of papain to the IL-rich phase was enhanced by increasing the amount of ILs, the concentration of K2HPO4, and temperature, especially at its isoelectric point.

  16. Facilitated Ion Transport in Smectic Ordered Ionic Liquid Crystals

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Hong [Materials Architecturing Research Center, Korea Institute of Science and Technology, Hwarang-ro 14-gil 5 Seongbuk-gu Seoul 136-791 South Korea; School of Chemical and Biological Engineering and Institute of Chemical Process, Seoul National University, 599 Gwanak-ro Gwanak-gu Seoul 151-742 South Korea; Han, Kee Sung [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland WA 99354 USA; Lee, Je Seung [Department of Chemistry, Kyung Hee University, 26 Kyungheedae-ro Dongdaemun-gu Seoul 02447 South Korea; Lee, Albert S. [Materials Architecturing Research Center, Korea Institute of Science and Technology, Hwarang-ro 14-gil 5 Seongbuk-gu Seoul 136-791 South Korea; Park, Seo Kyung [Department of Chemistry, Kyung Hee University, 26 Kyungheedae-ro Dongdaemun-gu Seoul 02447 South Korea; Hong, Sung Yun [Department of Chemistry, Kyung Hee University, 26 Kyungheedae-ro Dongdaemun-gu Seoul 02447 South Korea; Lee, Jong-Chan [School of Chemical and Biological Engineering and Institute of Chemical Process, Seoul National University, 599 Gwanak-ro Gwanak-gu Seoul 151-742 South Korea; Mueller, Karl T. [Department of Chemistry, Pennsylvania State University, University Park PA 16802 USA; Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland WA 99352 USA; Hong, Soon Man [Materials Architecturing Research Center, Korea Institute of Science and Technology, Hwarang-ro 14-gil 5 Seongbuk-gu Seoul 136-791 South Korea; Nanomaterials Science and Engineering, University of Science and Technology, Gajeong-ro Yuseong-gu Daejeon 305-350 South Korea; Koo, Chong Min [Materials Architecturing Research Center, Korea Institute of Science and Technology, Hwarang-ro 14-gil 5 Seongbuk-gu Seoul 136-791 South Korea; Nanomaterials Science and Engineering, University of Science and Technology, Gajeong-ro Yuseong-gu Daejeon 305-350 South Korea

    2016-09-08

    We investigated a novel ionic mixture of an imidazolium-based room temperature IL containing ethylene oxide functionalized phosphite anion and a lithium salt that self-assembles into a smectic-ordered IL crystal. The two key features in this work are the unique origin of the smectic order of the ionic mixtures and the facilitated ion transport behavior in the smectic ordered IL crystal. In fact, the IL crystals are self-assembled through Coulombic interactions between ion species, not through the hydrophilic-phobic interactions between charged ion heads and hydrophobic long alkyl pendants or the steric interaction between mesogenic moieties. Furthermore, the smectic order in the IL crystal ionogel facilitates exceptional and remarkable ionic transport. Large ionic conductivity, viscoelastic robustness, and additional electrochemical stability of the IL crystal ionogels provide promising opportunities for future electrochemical applications.

  17. On the interfacial behavior of ionic liquids: surface tensions and contact angles.

    Science.gov (United States)

    Restolho, José; Mata, José L; Saramago, Benilde

    2009-12-01

    In this work the liquid/vapour and the solid/liquid interfaces of a series of ionic liquids: 1-ethyl-3-methylpyridinium ethyl sulfate, [EMPy][EtSO4], 1-ethyl-3-methylimidazolium ethyl sulfate, [EMIM][EtSO4], 1-ethanol-3-methylimidazolium tetrafluoroborate, [C2OHMIM][BF4], 1-butyl-3-methylimidazolium tetrafluoroborate, [BMIM][BF4], and 1-octyl-3-methylimidazolium tetrafluoroborate, [OMIM][BF4], were investigated. The surface tension was measured in a wide temperature range, (298-453) K. The contact angles were determined on substrates of different polarities. Both on the polar (glass) and the non-polar substrates ((poly-(tetrafluoroethylene) and poly-(ethylene)), the liquids with maximum and minimum surface tensions lead, respectively, to the highest and the lowest contact angles. The dispersive, gamma(L)(d), and non-dispersive, gamma(L)(nd), components of the liquid surface tension, gamma(L), were calculated from the contact angles on the non-polar substrates using the Fowkes approach. The polarity fraction, gamma(L)(nd)/gamma(L), was compared with the polarity parameter, k, obtained from the fitting of the surface tension vs. temperature data to the Eötvös equation. Good agreement was found for the extreme cases: [OMIM][BF4] exhibits the lowest polarity and [BMIM][BF4], the highest. When compared with the polarity fractions of standard liquids considered as "polar" liquids, the ionic liquids studied may be considered as moderately polar.

  18. Morphology and Ionic Conductivity of Block Copolymer Electrolytes Containing Ionic Liquids

    Science.gov (United States)

    Park, Moon Jeong

    2015-03-01

    The global energy crisis and an increase in environmental pollution in the recent years have drawn the attention of the scientific community towards the development of efficient electrochemical devices. Polymers containing charged species have the potential to serve as electrolytes in next-generation devices and achieving high ion transport properties in these electrolytes is the key to improving their efficiency. Although the synthesis and characterization of a wide variety of ion-containing polymers have been extensively reported over the last decade, quantitative understanding of the factors governing the ion transport properties of these materials is in its infancy. In this talk, I will present the current understanding of the diverse factors affecting the thermodynamics, morphologies and ion transport of ion-containing polymers by focusing on the use of ionic liquids (ILs). Various strategies for accessing improved transport properties of IL-containing polymers are elucidated by focusing on the role of IL-polymer interactions. The major accomplishment of obtaining well-defined morphologies for these IL-containing polymers by the use of block copolymer is particularly emphasized as a novel means of controlling the transport properties. The application of IL-incorporated polymer electrolytes in high temperature fuel cells and electro-active actuators is also enclosed.

  19. Physico-Chemical Properties and Phase Behaviour of Pyrrolidinium-Based Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Urszula Domańska

    2010-04-01

    Full Text Available A review of the relevant literature on 1-alkyl-1-methylpyrrolidinium-based ionic liquids has been presented. The phase diagrams for the binary systems of {1-ethyl-1-methylpyrrolidinium trifluoromethanesulfonate (triflate [EMPYR][CF3SO3] + water, or + 1-butanol} and for the binary systems of {1-propyl-1-methylpyrrolidinium trifluoromethanesulfonate (triflate [PMPYR][CF3SO3] + water, or + an alcohol (1-butanol, 1-hexanol, 1-octanol, 1-decanol} have been determined at atmospheric pressure using a dynamic method. The influence of alcohol chain length was discussed for the [PMPYR][CF3SO3]. A systematic decrease in the solubility was observed with an increase of the alkyl chain length of an alcohol. (Solid + liquid phase equilibria with complete miscibility in the liquid phase region were observed for the systems involving water and alcohols. The solubility of the ionic liquid increases as the alkyl chain length on the pyrrolidinium cation increases. The correlation of the experimental data has been carried out using the Wilson, UNIQUAC and the NRTL equations. The phase diagrams reported here have been compared to the systems published earlier with the 1-alkyl-1-methylpyrrolidinium-based ionic liquids. The influence of the cation and anion on the phase behaviour has been discussed. The basic thermal properties of pure ILs, i.e., melting temperature and the enthalpy of fusion, the solid-solid phase transition temperature and enthalpy have been measured using a differential scanning microcalorimetry technique.

