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Sample records for ether-functionalized imidazolium ionic

  1. Optical absorption and fluorescence studies on imidazolium ionic ...

    Indian Academy of Sciences (India)

    Imidazolium ionic liquids; UV-Vis absorption; excitation wavelength-dependent fluorescence; red-edge effect; solvent effect. ... gives rise to the long absorption tail and shifting fluorescence maximum, which appears to be common to most of the imidazolium ionic liquids, is evident from the effect of the conventional solvents.

  2. Synthesis and Thermophysical Properties of Ether-Functionalized Sulfonium Ionic Liquids as Potential Electrolytes for Electrochemical Applications.

    Science.gov (United States)

    Coadou, Erwan; Goodrich, Peter; Neale, Alex R; Timperman, Laure; Hardacre, Christopher; Jacquemin, Johan; Anouti, Mérièm

    2016-12-05

    During this work, a novel series of hydrophobic room temperature ionic liquids (ILs) based on five ether functionalized sulfonium cations bearing the bis{(trifluoromethyl)sulfonyl}imide, [NTf2 ](-) anion were synthesized and characterized. Their physicochemical properties, such as density, viscosity and ionic conductivity, electrochemical window, along with thermal properties including phase transition behavior and decomposition temperature, have been measured. All of these ILs showed large liquid range temperature, low viscosity, and good conductivity. Additionally, by combining DFT calculations along with electrochemical characterization it appears that these novel ILs show good electrochemical stability windows, suitable for the potential application as electrolyte materials in electrochemical energy storage devices. ©2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  3. 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.

  4. Atomic Resolution Insights into the Structural Aggregations and Optical Properties of Neat Imidazolium-Based Ionic Liquids.

    Science.gov (United States)

    Du, Likai; Geng, Cuihuan; Zhang, Dongju; Lan, Zhenggang; Liu, Chengbu

    2016-07-14

    A fundamental understanding of the structural heterogeneity and optical properties of ionic liquids is crucial for their potential applications in catalysis, optical measurement, and solar cells. Herein, a synergistic approach combining molecular dynamics simulations, excited-state calculations, and statistical analysis was used to explore the explicit correlation between the structural and optical properties of one imidazolium amino acid-based ionic liquid, 1-butyl-3-methylimidazolium glycine. The estimated absorption spectrum successfully rationalizes the unusual and non-negligible absorption band beyond 300 nm for the neat imidazolium-based ionic liquid. The absorption behavior of imidazolium-based ionic liquids is shown to be sensitive to the details of their locally heterogeneous environments. We quantitatively highlight the imidazolium moiety and its various molecular aggregations, rather than the monomeric imidazolium moiety, that are responsible for the absorption characteristics. These results would improve our understanding of the preliminary interplay between structural heterogeneity and optical properties for neat imidazolium-based ionic liquids.

  5. 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.

  6. Dye-sensitized solar cells with ionic gel electrolytes prepared from imidazolium salts and agarose

    Energy Technology Data Exchange (ETDEWEB)

    Kazuharu, Suzuki; Makoto, Yamaguchi; Mikio, Kumagai [Institute of Research and Innovation, Photonics and Materials Research Dept., Takada, Kashiwa (Japan); Nobuo, Tanabe [Fujikura Ltd, Electronics Material Dept., Tokyo (Japan); Shozo, Yanagida [Osaka Univ. Center for Advanced Science and Innovation (Japan)

    2006-05-15

    New ionic gel electrolytes, semi-solid state electrolytes comprised of ionic liquid and gelator were investigated in order to improve the durability of dye-sensitized solar cells (DSCs). The ionic gels were prepared from agarose, natural polysaccharide, and 1-alkyl-3-methyl-imidazolium salts. The gels showed sufficient mechanical strength even though a very small amount of agarose was added (1.0-1.5 wt%). The photon to electron conversion efficiency of the DSCs containing ionic gel electrolyte was 2.93% under simulated sunlight (air mass 1.5) with a light intensity of 100 mW cm{sup -2}. (authors)

  7. 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.

  8. Reversible Deposition and Dissolution of Magnesium from Imidazolium-Based Ionic Liquids

    Directory of Open Access Journals (Sweden)

    QingSong Zhao

    2012-01-01

    Full Text Available The electrochemical performance of six imidazolium cation-based ionic liquids (ILs containing 0.3 mol L-1 Mg(CF3SO32 as the electrolytes for magnesium deposition-dissolution was examined by cyclic voltammogramms and constant current discharge-charge techniques. Scanning electron microscopy and energy dispersive X-ray spectroscopy measurements were conducted to characterize the morphologies and components of the deposits. The cathodic satiability of imidazolium cations can be improved by increasing the length of alkyls at the 1-position and introducing methyl group at the 2-position of the imidazolium cations. A reversible magnesium deposition-dissolution can be achieved at room temperature. After adding appreciate amount of tetrahydrofuran (THF organic solvent, the conductivity and the peak currents for Mg deposition and dissolution can be significantly improved. The potential polarization of deposition-dissolution process is decreased using Mg powder electrode.

  9. Sodium carbonate as phase promoter in aqueous solutions of imidazolium and pyridinium ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Deive, Francisco J. [Chemical Engineering Department, University of Santiago de Compostela, E-15782 Santiago de Compostela (Spain); Rivas, Miguel A. [Applied Physics Department, University of Vigo, 36310 Vigo (Spain); Rodriguez, Ana, E-mail: aroguez@uvigo.es [Chemical Engineering Department, University of Vigo, 36310 Vigo (Spain)

    2011-08-15

    Highlights: > The discovery of novel aqueous two-phase systems, exclusively formed by the mixture of an ionic liquid and sodium carbonate is presented. > We explore for the first time the ability of pyridinium-based ionic liquids to form aqueous biphasic systems. > A first advance of the benefits of using benzylimidazolium-based ionic liquids for aqueous two-phase systems is proposed. - Abstract: Several methylsulfate and chloride anion-based ionic liquids, such as 1-alkyl-3-methyl imidazolium methyl sulfate, C{sub n}MIM CH{sub 3}SO{sub 4} (n = 1, 2, and 4), 1-benzyl-3-methyl imidazolium methyl sulfate, BzMIM CH{sub 3}SO{sub 4}, 1-benzyl, or hexyl-3-methyl imidazolium chloride, XMIM Cl (X = Bz and Hx), and methylpyridinium methylsulfate, Mpy CH{sub 3}SO{sub 4}, with sodium carbonate, Na{sub 2}CO{sub 3}, as phase forming salt, have been investigated and discussed for their potential use in separations based on aqueous two-phase systems (ATPS). Phase diagrams have been experimentally ascertained at T = 298.15 K, and Merchuck equation and a variation of this model have been used for correlating the binodal data. The alkyl chain length in the cation and the type of anion and cation have been explored and discussed due to their decisive influence in the ATPS behavior. The consistence of tie-line data was ascertained by applying the Othmer-Tobias and Bancroft equations.

  10. Ionic liquids with symmetrical dialkoxymethyl-substituted imidazolium cations.

    Science.gov (United States)

    Pernak, Juliusz; Sobaszkiewicz, Kinga; Foksowicz-Flaczyk, Joanna

    2004-07-19

    A new one-step procedure is described for the synthesis of disubstituted imidazolium chlorides. 1,3-Dialkoxymethylimidazolium chlorides thus obtained can be employed as synthetic precursors of symmetrical ILs. The salts have been found to exhibit antimicrobial activity and an antielectrostatic effect. Their densities and viscosities have been determined and are reported herein. It has also been demonstrated that the ILs can be decomposed using an aqueous solution of KMnO(4). For each IL, the permanganate index (I(Mn)) has been estimated, which varies with the structure of cation. The only limitation of I(Mn) is the degree to which the IL dissolves in water.

  11. Imidazolium-based ionic liquids used as additives in the nanolubrication of silicon surfaces

    OpenAIRE

    Amorim, Patrícia M; Ferraria, Ana M; Colaço, Rogério; Branco, Luís C.; Saramago, Benilde

    2017-01-01

    In recent years, with the development of micro/nanoelectromechanical systems (MEMS/NEMS), the demand for efficient lubricants of silicon surfaces intensified. Although the use of ionic liquids (ILs) as additives to base oils in the lubrication of steel/steel or other types of metal/ metal tribological pairs has been investigated, the number of studies involving Si is very low. In this work, we tested imidazolium-based ILs as additives to the base oil polyethylene glycol (PEG) to lubricate Si ...

  12. On the Extraction of Aromatic Compounds from Hydrocarbons by Imidazolium Ionic Liquids

    OpenAIRE

    Jairton Dupont; Chiaro,Sandra S. X.; Bauer Ferrera; Günter Ebeling; Umpierre, Alexandre P.; Cláudia C. Cassol

    2007-01-01

    The liquid-liquid equilibrium for the ternary system formed by n-octane and aromatic (alkylbenzenes) and heteroaromatic compounds (nitrogen and sulfur containing heterocyles) and 1-alkyl-3-methylimidazolium ionic liquids (ILs) associated with various anions has been investigated. The selectivity on the extraction of a specific aromatic compound is influenced by anion volume, hydrogen bond strength between the anion and the imidazolium cation and the length of the 1-methyl-3-alkylimidazolium a...

  13. Optical absorption and fluorescence studies on imidazolium ionic ...

    Indian Academy of Sciences (India)

    Unknown

    are often described as 'designer solvents', as it is possible to design an ionic liquid with the desired properties using appropriate combinations of cationic and anionic constituents. Since application of the ionic liquids as media of photophysical studies depends on how transparent these substances are in the optical region, ...

  14. Molecular dynamics simulations of pyrrolidinium and imidazolium ionic liquids at graphene interfaces.

    Science.gov (United States)

    Begić, Srđan; Jónsson, Erlendur; Chen, Fangfang; Forsyth, Maria

    2017-11-15

    Understanding the electrode-electrolyte interface is essential in the battery research as the ion transport and ion structures at the interface most likely affect the performance of a battery. Here we investigate interfacial structures of three ionic liquids: 1-ethyl-3-methylimidazolium dicyanamide ([C2mim][dca]), 1-butyl-3-methylimidazolium dicyanamide ([C4mim][dca]) and N-butyl-N-methylpyrrolidinium dicyanamide ([C4myr][dca]) at a charged and uncharged graphene interface using molecular dynamics simulations. We find that these ionic liquids (ILs) behave differently both in the bulk phase and near a graphene interface and we find that this difference is apparent in all types of analyses performed here. First, a partial density analysis in the direction perpendicular to the surface of the electrodes, which, in the cases near a negatively charged graphene, reveals that the pyrrolidinium system is generally more layered than the imidazolium systems. Second, a 2D topographic structure analysis of the IL species in the inner layer near a negatively charged graphene surface, which reveals that the pyrrolidinium system exhibits a quasi-hexagonal surface configuration of the cations, while the imidazolium systems show linearly arranged groups of cations. Third, a 3D orientation-preference analysis of cation rings near the negative graphene electrode, which shows that the pyrrolidinium rings prefer to lie parallel to the electrode surface while the imidazolium rings prefer to stand on the electrode surface at high tilt angles. Extending the imidazolium alkyl chain was found to reduce the number of imidazoliums that can link up into linearly arranged groups in the inner layer 2D structures. Our results support earlier experimental findings and indicate that the interfacial nanostructures may have a significant influence on the electrochemical performance of IL-based batteries.

  15. Decomposition of Imidazolium-Based Ionic Liquids in Contact with Lithium Metal.

    Science.gov (United States)

    Schmitz, Paulo; Jakelski, Rene; Pyschik, Marcelina; Jalkanen, Kirsi; Nowak, Sascha; Winter, Martin; Bieker, Peter

    2017-03-09

    Ionic liquids (ILs) are considered to be suitable electrolyte components for lithium-metal batteries. Imidazolium cation based ILs were previously found to be applicable for battery systems with a lithium-metal negative electrode. However, herein it is shown that, in contrast to the well-known IL N-butyl-N-methylpyrrolidinium bis[(trifluoromethyl)sulfonyl]imide ([Pyr14 ][TFSI]), 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([C2MIm][TFSI]) and 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([C4MIm][TFSI]) are chemically unstable versus metallic lithium. A lithium-metal sheet was immersed in pure imidazolium-based IL samples and aged at 60 °C for 28 days. Afterwards, the aged IL samples were investigated to deduce possible decomposition products of the imidazolium cation. The chemical instability of the ILs in contact with lithium metal and a possible decomposition starting point are shown for the first time. Furthermore, the investigated imidazolium-based ILs can be utilized for lithium-metal batteries through the addition of the solid-electrolyte interphase (SEI) film-forming additive fluoroethylene carbonate. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Suppression of deleterious effects of free silanols in liquid chromatography by imidazolium tetrafluoroborate ionic liquids.

    Science.gov (United States)

    Kaliszan, Roman; Marszałł, Michał Piotr; Markuszewski, Michał Jan; Baczek, Tomasz; Pernak, Juliusz

    2004-03-19

    Silica-based stationary phases are commonly used in liquid chromatography, but their surface acidity causes known problems, especially when separating basic compounds. Deleterious effects of free silanols are not fully removed by standard prevention procedures consisting in adding alkylamines or other amino quenchers to the eluents. We found that ionic liquids of the imidazolium tetrafluoroborate class, added to mobile phases at concentrations of 0.5-1.5% (v/v), blocked silanols and provided excellent thin-layer chromatographic separations of strongly basic drugs which were otherwise not eluted, even with neat acetonitrile as the mobile phase. The silanol suppressing potency of imidazolium tetrafluoroborates was demonstrated to markedly exceed that of the standard mobile phase additives, like triethylamine, dimethyloctylamine and ammonia. The proposed new mobile phase additives were also demonstrated to provide reliable lipophilicity parameters of base drug analytes as determined by gradient mode of high-performance liquid chromatography. By applying the readily available and environmentally friendly imidazolium tetrafluoroborate ionic liquids, simple and efficient means of improvement of liquid chromatographic analysis of organic bases were elaborated.

  17. Absorption of carbon dioxide in aqueous solutions of imidazolium ionic liquids with carboxylate anions

    Energy Technology Data Exchange (ETDEWEB)

    Baj, Stefan; Krawczyk, Tomasz; Dabrowska, Aleksandra; Siewniak, Agnieszka [Silesian University of Technology, Gliwice (Poland); Sobolewski, Aleksander [Institute for Chemical Processing of Coal, Zabrze (Poland)

    2015-11-15

    The solubility of carbon dioxide at atmospheric pressure in aqueous mixtures of 1,3-alkyl substituted imidazolium ionic liquids (ILs) containing carboxylic anions was studied. The ILs showed increased solubility of CO{sub 2} with decreasing water concentration. The relationship between the CO{sub 2} concentration in solution and the mole fraction of water in the ILs describes a sigmoidal curve. The regression constants of a logistic function were used to quantitatively assess the absorbent capacity and the effect of water on CO{sub 2} absorption. ILs containing the most basic anions, such as pivalate, propionate and acetate, had the best properties. It was observed that the impact of water on absorption primarily depended on the cation structure. The best absorption performance was observed for 1,3-dibutylimidazolium pivalate and 1-butyl-3-methyl imidazolium acetate.

  18. Imidazolium Ionic Liquids as Potential Anti-Candida Inhibitors: QSAR Modeling and Experimental Studies.

    Science.gov (United States)

    Hodyna, Diana; Kovalishyn, Vasyl; Rogalsky, Sergiy; Blagodatnyi, Volodymyr; Metelytsia, Larisa

    2016-01-01

    Quantitative structure-activity relationships (QSAR) of imidazolium ionic liquids (ILs) as inhibitors of C. albicans collection strains (IOA-109, KCTC 1940, ATCC 10231) have been studied. Predictive QSAR models were built using different descriptor sets for a set of 88 ionic liquids with known minimum inhibitory concentrations (MIC) against C. albicans. We applied the state-of-the-art QSAR methodologies such as WEKA Random Forest (RF) as a binary classifier, Associative Neural Networks (ASNN) and k-Nearest Neighbors (k-NN) to build continuum non-linear regression models. The obtained models were validated using a 5-fold cross-validation approach and resulted in the prediction accuracies of 80% ± 5.0 for the classification models and q2 = 0.73-0.87 for the non-linear regression models. Biological testing of newly synthesized 1,3-dialkylimidazolium ionic liquids with predicted activity was performed by disco-diffusion method against C. albicans ATCC 10231 M885 strain and clinical isolates C. albicans, C. krusei and C. glabrata strains. The high percentage of coincidence between the QSAR predictions and the experimental results confirmed the high predictive power of the developed QSAR models within the applicability domain of new imidazolium ionic liquids.

  19. The role of the anion in the toxicity of imidazolium ionic liquids.

    Science.gov (United States)

    Biczak, Robert; Pawłowska, Barbara; Bałczewski, Piotr; Rychter, Piotr

    2014-06-15

    From the environmental protection point of view, the growing interest of ionic liquids in various industrial branches has raised concerns for the toxicity assessment of these compounds. The paper discusses the effect of salts containing the shared 1-ethyl-3-methylimidazolium [EMIM] cation as coupled with five different anions: bromide [Br], nitrate [NO3], p-toluenesulfonate (tosylate) [Ts], dimethylphosphate [dMP] and methanesulfonate [MS] on the growth and development of higher land plants - spring barley and common radish. The experiment was done according to the ISO Standard 11269-2:1995 and the OECD/OCDE Guide 208/2006. As the indications of phytotoxicity, the percentage of sprouts and the level of dry and fresh plant mass were used; in addition, the visual assessment of any signs of damage to the examined plant species, such as growth inhibition and chlorotic changes, was also made. Results of our study has proved the negative impact of ILs on the tested plants and the toxic effect of imidazolium salts was dependent primarily on the applied ionic liquids concentration. The common radish revealed the higher tolerance to the imidazolium as compared to spring barley. The anion type of ionic liquid was crucial for the toxicity against common radish. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. In Situ Synthesis of Imidazolium-Crosslinked Ionogels via Debus-Radziszewski Reaction Based on PAMAM Dendrimers in Imidazolium Ionic liquid.

    Science.gov (United States)

    Zhao, Xiaomeng; Guo, Shufei; Li, Hao; Liu, Jiahang; Liu, Xinxin; Song, Hongzan

    2017-11-01

    This study reports a remarkably facile method to synthesize novel ionogels with imidazolium cycle crosslinks based on polyamidoamine (PAMAM) dendrimers via one-pot, modified Debus-Radziszewski reaction in ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]). High room temperature ionic conductivity (up to 6.8 mS cm(-1) ) is achieved, and more remarkably, it can still exceed 1 mS cm(-1) when the dendrimer content reached 70% because PAMAM dendrimers are completely amorphous with many cavities and the newly formed imidazolium crosslinks contains ions. The elastic modulus of these ionogels can exceed 10(6) Pa due to the newly-formed rigid imidazolium crosslinks. Crucially, these ionogels are robust gels even at temperatures up to 160 °C. Such novel ionogels with high ionic conductivity, tunable modulus, and flexibility are desirable for use in high-temperature flexible electrochemical devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Vibration Modes at Terahertz and Infrared Frequencies of Ionic Liquids Consisting of an Imidazolium Cation and a Halogen Anion.

    Science.gov (United States)

    Yamada, Toshiki; Tominari, Yukihiro; Tanaka, Shukichi; Mizuno, Maya; Fukunaga, Kaori

    2014-11-17

    The terahertz and infrared frequency vibration modes of room-temperature ionic liquids with imidazolium cations and halogen anions were extensively investigated. There is an intermolecular vibrational mode between the imidazolium ring of an imidazolium cation, a halogen atomic anion with a large absorption coefficient and a broad bandwidth in the low THz frequency region (13-130 cm(-1)), the intramolecular vibrational modes of the alkyl-chain part of an imidazolium cation with a relatively small absorption coefficient in the mid THz frequency region (130-500 cm(-1)), the intramolecular skeletal vibrational modes of an imidazolium ring affected by the interaction between the imidazolium ring, and a halogen anion with a relatively large absorption coefficient in a high THz frequency region (500-670 cm(-1)). Interesting spectroscopic features on the interaction between imidazolium cations and halogen anions was also obtained from spectroscopic studies at IR frequencies (550-3300 cm(-1)). As far as the frequency of the intermolecular vibrational mode is concerned, we found the significance of the reduced mass in determining the intermolecular vibration frequency.

  2. Enantioselective toxicities of chiral ionic liquids 1-alkyl-3-methyl imidazolium tartrate on Scenedesmus obliquus.

    Science.gov (United States)

    Liu, Huijun; Zhang, Xiaoqiang; Dong, Ying; Chen, Caidong; Zhu, Shimin; Ma, Xiangjuan

    2015-12-01

    Ionic liquids (ILs) are being used in various industries during the last few decades, while the good solubility and high stability of ILs may pose a potential threat to the aquatic environment. Effect of chiral ionic liquids (CILs) 1-alkyl-3-methyl imidazolium tartrate (RMIM T) on Scenedesmus obliquus (S.obliquus) was studied. The growth rate inhibition and cell membrane permeability increased with increasing RMIM T concentration and increasing alkyl chain lengths. The IC50 values of D-(-)-tartrate 1-hexyl-3-methyl imidazolium (D-(-)-HMIM T) were 28.30, 12.23,10.15 and 14.41 mg/L, respectively, at 24, 48, 72 and 96h. While that of L-(+)-tartrate 1-hexyl-3-methyl imidazolium (L-(+)-HMIM T) were 15.97, 7.91, 9.43 and 12.04 mg/L respectively. The concentration of chl a, chl b and chl (a+b) decreased with increasing RMIM T concentration. The chlorophyll fluorescence parameters (F0, Fv/Fm, Fv/F0, Y(II), ETR and NPQ) were affected by RMIM T, indicating that the RMIM T will damage the PSII, inhibit the transmission of excitation energy, decrease the efficiency of photosynthesis. The results showed that there were enantioselective toxicity of RMIM T to algae, and the toxicity of L-(+)-RMIM T was greater than that of D-(-)-RMIM T, but the enantioselective difference becomes smaller with increasing exposure time, and with the increasing carbon chain length of cation, indicating that cation properties may have a larger effect on toxicity than anion properties. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. 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.

  4. Formation of ether-functionalized ionic-liquid-based aqueous two-phase systems and their application in separation of protein and saccharides.

    Science.gov (United States)

    Wang, Zhijun; Pei, Yuanchao; Zhao, Jing; Li, Zhiyong; Chen, Yujuan; Zhuo, Kelei

    2015-03-26

    Ionic-liquid (IL)-based aqueous two-phase systems (ATPSs) have attracted much attention in the separation technology. In this work, we synthesized five novel ether-functionalized ILs and studied their applications in ATPS formation. The phase diagrams for several systems were determined at 298.15 K. An as-prepared IL (1-(2-butoxy-ethyl)-3-methylimidazolium chloride) was chosen as a representative to construct ATPSs for separation of bovine serum albumin (BSA) from aqueous saccharide solutions. Results showed that 76.1-94.3% of BSA was enriched into the IL-rich top phase and almost all the saccharides were extracted into the salt-rich bottom phase in a one-step separation process. The main factors affecting the separation process, such as kinds of saccharides and the amount of inorganic salts, were discussed. Furthermore, the size distributions of aggregates in the IL-rich top phase were determined by dynamic light scattering (DLS), and accordingly the possible mechanism for the separation was investigated.

  5. Thermochemistry of imidazolium-based ionic liquids: experiment and first-principles calculations.

    Science.gov (United States)

    Verevkin, Sergey P; Emel'yanenko, Vladimir N; Zaitsau, Dzmitry H; Heintz, Andreas; Muzny, Chris D; Frenkel, Michael

    2010-12-07

    In this work the molar enthalpy of formation of the ionic liquid 1-ethyl-3-methylimidazolium dicyanoamide in the gaseous phase [C(2)MIM][N(CN)(2)] was measured by means of combustion calorimetry and enthalpy of vaporization using transpiration. Available, but scarce, primary experimental results on enthalpies of formation of imidazolium based ionic liquids with the cation [C(n)MIM] (where n = 2 and 4) and anions [N(CN)(2)], [NO(3)] and [NTf(2)] were collected and checked for consistency using a group additivity procedure. First-principles calculations of the enthalpies of formation in the gaseous phase for the ionic liquids with the common cation [C(n)MIM] (where n = 2 and 4) and with the anions [N(CN)(2)], [NO(3)], [NTf(2)], [Cl], [BF(4)] and [PF(6)] have been performed using the G3MP2 theory. It has been established that the gaseous phase enthalpies of formation of these ionic liquids obey the group additivity rules.

  6. On the Extraction of Aromatic Compounds from Hydrocarbons by Imidazolium Ionic Liquids

    Science.gov (United States)

    Cassol, Cláudia C.; Umpierre, Alexandre P.; Ebeling, Günter; Ferrera, Bauer; Chiaro, Sandra S. X.; Dupont, Jairton

    2007-01-01

    The liquid-liquid equilibrium for the ternary system formed by n-octane and aromatic (alkylbenzenes) and heteroaromatic compounds (nitrogen and sulfur containing heterocyles) and 1-alkyl-3-methylimidazolium ionic liquids (ILs) associated with various anions has been investigated. The selectivity on the extraction of a specific aromatic compound is influenced by anion volume, hydrogen bond strength between the anion and the imidazolium cation and the length of the 1-methyl-3-alkylimidazolium alkyl side chain. The interaction of alkylbenzenes and sulfur heterocyles with the IL is preferentially through CH-π hydrogen bonds and the quantity of these aromatics in the IL phase decreases with the increase of the steric hindrance imposed by the substituents on the aromatic nucleus. In the case of nitrogen heterocycles the interaction occurs preferentially through N(heteroaromatic)-H(imidazolium) hydrogen bonds and the extraction process is largely controlled by the nitrogen heterocycle pKa. Competitive extraction experiments suggest that benzene, pyridine and dibenzothiophene do not compete for the same hydrogen bond sites of the IL.

  7. Tolerance of Immobilized Yeast Cells in Imidazolium-Based Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Yu Wang

    2009-01-01

    Full Text Available Ionic liquids (ILs are considered as another ’green solvent’, after the supercritical carbon dioxide. They are a promising reaction medium for biocatalysis process. The tolerance of active cells in hydrophobic imidazolium-based ILs (1-R-3-methylimidazolium hexafluorophosphate, [RMim][PF6] has been studied in this work. Calcium-alginate-entrapped baker’s yeast has been chosen as the model of living cells. The results show that this kind of ILs possess a certain degree of biocompatibility. The tolerance of yeast cells to the ILs decreases with the increase of the R chain length of these ILs. The experiment indicated that 1-butyl-3-methylimidazolium hexafluorophosphate ([BMim][PF6] possessed excellent biocompatibility compared to the other imidazolium-based ILs. The moisture content in the ILs was the key factor that affected the tolerance. The activity retention of yeast cells pretreated with [BMim][PF6] saturated with water and aqueous [BMim][PF6] biphasic system was about 70 %, but it was only 50 % with the anhydrous [BMim][PF6]. Although the yeast cells were pretreated with [BMim][PF6] for 24 h, the activity retention was up to 45 %. The yeast cells had around 50 % activity after being pretreated 4 times with [BMim][PF6]. This shows that the water immiscible ILs possess good biocompatibility, and they are suitable for application as the reaction medium catalyzed by living cells.

  8. Tribological characteristics of aluminum alloys against steel lubricated by ammonium and imidazolium ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jun [ORNL; Blau, Peter Julian [ORNL; Dai, Sheng [ORNL; Luo, Huimin [ORNL; Meyer III, Harry M [ORNL; Truhan, John J. [Caterpillar Inc.

    2009-01-01

    Sliding friction and wear characteristics of aluminum alloys against AISI 52100 steel lubricated by ionic liquids (ILs) were investigated at both room and elevated temperatures. The tested aluminum alloys include a commercially pure aluminum Al 1100, a wrought alloy Al 6061-T6511, and a cast alloy Al 319-T6. The lubricating performance of two ILs with the same anion, one ammonium-based [C8H17]3NH.Tf2N and one imidazolium-based C10mim.Tf2N, were compared each other and benchmarked against that of a conventional fully-formulated engine oil. Significant friction (up to 35%) and wear (up to 55%) reductions were achieved by the ammonium IL when lubricating the three aluminum alloys compared to the engine oil. The imidazolium IL performed better than the oil but not as well as the ammonium IL for Al 1100 and 319 alloys. However, accelerated wear was unexpectedly observed for Al 6061 alloy when lubricated by C10mim.Tf2N. Surface chemical analyses implied complex tribochemical reactions between the aluminum surfaces and ILs during the wear testing, which has been demonstrated either beneficial by forming a protective boundary film or detrimental by causing severe tribo-corrosion. The effects of the IL cation structure, aluminum alloy composition, and tribo-testing condition on the friction and wear results have been discussed.

  9. On the Extraction of Aromatic Compounds from Hydrocarbons by Imidazolium Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Jairton Dupont

    2007-07-01

    Full Text Available The liquid-liquid equilibrium for the ternary system formed by n-octane andaromatic (alkylbenzenes and heteroaromatic compounds (nitrogen and sulfur containingheterocyles and 1-alkyl-3-methylimidazolium ionic liquids (ILs associated with variousanions has been investigated. The selectivity on the extraction of a specific aromaticcompound is influenced by anion volume, hydrogen bond strength between the anion andthe imidazolium cation and the length of the 1-methyl-3-alkylimidazolium alkyl side chain.The interaction of alkylbenzenes and sulfur heterocyles with the IL is preferentially throughCH-π hydrogen bonds and the quantity of these aromatics in the IL phase decreases withthe increase of the steric hindrance imposed by the substituents on the aromatic nucleus. Inthe case of nitrogen heterocycles the interaction occurs preferentially throughN(heteroaromatic-H(imidazolium hydrogen bonds and the extraction process is largelycontrolled by the nitrogen heterocycle pKa. Competitive extraction experiments suggestthat benzene, pyridine and dibenzothiophene do not compete for the same hydrogen bondsites of the IL.

  10. A general halide-to-anion switch for imidazolium-based ionic liquids and oligocationic systems using anion exchange resins (A- form).

    Science.gov (United States)

    Alcalde, Ermitas; Dinarès, Immaculada; Ibáñez, Anna; Mesquida, Neus

    2011-03-21

    Further studies on the application of an AER (A(-) form) method broadened the anion exchange scope of representative ionic liquids and bis(imidazolium) systems. Depending on the hydrophobicity nature of the targeted imidazolium species and counteranions, different organic solvents were used to swap halides for assorted anions, proceeding in excellent to quantitative yields.

  11. Imidazolium-based ionic liquids for cellulose pretreatment: recent progresses and future perspectives.

    Science.gov (United States)

    Cao, Yujin; Zhang, Rubing; Cheng, Tao; Guo, Jing; Xian, Mo; Liu, Huizhou

    2017-01-01

    As the most abundant biomass in nature, cellulose is considered to be an excellent feedstock to produce renewable fuels and fine chemicals. Due to its hydrogen-bonded supramolecular structure, cellulose is hardly soluble in water and most conventional organic solvents, limiting its further applications. The emergence of ionic liquids (ILs) provides an environmentally friendly, biodegradable solvent system to dissolve cellulose. This review summarizes recent advances concerning imidazolium-based ILs for cellulose pretreatment. The structure of cations and anions which has an influence on the solubility is emphasized. Methods to assist cellulose pretreatment with ILs are discussed. The state of art of the recovery, regeneration, and reuse aspects of ILs is also presented in this work. The current challenges and development directions of cellulose dissolution in ILs are put forward. Although further studies are still much required, commercialization of IL-based processes has made great progress in recent years.

  12. Supported imidazolium ionic liquid phases: a new material for solid-phase extraction.

    Science.gov (United States)

    Fontanals, Núria; Ronka, Sylwia; Borrull, Francesc; Trochimczuk, Andrzej W; Marcé, Rosa M

    2009-11-15

    This study reports a material that is based on the concept of ionic liquid analogue: a slightly crosslinked polymer-supported imidazolium trifluoroacetate salt (IL-CF(3)COO(-)) that favorably combines the properties of ionic liquids (ILs) and the advantages of a solid support. The ionic liquid-supported material was evaluated for the first time as a solid-phase extraction (SPE) sorbent for selectively and quantitatively extracting pharmaceuticals from aqueous samples. The novel IL-CF(3)COO(-) was evaluated under reversed-phase (RP), weak anion exchange (WAX), strong anion exchange (SAX) and strong cation exchange (SCX) SPE procedures, and we found that SAX conditions are the most suitable for investigating the behaviour of the IL-CF(3)COO(-) material. Under SAX conditions, the IL-CF(3)COO(-) material was capable of selectively and quantitatively extracting a group of acidic compounds from aqueous samples, while washing basic analytes that were also present in the sample. The SPE method using IL-CF(3)COO(-) material was used to analyse 1000 ml of different aqueous samples (ultrapure, tap and river) with complete recovery of the acidic compounds studied. Moreover, the method provided clean chromatogram and high recoveries when percolating complex real samples, such as 1000 ml of river water and 250 ml of effluent wastewater from a sewage treatment plant spiked at low levels with the analytes studied.

  13. Free volume investigation of imidazolium ionic liquids from positron lifetime spectroscopy

    CERN Document Server

    Yu, Yang; Krause-Rehberg, Reinhard

    2014-01-01

    In this work, relationships between the free volume and various fundamental physical properties (density, surface tension and transport properties) of ionic liquids were investigated. Two imidazolium ionic liquids 1-butyl-3-methylimidazolium tris(pentafluoroethyl)trifluoro phosphate ([C4MIM][FAP]) and 1-butyl-3-methylimidazolium bis[bis(pentafluoroethyl)phosphinyl]imide ([C4MIM][FPI]) were measured by positron annihilation lifetime spectroscopy (PALS). Changes of the ortho-positronium lifetime (o-Ps) with different states (amorphous and crystalline) were depicted as completely as possible. The mean local free (hole) volume was calculated from the o-Ps lifetime in amorphous state for the samples. Comparison between and specific volume obtained from the temperature dependent mass density gave the specific hole densities Nf and the occupied volumes Vocc. Thermal expansion of hole volume was compared with molecular volume VM of [C4MIM][FAP] and [C4MIM][FPI] as well as five other ionic liquids from our previous ...

  14. Growth inhibition and effect on photosystem by three imidazolium chloride ionic liquids in rice seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Huijun, E-mail: lhj@mail.zjgsu.edu.cn [School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang Province (China); Zhang, Shuxian [School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang Province (China); Jiaxing University, Jiaxing 314001, Zhejiang Province (China); Zhang, Xiaoqiang; Chen, Caidong [School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang Province (China)

    2015-04-09

    Highlights: • The three ILs have phytotoxic on rice growth. • The antioxidant enzyme activities increased first and then declined with ILs concentration increased. • The Hill reaction activity decreased and the PS II of leaves was damaged by ILs. • The toxicity of ILs increased as the alkyl chain length increased as the order: [OMIM]Cl < [DMIM]Cl < [C{sub 12}MIM]Cl. - Abstract: The effects of three imidazolium chloride ionic liquids (ILs) including 1-octyl-3-methylimidazolium chloride ionic liquid ([OMIM]Cl), 1-decyl-3-methylimidazolium chloride ionic liquid ([DMIM]Cl) and 1-dodecyl-3-methylimidazolium chloride ionic liquid ([C{sub 12}MIM]Cl) were studied in hydroponically grown rice seedlings. The growth inhibition rate increased and the Hill reaction activity of isolated rice chloroplasts decreased with increasing ILs concentrations. The IC{sub 50,5d} for stem length was 0.70 mg/L of [OMIM]Cl, 0.15 mg/L of [DMIM]Cl, and 0.055 mg/L of [C{sub 12}MIM]Cl, respectively. The SOD, POD and CAT activities of chloroplast exhibited initial increases followed by decreases in activity with increasing ILs concentrations. Chlorophyll fluorescence parameters such as the maximum effective quantum yield of PSII(F{sub v}/F{sub m}), the potential activity of PSII(F{sub v}/F{sub 0}), the yield of photochemical quantum [Y(II)], the photochemical quenching coefficient (qP), the non-photochemical quenching coefficient (NPQ) and the relative electron transport ratio (rETR) were affected, showing that ILs will damage the PSII. The results demonstrated that imidazolium chloride ILs are phytotoxic to rice growth and their photosystem, the toxicity increased as the alkyl chain length increased with the following order: [OMIM]Cl < [DMIM]Cl < [C{sub 12}MIM]Cl. The results will help to better understand the possible role of the defense mechanism in rice caused by ILs exposure.

  15. Characterization of hexacationic imidazolium ionic liquids as effective and highly stable gas chromatography stationary phases.

    Science.gov (United States)

    González-Álvarez, Jaime; Blanco-Gomis, Domingo; Arias-Abrodo, Pilar; Díaz-Llorente, Daniel; Ríos-Lombardía, Nicolás; Busto, Eduardo; Gotor-Fernández, Vicente; Gutiérrez-Álvarez, María D

    2012-01-01

    Polycationic ionic liquids (ILs) are an attractive class of ILs with great potential applicability as gas chromatography stationary phases. A family of hexacationic imidazolium ILs derived from the cycloalkanol family was chemically first prepared in a straightforward manner and then applied for analytical separation purposes. Four tuneable engineering vectors, namely cation ring size structure, anion nature, spatial disposition of cycloalkanol substituents and O-substitution, were considered as experimental parameters for the design of the desired ionic liquids. A total number of five new phases based on a common benzene core respectively exhibited column efficiencies around to 2500 plates/m, broad operating temperature ranges and also, even more importantly, good thermal stabilities (bleeding temperature between 260 and 365°C), finding variations in the selectivity and analytes elution orders depending on the IL structures. Their solvation characteristics were evaluated using the Abraham solvation parameter model, establishing clear correlations between their cation structure and retention capability with respect to certain analytes. The study of relationships between the ILs structure and solvation parameters gives us an idea of the IL stationary phase to be used for specific separations. Copyright © 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Effects of imidazolium chloride ionic liquids and their toxicity to Scenedesmus obliquus.

    Science.gov (United States)

    Liu, Huijun; Zhang, Xiaoqiang; Chen, Caidong; Du, Shaoting; Dong, Ying

    2015-12-01

    The low volatility of ionic liquids effectively eliminates a major pathway for environmental release and contamination; however, the good solubility, low degree of environmental degradation and biodegradation of ILs may pose a potential threat to the aquatic environment. The growth inhibition of the green alga Scenedesmus obliquus by five 1-alkyl-3-methylimidazolium chloride ionic liquids (ILs) ([Cnmim]Cl, n=6, 8, 10, 12, 16) was investigated, and the effect on cellular membrane permeability and the ultrastructural morphology by ILs ([Cnmim]Cl, n=8, 12, 16) were studied. The results showed that the growth inhibition rate increased with increasing IL concentration and increasing alkyl chain lengths. The relative toxicity was determined to be [C6mim]Cl<[C8mim]Cl<[C10mim]Cl<[C12mim]Cl<[C16mim]Cl. The algae were most sensitive to imidazolium chloride ILs at 48 h according to the results from the growth inhibition rate and cellular membrane permeability tests. The ultrastructural morphology showed that the ILs had negative effects on the cellular morphology and structure of the algae. The cell wall of treated algae became wavy and separated from the cell membrane. Chloroplast grana lamellae became obscure and loose, osmiophilic material was deposited in the chloroplast, and mitochondria and their cristae swelled. Additionally, electron-dense deposits were observed in the vacuoles. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Interactions of Aqueous Imidazolium-Based Ionic Liquid Mixtures with Solid-Supported Phospholipid Vesicles.