  20. Phase equilibria of didecyldimethylammonium nitrate ionic liquid with water and organic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Domanska, Urszula [Physical Chemistry Division, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)]. E-mail: ula@ch.pw.edu.pl; Lugowska, Katarzyna [Physical Chemistry Division, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland); Pernak, Juliusz [Faculty of Chemical Technology, Poznan University of Technology, Poznan (Poland)

    2007-05-15

    The phase diagrams for binary mixtures of an ammonium ionic liquid, didecyldimethylammonium nitrate, [DDA][NO{sub 3}], with: alcohols (propan-1-ol, butan-1-ol, octan-1-ol, and decan-1-ol): hydrocarbons (toluene, propylbenzene, hexane, and hexadecane) and with water were determined in our laboratory. The phase equilibria were measured by a dynamic method from T 220 K to either the melting point of the ionic liquid, or to the boiling point of the solvent. A simple liquidus curve in a eutectic system was observed for [DDA][NO{sub 3}] with: alcohols (propan-1-ol, butan-1-ol, and octan-1-ol); aromatic hydrocarbons (toluene and propylbenzene) and with water. (Solid + liquid) equilibria with immiscibility in the liquid phase were detected with the aliphatic hydrocarbons heptane and hexadecane and with decan-1-ol. (Liquid + liquid) equilibria for the system [DDA][NO{sub 3}] with hexadecane was observed for the whole mole fraction range of the ionic liquid. The observation of the upper critical solution temperature in binary mixtures of ([DDA][NO{sub 3}] + decan-1-ol, heptane, or hexadecane) was limited by the boiling temperature of the solvent. Characterisation and purity of the compounds were determined by elemental analysis, water content (Fisher method) and differential scanning microcalorimetry (d.s.c.) analysis. The d.s.c. method of analysis was used to determine melting temperatures and enthalpies of fusion. The thermal stability of the ionic liquid was resolved by the thermogravimetric technique-differential thermal analysis (TG-DTA) technique over a wide temperature range from (200 to 780) K. The thermal decomposition temperature of 50% of the sample was greater than 500 K. The (solid + liquid) phase equilibria, curves were correlated by means of different G {sup Ex} models utilizing parameters derived from the (solid + liquid) equilibrium. The root-mean-square deviations of the solubility temperatures for all calculated data are dependent upon the particular

  1. SPECTROSCOPIC STUDIES OF STRUCTURE, DYNAMICS AND REACTIVITY IN IONIC LIQUIDS.

    Energy Technology Data Exchange (ETDEWEB)

    WISHART,J.F.

    2007-11-30

    Ionic liquids (ILs) are a rapidly expanding family of condensed-phase media with important applications in energy production, nuclear fuel and waste processing, improving the efficiency and safety of industrial chemical processes, and pollution prevention. ILs are generally nonvolatile, noncombustible, highly conductive, recyclable and capable of dissolving a wide variety of materials. They are finding new uses in chemical synthesis, catalysis, separations chemistry, electrochemistry and other areas. Ionic liquids have dramatically different properties compared to conventional molecular solvents, and they provide a new and unusual environment to test our theoretical understanding of charge transfer and other reactions. We are interested in how IL properties influence physical and dynamical processes that determine the stability and lifetimes of reactive intermediates and thereby affect the courses of chemical reactions and product distributions. Successful use of ionic liquids in radiation-filled environments, where their safety advantages could be significant, requires an understanding of ionic liquid radiation chemistry. For example, characterizing the primary steps of IL radiolysis will reveal radiolytic degradation pathways and suggest ways to prevent them or mitigate their effects on the properties of the material. An understanding of ionic liquid radiation chemistry will also facilitate pulse radiolysis studies of general chemical reactivity in ILs, which will aid in the development of applications listed above. Very early in our radiolysis studies it became evident that slow solvation dynamics of the excess electron in ILs (which vary over a wide viscosity range) increases the importance of pre-solvated electron reactivity and consequently alters product distributions. Parallel studies of IL solvation phenomena using coumarin-153 dynamic Stokes shifts and polarization anisotropy decay rates are done to compare with electron solvation studies and to evaluate

  2. Electrochemistry of magnesium electrolytes in ionic liquids for secondary batteries.

    Science.gov (United States)

    Vardar, Gulin; Sleightholme, Alice E S; Naruse, Junichi; Hiramatsu, Hidehiko; Siegel, Donald J; Monroe, Charles W

    2014-10-22

    The electrochemistry of Mg salts in room-temperature ionic liquids (ILs) was studied using plating/stripping voltammetry to assess the viability of IL solvents for applications in secondary Mg batteries. Borohydride (BH4(-)), trifluoromethanesulfonate (TfO(-)), and bis(trifluoromethanesulfonyl)imide (Tf2N(-)) salts of Mg were investigated. Three ILs were considered: l-n-butyl-3-methylimidazolium (BMIM)-Tf2N, N-methyl-N-propylpiperidinium (PP13)-Tf2N, and N,N-diethyl-N-methyl(2-methoxyethyl)ammonium (DEME(+)) tetrafluoroborate (BF4(-)). Salts and ILs were combined to produce binary solutions in which the anions were structurally similar or identical, if possible. Contrary to some prior reports, no salt/IL combination appeared to facilitate reversible Mg plating. In solutions containing BMIM(+), oxidative activity near 0.8 V vs Mg/Mg(2+) is likely associated with the BMIM cation, rather than Mg stripping. The absence of voltammetric signatures of Mg plating from ILs with Tf2N(-) and BF4(-) suggests that strong Mg/anion Coulombic attraction inhibits electrodeposition. Cosolvent additions to Mg(Tf2N)2/PP13-Tf2N were explored but did not result in enhanced plating/stripping activity. The results highlight the need for IL solvents or cosolvent systems that promote Mg(2+) dissociation.

  3. Sensing of Zinc-Containing Nanopollutants with an Ionic Liquid

    Directory of Open Access Journals (Sweden)

    Michelle Wang

    2010-01-01

    Full Text Available The rapid maturing of nanotechnology and its wide range of applications not bring benefits only, so the downsides are worth noting. Nanopollutants, generally undetectable, are often found as byproducts involved in various chemical or physical reactions. Many nanopollutants are concerned and suspected of causing negative impact on human health due to their unpredictable existence in the environment. Unlike the traditional sensing systems which can detect select gaseous molecules, effective nanoparticle sensing methods are still lacking in the literature. In this paper, sensing of zinc-containing nanopollutants suspended in N2 with a room-temperature ionic liquid (RTIL ([C4mim][PF6] (1-butyl-3-methyl imidazolium hexafluorophosphate has been studied. The sensitivities (RIL/Rnano obtained by determination of the RTIL resistance to the absorbed phosphor fly ash (<200 nm is 7.0, while the RTIL has higher sensitivity of 11 and 10, respectively, to ZnO and ZnS nanoparticles By component-fitted X-ray absorption near edge structure (XANES spectroscopy, it seems that the N-methyl imidazole (mim complexes are formed during sensing of the phosphor fly ash, ZnO and ZnS nanoparticles with the RTIL. The 1H and 31P NMR observations also suggest that the (mim behaves as a carrier during sensing of nanopollutants with the RTIL.