    Directory of Open Access Journals (Sweden)

    Patricia Losada-Pérez

    Full Text Available Despite the environmentally friendly reputation of ionic liquids (ILs, their safety has been recently questioned given their potential as cytotoxic agents. The fundamental mechanisms underlying the interactions between ILs and cells are less studied and by far not completely understood. Biomimetic films are here important biophysical model systems to elucidate fundamental aspects and mechanisms relevant for a large range of biological interaction ranging from signaling to drug reception or toxicity. Here we use dissipative quartz crystal microbalance QCM-D to examine the effect of aqueous imidazolium-based ionic liquid mixtures on solid-supported biomimetic membranes. Specifically, we assess in real time the effect of the cation chain length and the anion nature on a supported vesicle layer of the model phospholipid DMPC. Results indicate that interactions are mainly driven by the hydrophobic components of the IL, which significantly distort the layer and promote vesicle rupture. Our analyses evidence the gradual decrease of the main phase transition temperature upon increasing IL concentration, reflecting increased disorder by weakening of lipid chain interactions. The degree of rupture is significant for ILs with long hydrophobic cation chains and large hydrophobic anions whose behavior is reminiscent of that of antimicrobial peptides.

  18. 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.

  19. Progress in Imidazolium Ionic Liquids Assisted Fabrication of Carbon Nanotube and Graphene Polymer Composites

    Directory of Open Access Journals (Sweden)

    Xiaolin Xie

    2013-06-01

    Full Text Available Carbon nanotubes (CNTs and graphene sheets are the most promising fillers for polymer nanocomposites due to their superior mechanical, electrical, thermal optical and gas barrier properties, as well as high flame-retardant efficiency. The critical challenge, however, is how to uniformly disperse them into the polymer matrix to achieve a strong interface for good load transfer between the two. This problem is not new but more acute in CNTs and graphene, both because they are intrinsically insoluble and tend to aggregate into bundles and because their surfaces are atomically smooth. Over the past decade, imidazolium ionic liquids (Imi-ILs have played a multifunctional role (e.g., as solvents, dispersants, stabilizers, compatibilizers, modifiers and additives in the fabrication of polymer composites containing CNTs or graphene. In this review, we first summarize the liquid-phase exfoliation, stabilization, dispersion of CNTs and graphene in Imi-ILs, as well as the chemical and/or thermal reduction of graphene oxide to graphene with the aid of Imi-ILs. We then present a full survey of the literature on the Imi-ILs assisted fabrication of CNTs and graphene-based nanocomposites with a variety of polymers, including fluoropolymers, hydrocarbon polymers, polyacrylates, cellulose and polymeric ionic liquids. Finally, we give a future outlook in hopes of facilitating progress in this emerging area.

  20. Imidazolium Ionic Liquid Modified Graphene Oxide: As a Reinforcing Filler and Catalyst in Epoxy Resin

    Directory of Open Access Journals (Sweden)

    Qing Lyu

    2017-09-01

    Full Text Available Surface modification of graphene oxide (GO is one of the most important issues to produce high performance GO/epoxy composites. In this paper, the imidazole ionic liquid (IMD-Si was introduced onto the surface of GO sheets by a cheap and simple method, to prepare a reinforcing filler, as well as a catalyst in epoxy resin. The interlayer spacing of GO sheets was obviously increased by the intercalation of IMD-Si, which strongly facilitated the dispersibility of graphene oxide in organic solvents and epoxy matrix. The addition of 0.4 wt % imidazolium ionic liquid modified graphene oxide (IMD-Si@GO, yielded a 12% increase in flexural strength (141.3 MPa, a 26% increase in flexural modulus (4.69 GPa, and a 52% increase in impact strength (18.7 kJ/m2, compared to the neat epoxy. Additionally the IMD-Si@GO sheets could catalyze the curing reaction of epoxy resin-anhydride system significantly. Moreover, the improved thermal conductivities and thermal stabilities of epoxy composites filled with IMD-Si@GO were also demonstrated.

  1. DFT study of the energetic and noncovalent interactions between imidazolium ionic liquids and hydrofluoric acid.

    Science.gov (United States)

    Velarde, Marco V; Gallo, Marco; Alonso, P A; Miranda, A D; Dominguez, J M

    2015-04-16

    In this work, we evaluated the energetic interactions between imidazolium ionic liquids (ILs) and hydrofluoric acid, as well as the cation-anion interactions in ILs. We used DFT calculations that include dispersion corrections employing the PBE and M06 functionals. We tested 22 ILs, including [C4MIM][PF6], [C4MIM][NTf2], and [C4MIM][CH3COO], obtaining interaction energies in the range of -27 to -13 kcal/mol with the PBE functional. The NCI (noncovalent interaction) index developed by Yang and collaborators ( J. Am. Chem. Soc. 2010 , 132 , 6498 - 6506 ; J. Chem. Theory Comput. 2011 , 7 , 625 - 632 ) also was used for mapping the key noncovalent interactions (hydrogen bonds, van der Waals, and steric repulsions) between the anions and cations of ILs and also for interactions of ILs with hydrofluoric acid (HF). The results obtained show that the anions have a stronger effect with respect to cations in their capacity for interacting with hydrofluoric acid, and the strongest interaction energies occur in systems where the key noncovalent interactions are mainly hydrogen bonds. The [C4MIM][PF6], [C4MIM][NTf2], and [C4MIM][BF4] ionic liquids displayed the weakest cation-anion interactions.

  2. Long alkyl-chain imidazolium ionic liquids: Antibiofilm activity against phototrophic biofilms.

    Science.gov (United States)

    Reddy, G Kiran Kumar; Nancharaiah, Y V; Venugopalan, V P

    2017-07-01

    Biofilm formation is problematic and hence undesirable in medical and industrial settings. In addition to bacteria, phototrophic organisms are an integral component of biofilms that develop on surfaces immersed in natural waters. 1-Alkyl-3-methyl imidazolium ionic liquids (IL) with varying alkyl chain length were evaluated for their influence on the formation of monospecies (Navicula sp.) and multispecies biofilms under phototrophic conditions. An IL with a long alkyl side chain, 1-hexadecyl-3-methylimidaazolium chloride ([C 16 (MIM)][Cl]) retarded growth, adhesion and biofilm formation of Navicula sp. at concentrations as low as 5μM. Interestingly, [C 16 (MIM)][Cl] was very effective in preventing multispecies phototrophic biofilms on fibre reinforced plastic surfaces immersed in natural waters (fresh and seawater). SYTOX ® Green staining and chlorophyll leakage assay confirmed that the biocidal activity of the IL was exerted through cell membrane disruption. The data show that [C 16 (MIM)][Cl] is a potent inhibitor of phototrophic biofilms at micromolar concentrations and a promising agent for biofilm control in re-circulating cooling water systems. This is the first report that ionic liquids inhibit biofilm formation by phototrophic organisms which are important members of biofilms in streams and cooling towers. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Experiment and DFT studies on radioiodine removal and storage mechanism by imidazolium-based ionic liquid.

    Science.gov (United States)

    Cao, Bobo; Liu, Shuangyue; Du, Dongmei; Xue, Zhimin; Fu, Hui; Sun, Haitao

    2016-03-01

    In order to remove and store radioactive substances effectively, studies on the mechanisms of radioiodine captured by ionic liquids (ILs) with a fixed cation (1-butyl-3-methyl-imidazolium cation [Bmim]+) were carried out in experimental and theoretical methods. Fourier transform infrared attenuated total reflectance (FT-IR ATR) spectra of 2BP8HQ and ultraviolet-visible (UV/vis) spectroscopy were used to investigate the kinetic process of radioiodine removal by ILs in experiment. Corresponding theoretical investigations on the structures and formation mechanisms of ILs, bare anions and complexes as well as hydrogen bonds was carried using density functional theory. The electrostatic potential was used in configuration design and construction. Charge distribution was used to show the variation of atom charge density, Interaction energy and vibration frequency change were performed to explore possible mechanisms on the halogen bond formation between radioiodine molecule and bare anion or anion in ILs when radioiodine captured by ILs. In order to characterize halogen bonds both natural bond orbital analysis and atoms in molecules analysis were performed. Both experimental and computational results showed that radioiodine could be captured by ILs with a 1:1mol stoichiometry. It was noteworthy that [Bmim][Br], [Bmim][I] and [Bmim][Cl], containing high radioiodine capture efficiency anions, were better candidates in removal and reliable storage of radioiodine for their capture efficiencies of over 80% in 5h. Copyright © 2016. Published by Elsevier Inc.

  4. Size-controlled synthesis of chalcogen and chalcogenide nanoparticles using protic ionic liquids with imidazolium cation

    Energy Technology Data Exchange (ETDEWEB)

    Meenatchi, Boominathan [Cauvery College for Women, Tamilnadu (India); Renuga, Velayutham [National College, Tamilnadu (India); Manikandan, Ayyar [Bharath Institute of Higher Education and Research, Bharath University, Tamilnadu (India)

    2016-03-15

    Green synthesis of selenium (chalcogen) nanoparticles (SeNPs) has been successfully attained by simple wet chemical method that involves the reaction of six different protic ionic liquids with imidazolium cations and sodium hydrogen selenide (NaHSe) in the presence of poly ethylene glycol-600 (PEG-600) as an additional stabilizer. The obtained SeNPs were characterized using UV spectral (UV), Fourier transform infra-red (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal analysis (DTA), scanning electron microscope (SEM) with energy dispersive X-ray (EDX) and high resolution transmission electron microscope (TEM) analysis. The results illustrate that the synthesized SeNPs are spherical in shape with size ranging 19-24 nm and possess good optical property with greater band gap energy, high thermal stability up to 330 .deg. C, low melting point of 218-220 .deg. C comparing to precursor selenium. Using the synthesized SeNPs, two chalcogenides such as ZnSe and CdSe semiconductor nanoparticles were synthesized and characterized using XRD, SEM with EDX and TEM analysis. The fabricated CdSe and ZnSe nanoparticles appeared like pebble and cluster structure with particle size of 29.97 nm and 22.73 nm respectively.

  5. Micellization and interfacial behavior of imidazolium-based ionic liquids in organic solvent-water mixtures.

    Science.gov (United States)

    Pino, Verónica; Yao, Cong; Anderson, Jared L

    2009-05-15

    The surface and micellar properties of aqueous solutions of two imidazolium-based ionic liquids (ILs), 1-hexadecyl-3-butylimidazolium bromide (HDBIm-Br) and 1,3-didodecylimidazolium bromide (DDDDIm-Br), are examined in the presence of several organic solvents by surface tensiometry. The organic solvents studied include methanol, 1-propanol, 1-butanol, 1-pentanol, and acetonitrile. Increases in the critical micelle concentration (cmc) values were obtained for both ILs when increasing the organic solvent content with a more significant increase observed for the DDDDIm-Br IL. For both ILs, decreases in the maximum surface excess concentration (Gamma(max)), increases in the minimum surface area per surfactant molecule (A(min)), decreases in the adsorption efficiency (pC(20)), and decreases in the effectiveness of surface tension reduction (Pi(cmc)) were obtained when increasing the organic solvent content. However, the studied organic solvents affect the surface tension at the cmc (gamma(cmc)) differently; generating increases for DDDDIm-Br and decreases for HDBIm-Br. These changes can be linked to the different water-air interface orientation of both ILs in aqueous solutions free of organic solvents. Linear correlations between the extent of the change in these parameters when increasing the alkyl-chain of the alcohol modifier were also observed. A preliminary study of the utilization of HDBIm-Br in micellar-liquid chromatography (MLC) is also presented, demonstrating the applicability of the IL-aggregates in this analytical technique.

  6. Thermodynamics of hydrogen bonding and van der Waals interactions of organic solutes in solutions of imidazolium based ionic liquids: “Structure-property” relationships

    Energy Technology Data Exchange (ETDEWEB)

    Varfolomeev, Mikhail A., E-mail: vma.ksu@gmail.com; Khachatrian, Artashes A.; Akhmadeev, Bulat S.; Solomonov, Boris N.

    2016-06-10

    Highlights: • Solution enthalpies of organic solutes in imidazolium based ionic liquids were measured. • van der Waals interactions scale of imidazolium based ionic liquids was proposed. • Enthalpies of solvation of organic solutes in ionic liquids were determined. • Hydrogen bond enthalpies of organic solutes with ionic liquids were calculated. • Relationships between structure of ionic liquids and thermochemical data were obtained. - Abstract: In the present work thermochemistry of intermolecular interactions of organic compounds in solutions of imidazolium based ionic liquids (ILs) has been studied using solution calorimetry method. Enthalpies of solution at infinite dilution of non-polar (alkanes, aromatic hydrocarbons) and polar (alcohols, amides, and etc.) organic solutes in two ionic liquids 1-butyl-3-methylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium trifluoromethanesulfonate were measured at 298.15 K. The scale of van der Waals interactions of imidazolium based ILs has been proposed on the basis of solution enthalpies of n-alkanes in their media. The effect of the cation and anion structure of ILs on the enthalpies of solvation was analyzed. Enthalpies of hydrogen bonding of organic solutes with imidazolium based ILs were determined. It has been shown that these values are close to zero for proton acceptor solutes. At the same time, enthalpies of hydrogen bonding of proton donor solutes with ionic liquids are increased depending the anion: tetrafluoroborate ≈ bis(trifluoromethylsulfonyl)imide < 2-(2-methoxyethoxy)ethyl sulfate < trifluoromethanesulfonate. Enthalpies of van der Waals interactions and hydrogen bonding in the solutions of imidazolium based ionic liquids were compared with the same data for molecular solvents.

  7. Increased enantioselectivity and remarkable acceleration of lipase-catalyzed transesterification by using an imidazolium PEG-alkyl sulfate ionic liquid.

    Science.gov (United States)

    Itoh, Toshiyuki; Matsushita, Yuichi; Abe, Yoshikazu; Han, Shi-Hui; Wada, Shohei; Hayase, Shuichi; Kawatsura, Motoi; Takai, Shigeomi; Morimoto, Minoru; Hirose, Yoshihiko

    2006-12-13

    Several types of imidazolium salt ionic liquids were prepared derived from poly(oxyethylene)alkyl sulfate and used as an additive or coating material for lipase-catalyzed transesterification in an organic solvent. A remarkably increased enantioselectivity was obtained when the salt was added at 3-10 mol % versus substrate in the Burkholderia cepacia lipase (lipase PS-C)-catalyzed transesterification of 1-phenylethanol by using vinyl acetate in diisopropyl ether or a hexane solvent system. In particular, a remarkable acceleration was accomplished by the ionic liquid coating with lipase PS in an iPr(2)O solvent system while maintaining excellent enantioselectivity; it reached approximately 500- to 1000-fold acceleration for some substrates with excellent enantioselectivity. A similar acceleration was also observed for IL 1-coated Candida rugosa lipase. MALDI-TOF mass spectrometry experiments of the ionic-liquid-coated lipase PS suggest that ionic liquid binds with lipase protein.

  8. A nanostarch functionalized ionic liquid containing imidazolium cation and cobalt chelate anion for the synthesis of carbamates from amines and dimethyl carbonate.

    Science.gov (United States)

    Kumar, Subodh; Jain, Suman L

    2013-11-14

    A new nanostarch functionalized ionic liquid containing imidazolium cation and cobalt chelate anion was synthesized and tested for the one pot synthesis of carbamates by the reaction of amines and dimethyl carbonate (DMC), affording excellent yield of the products under solvent free mild reaction conditions. The synthesized ionic liquid was easily recovered and reused several times without any loss in catalytic efficiency.

  9. Synthesis, spectroscopic and molecular docking studies of imidazolium and pyridinium based ionic liquids with HSA as potential antimicrobial agents

    Science.gov (United States)

    Trush, Maria M.; Semenyuta, Ivan V.; Vdovenko, Sergey I.; Rogalsky, Sergiy P.; Lobko, Evgeniya O.; Metelytsia, Larisa O.

    2017-06-01

    The interaction between human serum albumin (HSA) and synthesized imidazolium and pyridinium based ionic liquids (ILs), as good potential microbial growth inhibitors, was investigated by spectroscopic techniques combined with molecular docking analysis. All compounds were significant active against the tested bacterial and fungal strains. FT-IR spectroscopy indicated that the interaction of HSA with ILs generates considerable changes in protein secondary structure. The results of the molecular docking study showed that the studied ILs are able to firmly bind in the subdomain IIA of HSA with almost equal binding affinity (about -6.23 kcal/mol). Investigated HSA-ILs complex binds through hydrogen bonding or/and cation-π interactions. This study provides a better understanding of the binding of imidazolium and pyridinium based ILs to HSA and opens the way for their further biological and pharmaceutical investigations as candidates with antimicrobial properties.

  10. Alkyl-imidazolium glycosides: non-ionic-cationic hybrid surfactants from renewable resources.

    Science.gov (United States)

    Salman, Abbas Abdulameer; Tabandeh, Mojtaba; Heidelberg, Thorsten; Hussen, Rusnah Syahila Duali; Ali, Hapipah Mohd

    2015-08-14

    A series of surfactants combining carbohydrate and imidazolium head groups were prepared and investigated on their assembly behavior. The presence of the imidazolium group dominated the interactions of the surfactants, leading to high CMCs and large molecular surface areas, reflected in curved rather than lamellar surfactant assemblies. The carbohydrate, on the other hand, stabilized molecular assemblies slightly and reduced the surface tension of surfactant solutions considerably. A comparative emulsion study discourages the use of pure alkyl imidazolium glycosides owing to reduced assembly stabilities compared with APGs. However, the surfactants are believed to have potential as component in carbohydrate based surfactant mixtures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Corrosion inhibition performance of imidazolium ionic liquids and their influence on surface ferrous carbonate layer formation

    Science.gov (United States)

    Yang, Dongrui

    Corrosion inhibitors as effective anti-corrosion applications were widely studied and drawn much attention in both academe and industrial area. In this work, a systematic work, including inhibitors selection, anti-corrosion property and characterization, influence on scale formation, testing system design and so on, were reported. The corrosion inhibition performance of four imidazolium ionic liquids in carbon dioxide saturated NaCl solution was investigated by using electrochemical and surface analysis technologies. The four compounds are 1-ethyl-3-methylimidazolium chloride (a), 1-butyl-3-methylimidazolium chloride (b), 1-hexyl-3-methylimidazolium chloride (c), 1-decyl-3-methylimidazolium chloride (d). Under the testing conditions, compound d showed the highest inhibition efficiency and selected as the main object of further study. As a selected representative formula, 1-decyl-3-methylimidazolium chloride was studied in detail about its corrosion inhibition performance on mild steel in carbon dioxide saturated NaCl brine at pH 3.8 and 6.8. Electrochemical and surface analysis techniques were used to characterize the specimen corrosion process during the immersion in the blank and inhibiting solutions. The precorrosion of specimen surface showed significant and different influences on the anti-corrosion property of DMICL at pH 3.8 and 6.8. The corrosion inhibition efficiency (IE) was calculated based on parameters obtained from electrochemical techniques; the achieved IE was higher than 98% at the 25th hour for the steel with a well-polished surface at pH 3.8. The fitting parameters obtained from electrochemical data helped to account for the interfacial changes. As proved in previous research, 1-decyl-3-methylimidazolium chloride could be used as good corrosion inhibitors under certain conditions. However, under other conditions, such chemicals, as well as other species in oil transporting system, could be a factor influencing the evolution of protective surface

  12. Imidazolium-based ionic liquids used as additives in the nanolubrication of silicon surfaces

    Directory of Open Access Journals (Sweden)

    Patrícia M. Amorim

    2017-09-01

    Full Text Available In recent years, with the development of micro/nanoelectromechanical systems (MEMS/NEMS, the demand for efficient lubricants of silicon surfaces intensified. Although the use of ionic liquids (ILs as additives to base oils in the lubrication of steel/steel or other types of metal/ metal tribological pairs has been investigated, the number of studies involving Si is very low. In this work, we tested imidazolium-based ILs as additives to the base oil polyethylene glycol (PEG to lubricate Si surfaces. The friction coefficients were measured in a nanotribometer. The viscosity of the PEG + IL mixtures as well as their contact angles on the Si surface were measured. The topography and chemical composition of the substrates surfaces were determined with atomic force microscopy (AFM and X-ray photoelectron spectroscopy (XPS, respectively. Due to the hygroscopic properties of PEG, the first step was to assess the effect of the presence of water. Then, a series of ILs based on the cations 1-ethyl-3-methylimidazolium [EMIM], 1-butyl-3-methylimidazolium [BMIM], 1-ethyl-3-vinylimidazolium [EVIM], 1-(2-hydroxyethyl-3-methylimidazolium [C2OHMIM] and 1-allyl-3-methylimidazolium [AMIM] combined with the anions dicyanamide [DCA], trifluoromethanesulfonate [TfO], and ethylsulfate [EtSO4] were added to dry PEG. All additives (2 wt % led to a decrease in friction coefficient as well as an increase in viscosity (with the exception of [AMIM][TfO] and improved the Si wettability. The additives based on the anion [EtSO4] exhibited the most promising tribological behavior, which was attributed to the strong interaction with the Si surface ensuring the formation of a stable surface layer, which hinders the contact between the sliding surfaces.

  13. Imidazolium-based ionic liquids used as additives in the nanolubrication of silicon surfaces.

    Science.gov (United States)

    Amorim, Patrícia M; Ferraria, Ana M; Colaço, Rogério; Branco, Luís C; Saramago, Benilde

    2017-01-01

    In recent years, with the development of micro/nanoelectromechanical systems (MEMS/NEMS), the demand for efficient lubricants of silicon surfaces intensified. Although the use of ionic liquids (ILs) as additives to base oils in the lubrication of steel/steel or other types of metal/ metal tribological pairs has been investigated, the number of studies involving Si is very low. In this work, we tested imidazolium-based ILs as additives to the base oil polyethylene glycol (PEG) to lubricate Si surfaces. The friction coefficients were measured in a nanotribometer. The viscosity of the PEG + IL mixtures as well as their contact angles on the Si surface were measured. The topography and chemical composition of the substrates surfaces were determined with atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), respectively. Due to the hygroscopic properties of PEG, the first step was to assess the effect of the presence of water. Then, a series of ILs based on the cations 1-ethyl-3-methylimidazolium [EMIM], 1-butyl-3-methylimidazolium [BMIM], 1-ethyl-3-vinylimidazolium [EVIM], 1-(2-hydroxyethyl)-3-methylimidazolium [C 2 OHMIM] and 1-allyl-3-methylimidazolium [AMIM] combined with the anions dicyanamide [DCA], trifluoromethanesulfonate [TfO], and ethylsulfate [EtSO 4 ] were added to dry PEG. All additives (2 wt %) led to a decrease in friction coefficient as well as an increase in viscosity (with the exception of [AMIM][TfO]) and improved the Si wettability. The additives based on the anion [EtSO 4 ] exhibited the most promising tribological behavior, which was attributed to the strong interaction with the Si surface ensuring the formation of a stable surface layer, which hinders the contact between the sliding surfaces.

  14. Theoretical study of the effect of π^{+}-π^{+} association in imidazolium ionic liquids at charged interfaces.

    Science.gov (United States)

    Ma, Ke; Forsman, Jan; Woodward, Clifford E

    2017-12-01

    We develop an extended classical density-functional theory to describe clustering of imidazolium-based cations into linear chains, driven by π-π stacking. We find that the associating system displays a similar short-ranged structure to the completely dissociated fluid. We also construct a restricted primitive model for associating ionic species in an RTIL+solvent mixture. The double-layer formed in these systems exhibits strong overscreening by the cation chains, as expected. Significantly enhanced capacitance is also observed for the case where counterions are the associating species. The established density-functional method can be also used to describe polydisperse polyelectrolyte models.

  15. Theoretical study of the effect of π+-π+ association in imidazolium ionic liquids at charged interfaces

    Science.gov (United States)

    Ma, Ke; Forsman, Jan; Woodward, Clifford E.

    2017-12-01

    We develop an extended classical density-functional theory to describe clustering of imidazolium-based cations into linear chains, driven by π -π stacking. We find that the associating system displays a similar short-ranged structure to the completely dissociated fluid. We also construct a restricted primitive model for associating ionic species in an RTIL+solvent mixture. The double-layer formed in these systems exhibits strong overscreening by the cation chains, as expected. Significantly enhanced capacitance is also observed for the case where counterions are the associating species. The established density-functional method can be also used to describe polydisperse polyelectrolyte models.

  16. Application of Chromatographic and Electrophoretic Methods for the Analysis of Imidazolium and Pyridinium Cations as Used in Ionic Liquids

    Directory of Open Access Journals (Sweden)

    P. Stepnowski

    2006-11-01

    Full Text Available Interest in ionic liquids for their potential in different chemical processes isconstantly increasing, as they are claimed to be environmentally benign – excellent, non-volatile solvents for a wide range of applications. The wide applicability of thesecompounds also demands reliable, relatively simple and reproducible analytical techniques.These methods must be applicable not only to different technical or natural matrices but alsoto the very low concentrations that are likely to be present in biological and environmentalsystems. In this review, therefore, methods for separating and analysing imidazolium- andpyridinium-type ionic liquids in aqueous matrices using high performance liquidchromatography (HPLC and capillary electrophoresis (CE are examined. The techniquesfor identifying ionic liquids are meant primarily to track the concentrations of ionic liquidsas residues not only in products and wastes but also in biological or environmental samples.The application of hyphenated techniques in this field is intended to selectively separate thequaternary entity from other cationic and non-ionic species present in the matrix, and toenable its fine-scale quantification. Nowadays, methods developed for cation analysis arebased mostly on reversed-phase high-performance liquid chromatography, ionchromatography, ion-pair chromatography and capillary electrophoresis, where variousbuffered mobile phases are used.

  17. Study of the Imidazolium-Based Ionic Liquid - ag Electrified Interface on the CO_{2} Electroreduction by Sum Frequency Spectroscopy.

    Science.gov (United States)

    Garcia Rey, Natalia; Dlott, Dana

    2017-06-01

    Imidazolium based ionic liquids (ILs) have been used as a promising system to improve the CO_{2} electroreduction at lower overpotential than other organic or aqueous electrolytes^{1}. Although the detailed mechanism of the CO_{2} electroreduction on Ag has not been elucidated yet, we have developed a methodology to study the electrified interface during the CO_{2} electroreduction using sum frequency generation (SFG) spectroscopy in combination with cyclic voltammetry^{2}. In this work, we tuned the composition of imidazolium-based ILs by exchanging the anion or the functional groups of the imidazolium. We use the nonresonant SFG (NR-SFG) to study the IL-Ag interface and resonant SFG (RES-SFG) to identify the CO adsorbed on the electrode and monitor the Stark shift as a function of cell potential. In previous studies on CO_{2} electroreduction in the IL: 1-ethyl-3-methylimidazolium tetrafluorborate (EMIM-BF_{4}) on Ag, we showed three events occurred at the same potential (-1.33 V vs. Ag/AgCl): the current associated with CO_{2} electroreduction increased, the Stark shift of the adsorbed atop CO doubled in magnitude and the EMIM-BF_{4} underwent a structural transition^{3}. In addition, we also observed how the structural transition of the EMIM-BF_{4} electrolyte shift to lower potentials when the IL is mixed with water. It is known that water enhances the CO_{2} electroreduction producing more CO^{4}. Moreover, the CO is adsorbed in multi-bonded and in atop sites when more water is present in the electrolyte. ^{1}Lau, G. P. S.; Schreier, M.; Vasilyev, D.; Scopelliti, R.; Grätzel, M.; Dyson, P. J., New Insights into the Role of Imidazolium-Based Promoters for the Electroreduction of CO_{2} on a Silver Electrode. J. Am. Chem. Soc. 2016, 138, 7820-7823. ^{2}Garcia Rey, N.; Dlott, D. D., Studies of Electrochemical Interfaces by Broadband Sum Frequency Generation. J. Electroanal. Chem. 2016. DOI:10.1016/j.jelechem.2016.12.023. ^{3}Garcia Rey, N.; Dlott, D. D

  18. Significance of weak interactions in imidazolium picrate ionic liquids: spectroscopic and theoretical studies for molecular level understanding.

    Science.gov (United States)

    Panja, Sumit Kumar; Dwivedi, Nidhi; Noothalapati, Hemanth; Shigeto, Shinsuke; Sikder, A K; Saha, Abhijit; Sunkari, Sailaja S; Saha, Satyen

    2015-07-21

    The effects of interionic hydrogen bonding and π-π stacking interactions on the physical properties of a new series of picrate anion based ionic liquids (ILs) have been investigated experimentally and theoretically. The existence of aromatic (C2-HO) and aliphatic (C7-HO-N22 and C6-HO-N20) hydrogen bonding and π-π stacking interactions in these ILs has been observed using various spectroscopic techniques. The aromatic and aliphatic C-HO hydrogen bonding interactions are found to have a crucial role in binding the imidazolium cation and picrate anion together. However, the π-π stacking interactions between two successive layers are found to play a decisive role in tight packing in ILs leading to differences in physical properties. The drastic difference in the melting points of the methyl and propyl derivatives (mmimPic and pmimPic respectively) have been found to be primarily due to the difference in the strength and varieties of π-π stacking interactions. While in mmimPic, several different types of π-π stacking interactions between the aromatic rings (such as picrate-picrate, picrate-imidazole and imidazolium-imidazolium cation rings) are observed, only one type of π-π stacking interaction (picrate-picrate rings) is found to exist in the pmimPic IL. NMR spectroscopic studies reveal that the interaction of these ILs with solvent molecules is different and depends on the dielectric constant of the solvent. While an ion solvation model explains the solvation in high dielectric solvents, an ion-pair solvation model is found to be more appropriate for low dielectric constant solvents. The enhanced stability of these investigated picrate ILs compared with that of inorganic picrate salts under high doses of γ radiation clearly indicates the importance of weak interionic interactions in ILs, and also opens up the possibility of the application of picrate ILs as prospective diluents in nuclear separation for advanced fuel cycling process.

  19. Interplay of phase separation, tail aggregation, and micelle formation in the nanostructured organization of hydrated imidazolium ionic liquid.

    Science.gov (United States)

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

    2014-07-24

    A molecular investigation on the effect of water on structural properties of imidazolium-based ionic liquids (ILs) is essential due to its various industrial applications. In this work, we employ molecular dynamics simulations to characterize the influence of various water concentrations on nanostructural properties of the 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [Hmim][NTf2] IL. An examination of molecular interactions in [Hmim][NTf2] IL-water mixtures shows the following trends: (a) At low water concentration, small regions of water molecules are surrounded by several cation-anion pairs. (b) At medium water concentration, cation tail aggregation starts, and phase separation between the IL and water is observed. (c) At high water concentration, increasing cationic tail aggregation leads to micelle formation. Further aggregates of cations and anions are solvated by large water channels. The radial distribution functions show that cation-anion, cation-cation, and anion-anion interactions decrease and water-water interaction increases with water concentration. The hydrogen bonding interactions occur between the acidic hydrogen of the positively charged imidazolium cation with the nitrogen and oxygen atoms of the anions. However, no hydrogen bonding interactions are seen between water molecules and the hydrophobic anions.

  20. Self-assembled thin film of imidazolium ionic liquid on a silicon surface: Low friction and remarkable wear-resistivity

    Energy Technology Data Exchange (ETDEWEB)

    Gusain, Rashi [CSIR-Indian Institute of Petroleum, Mohkampur, Dehardun 248005 (India); Academy of Scientific and Innovative Research, New Delhi 110025 (India); Kokufu, Sho [Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501 (Japan); Bakshi, Paramjeet S. [CSIR-Indian Institute of Petroleum, Mohkampur, Dehardun 248005 (India); Utsunomiya, Toru; Ichii, Takashi; Sugimura, Hiroyuki [Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501 (Japan); Khatri, Om P., E-mail: opkhatri@iip.res.in [CSIR-Indian Institute of Petroleum, Mohkampur, Dehardun 248005 (India); Academy of Scientific and Innovative Research, New Delhi 110025 (India)

    2016-02-28

    Graphical abstract: - Highlights: • Ionic liquid thin film is deposited on a silicon surface via covalent interaction. • Chemical and morphological features of ionic liquid thin film are probed by XPS and AFM. • Ionic liquid thin film exhibited low and steady friction along with remarkable wear-resistivity. - Abstract: Imidazolium-hexafluorophosphate (ImPF{sub 6}) ionic liquid thin film is prepared on a silicon surface using 3-chloropropyltrimethoxysilane as a bifunctional chemical linker. XPS result revealed the covalent grafting of ImPF{sub 6} thin film on a silicon surface. The atomic force microscopic images demonstrated that the ImPF{sub 6} thin film is composed of nanoscopic pads/clusters with height of 3–7 nm. Microtribological properties in terms of coefficient of friction and wear-resistivity are probed at the mean Hertzian contact pressure of 0.35–0.6 GPa under the rotational sliding contact. The ImPF{sub 6} thin film exhibited low and steady coefficient of friction (μ = 0.11) along with remarkable wear-resistivity to protect the underlying silicon substrate. The low shear strength of ImPF{sub 6} thin film, the covalent interaction between ImPF{sub 6} ionic liquid thin film and underlying silicon substrate, and its regular grafting collectively reduced the friction and improved the anti-wear property. The covalently grafted ionic liquid thin film further shows immense potential to expand the durability and lifetime of M/NEMS based devices with significant reduction of the friction.

  1. Biomedical exploitation of chitin and chitosan via mechano-chemical disassembly, electrospinning, dissolution in imidazolium ionic liquids, and supercritical drying.

    Science.gov (United States)

    Muzzarelli, Riccardo A A

    2011-01-01

    Recently developed technology permits to optimize simultaneously surface area, porosity, density, rigidity and surface morphology of chitin-derived materials of biomedical interest. Safe and ecofriendly disassembly of chitin has superseded the dangerous acid hydrolysis and provides higher yields and scaling-up possibilities: the chitosan nanofibrils are finding applications in reinforced bone scaffolds and composite dressings for dermal wounds. Electrospun chitosan nanofibers, in the form of biocompatible thin mats and non-wovens, are being actively studied: composites of gelatin + chitosan + polyurethane have been proposed for cardiac valves and for nerve conduits; fibers are also manufactured from electrospun particles that self-assemble during subsequent freeze-drying. Ionic liquids (salts of alkylated imidazolium) are suitable as non-aqueous solvents that permit desirable reactions to occur for drug delivery purposes. Gel drying with supercritical CO(2) leads to structures most similar to the extracellular matrix, even when the chitosan is crosslinked, or in combination with metal oxides of interest in orthopedics.

  2. Preparation and properties of titania based ionogels synthesized using ionic liquid 1-ethyl-3-methyl imidazolium thiocyanate

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Y.L.; Tripathi, A.K.; Shalu; Singh, V.K.; Balo, L.; Gupta, H.; Singh, S.K.; Singh, R.K., E-mail: rajendrasingh.bhu@gmail.com

    2017-06-15

    Highlights: • Synthesis of titania based ionogels using non-aqueous sol-gel process. • Ionogels are found to be mesoporous structure with uniform pore size distribution. • Ionic liquid extracted TiO{sub 2} matrix reveals the anatase phase of TiO{sub 2}. • Properties of ionic liquid are found to change in TiO{sub 2} matrix. - Abstract: Present study reports the synthesis of titania (TiO{sub 2}) based ionogels using ionic liquid (IL) 1-ethyl-3-methyl imidazolium thiocyanate ([EMIM][SCN]) by non-aqueous sol-gel process. Ionogels are characterized using N{sub 2} adsorption-desorption, TGA, DSC, SEM, TEM, XRD, and FTIR. N{sub 2}-sorption results show that TiO{sub 2} matrices have meso-pores with uniform pore size distribution. Thermal studies reveal that thermal stability of confined IL decreases while the glass transition temperature (T{sub g}) is found to increase. XRD patterns show that IL containing TiO{sub 2} matrices exhibit amorphous (weak crystalline peaks) nature however after extraction of IL from ionogel, it shows the crystalline (anatase) phase of TiO{sub 2} which has also been found from SAED pattern. SEM micrographs reveal that as the amount of IL is increased, TiO{sub 2} particles are found to agglomerate. FTIR results indicate that the vibrational frequencies of confined IL are found to shift due to interaction of IL molecules with titania pore wall surface.

  3. Ionic Conductivity and Assembled Structures of Imidazolium Salt-Based Block Copolymers with Thermoresponsive Segments

    OpenAIRE

    Kazuhiro Nakabayashi; Yu Sato; Yuta Isawa; Chen-Tsyr Lo; Hideharu Mori

    2017-01-01

    Ionic liquid-based block copolymers composed of ionic (solubility tunable)–nonionic (water-soluble and thermoresponsive) segments were synthesized to explore the relationship between ionic conductivity and assembled structures. Three block copolymers, comprising poly(N-vinylimidazolium bromide) (poly(NVI-Br)) as a hydrophilic poly(ionic liquid) segment and thermoresponsive poly(N-isopropylacrylamide) (poly(NIPAM)), having different compositions, were initially prepared by RAFT polymerization....

  4. Indirect ultraviolet detection of alkaline earth metal ions using an imidazolium ionic liquid as an ultraviolet absorption reagent in ion chromatography.

    Science.gov (United States)

    Liu, Yong-Qiang; Yu, Hong

    2017-04-01

    A convenient and versatile method was developed for the separation and detection of alkaline earth metal ions by ion chromatography with indirect UV detection. The chromatographic separation of Mg2+ , Ca2+ , and Sr2+ was performed on a carboxylic acid base cation exchange column using imidazolium ionic liquid/acid as the mobile phase, in which the imidazolium ionic liquid acted as an UV-absorption reagent. The effects of imidazolium ionic liquids, detection wavelength, acids in the mobile phase, and column temperature on the retention of Mg2+ , Ca2+ , and Sr2+ were investigated. The main factors influencing the separation and detection were the background UV absorption reagent and the concentration of hydrogen ion in ion chromatography with indirect UV detection. The successful separation and detection of Mg2+ , Ca2+ , and Sr2+ within 14 min were achieved using the selected chromatographic conditions, and the detection limits (S/N = 3) were 0.06, 0.12, and 0.23 mg/L, respectively. A new separation and detection method of alkaline earth metal ions by ion chromatography with indirect UV detection was developed, and the application range of ionic liquids was expanded. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Dicationic imidazolium ionic liquid modified silica as a novel reversed-phase/anion-exchange mixed-mode stationary phase for high-performance liquid chromatography.

    Science.gov (United States)

    Sun, Min; Feng, Juanjuan; Wang, Xiaojiao; Duan, Huimin; Li, Leilei; Luo, Chuannan

    2014-08-01

    A dicationic imidazolium ionic liquid modified silica stationary phase was prepared and evaluated by reversed-phase/anion-exchange mixed-mode chromatography. Model compounds (polycyclic aromatic hydrocarbons and anilines) were separated well on the column by reversed-phase chromatography; inorganic anions (bromate, bromide, nitrate, iodide, and thiocyanate), and organic anions (p-aminobenzoic acid, p-anilinesulfonic acid, sodium benzoate, pathalic acid, and salicylic acid) were also separated individually by anion-exchange chromatography. Based on the multiple sites of the stationary phase, the column could separate 14 solutes containing the above series of analytes in one run. The dicationic imidazolium ionic liquid modified silica can interact with hydrophobic analytes by the hydrophobic C6 chain; it can enhance selectivity to aromatic compounds by imidazolium groups; and it also provided anion-exchange and electrostatic interactions with ionic solutes. Compared with a monocationic ionic liquid functionalized stationary phase, the new stationary phase represented enhanced selectivity owing to more interaction sites. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Synthesis and application of imidazolium-based ionic liquids as extraction solvent for pretreatment of triazole fungicides in water samples.

    Science.gov (United States)

    Yang, Jiale; Fan, Chen; Kong, Dandan; Tang, Gang; Zhang, Wenbing; Dong, Hongqiang; Liang, You; Wang, Deng; Cao, Yongsong

    2018-02-01

    Five novel ionic liquids (ILs), 1,3-dibutylimidazolium bromide [BBMIm][Br], 1-pentyl-3-butylimidazolium bromide [BPMIm][Br], 1-hexyl-3-butylimidazolium bromide [BHMIm][Br], 1,1'-(butane-1,4-diyl)bis(3-butylimidazolium) bromide [C 4 (BMIm) 2 ][Br 2 ], and 1,1'-(butane-1,4-diyl)bis(3-methylimidazolium) bromide [C 4 (MIm) 2 ][Br 2 ], were prepared and used in situ to react with bis(trifluoromethane)sulfonamide lithium salt to extract the myclobutanil, tebuconazole, cyproconazole, and prothioconazole from water samples. The results showed that mono-cationic ILs had much better recovery than dicationic ILs, and mono-imidazolium IL bearing butyl groups at N-1 and N-3 sites had the best recovery. When the length of the alkyl substituent group was more than four carbons at N-3 site, the recovery decreased with increase of alkyl chain length of 1-butylimidazolium IL. The extraction efficiency order of triazoles from high to low was [BBMIm][Br], [BPMIm][Br], [BHMIm][Br], [BMIm][Br] (1-butyl-3-methylimidazolium bromide), [C 4 (BMIm) 2 ]Br 2 , [C 4 (MIm) 2 ]Br 2 . An in situ ionic liquid dispersive liquid-liquid microextraction combined with ultrasmall superparamagnetic Fe 3 O 4 was established as a pretreatment method for enrichment of triazole fungicides in water samples by using the synthetic [BBMIm][Br] as the cationic IL and used to detect analytes followed by high-performance liquid chromatography. Under the optimized conditions, the proposed method showed a good linearity within a range of 5-250 μg L -1 , with the determination coefficient (r 2 ) varying from 0.998 to 0.999. High mean enrichment factors were achieved ranging from 187 to 323, and the recoveries of the target analytes from real water samples at spiking levels of 10.0, 20.0, and 50.0 μg L -1 were between 70.1% and 115.0%. The limits of detection for the analytes were 0.74-1.44 μg L -1 , and the intra-day relative standard deviations varied from 5.23% to 8.65%. The proposed method can be further applied

  7. Sugarcane bagasse pretreatment using three imidazolium-based ionic liquids; mass balances and enzyme kinetics

    National Research Council Canada - National Science Library

    Karatzos, Sergios Kimon; Edye, Leslie Alan; Doherty, William Orlando Sinclair

    2012-01-01

    Effective pretreatment is key to achieving high enzymatic saccharification efficiency in processing lignocellulosic biomass to fermentable sugars, biofuels and value-added products. Ionic liquids (ILs...

  8. New Ether-functionalized Morpholinium- and Piperidinium-based Ionic Liquids as Electrolyte Components in Lithium and Lithium-Ion Batteries.

    Science.gov (United States)

    Navarra, Maria Assunta; Fujimura, Kanae; Sgambetterra, Mirko; Tsurumaki, Akiko; Panero, Stefania; Nakamura, Nobuhumi; Ohno, Hiroyuki; Scrosati, Bruno

    2017-06-09

    Here, two ionic liquids, N-ethoxyethyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide (M1,2O2 TFSI) and N-ethoxyethyl-N-methylpiperidinium bis(trifluoromethanesulfonyl)imide (P1,2O2 TFSI) were synthesized and compared. Fundamental relevant properties, such as thermal and electrochemical stability, density, and ionic conductivity were analyzed to evaluate the effects caused by the presence of the ether bond in the side chain and/or in the organic cation ring. Upon lithium salt addition, two electrolytes suitable for lithium batteries applications were found. Higher conducting properties of the piperidinium-based electrolyte resulted in enhanced cycling performances when tested with LiFePO4 (LFP) cathode in lithium cells. When mixing the P1,2O2 TFSI/LiTFSI electrolyte with a tailored alkyl carbonate mixture, the cycling performance of both Li and Li-ion cells greatly improved, with prolonged cyclability delivering very stable capacity values, as high as the theoretical one in the case of Li/LFP cell configurations. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Ionic Liquid-Derived Imidazolium Cation Linkers for the Layer-by-Layer Assembly of Polyoxometalate-MWCNT Composite Electrodes with High Power Capability.

    Science.gov (United States)

    Genovese, Matthew; Lian, Keryn

    2016-07-27

    Imidazolium cations derived from ionic liquids were demonstrated as effective linker molecules for the layer-by-layer (LbL) deposition of polyoxometalates (POMs) to increase the charge storage of multi-walled carbon nanotube (MWCNT) electrodes. MWCNTs modified with GeMo12O40(4-) (GeMo12) via an imidazolium cation linker demonstrated highly reversible redox reactions and a capacitance of 84 F cm(-3), close to 4 times larger than bare CNT. Compared to CNT-GeMo12 composites fabricated with a conventional polyelectrolyte linker poly(diallyldimethylammonium chloride), (PDDA), the imidazolium cations resulted in lower POM loading, but higher conductivity and in turn superior performance at fast charge-discharge conditions. A polymerized imidazolium linker (PIL) was also synthesized based on the ethyl-vinyl-imidazolium monomer. CNT-GeMo12 composites fabricated with this PIL achieved high POM loading comparable to PDDA, while still maintaining the good conductivity and high rate capabilities shown by the monomer imidazolium units. The high conductivity imparted by the PIL is especially valuable for the fabrication of multilayer POM composites. Dual-layer GeMo12 O40(4-)-SiMo12O40(4-) (GeMo12-SiMo12) electrodes built with this PIL demonstrated a combined contribution of the individual POMs resulting in a capacitance of 191 F cm(-3), over nine times larger than bare MWCNT. The PIL dual layer composites also maintained 72% of this capacitance at a fast rate of 2 V s(-1), compared to just over 50% retention for similar electrodes fabricated with PDDA.

  10. Electrochemical Stability Window of Imidazolium-Based Ionic Liquids as Electrolytes for Lithium Batteries.

    Science.gov (United States)

    Kazemiabnavi, Saeed; Zhang, Zhengcheng; Thornton, Katsuyo; Banerjee, Soumik

    2016-06-30

    This paper presents the computational assessment of the electrochemical stability of a series of alkyl methylimidazolium-based ionic liquids for their use as lithium battery electrolytes. The oxidation and reduction potentials of the constituent cation and anion of each ionic liquid with respect to a Li(+)/Li reference electrode were calculated using density functional theory following the method of thermodynamic cycles, and the electrochemical stability windows (ESW)s of these ionic liquids were obtained. The effect of varying the length of alkyl side chains of the methylimidazolium-based cations on the redox potentials and ESWs was investigated. The results show that the limits of the ESWs of these methylimidazolium-based ionic liquids are defined by the oxidation potential of the anions and the reduction potential of alkyl-methylimidazolium cations. Moreover, ionic liquids with [PF6](-) anion have a wider ESW. In addition to characterizing structure-function relationships, the accuracy of the computational approach was assessed through comparisons of the data against experimental measurements of ESWs. The potentials calculated by the thermodynamic cycle method are in good agreement with the experimental data while the HOMO/LUMO method overestimates the redox potentials. This work demonstrates that these approaches can provide guidance in selecting ionic liquid electrolytes when designing high-voltage rechargeable batteries.

  11. Ionic Conductivity and Assembled Structures of Imidazolium Salt-Based Block Copolymers with Thermoresponsive Segments

    Directory of Open Access Journals (Sweden)

    Kazuhiro Nakabayashi

    2017-11-01

    Full Text Available Ionic liquid-based block copolymers composed of ionic (solubility tunable–nonionic (water-soluble and thermoresponsive segments were synthesized to explore the relationship between ionic conductivity and assembled structures. Three block copolymers, comprising poly(N-vinylimidazolium bromide (poly(NVI-Br as a hydrophilic poly(ionic liquid segment and thermoresponsive poly(N-isopropylacrylamide (poly(NIPAM, having different compositions, were initially prepared by RAFT polymerization. The anion-exchange reaction of the poly(NVI-Br in the block copolymers with lithium bis(trifluoromethanesulfonylimide (LiNTf2 proceeded selectively to afford amphiphilic block copolymers composed of hydrophobic poly(NVI-NTf2 and hydrophilic poly(NIPAM. Resulting poly(NVI-NTf2-b-poly(NIPAM exhibited ionic conductivities greater than 10−3 S/cm at 90 °C and 10−4 S/cm at 25 °C, which can be tuned by the comonomer composition and addition of a molten salt. Temperature-dependent ionic conductivity and assembled structures of these block copolymers were investigated, in terms of the comonomer composition, nature of counter anion and sample preparation procedure.

  12. Determination of cmc of imidazolium based surface active ionic liquids through probe-less UV-vis spectrophotometry.

    Science.gov (United States)

    Rather, Mudasir Ahmad; Rather, Ghulam Mohammad; Pandit, Sarwar Ahmad; Bhat, Sajad Ahmad; Bhat, Mohsin Ahmad

    2015-01-01

    In the first of its kind we herein report the results of our studies undertaken on the micellization behaviour of imidazolium based surface active ionic liquids (SAILs) to prove that their critical micelle concentration (cmc) can be estimated through ultraviolet-visible (UV-vis) spectroscopy without using any external probe. Tensiometric and spectrophotometric investigations of a series of freshly prepared SAILs viz. 1-octyl-3-methylimidazolium chloride ([OMIM][Cl]), 1-octyl-3-methylimidazolium dodecylsulphate ([OMIM][DS]), 1-octyl-3-methylimidazolium benzoate ([OMIM][Bz]), 1-octyl-3-methylimidazolium salicylate ([OMIM][Sc]), 1-octyl-3-methylimidazolium acetate ([OMIM][Ac]) are presented as a case study in support of the said claim. The cmcs estimated through spectrophotometric method were found to be close to the values estimated through tensiometry for the said SAILs. The cmcs for the investigated SAILS were found to vary in order of [OMIM][Cl]>[OMIM][Ac]>[OMIM][Bz]>[OMIM][Sc]>[OMIM][DS]. To the best of our knowledge the present communication will be the first report about the synthesis, characterization and micellization behaviour of [OMIM][Bz] and [OMIM][Sc]. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Aggregation behavior and antimicrobial activity of ester-functionalized imidazolium- and pyridinium-based ionic liquids in aqueous solution.

    Science.gov (United States)

    Garcia, M Teresa; Ribosa, Isabel; Perez, Lourdes; Manresa, Angeles; Comelles, Francesc

    2013-02-26

    Two series of long chain imidazolium- and pyridinium-based ionic liquids containing an ester functional group in the alkyl side chain, 3-methyl-1-alkyloxycarbonylmethylimidazolium bromides (C(n)EMeImBr) and 1-alkyloxycarbonylmethylpyridinium bromides (C(n)EPyrBr), were synthesized and their thermal stability, aggregation behavior in aqueous medium, and antimicrobial activity investigated. The introduction of an ester group decreased the thermal stability of the functionalized ILs compared to simple alkyl chain containing ILs (1-alkyl-3-methylimidazolium bromides and 1-alkylpyridinium bromides). Tensiometry, conductimetry, and spectrofluorimetry were applied to study the self-aggregation of the amphiphilic ILs in aqueous solution. The ILs investigated displayed surface activity and the characteristic chain length dependence of the micellization process of surfactants. As compared to simple alkyl chain containing ILs bearing the same hydrocarbon chain, ester-functionalized ILs possess higher adsorption efficiency (pC(20)) and significantly lower critical micelle concentration (cmc) and surface tension at the cmc (γ(cmc)), indicating that the incorporation of an ester group promotes adsorption at the air/water interface and micelle formation. The antimicrobial activity was evaluated against Gram-negative and Gram-positive bacteria and fungi. ILs containing more than eight carbon atoms in the alkyl chain showed antimicrobial activity. Their efficiency as antimicrobial agents increased with the hydrophobicity of the amphiphilic cation being the C(12) homologous the most active compounds. The incorporation of an ester group particularly increased the biological activity against fungi.

  14. Recombination of photogenerated lophyl radicals in imidazolium-based ionic liquids.

    Science.gov (United States)

    Strehmel, Veronika; Wishart, James F; Polyansky, Dmitry E; Strehmel, Bernd

    2009-12-07

    Laser flash photolysis is applied to study the recombination reaction of lophyl radicals in ionic liquids in comparison with dimethylsulfoxide as an example of a traditional organic solvent. The latter exhibits a similar micropolarity as the ionic liquids. The ionic liquids investigated are 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (1), 1-hexyl-3-methylimidazolium hexafluorophosphate (2), and 1-butyl-3-methylimidazolium tetafluoroborate (3). The recombination of the photolytic generated lophyl radicals occur significantly faster in the ionic liquids than expected from their macroscopic viscosities and is a specific effect of these ionic liquids. On the other hand, this reaction can be compared with the macroscopic viscosity in the case of dimethylsulfoxide. Activation parameters obtained for lophyl radical recombination suggest different, anion-dependent mechanistic effects. Quantum chemical calculations based on density functional theory provide a deeper insight of the molecular properties of the lophyl radical and its precursor. Thus, excitation energies, spin densities, molar volumes, and partial charges are calculated. Calculations show a spread of spin density over the three carbon atoms of the imidazolyl moiety, while only low spin density is calculated for the nitrogens.

  15. Electrochemical Studies on Uranyl Chloride Complexes in 1-Butyl-3-methyl-imidazolium Based Ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Yasuhisa Ikeda; Katsuyuki Hiroe; Nobutaka Ohta; Masanobu Nogami; Atsushi Shirai [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology 2-12-1-N1-34 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Noriko Asanuma [Department of Energy Science and Engineering, Tokai University 1117 Kitakaname, Hiratsuka-shi, Kanagawa 259-1292 (Japan)

    2008-07-01

    Sample solutions were prepared by dissolving UO{sub 2}Cl{sub 2}-nH{sub 2}O or Cs{sub 2}UO{sub 2}Cl{sub 4} into 1-butyl-3-methyl-imidazolium chloride (BMICl). Their UV-visible absorption spectra showed that uranyl species in BMICl exist as [UO{sub 2}Cl{sub 4}]{sup 2-}. Cyclic voltammograms were measured using a glassy carbon working electrode, a platinum wire counter electrode, and an Ag/AgCl reference electrode with a liquid junction filled with BMIBF{sub 4} at 80 {+-} 1 deg. C in glove box under an Ar atmosphere. Peaks of one redox couple were observed at around -0.73 V and -0.65 V on both systems. Potential differences between two peaks ({delta}E{sub p}) at scan rates in the range of 10 to 50 mV/s are 70 - 80 mV, which are almost consistent with theoretical {delta}E{sub p} value (67 mV) for the reversible one electron transfer reaction at 80 deg. C. From these results, it is concluded that [UO{sub 2}Cl{sub 4}]{sup 2-} in BMICl is reduced quasi-reversibly to [UO{sub 2}Cl{sub 4}]{sup 3-}. (authors)

  16. Theoretical Insight into the Conversion Mechanism of Glucose to Fructose Catalyzed by CrCl2 in Imidazolium Chlorine Ionic Liquids.

    Science.gov (United States)

    Jing, Yaru; Gao, Jun; Liu, Chengbu; Zhang, Dongju

    2017-03-09

    To better understand the efficient transformation of glucose to fructose catalyzed by chromium chlorides in imidazolium-based ionic liquids (ILs), density functional theory calculations have been carried out on a model system which describes the catalytic reaction by CrCl2 in 1,3-dimethylimidazolium chlorine (MMImCl) ionic liquid (IL). The reaction is shown to involve three fundamental processes: ring opening, 1,2-H migration, and ring closure. The reaction is calculated to exergonic by 3.8 kcal/mol with an overall barrier of 37.1 kcal/mol. Throughout all elementary steps, both CrCl2 and MMImCl are found to play substantial roles. The Cr center, as a Lewis acid, coordinates to two hydroxyl group oxygen atoms of glucose to bidentally rivet the substrate, and the imidazolium cation plays a dual role of proton shuttle and H-bond donor due to its intrinsic acidic property, while the Cl- anion is identified as a Bronsted/Lewis base and also a H-bond acceptor. Our present calculations emphasize that in the rate-determining step the 1,2-H migration concertedly occurs with the deprotonation of O2-H hydroxyl group, which is in nature different from the stepwise mechanism proposed in the early literature. The present results provide a molecule-level understanding for the isomerization mechanism of glucose to fructose catalyzed by chromium chlorides in imidazolium chlorine ILs.

  17. Refractive index measurement of imidazolium based ionic liquids in the Vis-NIR

    Science.gov (United States)

    Arosa, Yago; Rodríguez Fernández, Carlos Damián; López Lago, Elena; Amigo, Alfredo; Varela, Luis Miguel; Cabeza, Oscar; de la Fuente, Raúl

    2017-11-01

    In this paper spectrally resolved white light interferometry is applied for measuring the refractive index of different ionic liquids over a wide spectral band from 400 to 1000 nm. The measuring device is compound by a Michelson interferometer whose output is analyzed by means of two spectrometers. The first one is a homemade prism spectrometer which provides the interferogram produced by the sample over a wide continuum spectrum. The second one is a commercial diffraction grating spectrometer used to make high precision measurements of the displacement between the Michelson mirrors by interferometry. Both instruments combined allow the retrieval of the refractive index of the sample over a wide visible-near infrared continuum spectrum with deviations on the fourth decimal. A group of 14 different ionic liquids based on the 1-alkyl-3-methylimidazolium cation have been studied through this technique. The measured refractive index of the ionic liquids is used to calculate their electronic polarizability. This makes possible to gain insight into the microscopic behavior of the compounds. To give a better picture, the liquids have been classified in four groups and their refractive indices and polarizabilities are compared in order to find correlations between these magnitudes and the structure of the liquids.

  18. Development of biosensors containing laccase and imidazolium bis(trifluoromethylsulfonyl)imide ionic liquid for the determination of rutin

    Energy Technology Data Exchange (ETDEWEB)

    Franzoi, Ana Cristina [Departamento de Quimica, Laboratorio de Biossensores, Universidade Federal de Santa Catarina, 88040-970 Florianopolis, SC (Brazil); Migowski, Pedro; Dupont, Jairton [Departamento de Quimica Organica, Laboratorio de Catalise Molecular, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, RS (Brazil); Cruz Vieira, Iolanda, E-mail: iolanda@qmc.ufsc.br [Departamento de Quimica, Laboratorio de Biossensores, Universidade Federal de Santa Catarina, 88040-970 Florianopolis, SC (Brazil)

    2009-04-20

    Biosensors based on hydrophobic ionic liquids (ILs) derived from the bis(trifluoromethylsulfonyl)imide [(CF{sub 3}SO{sub 2}){sub 2}N{sup -} = Tf{sub 2}N{sup -}] anion associated with three different imidazolium cations: 1-butyl-3-methylimidazolium (BMI.Tf{sub 2}N), 1-decyl-3-methylimidazolium (DMI.Tf{sub 2}N) and 1-tetradecyl-3-methylimidazolium (TDMI.Tf{sub 2}N), along with laccase from Aspergillus oryzae, were constructed and optimized for determination of rutin. The laccase catalyzes the oxidation of rutin to the corresponding o-quinone, which is electrochemically reduced back to rutin. The best performance was obtained with 50:20:15:15% (w/w/w/w) as the graphite powder:laccase:Nujol:ILs composition in 0.1 mol L{sup -1} acetate buffer solution (pH 5.0). The parameters for the square-wave voltammetry experiments and scanning electron microscopy images of the biosensors were studied. Under the selected conditions, the cathodic peak current increased linearly in the rutin concentration ranges of 4.77 x 10{sup -6} to 4.62 x 10{sup -5} mol L{sup -1}, 5.84 x 10{sup -6} to 5.36 x 10{sup -5} mol L{sup -1} and 5.84 x 10{sup -6} to 5.36 x 10{sup -5} mol L{sup -1} using the (I) BMI.Tf{sub 2}N-laccase, (II) DMI.Tf{sub 2}N-laccase and (III) TDMI.Tf{sub 2}N-laccase, respectively. The rutin contents of commercial samples of pharmaceuticals were successfully determined by the biosensors and the results compared well with those obtained using the official method. The studies on rutin recovery from these samples gave values of 96.9-104.6%.

  19. Ionic crosslinking of imidazolium functionalized poly(aryl ether ketone) by sulfonated poly(ether ether ketone) for anion exchange membranes.

    Science.gov (United States)

    Xu, Yixin; Ye, Niya; Zhang, Dengji; Yang, Jingshuai; He, Ronghuan

    2017-07-01

    Two N3-substituted imidazoles 1,2-dimethylimidazole and 1-butyl-2-methylimidazole were chosen to functionalize poly(aryl ether ketone), respectively. The generated imidazolium cations could electrostatically react with sulfonate ions of the sulfonated poly(ether ether ketone) forming the ionic crosslinking structure of the membranes. The changes in crosslinking degree and the alkyl chain-length on N3 site of the imidazoliums could highly affect the properties of the anion exchange membranes (AEMs). The AEMs functionalized by 1-butyl-2-methylimidazole exhibited superior properties compared to those functionalized by 1,2-dimethylimidazole according to the tolerance tests of the AEMs towards hot alkaline solutions. After exposed to 1M KOH at 80°C for 200h, the 1-butyl-2-methylimidazole modified AEMs maintained the ion exchange capacity of above 85%, the conductivity of about 70%, and the tensile stress at break of around 80%, respectively. The hydrophile-lipophile balance of the polymer membranes was calculated and proposed to better understand the correlation between structures and properties of the AEMs. The degradation of the imidazolium functional groups of the AEMs under the attack of hydroxide ions was evidenced by FT-IR analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

  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. Probing electron density of H-bonding between cation-anion of imidazolium-based ionic liquids with different anions by vibrational spectroscopy.

    Science.gov (United States)

    Gao, Yan; Zhang, Liqun; Wang, Yong; Li, Haoran

    2010-03-04

    Attenuated total reflection infrared spectroscopy and density functional theory calculation have been employed to study the spectral properties of imidazolium-based ionic liquids (ILs) with different anions. ILs based on 1-butyl-3-methylimidazolium cation with different anions, OH(-), CF(3)CO(2)(-), HSO(4)(-), H(2)PO(4)(-), Cl(-), PF(6)(-), and BF(4)(-), are investigated in the present work. It has been shown that the C(2)-H stretching vibration of the imidazolium ring is closely related to the electron density of H-bonding between the two closest cations and anions for pure ILs. The electron density of H-bonding between cation and anion with different anions decreases in the order [OH](-) > [H(2)PO(4)](-) > [HSO(4)](-) > [CF(3)CO(2)](-) > [Cl](-) > [BF(4)](-) > [PF(6)](-). For aqueous ILs, with increasing water content, the aromatic C-H stretching vibration of the imidazolium cation showed systematic blue-shifts. Especially for BmimOH, the nu(C(2))(-H) undergoes a drastic blue-shift by 58 cm(-1), suggesting that the formation of the strong hydrogen bonds O-H...O may greatly weaken the electron density of H-bonding between the cation and anion of ILs.

  2. Dependency of Anion and Chain Length of Imidazolium Based Ionic Liquid on Micellization of the Block Copolymer F127 in Aqueous Solution: An Experimental Deep Insight

    Directory of Open Access Journals (Sweden)

    Jignesh Lunagariya

    2017-07-01

    Full Text Available The non-ionic triblock copolymer, Pluronic® F127, has been selected to observe its interaction with ionic liquids (ILs in aqueous solutions by using DLS, surface tension, and viscosity measurements. The Critical Micelle Concentration (CMC of F127 increased with the addition of ILs, which appeared logical since it increases the solubility of PPO (and PEO moiety, making it behaves more like a hydrophilic block copolymer that is micellized at a higher copolymer concentration. The results from DLS data showed good agreement with those obtained from the surface tension measurements. Upon the addition of ILs, the tendency in micellar size reduction was demonstrated by viscosity results, and therefore, intrinsic viscosity decreased compared to pure F127 in aqueous solution. The results were discussed as a function of alkyl chain length and anions of imidazolium based ILs.

  3. 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.

  4. Electrochemical characterisation of a lithium-ion battery electrolyte based on mixtures of carbonates with a ferrocene-functionalised imidazolium electroactive ionic liquid.

    Science.gov (United States)

    Forgie, John C; El Khakani, Soumia; MacNeil, Dean D; Rochefort, Dominic

    2013-05-28

    Electrolytic solutions of lithium-ion batteries can be modified with additives to improve their stability and safety. Electroactive molecules can be used as such additives to act as an electron (redox) shuttle between the two electrodes to prevent overcharging. The electroactive ionic liquid, 1-ferrocenylmethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide (TFSI), was synthesised and its electrochemical properties were investigated when diluted with ethylene carbonate-diethyl carbonate solvent at various concentrations. Cyclic voltammetry data were gathered to determine the redox potential, diffusion coefficient and heterogeneous rate constants of the electroactive imidazolium TFSI ionic liquid in the carbonate solution. The properties of this molecule as an additive in lithium battery electrolytes were studied in standard coin cells with a metallic Li anode and a Li4Ti5O12 cathode.

  5. Transport of imidazolium-based ionic liquids with different anion/cation species in sand/soil columns.

    Science.gov (United States)

    Dong, Zhiqiang; Wei, Li; Xu, Suwei; Sun, Jingwei; Shi, Xinyi; Qiu, Yuping

    2018-01-01

    Ionic liquids (ILs) have been widely used as environmentally friendly solvents to replace volatile organic solvents in the chemistry industries. They have a high water solubility and potential risk to organisms in the soil-water environment. At present, most studies focused on the batch sorption of ILs in soil and neglected the investigation of IL transports in soil, which results in a lack of understanding of the structure-dependent mobility of ILs in the environment. Laboratory-scale sand/soil column experiments were performed to study the transport of imidazolium-based ILs, such as [C4mim][OTF], [C4mim][TOS], [C4mim][MeSO3], [C4mim][BF4], [C2mim][BF4], and [C6mim][BF4] including different counteranions and alkyl chain lengths of IL cations. Batch experiments were also carried out to compare the difference of sorption distribution coefficient (Kd) between the batch and column experiments. A one-dimensional convective-dispersive model using CXTFIT code was created based on the measured breakthrough curves (BTCs) to estimate the column transport parameters. For the anion, [BF4-], the Kd of ILs in both batch and column experiments increased with increasing alkyl chain lengths of the IL cation. In batch tests, counteranions showed no influence on the Kd of [C4mim][OTF], [C4mim][TOS], [C4mim][MeSO3], [C4mim][BF4], [C2mim][BF4], and [C6mim][BF4]. However, in column tests, the BTCs of 1-butyl-3-methylimidazolium-based ILs were anion dependent as evidenced by the change of retardation factor (R) for different counteranions. Furthermore, the effects of transport distance (11cm, 15cm, 19cm, and 24cm) on the mobility of ILs were estimated. The longer distances signified an increase in the contact time and more binding sites for ILs and therefore, the smoother shapes of BTCs in column experiments. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Solubilities of carbon dioxide and oxygen in the ionic liquids methyl trioctyl ammonium bis(trifluoromethylsulfonyl)imide, 1-butyl-3-methyl imidazolium bis(trifluoromethylsulfonyl)imide, and 1-butyl-3-methyl imidazolium methyl sulfate.

    Science.gov (United States)

    Bahadur, Indra; Osman, Khalid; Coquelet, Christophe; Naidoo, Paramespri; Ramjugernath, Deresh

    2015-01-29

    Ionic liquids (ILs) are being considered as solvents for gas absorption processes as they have the potential, in general, for improved efficiency of gas separations, as well as lower capital and operating costs compared to current commercial processes. In this study the solvent properties of ILs are investigated for use in the absorption of carbon dioxide (CO2) and oxygen (O2). The absorption of these gases in ILs was measured in the temperature range 303.15-333.15 K and at pressures up to 1.5 MPa by gravimetric analysis. The ILs used were methyl trioctyl ammonium bis (trifluoromethylsulfonyl) imide ([MOA][Tf2N]), 1-butyl-3-methyl imidazolium bis (trifluoromethylsulfonyl) imide ([BMIM][Tf2N]), and 1-butyl-3-methyl imidazolium methyl sulfate ([BMIM][MeSO4]). The measurement technique employed in this study is fast and accurate, and requires small quantities of solvent. The results indicated that absorption of both gases increased with a decrease in operating temperature and an increase in pressure. [MOA][Tf2N] had the highest CO2 and O2 solubility. [BMIM][Tf2N] was determined to have the highest selectivity for CO2 absorption. [BMIM][MeSO4] achieved the lowest CO2 absorption with a moderate O2 absorption, revealing this IL to be the least desirable for CO2 and O2 absorption. Calculation of Henry's law constants for all systems confirmed the deductions made from absorption data analysis. Calculation of enthalpy and entropy of absorption for each system revealed CO2 absorption in [MOA][Tf2N] to be the least sensitive to temperature increases. The absorption data was modeled using the generic Redlich-Kwong cubic equation of state (RK-EOS) coupled with a group contribution method.

  7. Epitope mapping of imidazolium cations in ionic liquid-protein interactions unveils the balance between hydrophobicity and electrostatics towards protein destabilisation.

    Science.gov (United States)

    Silva, Micael; Figueiredo, Angelo Miguel; Cabrita, Eurico J

    2014-11-14

    We investigated imidazolium-based ionic liquid (IL) interactions with human serum albumin (HSA) to discern the level of cation interactions towards protein stability. STD-NMR spectroscopy was used to observe the imidazolium IL protons involved in direct binding and to identify the interactions responsible for changes in Tm as accessed by differential scanning calorimetry (DSC). Cations influence protein stability less than anions but still significantly. It was found that longer alkyl side chains of imidazolium-based ILs (more hydrophobic) are associated with a higher destabilisation effect on HSA than short-alkyl groups (less hydrophobic). The reason for such destabilisation lies on the increased surface contact area of the cation with the protein, particularly on the hydrophobic contacts promoted by the terminus of the alkyl chain. The relevance of the hydrophobic contacts is clearly demonstrated by the introduction of a polar moiety in the alkyl chain: a methoxy or alcohol group. Such structural modification reduces the degree of hydrophobic contacts with HSA explaining the lesser extent of protein destabilisation when compared to longer alkyl side chain groups: above [C2mim](+). Competition STD-NMR experiments using [C2mim](+), [C4mim](+) and [C2OHmim](+) also validate the importance of the hydrophobic interactions. The combined effect of cation and anion interactions was explored using (35)Cl NMR. Such experiments show that the nature of the cation has no influence on the anion-protein contacts, still the nature of the anion modulates the cation-protein interaction. Herein we propose that more destabilising anions are likely to be a result of a partial contribution from the cation as a direct consequence of the different levels of interaction (cation-anion pair and cation-protein).

  8. Toxicity of two imidazolium ionic liquids, [bmim][BF4] and [omim][BF4], to standard aquatic test organisms: Role of acetone in the induced toxicity.

    Science.gov (United States)

    Tsarpali, Vasiliki; Dailianis, Stefanos

    2015-07-01

    The main goal of this study was to investigate the toxicity of the imidazolium-based ionic liquids (ILs), [bmim][BF4] (1-butyl-3-methylimidazolium tetrafluoroborate) and [omim][BF4] (1-octyl-3-methylimidazolium tetrafluoroborate), in battery of standard aquatic toxicity test organisms. Specifically, exposure of the algae Scenedesmus rubescens, crustaceans Thamnocephalus platyurus and Artemia franciscana, rotifers Brachionus calyciflorus and Brachionus plicatilis and bivalve Mytilus galloprovincialis to different concentrations of [bmim][BF4], [omim][BF4] and/or a binary mixture of [bmim][BF4]-[omim][BF4] (1:1) with or without acetone (carrier solvent), revealed that solvent can differentially mediate ILs' toxic profile. Acetone's ability to differentially affect ILs' cation's alkyl chain length, as well as the hydrolysis of [BF4(-)] anions was evident. Given that the toxic potency of the tested ILs seemed to be equal or even higher (in some cases) than those of conventional organic solvents, the present study revealed that the characterization of imidazolium-based ILs as "green solvents" should not be generalized, at least in case of their natural occurrence in mixtures with organic solvents, such as acetone. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Imidazolium ionic liquid induced one-step synthesis of -Fe2O3 nanorods and nanorod assemblies for lithium-ion battery

    Directory of Open Access Journals (Sweden)

    Shuting Xie

    2016-12-01

    Full Text Available α-Fe2O3 nanorods and nanorod assemblies are prepared via a facile one-step method with the assistance of imidazolium-based ionic liquid. The aspect ratio of synthesized nanorods is determined by the alkyl chain length of [Cnmim]+. The inter-molecular π−π interaction and intra-molecular dipole-dipole interaction among imidazole rings of [C4mim]+[PhCOO]− play critical roles in both nucleation and assembly processes of α-Fe2O3 nanorods. The α-Fe2O3 nanorod assemblies show an excellent performance in lithium-ion batteries with a reversible capacity of 1007.3 mA h g−1 at the rate of 500 mA g−1 after 150 cycles.

  10. New Eco-Friendly 1-Alkyl-3-(4-phenoxybutyl Imidazolium-Based Ionic Liquids Derivatives: A Green Ultrasound-Assisted Synthesis, Characterization, Antibacterial Activity and POM Analyses

    Directory of Open Access Journals (Sweden)

    Mouslim Messali

    2014-08-01

    Full Text Available In view of the emerging importance of the ILs as “green” materials with wide applications and our general interests in green processes, a series of a twenty five new 1-alkyl-3-(4-phenoxybutyl imidazolium-based ionic liquids (ILs derivatives is synthesized using a facile and green ultrasound-assisted procedure. Their structures were characterized by FT-IR, 1H-NMR, 13C-NMR, 11B, 19F, 31P, and mass spectrometry. Antimicrobial screens of some selected ILs were conducted against a panel of Gram-positive and Gram-negative bacteria. The antimicrobial activity of each compound was measured by determination of the minimal inhibitory concentration (MIC yielding very interesting and promising results. Their antibacterial activities are reported, and, on the basis of the experimental and virtual POM screening data available, attempt is also made to elucidate the structure activity relationship.

  11. Comparison of different imidazolium supported ionic liquid polymeric phases with strong anion-exchange character for the extraction of acidic pharmaceuticals from complex environmental samples.

    Science.gov (United States)

    Bratkowska, Dominika; Fontanals, Núria; Ronka, Sylwia; Trochimczuk, Andrzej W; Borrull, Francesc; Marcé, Rosa M

    2012-08-01

    Two imidazolium supported ionic liquid phases (SILPs) containing different anions, trifluoromethanesulphonate [CF(3)SO(3)(-)], and tetrafluoroborate [BF(4)(-)], were synthesized and evaluated as solid-phase extraction sorbents for extracting acidic pharmaceuticals from aqueous samples under strong anion-exchange conditions, which include an effective cleanup of the sample. The best SILP material [MI(+)][CF(3)SO(3)(-) ] was selected and successfully applied to the determination of acidic pharmaceuticals in different types of water samples (river water and effluent wastewater). The results were then compared to the previously synthesized SILP material based on [MI(+)][CF(3)COO(-)] and the commercially available Oasis MAX sorbent. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Ionic iron(III) complexes of bis(phenol)-functionalized imidazolium cations: synthesis, structures and catalysis for aryl Grignard cross-coupling of alkyl halides.

    Science.gov (United States)

    Deng, Hai-ning; Xing, Ya-lin; Xia, Cong-liang; Sun, Hong-mei; Shen, Qi; Zhang, Yong

    2012-10-14

    A series of bis(phenol)-functionalized imidazolium salts, 1,3-bis(4,6-di-R(1)-2-hydroxybenzyl)-2-R(2)-4,5-di-R(3)-imidazolium chlorides H(3)L(n)Cl (R(1) = (t)Bu, R(2) = R(3) = H, H(3)L(1)Cl, 1; R(1) = CH(3), R(2) = R(3) = H, H(3)L(2)Cl, 2; R(1) = (t)Bu, R(2) = H, R(3) = Cl, H(3)L(3)Cl, 3; R(1) = (t)Bu, R(2) = CH(3), R(3) = H, H(3)L(4)Cl, 4), were used to produce a novel series of ionic iron(III) complexes [H(3)L(n)][FeX(4)] (n = 1, X = Cl, 5; n = 2, X = Cl, 6; n = 3, X = Cl, 7; n = 4, X = Cl, 8; n = 1, X = Br, 9; n = 3, X = Br, 10). All of the complexes were characterized by Raman spectroscopy and electrospray ionization mass spectrometry. Elemental analysis and X-ray crystallography were also used. All of the complexes were non-hygroscopic and air-stable, with five of them existing as solids (5, 7-10) and one as an oil (6) at room temperature. A preliminary catalytic study on the cross-coupling reactions of aryl Grignard reagents with primary and secondary alkyl halides bearing β-hydrogens, revealed that all of the ionic iron(III) complexes exhibited good to excellent catalytic activity. Complexes 5, 6 and 8 exhibited optimal activity, whereas 7, 9 and 10 showed only moderate activity. Furthermore, by simply decanting the cross-coupling product in the ether layer, complexes 5 and 6 could be reused in at least seven successive runs without significant loss in catalytic activity.

  13. High resolution of racemic phenylalanine with dication imidazolium-based chiral ionic liquids in a solid-liquid two-phase system.

    Science.gov (United States)

    Huang, Xiaoxia; Wu, Haoran; Wang, Zhixia; Luo, Yingjie; Song, Hang

    2017-01-06

    A novel solid-liquid two-phase system was developed for the chiral separation of racemic phenylalanine with new dication imidazolium-based chiral ionic liquids. Preliminary experiments showed distinct enantioselectivity in amino acid extraction with the novel solid-liquid two-phase system, more L-enantiomer of amino acid cooperatively interacted with ionic liquids and copper ions to be the solid phase. Various factors, including the alkyl chain length of cations of ionic liquids, the amount of copper acetate, the ratio of n(ILs)/n(Cu2+), the amount of water and racemic phenylalanine, the resolution time together with the resolution temperature, were systematically investigated for their influence on resolution efficiency. The results showed that, under a certain condition, the enantiomeric excess value and the yield of phenylalanine in liquid phase (mainly containing D-enantiomer) were 67.8% and 96.5%, the enantiomeric excess value and the yield of phenylalanine in solid phase (mainly containing L-enantiomer) were 99.2% and 85.2%. Finally, 2D NMR technology, infrared spectroscopy and molecular simulation method were used to study the interaction mechanism. The results indicated that L-enantiomer of phenylalanine interacts more strongly with chiral ILs and Cu2+. The novel system has characteristics of free-organic solvent, simple operation, fast separation process and very high resolution efficiency for racemic phenylalanine. This work could provide a new and alternative resolution approach for other chiral separations. Copyright © 2016. Published by Elsevier B.V.

  14. Imidazolium-based anion exchange membranes for alkaline anion fuel cells: (2) elucidation of the ionic structure and its impact on conducting properties.