  4. EFFECTS OF GAMMA RADIATION ON ELECTROCHEMICAL PROPERTIES OF IONIC LIQUIDS

    Energy Technology Data Exchange (ETDEWEB)

    Visser, A; Nicholas Bridges, N; Thad Adams, T; John Mickalonis, J; Mark02 Williamson, M

    2009-04-21

    The electrochemical properties of ionic liquids (ILs) make them attractive for possible replacement of inorganic salts in high temperature molten salt electrochemical processing of nuclear fuel. To be a feasible replacement solvent, ILs need to be stable in moderate and high doses of radiation without adverse chemical and physical effects. Here, we exposed seven different ILs to a 1.2 MGy dose of gamma radiation to investigate their physical and chemical properties as they related to radiological stability. The azolium-based ILs experienced the greatest change in appearance, but these ILs were chemically more stable to gamma radiation than some of the other classes of ILs tested, due to the presence of aromatic electrons in the azolium ring. All the ILs exhibited a decrease in their conductivity and electrochemical window (at least 1.1 V), both of which could affect the utility of ILs in electrochemical processing. The concentration of the irradiation decomposition products was less than 3 mole %, with no impurities detectable using NMR techniques.

  5. Advanced Materials Based on Polymers and Ionic Liquids.

    Science.gov (United States)

    Kitazawa, Yuzo; Ueno, Kazuhide; Watanabe, Masayoshi

    2017-09-19

    Ionic liquids (ILs) are ambient temperature molten salts, which have attracted considerable attention owing to their unique properties. In this contribution, we review advanced materials composed of ILs and polymers for the basis of a new design protocol to fabricate novel materials. As electrolytes for electrochemical devices, cross-linked polymers containing ILs (ion gels) are endowed with functional properties inherited from ILs and mechanical consistency derived from polymers. To create such materials, micro-phase separation of block copolymers and colloidal arrays in the ILs are utilized. Based on the molecular design of task-specific ILs, the resultant ion gels are applicable as electrolytes for actuator, fuel cell, and secondary battery applications. Thermo- and photo-responsive polymers in ILs are also highlighted, whereby such stimuli elicit changes in the solubility of the self-assembly of block copolymers and colloidal arrays in the ILs. Further, thermo- and photo-reversible changes in the self-assembled structure can be exploited to demonstrate sol-gel transitions and fabricate photo-healable materials. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Hydroxycarbonylation of olefins and alcohols in ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Lapidus, A.L.; Eliseev, O.L.; Bondarenko, T.N.; Stepin, N.N. [Russian Academy of Sciences, Moscow (Russian Federation). N.D. Zelinsky Institute of Organic Chemistry

    2006-07-01

    Palladium-catalysed hydroxycarbonylation of olefins and alcohols proceeds in ionic liquid media. Terminal and internal olefins, cyclohexene, styrene, methanol, ethanol, n-butanol, cyclohexanol, benzyl alcohol and 1-phenylethanol were tested as substrates for the reaction. A number of molten salts were applied as a reaction medium and tetrabutylammonium bromide (m.p. 103 C) seemed to be the best. Carbon monoxide pressure of 2 MPa and reaction temperature of 110 C are suitable conditions to furnish the reaction in 2 hours in the presence of palladium acetate as a precursor. Triphenylphosphine added as a ligand reduces reaction rate. The critical role of counter anion in molten salt was also recognised. Yield of acids decreased in the order: Br{sup -} > Cl{sup -} > BF{sub 4} {approx}PF{sub 6}{sup -}. A two-route reaction scheme is proposed to explain the regularities of styrene and 1-phenylethanol hydroxycarbonylation. The catalytic system can be used repeatedly by simple extraction of products with diethyl ether. Nine cycles were carried out without loss of activity. (orig.)

  7. Oxidation desulfurization of fuel using pyridinium-based ionic liquids as phase-transfer catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Dishun; Wang, Yanan; Duan, Erhong; Zhang, Juan

    2010-12-15

    In this work, several ionic liquids based on pyridinium cations are prepared. The ionic liquids are employed as phase-transfer catalysts (PTCs) for phase-transfer catalytic oxidation of dibenzothiophene (DBT) dissolved in n-octane. The partition coefficients of DBT between ionic liquids and n-octane are investigated. Then H{sub 2}O{sub 2}-formic acid is used as an oxidant and ionic liquids are used as PTCs. The reaction turns to be heterogeneous and desulfurization rate of DBT increased apparently. When IL ([BPy]HSO{sub 4}) is used as PTC, and the condition are: temperature is 60 C, time is 60 min, H{sub 2}O{sub 2}/sulfur molar ratio (O/S) is 4, the desulfurization rate reaches the maximum (93.3%), and the desulfurization of the real gasoline is also investigated, 87.7% of sulfur contents are removed under optima reaction conditions. The PTC [BPy]HSO{sub 4} can be recycled for five times without significant decrease in activity. (author)

  8. Determination of proton conductivity of ionic liquids for fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Wallnofer, E.; Baumgartner, W.R.; Hacker, V. [Graz Univ. of Technology, Graz (Austria). Inst. for Chemistry and Technology of Inorganic Material

    2006-07-01

    Hydrogen fuel cells operating at temperatures of between 100 and 200 degrees C allow the catalyst to tolerate higher levels of carbon monoxide (CO) impurities. However, the number of possible materials for high temperature fuel cell electrolytes or membranes is limited. This study examined the relevant electrochemical properties of different ion liquids with specific reference to neutralized imidazole derivates with a dominant Grotthuss mechanism of proton conduction. The electrochemical stability of the ionic liquids was measured by cyclic voltammetry (CV) under nitrogen. Proton conductivity was measured under hydrogen by CV within the electrochemical limits. Hydrogen was dissolved at the anode, transported through the ionic liquid, and recombined at the cathode, so that the detected current could indicate the amount of transported hydrogen. Electrochemical impedance spectroscopy (EIS) was used to measure the frequency dependent behaviour of the ionic liquids. All measurements were conducted at 50, 100, and 150 degrees C. Results of the study showed that proton conductivity increased with higher temperatures. It was concluded that neutralized imidazole derivates with optimized side chains of the cation may prove to be a viable alternative to conventional fuel cell electrolytes. 4 refs., 2 figs.