    Science.gov (United States)

    Yoshimura, Kimio; Zhao, Yue; Hasegawa, Shin; Hiroki, Akihiro; Kishiyama, Yoshihiro; Shishitani, Hideyuki; Yamaguchi, Susumu; Tanaka, Hirohisa; Koizumi, Satoshi; Appavou, Marie-Sousai; Radulescu, Aurel; Richter, Dieter; Maekawa, Yasunari

    2017-11-22

    In our previous study (Soft Matter, 2016, 12, 1567), the relationship between the morphology and properties of graft-type imidazolium-based anion exchange membranes (AEMs) was revealed, in that the semi-crystalline features of the polymer matrix maintain its mechanical properties and the formation of interconnected hydrophilic domains promotes the membrane conductivity. Here, we report a novel ionic structure of the same graft-type AEMs with different grafting degrees, analyzed using a small-angle X-ray scattering method under different relative humidity (RH) conditions. The characteristic "ionomer peak" with a corresponding correlation distance of approximately 1.0 nm was observed at RH ionic clusters, but close to the Bjerrum length of water. Since the representative number of water molecules per cation, nw, was small, we proposed that dissociated ion-pairs are distributed in the hydrophilic domains (ion-channels). At RH < 80%, ion-channels are disconnected, however in liquid water, they are well-connected as evidenced by the sharp increase in nw. The disconnected ion-channels even under relatively high RH conditions should be a substantial factor for the low power generation efficiency of AEM-type fuel cells.

  15. 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.

  16. Hydroxyl-functionalized 1-(2-hydroxyethyl)-3-methyl imidazolium ionic liquids: thermodynamic and structural properties using molecular dynamics simulations and ab initio calculations.

    Science.gov (United States)

    Fakhraee, Mostafa; Zandkarimi, Borna; Salari, Hadi; Gholami, Mohammad Reza

    2014-12-11

    The influences of hydroxyl functional group (-OH) on the thermodynamic and structural properties of ionic liquids (ILs) composed of 1-(2-Hydroxyethyl)-3-methyl imidazolium ([C2OHmim](+)) cation and the six different conventional anions, including [Cl](-), [NO3](-), [BF4](-), [PF6](-), [TfO](-), and [Tf2N](-) have been extensively investigated using classical molecular dynamics (MD) simulations combined with ab initio calculations over a wide range of temperature (298-550 K). The volumetric thermodynamic properties, enthalpy of vaporization, cohesive energy density, Hildebrand solubility parameter, and heat capacity at constant pressure were estimated at desired temperature. The simulated densities were in good agreement with the experimental data with a slight overestimation. The interionic interaction of selected ILs was also computed using both the MD simulations and ab initio calculations. It was found that the highest association of cation and anion is attributed to [C2OHmim][Cl] followed by [C2OHmim][NO3], and [C2OHmim][Tf2N] with the bulkiest anion has the weakest interionic interaction among chosen ILs. The similar trend of interactions energies was nearly observed from cohesive energy density results. Additional structural details were comprehensively yielded by calculating radial distribution functions (RDFs) and spatial distribution function (SDFs) at 358 K. The most stable configurations of isolated and dimer ion pairs of these ILs were in excellent consistency with RDFs and SDFs results. Significant changes in arrangement of anions around the [C2OHmim](+) cation in comparison with conventional imidazolium-based ILs can be inferred from the MD simulations and ab initio results. Also, microscopic structural properties disclosed that the most strong cation-cation interaction is ascribed to the hydroxyl-functionalized ILs composed of bulkier anions, whereas ILs incorporating [Cl](-) and [NO3](-) anions are mainly involved in cation-anion interactions. The

  17. Effect of water on the transport properties of protic and aprotic imidazolium ionic liquids - an analysis of self-diffusivity, conductivity, and proton exchange mechanism.

    Science.gov (United States)

    Yaghini, N; Nordstierna, L; Martinelli, A

    2014-05-28

    In this paper we report on the transport properties of protic and aprotic ionic liquids of the imidazolium cation (C2C1Im(+) or C2HIm(+)) and the TFSI(-) or TfO(-) anion as a function of added water. We observe that the self-diffusion coefficient of the ionic species increases upon addition of water, and that the cation diffuses faster than the anion in the entire water concentration range investigated. We also observe that the overall increase of anionic and cationic diffusion coefficients is significant for C2HImTfO while it is rather weak for C2C1ImTFSI, the former being more hydrophilic. Moreover, the difference between cationic and anionic self-diffusivity specifically depends on the structure of the ionic liquid's ions. The degree of ion-ion association has been investigated by comparing the molar conductivity obtained by impedance measurements with the molar conductivity calculated from NMR data using the Nernst-Einstein equation. Our data indicate that the ions are partly dissociated (Λimp/ΛNMR in the range 0.45-0.75) but also that the degree of association decreases in the order C2HImTfO > C2HImTFSI ≈ C2C1ImTfO > C2C1ImTFSI. From these results, it seems that water finds different sites of interaction in the protic and aprotic ionic liquids, with a strong preference for hydrogen bonding to the -NH group (when available) and a stronger affinity to the TfO anion as compared to the TFSI. For the protic ionic liquids, the analysis of (1)H NMR chemical shifts (upon addition of H2O and D2O, respectively) indicates a water-cation interaction of hydrogen bonding nature. In addition, we could probe proton exchange between the -NH group and deuterated water for the protic cation, which occurs at a significantly faster rate if associated with the TfO anion as compared to the TFSI.

  18. Anion and cation effects on the size control of Au nanoparticles prepared by sputter deposition in imidazolium-based ionic liquids.

    Science.gov (United States)

    Hatakeyama, Yoshikiyo; Judai, Ken; Onishi, Kei; Takahashi, Satoshi; Kimura, Satoshi; Nishikawa, Keiko

    2016-01-28

    The sputter deposition of metals in an ionic liquid (IL) capture medium is a simple and elegant method for preparing nanoparticles without any chemical reaction. Although there have been some reports on the size determination factors for Au nanoparticles (AuNPs) prepared using this method, the effects with respect to the type of IL used have not been clearly elucidated. This is because there are some complicating factors, some of which have been revealed by our previous systematic studies. In the present study, we prepare AuNPs in nine types of imidazolium-based IL to examine the size determination effects of the type of anion involved, the length of the alkyl chain of the cation, and the preparation temperature for each IL, while keeping other factors constant. For most of the capture media ILs, the sizes of the AuNPs increase with an increase in temperature. The AuNPs prepared in ILs containing different types of anions exhibit distinctly different particle sizes and temperature dependences. Conversely, the alkyl chain is regarded as a secondary stabilizer that works only at higher preparation temperatures. We conclude that the sizes of AuNPs prepared by this method may be determined by the competition between the collision frequency of the ejected Au atoms and the stabilizing capability of the anions that form the first coordination shell around the AuNPs. The AuNP sizes are closely related to the volume of anions.

  19. Photoluminescent Honeycomb Structures from Polyoxometalates and an Imidazolium-Based Ionic Liquid Bearing a π-Conjugated Moiety and a Branched Aliphatic Chain.

    Science.gov (United States)

    Zhang, Geping; Zhu, Hongxia; Chen, Mengjun; Li, Hongguang; Yuan, Ye; Ma, Tiantai; Hao, Jingcheng

    2017-05-29

    Honeycomb-structured films represent an intriguing class of two-dimensional porous materials. Specifically, polyoxometalate (POM) macroanions can be introduced into these films by complexing with oppositely charged, double-tailed surfactants. Here highly-ordered honeycomb structures are reported that can be constructed by the complexes between POMs and a room temperature ionic liquid (IL1) having an imidazolium moiety in the middle and a naphthyl unit and a branched aliphatic chain at the ends. The complexes can be produced through phase transfer between an aqueous solution of POMs (typically {Mo72 Fe30 }) and a CS2 (or chloroform) solution of IL1. Based on the intrinsic properties of {Mo72 Fe30 } and the functional groups of the IL1, the honeycomb structures show multiple functions with bright photoluminescence and rich electrochemical properties. This work shows that by simply engineering the organic ligands involved in the POM-based inorganic-organic complexes, supramolecular structures with improved properties and wide applications can be obtained. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. X-ray Reflectivity Study of the Interaction of an Imidazolium-Based Ionic Liquid with a Soft Supported Lipid Membrane.

    Science.gov (United States)

    Bhattacharya, G; Giri, R P; Saxena, H; Agrawal, V V; Gupta, A; Mukhopadhyay, M K; Ghosh, S K

    2017-02-07

    Ionic liquids (ILs) are important for their antimicrobial activity and are found to be toxic to some microorganisms. To shed light on the mechanism of their activities, the interaction of an imidazolium-based IL 1-butyl-3-methylimidazolium tetrfluoroborate ([BMIM][BF4]) with E. coli bacteria and cell-membrane-mimicking lipid mono- and bilayers has been studied. The survival of the bacteria and corresponding growth inhibition are observed to be functions of the concentration of the IL. The IL alters the pressure-area isotherm of the monolayer formed at an air-water interface by the 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid. The in-plane elasticity of the lipid layer is reduced as a consequence of the insertion of this IL. The X-ray reflectivity study from a polymer-supported lipid bilayer shows strong perturbation in the self-assembled structure of the bilayer due to the interaction. As a consequence, there is a considerable decrease in bilayer thickness and a corresponding increase in electron density. These results, however, depend on the chain configurations of the lipid molecules.

  1. Complementary Molecular Dynamics and X-ray Reflectivity Study of an Imidazolium-Based Ionic Liquid at a Neutral Sapphire Interface.

    Science.gov (United States)

    Brkljača, Zlatko; Klimczak, Michael; Miličević, Zoran; Weisser, Matthias; Taccardi, Nicola; Wasserscheid, Peter; Smith, David M; Magerl, Andreas; Smith, Ana-Sunčana

    2015-02-05

    Understanding the molecular-level behavior of ionic liquids (ILs) at IL-solid interfaces is of fundamental importance with respect to their application in, for example, electrochemical systems and electronic devices. Using a model system, consisting of an imidazolium-based IL ([C2Mim][NTf2]) in contact with a sapphire substrate, we have approached this problem using a complementary combination of high-resolution X-ray reflectivity measurements and atomistic molecular dynamics (MD) simulations. Our strategy enabled us to compare experimental and theoretically calculated reflectivities in a direct manner, thereby critically assessing the applicability of several force-field variants. On the other hand, using the best-matching MD description, we are able to describe the nature of the model IL-solid interface in appreciable detail. More specifically, we find that characteristic interactions between the surface hydroxyl groups and donor and acceptor sites on the IL constituents have a dominant role in inducing a multidimensional layering profile of the cations and anions.

  2. Biomedical Exploitation of Chitin and Chitosan via Mechano-Chemical Disassembly, Electrospinning, Dissolution in Imidazolium Ionic Liquids, and Supercritical Drying

    Directory of Open Access Journals (Sweden)

    Riccardo A. A. Muzzarelli

    2011-09-01

    Full Text Available Recently developed technology permits to optimize simultaneously surface area, porosity, density, rigidity and surface morphology of chitin-derived materials of biomedical interest. Safe and ecofriendly disassembly of chitin has superseded the dangerous acid hydrolysis and provides higher yields and scaling-up possibilities: the chitosan nanofibrils are finding applications in reinforced bone scaffolds and composite dressings for dermal wounds. Electrospun chitosan nanofibers, in the form of biocompatible thin mats and non-wovens, are being actively studied: composites of gelatin + chitosan + polyurethane have been proposed for cardiac valves and for nerve conduits; fibers are also manufactured from electrospun particles that self-assemble during subsequent freeze-drying. Ionic liquids (salts of alkylated imidazolium are suitable as non-aqueous solvents that permit desirable reactions to occur for drug delivery purposes. Gel drying with supercritical CO2 leads to structures most similar to the extracellular matrix, even when the chitosan is crosslinked, or in combination with metal oxides of interest in orthopedics.

  3. Imidazolium fumarate

    Directory of Open Access Journals (Sweden)

    Rodolfo Moreno-Fuquen

    2009-11-01

    Full Text Available In the title compound, C3H5N2+·C4H3O4−, the dihedral angle between the imidazolium ring and the plane formed by the fumarate anion is 80.98 (6°. In the crystal structure, intermolecular O—H...O and N—H...O hydrogen bonds form extended chains along [100] and [01overline{1}], creating a two-dimensional network.

  4. Effect of SO2 on the transport properties of an imidazolium ionic liquid and its lithium solution.

    Science.gov (United States)

    Monteiro, Marcelo J; Ando, Rômulo A; Siqueira, Leonardo J A; Camilo, Fernanda F; Santos, Paulo S; Ribeiro, Mauro C C; Torresi, Roberto M

    2011-08-11

    Transport coefficients have been measured as a function of the concentration of sulfur dioxide, SO(2), dissolved in 1-butyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide, [BMMI][Tf(2)N], as well as in its lithium salt solution, Li[Tf(2)N]. The SO(2) reduces viscosity and density and increases conductivity and diffusion coefficients in both the neat [BMMI][Tf(2)N] and the [BMMI][Tf(2)N]-Li[Tf(2)N] solution. The conductivity enhancement is not assigned to a simple viscosity effect; the weakening of ionic interactions upon SO(2) addition also plays a role. Microscopic details of the SO(2) effect were unraveled using Raman spectroscopy and molecular dynamics (MD) simulations. The Raman spectra suggest that the Li(+)-[Tf(2)N] interaction is barely affected by SO(2), and the SO(2)-[Tf(2)N] interaction is weaker than previously observed in an investigation of an ionic liquid containing the bromide anion. Transport coefficients calculated by MD simulations show the same trend as the experimental data with respect to SO(2) content. The MD simulations provide structural information on SO(2) molecules around [Tf(2)N], in particular the interaction of the sulfur atom of SO(2) with oxygen and fluorine atoms of the anion. The SO(2)-[BMMI] interaction is also important because the [BMMI] cations with above-average mobility have a larger number of nearest-neighbor SO(2) molecules. © 2011 American Chemical Society

  5. Leaching performance of imidazolium based ionic liquids in the presence of hydrogen peroxide for recovery of metals from brass waste

    Energy Technology Data Exchange (ETDEWEB)

    Kelicarslan, A.; Saridede, M. N.

    2016-05-01

    The application of ionic liquids (ILs), 1-methylimidazolium hydrogen sulfate (HmimHSO{sub 4}), 1-ethyl-3-methylimidazolium hydrogen sulfate (EmimHSO{sub 4}) and 1-butyl-3-methylimidazolium chloride (BmimCl) as leaching agents was investigated in the leaching of copper and zinc from brass waste in the presence of an oxidant, hydrogen peroxide (H{sub 2}O{sub 2}). Factors that affect copper and zinc dissolution rates such as ionic liquid concentration, time and temperature were investigated. The results indicated that zinc was dissolved in leach solutions with EmimHSO{sub 4} and HmimHSO{sub 4}, completely. Temperature had no considerable influence on copper dissolution rate whilst the rate increased with decreasing IL concentration. In the EmimHSO{sub 4} system, higher copper recoveries were achieved with 40% and 60% IL concentrations compared with IL concentrations of 20% and 80% at 40 degree centigrade leaching temperature. Copper dissolution rates decreased with EmimHSO{sub 4} concentration at 60 degree centigrade and 80 degree centigrade in the following order; 40%>20%>60%>80%. On the other hand the leaching system with BmimCl generally resulted in poor extractions of copper and zinc. (Author)

  6. Probing the Aggregation Behavior of Neat Imidazolium-Based Alkyl Sulfate (Alkyl = Ethyl, Butyl, Hexyl, and Octyl) Ionic Liquids through Time Resolved Florescence Anisotropy and NMR and Fluorescence Correlation Spectroscopy Study.

    Science.gov (United States)

    Majhi, Debashis; Pabbathi, Ashok; Sarkar, Moloy

    2016-01-14

    Aggregation behavior of a series of neat 1-ethyl 3-methylimidazolium alkyl sulfate (alkyl = ethyl, butyl, hexyl, and octyl) ionic liquids has been investigated through combined time-resolved fluorescence spectroscopy, 1-D and 2-D NMR spectroscopy, and fluorescence correlation spectroscopy (FCS). Interestingly, experimentally measured rotational relaxation times (τr) for ethyl, butyl, hexyl and octyl systems are measured to be 2.25, 1.64, 1.36, and 1.32 times higher than the estimated (from Stokes-Einstein-Debye theory) values for the same respective systems. This indicates that the emitting species is not the monomeric imidazolium moiety rather an associated species, and volume of the rotating fluorescing species decreases even though the length of the alkyl moiety on the anions is increased. The shift in the (1)H proton signal as well as a change in the width of the same signal upon dilution of the neat ionic liquids indicates that ionic liquids exist in the aggregated form. Further investigation through the 2D-ROESY experiment shows that interaction between imidazolium and sulfate is relatively stronger in the ethyl system than that of the longer octyl system. FCS measurements independently show that the hydrodynamic volume decreases with an increase in the anion chain length. The NMR and FCS results are consistent with the findings of the fluorescence anisotropy study.

  7. Anodic behavior of uranium in AlCl3-1-ethyl-3-methyl-imidazolium chloride ionic liquid

    Science.gov (United States)

    Jiang, Yidong; Luo, Lizhu; Wang, Shaofei; Bin, Ren; Zhang, Guikai; Wang, Xiaolin

    2018-01-01

    The oxidation state of metals unambiguously affects its anodic behavior in ionic liquid. We systematically investigated the anodic behavior of uranium with different surface oxidation states by electrochemical measurements, spectroscopic methods and surface analysis techniques. In the anodic process, metal uranium can be oxidized to U3+. The corresponding products accumulated on the metal/ILs interface will form a viscous layer. The anodic behavior of uranium is also strongly dependent upon the surface oxide states including thickness and homogeneity of the oxide film. With an increase in the thickness of oxide film, it will be breached at potentials in excess of a critical value. A uniform oxide on uranium surface can be breached evenly, and then the underlying metal starts to dissolve forming a viscous layer which can facilitate uniformly stripping of oxide, thus giving an oxide-free surface. Otherwise, a nonuniform oxide can result in a severe pitted surface with residue oxygen.

  8. Exploration of complexes of 18-crown-6 with three similarly substituted imidazolium, pyridinium and pyrrolidinium ionic liquids

    Science.gov (United States)

    Saha, Subhadeep; Roy, Mahendra Nath

    2017-09-01

    Supramolecular host-guest complexation with excellent comparison among three similarly substituted ionic liquids, namely, 1-butyl-3-methylimidazolium chloride, 1-butyl-4-methylpyridinium chloride and 1-butyl-1-methylpyrrolidinium chloride have been investigated with 18-crown-6 in acetonitrile medium by conductivity in a range of temperature to elucidate the stoichiometry of the complexes. The programmed mathematical study with the help of conductivity data provides association constants for the complexes, by which the thermodynamic properties have been evaluated for improved understanding about complexation. The molecular interactions have been explained and critically discussed with the help of FT-IR and 1H NMR spectroscopic studies, which illustrate H-bond and ion-dipolar attractions primarily exist in complexation.

  9. Imidazolium-Based Ionic Liquids as Efficient Reagents for the C-O Bond Cleavage of Lignin.

    Science.gov (United States)

    Thierry, Marina; Majira, Amel; Pégot, Bruce; Cezard, Laurent; Bourdreux, Flavien; Clément, Gilles; Perreau, François; Boutet-Mercey, Stéphanie; Diter, Patrick; Vo-Thanh, Giang; Lapierre, Catherine; Ducrot, Paul-Henri; Magnier, Emmanuel; Baumberger, Stéphanie; Cottyn, Betty

    2017-10-19

    The demethylation of lignin in ionic liquids (ILs) was investigated by using pure lignin model monomers and dimers together with dioxane-isolated lignins from poplar, miscanthus, and maize. Different methylimidazolium ILs were compared and the samples were treated with two different heating processes: microwave irradiation and conventional heating in a sealed tube. The conversion yield and influence of the treatment on the lignin structure were assessed by 31 P NMR spectroscopy, size-exclusion chromatography, and thioacidolysis. The acidic methylimidazolium IL [HMIM]Br was shown to be an effective combination of solvent and reagent for the demethylation and depolymerization of lignin. The relatively mild reaction conditions, the clean work-up, and the ability to reuse the IL makes the described procedure an attractive and new green method for the conversion of lignin to produce phenol-rich lignin oligomers. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Alkyl imidazolium ionic liquid based sweeping-micellar electrokinetic chromatography for simultaneous determination of seven tea catechins in human plasma.

    Science.gov (United States)

    El-Hady, Deia Abd; Albishri, Hassan M

    2014-10-15

    Determination of tea catechins in human plasma might provide a means of better evaluation of their benefits. The main difficulty in their analysis is the low catechins concentrations in plasma and their susceptible to oxidation during sample pretreatment. In the current work, a sweeping-micellar electrokinetic chromatography (sweeping-MEKC) by long alkyl chain ionic liquid was investigated for the simultaneous determination of seven principal naturally-occurring tea catechins in human plasma under acidic conditions after the intake of green tea beverage. The effects of type and concentration of three 1-tetradecyl-3-methylimidazolium ionic liquids, namely bromide, acetate and hydrogen sulfate salts were studied. The seven catechins were successfully separated within 5min by micellar running buffer of 5mmolL(-1) 1-tetradecyl-3-methylimidazolium bromide and 15mmolL(-1) phosphate buffer at pH 4.5 under optimal parameters of 50mbar injection for 150s, 10kV, 25°C and 200nm. To prevent the possibility of IL adsorption, an appropriate rinsing protocol was established. The method has analytical ranges from 0.5, 1, 0.5, 1, 2, 1 and 1 to 500ngmL(-1) for GC, C, EC, EGCG, GCG, ECG and EGC, respectively (r ranged from 0.995 to 0.999). The intraday precision and accuracy were 0.1-0.9% RSD (n=10) and 97-106% recovery, respectively. Limits of detections of analytes were ranged from 0.2 to 1.2ngmL(-1). The current sweeping-MEKC achieved sensitivity enhancement factor (SEF) up to 183-fold of analytes concentrations compared to other hitherto published CE reports that is suitable to find out the trace amounts of catechins in plasma. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. 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.

  12. Leaching performance of imidazolium based ionic liquids in the presence of hydrogen peroxide for recovery of metals from brass waste

    Directory of Open Access Journals (Sweden)

    Kilicarslan, Ayfer

    2016-03-01

    Full Text Available The application of ionic liquids (ILs, 1-methylimidazolium hydrogen sulfate (HmimHSO4, 1-ethyl-3-methylimidazolium hydrogen sulfate (HmimHSO4 and 1-butyl-3-methylimidazolium chloride (BmimCl as leaching agents was investigated in the leaching of copper and zinc from brass waste in the presence of an oxidant, hydrogen peroxide (H2O2. Factors that affect copper and zinc dissolution rates such as ionic liquid concentration, time and temperature were investigated. The results indicated that zinc was dissolved in leach solutions with EmimHSO4 and HmimHSO4, completely. Temperature had no considerable influence on copper dissolution rate whilst the rate increased with decreasing IL concentration. In the EmimHSO4 system, higher copper recoveries were achieved with 40% and 60% IL concentrations compared with IL concentrations of 20% and 80% at 40 °C leaching temperature. Copper dissolution rates decreased with EmimHSO4 concentration at 60 °C and 80 °C in the following order; 40% > 20% > 60% > 80%. On the other hand the leaching system with BmimCl generally resulted in poor extractions of copper and zinc.Este trabajo investiga el uso de líquidos iónicos (LIs, hidrogenosulfato de 1-metillimidazolio (HmimHSO4, hidrogenosulfato de 1-etil-3- metilimidazolio (EmimHSO4 y cloruro de 1-butil-1-metilimidazolio (BmimCl, como agentes de lixiviación de cobre y zinc a partir de residuos de latón en presencia de un oxidante, peróxido de hidrógeno (H2O2. Se estudiaron distintos factores que afectan a la velocidad de disolución del cobre y el zinc, como la concentración del líquido iónico, el tiempo y la temperatura. Los resultados indican que el zinc se disuelve completamente en las disoluciones que contienen EmimHSO4 y HmimHSO4. La temperatura no tiene un efecto significativo en la velocidad de disolución del cobre, mientras que dicha velocidad aumenta al disminuir la concentración del líquido iónico. En los sistemas que contienen EmimHSO4, los mejores

  13. Ion-water wires in imidazolium-based ionic liquid/water solutions induce unique trends in density.

    Science.gov (United States)

    Ghoshdastidar, Debostuti; Senapati, Sanjib

    2016-03-28

    Ionic liquid/water binary mixtures are rapidly gaining popularity as solvents for dissolution of cellulose, nucleobases, and other poorly water-soluble biomolecules. Hence, several studies have focused on measuring the thermophysical properties of these versatile mixtures. Among these, 1-ethyl-3-methylimidazolium ([emim]) cation-based ILs containing different anions exhibit unique density behaviours upon addition of water. While [emim][acetate]/water binary mixtures display an unusual rise in density with the addition of low-to-moderate amounts of water, those containing the [trifluoroacetate] ([Tfa]) anion display a sluggish decrease in density. The density of [emim][tetrafluoroborate] ([emim][BF4])/water mixtures, on the other hand, declines rapidly in close accordance with the experimental reports. Here, we unravel the structural basis underlying this unique density behavior of [emim]-based IL/water mixtures using all-atom molecular dynamics (MD) simulations. The results revealed that the distinct nature of anion-water hydrogen bonded networks in the three systems was a key in modulating the observed unique density behaviour. Vast expanses of uninterrupted anion-water-anion H-bonded stretches, denoted here as anion-water wires, induced significant structuring in [emim][Ac]/water mixtures that resulted in the density rise. Conversely, the presence of intermittent large water clusters disintegrated the anion-water wires in [emim][Tfa]/water and [emim][BF4]/water mixtures to cause a monotonic density decrease. The differential nanostructuring affected the dynamics of the solutions proportionately, with the H-bond making and breaking dynamics found to be greatly retarded in [emim][Ac]/water mixtures, while it exhibited a faster relaxation in the other two binary solutions.

  14. DFT Study on the Formation Mechanism of Normal and Abnormal N-Heterocyclic Carbene-Carbon Dioxide Adducts from the Reaction of an Imidazolium-Based Ionic Liquid with CO2.

    Science.gov (United States)

    Dong, Mengmeng; Gao, Jun; Liu, Chengbu; Zhang, Dongju

    2017-10-27

    To illustrate the formation mechanism of normal and abnormal N-heterocyclic carbene-carbon dioxide adducts (NHC-CO2 and aNHC-CO2), we implement density functional theory calculations on the reactions of two imidazolium-based ionic liquids ([C2C1Im][OAc] and [C2C1Im][CH3SO3]) with CO2. The reaction of [C2C1Im][OAc] with CO2 is mimicked using the gas phase model, implicit solvent model, and combined explicit-implicit solvent model. In the gas phase, the calculated barriers at 125 °C and 10 MPa are 12.1 kcal/mol for the formation of NHC-CO2 and 22.5 kcal/mol for the formation of aNHC-CO2, and the difference is significant (10.4 kcal/mol). However, the difference becomes less important (1.5 kcal/mol) as the solvation effect is considered more realistically using the combined explicit-implicit solvent model, rationalizing the experimental observation of aNHC-CO2 adduct in the [C2C1Im][OAc]-CO2 system. The anion of the ionic liquid is shown to play a substantial role, which can adjust the reactivity of imidazolium cation toward CO2: upon replacement of the basic [OAc](-) anion with a less basic [CH3SO3](-) anion, the reaction becomes very difficult, as indicated by high free energy barriers involved (41.4 kcal/mol for the formation of NHC-CO2 and 39.2 kcal/mol for the formation of aNHC-CO2). This is in agreement with the fact that neither NHC-CO2 or aNHC-CO2 is formed in the [C2C1Im][CH3SO3]-CO2 system, emphasizing the important dependence of the reactivity on the basicity of the anion of imidazolium-based ionic liquids for the formation of NHC- and aNHC-CO2 adducts.

  15. Chemically Cross-Linked MOF Membrane Generated from Imidazolium-Based Ionic Liquid-Decorated UiO-66 Type NMOF and Its Application toward CO2 Separation and Conversion.

    Science.gov (United States)

    Yao, Bing-Jian; Ding, Luo-Gang; Li, Fei; Li, Jiang-Tao; Fu, Qi-Juan; Ban, Yujie; Guo, Ang; Dong, Yu-Bin

    2017-10-25

    Carbon dioxide capture and transformation are of great importance to make cuts in greenhouse gas emissions. Nanometal-organic frameworks (NMOFs) could serve as ideal fillers for polymer membranes owing to their structural diversity and regulable microenvironment of the nanocage. Herein, a bifunctional, robust, and chemically cross-linked NMOF-based membrane was successfully constructed by the postsynthetic polymerization of imidazolium-based ionic liquid (IL)-decorated UiO-66 type nanoparticles (NPs) and the isocyanate-terminated polyurethane oligomer under mild conditions. The IL-modified MOF-polymer membranes exhibit a highly selective adsorption for CO2 over N2 and CH4. In addition, the obtained membrane can also be a highly active heterogeneous catalyst for CO2 transformation by cycloaddition with epoxide under an ambient pressure.

  16. Effects of methylation at position 2 of cation ring on rotational dynamics of imidazolium-based ionic liquids investigated by NMR spectroscopy: [C4mim]Br vs [C4C1mim]Br.

    Science.gov (United States)

    Endo, Takatsugu; Imanari, Mamoru; Seki, Hiroko; Nishikawa, Keiko

    2011-04-14

    We investigated the rotational dynamics of two imidazolium-based ionic liquids, 1-butyl-3-methylimidazolium bromide ([C(4)mim]Br) and 1-butyl-2,3-dimethylimidazolium bromide ([C(4)C(1)mim]Br), to reveal the effects of methylation at position 2 of the imidazolium ring (C(2) methylation). The rotational correlation time (τ(local)) for each carbon in the cations is derived from the spin-lattice relaxation time of (13)C nuclear magnetic resonance. The τ(local) results obtained here provide three principle insights into the rotational dynamics of ionic liquids. First, all τ(local) values for [C(4)C(1)mim]Br are greater than those for [C(4)mim]Br owing to a viscosity increase due to C(2) methylation. Second, the rate of change in τ(local) on C(2) methylation differs among the carbons in the cation, which indicates that each carbon has a different microviscosity. Third, the τ(local) increase in the (13)C at the root of the butyl group on C(2) methylation is very small compared to both intuitive prediction and the results from quantum chemical calculations. This indicates that the motion of the butyl group root in [C(4)C(1)mim]Br is not significantly inhibited by the methyl group at the position 2 of the imidazolium ring. The finding provides conclusive information on the origin of the increases in the melting point on C(2) methylation. Hunt previously found through calculation that decreases in entropy are caused by two factors, namely, reductions in the rotational mobility of the butyl group and in the number of stable anion interaction sites with C(2) methylation, resulting in an increase in melting point and viscosity. Our finding experimentally illustrates that the origin of the increases in melting point is not the inhibition of butyl group motion and that the reduction in stable anion interaction sites plays a major role in the increases. Additionally, it is suggested that the viscosity increase on C(2) methylation can be interpreted in the same manner.

  17. Two Zn and Hg bromide salts based on 1-ethyl-3-methyl imidazolium ionic liquid: Ionothermal synthesis, structures and supramolecular organization

    Directory of Open Access Journals (Sweden)

    Xiu-Cheng Zhang

    2012-12-01

    Full Text Available Two Zn(II and Hg(II bromide salts, [EMI]2[ZnBr4] (1 and [EMI][HgBr3] (2, have been synthesized under ionothermal conditions using 1-ethyl-3-methyl imidazolium bromide ([EMI]Br as solvents. 1 consists of tetrahedral anion [ZnBr4]2− and 2 consists of 1D double chain locating in the cavities surrounded by [EMI]+ cations. Both compounds exhibit 3D supramolecular architectures organized by the C-H•••Br hydrogen bondings and alkyl-alkyl interactions.DOI: http://dx.doi.org/10.4314/bcse.v26i3.9

  18. Theoretical Elucidation of the Mechanism and Kinetic Experimental Phenomena on the Esterification of Alpha-Tocopherol with Succinic Anhydride: Catalyses of a Histidine Derivative vs. an Imidazolium-based Ionic Liquid.

    Science.gov (United States)

    Jing, Yaru; Zhu, Rongxiu; Liu, Chengbu; Zhang, Dongju

    2017-10-30

    DFT calculations have been conducted to gain insight into the mechanism and kinetics of the esterification of α-tocopherol with succinic anhydride catalyzed by a histidine derivative or an imidazolium-based ionic liquid (IL). The two catalytic reactions involve an intrinsically consistent molecular mechanism: a rate-determining, concerted nucleophilic substitution followed by a facile proton transfer process. The histidine derivative or the IL anion is shown to play a decisive role, which acts a Brönsted base abstracting the hydroxyl proton of α-tocopherol to favor the nucleophilic substitution of the hydroxyl oxygen of α-tocopherol on succinic anhydride. The calculated free energy barriers of two reactions (15.8 kcal/mol for the histamine-catalyzed reaction and 22.9 kcal/mol for the IL-catalyzed reaction) together with their respective characteristic features, the catalytic reaction with a catalytic amount of histamine vs. the catalytic reaction with an excessed amount of the IL, rationalize well the experimentally observed kinetics that the former has faster initial rate but longer reaction time while the latter is initiated slowly but completed in a much shorter time.

  19. Role of the Electrostatic Interactions in the Stabilization of Ionic Liquid Crystals: Insights from Coarse-Grained MD Simulations of an Imidazolium Model.

    Science.gov (United States)

    Saielli, Giacomo; Wang, Yanting

    2016-09-01

    In order to investigate the role of the electrostatic interactions in stabilizing various phases of ionic liquids, especially smectic ionic liquid crystals, we have employed a coarse-grained model of 1-hexadecyl-3-methylimidazolium nitrate, [C16mim][NO3], to perform molecular dynamics simulations with the partial charges artificially rescaled by a factor from 0.7 to 1.2. The simulated systems have been characterized by means of orientational and translational order parameters and by distribution functions. We have found that increasing the total charge of the ions strongly stabilizes the ionic smectic phase by shifting the clearing point (melting into the isotropic liquid phase) to higher temperatures, while a smaller effect is observed on the stability of the crystal phase. Our results highlight the importance of the electrostatic interactions in promoting the formation of ionic liquid crystals through microphase segregation. Moreover, as the total charge of the model is increased, we observe a transformation from a homogeneous to a nanosegregated isotropic structure typical of ionic liquids. Therefore, a connection can be established between the degree of nanosegregation of ILs and the stability of ILC phases. All the above can be understood by the competition among electrostatic interactions between charged groups (cationic head groups and anions), van der Waals interactions between nonpolar cationic tail groups, and thermal fluctuations.

  20. Modulation of the aggregation properties of sodium deoxycholate in presence of hydrophilic imidazolium based ionic liquid: water dynamics study to probe the structural alteration of the aggregates.

    Science.gov (United States)

    Kundu, Niloy; Banik, Debasis; Roy, Arpita; Kuchlyan, Jagannath; Sarkar, Nilmoni

    2015-10-14

    In this article, we have investigated the effect of a hydrophilic ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]-BF4), on the aggregation properties of a biological surfactant, sodium deoxycholate (NaDC), in water. In solution, unlike conventional surfactants it shows stepwise aggregation and the effect of the conventional ionic liquid on the aggregation properties is rather interesting. We have observed concentration dependent dual role of the ionic liquid; at their low concentration, the aggregated structure of NaDC reorganizes itself into an elongated rod like structure. However, the aggregated network is disintegrated into small aggregates upon further addition of ionic liquid. TEM (Transmission Electron Microscopy), SEM (Scanning Electron Microscopy) and FLIM (Fluorescence Lifetime Imaging Microscopy) images also confirmed the structural alteration of NaDC upon varying the concentration of the ionic liquid. The proton NMR data indicate that hydrophobic as well as electrostatic interaction is solely responsible for such structural adaptation of NaDC in the presence of an ionic liquid. The host-guest interaction inside the aggregates is monitored using Coumarin-153 (C-153) and the location of C-153 is probed by varying the excitation wavelength from 375 nm to 440 nm and the two binding sites of the aggregates are affected in a different fashion in the presence of ionic liquid. Excitation in the blue region selects the fluorophores which preferably bind to the buried region of the aggregates, whereas 440 nm excitation corresponds to the guest molecules which are exposed to the solvent molecules. The average solvation time of C-153 is increased in the presence of 1.68 wt% [bmim]-BF4 at λexc = 440 nm i.e. the probe molecules relocate themselves to a more restricted region. However, the average solvation time became 2.6 times faster in the presence of 11.2 wt% [bmim]-BF4, which corresponds to a more polar and exposed region. The time resolved

  1. Infrared studies of PVC-based electrolytes incorporated with lithium triflate and 1-butyl-3-methyl imidazolium trifluoromethanesulfonate as ionic liquid

    Science.gov (United States)

    Zulkepeli, Nik A. S. Nik; Winie, Tan; Subban, R. H. Y.

    2017-09-01

    In this work, 1-butyl-3-methylimidazolium trifluoromethanesulfonate (BMIMCF3SO3) is employed as ionic liquid in PVC-based polymer electrolyte system with lithium triflate (LiCF3SO3) as doping salt. The samples in film form were prepared by quantitatively varying the concentration of BMIMCF3SO3 to a fixed ratio of PVC-LiCF3SO3 using solution cast technique. The highest room temperature ionic conductivity of 1.120 × 10-7 Scm-1 was exhibited by PVC-LiCF3SO3-BMIMCF3SO3 containing 3 wt. % BMIMCF3SO3. FTIR spectra of the polymer electrolytes were examined to study the complexation of the PVC-based polymer electrolytes. Intensity of free ions, ion pairs, and ion aggregates were obtained from FTIR deconvolution in an attempt to correlate with ionic conductivity results. The intensity of free ions was found to be high for sample with 3 wt. % BMIMCF3SO3.

  2. Aging Effects on the Properties of Imidazolium-, Quaternary Ammonium-, Pyridinium-, and Pyrrolidinium-Based Ionic Liquids Used in Fuel and Energy Production

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Elise B.; Smith, L. Taylor; Williamson, Tyler K.; Kendrick, Sarah E.

    2013-11-21

    Ionic liquids (ILs) are often cited for their excellent thermal stability, a key property for their use as solvents and in the chemical processing of biofuels. However, there has been little supporting data on the long-term aging effect of the temperature on these materials. Imizadolium-, quaternary ammonium-, pyridinium-, and pyrrolidnium-based ILs with the bis(trifluoromethylsulfonyl)imide and bis(perfluoroethylsulfonyl)imide anions were aged for 2520 h (15 weeks) at 200 °C in air to determine the effects of an oxidizing environment on their chemical structure and thermal stability over time. Finally, it was found that the minor changes in the cation chemistry could greatly affect the properties of the ILs over time.

  3. Comprehensive Computational and Experimental Analysis of Biomaterial toward the Behavior of Imidazolium-Based Ionic Liquids: An Interplay between Hydrophilic and Hydrophobic Interactions.

    Science.gov (United States)

    Umapathi, Reddicherla; Vepuri, Suresh B; Venkatesu, Pannuru; Soliman, Mahmoud E

    2017-05-11

    To provide insights into the aggregation behavior, hydration tendency and variation in phase transition temperature produced by the addition of ionic liquids (ILs) to poly(N-isopropylacrylamide) (PNIPAM) aqueous solution, systematic physicochemical studies, and molecular dynamic simulations were carried out. The influence of ILs possessing the same [Cl](-) anion and a set of cations [Cnmim](+) with increasing alkyl chain length such as 1-ethyl-3-methylimidazolium ([Emim](+)), 1-allyl-3-methylimidazolium ([Amim](+)), 1-butyl-3-methylimidazolium ([Bmim](+)), 1-hexyl-3-methylimidazolium ([Hmim](+)), 1-benzyl-3-methylimidazolium ([Bzmim](+)), and 1-decyl-3-methylimidazolium ([Dmim](+)) on the phase transition of PNIPAM was monitored by the aid of UV-visible absorption spectra, fluorescence intensity spectra, viscosity (η), dynamic light scattering (DLS), and Fourier transform infrared (FTIR) spectroscopy. Furthermore, to interpret the direct images and surface morphologies of the PNIPAM-IL aggregates, we performed field emission scanning electron microscopy (FESEM). The overall specific ranking of ILs in preserving the hydration layer around the PNIPAM aqueous solution was [Emim][Cl] > [Amim][Cl] > [Bmim][Cl] > [Hmim][Cl] > [Bzmim][Cl] > [Dmim][Cl]. Moreover, to investigate the molecular mechanism behind the change in the lower critical solution temperature (LCST) of the polymer in the presence of the ILs, a molecular dynamics (MD) study was performed. The MD simulation has clearly shown the reduction in hydration shell of the polymer after interacting with the ILs at their respective LCST. MD study revealed significant changes in polymer conformation because of IL interactions and strongly supports the experimental observation of polymer phase transition at a temperature lower than typical LCST for all the studied ILs. The driving force for concomitant sharp configurational transition has been attributed to the displacement of water molecules on the polymer surface

  4. Structural Dynamics and Evolution of Bismuth Electrodes during Electrochemical Reduction of CO 2 in Imidazolium-Based Ionic Liquid Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Medina-Ramos, Jonnathan [Chemical; Lee, Sang Soo [Chemical; Fister, Timothy T. [Chemical; Hubaud, Aude A. [Chemical; Sacci, Robert L.; Mullins, David R.; DiMeglio, John L. [Department; Pupillo, Rachel C. [Department; Velardo, Stephanie M. [Department; Lutterman, Daniel A.; Rosenthal, Joel [Department; Fenter, Paul [Chemical

    2017-09-14

    Real-time changes in the composition and structure of bismuth electrodes used for catalytic conversion of CO2 into CO were examined via X-ray absorption spectroscopy (including XANES and EXAFS), electrochemical quartz crystal microbalance (EQCM), and in situ X-ray reflectivity (XR). Measurements were performed with bismuth electrodes immersed in acetonitrile (MeCN) solutions containing a 1-butyl-3-methylimidazolium ([BMIM]+) ionic liquid promoter or electrochemically inactive tetrabutylammonium supporting electrolytes (TBAPF6 and TBAOTf). Altogether, these measurements show that bismuth electrodes are originally a mixture of bismuth oxides (including Bi2O3) and metallic bismuth (Bi0) and that the reduction of oxidized bismuth species to Bi0 is fully achieved under potentials at which CO2 activation takes place. Furthermore, EQCM measurements conducted during cyclic voltammetry revealed that a bismuth-coated quartz crystal exhibits significant shifts in resistance (ΔR) prior to the onset of CO2 reduction near -1.75 V vs Ag/AgCl and pronounced hysteresis in frequency (Δf) and ΔR, which suggests significant changes in roughness or viscosity at the Bi/[BMIM]+ solution interface. In situ XR performed on rhombohedral Bi (001) oriented films indicates that extensive restructuring of the bismuth film cathodes takes place upon polarization to potentials more negative than -1.6 V vs Ag/AgCl, which is characterized by a decrease of the Bi (001) Bragg peak intensity of ≥50% in [BMIM]OTf solutions in the presence and absence of CO2. Over 90% of the reflectivity is recovered during the anodic half-scan, suggesting that the structural changes are mostly reversible. In contrast, such a phenomenon is not observed for thin Bi (001) oriented films in solutions of tetrabutylammonium salts that do not promote CO2 reduction. Overall, these results highlight that Bi electrodes undergo significant potential-dependent chemical and structural transformations in the presence of [BMIM

  5. Investigation of toxic effects of imidazolium ionic liquids, [bmim][BF4] and [omim][BF4], on marine mussel Mytilus galloprovincialis with or without the presence of conventional solvents, such as acetone.

    Science.gov (United States)

    Tsarpali, Vasiliki; Belavgeni, Alexia; Dailianis, Stefanos

    2015-07-01

    This study investigated the cytotoxic, oxidative and genotoxic effects of two commonly used imidazolium ionic liquids (ILs), [bmim][BF4] (1-butyl-3-methylimidazolium) and [omim][BF4] (1-methyl-3-octylimidazolium tetrafluoroborate), on the marine mussel Mytilus galloprovincialis, as well as whether acetone could mediate their toxic profile. In this context, mussels were firstly exposed to different concentrations of [bmim][BF4] or [omim][BF4], with or without the presence of acetone (at a final concentration of 0.06% v/v), for a period of 96h, in order to determine the concentration that causes 50% mussel mortality (LC50 values) in each case. Thereafter, mussels were exposed to sub- and non-lethal concentrations of ILs for investigating their ability to cause lysosomal membrane impairment (with the use of neutral red retention assay/NRRT), superoxide anion and lipid peroxidation byproduct (malondialdehyde/MDA) formation, as well as DNA damage and formation of nuclear abnormalities in hemocytes. The results showed that [omim][BF4] was more toxic than [bmim][BF4] in all cases, while the presence of acetone resulted in a slight attenuation of its toxicity. The different toxic behavior of ILs was further revealed by the significantly lower levels of NRRT values observed in [omim][BF4]-treated mussels, compared to those occurring in [bmim][BF4] in all cases. Similarly, [bmim][BF4]-mediated oxidative and genotoxic effects were observed only in the highest concentration tested (10mgL(-1)), while [omim][BF4]-mediated effects were enhanced at lower concentrations (0.01-0.05mgL(-1)). Overall, the present study showed that [bmim][BF4] and [omim][BF4] could induce not only lethal but also nonlethal effects on mussel M. galloprovincialis. The extent of [bmim][BF4] and/or [omim][BF4]-mediated effects could be ascribed to the length of each IL alkyl chain, as well as to their lipophilicity. Moreover, the role of acetone on the obtained toxic effects of the specific ILs was

  6. Evidence that imidazolium-based ionic ligands can be metal(0)/nanocluster catalyst poisons in at least the test case of iridium(0)-catalyzed acetone hydrogenation.

    Science.gov (United States)

    Ott, Lisa Starkey; Campbell, Sarah; Seddon, Kenneth R; Finke, Richard G

    2007-11-26

    This study begins with the question of whether ionic liquids (ILs), such as 1-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF6], can be catalyst poisons for transition-metal catalysts rather than a preferred stabilizing media as typically assumed in the literature. The test case of acetone (propanone) hydrogenation is picked for two reasons: (i) acetone hydrogenation is important for its applications in heat pumps, H2 storage schemes, and fuel cells and for the commercial value of the resultant product, propan-2-ol, and (ii) two recent, independent studies have reported putative Ir(0)n nanocluster-catalyzed hydrogenations of acetone beginning in each case with the identical precursor, [{(COD)IrCl}2] (where COD=1,5-cyclooctadiene) (1). A close comparison of the results of those two literature studies and their related, but different, experimental conditions (vide infra) suggests the hypothesis that the IL is actually a catalyst poison. Indeed, the investigations herein (i) find that 1.0 equiv of added IL, [bmim][PF6], completely inhibits the formation of Ir(0)n nanoclusters under conditions 1 in Table 1 in the main text (namely, 3.6 mM precatalyst 1, 22 degrees C, and 2.76 bar H2) and (ii) demonstrate that 0.1 and 1.0 equivs of this same IL, [bmim][PF6], poisons 74 and 90%, respectively, of the acetone hydrogenation activity of premade, previously catalytically active nanoclusters. The above results in turn compelled a reinvestigation of the claim that Ir(0)n nanoclusters are the catalyst in what was reported as a colloidal suspension prepared under conditions 2 in Table 1 of the main text (namely, 52 mM precursor 1, 92 equiv of IL, 75 degrees C, and 4.05 bar of H2). We further (iii) find that the colloidal suspension prepared under conditions 2 is a mixture of unreacted precursor, 1, some nanoclusters, and isolable bulk metal, and we also (iv) find, somewhat surprisingly, in light of the IL-poisoning results found under conditions 1, that the Ir(0

  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. Investigation of toxic effects of imidazolium ionic liquids, [bmim][BF{sub 4}] and [omim][BF{sub 4}], on marine mussel Mytilus galloprovincialis with or without the presence of conventional solvents, such as acetone

    Energy Technology Data Exchange (ETDEWEB)

    Tsarpali, Vasiliki; Belavgeni, Alexia; Dailianis, Stefanos, E-mail: sdailianis@upatras.gr

    2015-07-15

    Highlights: • The toxic effects of [bmim][BF{sub 4}] and [omim][BF{sub 4}] on mussels were investigated. • Both ILs could induce lethal and nonlethal effects on Mytilus galloprovincialis. • Different extent of IL-mediated adverse effects was observed in mussel hemocytes. • The alkyl chain length and lipophilicity of ILs are crucial for their toxicity. • Acetone influences the oxidative and genotoxic effects of [omim][BF{sub 4}]. - Abstract: This study investigated the cytotoxic, oxidative and genotoxic effects of two commonly used imidazolium ionic liquids (ILs), [bmim][BF{sub 4}] (1-butyl-3-methylimidazolium) and [omim][BF{sub 4}] (1-methyl-3-octylimidazolium tetrafluoroborate), on the marine mussel Mytilus galloprovincialis, as well as whether acetone could mediate their toxic profile. In this context, mussels were firstly exposed to different concentrations of [bmim][BF{sub 4}] or [omim][BF{sub 4}], with or without the presence of acetone (at a final concentration of 0.06% v/v), for a period of 96 h, in order to determine the concentration that causes 50% mussel mortality (LC{sub 50} values) in each case. Thereafter, mussels were exposed to sub- and non-lethal concentrations of ILs for investigating their ability to cause lysosomal membrane impairment (with the use of neutral red retention assay/NRRT), superoxide anion and lipid peroxidation byproduct (malondialdehyde/MDA) formation, as well as DNA damage and formation of nuclear abnormalities in hemocytes. The results showed that [omim][BF{sub 4}] was more toxic than [bmim][BF{sub 4}] in all cases, while the presence of acetone resulted in a slight attenuation of its toxicity. The different toxic behavior of ILs was further revealed by the significantly lower levels of NRRT values observed in [omim][BF{sub 4}]-treated mussels, compared to those occurring in [bmim][BF{sub 4}] in all cases. Similarly, [bmim][BF{sub 4}]-mediated oxidative and genotoxic effects were observed only in the highest

  9. Simultaneous determination of acrylamide, asparagine and glucose in food using short chain methyl imidazolium ionic liquid based ultrasonic assisted extraction coupled with analyte focusing by ionic liquid micelle collapse capillary electrophoresis.

    Science.gov (United States)

    Abd El-Hady, Deia; Albishri, Hassan M

    2015-12-01

    Acrylamide (AA) is a known lethal neurotoxin and carcinogen. AA is formed in foods during the browning process by the Maillard reaction of glucose (GL) with asparagine (AS). For the first time, the simultaneous online preconcentration and separation of AA, AS and GL using analyte focusing by ionic liquid micelle collapse capillary electrophoresis (AFILMC) was presented. Samples were prepared in a 1-butyl-3-methylimidazolium bromide (BMIMBr) micellar matrix with a conductivity 4 times greater than that of the running buffer (12.5 mmol L(-1) phosphate buffer at pH 8.5). Samples were hydrodynamically injected into a fused silica capillary at 25.0 mbar for 25.0 s. Separations were performed by applying a voltage of 25.0 kV and a detection at 200.0 nm. To sufficiently reduce BMIMBr adsorption on the interior surface of capillary, an appropriate rinsing procedure by hydrochloric acid and water was optimized. AFILMC measurements of analytes within the concentration range of 0.05-10.0 μmol L(-1) achieved adequate reproducibility and accuracy with RSD 1.14-3.42% (n=15) and recovery 98.0-110.0%, respectively. Limits of detections were 0.71 ng g(-1) AA, 1.06 ng g(-1) AS and 27.02 ng g(-1) GL with linearity ranged between 2.2 and 1800 ng g(-1). The coupling of AFILMC with IL based ultrasonic assisted extraction (ILUAE) was successfully applied to the efficient extraction and determination of AA, AS and GL in bread samples. The structure of ILs has significant effects on the extraction efficiency of analytes. The optimal extraction efficiency (97.8%) was achieved by an aqueous extraction with 4:14 ratio of sample: 3.0 mol L(-1) BMIMBr followed by sonication at 35 °C. The proposed combination of ILUAE and AFILMC was simple, ecofriendly, reliable and inexpensive to analyze a toxic compound and its precursors in bread which is applicable to food safety. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Synthesis and Characterization of Novel Dimeric Ionic Liquids by Conventional Approaches

    Directory of Open Access Journals (Sweden)

    Yatimah Alias

    2008-07-01

    Full Text Available The 1H-NMR shifts of the imidazolium protons of some novel dimeric ionic liquids were examined in various deuterated solvents. Interactions between the solvent and the imidazolium salt of butyl substituted ionic liquids were observed to give higher chemical shifts than methyl substitution.

  11. 18-Crown[6]ether functionalized reduced graphene oxide for membrane-free ion selective sensing

    DEFF Research Database (Denmark)

    Olsen, Gunnar; Ulstrup, Jens; Chi, Qijin

    The focus of this work is on the synthesis of a 1-Aza-18-crown[6]ether functionalized reduced graphene oxide (RGO-crown[6]) with specific K+ binding sites on the RGO surface. Glassy carbon electrodes (GCE) functionalized with RGO-crown[6] weretested for selective potentiometric sensing of K...

  12. Improvement of the chromatographic separation performance of an imidazolium ionic liquid functionalized silica column by in situ anion-exchange with dodecyl sulfonate and dodecylbenzene sulfonate anions.

    Science.gov (United States)

    Sun, Min; Feng, Juanjuan; Chen, Wenjie; Li, Leilei; Duan, Huimin; Luo, Chuannan

    2014-06-01

    The anionic part of ionic liquids can provide additional interactions during chromatographic separations. In this work, the chromatographic separation performance of a silica column functionalized with 1-propyl-3-methylimidazolium chloride ionic liquid was improved by in situ anion-exchange from chloride anions to dodecyl sulfonate anions and dodecylbenzene sulfonate anions. The separation performances of these ionic liquid functionalized phases were investigated and compared with each other using polycyclic aromatic hydrocarbons, phthalates, parabens, and phenols as model compounds. Results indicated that the new columns presented a better chromatographic separation than the original one. This was ascribed retention mechanism from organic anions. The introduction of dodecyl sulfonate anions increased the hydrophobicity of stationary phase. Furthermore, the phenyl groups of dodecylbenzene sulfonate anions could provide an enhanced selectivity to aromatic compounds such as polycyclic aromatic hydrocarbons by π-π interactions. Analysis repeatability of the new columns was satisfactory (RSD of retention time, 0.10-0.40%; RSD of peak area, 0.66-0.84%). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Cu(II complexes of an ionic liquid-based Schiff base [1-{2-(2-hydroxy benzylidene amino ethyl}-3-methyl­imidazolium]Pf6: Synthesis, characterization and biological activities

    Directory of Open Access Journals (Sweden)

    Saha Sanjoy

    2015-01-01

    Full Text Available Two Cu(II complexes of an ionic liquid based Schiff base 1-{2-(2-hydroxybenzylideneamino ethyl}-3-methylimidazolium hexaflurophosphate, were prepared and characterized by different analytical and spectroscopic methods such as elemental analysis, magnetic susceptibility, UV-Vis, IR, NMR and mass spectroscopy. The Schiff base ligand was found to act as a potential bidentate chelating ligand with N, O donor sites and formed 1:2 metal chelates with Cu(II salts. The synthesized Cu(II complexes were tested for biological activity.

  14. 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.

  15. Design and Synthesis of Crown Ether Functionalized Imidazoles as a New type of Building Blocks

    Directory of Open Access Journals (Sweden)

    Sheng-Hui Li

    2012-01-01

    Full Text Available A simple, convenient and efficient synthesis for a series of crown ether functionalized imidazoles from benzo-15-crown-5 (B15C5, benzo-18-crown-6 (B18C6, imidazole (Im, 2-methylimidazole (mIm, benzimidazole (bIm and 2-methyl benzimidazole (mbIm is reported. All these compounds obtained were characterized by IR, 1H NMR, ESI-MS and elemental analysis.

  16. Imidazolium compounds are active against all stages of Trypanosoma cruzi.

    Science.gov (United States)

    Faral-Tello, Paula; Liang, Mary; Mahler, Graciela; Wipf, Peter; Robello, Carlos

    2014-03-01

    Imidazolium salts are best known for their applications in organic synthesis as room-temperature ionic liquids, or as precursors of stable carbenes, but they also show important biological properties such as anti-oxidative effects, induction of mitochondrial membrane permeabilisation and inhibition of the infection cycle of Plasmodium falciparum. For these reasons, and since chemotherapy for Chagas disease is inefficient, the aim of this study was to test the use of imidazolium compounds against the kinetoplastid haemoflagellate aetiological agent for this disease, namely Trypanosoma cruzi. The results show that five of the tested compounds are more effective than the reference drug benznidazole against the epimastigote and trypomastigote forms of T. cruzi. Moreover, intracellular amastigotes were also affected by the compounds, which showed lower toxicity in host cells. Transmission electron microscopy analysis demonstrated that the tested agents induced alterations of the kinetoplast and particularly of the mitochondria, leading to extraordinary swelling of the organelle. These results further demonstrate that the test agents with the best profile are those bearing symmetrical bulky substituents at N(1) and N(3), displaying promising activity against all forms of T. cruzi, interesting selectivity indexes and exceptional activity at low doses. Accordingly, these agents represent promising candidates for the treatment of Chagas disease. Copyright © 2013 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  17. 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.

  18. (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.

  19. Water Phase Diagram Is Significantly Altered by Imidazolium Ionic Liquid

    DEFF Research Database (Denmark)

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

    2014-01-01

    We report unusually large changes in the boiling temperature, saturated vapor pressure, and structure of the liquid-vapor interface for a range of 1-butyl-3-methyl tetrafluoroborate, [C4C1IM][BF4]-water mixtures. Even modest molar fractions of [C4C1IM][BF4] significantly affect the phase behavior...... of water, as represented, for instance, by strong negative deviations from Raoult's law, extending far beyond the standard descriptions. The investigation was carried out using classical molecular dynamics employing a specifically refined force field. The changes in the liquid-vapor interface and saturated...

  20. A Highly Viscous Imidazolium Ionic Liquid inside Carbon Nanotubes

    DEFF Research Database (Denmark)

    Ohba, T.; Chaban, Vitaly V.

    2014-01-01

    We report a combined experimental (X-ray diffraction) and theoretical (molecular dynamics, hybrid density functional theory) study of 1-ethyl-3-methylimidazolium chloride, [C2C1MIM][Cl], inside carbon nanotubes (CNTs). We show that despite its huge viscosity [C2C1MIM][Cl] readily penetrates into 1...... adsorption of [C2C1MIM][Cl] on the inner sidewalls of 1-3 nm carbon nanotubes....

  1. 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.

  2. 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

  3. The facile construction of an anion exchange membrane with 3D interconnected ionic nano-channels.

    Science.gov (United States)

    Gao, Xinpei; Lu, Fei; Liu, Yizhi; Sun, Na; Zheng, Liqiang

    2017-01-05

    The co-organization of polymerizable imidazolium-based ionic liquids and p-xylene led to the formation of a bicontinuous cubic phase with a primitive-type periodic minimal surface, and for the first time an anion exchange membrane preserving 3D interconnected ionic nano-channels was fabricated through in-phase photopolymerization of bicontinuous cubic liquid crystals.

  4. Interactions in 1-ethyl-3-methyl imidazolium tetracyanoborate ion pair: Spectroscopic and density functional study

    Energy Technology Data Exchange (ETDEWEB)

    Mao, James X.; Lee, Anita S.; Kitchin, John R.; Nulwala, Hunaid B.; Luebke, David R.; Damodaran, Krishnan

    2013-01-25

    Density Functional Theory is used to investigate a weakly coordinating room-temperature ionic liquid, 1-ethyl-3-methyl imidazolium tetracyanoborate ([Emim]{sup +}[TCB]{sup -}). Four locally stable conformers of the ion pair were located. Atoms-in-molecules (AIM) and electron density analysis indicated the existence of several hydrogen bonds. Further investigation through the Natural Bond Orbital (NBO) and Natural Energy Decomposition Analysis (NEDA) calculations provided insight into the origin of interactions in the [Emim]{sup +}[TCB]{sup -} ion pair. Strength of molecular interactions in the ionic liquid was correlated with frequency shifts of the characteristic vibrations of the ion pair. Harmonic vibrations of the ion pair were also compared with the experimental Raman and Infrared spectra. Vibrational frequencies were assigned by visualizing displacements of atoms around their equilibrium positions and through Potential Energy Distribution (PED) analysis.

  5. 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.

  6. An insight into the influence of hydrogen bond acceptors on cellulose/1-allyl-3-methyl imidazolium chloride solution.

    Science.gov (United States)

    Jiang, Jiahao; Xiao, Yafei; Huang, Wenjuan; Gong, Peixin; Peng, Shuhua; He, Jianping; Fan, Minmin; Wang, Ke

    2017-12-15

    Although ionic liquids have been well established as effective solvents for the dissolution and processing of natural cellulose fibers, the detailed dissolution mechanism at the molecular level still remains unclear. Herein, the turbidimetric measurement showed that the solubility of cellulose in 1-allyl-3-methyl imidazolium chloride (AmimCl) decreased with increasing temperature. The temperature dependence of the OH stretching vibration band of cellulose in AmimCl was investigated by infrared spectroscopy. The interaction between AmimCl and different hydrogen bond acceptors were investigated by turbidimetry and NMR spectroscopy, which indicated that the excellent compatibility of the hydrogen bond acceptors with AmimCl provides more interaction sites for the hydroxyl groups of the cellulose. In addition, ionic liquids with a similar anionic structure of hydrogen bond acceptors have been synthesized. This study provides a green and safe guide for the preparation of ionic liquids with excellent solubility of cellulose. Copyright © 2017. Published by Elsevier Ltd.

  7. 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.

  8. Crystal structure and electrical conductivity of imidazolium succinate

    Energy Technology Data Exchange (ETDEWEB)

    Pogorzelec-Glaser, K.; Pawlaczyk, C.; Markiewicz, E. [Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznan (Poland); Pietraszko, A. [Institute of Low Temperature and Structure Research, Okolna 2, 50-422 Wroclaw (Poland)

    2007-11-15

    Small single crystals of the imidazolium succinate were grown and their structure was re-examined using the X-ray diffraction method and a probable protonic conduction mechanism has been proposed. The electric conductivity of the powdered tablets was measured using the impedance spectroscopy method. The range of obtained values of conductivity as well as the activation energy (0.65 eV) of the imidazolium succinate is close to these of imidazolium malonate and imidazolium glutarate investigated previously [K. Pogorzelec-Glaser, J. Garbarczyk, Cz. Pawlaczyk, E. Markiewicz, Materials Science Poland 24 (2006) 245-253]. Metastable and virtual positions for proton transfer were indicated by means of calculations of the atomic displacement factors and the probability density function. (author)

  9. Gold nanoparticles supported by imidazolium-based porous organic polymers for nitroarene reduction.

    Science.gov (United States)

    Su, Yanqing; Li, Xiaoju; Wang, Yangxin; Zhong, Hong; Wang, Ruihu

    2016-11-14

    Two imidazolium-based porous organic polymers (Im-POP-1 and Im-POP-2) were synthesized through the Yamamoto reaction of different molar ratios of 1,3-bis(4-bromophenyl)imidazolium bromide and tetrakis(4-bromophenyl)methane, subsequent anion exchange with HAuCl4 and reduction with NaBH4 produced well-dispersed gold nanoparticles (NPs), Au@Im-POP-1 and Au@Im-POP-2. These NPs possess a small size and narrow size distribution, their application in the reduction of nitroarenes was evaluated, and the reduction process was tracked by (13)C NMR experiments for reaction mechanism studies. In comparison with gold NPs supported by a non-ionic analogue from the Yamamoto reaction of tetrakis(4-bromophenyl)methane (Au@POP-TPM), Au@Im-POP-2 exhibits high catalytic activity, good selectivity of aniline and superior recyclability in nitrobenzene reduction. The gold NPs in Au@Im-POP-2 increase slightly after four consecutive reaction runs, while an apparent agglomeration of NPs in Au@POP-TPM was observed after the second run. This research provides a new type of support for the stabilization of gold NPs and for the improvement of catalytic performances.

  10. 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.

  11. 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.

  12. 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.

  13. The Depolymerization of Poly(Ethylene Terephthalate) (PET) Using N-Heterocyclic Carbenes from Ionic Liquids

    Science.gov (United States)

    Kamber, Nahrain E.; Tsujii, Yasuhito; Keets, Kate; Waymouth, Robert M.; Pratt, Russell C.; Nyce, Gregory W.; Hedrick, James L.

    2010-01-01

    The depolymerization of the plastic polyethylene terephthalate (PET or PETE) is described in this laboratory procedure. The transesterification reaction used to depolymerize PET employs a highly efficient N-heterocyclic carbene catalyst derived from a commercially available imidazolium ionic liquid. N-heterocyclic carbenes are potent nucleophilic…

  14. Thermo- and electro-dual responsive poly(ionic liquid) electrolyte based smart windows.

    Science.gov (United States)

    Chen, Fei; Ren, Yongyuan; Guo, Jiangna; Yan, Feng

    2017-01-31

    Thermo- and electro-dual responsive poly(ionic liquid) (PIL) based electrolytes were synthesized by co-polymerization of N-isopropylacrylamide (NIPAM) with (or without) 3-butyl-1-vinyl-imidazolium bromide ([BVIm][Br]) using diallyl-viologen (DAV) as both the cross-linking agent and electrochromic material.

  15. Electrografting of stimuli-responsive, redox active organometallic polymers to gold from ionic liquids.

    Science.gov (United States)

    Feng, Xueling; Sui, Xiaofeng; Hempenius, Mark A; Vancso, G Julius

    2014-06-04

    Robust, dense, redox active organometallic poly(ferrocenylsilane) (PFS) grafted films were formed within 5 min by cathodic reduction of Au substrates, immersed in a solution of imidazolium-functionalized PFS chains in the ionic liquid 1-ethyl-3-methylimidazolium ethyl sulfate. The electrografted polymer films were employed as an electrochemical sensor, exhibiting high sensitivity, stability, and reproducibility.

  16. Ion Exchange Chromatography-Indirect Ultraviolet Detection for Separation and Determination of Morpholinium Ionic Liquid Cations.

    Science.gov (United States)

    Zhang, Yu; Ma, Yajie; Yu, Hong; Liu, Yongqiang

    2017-01-01

    A rapid analytical method of ion exchange chromatography with indirect ultraviolet detection was developed to determine morpholinium ionic liquid (IL) cations, i.e. N-methyl-N-ethyl morpholinium cation ([MEMo]+) and N-methyl-N-propyl morpholinium cation ([MPMo]+). Chromatographic separation of morpholinium cations was performed on a sulfonic acid base cation exchange column using imidazolium ionic liquid-organic solvent as mobile phase. The effects of chromatographic columns, ultraviolet absorption reagents, imidazolium ILs, detection wavelength, organic solvents, pH values of the mobile phase and column temperature on the retention of morpholinium cations were investigated. The retention times of the cations were clearly decreased by the increase of the alkyl substituent length on imidazolium cation or with the increase of the concentration of 1-ethyl-3-methyl imidazolium tetrafluoroborate. The molecular structure of the anion of imidazolium IL which has UV absorption has influence on determination of the analytes. Under the optimal conditions, the detection limits (signal-to-noise ratio, S/N = 3) were 0.29 and 0.44 mg L-1 The method has been successfully applied to the determination of two ILs synthesized by chemistry laboratory. The method uses the liquid chromatography system, which is widely available in general laboratories, and the simple composition of mobile phase, thus make the quantitative analysis of no UV absorption morpholinium cations possible. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. 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.

  18. Ionic Liquid-Nanoparticle Hybrid Electrolytes and their Application in Secondary Lithium-Metal Batteries

    KAUST Repository

    Lu, Yingying

    2012-07-12

    Ionic liquid-tethered nanoparticle hybrid electrolytes comprised of silica nanoparticles densely grafted with imidazolium-based ionic liquid chains are shown to retard lithium dendrite growth in rechargeable batteries with metallic lithium anodes. The electrolytes are demonstrated in full cell studies using both high-energy Li/MoS2 and high-power Li/TiO2 secondary batteries. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. IONIC LIQUIDS DERIVATIVE OF 1Н-IMIDAZOLE AS NOVEL REAGENTS, CATALYSTS AND SOLVENTS

    Directory of Open Access Journals (Sweden)

    V. Sargorovschi

    2010-06-01

    Full Text Available Ionic liquids are becoming widely used in chemical processes. Taking this into account we focus on recent advances in the synthesis and the investigation of 1H-imidazole derived ionic liquids. The fi rst part of this paper focuses on describing the developments in the synthesis and physical properties of 1,3-disubstituted imidazolium salts. The second part describes the application of these unique reagents, as catalysts and solvents in organic chemistry.

  20. Ionic liquid-nanoparticle hybrid electrolytes and their application in secondary lithium-metal batteries

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yingying; Das, Shyamal K.; Moganty, Surya S.; Archer, Lynden A. [School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY (United States)

    2012-08-22

    Ionic liquid-tethered nanoparticle hybrid electrolytes comprised of silica nanoparticles densely grafted with imidazolium-based ionic liquid chains are shown to retard lithium dendrite growth in rechargeable batteries with metallic lithium anodes. The electrolytes are demonstrated in full cell studies using both high-energy Li/MoS{sub 2} and high-power Li/TiO{sub 2} secondary batteries. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Ionic liquid-nanoparticle hybrid electrolytes and their application in secondary lithium-metal batteries.

    Science.gov (United States)

    Lu, Yingying; Das, Shyamal K; Moganty, Surya S; Archer, Lynden A

    2012-08-22

    Ionic liquid-tethered nanoparticle hybrid electrolytes comprised of silica nanoparticles densely grafted with imidazolium-based ionic liquid chains are shown to retard lithium dendrite growth in rechargeable batteries with metallic lithium anodes. The electrolytes are demonstrated in full cell studies using both high-energy Li/MoS(2) and high-power Li/TiO(2) secondary batteries. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. 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....

  3. Bis-methyl imidazolium methylidene bis (trifluoromethanesulfonyl ...

    Indian Academy of Sciences (India)

    A new geminal di-cationic ionic liquid (IL) containing a central cationic unit methylidene capped by a basic functionality (imidazole) is synthesized. The compound was characterized by means of 1 H, 1 3 C, 1 9 F NMR, IR and Raman spectroscopies and its crystal structure is confirmed by single crystal X-ray diffraction ...

  4. 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.

  5. Synthesis and antimicrobial properties of camphorsulfonic acid derived imidazolium salts

    Directory of Open Access Journals (Sweden)

    Mikláš R.

    2014-12-01

    Full Text Available A group of homochiral imidazolium salts bearing hydrophobic camphor derived moiety and ester or amide functional group were synthesized and characterized. The novel imidazolium bromides were tested as antimicrobial and antifungal agents and their minimal inhibitory concentration (MIC was evaluated and compared to clinically used benzalkonium bromide (BAB and carbethopendecinium bromide. The MIC values of amide derivatives 2a and 2b were slightly smaller than those for BAB, indicating their good activity. None of the prepared salts was more effective than carbethopendecinium bromide. The biocidal efficacy of amide derivatives was much higher compared to the ester analogues.

  6. Gamma and heavy ion radiolysis of ionic liquids: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Dhiman, Surajdevprakash B. [Radiation Laboratory, University of Notre Dame, Notre Dame, IN 46556 (United States); Goff, George S. [Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Runde, Wolfgang [Science Programs Office, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); LaVerne, Jay A., E-mail: laverne.1@nd.edu [Radiation Laboratory, University of Notre Dame, Notre Dame, IN 46556 (United States); Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)

    2014-10-15

    A variety of imidazolium, quaternary ammonium, and phosphonium cation based ionic liquids were irradiated with γ-rays, 2–15 MeV protons and 5–20 MeV helium ions in order to examine their relative radiation stability and potential hazards for application in advanced nuclear fuel cycles. Molecular hydrogen production can be taken as an overall indicator of radiation stability, and was found to be considerably lower for the γ-irradiated aromatic imidazolium based compounds when compared to the other aliphatic based media. Increasing the length of the aliphatic side chain increases the H{sub 2} yields for all the compounds examined. Little difference is found in the production of H{sub 2} between the quaternary ammonium and phosphonium based ionic liquids with similar length side chains. Yields of H{sub 2} increase substantially from γ-rays to 5 MeV He ions for the imidazolium based ionic liquids, but little variation with radiation type is observed for the quaternary ammonium and phosphonium based ionic liquids. The imidazolium based ionic liquids show a darkening with increasing dose and the UV–Visible spectra show an increase in absorption from 240 to 400 nm that is probably due to induced changes in the cation. FTIR spectra show little variation with radiolysis, which is consistent with the low H{sub 2} yields. The formation of a new peak at 1658 cm{sup −1} is attributable to the formation of acyclic disubstituted alkene bonds in the irradiated imidazolium based compounds.

  7. Ionic Liquids as Electrolytes for Electrochemical Double-Layer Capacitors: Structures that Optimize Specific Energy.

    Science.gov (United States)

    Mousavi, Maral P S; Wilson, Benjamin E; Kashefolgheta, Sadra; Anderson, Evan L; He, Siyao; Bühlmann, Philippe; Stein, Andreas

    2016-02-10

    Key parameters that influence the specific energy of electrochemical double-layer capacitors (EDLCs) are the double-layer capacitance and the operating potential of the cell. The operating potential of the cell is generally limited by the electrochemical window of the electrolyte solution, that is, the range of applied voltages within which the electrolyte or solvent is not reduced or oxidized. Ionic liquids are of interest as electrolytes for EDLCs because they offer relatively wide potential windows. Here, we provide a systematic study of the influence of the physical properties of ionic liquid electrolytes on the electrochemical stability and electrochemical performance (double-layer capacitance, specific energy) of EDLCs that employ a mesoporous carbon model electrode with uniform, highly interconnected mesopores (3DOm carbon). Several ionic liquids with structurally diverse anions (tetrafluoroborate, trifluoromethanesulfonate, trifluoromethanesulfonimide) and cations (imidazolium, ammonium, pyridinium, piperidinium, and pyrrolidinium) were investigated. We show that the cation size has a significant effect on the electrolyte viscosity and conductivity, as well as the capacitance of EDLCs. Imidazolium- and pyridinium-based ionic liquids provide the highest cell capacitance, and ammonium-based ionic liquids offer potential windows much larger than imidazolium and pyridinium ionic liquids. Increasing the chain length of the alkyl substituents in 1-alkyl-3-methylimidazolium trifluoromethanesulfonimide does not widen the potential window of the ionic liquid. We identified the ionic liquids that maximize the specific energies of EDLCs through the combined effects of their potential windows and the double-layer capacitance. The highest specific energies are obtained with ionic liquid electrolytes that possess moderate electrochemical stability, small ionic volumes, low viscosity, and hence high conductivity, the best performing ionic liquid tested being 1-ethyl-3

  8. Diffusion of 1-ethyl-3-methyl-imidazolium acetate in glucose, cellobiose, and cellulose solutions.

    Science.gov (United States)

    Ries, Michael E; Radhi, Asanah; Keating, Alice S; Parker, Owen; Budtova, Tatiana

    2014-02-10

    Solutions of glucose, cellobiose and microcrystalline cellulose in the ionic liquid 1-ethyl-3-methyl-imidazolium ([C2mim][OAc]) have been examined using pulsed-field gradient (1)H NMR. Diffusion coefficients of the cation and anion across the temperature range 20-70 °C have been determined for a range of concentrations (0-15% w/w) of each carbohydrate in [C2mim][OAc]. These systems behave as an "ideal mixture" of free ions and ions that are associated with the carbohydrate molecules. The molar ratio of carbohydrate OH groups to ionic liquid molecules, α, is the key parameter in determining the diffusion coefficients of the ions. Master curves for the diffusion coefficients of cation, anion and their activation energies are generated upon which all our data collapses when plotted against α. Diffusion coefficients are found to follow an Arrhenius type behavior and the difference in translational activation energy between free and associated ions is determined to be 9.3 ± 0.9 kJ/mol.

  9. Ionic liquids influence on the surface properties of electron beam irradiated wood

    Energy Technology Data Exchange (ETDEWEB)

    Croitoru, Catalin [“Transilvania” University of Brasov, Product Design and Environment Department, 29 Eroilor Str., 500036, Brasov (Romania); Patachia, Silvia, E-mail: st.patachia@unitbv.ro [“Transilvania” University of Brasov, Product Design and Environment Department, 29 Eroilor Str., 500036, Brasov (Romania); Doroftei, Florica; Parparita, Elena; Vasile, Cornelia [“Petru Poni” Institute of Macromolecular Chemistry, Physical Chemistry of Polymers Department, 41A Gr. Ghica Voda Alley, Iasi (Romania)

    2014-09-30

    Highlights: • Wood veneers impregnated with three imidazolium-based ionic liquids and irradiated with electron beam were studied by FTIR-ATR, SEM/EDX, AFM, contact angle and image analysis. • ILs preserve the surface properties of the wood (surface energy, roughness, color) upon irradiation, in comparison with the reference wood, but the surface composition is changed by treatment with IL-s, mainly with 1-butyl-3-methylimidazolium tetrafluoroborate. • Under electron beam irradiation covalent bonding of the imidazolium moiety to wood determines a higher resistance to water penetration and spreading on the surface. - Abstract: In this paper, the influence of three imidazolium-based ionic liquids (1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate and 1-hexyl-3-methylimidazolium chloride) on the structure and surface properties of sycamore maple (Acer pseudoplatanus) veneers submitted to electron beam irradiation with a dose of 50 kGy has been studied by using Fourier transform infrared spectroscopy, as well as image, scanning electron microscopy/SEM/EDX, atomic force microscopy and contact angle analysis. The experimental results have proven that the studied ionic liquids determine a better preservation of the structural features of wood (cellulose crystallinity index and lignin concentration on the surface) as well as some of surface properties such as surface energy, roughness, color upon irradiation with electron beam, in comparison with the reference wood, but surface composition is changed by treatment with imidazolium-based ionic liquids mainly with 1-butyl-3-methylimidazolium tetrafluoroborate. Also, under electron beam irradiation covalent bonding of the imidazolium moiety to wood determines a higher resistance to water penetration and spreading on the surface.

  10. Ionic liquid – Assisted emulsion polymerization of aniline in organic medium

    Energy Technology Data Exchange (ETDEWEB)

    Calheiros, Loan F. [Universidade Federal do Rio de Janeiro, Instituto de Macromoléculas, 21941-598, Rio de Janeiro (Brazil); Soares, Bluma G., E-mail: bluma@metalmat.ufrj.br [Universidade Federal do Rio de Janeiro, PEMM-COPPE, Centro de Tecnologia, 21941-972, Rio de Janeiro (Brazil); Universidade Federal do Rio de Janeiro, Instituto de Macromoléculas, 21941-598, Rio de Janeiro (Brazil); Barra, Guilherme M.O. [Universidade Federal de Santa Catarina, Mechanical Engineering Department, Florianópolis, SC (Brazil); Livi, Sébastien [Université de Lyon, F-69003, Lyon (France); INSA Lyon, F-69621, Villeurbanne (France); CNRS, UMR 5223, Ingénierie des Matériaux Polymères (France)

    2016-08-15

    Polyaniline doped with dodecylbenzene sulfonic acid (PAni.DBSA) with different conductivities and morphologies was prepared by inverted emulsion polymerization, in toluene using ammonium peroxydisulfate as the oxidizing agent, in the presence of two different imidazolium – based ionic liquids, such as, 1-methyl-3-butyl imidazolium tetrafluorate (bmim.BF{sub 4}) and 1-(11-carboxyundecyl)-3-methylimidazolium bromide (mimC{sub 10}COOH.Br). The influence of ionic liquid on the morphology and particle size of formed PAni.DBSA samples was investigated by field emission - scanning electron microscopy (FEG-SEM) and dynamic light scattering (DLS) measurements. Ultraviolet–visible measurements were also employed to confirm the structure of the conducting polymer. PAni.DBSA samples were also characterized by thermogravimetric analysis, cyclic voltammetry and X-ray photoelectron spectroscopy (XPS). PAni.DBSA samples prepared in the presence of ionic liquids have shown improved dispersability in epoxy resin as indicated by optical micrograph. - Highlights: • Imidazolium-based ionic liquids as soft templates for polyaniline synthesis. • PAni with higher conductivity and different morphologies was achieved in the presence of IL. • Good IL/aniline salt interaction resulted in confinement inside PAni particles. • IL confinement confirmed by TGA and XPS analyses. • Excellent dispersability of PAni. DBSA prepared with ionic liquids, in epoxy matrix.