  9. Dispersion and Solvation Effects on the Structure and Dynamics of N719 Adsorbed to Anatase Titania (101) Surfaces in Room-Temperature Ionic Liquids: An ab Initio Molecular Simulation Study

    KAUST Repository

    Byrne, Aaron

    2015-12-24

    Ab initio, density functional theory (DFT)-based molecular dynamics (MD) has been carried out to investigate the effect of explicit solvation on the dynamical and structural properties of a [bmim][NTf2] room-temperature ionic liquid (RTIL), solvating a N719 sensitizing dye adsorbed onto an anatase titania (101) surface. The effect of explicit dispersion on the properties of this dye-sensitized solar cell (DSC) interface has also been studied. Upon inclusion of dispersion interactions in simulations of the solvated system, the average separation between the cations and anions decreases by 0.6 Å; the mean distance between the cations and the surface decreases by about 0.5 Å; and the layering of the RTIL is significantly altered in the first layer surrounding the dye, with the cation being on average 1.5 Å further from the center of the dye. Inclusion of dispersion effects when a solvent is not explicitly included (to dampen longer-range interactions) can result in unphysical "kinking" of the adsorbed dye\\'s configuration. The inclusion of solvent shifts the HOMO and LUMO levels of the titania surface by +3 eV. At this interface, the interplay between the effects of dispersion and solvation combines in ways that are often subtle, such as enhancement or inhibition of specific vibrational modes. © 2015 American Chemical Society.

  10. Ionic Liquids: The Synergistic Catalytic Effect in the Synthesis of Cyclic Carbonates

    Directory of Open Access Journals (Sweden)

    Flora T.T. Ng

    2013-10-01

    Full Text Available This review presents the synergistic effect in the catalytic system of ionic liquids (ILs for the synthesis of cyclic carbonate from carbon dioxide and epoxide. The emphasis of this review is on three aspects: the catalytic system of metal-based ionic liquids, the catalytic system of hydrogen bond-promoted ionic liquids and supported ionic liquids. Metal and ionic liquids show a synergistic effect on the cycloaddition reactions of epoxides. The cations and anions of ionic liquids show a synergistic effect on the cycloaddition reactions. The functional groups in cations or supports combined with the anions have a synergistic effect on the cycloaddition reactions. Synergistic catalytic effects of ILs play an important role of promoting the cycloaddition reactions of epoxides. The design of catalytic system of ionic liquids will be possible if the synergistic effect on a molecular level is understood.

  11. Simultaneous design of ionic liquid entrainers and energy efficient azeotropic separation processes

    DEFF Research Database (Denmark)

    Roughton, Brock C.; Christian, Brianna; White, John

    2012-01-01

    design (CAMD) method and the UNIFAC-IL model is used to screen design candidates based on minimum ionic liquid concentration needed to break the azeotrope. Once the ionic liquid has been designed, the extractive distillation column for the azeotropic mixture is designed using the driving force method...... with a new proposed feed stage scaling to minimize energy inputs. Along with the distillation column, an ionic liquid recovery stage is designed and simulations are used to determine the overall heat duty for the entire process for the best ionic liquid candidates. Use of a designed ionic liquid reduces......A methodology and tool set for the simultaneous design of ionic liquid entrainers and azeotropic separation processes is presented. By adjusting the cation, anion, and alkyl chain length on the cation, the properties of the ionic liquid can be adjusted to design an entrainer for a given azeotropic...

  12. Ionic Liquid-Doped Gel Polymer Electrolyte for Flexible Lithium-Ion Polymer Batteries

    Directory of Open Access Journals (Sweden)

    Ruisi Zhang

    2015-05-01

    Full Text Available Application of gel polymer electrolytes (GPE in lithium-ion polymer batteries can address many shortcomings associated with liquid electrolyte lithium-ion batteries. Due to their physical structure, GPEs exhibit lower ion conductivity compared to their liquid counterparts. In this work, we have investigated and report improved ion conductivity in GPEs doped with ionic liquid. Samples containing ionic liquid at a variety of volume percentages (vol % were characterized for their electrochemical and ionic properties. It is concluded that excess ionic liquid can damage internal structure of the batteries and result in unwanted electrochemical reactions; however, samples containing 40–50 vol % ionic liquid exhibit superior ionic properties and lower internal resistance compared to those containing less or more ionic liquids.

  13. Ionic Liquid-Doped Gel Polymer Electrolyte for Flexible Lithium-Ion Polymer Batteries

    Science.gov (United States)

    Zhang, Ruisi; Chen, Yuanfen; Montazami, Reza

    2015-01-01

    Application of gel polymer electrolytes (GPE) in lithium-ion polymer batteries can address many shortcomings associated with liquid electrolyte lithium-ion batteries. Due to their physical structure, GPEs exhibit lower ion conductivity compared to their liquid counterparts. In this work, we have investigated and report improved ion conductivity in GPEs doped with ionic liquid. Samples containing ionic liquid at a variety of volume percentages (vol %) were characterized for their electrochemical and ionic properties. It is concluded that excess ionic liquid can damage internal structure of the batteries and result in unwanted electrochemical reactions; however, samples containing 40–50 vol % ionic liquid exhibit superior ionic properties and lower internal resistance compared to those containing less or more ionic liquids.

  14. Task-Specific Ionic Liquids for Mars Exploration (Green Chemistry for a Red Planet)

    Science.gov (United States)

    Karr, L. J.; Curreri, P. A.; Paley, M. S.; Kaukler, W. F.; Marone, M. J.

    2012-01-01

    Ionic Liquids (ILs) are organic salts with low melting points that are liquid at or near room temperature. The combinations of available ions and task-specific molecular designability make them suitable for a huge variety of tasks. Because of their low flammability, low vapor pressure, and stability in harsh environments (extreme temperatures, hard vacuum) they are generally much safer and "greener" than conventional chemicals and are thus suitable for a wide range of applications that support NASA exploration goals. This presentation describes several of the ongoing applications that are being developed at MSFC.

  15. Investigation of polymer electrolyte based on agar and ionic liquids

    Directory of Open Access Journals (Sweden)

    M. M. Silva

    2012-12-01

    Full Text Available The possibility to use natural polymer as ionic conducting matrix was investigated in this study. Samples of agarbased electrolytes with different ionic liquids were prepared and characterized by physical and chemical analyses. The ionic liquids used in this work were 1-ethyl-3-methylimidazolium ethylsulfate, [C2mim][C2SO4], 1-ethyl-3-methylimidazolium acetate, [C2mim][OAc] and trimethyl-ethanolammonium acetate, [Ch][OAc]. Samples of solvent-free electrolytes were prepared and characterized by ionic conductivity measurements, thermal analysis, electrochemical stability, X-ray diffraction, scanning electron microscopy and Fourier Transform infrared spectroscopy. Electrolyte samples are thermally stable up to approximately 190°C. All the materials synthesized are semicrystalline. The electrochemical stability domain of all samples is about 2.0 V versus Li/Li+. The preliminary studies carried out with electrochromic devices (ECDs incorporating optimized compositions have confirmed that these materials may perform as satisfactory multifunctional component layers in the field of ‘smart windows’, as well as ECD-based devices.

  16. Application of the ionic liquid Ammoeng 102 for aromatic/aliphatic hydrocarbon separation

    Energy Technology Data Exchange (ETDEWEB)

    Pereiro, A.B. [Chemical Engineering Department, Vigo University, P.O. Box 36310, Vigo (Spain)], E-mail: anab@uvigo.es; Rodriguez, A. [Chemical Engineering Department, Vigo University, P.O. Box 36310, Vigo (Spain)

    2009-08-15

    This research has been focused on a study of the ionic liquid (IL) Ammoeng 102 (tetraalkyl ammonium sulfate) as solvent in liquid-liquid extraction. Experimental densities, speeds of sound, and refractive indices of Ammoeng 102 were studied in dependence on temperature at atmospheric pressure, both by conventional techniques. The thermal expansion coefficient of the IL was calculated from the density. Experimental (liquid + liquid) equilibria data (LLE) were obtained for mixtures of (Ammoeng 102 + heptane) from T = (293.15 to 343.15) K and (heptane + toluene + Ammoeng 102) at T = 298.15 K and atmospheric pressure. The experimental results for the binary and ternary systems were well correlated with the NRTL model. Selectivity and distribution ratio values, derived from the tie-line data, were presented. A comparison with other ILs and with sulfolane is included in order to analyze the best separation solvent in a liquid extraction process.

  17. Supercritical CO2-ionic liquid mixtures for modification of organoclays.

    Science.gov (United States)

    Livi, Sébastien; Duchet-Rumeau, Jannick; Gérard, Jean-François

    2011-01-01

    The use of supercritical CO(2) as solvent in the modification of montmorillonite by imidazolium and phosphonium ionic liquids bearing long alkyl chains (C(18)) known for their excellent thermal stability is described. The objective is to combine the environmentally friendly character of ionic liquids and supercritical carbon dioxide for the organophilic treatment of lamellar silicates. Dialkyl imidazolium and alkyl phosphonium salts were synthesized to be used as new surfactants for cationic exchange of layered silicates. Then, the synthesized phosphonium (MMT-P) or imidazolium (MMT-I) modified montmorillonites, cationically exchanged under supercritical carbon dioxide with or without co-solvent, have been analyzed by thermogravimetric analysis (TGA) and X-ray diffraction (XRD) and compared to montmorillonites treated by conventional cationic exchange. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. Fabrication of Polyacrylonitrile Hollow Fiber Membranes from Ionic Liquid Solutions

    KAUST Repository

    Kim, Dooli

    2015-10-08

    The interest in green processes and products has increased to reduce the negative impact of many industrial processes to the environment. Solvents, which play a crucial role in the fabrication of membranes, need to be replaced by sustainable and less toxic solvent alternatives for commonly used polymers. The purpose of this study is the fabrication of greener hollow fiber membranes based on polyacrylonitrile (PAN), substituting dimethylformamide (DMF) by less toxic mixtures of ionic liquids (IL) and dimethylsulfoxide (DMSO). A thermodynamic analysis was conducted, estimating the Gibbs free energy of mixing to find the most convenient solution compositions. Hollow fiber membranes were manufactured and optimized. As a result, a uniform pattern and high porosity were observed in the inner surface of the membranes prepared from the ionic liquid solutions. The membranes were coated with a polyamide layer by interfacial polymerization the hollow fiber membranes were applied in forward osmosis experiments by using sucrose solutions as draw solution.

  19. Betaine and Carnitine Derivatives as Herbicidal Ionic Liquids.

    Science.gov (United States)

    Pernak, Juliusz; Niemczak, Michał; Chrzanowski, Łukasz; Ławniczak, Łukasz; Fochtman, Przemysław; Marcinkowska, Katarzyna; Praczyk, Tadeusz

    2016-08-16

    This study focused on the synthesis and subsequent characterization of herbicidal ionic liquids based on betaine and carnitine, two derivatives of amino acids, which were used as cations. Four commonly used herbicides (2,4-D, MCPA, MCPP and Dicamba) were used as anions in simple (single anion) and oligomeric (two anions) salts. The obtained salts were subjected to analyzes regarding physicochemical properties (density, viscosity, refractive index, thermal decomposition profiles and solubility) as well as evaluation of their herbicidal activity under greenhouse and field conditions, toxicity towards rats and biodegradability. The obtained results suggest that the synthesized herbicidal ionic liquids displayed low toxicity (classified as category 4 compounds) and showed similar or improved efficacy against weed compared to reference herbicides. The highest increase was observed during field trials for salts containing 2,4-D as the anion, which also exhibited the highest biodegradability (>75 %). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Sparingly soluble pesticide dissolved in ionic liquid aqueous.

    Science.gov (United States)

    Fan, Tengfei; Wu, Xuemin; Peng, Qingrong

    2014-10-02

    Ionic liquids may be considered as "environment-friendly solvents" for sparingly soluble pesticides. In this study, a series of aqueous ionic liquids (ILs) with different cations and different anions was used as environment-friendly alternative to harmful organic solvents sparingly dissolved in soluble pesticides (metolachlor, acetochlor, clethodim, thiamethoxam, and prochloraz). The aggregation behavior of aqueous ILs was investigated through surface tension measurement. Minimum area per IL molecule (Amin) values from the surface tension measurement showed that alkyl chain length and the halide anions strongly affect the aggregation behavior of ILs and the solubilization of pesticides. The solubility of metolachlor, acetochlor, clethodim, thiamethoxam, nitenpyram, and prochloraz in aqueous ILs increased. More importantly, the solubility of prochloraz in [C10mim][I] became 5771-fold higher than that in pure water. The substantially enhanced solubility of the above pesticides proved that aqueous ILs are promising environment-friendly solvents for pesticides that are commercially processed in emulsifiable concentrate (EC) formulation.

  1. The radiation stability of organic ionic liquids in biphasic systems

    Energy Technology Data Exchange (ETDEWEB)

    Howett, S.E.; Noel, J.J.; Wren, J.C., E-mail: jjnoel@uwo.ca [Univ. of Westen Ontario. London, Ontario (Canada)

    2013-07-01

    The influence of γ-radiation on the stability of biphasic water/ionic liquid (IL) and gas/IL systems was studied. The behaviours of two phosphonium-based ionic liquids with the same cation and differing anions were compared. Exposure to γ-radiation did not significantly impact IL-stability, but it did speed up processes that occurred even in the absence of radiation. The two most significant effects of irradiation were the promotion of faster emulsion layer formation and the precipitation of a fine white solid. Precipitate formation could be deleterious,whereas emulsion layer formation could be either beneficial or detrimental, in an IL-based separations process. (author)

  2. IONIC LIQUIDS: RADIATION CHEMISTRY, SOLVATION DYNAMICS AND REACTIVITY PATTERNS.

    Energy Technology Data Exchange (ETDEWEB)

    WISHART,J.F.