  11. The Inhibition of Aluminum Corrosion in Sulfuric Acid by Poly(1-vinyl-3-alkyl-imidazolium Hexafluorophosphate

    Directory of Open Access Journals (Sweden)

    Paulina Arellanes-Lozada

    2014-08-01

    Full Text Available Compounds of poly(ionic liquids (PILs, derived from imidazole with different alkylic chain lengths located in the third position of the imidazolium ring (poly(1-vinyl-3-dodecyl-imidazolium (PImC12, poly(1-vinyl-3-octylimidazolium (PImC8 and poly(1-vinyl-3-butylimidazolium (PImC4 hexafluorophosphate were synthesized. These compounds were tested as corrosion inhibitors on aluminum alloy AA6061 in diluted sulfuric acid (0.1–1 M H2SO4 by weight loss tests, polarization resistance measurements and inductively coupled plasma optical emission spectroscopy. Langmuir’s isotherms suggested film formation on bare alloy while standard free energy indicated inhibition by a physisorption process. However, compound efficiencies as inhibitors ranked low (PImC12 > PImC8 > PImC4 to reach 61% for PImC12 in highly diluted acidic solution. Apparently, the high mobility of sulfates favored their adsorption in comparison to PILs. The surface film displayed general corrosion, and pitting occurred as a consequence of PILs’ partial inhibition along with a continuous dissolution of defective patchy film on formation. A slight improvement in efficiency was displayed by compounds having high molecular weight and a long alkyl chain, as a consequence of steric hindrance and PIL interactions.

  12. The complex story of a simple Brønsted acid: unusual speciation of HBr in an ionic liquid medium.

    Science.gov (United States)

    Driver, Gordon W; Mutikainen, Ilpo

    2011-11-07

    Crystalline solids, co-existing in equilibrium with the 3-methyl-1H-imidazolium bromohydrogenates(I) ionic liquid, have been characterised by X-ray diffraction analysis. The Brønsted acidic, homo-conjugate [H(2)Br(3)](-) anions presented are discussed in terms of their structure and reactivity, in efforts to advance the understanding of Brønsted acidity in ionic liquid media.

  13. A new imidazolium-embedded C{sub 18} stationary phase with enhanced performance in reversed-phase liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Hongdeng [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Lanzhou Institute of Chemical Physics, Chinese Academy of Science, Lanzhou 730000 (China); Mallik, Abul K. [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Takafuji, Makoto [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Kumamoto Institute for Photo-Electro Organics (Phoenics), Kumamoto 862-0901 (Japan); Liu Xia; Jiang Shengxiang [Lanzhou Institute of Chemical Physics, Chinese Academy of Science, Lanzhou 730000 (China); Ihara, Hirotaka, E-mail: ihara@kumamoto-u.ac.jp [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Kumamoto Institute for Photo-Electro Organics (Phoenics), Kumamoto 862-0901 (Japan)

    2012-08-13

    Highlights: Black-Right-Pointing-Pointer Imidazolium-embedded C{sub 18} stationary phase was prepared and characterized. Black-Right-Pointing-Pointer Enhanced chromatographic selectivity was observed in SiImC{sub 18} column. Black-Right-Pointing-Pointer Seven nucleosides and bases were separated using only water as eluent within 8 min. Black-Right-Pointing-Pointer Multiple-interactions induced by embedded polar imidazolium was investigated. - Abstract: In this paper, a new imidazolium-embedded C{sub 18} stationary phase (SiImC{sub 18}) for reversed-phase high-performance liquid chromatography is described. 1-Allyl-3-octadecylimidazolium bromide ionic liquid compound having a long alkyl chain and reactive groups was newly prepared and grafted onto 3-mercaptopropyltrimethoxysilane-modified silica via a surface-initiated radical-chain transfer addition reaction. The SiImC{sub 18} obtained was characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, diffuse reflectance infrared Fourier transform, and solid-state {sup 13}C and {sup 29}Si cross-polarization/magic angle spinning nuclear magnetic resonance spectroscopy. The selectivity toward polycyclic aromatic hydrocarbons relative to that toward alkylbenzenes exhibited by SiImC{sub 18} was higher than the corresponding selectivity exhibited by a conventional octadecyl silica (ODS) column, which could be explained by electrostatic {pi}-{pi} interaction cationic imidazolium and electron-rich aromatic rings. On the other hand, SiImC{sub 18} also showed high selectivity for polar compounds, which was based on the multiple interaction and retention mechanisms of this phase with different analytes. 1,6-Dinitropyrene and 1,8-dinitropyrene, which form a positional isomer pair of dipolar compounds, were separated successfully with the SiImC{sub 18} phase. Seven nucleosides and bases (i.e. cytidine, uracil, uridine, thymine, guanosine, xanthosine, and adenosine) were separated using only water as

  14. 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.

  15. 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.

  16. Reactions of Sulfur-Containing Organic Compounds and Peptides in 1-Ethyl-3-methyl-imidazolium Acetate.

    Science.gov (United States)

    Baumruck, Andreas C; Tietze, Daniel; Stark, Annegret; Tietze, Alesia A

    2017-07-21

    The neat ionic liquid (IL) [C2mim][OAc] is not just capable of dissolving thiol- and disulfide-containing compounds, but is able to chemically react with them without addition of any catalytic reagent. Through the analysis of four small organic molecules and a cysteine-containing peptide we could postulate a general reaction mechanism. Here, the imidazolium-carbenes preferentially react with the disulfide bond, but not thiol group. Moreover, the imidazole moiety was found to abstract the sulfur atom from the cysteine residue, providing an alternative way to transform Cys residues, which were artificially inserted into a peptide sequence in order to perform native chemical ligation (NCL) of two peptide fragments. Finally, the chemical reaction of [C2mim][OAc] with a cysteine-containing biomolecules can be tuned or even suppressed through the addition of at least 30% of water to the reaction mixture.

  17. 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.

  18. Effect of UV exposure on the surface chemistry of wood veneers treated with ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Patachia, Silvia, E-mail: st.patachia@unitbv.ro [' Transilvania' University of Brasov, Chemistry Department, Eroilor 29 Str., 500036, Brasov (Romania); Croitoru, Catalin, E-mail: c.croitoru@unitbv.ro [' Transilvania' University of Brasov, Chemistry Department, Eroilor 29 Str., 500036, Brasov (Romania); Friedrich, Christian [Albert-Ludwigs-Universitaet Freiburg, Stefan-Meier-Str. 28, Freiburg (Germany)

    2012-07-01

    In this paper, the influence of four types of imidazolium-based ionic liquids (ILs) on the chemical alteration of the surface of wood veneers exposed to 254 nm UV irradiation have been studied by using image analysis, Fourier transform infrared spectroscopy and surface energy calculation. The wood treated with ionic liquids showed better stability to UV light, as demonstrated by the low lignin, carbonyl index and cellulose crystallinity index variation, as well as very small color modification of the surface with the increase of the UV exposure period, by comparing to non-treated wood. The results show that the tested ionic liquids could be effective as UV stabilizers.

  19. 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)

  20. Ferroelectric Polarization Switching Dynamics and Domain Growth of Triglycine Sulfate and Imidazolium Perchlorate

    KAUST Repository

    Ma, He

    2016-04-10

    The weak bond energy and large anisotropic domain wall energy induce many special characteristics of the domain nucleation, growth, and polarization switch in triglycine sulfate (TGS) and imidazolium perchlorate (IM), two typical molecular ferroelectrics. Their domain nucleation and polarization switch are rather slower than those of conventional oxide ferroelectrics, which may be due to the weaker bond energy of hydrogen bond or van der Waals bond than that of ionic bond. These chemical bonds dominate the elastic energy, with the latter being an important component of domain wall energy and playing an important role in domain nucleation and domain growth. The ratio of anisotropic domain wall energy to Gibbs free energy is large in TGS and IM, which allows a favorable domain shape and a special domain evolution under a certain electric field. Therefore, this study not only sheds light on the physical nature but also indicates the application direction for molecular ferroelectrics. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

  1. A green approach for starch modification: Esterification by lipase and novel imidazolium surfactant.

    Science.gov (United States)

    Adak, Sunita; Banerjee, Rintu

    2016-10-05

    Starch being one of the most abundant polysaccharides in nature has been subjected to modification to enhance its applicability. Modification by esterification involves acylation of hydroxyl groups of glucose units to form starch esters. Lipases, as catalysts have emerged as a promising alternative to chemical processes. Although ionic liquids and microwave assisted heating are emerging as green technology yet their use along with lipases for starch modification has not been probed. In the present study esterification of corn starch employing Rhizopus oryzae lipase, microwave irradiation and novel imidazolium surfactants has been attempted. At 80% irradiation, 1:3 starch/oleic acid molar ratio, 150 IU enzyme, and 50μmol of [C16-3-C16im]Br2 maximum degree of substitution (DS=2.75) was attained. The modified starch showed better hydrophobicity and thermoplasticity with corresponding structural changes depicted by FTIR, XRD and SEM. These properties advocate the usefulness of the modified starch in food and biopolymer sectors. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Role of spacer length in interaction between novel gemini imidazolium surfactants and Rhizopus oryzae lipase.

    Science.gov (United States)

    Adak, Sunita; Datta, Sougata; Bhattacharya, Santanu; Banerjee, Rintu

    2015-11-01

    An insight into the effects of new ionic liquid-type gemini imidazolium cationic surfactants on the structure and function of the lipases is of prime importance for their potential application. Changes in the activity, stability and structure of Rhizopus oryzae lipase in the presence of novel gemini surfactants, [C16-3-C16im]Br2 and [C16-12-C16im]Br2 were probed in the present study. Surfactant with shorter spacer length, [C16-3-C16im]Br2 was found to be better in improving the hydrolytic activity and thermal stability of the lipase. For both the surfactants, activation was concentration dependent. CD spectroscopy results showed a decrease in α-helix and an increase in β-sheet content in the presence of these surfactants. A higher structural change observed in presence of [C16-12-C16im]Br2 correlated with lower enzyme activity. Isothermal titration calorimetric studies showed the binding to be spontaneous in nature based on sequential two site binding model. The forces involved in binding were found to differ for the two surfactants proving that the spacer length is an important factor which governs the interaction. These surfactants could be used as promising components both in enzyme modification and media engineering for attaining the desired goals in biocatalytic reactions. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Learning Ionic

    CERN Document Server

    Ravulavaru, Arvind

    2015-01-01

    This book is intended for those who want to learn how to build hybrid mobile applications using Ionic. It is also ideal for people who want to explore theming for Ionic apps. Prior knowledge of AngularJS is essential to complete this book successfully.

  4. Direct exfoliation of natural graphite into micrometre size few layers graphene sheets using ionic liquids.

    Science.gov (United States)

    Wang, Xiqing; Fulvio, Pasquale F; Baker, Gary A; Veith, Gabriel M; Unocic, Raymond R; Mahurin, Shannon M; Chi, Miaofang; Dai, Sheng

    2010-07-07

    Stable high-concentration suspensions (up to 0.95 mg mL(-1)) of non-oxidized few layer graphene (FLG), five or less sheets, with micrometre-long edges were obtained via direct exfoliation of natural graphite flakes in ionic liquids, such as 1-butyl-3-methyl-imidazolium bis(trifluoro-methane-sulfonyl)imide ([Bmim]-[Tf(2)N]), by tip ultrasonication.

  5. Surface and Electrochemical Properties of Polymer Brush-Based Redox Poly(Ionic Liquid).

    Science.gov (United States)

    Bui-Thi-Tuyet, Van; Trippé-Allard, Gaëlle; Ghilane, Jalal; Randriamahazaka, Hyacinthe

    2016-10-26

    Redox-active poly(ionic liquid) poly(3-(2-methacryloyloxy ethyl)-1-(N-(ferrocenylmethyl) imidazolium bis(trifluoromethylsulfonyl)imide deposited onto electrode surfaces has been prepared using surface-initiated atom transfer radical polymerization SI-ATRP. The process starts by electrochemical immobilization of initiator layer, and then methacrylate monomer carrying ferrocene and imidazolium units is polymerized in ionic liquid media via SI-ATRP process. The surfaces analyses of the polymer exhibit a well-defined polymer brushlike structure and confirm the presence of ferrocene and ionic moieties within the film. Furthermore, the electrochemical investigations of poly(redox-active ionic liquid) in different media demonstrate that the electron transfer is not restricted by the rate of counterion migration into/out of the polymer. The attractive electrochemical performance of these materials is further demonstrated by performing electrochemical measurement, of poly(ferrocene ionic liquid), in solvent-free electrolyte. The facile synthesis of such highly ordered electroactive materials based ionic liquid could be useful for the fabrication of nanostructured electrode suitable for performing electrochemistry in solvent free electrolyte. We also demonstrate possible applications of the poly(FcIL) as electrochemically reversible surface wettability system and as electrochemical sensor for the catalytic activity toward the oxidation of tyrosine.

  6. 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.

  7. Electroactive Ionic Soft Actuators with Monolithically Integrated Gold Nanocomposite Electrodes.

    Science.gov (United States)

    Yan, Yunsong; Santaniello, Tommaso; Bettini, Luca Giacomo; Minnai, Chloé; Bellacicca, Andrea; Porotti, Riccardo; Denti, Ilaria; Faraone, Gabriele; Merlini, Marco; Lenardi, Cristina; Milani, Paolo

    2017-06-01

    Electroactive ionic gel/metal nanocomposites are produced by implanting supersonically accelerated neutral gold nanoparticles into a novel chemically crosslinked ion conductive soft polymer. The ionic gel consists of chemically crosslinked poly(acrylic acid) and polyacrylonitrile networks, blended with halloysite nanoclays and imidazolium-based ionic liquid. The material exhibits mechanical properties similar to that of elastomers (Young's modulus ≈ 0.35 MPa) together with high ionic conductivity. The fabrication of thin (≈100 nm thick) nanostructured compliant electrodes by means of supersonic cluster beam implantation (SCBI) does not significantly alter the mechanical properties of the soft polymer and provides controlled electrical properties and large surface area for ions storage. SCBI is cost effective and suitable for the scaleup manufacturing of electroactive soft actuators. This study reports the high-strain electromechanical actuation performance of the novel ionic gel/metal nanocomposites in a low-voltage regime (from 0.1 to 5 V), with long-term stability up to 76 000 cycles with no electrode delamination or deterioration. The observed behavior is due to both the intrinsic features of the ionic gel (elasticity and ionic transport capability) and the electrical and morphological features of the electrodes, providing low specific resistance (<100 Ω cm-2 ), high electrochemical capacitance (≈mF g-1 ), and minimal mechanical stress at the polymer/metal composite interface upon deformation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Modeling the absorption of weak electrolytes and acid gases with ionic liquids using the soft-SAFT approach.

    Science.gov (United States)

    Llovell, F; Marcos, R M; MacDowell, N; Vega, L F

    2012-07-05

    In this work, the solubility of three common pollutants, SO(2), NH(3), and H(2)S, in ionic liquids (ILs) is studied using the soft-SAFT equation of state with relatively simple models. Three types of imidazolium ionic liquids with different anions are described in a transferable manner using the recently published molecular models (Andreu, J. S.; Vega, L. F. J. Phys. Chem. C 2007, 111, 16028; Llovell et al. J. Phys. Chem. B 2011, 115, 4387), whereas new models for SO(2), NH(3), and H(2)S are proposed here. Alkyl-imidazolium ionic liquids with the [PF(6)](-) and [BF(4)](-) anions are considered to be Lennard-Jones chainlike molecules with one associating site in each molecule describing the specific cation-anion interactions. Conversely, the cation and anion forming the imidazolium [Tf(2)N](-) ionic liquids are modeled as a single molecule with three associating sites, taking into account the delocalization of the anion electric charge due to the presence of oxygen groups surrounding the nitrogen of the anion. NH(3) is described with four associating sites: three sites of type H mimicking the hydrogen atoms and one site of type e representing the lone pair of electrons. H(2)S is modeled with three associating sites: two for the sites of type H for the hydrogen atoms and one site of type e for the electronegativity of the sulfur. SO(2) is modeled with two sites, representing the dipole moment of the molecule as an associative interaction. Soft-SAFT calculations with the three models for the pollutants provide very good agreement with the available phase equilibria, enthalpy of vaporization, and heat capacity experimental data. Then, binary mixtures of these compounds with imidazolium-based ionic liquids were calculated in an industrially relevant temperature range. Unlike association interactions between the ionic liquids and the pollutant gases have been explicitly accounted for using an advanced association scheme. A single temperature independent energy binary

  9. Extraction of S- and N-Compounds from the Mixture of Hydrocarbons by Ionic Liquids as Selective Solvents

    Directory of Open Access Journals (Sweden)

    Beata Gabrić

    2013-01-01

    Full Text Available Liquid-liquid extraction is an alternative method that can be used for desulfurization and denitrification of gasoline and diesel fuels. Recent approaches employ different ionic liquids as selective solvents, due to their general immiscibility with gasoline and diesel, negligible vapor pressure, and high selectivity to sulfur- and nitrogen-containing compounds. For that reason, five imidazolium-based ionic liquids and one pyridinium-based ionic liquid were selected for extraction of thiophene, dibenzothiophene, and pyridine from two model solutions. The influences of hydrodynamic conditions, mass ratio, and number of stages were investigated. Increasing the mass ratio of ionic liquid/model fuel and multistage extraction promotes the desulfurization and denitrification abilities of the examined ionic liquids. All selected ionic liquids can be reused and regenerated by means of vacuum evaporation.

  10. Imidazolium-based ionic liquid derivatives for application in electrochromic devices

    Energy Technology Data Exchange (ETDEWEB)

    Surca Vuk, A.; Jovanovski, V.; Jerman, I.; Orel, B. [National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); Pollet-Villard, A. [Joseph Fourier University, BP 53,- 38041 Grenoble cedex 9 (France)

    2008-02-15

    Novel proton-conducting electrolytes were prepared from the sol-gel precursor 1-[3-(trimethoxy-{lambda}{sup 4}-silyl)propyl]imidazole with the addition of either trifluoroacetic or acetic acid. The presence of trimethoxysilyl groups enabled the solvolysis and condensation reactions of silsesquioxane species. IR spectroscopy revealed that more cube-like species formed in the electrolyte prepared from trifluoroacetic acid, while cube- and ladder-like silsesquioxanes were present in the electrolyte with acetic acid. This assignation was independently confirmed by {sup 29}Si NMR analyses revealing the T{sup 3} signals of trisiloxane bonding. IR spectroscopy also pointed to the formation of hydrogen bonding in the latter electrolyte, since the frequencies of the observed bands at 1710, 1409, and 1272 cm{sup -1} approached those of acetic acid. In contrast, the IR bands at 1662, 1204, and 1130 cm{sup -1} confirmed the existence of trifluoroacetate anions in the case when the electrolyte was prepared from trifluoroacetic acid. The presence of free trifluoroacetate anions contributed to the moderately higher specific conductivity of this electrolyte (4.6 x 10{sup -5} S/cm) compared to that of acetic acid (1.6 x 10{sup -5} S/cm). The specific conductivity of the electrolytes could be further increased by the addition of a lithium salt. All electrolytes were employed in electrochromic devices with optically active WO{sub 3} and various inorganic counter-electrodes (CeVO{sub 4}, V{sub 2}O{sub 5}, Ti/V-oxide). Photopic transmittance changes from 30% to 40% were achieved. (author)

  11. tPC-PSAFT modeling of gas solubility in imidazolium-based ionic liquids

    DEFF Research Database (Denmark)

    Karakatsani, Eirini; Economou, Ioannis; Kroon, M. C.

    2007-01-01

    experimental evidence. The new set of parameters is used for the correlation of carbon dioxide solubility in various ILs using a binary interaction parameter, k(ij). The correlated k(ij) values are much lower than the values used previously for the same mixtures (Kroon et al., J. Phys. Chem. B 2006, 110, 9262......). Furthermore, the solubilities of carbon monoxide, oxygen, and trifluoromethane in 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim(+)][PF6(-)]) Are correlated. In all cases, the agreement between tPC-PSAFT correlation and experimental data for mixtures is very good....

  12. Vapor-Liquid Equilibria of Imidazolium Ionic Liquids with Cyano Containing Anions with Water and Ethanol.

    Science.gov (United States)

    Khan, Imran; Batista, Marta L S; Carvalho, Pedro J; Santos, Luís M N B F; Gomes, José R B; Coutinho, João A P

    2015-08-13

    Isobaric vapor-liquid equilibria of 1-butyl-3-methylimidazolium thiocyanate ([C4C1im][SCN]), 1-butyl-3-methylimidazolium dicyanamide ([C4C1im][N(CN)2]), 1-butyl-3-methylimidazolium tricyanomethanide ([C4C1im][C(CN)3]), and 1-ethyl-3-methylimidazolium tetracyanoborate ([C2C1im][B(CN)4]), with water and ethanol were measured over the whole concentration range at 0.1, 0.07, and 0.05 MPa. Activity coefficients were estimated from the boiling temperatures of the binary systems, and the data were used to evaluate the ability of COSMO-RS for describing these molecular systems. Aiming at further understanding the molecular interactions on these systems, molecular dynamics (MD) simulations were performed. On the basis of the interpretation of the radial and spatial distribution functions along with coordination numbers obtained through MD simulations, the effect of the increase of CN-groups in the IL anion in its capability to establish hydrogen bonds with water and ethanol was evaluated. The results obtained suggest that, for both water and ethanol systems, the anion [N(CN)2](-) presents the higher ability to establish favorable interactions due to its charge, and that the ability of the anions to interact with the solvent, decreases with further increasing of the number of cyano groups in the anion. The ordering of the partial charges in the nitrogen atoms from the CN-groups in the anions agrees with the ordering obtained for VLE and activity coefficient data.

  13. Structural evolution of imidazolium-based poly (ionic liquid assemblies during solvent evaporation

    Directory of Open Access Journals (Sweden)

    Q. Ge

    2017-02-01

    –], there is almost no change in inner structures with solvent evaporation except a more ordered lamellar morphology observed in the dried sample. Notably, an interdigitated packing of alkyl tails dominates the lamellar sheets for all dried PIL samples. These results indicate that the design and fabrication of PIL assemblies with ordered structures can be achieved by simply changing counteranion and solvent content, which offers a feasible approach for engineering PIL-based nano-scale functional materials.

  14. 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.

  15. Molecular Simulation of Ionic Polyimides and Composites with Ionic Liquids as Gas-Separation Membranes.

    Science.gov (United States)

    Abedini, Asghar; Crabtree, Ellis; Bara, Jason E; Turner, C Heath

    2017-10-24

    Polyimides are at the forefront of advanced membrane materials for CO2 capture and gas-purification processes. Recently, ionic polyimides (i-PIs) have been reported as a new class of condensation polymers that combine structural components of both ionic liquids (ILs) and polyimides through covalent linkages. In this study, we report CO2 and CH4 adsorption and structural analyses of an i-PI and an i-PI + IL composite containing [C4mim][Tf2N]. The combination of molecular dynamics (MD) and grand canonical Monte Carlo (GCMC) simulations is used to compute the gas solubility and the adsorption performance with respect to the density, fractional free volume (FFV), and surface area of the materials. Our results highlight the polymer relaxation process and its correlation to the gas solubility. In particular, the surface area can provide meaningful guidance with respect to the gas solubility, and it tends to be a more sensitive indicator of the adsorption behavior versus only considering the system density and FFV. For instance, as the polymer continues to relax, the density, FFV, and pore-size distribution remain constant while the surface area can continue to increase, enabling more adsorption. Structural analyses are also conducted to identify the nature of the gas adsorption once the ionic liquid is added to the polymer. The presence of the IL significantly displaces the CO2 molecules from the ligand nitrogen sites in the neat i-PI to the imidazolium rings in the i-PI + IL composite. However, the CH4 molecules move from the imidazolium ring sites in the neat i-PI to the ligand nitrogen atoms in the i-PI + IL composite. These molecular details can provide critical information for the experimental design of highly selective i-PI materials as well as provide additional guidance for the interpretation of the simulated adsorption systems.

  16. An efficient and green sonochemical synthesis of some new eco-friendly functionalized ionic liquids

    Directory of Open Access Journals (Sweden)

    Mouslim Messali

    2014-01-01

    Full Text Available Considerable stress to replace a lot of volatile organic compounds which were used as solvents in synthetic organic chemistry has been done for many chemical industries. A suitable solution for these problems is found by using the ionic liquids as a clean medium of working and avoiding the solvent effect. The present work describes a facile and green ultrasound-assisted procedure as an environmentally friendly alternative to traditional methods for the preparation of a series of 26 new functionalized imidazolium-based ionic liquids. Their structures were characterized by FT-IR, 1H, 13C, 11B, 19F, 31P NMR and mass spectra.

  17. Capillary electrophoretic analysis of neutral carbohydrates using ionic liquids as background electrolytes.

    Science.gov (United States)

    Vaher, Merike; Koel, Mihkel; Kazarjan, Jana; Kaljurand, Mihkel

    2011-04-01

    In this study, ionic liquids (ILs) as BGE additives were applied for the analysis of neutral carbohydrates in CE. The ILs served primarily as chromophores for indirect UV detection. The influence of imidazolium-based ionic liquids on the separation, detection limits and mobility of underivatized neutral carbohydrates was investigated. BGEs consisting of 10-50  mM of ILs at pH 12.4 without other additives provided fast separation of neutral sugars. This method was used to determine sucrose, glucose and fructose in certain vegetable juices. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Characterization of surface confined ionic liquid stationary phases: impact of cation revisited.

    Science.gov (United States)

    VanMiddlesworth, Bradley J; Stalcup, Apryll M

    2014-10-17

    Modification of the Linear Solvation Energy Relationship (LSER) equation to account for ionic interactions in the retention of ionizable compounds has enabled the elucidation in the effect of the imidazolium cation identity on retention. Three Surface Confined Ionic Liquid stationary phases were synthesized from an octylbromide phase on silica: 1-octyl-3-methylimidazolium bromide (MIM), 1-octyl-3-butylimidazolium bromide (BIM), and 1-octyl-3-benzylimidazolium bromide (BzIM). These phases were probed via a 35 analyte probe set, including 6 phenolic acids, 5 anilinic bases, and 2 pyridinic bases, and the resulting column parameters compared with previously reported interactions of ionic liquids or Surface Confined Ionic Liquids. The correlation between experimental and calculated retention for the conventional, 6-parameter LSER equation was very poor: r(2)=0.64 (MIM), 0.60 (BIM), and 0.62 (BzIM). By accounting for the ionic interactions between stationary phase and analytes, linearity for the modified, 8 parameter LSER equation was significantly improved to r(2)=0.997 (MIM), 0.996 (BIM), and 0.997 (BzIM). The primary difference between cation identities is within the retention of acids where BIM>BzIM>MIM. We conjecture that the accessibility of bulky, acidic analytes to the on-top interaction of the imidazolium ring is the major contributor to increased anion retention. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Gemini imidazolium surfactants: synthesis and their biophysiochemical study.

    Science.gov (United States)

    Kamboj, Raman; Singh, Sukhprit; Bhadani, Avinash; Kataria, Hardeep; Kaur, Gurcharan

    2012-08-21

    New gemini imidazolium surfactants 9-13 have been synthesized by a regioselective epoxy ring-opening reaction under solvent-free conditions. The surface properties of these new gemini surfactants were evaluated by surface tension and conductivity measurements. These surfactants have been found to have low critical micelle concentration (cmc) values as compared to other categories of gemini cationic surfactants and also showed the tendency to form premicellar aggregates in solution at sufficiently low concentration below their cmc values. The thermal degradation of these surfactants was determined by thermograviometry analysis (TGA). These new cationic surfactants have a good DNA binding capability as determined by agarose gel electrophoresis and ethidium bromide exclusion experiments. They have also been found to have low cytotoxicity by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay on the C6 glioma cell line.

  20. Ionic liquids as mobile phase additives for feasible assay of naphazoline in pharmaceutical formulation by HPTLC-UV-densitometric method.

    Science.gov (United States)

    Marszałł, Michał Piotr; Sroka, Wiktor Dariusz; Balinowska, Aleksandra; Mieszkowski, Dominik; Koba, Marcin; Kaliszan, Roman

    2013-07-01

    A specific and reliable high-performance thin layer chromatography method with densitometry detection has been developed for the determination of naphazoline nitrate in nasal drops. The best separation of the basic analyte, without spot tailing, was achieved by using a mobile phase composed of acetonitrile-water (60:40, v/v), adding 1.5 % (v/v) imidazolium-class ionic liquid and covering the plates with a stationary phase based on RP-18 with F254S (10 × 20 cm). The presented results confirm that imidazolium tetrafluoroborate ionic liquids are efficient suppressors of free silanols, which are considered to be responsible for troublesome and irreproducible chromatographic determinations of basic compounds. The developed chromatographic system was found to be convenient in use and to provide a repeatable assay of naphazoline nitrate in nasal drops, which could not be obtained with the use of standard silanol suppressing mobile phase additives such as triethylamine or dimethyloctylamine.

  1. Highly effective ionic liquids for biodiesel production from waste vegetable oils

    Directory of Open Access Journals (Sweden)

    Fathy A. Yassin

    2015-03-01

    Full Text Available As conventional energy sources deplete, the need for developing alternative energy resources which are environment friendly becomes more imperative. Vegetable oils are attracting increased interest in this purpose. The methanolysis of vegetable oil to produce a fatty acid methyl ester (FAME, i.e., biodiesel fuel was catalyzed by commercial ionic liquid and its chloride modification. The imidazolium chloride ionic liquid was frequently chosen for the synthesis of biodiesel. The dual-functionalized’ ionic liquid is prepared by a direct combination reaction between imidazolium cation and various metal chlorides such as CoCl2, CuCl2, NiCl2, FeCl3 and AlCl3. Imidazolium tetrachloroferrate was proved to be a selective catalyst for the methanolysis reaction at a yield of 97% when used at 1:10, catalyst: oil ratio for 8 h at 55 °C. Operational simplicity, reusability of the used catalyst for 8 times at least, high yields and no saponification are the key features of this methodology. The dynamic viscosity and density of the upgraded vegetable oil decreased from 32.1 cP and 0.9227 g/cm3 to 10.2 cP and 0.9044 g/cm3 respectively, compared to those of the base vegetable oil. The objective of this study was the synthesis and characterization of biodiesel using commercial ionic liquid and its chloride modification. The ionic liquid catalysts were characterized using FTIR, Raman spectroscopy, DSC, TG and UV.

  2. Conjugated Polyelectrolytes with Imidazolium Solubilizing Groups. Properties and Application to Photodynamic Inactivation of Bacteria.

    Science.gov (United States)

    Parthasarathy, Anand; Pappas, Harry C; Hill, Eric H; Huang, Yun; Whitten, David G; Schanze, Kirk S

    2015-12-30

    This article reports an investigation of the photophysical properties and the light- and dark-biocidal activity of two poly(phenyleneethynylene) (PPE)-based conjugated polyelectrolytes (CPEs) bearing cationic imidazolium solubilizing groups. The two polymers feature the same PPE-type backbone, but they differ in the frequency of imidazoliums on the chains: PIM-4 features two imidazolium units on every phenylene repeat, whereas PIM-2 contains two imidazolium units on every other phenylene unit. Both polymers are very soluble in water and polar organic solvents, but their propensity to aggregate in water differs with the density of the imidazolium units. The polymers are highly fluorescent, and they exhibit the amplified quenching effect when exposed to a low concentration of anionic electron-acceptor anthraquinone disulfonate. The CPEs are also quenched by a relatively low concentration of pyrophosphate by an aggregation-induced quenching mechanism. The biocidal activity of the cationic imidazolium CPEs was studied against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria in the dark and under blue-light illumination. Both polymers are effective biocides, exhibiting greater than 3 log kill with 30-60 min of light exposure at concentrations of ≤10 μg mL(-1).

  3. Ionic liquids as recyclable and separable reaction media in Rh-catalyzed decarbonylation of aromatic and aliphatic aldehydes

    DEFF Research Database (Denmark)

    Malcho, Phillip; Garcia-Suarez, Eduardo J.; Riisager, Anders

    2014-01-01

    Ionic liquids (ILs) have been applied as recyclable reaction media in the decarbonylation of aldehydes in the presence of a rhodium-phosphine complex catalyst. The performance of several new catalytic systems based on imidazolium-based ILs and [Rh(dppp)2]Cl (dppp: 1,3-diphenylphosphinopropane) were...... as a biphasic system with the product allowing recovery and reuse of the employed catalyst....

  4. Polarizability effects on the structure and dynamics of ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Cavalcante, Ary de Oliveira, E-mail: arycavalcante@ufam.edu.br [Institute of Chemistry, University of Campinas – UNICAMP, Cx. P. 6154, Campinas, SP 13084-862 (Brazil); Departamento de Química, Universidade Federal do Amazonas, Av. Rodrigo Octávio, 6200, Coroado, Manaus, AM (Brazil); Ribeiro, Mauro C. C. [Laboratório de Espectroscopia Molecular, Instituto de Química, Universidade de São Paulo, São Paulo, SP C.P. 26077, 05513 970 São Paulo, SP (Brazil); Skaf, Munir S. [Institute of Chemistry, University of Campinas – UNICAMP, Cx. P. 6154, Campinas, SP 13084-862 (Brazil)

    2014-04-14

    Polarization effects on the structure and dynamics of ionic liquids are investigated using molecular dynamics simulations. Four different ionic liquids were simulated, formed by the anions Cl{sup −} and PF{sub 6}{sup −}, treated as single fixed charge sites, and the 1-n-alkyl-3-methylimidazolium cations (1-ethyl and 1-butyl-), which are polarizable. The partial charge fluctuation of the cations is provided by the electronegativity equalization model (EEM) and a complete parameter set for the cations electronegativity (χ) and hardness (J) is presented. Results obtained from a non-polarizable model for the cations are also reported for comparison. Relative to the fixed charged model, the equilibrium structure of the first solvation shell around the imidazolium cations shows that inclusion of EEM polarization forces brings cations closer to each other and that anions are preferentially distributed above and below the plane of the imidazolium ring. The polarizable model yields faster translational and reorientational dynamics than the fixed charges model in the rotational-diffusion regime. In this sense, the polarizable model dynamics is in better agreement with the experimental data.

  5. Ionic Liquid Assisted Exfoliation of Layered Magnesium Diboride

    Science.gov (United States)

    Ratnam, Devina; Das, Saroj Kumar; Jasuja, Kabeer

    2017-08-01

    The discovery of graphene showcased anability to isolate atomic thin sheet from layered graphite, and presented a precedent to the scientific community for exploring a similar possibility in other layered materials. Magnesium diboride (MgB2), which has metal atoms sandwiched in between boron honeycomb planes, represents an ionic layered material isostructural to intercalated graphite. We show that ultrasonication of MgB2 in ionic liquid (1-butyl-3-methyl imidazolium tetrafluoroborate)results in a stable dispersion of few-layer-thick boron based nanosheets. Furthermore, these nanosheets (∼3-6 µm wide, ∼2 nm thick) are found to exhibit an optical band-gap of ∼3.3eV alongwith excitation wavelength dependent photoluminescence.

  6. Ion shape effect on dynamics of ionic liquids

    Science.gov (United States)

    Liu, Hongjun; Maginn, Edward

    2012-02-01

    Ionic liquids (ILs) are a group of salts composing of an organic cation and organic or inorganic anion with melting points below 100 ^oC and have many suitable properties, such as negligible vapor pressure, low flammability, high ionic conductivity and high thermal stability for various applications. Moreover, a great number of ILs with a variety of physical and chemical properties can be synthesized from a combination of different cations (most differently substituted imidazolium, pyridinium, and quaternary ammonium or phosphonium ions) and anions. One can judiciously select from a multitude of ILs to suit a specific application, where the concept of designer solvent comes from. To expedite the development process of target ILs, it is crucial to understand the relationship between ion shape and dynamics of ILs. We studied a wide range of ILs with different ion shape pairings and found the planar-planar paired ILs have a better dynamics as a whole.

  7. 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.

  8. Fabrication of dendritic gold nanoparticles by use of an ionic polymer template.

    Science.gov (United States)

    Zhang, Jichun; Meng, Lingjie; Zhao, Dongbin; Fei, Zhaofu; Lu, Qinghua; Dyson, Paul J

    2008-03-18

    A facile method for the fabrication of dendritic gold nanoparticles (NPs) by use of an ionic polymer template has been developed. In situ generation of an imidazolium-based (cationic) polymer, poly[1-methyl-3-(4-vinylbenzyl)imidazolium], with AuCl4- counteranions is achieved by addition of HAuCl4 into a solution containing poly[1-methyl-3-(4-vinylbenzyl)imidazolium chloride]. Subsequent reduction with NaBH4 in water or in a mixture of ethanol and water affords various NPs depending on the conditions, including large dendritic gold NPs that have been analyzed by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and selected area electron diffraction (SAED). The structures of the dendritic gold NPs were found to depend on the ethanol concentration. Scanning electron microscopy (SEM) images of the ionic polymer reveal that the solvent used to deposit the polymer strongly influences its structure and may be correlated to the structure of the resulting NPs.

  9. Synthesis and application of dual functionalized task specific ionic liquid for bamboo dissolution

    Directory of Open Access Journals (Sweden)

    Hameed Sultan Nor Shahroon

    2017-01-01

    Full Text Available A new class of dual functionalized imidazolium based ionic liquid (IL namely 3-(2-cyano-ethyl-1-(2-ethoxy-ethyl-3-imidazolium bromide [CNEIM][Br], was synthesized and characterized to study their potential in bamboo dissolution. The chemical structure for the IL was characterized using NMR (1H and 13C. Thermal properties, surface morphology and functional group of the native bamboo and IL treated bamboo were analyzed by Thermal Gravimetric Anaylysis (TGA, Scanning Electron Microscopy (SEM and Fourier Transform Infrared Spectroscopy (FTIR respectively. The new IL was able to dissolve up to 5wt% of bamboo biomass within 48 hours and 100°C.

  10. 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.

  11. 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.

  12. 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.

  13. Olefins hydro-formylation catalysed by rhodium complexes using ionic liquids; Hydroformylation des olefines par les complexes du rhodium dans les liquides ioniques

    Energy Technology Data Exchange (ETDEWEB)

    Favre, F.

    2000-10-26

    Biphasic long chain olefins hydro-formylation catalysed by rhodium complexes using ionic liquids allows a selective reaction and an easy separation of the products from the catalyst. This study reports the synthesis of ionic liquids that were used as the catalyst's solvent. Their physical and chemical properties (melting point, solubility of organic substrates) can be varied with the structure of the organic cation (imidazolium, pyridinium, pyrrolydinium) and with its substituents (nature, length, number). It depends also on the nature of the inorganic anion (hexa-fluoro-phosphate, tetrafluoroborate, tri-fluoro-acetate, triflate, bistriflylamidure...). The use of phosphorus ligands bearing ionic functions proved to be efficient to maintain the onerous rhodium catalyst in the ionic liquid phase. Phosphines, phosphites and phosphinites including anionic (sulfonate, carboxylate) or cationic (imidazolium, pyridinium, guanidinium, phosphonium) groups have been synthesised. Finally, the influences of the ligand and of the ionic liquid on the catalytic system performances are described. Selectivities in aldehydes and reaction rates proved to be highly dependent on the nature of the ligand and of the ionic liquid. The different possibilities of recycling the ionic phase containing the rhodium catalyst have been also studied. (author)

  14. Preparation, characterization and thermal stability of bentonite modified with bis-imidazolium salts

    Energy Technology Data Exchange (ETDEWEB)

    Makhoukhi, B., E-mail: benamarmakh@yahoo.fr [Laboratory of Separation and Purification Technologies, Department of Chemistry, Tlemcen University, Box 119, Tlemcen (Algeria); Villemin, D. [Laboratoire de Chimie Moléculaire et Thio-organique, UMR CNRS 6507, INC3M, FR 3038, ENSICAEN and Université de Caen, 14050 Caen (France); Didi, M.A. [Laboratory of Separation and Purification Technologies, Department of Chemistry, Tlemcen University, Box 119, Tlemcen (Algeria)

    2013-02-15

    Sodium bentonite was modified with several organic bis-imidazolium salts. Organoclays with water soluble surfactants were prepared by the traditional cation exchange reaction. The bis-imidazolium-bentonites were characterized by Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction analysis (PXRD) and thermogravimetric analysis (TGA). The effect of chemical composition and molecular weight of the salts on the thermal stability and basal spacing were evaluated. The bis-imidazolium-bentonites showed enhanced thermal stability (300–400 °C) and may be potentially useful materials for melt processing of polymer/layered silicates nanocomposites. - Highlights: ► Geometry and volume of the molecule influence on interlayer spacing of modified bentonites. ► The intercalation increases with molecule length. ► The modified bentonites have an appreciably higher thermal stability.

  15. Imidazolium-Based Polymeric Materials as Alkaline Anion-Exchange Fuel Cell Membranes

    Science.gov (United States)

    Narayan, Sri R.; Yen, Shiao-Ping S.; Reddy, Prakash V.; Nair, Nanditha

    2012-01-01

    Polymer electrolyte membranes that conduct hydroxide ions have potential use in fuel cells. A variety of polystyrene-based quaternary ammonium hydroxides have been reported as anion exchange fuel cell membranes. However, the hydrolytic stability and conductivity of the commercially available membranes are not adequate to meet the requirements of fuel cell applications. When compared with commercially available membranes, polystyrene-imidazolium alkaline membrane electrolytes are more stable and more highly conducting. At the time of this reporting, this has been the first such usage for imidazolium-based polymeric materials for fuel cells. Imidazolium salts are known to be electrochemically stable over wide potential ranges. By controlling the relative ratio of imidazolium groups in polystyrene-imidazolium salts, their physiochemical properties could be modulated. Alkaline anion exchange membranes based on polystyrene-imidazolium hydroxide materials have been developed. The first step was to synthesize the poly(styrene-co-(1-((4-vinyl)methyl)-3- methylimidazolium) chloride through a free-radical polymerization. Casting of this material followed by in situ treatment of the membranes with sodium hydroxide solutions provided the corresponding hydroxide salts. Various ratios of the monomers 4-chloromoethylvinylbenzine (CMVB) and vinylbenzine (VB) provided various compositions of the polymer. The preferred material, due to the relative ease of casting the film, and its relatively low hygroscopic nature, was a 2:1 ratio of CMVB to VB. Testing confirmed that at room temperature, the new membranes outperformed commercially available membranes by a large margin. With fuel cells now in use at NASA and in transportation, and with defense potential, any improvement to fuel cell efficiency is a significant development.

  16. Synthesis, Characterization and Catalytic Polymerization of N-Methyl Imidazolium Phosphotungstic Catalyst

    Directory of Open Access Journals (Sweden)

    Dianyu Chen

    2015-11-01

    Full Text Available N-methyl imidazolium phosphotungstic salt has been synthesized and used as a special catalyst for photopolymerization of vinyl monomers. This is a fast and smooth reaction, and high molecular weight polymers with narrow polydispersity are obtained within 60 min. The compound was structurally characterized by elemental analysis, IR spectroscopy, and 1H NMR spectroscopy. The electrochemical property is determined on a CHI 660 electrochemistry workstation. The polymerization initiated by N-methyl imidazolium phosphotungstic salt showed controlling characteristics, the catalyst can be easily isolated from polymer product, and reused for at least 10 times.

  17. Neighbor-directed histidine N(τ) alkylation. A route to imidazolium-containing phosphopeptide macrocycles

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Wen-Jian [National Cancer Inst., Frederick, MD (United States); Park, Jung-Eun [National Cancer Inst., Bethesda, MD (United States); Grant, Robert [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Lai, Christopher C. [National Cancer Inst., Frederick, MD (United States); Kelley, James A. [National Cancer Inst., Frederick, MD (United States); Yaffe, Michael B. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Lee, Kyung S. [National Cancer Inst., Bethesda, MD (United States); Burke, Terrence R. [National Cancer Inst., Frederick, MD (United States)

    2015-07-07

    Our recently discovered, selective, on-resin route to N(τ)-alkylated imidazolium-containing histidine residues affords new strategies for peptide mimetic design. In this, we demonstrate the use of this chemistry to prepare a series of macrocyclic phosphopeptides, in which imidazolium groups serve as ring-forming junctions. These cationic moieties subsequently serve to charge-mask the phosphoamino acid group that directed their formation. Furthermore, neighbor-directed histidine N(τ)-alkylation opens the door to new families of phosphopeptidomimetics for use in a range of chemical biology contexts.

  18. 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.

  19. Ionic Liquids as Solvents for Rhodium and Platinum Catalysts Used in Hydrosilylation Reaction

    Directory of Open Access Journals (Sweden)

    Witold Zielinski

    2016-08-01

    Full Text Available A group of imidazolium and pyridinium based ionic liquids has been synthetized, and their ability to dissolve and activate the catalysts used in hydrosilylation reaction of 1-octane and 1,1,1,3,5,5,5-heptamethyltrisiloxane was investigated. An organometallic catalyst as well as inorganic complexes of platinum and rhodium dissolved in ionic liquids were used, forming liquid solutions not miscible with the substrates or with the products of the reaction. The results show that application of such a simple biphasic catalytic system enables reuse of ionic liquid phase with catalysts in multiple reaction cycles reducing the costs and decreasing the amount of catalyst needed per mole of product.

  20. CO2 Capture in Ionic Liquids: A Review of Solubilities and Experimental Methods

    Directory of Open Access Journals (Sweden)

    Elena Torralba-Calleja

    2013-01-01

    Full Text Available The growing concern of climate change and global warming has in turn given rise to a thriving research field dedicated to finding solutions. One particular area which has received considerable attention is the lowering of carbon dioxide emissions from large-scale sources, that is, fossil fuel power. This paper focuses on ionic liquids being used as novel media for CO2 capture. In particular, solubility data and experimental techniques are used at a laboratory scale. Cited CO2 absorption data for imidazolium-, pyrrolidinium-, pyridinium-, quaternary-ammonium-, and tetra-alkyl-phosphonium-based ionic liquids is reviewed, expressed as mole fractions (X of CO2 to ionic liquid. The following experimental techniques are featured: gravimetric analysis, the pressure drop method, and the view-cell method.

  1. 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.

  2. 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.

  3. Shape-Memory Behavior of Polylactide/Silica Ionic Hybrids

    KAUST Repository

    Odent, Jérémy

    2017-03-27

    Commercial polylactide (PLA) was converted and endowed with shape-memory properties by synthesizing ionic hybrids based on blends of PLA with imidazolium-terminated PLA and poly[ε-caprolactone-co-d,l-lactide] (P[CL-co-LA]) and surface-modified silica nanoparticles. The electrostatic interactions assist with the silica nanoparticle dispersion in the polymer matrix. Since nanoparticle dispersion in polymers is a perennial challenge and has prevented nanocomposites from reaching their full potential in terms of performance we expect this new design will be exploited in other polymers systems to synthesize well-dispersed nanocomposites. Rheological measurements of the ionic hybrids are consistent with the formation of a network. The ionic hybrids are also much more deformable compared to the neat PLA. More importantly, they exhibit shape-memory behavior with fixity ratio Rf ≈ 100% and recovery ratio Rr = 79%, for the blend containing 25 wt % im-PLA and 25 wt % im-P[CL-co-LA] and 5 wt % of SiO2–SO3Na. Dielectric spectroscopy and dynamic mechanical analysis show a second, low-frequency relaxation attributed to strongly immobilized polymer chains on silica due to electrostatic interactions. Creep compliance tests further suggest that the ionic interactions prevent permanent slippage in the hybrids which is most likely responsible for the significant shape-memory behavior observed.

  4. Ultraviolet Photoionization Efficiency of the Vaporized Ionic Liquid 1-Butyl-3-Methylimidazolium Tricyanomethanide: Direct Detection of the Intact Ion Pair (Post Print)

    Science.gov (United States)

    2012-09-21

    papers were published on the subject, whereas in 2010, over 6000 papers were published [SciFinder results searching for the concept “ionic liquid” (August...not limited to, ammonium, imidazolium, triazolium, tetrazolium, and phosphonium ions. Common anions include the halide , nitrate, dicyanamide...are more acidic, and those ILs have been termed “protic” ILs.9 In general, protic ILs have lower thermal stability than ILs with alkyl substituents on

  5. 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.

  6. The role of association of ions in ionic liquid/molecular solvent mixtures on metal extraction.

    Science.gov (United States)

    Andanson, J-M; Papaiconomou, N; Cable, P-A; Traïkia, M; Billard, I; Husson, P

    2017-11-01

    Several mixtures of butyl acetate (BA) and an ionic liquid (1-methyl-3-octylpyrrolidinium bis(trifluoromethylsulfonyl)imide, [C1C8Pyrro][NTf2], 1-octyl-pyridinium bis(trifluoromethylsulfonyl)imide, [C8Pyr][NTf2], 1-butyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide, [C1C4Im][NTf2] or 1-octyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide, [C1C8Im][NTf2]) have been characterized by measuring density, viscosity and conductivity, from pure BA to pure ILs at 298.15 K. The ionicity of these mixtures has been determined on the basis of electrical conductivity and NMR spectroscopy. IR spectra of these mixtures were used to examine the interactions between ions. In parallel, Pt(iv) was extracted from the acidic aqueous phase towards mixtures of BA and [C1C8Im][NTf2] over the entire composition range. A drastic modification in the distribution coefficient of Pt(iv) was observed at ca xAB = 0.8. A drop was also observed in the ionicity of the extracting phase (IL + BA) at a similar composition. The variation of the distribution coefficient is ascribed to changes in the interactions in the mixtures, which in turn could induce changes in the extraction mechanism.

  7. 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.

  8. Combined main-chain/side-chain ionic liquid crystalline polymer based on ‘jacketing’ effect: Design, synthesis, supra-molecular self-assembly and photophysical properties

    Directory of Open Access Journals (Sweden)

    L. Weng

    2015-06-01

    Full Text Available Reasonably fabricating ordered structures of ionic polymers is very important for the development of novel functional materials. By combining the ions and liquid cry stalline polymer, we successfully designed and synthesized a series of novel combined main-chain/side-chain ionic liquid crystalline polymer (MCSC-ILCPs containing imidazolium groups and different counter-anions, poly (2,5-bis{[6-(4-butoxy-4'-imidazolium biphenylhexyl]oxycarbonyl}styrene salts poly(BImBHCS-X with the following types of counter-anions (Br¯, BF4¯, PF6¯ and TFSI¯. Combined technologies confirmed the chemical structures of the monomers and polymers with imidazolium cation and different counter-anions. Differential scanning calorimetry (DSC, polarized light microscopy (PLM and one- and two-dimensional wide-angle X-ray diffraction (1D and 2D WAXD results illustrated that the LC structures and the transitions of ordered structures depended on the nature of the counter-anion employed. The polymers with Br¯ and BF4¯ counter-anions exhibited smectic A (SmA LC behavior below the isotropic temperature. The another one, poly(BImBHCS–TFSI with the large volume of the TFSI¯ anion destroyed the packing of the LC ordered structure resulting in an amorphous structure. The photophysical properties of the polymers prepared can be adjusted by tuning the ionic interaction of the polymers by switching the counter-anion.

  9. Effect of water on the structure of a prototype ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Borodin, Oleg; Price, David L.; Aoun, Bachir; González, Miguel A.; Hooper, Justin B.; Kofu, Maiko; Kohara, Shinji; Yamamuro, Osamu; Saboungi, Marie-Louise

    2016-05-26

    The influence of water on the structure of a prototype ionic liquid (IL) 1-octyl-3-methyimidazolium tetrafluoroborate (C8mimBF4) is examined in the IL-rich regime using high-energy x-ray diffraction (HEXRD) and molecular dynamics (MD) simulations. A many-body polarizable force field APPLE&P was developed for C8mimBF4 water mixture. It predicts structure factors of pure IL and IL-water mixture in excellent agreement with the HEXRD experiments. The MD results provide detailed insights into the structural changes from the partial structure factors, 2-D projections of the simulation box and 3-D distribution functions. Water partitioning with IL and its competition with BF4- for complexing the imidazolium rings was examined. The added water molecules occupy a diffuse coordination shell around the imidazolium ring but are not present around the alkyl tail. The strong coordination of the fluorine atoms of the BF4- anions to the imidazolium ring is not significantly changed by the addition of water. These results are consistent with the very small differences in the average structure between the pure IL and the mixture.

  10. Imidazolium-based Block Copolymers as Solid-State Separators for Alkaline Fuel Cells and Lithium Ion Batteries

    Science.gov (United States)

    Nykaza, Jacob Richard

    In this study, polymerized ionic liquid (PIL) diblock copolymers were explored as solid-state polymer separators as an anion exchange membrane (AEM) for alkaline fuel cells AFCs and as a solid polymer electrolyte (SPE) for lithium-ion batteries. Polymerized ionic liquid (PIL) block copolymers are a distinct set of block copolymers that combine the properties of both ionic liquids (e.g., high conductivity, high electrochemical stability) and block copolymers (e.g., self-assembly into various nanostructures), which provides the opportunity to design highly conductive robust solid-state electrolytes that can be tuned for various applications including AFCs and lithium-ion batteries via simple anion exchange. A series of bromide conducting PIL diblock copolymers with an undecyl alkyl side chain between the polymer backbone and the imidazolium moiety were first synthesized at various compositions comprising of a PIL component and a non-ionic component. Synthesis was achieved by post-functionalization from its non-ionic precursor PIL diblock copolymer, which was synthesized via the reverse addition fragmentation chain transfer (RAFT) technique. This PIL diblock copolymer with long alkyl side chains resulted in flexible, transparent films with high mechanical strength and high bromide ion conductivity. The conductivity of the PIL diblock copolymer was three times higher than its analogous PIL homopolymer and an order of magnitude higher than a similar PIL diblock copolymer with shorter alkyl side chain length, which was due to the microphase separated morphology, more specifically, water/ion clusters within the PIL microdomains in the hydrated state. Due to the high conductivity and mechanical robustness of this novel PIL block copolymer, its application as both the ionomer and AEM in an AFC was investigated via anion exchange to hydroxide (OH-), where a maximum power density of 29.3 mW cm-1 (60 °C with H2/O2 at 25 psig (172 kPa) backpressure) was achieved. Rotating disk

  11. N, N′-Olefin functionalized Bis-Imidazolium Pd (II) chloride N ...

    Indian Academy of Sciences (India)

    N, N′-Olefin functionalized Bis-Imidazolium Pd(II) chloride N-Heterocyclic carbene complex builds a supramolecular framework and shows catalytic efficacy for `C–C' coupling reactions. Gourisankar Roymahapatra Tapastaru Samanta Saikat Kumar Seth Ambikesh Mahapatra Shyamal Kumar Chattopadhyay Joydev Dinda.

  12. Silver(I) and copper(II)-imidazolium carboxylates: Efficient catalysts ...

    Indian Academy of Sciences (India)

    GANESAN PRABUSANKAR

    Copper(II); Silver(I); Coordination polymer; Imidazolium ion; Ullmann coupling. 1. ... dination polymers. These newly prepared catalysts are highly active towards Ullmann reaction. 2. Experimental. 2.1 Materials and methods. The solvents were purchased from commercial ..... The thermal stability of 1 and 2 was analysed.

  13. Systems with ionic liquids: Measurement of VLE and {gamma}{sup {infinity}} data and prediction of their thermodynamic behavior using original UNIFAC, mod. UNIFAC(Do) and COSMO-RS(Ol)

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Ryo [Carl von Ossietzky Universitaet Oldenburg, Technische Chemie, D-26111 Oldenburg (Germany); Gmehling, Juergen [Carl von Ossietzky Universitaet Oldenburg, Technische Chemie, D-26111 Oldenburg (Germany)]. E-mail: gmehling@tech.chem.uni-oldenburg.de

    2005-06-15

    Vapor-liquid equilibria (VLE) for six systems at 353K and activity coefficients at infinite dilution ({gamma}{sup {infinity}}) for various solutes (alkanes, alkenes, cycloalkanes, cycloalkenes, aromatics, alcohols, ketones, esters, ethers, and water) in the ionic liquids; 1-ethyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide [EMIM][BTI], 1-hexyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide [HMIM][BTI], 1-octyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide [OMIM][BTI], and 1-butyl-1-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)imide [BMPYR][BTI] have been determined in the temperature range from (303 to 333)K. Additionally, {gamma}{sub i}{sup {infinity}} were measured for seven solutes in the binary mixture of [EMIM][BTI] and [BMIM][BTI]. Furthermore the densities of the investigated ionic liquids were measured in the temperature range from (293.15 to 353.15)K. The new and the already available data for the various systems of imidazolium bis(trifluoromethylsulfonyl)imides [RR'IM][BTI] with alkanes, alkenes, cyclic hydrocarbons and alcohols were used to fit the required group interaction parameters for the group contribution methods original and mod. UNIFAC(Do). The predicted results were compared with the experimental data and the results using COSMO-RS(Ol)

  14. Silica-gel-confined ionic liquids: a new attempt for the development of supported nanoliquid catalysis.

    Science.gov (United States)

    Shi, Feng; Zhang, Qinghua; Li, Dongmei; Deng, Youquan

    2005-09-05

    A new concept of designing and synthesizing highly dispersed ionic-liquid catalysts was developed through physical confinement or encapsulation of ionic liquids (with or without metal complex) in a silica-gel matrix through a sol-gel process. We studied ionic liquids such as EMImBF4, BuMImBF4, DMImBF4, CMImBF4, BuMImPF6, either with or without [Pd(PPh3)2Cl2] and [Rh(PPh3)3Cl], in a silica-gel matrix (E = ethyl, Bu = butyl M = methyl, D = decyl, C = cetyl and Im = imidazolium). The contents of ionic liquids and loadings of Pd or Rh were 8-53 wt % and 0.1 approximately 0.15 wt %, respectively. Analyses of FT-Raman spectra showed that abnormal Raman spectra of the confined ionic liquids were observed in comparison with the bulk and pure ionic liquids. EMImBF4 and BuMImBF4 ionic liquids could be completely washed out from the silica-gel matrix under vigorous reflux conditions, but ionic liquids with larger molecular size, for example, DMImBF4 or CMImBF4, could be confined into the silica-gel nanopores relatively firmly. These results suggested that the ionic liquids were physically confined or encapsulated into the silica gel. The N2 adsorption measurements indicated that the silica-gel skeleton was mesoporous with 50-110 A pore size after the BuMImBF4 ionic liquid was removed completely. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis showed that the silica-gel matrix was amorphous and non-uniformly mesoporous. Carbonylation of aniline and nitrobenzene for synthesis of diphenyl urea, carbonylation of aniline for synthesis of carbamates, and oxime transformation between cyclohexanone oxime and acetone were used as test reactions for these catalysts. Catalytic activities were remarkably enhanced with much lower amounts of ionic liquids needed with respect to bulk ionic-liquid catalysts or silica-supported ionic-liquid catalysts prepared with simple impregnation, in which the ionic liquid may be deposited as a thin layer on the support. Such

  15. A novel l-amino acid ionic liquid for quick and highly efficient synthesis of oxime derivatives – An environmental benign approach

    Directory of Open Access Journals (Sweden)

    Parasuraman Karthikeyan

    2016-11-01

    Full Text Available A mild, efficient, and eco-friendly procedure for the conversion of aliphatic, alicyclic and aromatic carbonyl compounds into the corresponding oximes, was catalyzed by a novel imidazolium based ionic liquid coupled with amino acid (asparagine (l-AAIL, l-Amino acid functionalized ionic liquid catalytic system. The quantitative conversion of aryl and alkyl carbonyl compounds into the corresponding oximes was achieved by simply grinding at ambient temperature using 0.05 mmol of catalyst in 50 s. In addition, this L-AAIL catalyst exhibited good reusability for five consecutive trials without significant loss of its catalytic activity.

  16. Synthesis and Applications of Ionic Liquids Derived from Natural Sugars

    Science.gov (United States)

    Chiappe, Cinzia; Marra, Alberto; Mele, Andrea

    Aiming to develop environmentally compatible chemical syntheses, the replacement of traditional organic solvents with ionic liquids (ILs) has attracted considerable attention. ILs are special molten salts with melting points below 100°C that are typically constituted of organic cations (imidazolium, pyridinium, sulfonium, phosphonium, etc.) and inorganic anions. Due to their ionic nature, they are endowed with high chemical and thermal stability, good solvent properties, and non-measurable vapor pressure. Although the recovery of unaltered ILs and recycling partly compensate their rather high cost, it is important to develop new synthetic approaches to less expensive and environmentally sustainable ILs based on renewable raw materials. In fact, most of these alternative solvents are still prepared starting from fossil feedstocks. Until now, only a limited number of ILs have been prepared from renewable sources. Surprisingly, the most available and inexpensive raw material, i.e., carbohydrates, has been hardly exploited in the synthesis of ILs. In 2003 imidazolium-based ILs were prepared from d-fructose and used as solvents in Mizoroki-Heck and Diels-Alder reactions. Later on, the first chiral ILs derived from sugars were prepared from methyl d-glucopyranoside. In the same year, a family of new chiral ILs, obtained from commercial isosorbide (dianhydro-d-glucitol), was described. A closely related approach was followed by other researchers to synthesize mono- and bis-ammonium ILs from isomannide (dianhydro-d-mannitol). Finally, a few ILs bearing a pentofuranose unit as the chiral moiety were prepared using sugar phosphates as glycosyl donors and 1-methylimidazole as the acceptor.

  17. 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.

  18. 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.

  19. Noncovalent interactions in halogenated ionic liquids: theoretical study and crystallographic implications.

    Science.gov (United States)

    Li, Haiying; Lu, Yunxiang; Wu, Weihong; Liu, Yingtao; Peng, Changjun; Liu, Honglai; Zhu, Weiliang

    2013-03-28

    In recent years, several specific imidazolium-based ionic liquids with halogen substituents on the imidazole ring as well as on the alkyl chains have been reported. In this work, noncovalent interactions in four halogenated ionic liquids, i.e. 2-bromo-/iodo- and 4,5-dibromo-/diiodo-1,3-dimethylimidazolium trifluoromethanesulfonates, were systematically investigated using density functional theory calculations. The structural and energetic properties of the ion pairs for such ionic liquids have been fully examined and compared with the non-halogenated ones. It was found that C-X···O halogen bonds, C-H···O hydrogen bonds, and electrostatic interactions with the anion located over the imidazole ring in the ion pairs. In addition, the structures and energetics of two ion pairs for such ionic liquids were also explored to reproduce experimental observations. The halogen-bonded ring structures and the conformers with the concurrent C-H···O and C-X···O contacts were predicted, consistent with the X-ray crystal structures of corresponding organic salts. Finally, the implications of the observed structural and energetic features of ion pairs on the design of halogen-bonding ionic liquids were discussed. The results presented herein should provide useful information in the development of novel halogenated ionic liquids used for specific tasks ranging from organic synthesis to gas absorption.

  20. Highly efficient solid-state dye-sensitized solar cells based on hexylimidazolium iodide ionic polymer electrolyte prepared by in situ low-temperature polymerization

    Science.gov (United States)

    Wang, Guiqiang; Yan, Chao; Zhang, Juan; Hou, Shuo; Zhang, Wei

    2017-03-01

    Solid-state dye-sensitized solar cells (DSCs) are fabricated using a novel ionic polymer electrolyte containing hexylimidazolium iodide (HII) ionic polymer prepared by in situ polymerization of N,N‧-bis(imidazolyl) hexane and 1,6-diiodohexane without an initiator at low temperature (40 °C). The as-prepared HII ionic polymer has a similar structure to alkylimidazolium iodide ionic liquid, and the imidazolium cations are contained in the polymer main chain; so, it can act simultaneously as the redox mediator in the electrolyte. By incorporating an appropriate amount of 1,3-dimethylimidazolium iodide (DMII) in HII ionic polymer (DMII/HII ionic polymer = 0.7:1, weight ratio), the conductivity of the ionic polymer electrolyte is greatly improved due to the formation of Grotthuss bond exchange. In addition, in situ synthesis of ionic polymer electrolyte guarantees a good pore-filling of the electrolyte in the TiO2 photoanode. As a result, the solid-state DSC based on the ionic polymer electrolyte containing HII ionic polymer and DMII without iodine achieves a conversion efficiency of 6.55% under the illumination of 100 mW cm-2 (AM 1.5), which also exhibits a good at-rest stability at room temperature.

  1. Thermal refraction in ionic liquids induced by a train of femtosecond laser pulses

    Science.gov (United States)

    Nóvoa-López, J. A.; López Lago, E.; Domínguez-Pérez, M.; Troncoso, J.; Varela, L. M.; de la Fuente, R.; Cabeza, O.; Michinel, H.; Rodríguez, J. R.

    2014-09-01

    The Z-scan technique is used to characterize the nonlinear refraction induced by a train of ultrashort laser pulses (80 fs, repetition rate 80.75 MHz) for a set of ionic liquids as a function of their structural parameters such as cation, anion type and alkyl chain length in the cation. The nonlinear refractive index change is originated by linear absorption processes which cause a nonlocal and inhomogeneous increase of temperature in the irradiated region of the sample that behaves as a thermal lens. The thermal refraction, according to the thermal lens model, is mainly related to three physical properties of the medium, which are the absorption at the excitation wavelength, the thermal conductivity and the thermo-optic coefficient. We explore the influence of anions and cations on these properties and on the thermal lens strength. The cationic influence was the object of study for the ILs based on the 1-butyl-3-methyl-imidazolium cation. The anionic influence was studied for the ILs based on the bis(trifluoromethylsulfonyl)imide anion. The obtained results show that both cation and anion affect significantly the thermal lens strength. The thermal refraction is 1.6 times higher in 1-butyl-3-methyl-imidazolium chloride than in 1-butyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide, and 3.3 times higher in trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide than in 1-butylpyridinium bis(trifluoromethylsulfonyl)imide. Optical absorption at 810 nm is influenced by both ionic parts, whereas the anion hardly determines the magnitude of the thermal conductivity.

  2. 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

  3. Multitask Imidazolium Salt Additives for Innovative Poly(l-lactide) Biomaterials: Morphology Control, Candida spp. Biofilm Inhibition, Human Mesenchymal Stem Cell Biocompatibility, and Skin Tolerance.

    Science.gov (United States)

    Schrekker, Clarissa M L; Sokolovicz, Yuri C A; Raucci, Maria G; Selukar, Balaji S; Klitzke, Joice S; Lopes, William; Leal, Claudio A M; de Souza, Igor O P; Galland, Griselda B; Dos Santos, João Henrique Z; Mauler, Raquel S; Kol, Moshe; Dagorne, Samuel; Ambrosio, Luigi; Teixeira, Mário L; Morais, Jonder; Landers, Richard; Fuentefria, Alexandre M; Schrekker, Henri S

    2016-08-24

    Candida species have great ability to colonize and form biofilms on medical devices, causing infections in human hosts. In this study, poly(l-lactide) films with different imidazolium salt (1-n-hexadecyl-3-methylimidazolium chloride (C16MImCl) and 1-n-hexadecyl-3-methylimidazolium methanesulfonate (C16MImMeS)) contents were prepared, using the solvent casting process. Poly(l-lactide)-imidazolium salt films were obtained with different surface morphologies (spherical and directional), and the presence of the imidazolium salt in the surface was confirmed. These films with different concentrations of the imidazolium salts C16MImCl and C16MImMeS presented antibiofilm activity against isolates of Candida tropicalis, Candida parapsilosis, and Candida albicans. The minor antibiofilm concentration assay enabled one to determine that an increasing imidazolium salt content promoted, in general, an increase in the inhibition percentage of biofilm formation. Scanning electron microscopy micrographs confirmed the effective prevention of biofilm formation on the imidazolium salt containing biomaterials. Lower concentrations of the imidazolium salts showed no cytotoxicity, and the poly(l-lactide)-imidazolium salt films presented good cell adhesion and proliferation percentages with human mesenchymal stem cells. Furthermore, no acute microscopic lesions were identified in the histopathological evaluation after contact between the films and pig ear skin. In combination with the good morphological, physicochemical, and mechanical properties, these poly(l-lactide)-based materials with imidazolium salt additives can be considered as promising biomaterials for use in the manufacturing of medical devices.

  4. Synthesis of novel ionic liquids and evaluation of their leaching performance in the recovery of copper and zinc from industrial brass slag

    Energy Technology Data Exchange (ETDEWEB)

    Sahina, A.K.; Atalaya, T.S.; Atbakarb, M.; Ocalb, N.; Saridede, M.N.

    2016-07-01

    Imidazolium-based ionic liquids, 1,3-dibenzylimidazolium trifluoroacetate, 1-benzyl-3-ethylimidazolium trifluoroacetate and 1-benzyl-3-propylimidazolium trifluoroacetate were prepared by simple methods, when compared with those in literature sources, and characterized by IR, NMR and GC-MS and LC-MS. These ILs (Ionic Liquids) were employed as leaching agents in the treatment of industrial copper and zinc bearing slag for the recovery of metals. Results showed that synthesized all novel ionic liquids meet the standard specifications of an ionic liquid. Metal recovery rates decrease with time except for zinc dissolution in 1,3-dibenzylimidazolium trifluoroacetate. 1,3-dibenzylimidazolium trifluoroacetate, when compared with others, is a more effective leaching agent for the treatment of copper and zinc bearing brass slag. Metal recovery rates achieved with this IL are 62.58% for zinc and 24.95% for copper. (Author)

  5. 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...

  6. Tunable amphiphilicity and multifunctional applications of ionic-liquid-modified carbon quantum dots.

    Science.gov (United States)

    Wang, Baogang; Song, Aixin; Feng, Lei; Ruan, Hong; Li, Hongguang; Dong, Shuli; Hao, Jingcheng

    2015-04-01

    During the past decade, increasing attention has been paid to photoluminescent nanocarbon materials, namely, carbon quantum dots (CQDs). It is gradually accepted that surface engineering plays a key role in regulating the properties and hence the applications of the CQDs. In this paper, we prepared highly charged CQDs through a one-pot pyrolysis with citric acid as carbon source and a room-temperature imidazolium-based ionic liquid as capping agent. The as-prepared CQDs exhibit high quantum yields up to 25.1% and are stable under various environments. In addition, the amphiphilicity of the CQDs can be facilely tuned by anion exchange, which leads to a spontaneous phase transfer between water and oil phase. The promising applications of the CQDs as ion sensors and fluorescent inks have been demonstrated. In both cases, these ionic-liquid-modified CQDs were found to possess novel characteristics and/or superior functions compared to existing ones.

  7. Influence of ionic liquid on pseudocapacitance performance of electrochemically synthesized conductive polymer: Electrochemical and theoretical investigation.

    Science.gov (United States)

    Ehsani, A; Kowsari, E; Dashti Najafi, M; Safari, R; Mohammad Shiri, H

    2017-08-15

    This study demonstrates a method for improving supercapacitive performance of electrochemically synthesized conductive polymer. In this regards, 1-Butyl-3-methyl imidazolium hexafluorophosphate (BI) as a new high efficient ionic liquid was synthesized using chemical approach and then fabricated POAP/BI films by electro-polymerization of POAP in the presence of BI to serve as the active electrode for electrochemical supercapacitor. Theoretical study (AIM) and electrochemical analysis have been used for characterization of ionic liquid and POAP/BI composite film. Different electrochemical methods including galvanostatic charge-discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy are carried out in order to investigate the performance of the system. This work introduces new most efficient materials for electrochemical redox capacitors with advantages including ease synthesis, high active surface area and stability in an aqueous electrolyte. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Influence of ionic liquids on the dielectric relaxation behavior of CNT based elastomer nanocomposites

    Directory of Open Access Journals (Sweden)

    A. Das

    2012-11-01

    Full Text Available The influence of an imidazolium type ionic liquid (IL on the relaxation behavior of carbon-nanotube (CNT based polychloroprene nanocomposites prepared by melt mixing has been investigated by broadband dielectric spectroscopy. It is demonstrated that the presence of the ionic liquid modifies the relaxation behavior of the pure rubber matrix and leads to a significant increase of the conductivity for the CNT/rubber composites. For the unfilled rubber, a distinct glass transition of the IL is observed for high concentrations demonstrating that the IL forms a separate phase. The increased conductivity of the CNT-filled rubber composites is related to a physical coupling between CNTs and rubber matrix mediated by IL leading to a better dispersion of the CNTs.

  9. Influence of reactive oxygen species on the enzyme stability and activity in the presence of ionic liquids.

    Directory of Open Access Journals (Sweden)

    Pankaj Attri

    Full Text Available In this paper, we have examined the effect of ammonium and imidazolium based ionic liquids (ILs on the stability and activity of proteolytic enzyme α-chymotrypsin (CT in the presence of cold atmospheric pressure plasma jet (APPJ. The present work aims to illustrate the state of art implementing the combined action of ILs and APPJ on the enzyme stability and activity. Our circular dichroism (CD, fluorescence and enzyme activity results of CT have revealed that buffer and all studied ILs {triethylammonium hydrogen sulphate (TEAS from ammonium family and 1-butyl-3-methyl imidazolium chloride ([Bmim][Cl], 1-methylimidazolium chloride ([Mim][Cl] from imidazolium family} are notable to act as protective agents against the deleterious action of the APPJ, except triethylammonium dihydrogen phosphate (TEAP ammonium IL. However, TEAP attenuates strongly the deleterious action of reactive oxygen species (ROS created by APPJ on native structure of CT. Further, TEAP is able to retain the enzymatic activity after APPJ exposure which is absent in all the other systems.This study provides the first combined effect of APPJ and ILs on biomolecules that may generate many theoretical and experimental opportunities. Through this methodology, we can utilise both enzyme and plasma simultaneously without affecting the enzyme structure and activity on the material surface; which can prove to be applicable in various fields.

  10. Nucleophilic Hydroxylation in Water Media Promoted by a Hexa-Ethylene Glycol-Bridged Dicationic Ionic Liquid.

    Science.gov (United States)

    Jadhav, Vinod H; Kim, Jin Gwan; Jeong, Hyeon Jin; Kim, Dong Wook

    2015-07-17

    Hexaethylene glycol bis(3-hexaethylene glycol imidazolium) dimesylate ionic liquid (hexaEG-DHIM) was designed and prepared as a highly efficient promoter for the nucleophilic hydroxylation of alkyl halides to the corresponding alcohol products in neat water media. It was observed that hexaEG-DHIM promoter enhanced the nucleophilicity of water significantly in the reaction. In addition, the hexaEG-DHIM could be reused several times without loss of activity. Moreover, the hydroxylation reactions of base-sensitive and/or polar alkyl halide substrates proceeded highly chemoselectively in excellent yields.

  11. 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.

  12. Synthesis and physical properties of new surfactants based on ionic liquids: Improvement of thermal stability and mechanical behaviour of high density polyethylene nanocomposites.

    Science.gov (United States)

    Livi, Sébastien; Duchet-Rumeau, Jannick; Pham, Thi Nhàn; Gérard, Jean-François

    2011-02-15

    Ionic liquids based on alkyltriphenyl phosphonium and dialkyl imidazolium cations with long alkyl chains have been synthesized and used as new surfactants for cationic exchange of layered silicates. The influence of the alkyl chain length and the chemical nature of the conteranion or of the cation on the thermal stability of these new intercalating agents and on imidazolium- (MMT-I) or phosphonium- (MMT-P) modified montmorillonites have been analyzed by thermogravimetric analysis (TGA). Thermoplastic nanocomposites based on these modified montmorillonites with a very low amount of nanofillers (1wt.%) have been processed by melt mixing using a twin screw extruder. The distribution of the clay layers in a high density polyethylene (HDPE) matrix was characterized and finally the mechanical and thermal properties of the corresponding nanocomposites were determined. Copyright © 2010 Elsevier Inc. All rights reserved.

  13. Charge-tagged N-heterocyclic carbenes (NHC): Direct transfer from ionic liquid solutions and long-lived nature in the gas phase

    Science.gov (United States)

    Rodrigues, Thyago S.; Lesage, Denis; da Silva, Wender A.; Cole, Richard B.; Ebeling, Günter; Dupont, Jaïrton; de Oliveira, Heibbe C. B.; Eberlin, Marcos N.; Neto, Brenno A. D.

    2017-06-01

    Negatively charge-tagged N-heterocyclic carbenes have been formed in solution via deprotonation of imidazolium ions bearing acid side groups and transferred to the gas phase via ESI(-)-MS. The structure of the putative and apparently stable gaseous carbenes formed in such conditions were then probed via reactions with carbon dioxide using a triple quadrupole mass spectrometer particularly optimized for ion/molecule reactions of ESI-generated ions. Complete conversion to imidazolium carboxylates was achieved, which seems to demonstrate the efficiency of the transfer, the gas-phase stability, and the long-lived nature of these unprecedented charge-tagged carbenes and their predominance in the ionic population. Comprehensive studies on the intrinsic reactivity of N-heterocyclic carbenes with silent charge tags are therefore possible. [Figure not available: see fulltext.

  14. Influence of the Ionic Liquid Type on the Gel Polymer Electrolytes Properties

    Science.gov (United States)

    Tafur, Juan P.; Santos, Florencio; Fernández Romero, Antonio J.

    2015-01-01

    Gel Polymer Electrolytes (GPEs) composed by ZnTf2 salt, poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP), and different ionic liquids are synthesized using n-methyl-2-pyrrolidone (NMP) as solvent. Three different imidazolium-based ionic liquids containing diverse cations and anions have been explored. Structural and electrical properties of the GPEs varying the ZnTf2 concentration are analyzed by ATR-FTIR, DSC, TG, and cyclic voltammetry. Free salt IL-GPEs present distinct behavior because they are influenced by the different IL cations and anions composition. However, inclusion of ZnTf2 salt inside the polymers provide GPEs with very similar characteristics, pointing out that ionic transport properties are principally caused by Zn2+ and triflate movement. Whatever the IL used, the presence of NMP solvent inside the polymer’s matrix turns out to be a key factor for improving the Zn2+ transport inside the GPE due to the interaction between Zn2+ cations and carbonyl groups of the NMP. High values of ionic conductivity, low activation energy values, and good voltammetric reversibility obtained regardless of the ionic liquid used enable these GPEs to be applied in Zn batteries. Capacities of 110–120 mAh·g−1 have been obtained for Zn/IL-GPE/MnO2 batteries discharged at −1 mA·cm−2. PMID:26610580

  15. 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.