    2007-10-01

    energy production, nuclear fuel and waste processing, improving the efficiency and safety of industrial chemical processes, and pollution prevention. ILs are generally nonvolatile, noncombustible, highly conductive, recyclable and capable of dissolving a wide variety of materials. They are finding new uses in chemical synthesis, catalysis, separations chemistry, electrochemistry and other areas. Ionic liquids have dramatically different properties compared to conventional molecular solvents, and they provide a new and unusual environment to test our theoretical understanding of charge transfer and other reactions. We are interested in how IL properties influence physical and dynamical processes that determine the stability and lifetimes of reactive intermediates and thereby affect the courses of chemical reactions and product distributions. Successful use of ionic liquids in radiation-filled environments, where their safety advantages could be significant, requires an understanding of ionic liquid radiation chemistry. For example, characterizing the primary steps of IL radiolysis will reveal radiolytic degradation pathways and suggest ways to prevent them or mitigate their effects on the properties of the material. An understanding of ionic liquid radiation chemistry will also facilitate pulse radiolysis studies of general chemical reactivity in ILs, which will aid in the development of applications listed above. Very early in our radiolysis studies it became evident that slow solvation dynamics of the excess electron in ILs (which vary over a wide viscosity range) increases the importance of pre-solvated electron reactivity and consequently alters product distributions. Parallel studies of IL solvation phenomena using coumarin-153 dynamic Stokes shifts and polarization anisotropy decay rates are done to compare with electron solvation studies and to evaluate the influence of ILs on charge transport processes. Methods. Picosecond pulse radiolysis studies at BNL

  3. Maillard reaction products from chitosan-xylan ionic liquid solution.

    Science.gov (United States)

    Luo, Yuqiong; Ling, Yunzhi; Wang, Xiaoying; Han, Yang; Zeng, Xianjie; Sun, Runcang

    2013-10-15

    A facile method is reported to prepare Maillard reaction products (MRPs) from chitosan and xylan in co-solvent ionic liquid. UV absorbance and fluorescence changes were regarded as indicators of the occurrence of Maillard reaction. FT-IR, NMR, XRD and TG were used to investigate the structure of chitosan-xylan conjugate. The results revealed that when chitosan reacted with xylan in ionic liquid, the hydrogen bonds in chitosan were destroyed, the facts resulted in the formation of chitosan-xylan MRPs. Moreover, when the mass ratio of chitosan to xylan was 1:1, the Maillard reaction proceeded easily. In addition, relatively high antioxidant property was also noted for the chitosan-xylan conjugate with mass ratio 1:1. So the obtained chitosan-xylan MRP is a promising antioxidant agent for food industry. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Ionic Liquids: evidence of the viscosity scale-dependence.

    Science.gov (United States)

    Berrod, Quentin; Ferdeghini, Filippo; Zanotti, Jean-Marc; Judeinstein, Patrick; Lairez, Didier; García Sakai, Victoria; Czakkel, Orsolya; Fouquet, Peter; Constantin, Doru

    2017-05-22

    Ionic Liquids (ILs) are a specific class of molecular electrolytes characterized by the total absence of co-solvent. Due to their remarkable chemical and electrochemical stability, they are prime candidates for the development of safe and sustainable energy storage systems. The competition between electrostatic and van der Waals interactions leads to a property original for pure liquids: they self-organize in fluctuating nanometric aggregates. So far, this transient structuration has escaped to direct clear-cut experimental assessment. Here, we focus on a imidazolium based IL and use particle-probe rheology to (i) catch this phenomenon and (ii) highlight an unexpected consequence: the self-diffusion coefficient of the cation shows a one order of magnitude difference depending whether it is inferred at the nanometric or at the microscopic scale. As this quantity partly drives the ionic conductivity, such a peculiar property represents a strong limiting factor to the performances of ILs-based batteries.

  5. (Vapour + liquid) equilibria of ternary systems with ionic liquids using headspace gas chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtarani, Babak [Chemistry and Chemical Engineering Research Center of Iran, P.O. Box 14335-186, Tehran (Iran, Islamic Republic of); Gmehling, Juergen, E-mail: gmehling@tech.chem.uni-oldenburg.d [Carl von Ossietzky Universitaet Oldenburg, Technische Chemie, D-26111 Oldenburg (Germany)

    2010-08-15

    (Vapour + liquid) equilibrium (VLE) data for the ternary systems (hexane + benzene), (hexane + cyclohexane), (benzene + cyclohexane), and (ethanol + water) with an ionic liquid as entrainer for extractive distillation were measured by headspace gas chromatography. As ionic liquids, 1-hexyl-3-methyl-imidazolium bis (trifluoromethyl-sulfonyl) imide [HMIM][BTI], 1-octyl-3-methyl-imidazolium bis (trifluoromethyl-sulfonyl) imide [OMIM][BTI], 1-octyl-3-methyl-imidazolium trifluoro-methanesulfonate [OMIM][OTF], and 1-butyl-3-methyl-imidazolium trifluoro-methanesulfonate [BMIM][OTF] were used. The experimental data show that the ionic liquids investigated have a great influence on the separation factors of the systems (hexane + benzene), (hexane + cyclohexane), and (benzene + cyclohexane). The experimental data were compared with the predicted results using mod. UNIFAC (Do). The predicted results are in good agreement with the experimental data.

  6. Salting-out in Aqueous Solutions of Ionic Liquids and K3PO4: Aqueous Biphasic Systems and Salt Precipitation

    Directory of Open Access Journals (Sweden)

    Luís P. N. Rebelo

    2007-07-01

    Full Text Available The salting-out effect produced by the addition of potassium phosphate, K3PO4to aqueous solutions of water-miscible ionic liquids, viz. 1-ethyl-3-methylimidazoliumethyl sulfate, 1-butyl-3-methylimidazolium methyl sulfate, or 1-alkyl-3-methylimidazolium chloride (alkyl = butyl, octyl or decyl is investigated. The effects areanalyzed using both the corresponding temperature–composition pseudo-binary andcomposition ternary phase diagrams. Different regions of liquid-liquid and solid-liquidphase demixing are mapped. The phase behavior is interpreted taking into account thecomplex and competing nature of the interactions between the ionic liquid, the inorganicsalt and water. In the case of solutions containing 1-octyl- or 1-decyl-3-methylimidazoliumchloride, the smaller magnitude of the salting-out effects is explained in terms of thepossibility of self-aggregation of the ionic liquid.

  7. Ionic Liquids in Polymer Design: From Energy to Health

    Science.gov (United States)

    2016-10-19

    masters degrees Names of personnel receiving PHDs Names of other research staff Inventions (DD882) Scientific Progress This grant provided travel...at the 2015 American Chemical Society National Meeting through the POLY division at Boston, Massachusetts. This symposium was organized by Yossef A...2:30-2:45pm break 2.45-3:10pm Dynamics of Polymerized Ionic Liquids and their Monomers U Hyeok Choi, ANUJ MITTAL, Terry Price, Harry W. Gibson

  8. Synthesis and mesomorphic properties of rigid-core ionic liquid crystals

    NARCIS (Netherlands)

    Kouwer, P.H.J.; Swager, T.M.

    2007-01-01

    Ionic liquid crystals combine the unique solvent properties of ionic liquids with self-organization found for liquid crystals. We report a detailed analysis of the structure-property relationship of a series of new imidazolium-based liquid crystals with an extended aromatic core. Investigated

  9. Proton-Exchange-Induced Configuration Rearrangement in a Poly(ionic liquid) Solution: A NMR Study.

    Science.gov (United States)

    Zhu, Haijin; Yang, Hengrui; Li, Jiaye; Barlow, Kristine J; Kong, Lingxue; Mecerreyes, David; MacFarlane, Douglas R; Forsyth, Maria

    2017-11-02

    Polymeric ionic liquids have emerged recently as a promising alternative to traditional polymers as the polymer electrolyte membrane materials of choice because of their strongly decoupled dynamics between the polymer backbone and the counterions. Knowledge of proton exchange and transport mechanism in such materials is critical to the design and development of new poly(ionic liquid) materials with improved electrochemical properties. Our NMR results show that the proton exchange between the labile proton of the diethylmethylammonium (NH122) cation and H2O molecules is accompanied by a concerted configuration rearrangement of the ammonium. Through a combination of PFG-NMR and proton relaxation (line width) analysis, we demonstrate that at lower temperatures the labile proton diffuses along with the NH122 ammonium cation as an integral unit, whereas at higher temperatures the NH/H2O proton exchange sets in gradually, and the PFG-NMR measured diffusion coefficient is a population-averaged value between the two exchanging sites.

  10. First fluorinated zwitterionic micelle with unusually slow exchange in an ionic liquid.

    Science.gov (United States)

    Wang, Xiaolin; Long, Panfeng; Dong, Shuli; Hao, Jingcheng

    2013-11-26

    The micellization of a fluorinated zwitterionic surfactant in ethylammonium nitrate (EAN) was investigated. The freeze-fracture transmission electron microscope (FF-TEM) observations confirm the formation of spherical micelles with the average diameter 25.45 ± 3.74 nm. The micellization is an entropy-driven process at low temperature but an enthalpy-driven process at high temperature. Two sets of (19)F NMR signals above the critical micelle concentration (cmc) indicate that the unusually slow exchange between micelles and monomers exists in ionic liquid; meanwhile, surfactant molecules are more inclined to stay in micelle states instead of monomer states at higher concentration. Through the analysis of the half line width (Δν1/2), we can obtain the kinetic information of fluorinated zwitterionic micellization in an ionic liquid.

  11. Understanding the impact of ionic liquid pretreatment on eucalyptus

    Energy Technology Data Exchange (ETDEWEB)

    Centikol, Ozgul [Joint Bioenergy Institute; Dibble, Dean [Joint Bioenergy Institute; Cheng, Gang [Joint Bioenergy Institute; Kent, Michael S [ORNL; Knierim, Manfred [Joint Bioenergy Institute; Melnichenko, Yuri B [ORNL

    2010-01-01

    The development of cost-competitive biofuels necessitates the realization of advanced biomass pretreatment technologies. Ionic liquids provide a basis for one of the most promising pretreatment technologies and are known to allow effective processing of cellulose and some biomass species. Here, we demonstrate that the ionic liquid 1-ethyl-3-methyl imidazolium acetate, [C2mim][OAc], induces structural changes at the molecular level in the cell wall of Eucalyptus globulus. Deacetylation of xylan, acetylation of the lignin units, selective removal of guaiacyl units (increasing the syringyl:guaiacyl ratio) and decreased {beta}-ether content were the most prominent changes observed. Scanning electron microscopy images of the plant cell wall sections reveal extensive swelling during [C2mim][OAc] pretreatment. X-ray diffraction measurements indicate a change in cellulose crystal structure from cellulose I to cellulose II after [C2mim][OAc] pretreatment. Enzymatic saccharification of the pretreated material produced increased sugar yields and improved hydrolysis kinetics after [C2mim][OAc] pretreatment. These results provide new insight into the mechanism of ionic liquid pretreatment and reaffirm that this approach may be promising for the production of cellulosic biofuels from woody biomass.

  12. Exceptionally High Electric Double Layer Capacitances of Oligomeric Ionic Liquids.

    Science.gov (United States)

    Matsumoto, Michio; Shimizu, Sunao; Sotoike, Rina; Watanabe, Masayoshi; Iwasa, Yoshihiro; Itoh, Yoshimitsu; Aida, Takuzo

    2017-11-15

    Electric double layer (EDL) capacitors are promising as next-generation energy accumulators if their capacitances and operation voltages are both high. However, only few electrolytes can simultaneously fulfill these two requisites. Here we report that an oligomeric ionic liquid such as IL4 TFSI with four imidazolium ion units in its structure provides a wide electrochemical window of ∼5.0 V, similar to monomeric ionic liquids. Furthermore, electrochemical impedance measurements using Au working electrodes demonstrated that IL4 TFSI exhibits an exceptionally high EDL capacitance of ∼66 μF/cm 2 , which is ∼6 times as high as those of monomeric ionic liquids so far reported. We also found that an EDL-based field effect transistor (FET) using IL4 TFSI as a gate dielectric material and SrTiO 3 as a channel material displays a very sharp transfer curve with an enhanced carrier accumulation capability of ∼64 μF/cm 2 , as determined by Hall-effect measurements.

  13. Fabrication of Greener Membranes from Ionic Liquid Solutions

    KAUST Repository

    Kim, DooLi

    2017-06-01

    Membrane technology plays a crucial role in different separation processes such as biotechnology, pharmaceutical, and food industries, drinking water supply, and wastewater treatment. However, there is a growing concern that solvents commonly used for membrane fabrication, such as dimethylformamide (DMF), dimethylacetamide (DMAc), and 1-methyl-2-pyrrolidone (NMP), are toxic to the environment and human health. To explore the possibility of substituting these toxic solvents by less toxic or safer solvents, polymers commonly used for membrane fabrication, such as polyacrylonitrile (PAN), cellulose acetate (CA), polyethersulfone (PES), and poly(ether imide sulfone) (EXTEMTM), were dissolved in ionic liquids. Flat sheet and hollow fiber membranes were then fabricated. The thermodynamics of the polymer solutions, the kinetics of phase inversion and other factors, which resulted in significant differences in the membrane structure, compared to those of membranes fabricated from more toxic solvents, were investigated. Higher water permeance with smaller pores, unique and uniform morphologies, and narrower pore size distribution, were observed in the ionic liquid-based membranes. Furthermore, comparable performance on separation of peptides and proteins with various molecular weights was achieved with the membranes fabricated from ionic liquid solutions. In summary, we propose less hazardous polymer solutions to the environment, which can be used for the membrane fabrication with better performance and more regular morphology.

  14. Carbons, ionic liquids and quinones for electrochemical capacitors

    Directory of Open Access Journals (Sweden)

    Raul eDiaz

    2016-04-01

    Full Text Available Carbons are the main electrode materials used in electrochemical capacitors, which are electrochemical energy storage devices with high power densities and long cycling lifetimes. However, increasing their energy density will improve their potential for commercial implementation. In this regard, the use of high surface area carbons and high voltage electrolytes are well known strategies to increase the attainable energy density, and lately ionic liquids have been explored as promising alternatives to current state of the art acetonitrile-based electrolytes. Also, in terms of safety and sustainability ionic liquids are attractive electrolyte materials for electrochemical capacitors. In addition, it has been shown that the matching of the carbon pore size with the electrolyte ion size further increases the attainable electric double layer (EDL capacitance and energy density.The use of pseudocapacitive reactions can significantly increase the attainable energy density, and quinonic-based materials offer a potentially sustainable and cost effective research avenue for both the electrode and the electrolyte. This perspective will provide an overview of the current state of the art research on electrochemical capacitors based on combinations of carbons, ionic liquids and quinonic compounds, highlighting performances and challenges and discussing possible future research avenues. In this regard, current interest is mainly focused on strategies which may ultimately lead to commercially competitive sustainable high performance electrochemical capacitors for different applications including those requiring mechanical flexibility and biocompatibility.

  15. Recent Advances in Understanding the Reactivity of Energetic Ionic Liquids in Propulsion Applications

    Science.gov (United States)

    2014-08-12

    Thermal decomposition of ionic liquids – Basicity & nucleophilicity • gas phase vs. GIL model • Reactive scattering • VUV- PIMS of catalytic ionic...Obtain higher purity ionic liquid. • VUV- PIMS : – HEHN on catalyst 27 Distribution A:  Approved for public release; distribution unlimited

  16. Chemical and Electrochemical Studies in Ionic Liquids

    Science.gov (United States)

    1990-01-12

    Ambient Temperature Molten Salts Based on Organic Chloroaluminates", NATO Advanced Study Institute on Molten Salt Chemistry, University of Camerino ... Camerino , Italy, August 3 - 15, 1986. OL. Janiszeuska, P. G. Pickup, T. Zawodzinski and R. A. Osteryoung, "Electrochemically Active Polymers in

  17. Solvent extraction of gold using ionic liquid based process

    Science.gov (United States)

    Makertihartha, I. G. B. N.; Zunita, Megawati; Rizki, Z.; Dharmawijaya, P. T.

    2017-01-01

    In decades, many research and mineral processing industries are using solvent extraction technology for metal ions separation. Solvent extraction technique has been used for the purification of precious metals such as Au and Pd, and base metals such as Cu, Zn and Cd. This process uses organic compounds as solvent. Organic solvents have some undesired properties i.e. toxic, volatile, excessive used, flammable, difficult to recycle, low reusability, low Au recovery, together with the problems related to the disposal of spent extractants and diluents, even the costs associated with these processes are relatively expensive. Therefore, a lot of research have boosted into the development of safe and environmentally friendly process for Au separation. Ionic liquids (ILs) are the potential alternative for gold extraction because they possess several desirable properties, such as a the ability to expanse temperature process up to 300°C, good solvent properties for a wide range of metal ions, high selectivity, low vapor pressures, stability up to 200°C, easy preparation, environmentally friendly (commonly called as "green solvent"), and relatively low cost. This review paper is focused in investigate of some ILs that have the potentials as solvent in extraction of Au from mineral/metal alloy at various conditions (pH, temperature, and pressure). Performances of ILs extraction of Au are studied in depth, i.e. structural relationship of ILs with capability to separate Au from metal ions aggregate. Optimal extraction conditon in order to gain high percent of Au in mineral processing is also investigated.

  18. Solubilities of Solutes in Ionic Liquids from a SimplePerturbed-Hard-Sphere Theory

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Yuan; Prausnitz, John M.

    2005-09-20

    In recent years, several publications have provided solubilities of ordinary gases and liquids in ionic liquids. This work reports an initial attempt to correlate the experimental data using a perturbed-hard-sphere theory; the perturbation is based on well-known molecular physics when the solution is considered as a dielectric continuum. For this correlation, the most important input parameters are hard-sphere diameters of the solute and of the cation and anion that constitute the ionic liquid. In addition, the correlation uses the solvent density and the solute's polarizability and dipole and quadrupole moments, if any. Dispersion-energy parameters are obtained from global correlation of solubility data. Results are given for twenty solutes in several ionic liquids at normal temperatures; in addition, some results are given for gases in two molten salts at very high temperatures. Because the theory used here is much simplified, and because experimental uncertainties (especially for gaseous solutes) are often large, the accuracy of the correlation presented here is not high; in general, predicted solubilities (Henry's constants) agree with experiment to within roughly {+-} 70%. As more reliable experimental data become available, modifications in the characterizing parameters are likely to improve accuracy. Nevertheless, even in its present form, the correlation may be useful for solvent screening in engineering design.

  19. Ionic association and solvation of the ionic liquid 1-hexyl-3-methylimidazolium chloride in molecular solvents revealed by vapor pressure osmometry, conductometry, volumetry, and acoustic measurements.

    Science.gov (United States)

    Sadeghi, Rahmat; Ebrahimi, Nosaibah

    2011-11-17

    A systematic study of osmotic coefficient, conductivity, volumetric and acoustic properties of solutions of ionic liquid 1-hexyl-3-methylimidazolium chloride ([C(6)mim][Cl]) in various molecular solvents has been made at different temperatures in order to study of ionic association and solvation behavior of [C(6)mim][Cl] in different solutions. Precise measurements on electrical conductances of solutions of [C(6)mim][Cl] in water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and acetonitrile at 293.15, 298.15, and 303.15 K are reported and analyzed with Barthel's low-concentration chemical model (lcCM) to obtain the limiting molar conductivities and association constants of this ionic liquid in the investigated solvents. Strong ion pairing was found for the ionic liquid in 2-propanol, 1-butanol, and 1-propanol, whereas ion association in acetonitrile, methanol and ethanol is rather weak and in water the ionic liquid is fully dissociated. In the second part of this work, the apparent molar volumes and isentropic compressibilities of [C(6)mim][Cl] in water, methanol, ethanol, acetonitrile, 1-propanol, 2-propanol, and 1-butanol are obtained at the 288.15-313.15 K temperature range at 5 K intervals at atmospheric pressure from the precise measurements of density and sound velocity. The infinite dilution apparent molar volume and isentropic compressibility values of the free ions and ion pairs of [C(6)mim][Cl] in the investigated solvents as well as the excess molar volume of the investigated solutions are determined and their variations with temperature and type of solvents are also studied. Finally, the experimental measurements of osmotic coefficient at 318.15 K for binary solutions of [C(6)mim][Cl] in water, methanol, ethanol, 2-propanol, and acetonitrile are taken using the vapor pressure osmometry (VPO) method and from which the values of the solvent activity, vapor pressure, activity coefficients, and Gibbs free energies are calculated. The results are

  20. Volumetric properties, viscosity and refractive index of the protic ionic liquid, pyrrolidinium octanoate, in molecular solvents

    OpenAIRE

    Anouti, M.; Vigeant, A.; Jacquemin, Johan; Brigouleix, C.; Lemordant, D.

    2010-01-01

    Densities ([rho]) and viscosities ([eta]) of binary mixtures containing the Protic Ionic Liquid (PIL), pyrrolidinium octanoate with five molecular solvents: water, methanol, ethanol, n-butanol, and acetonitrile are determined at the atmospheric pressure as a function of the temperature and within the whole composition range. The refractive index of all mixtures (nD) is measured at 298.15†K. The excess molar volumes VE and deviation from additivity rules of viscosities [eta]E and refractive in...