  16. Ionic Liquids as Novel Lubricants and Additives for Diesel Engine Applications

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jun [ORNL; Blau, Peter Julian [ORNL; Dai, Sheng [ORNL; Luo, Huimin [ORNL; Meyer III, Harry M [ORNL

    2009-01-01

    The lubricating properties of two ionic liquids with the same anion but different cations, one ammonium IL [C8H17]3NH.Tf2N and one imidazolium IL C10mim.Tf2N, were evaluated both in neat form and as oil additives. Experiments were conducted using a standardized reciprocating sliding test using a segment of a Cr-plated diesel engine piston ring against a grey cast iron flat specimen with simulated honing marks as on the engine cylinder liner. The selected ionic liquids were benchmarked against conventional hydrocarbon oils. Substantial friction and wear reductions, up to 55% and 34%, respectively, were achieved for the neat ionic liquids compared to a fully-formulated 15W40 engine oil. Adding 5 vol% ILs into mineral oil has demonstrated significant improvement in the lubricity. One blend even outperformed the 15W40 engine oil with 9% lower friction and 34% less wear. Lubrication regime modeling, worn surface morphology examination, and surface chemical analysis were conducted to help understand the lubricating mechanisms for ionic liquids. Results suggest great potential for using ionic liquids as base lubricants or lubricant additives for diesel engine applications.

  17. Influence of the Ionic Liquid Type on the Gel Polymer Electrolytes Properties

    Directory of Open Access Journals (Sweden)

    Juan P. Tafur

    2015-11-01

    Full Text Available Gel Polymer Electrolytes (GPEs composed by ZnTf2 salt, poly(vinylidene fluoride-co-hexafluoropropylene (PVdF-HFP, and different ionic liquids are synthesized using n-methyl-2-pyrrolidone (NMP as solvent. Three different imidazolium-based ionic liquids containing diverse cations and anions have been explored. Structural and electrical properties of the GPEs varying the ZnTf2 concentration are analyzed by ATR-FTIR, DSC, TG, and cyclic voltammetry. Free salt IL-GPEs present distinct behavior because they are influenced by the different IL cations and anions composition. However, inclusion of ZnTf2 salt inside the polymers provide GPEs with very similar characteristics, pointing out that ionic transport properties are principally caused by Zn2+ and triflate movement. Whatever the IL used, the presence of NMP solvent inside the polymer’s matrix turns out to be a key factor for improving the Zn2+ transport inside the GPE due to the interaction between Zn2+ cations and carbonyl groups of the NMP. High values of ionic conductivity, low activation energy values, and good voltammetric reversibility obtained regardless of the ionic liquid used enable these GPEs to be applied in Zn batteries. Capacities of 110–120 mAh·g−1 have been obtained for Zn/IL-GPE/MnO2 batteries discharged at −1 mA·cm−2.

  18. [Effect of new quaternary imino compounds against selected bacterial and fungal strains. 11. Synthesis of 1-methyl- and 1-ethyl-3-(n-alkoxymethyl)imidazolium chlorides].

    Science.gov (United States)

    Pernak, J; Krysiński, J; Skrzypczak, A

    1985-08-01

    Syntheses and antibacterial activity of the imidazolium compounds are described. Syntheses of the imidazolium chlorides were performed by reaction of 1-alkylimidazole with chloromethylalkyl ether. Antibacterial properties of obtained compounds was tested on 13 strains of bacteria and fungi. Chlorides with n-dodecaoxymethyl radical indicated the best antibacterial activity.

  19. Ionic Nanofluids in Tribology

    Directory of Open Access Journals (Sweden)

    Noelia Saurín

    2015-11-01

    Full Text Available This overview covers the most recent developments in the field of ionic nanofluid lubricants, defined as dispersions of nanoparticles with ionic liquids through the activation of nanophases. The nanophases range from metal nanoparticles and ceramic inorganic nanoparticles, to different carbon nanophases. The combinations with room-temperature ionic liquids can be in the form of mixtures, dispersions, surface-modified nanophases, or chemically-functionalized nanophases. The new ionic nanofluids can be used as base lubricants, as lubricant additives, or as anti-friction and wear-reducing additives in new nanocomposite materials.

  20. Improving Cellulose Dissolution in Ionic Liquids by Tuning the Size of the Ions: Impact of the Length of the Alkyl Chains in Tetraalkylammonium Carboxylate.

    Science.gov (United States)

    Meng, Xiangqian; Devemy, Julien; Verney, Vincent; Gautier, Arnaud; Husson, Pascale; Andanson, Jean-Michel

    2017-04-22

    Twenty ionic liquids based on tetraalkylammonium cations and carboxylate anions have been synthesized, characterized, and tested for cellulose dissolution. The amount of cellulose dissolved in these ionic liquids depends strongly on the size of the ions: from 0 to 22 wt % cellulose can be dissolved at 90 °C. The best ionic liquids are less viscous and ammonium carboxylate based ionic liquids can dissolve as much as imidazolium-based ones. The viscosity of an ionic liquid can be decreased by the addition of DMSO as a cosolvent. After the addition of cosolvent, similar amounts of cellulose per ions are reached for most ionic liquids. As observed by rheology, ionic liquids with the longest alkyl chains form a gel when a high amount of cellulose is dissolved; this drastically limits their potential. Molecular simulations and IR spectroscopy have also been used with the aim of understanding how molecular interactions differ between efficient and inefficient ionic liquids. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Synthesis and characterization of a helicene-based imidazolium salt and its application in organic molecular electronics.

    Science.gov (United States)

    Storch, Jan; Zadny, Jaroslav; Strasak, Tomas; Kubala, Martin; Sykora, Jan; Dusek, Michal; Cirkva, Vladimir; Matejka, Pavel; Krbal, Milos; Vacek, Jan

    2015-02-02

    Herein we demonstrate the synthesis of a helicene-based imidazolium salt. The salt was prepared by starting from racemic 2-methyl[6]helicene, which undergoes radical bromination to yield 2-(bromomethyl)[6]helicene. Subsequent treatment with 1-butylimidazole leads to the corresponding salt 1-butyl-3-(2-methyl[6]helicenyl)-imidazolium bromide. The prepared salt was subsequently characterized by using NMR spectroscopy and X-ray analysis, various optical spectrometric techniques, and computational chemistry tools. Finally, the imidazolium salt was immobilized onto a SiO2 substrate as a crystalline or amorphous deposit. The deposited layers were used for the development of organic molecular semiconductor devices and the construction of a fully reversible humidity sensor. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Dynamic Mass Transfer of Hemoglobin at the Aqueous/Ionic-Liquid Interface Monitored with Liquid Core Optical Waveguide.

    Science.gov (United States)

    Chen, Xuwei; Yang, Xu; Zeng, Wanying; Wang, Jianhua

    2015-08-04

    Protein transfer from aqueous medium into ionic liquid is an important approach for the isolation of proteins of interest from complex biological samples. We hereby report a solid-cladding/liquid-core/liquid-cladding sandwich optical waveguide system for the purpose of monitoring the dynamic mass-transfer behaviors of hemoglobin (Hb) at the aqueous/ionic liquid interface. The optical waveguide system is fabricated by using a hydrophobic IL (1,3-dibutylimidazolium hexafluorophosphate, BBimPF6) as the core, and protein solution as one of the cladding layer. UV-vis spectra are recorded with a CCD spectrophotometer via optical fibers. The recorded spectra suggest that the mass transfer of Hb molecules between the aqueous and ionic liquid media involve accumulation of Hb on the aqueous/IL interface followed by dynamic extraction/transfer of Hb into the ionic liquid phase. A part of Hb molecules remain at the interface even after the accomplishment of the extraction/transfer process. Further investigations indicate that the mass transfer of Hb from aqueous medium into the ionic liquid phase is mainly driven by the coordination interaction between heme group of Hb and the cationic moiety of ionic liquid, for example, imidazolium cation in this particular case. In addition, hydrophobic interactions also contribute to the transfer of Hb.

  3. Neighbor-directed Histidine N(τ)–Alkylation: A Route to Imidazolium-containing Phosphopeptide Macrocycles

    Science.gov (United States)

    Qian, Wen-Jian; Park, Jung-Eun; Grant, Robert; Lai, Christopher C.; Kelley, James A.; Yaffe, Michael B.; Lee, Kyung S.; Burke, Terrence R.

    2016-01-01

    Our recently discovered, selective, on-resin route to N(τ)-alkylated imidazolium-containing histidine residues affords new strategies for peptide mimetic design. In our current work, we demonstrate the use of this chemistry to prepare a series of macrocyclic phosphopeptides, in which imidazolium groups serve as ring-forming junctions. Interestingly, these cationic moieties subsequently serve to charge-mask the phosphoamino acid group that directed their formation. Neighbor-directed histidine N(τ)-alkylation opens the door to new families of phosphopeptidomimetics for use in a range of chemical biology contexts. PMID:26152807

  4. Water-clustering in hygroscopic ionic liquids-an implicit solvent analysis.

    Science.gov (United States)

    Maiti, Amitesh; Kumar, Arvind; Rogers, Robin D

    2012-04-21

    Most ionic liquids are known to be hygroscopic to varying degrees, and that can be detrimental or useful depending upon the application in question. Water can accumulate slowly over hours or days to saturation levels corresponding to the humidity level. When designing or deploying a new ionic liquid it is important to be able to estimate its maximum moisture absorbing ability at the temperature and pressure of its operation. With this goal in mind we have carried out computational studies on three ionic liquid systems based on [BF(4)](-), [PF(6)](-), and [Tf(2)N](-) anions and 1-alkyl-3-methyl-imidazolium ([C(n)mim](+)) cations within an implicit solvent formalism. For highly hygroscopic systems like [C(n)mim][BF(4)] we find that non-iterative calculations with single water molecules can lead to significant underestimation of the maximum moisture content, while iterative calculations can result in miscibility behavior qualitatively different from experimental observations. On the other hand, the inclusion of small hydrogen-bonded water-clusters up to an appropriately chosen size is shown to yield better quantitative agreements with experimentally observed water uptake. Additionally, such calculations appear consistent with a number of thermodynamically interesting phase behaviors, including limited-solubility to full-miscibility transitions as a function of temperature and as a function of the alkyl chain length of the imidazolium cation. For hydrophobic systems like [C(n)mim][PF(6)] and [C(n)mim][Tf(2)N] the computed solubility (for each n) is found to have a smooth convergence behavior as a function of the largest cluster-size considered with the results for the larger clusters being close to that obtained by iterative calculations with single water molecules. This journal is © the Owner Societies 2012

  5. 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.

  6. Efficient biomass pretreatment using ionic liquids derived from lignin and hemicellulose.

    Science.gov (United States)

    Socha, Aaron M; Parthasarathi, Ramakrishnan; Shi, Jian; Pattathil, Sivakumar; Whyte, Dorian; Bergeron, Maxime; George, Anthe; Tran, Kim; Stavila, Vitalie; Venkatachalam, Sivasankari; Hahn, Michael G; Simmons, Blake A; Singh, Seema

    2014-09-02

    Ionic liquids (ILs), solvents composed entirely of paired ions, have been used in a variety of process chemistry and renewable energy applications. Imidazolium-based ILs effectively dissolve biomass and represent a remarkable platform for biomass pretreatment. Although efficient, imidazolium cations are expensive and thus limited in their large-scale industrial deployment. To replace imidazolium-based ILs with those derived from renewable sources, we synthesized a series of tertiary amine-based ILs from aromatic aldehydes derived from lignin and hemicellulose, the major by-products of lignocellulosic biofuel production. Compositional analysis of switchgrass pretreated with ILs derived from vanillin, p-anisaldehyde, and furfural confirmed their efficacy. Enzymatic hydrolysis of pretreated switchgrass allowed for direct comparison of sugar yields and lignin removal between biomass-derived ILs and 1-ethyl-3-methylimidazolium acetate. Although the rate of cellulose hydrolysis for switchgrass pretreated with biomass-derived ILs was slightly slower than that of 1-ethyl-3-methylimidazolium acetate, 90-95% glucose and 70-75% xylose yields were obtained for these samples after 72-h incubation. Molecular modeling was used to compare IL solvent parameters with experimentally obtained compositional analysis data. Effective pretreatment of lignocellulose was further investigated by powder X-ray diffraction and glycome profiling of switchgrass cell walls. These studies showed different cellulose structural changes and differences in hemicellulose epitopes between switchgrass pretreatments with the aforementioned ILs. Our concept of deriving ILs from lignocellulosic biomass shows significant potential for the realization of a "closed-loop" process for future lignocellulosic biorefineries and has far-reaching economic impacts for other IL-based process technology currently using ILs synthesized from petroleum sources.

  7. Use of Ionic liquids as additives in ion exchange chromatography for the analysis of cations.

    Science.gov (United States)

    Di, Huawei; Zhu, Xiashi

    2017-11-01

    The behavior of acids (citric acid, nitric acid, oxalic acid, tartaric acid) as a mobile phase and imidazolium ionic liquids (the bromides, tetrafluoroborates and hexafluorophosphates of 1-ethyl, 1-butyl, and 1-hexyl-3-methylimidazolium) as additives in ion exchange chromatography for cations (Na+ , K+ , Mg2+ , Ca2+ ) separation were studied. The results showed that nitric acid and 1-hexyl-3-methyl-imidazolium hexafluorophosphate offered the most interesting features in the separation of cations, such as lower retention time and better resolution. The selected optimal conditions were achieved by adding 0.10 mM 1-hexyl-3-methyl-imidazolium hexafluorophosphate in 4.0 mM HNO3 mobile phase for the separation of four cations with the flow rate of 0.9 mL/min at room temperature (25°C). The linear regression equations of Na+ , K+ , Mg2+ , Ca2+ were S = 4.4763c + 0.0209, S = 3.8903c - 0.0087, S = 6.3974c - 0.0173, and S = 7.601c - 0.0339 and the limits of detection of Na+ , K+ , Mg2+ , Ca2+ were 0.296, 4.98, 0.0970, and 1.22 μg/L, respectively. In this work, four cations in samples were successfully detected. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Separation of benzene and hexane by solvent extraction with 1-alkyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}amide ionic liquids: effect of the alkyl-substituent length.

    Science.gov (United States)

    Arce, Alberto; Earle, Martyn J; Rodríguez, Héctor; Seddon, Kenneth R

    2007-05-10

    The influence of the alkyl-substituent chain in 1-alkyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}amide ionic liquids ([C(n)mim][NTf(2)], where n is the length of a linear alkyl chain) as solvents for the separation of benzene and hexane by liquid extraction was investigated. The liquid-liquid equilibrium (LLE) at 25 degrees C for the ternary systems ([C(n)mim][NTf(2)] + hexane + benzene), with n taking the values 4, 8, 10, and 12, were determined. These data were analyzed and compared to those previously reported for the system ([C(2)mim][NTf(2)] + hexane + benzene). The results show that short alkyl chains on the imidazolium cation of the ionic liquid lead to a better extractive separation of benzene and hexane, and reveal the influence of the relative degree of ordering in the ionic liquids on the extraction parameters.

  9. Dynamic electrowetting and dewetting of ionic liquids at a hydrophobic solid-liquid interface.

    Science.gov (United States)

    Li, Hua; Paneru, Mani; Sedev, Rossen; Ralston, John

    2013-02-26

    The dynamic electrowetting and dewetting of ionic liquids are investigated with high-speed video microscopy. Five imidazolium-based ionic liquids ([BMIM]BF(4), [BMIM]PF(6), [BMIM]NTf(2), [HMIM]NTf(2), and [OMIM]BF(4)) are used as probe liquids. Droplets of ionic liquids are first spread on an insulated electrode by applying an external voltage (electrowetting) and then allowed to retract (dewetting) when the voltage is switched off. The base area of the droplet varies exponentially during both the electrowetting and retraction processes. The characteristic time increases with the viscosity of the ionic liquid. The electrowetting and retraction kinetics (dynamic contact angle vs contact line speed) can be described by the hydrodynamic or the molecular-kinetic model. Energy dissipation occurs by viscous and molecular routes with a larger proportion of energy dissipated at the three-phase contact line when the liquid meniscus retracts from the solid surface. The outcomes from this research have implications for the design and control of electro-optical imaging systems, microfluidics, and fuel cells.

  10. Ionic Liquids As Self-Assembly Guide for the Formation of Nanostructured Block Copolymer Membranes

    KAUST Repository

    Madhavan, Poornima

    2015-04-30

    Nanostructured block copolymer membranes were manufactured by water induced phase inversion, using ionic liquids (ILs) as cosolvents. The effect of ionic liquids on the morphology was investigated, by using polystyrene-b-poly(4-vinyl pyridine) (PS-b-PV4P) diblock as membrane copolymer matrix and imidazolium and pyridinium based ILs. The effect of IL concentration and chemical composition was evident with particular interaction with P4VP blocks. The order of block copolymer/ILs solutions previous to the membrane casting was confirmed by cryo scanning electron microscopy and the morphologies of the manufactured nanostructured membranes were characterized by transmission and scanning electron microscopy. Non-protic ionic liquids facilitate the formation of hexagonal nanoporous block copolymer structure, while protic ILs led to a lamella-structured membrane. The rheology of the IL/block copolymer solutions was investigated, evaluating the storage and loss moduli. Most membranes prepared with ionic liquid had higher water flux than pure block copolymer membranes without additives.

  11. Assessing chemical toxicity of ionic liquids on Vibrio fischeri: Correlation with structure and composition.

    Science.gov (United States)

    Montalbán, Mercedes G; Hidalgo, Juana M; Collado-González, Mar; Díaz Baños, F Guillermo; Víllora, Gloria

    2016-07-01

    One of the most important properties of ionic liquids is their non-volatility, making them potentially "green" alternatives to volatile organic compounds. However, they are widely soluble in water, meaning that they can be released into aquatic ecosystems and so contribute to water pollution. Nevertheless, although the toxicity of ILs has been widely assessed in the literature, the information is still scarce due to the great number of ionic liquids that have been synthesized. The present work reports the toxicity of twenty-nine imidazolium-, pyridinium- and ammonium-based ionic liquids towards the bioluminescent photobacterium Vibrio fischeri. When the effect of the type of anion, the length of the alkyl chain of the cation, the cation core and the presence of a functionalized side chain in the cation on ionic liquid toxicity were analyzed, the main influence was seen to be exercised by the alkyl chain length. A Quantitative Structure-Activity Relationships-based method was used to compare the experimental results with previously estimated values and very good agreement was obtained. A relationship between the toxicity, expressed as Log EC50, and the 1-octanol-water partition coefficient was established. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Ionic conduction o phosphonium-based ionic liquids and their application in nanocrystalline solar cells; Conduccion ionica en liquidos ionicosbasados en fsfonios y sus aplicacion em celdas solares nanocristalinas

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, Rosa E.; Torres-Gonzalez, Luis; Sanchez, Eduardo M. [Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza NL (Mexico). Facultad de Ciencias Quimicas. Lab. de Investigacion del Vidrio], e-mail: info_labiv@yahoo.com

    2006-07-01

    Ionic liquids are molten salts formed by organic cations as imidazolium, ammonium, pyridinium, picolinium and phosphonium in combination with several inorganic and organic anions. A new systematic series of phosphonium iodides (PI's) with low melting points have been prepared and properly characterized. Ionic conductivity was determined by impedance spectroscopy on molten salts as well as electrolytic solutions prepared by a mixture of PI's with low vapor pressure solvents. The conductivity dependence vs solvent concentration was interpreted in terms of the Fuoss-Krauss ion association theory. The conductivity did increased dramatically when small quantities of iodine were added, this phenomenon is explained in terms of the Grotthus charge transfer mechanism. Finally, several nanocrystalline solar cells were assembled with electrolytic solutions performing an efficiency up to 5.9% under an illuminance of 27 000 lux. (author)

  13. Green Brönsted acid ionic liquids as novel corrosion inhibitors for carbon steel in acidic medium.

    Science.gov (United States)

    Cao, Shuyun; Liu, Dan; Zhang, Peng; Yang, Lixia; Yang, Peng; Lu, Hui; Gui, Jianzhou

    2017-08-18

    New ionic liquids with multiple Brönsted acid sites were synthesized in ≥98% yield, and their inhibiting properties for the corrosion of carbon steel in 0.5 M HCl solution had been evaluated using electrochemical impedance spectroscopy, potentiodynamic polarization and weight loss method, finally the possible inhibiting mechanism was proposed according to UV-visible spectroscopic measurements and surface analysis including SEM and XPS techniques. The designed cation structure of Brönsted acid ionic liquids (BAILs), with one phenyl and two imidazolium rings, makes them good mixed-type inhibitors via the adsorption of BAILs on the steel surface to suppress both anodic and cathodic processes, obeying Langmuir adsorption isotherm. As potential acid catalysts, BAILs show nice corrosion inhibiting performance in acidic medium regardless of their Brönsted acidity, which is of great significance to enlarge the industry applications of BAILs.

  14. Gels and lyotropic liquid crystals: using an imidazolium-based catanionic surfactant in binary solvents.

    Science.gov (United States)

    Cheng, Ni; Hu, Qiongzheng; Bi, Yanhui; Xu, Wenwen; Gong, Yanjun; Yu, Li

    2014-08-05

    The self-assembly behavior of an imidazolium-based catanionic surfactant, 1-butyl-3-methylimidazolium dodecylsulfate ([C4mim][C12H25SO4]), was investigated in water-ethylammonium nitrate (EAN) mixed solvents with different volume ratios. It is particular interesting that this simple surfactant could not only form lyotropic liquid crystals (LLC) with multimesophases, i.e., normal hexagonal (H1), lamellar liquid crystal (Lα), and reverse bicontinuous cubic phase (V2), in the water-rich environment but also act as an efficient low-molecular-weight gelator (LMWG) which gelated EAN-abundant binary media in a broad concentration range. The peculiar nanodisk cluster morphology of gels composed of similar bilayer units was first observed. FT-IR spectra and density functional theory (DFT) calculations reveal that strong H bonding and electrostatic interactions between EAN and the headgroups of [C4mim][C12H25SO4] are primarily responsible for gelation. The self-assembled gels displayed excellent mechanical strength and a thermoreversible sol-gel transition. It is for the first time that a rich variety of controllable ordered aggregates could be observed only by simply modulating the concentration of a single imidazolium-based catanionic surfactant or the ratio of mixed solvents. This environmentally friendly system is expected to have broad applications in various fields, such as materials science, drug delivery systems, and supramolecular chemistry.

  15. On the physical origin of the cation-anion intermediate bond in ionic liquids Part I. Placing a (weak) hydrogen bond between two charges.

    Science.gov (United States)

    Lehmann, Sebastian B C; Roatsch, Martin; Schöppke, Matthias; Kirchner, Barbara

    2010-07-21

    The intermediate bond forces in ionic liquids are investigated from static quantum chemical calculations at various methods and two basis sets. The experimentally observed red-shift of the donor-proton bond stretching frequency due to a bond elongation is confirmed by all methods. Comparing Hartree-Fock to second-order Møller-Plesset perturbation theory, the Hartree-Fock method gives in many cases an erroneous description of the geometries. Furthermore, the Hartree-Fock interaction energies can deviate up to 60 kJ mol(-1) from Møller-Plesset perturbation theory indicating the importance of dispersion interaction. While the usual trends of decreasing stability or interaction energies with increasing ion sizes are found, the geometries involving hydrogen atoms do not change this order of total interaction energies. Therefore, the hydrogen bond is not the most important interaction for ion pairs with regard to the total interaction energy. On the other hand, the different established analysis methods give rise to hydrogen bonding in several ion pairs. Charge analysis reveals the hydrogen-bonding character of the ion pair and shows, depending on the type of ions combined and further on the type of conformers considered, that a hydrogen bond can be present. The possibility of hydrogen bonding is also shown by an analysis of the frontier orbitals. Calculating potential energy surfaces and observing from this the change in the donor proton bond indicates that regular hydrogen bonds are possible in ion pairs of ionic liquids. Thereby, the maximum of bond elongation exceeds the one of a usual hydrogen bond by far. The more salt-like hydrogen-bonded ion pair [NH(4)][BF(4)] exhibits a steeper maximum than the more ionic liquid like ion pair [EtNH(3)][BF(4)]. The fact that imidazolium-based ionic liquids as [Emim][Cl] can display two faces, hydrogen bonding and purely ionic bonding, points to a disturbing rather than stabilizing role of hydrogen bonding on the interaction of

  16. 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.

  17. Photophysics of ionic biochromophores

    CERN Document Server

    Brøndsted Nielsen, Steen

    2014-01-01

    This concise guide to studying ionic biochromophores features the first integrated overview of the photophysics of differing classes of biomolecules, from single amino acids to DNA. It includes an appraisal of the latest theories and experimental techniques.

  18. Impact of water dilution and cation tail length on ionic liquid characteristics: Interplay between polar and non-polar interactions

    Science.gov (United States)

    Hegde, Govind A.; Bharadwaj, Vivek S.; Kinsinger, Corey L.; Schutt, Timothy C.; Pisierra, Nichole R.; Maupin, C. Mark

    2016-08-01

    The recalcitrance of lignocellulosic biomass poses a major challenge that hinders the economical utilization of biomass for the production of biofuel, plastics, and chemicals. Ionic liquids have become a promising solvent that addresses many issues in both the pretreatment process and the hydrolysis of the glycosidic bond for the deconstruction of cellulosic materials. However, to make the use of ionic liquids economically viable, either the cost of ionic liquids must be reduced, or a less expensive solvent (e.g., water) may be added to reduce the overall amount of ionic liquid used in addition to reducing the viscosity of the binary liquid mixture. In this work, we employ atomistic molecular dynamics simulations to investigate the impact of water dilution on the overall liquid structure and properties of three imidazolium based ionic liquids. It is found that ionic liquid-water mixtures exhibit characteristics that can be grouped into two distinct regions, which are a function of the ionic liquid concentration. The trends observed in each region are found to correlate with the ordering in the local structure of the ionic liquid that arises from the dynamic interactions between the ion pairs. Simulation results suggest that there is a high level of local ordering in the molecular structure at high concentrations of ionic liquids that is driven by the aggregation of the cationic tails and the anion-water interactions. It is found that as the concentration of ionic liquids in the binary mixture is decreased, there is a point at which the competing self and cross interaction energies between the ionic liquid and water shifts away from a cation-anion dominated regime, which results in a significant change in the mixture properties. This break point, which occurs around 75% w/w ionic liquids, corresponds to the point at which water molecules percolate into the ionic liquid network disrupting the ionic liquids' nanostructure. It is observed that as the cationic alkyl

  19. Fullerol ionic fluids

    KAUST Repository

    Fernandes, Nikhil

    2010-01-01

    We report for the first time an ionic fluid based on hydroxylated fullerenes (fullerols). The ionic fluid was synthesized by neutralizing the fully protonated fullerol with an amine terminated polyethylene/polypropylene oxide oligomer (Jeffamine®). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding significantly perturbs the thermal transitions and melting/crystallization behavior of the amine. In contrast, both the normalized heat of fusion and crystallization of the amine in the control are similar to those of the neat amine consistent with a physical mixture of the fullerols/amine with minimal interactions. In addition to differences in thermal behavior, the fullerol ionic fluid exhibits a complex viscoelastic behavior intermediate between the neat Jeffamine® (liquid-like) and the control (solid-like). © 2010 The Royal Society of Chemistry.

  20. Reusable and Efficient Polystryrene-supported Acidic Ionic Liquid Catalyst for Mononitration of Aromatic Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Li, Li Xia; Ling, Qi Long; Liu, Zu Liang; Xing, Xiao Dong; Zhu, Xiao Qin; Meng, Xiao [Nanjing Univ. of Science and Technology, Nanjing (China)

    2012-10-15

    A series of polystyrene-supported 1-(propyl-3-sulfonate)-3-methyl-imidazolium hydrosulfate acidic ionic liquid (PS-[SO{sub 3}H-PMIM][HSO{sub 4}]) catalysts were prepared and tested for mononitration of simple aromatics compounds with nitric acid. It was found that the reactivity of the catalysts increased with increasing [SO{sub 3}HPMIM][HSO{sub 4}] content. The para-selectivity was not only related to the [SO{sub 3}H-PMIM][HSO{sub 4}] content but also the substituent groups in aromatics. A reaction mechanism of nitration over this new catalyst was proposed. The catalytic activity of this catalyst decreased slightly after fifth runs in the synthesis of nitrotoluene.

  1. 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

  2. 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.

  3. Long-Chain Alkylimidazolium Ionic Liquid Functionalization of Cellulose Nanofibers and Their Embedding in HDPE Matrix

    Directory of Open Access Journals (Sweden)

    Catalin Croitoru

    2016-01-01

    Full Text Available This paper presents a possible alternative to traditional cellulose nanofibers functionalization, by treatment of the material at low temperatures (25–35°C with electron-beam irradiated 1-hexyl-3-methylimidazolium chloride ionic liquid. The treatment promotes decreasing the crystallinity of the cellulose with up to 45% and possible imidazolium moieties grafting to cellulose, as demonstrated from FTIR, XRD, and elemental analysis. The grafting determines water vapors uptake values with 50–70% lower and water vapors uptake rate with 50% lower than those of reference cellulose nanofibers. The grafting determined also improved adhesion of the cellulose nanofibers to HDPE, thus contributing to the obtaining of polymer matrix composites with improved properties.

  4. Mechanism of extractive/oxidative desulfurization using the ionic liquid inimidazole acetate: a computational study.

    Science.gov (United States)

    Wang, Hanlu; Xu, Mingsheng; Zhou, Rujin

    2017-02-01

    The dual role of the ionic liquid 1-butyl-3-methyl-imidazolium trifluoroacetic acid ([C4mim]TFA) as an extractant for thiophene (TH) and a catalyst for the oxidation of TH was explored at the molecular level by performing density functional theory (DFT) calculations. The calculated interaction energies demonstrated why [C4mim]TFA is a better extractant for thiophene sulfone (THO2) than for TH. Two pathways were proposed for the oxidation of TH to THO2 with [C4mim]TFA acting as a catalyst. In the dominant pathway, a peracid is formed which then oxidizes TH to the sulfoxide and sulfones. The presence of [C4mim]TFA was found to greatly reduce the barrier to the oxidative desulfurization (ODS) of TH using H2O2 as an oxidant. Graphical Abstract Possible reaction mechanisms of TH with the aid of [C4mim]TFAᅟ.

  5. Dual guar/ionic liquid gels and biohybrid material thereof: rheological investigation.

    Science.gov (United States)

    Verger, Lucie; Corre, Solenn; Poirot, Robin; Quintard, Guilhem; Fleury, Etienne; Charlot, Aurélia

    2014-02-15

    Polysaccharide-based ion gels were prepared by mixing biosourced guar gums with imidazolium ionic liquid (IL) molecules that act as crosslinking agents. The in-depth investigation of the rheological properties of the guar/IL solutions emphasized that the shear viscoelastic properties can be finely tuned by IL chemical structure, concentration and molecular weight of guar chains as well as by temperature changes. Under suited conditions, highly elastic physical ion gels were formed as a result of multiple guar/IL, guar/guar and IL/IL interactions. Such synergistic associations were usefully exploited to elaborate films dually composed of guar chains and entrapped IL molecules. Their thermomechanical properties, which revealed a solid-state behavior, were closely controlled by the structural parameters of the constituents. This straightforward approach, which requires no chemical derivatization step, provides a facile way to design physical gels with a large applicative potential. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Niobium(v) chloride and imidazolium bromides as efficient dual catalyst systems for the cycloaddition of carbon dioxide and propylene oxide

    KAUST Repository

    Wilhelm, Michael E.

    2014-02-19

    The application of niobium(v) chloride and several imidazolium bromides as catalyst systems for the cycloaddition of propylene oxide (PO) with carbon dioxide to propylene carbonate (PC) is reported. A set of 31 different imidazolium bromides has been synthesized with varying substituents at all five imidazolium ring atoms, of which 17 have not been reported before. The impact of different substitution patterns (steric and electronic changes and solubility in PO) at the imidazolium ring on the catalytic activity was investigated. The optimisation of the catalyst structure allows for the valorisation of carbon dioxide under mild reaction conditions with high reaction rates in very good yield and selectivity for PC. This journal is © the Partner Organisations 2014.

  7. Electrochemical reduction of CO2 to ethylene glycol on imidazolium ion-terminated self-assembly monolayer-modified Au electrodes in an aqueous solution.

    Science.gov (United States)

    Tamura, Jun; Ono, Akihiko; Sugano, Yoshitsune; Huang, Chingchun; Nishizawa, Hideyuki; Mikoshiba, Satoshi

    2015-10-21

    Imidazolium ion-terminated self-assembled monolayer (SAM)-modified electrodes achieve CO2 conversion while suppressing hydrogen evolution. Immobile imidazolium ion on gold (Au) electrodes reduce CO2 at low overpotential. The distance between electrode and imidazolium ion separated by alkane thiol affects CO2 reduction activity. CO2 reduction current depends on the tunnel current rate. Although the product of CO2 reduction at the bare Au electrode is CO, SAM-modified electrodes produce ethylene glycol in aqueous electrolyte solution without CO evolution. The faradaic efficiency reached a maximum of 87%. CO2 reduction at SAM-modified electrodes is unaffected by reduction activity of Au electrode. This phenomenon shows that the reaction field of CO2 reduction is not the electrode surface but the imidazolium ion monolayer.

  8. Phosphoric acid doped imidazolium polysulfone membranes for high temperature proton exchange membrane fuel cells

    DEFF Research Database (Denmark)

    Yang, Jingshuai; Li, Qingfeng; Jensen, Jens Oluf

    2012-01-01

    A novel acid–base polymer membrane is prepared by doping of imidazolium polysulfone with phosphoric acid for high temperature proton exchange membrane fuel cells. Polysulfone is first chloromethylated, followed by functionalization of the chloromethylated polysulfone with alkyl imidazoles i...... group is achieved in 85wt% H3PO4 at room temperature. The membranes exhibit a proton conductivity of 0.015–0.022Scm−1 at 130–150°C under 15mol% water vapor in air, and a tensile strength of 5–6MPa at 130°C under ambient humidity. Fuel cell tests show an open circuit voltage as high as 0.96V and a peak...

  9. Macroscopic and microscopic study of 1-ethyl-3-methyl-imidazolium acetate-water mixtures.

    Science.gov (United States)

    Hall, Craig A; Le, Kim A; Rudaz, Cyrielle; Radhi, Asanah; Lovell, Christopher S; Damion, Robin A; Budtova, Tatiana; Ries, Michael E

    2012-10-25

    Mixtures of 1-ethyl-3-methyl-imidazolium acetate ([C2mim][OAc]) and water across the entire composition range, from pure [C2mim][OAc] to pure water, have been investigated using density, viscosity, and NMR spectroscopy, relaxometry, and diffusion measurements. These results have been compared to ideal mixing laws for the microscopic data obtained from the NMR results and macroscopic data through the viscosity and density. It was also found that the mixing of the two fluids is exothermal. The proton spectra indicate though that [C2mim][OAc] and water are interacting without the formation of new compounds. The maximal deviations of experimental data from theoretical mixing rules were all found to occur within the range 0.74 ± 0.06 mol fraction of water, corresponding to approximately three water molecules per [C2mim][OAc] molecule.

  10. Kinetics and Mechanism of Oxidation of Aromatic Aldehydes by Imidazolium Dichromate in Aqueous Acetic Acid Medium

    Directory of Open Access Journals (Sweden)

    S. Sheik Mansoor

    2009-01-01

    Full Text Available The kinetics of oxidation of benzaldehyde (BA and para-substituted benzaldehydes by imidazolium dichromate (IDC has been studied in aqueous acetic acid medium in the presence of perchloric acid. The reaction is first order each in [IDC], [Substrate] and [H+]. The reaction rates have been determined at different temperatures and the activation parameters calculated. Electron withdrawing substituents are found to increase the reaction and electron releasing substituents are found to retard the rate of the reaction and the rate data obey the Hammett relationship. The products of the oxidation are the corresponding acids. The rate decreases with the increase in the water content of the medium. A suitable mechanism is proposed.

  11. Novel imidazole fluorescent poly(ionic liquid) nanoparticles for selective and sensitive determination of pyrogallol.

    Science.gov (United States)

    Li, Zhouyang; Yang, Yiwen; Zeng, Yanbo; Wang, Jianbo; Liu, Haiqing; Guo, Longhua; Li, Lei

    2017-11-01

    This paper reports novel imidazole fluorescent poly(ionic liquid) nanoparticles (FPILNs) of poly(1-[(4-methyphenyl)methyl]-3-vinyl-imidazolium bromide (poly([MVI]Br) for selective and sensitive determination of pyrogallol. An imidazole ionic liquid of 1-[(4-methyphenyl)methyl]-3-vinyl-imidazolium bromide ([MVI]Br) was synthesized and used as the only monomer to obtain poly([MVI]Br) possessing phenyl fluorophores using a radical polymerization technique. The obtained poly([MVI]Br) can form nanoparticles in water. Scanning electron microscopy and dynamic light scattering results revealed majority of poly([MVI]Br) FPILNs with diameters ranging from 40 to 400nm. Although [MVI]Br showed weak fluorescence intensity, poly([MVI]Br) FPILNs exhibited strong fluorescence intensity with a quantum yield of 0.192, which is attributed to the presence of significant number of phenyl fluorophores and rigid construction. The selective and sensitive determination of pyrogallol was achieved through fluorescence quenching of poly([MVI]Br) FPILNs, and the quenching was attributed to the oxidation of poly([MVI]Br) FPILNs by O2˙¯ produced by pyrogallol autoxidation. The poly([MVI]Br) FPILNs-based sensor demonstrated a good linear relationship between the extent of fluorescence quenching and the concentration of pyrogallol in a range of 0.05 - 10.0μM, achieving a detection limit of 0.01μM. Furthermore, the poly([MVI]Br) FPILNs-based assay detected pyrogallol in environmental water samples, suggesting its potential to be applied for practical purposes. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Ionic liquids as passive monitors of an atmosphere rich in mercury

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, M.A. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, 04510 Mexico D.F. (Mexico); Solis, C., E-mail: corina@fisica.unam.mx [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, 04510 Mexico D.F. (Mexico); Andrade, E. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, 04510 Mexico D.F. (Mexico); Mondragon, M.A. [Centro de Fisica Aplicada y Tecnologia Avanzada, Departamento de Nanotecnologia, Universidad Nacional Autonoma de Mexico, Apartado Postal 1-1010, Queretaro 76000 (Mexico); Isaac-Olive, K. [Facultad de Medicina, Universidad Autonoma del Estado de Mexico, Paseo Tollocan s/n, esq. Jesus Carranza, Toluca, 50120 Estado de Mexico (Mexico); Rocha, M.F. [ESIME Instituto Politecnico Nacional, ALM Zacatenco, 07738 Mexico D.F. (Mexico)

    2011-12-15

    An ionic liquid (IL) is a compound at dynamical equilibrium in which at any time more than 99.99% of it is shifted toward the ionic rather than the molecular species. ILs have raised considerable attention during the past few years due to their extremely low vapor pressure, good electrolytic properties and wide electrochemical window. Also, they remain liquid at a wide range of temperature. ILs are able to dissolve some non polar chemical species as well as some very polar ones. Their main applications have been so far in environmental chemistry and can be considered as environmental friendly solvents. Mercury is a naturally occurring element that is found in the atmosphere, generally present in three forms: elemental (Hg{sup 0}), oxidized, and particulate-bounded. It is a very toxic element and its assessment in the environment is highly desired, however due to its volatility is an element difficult to detect by conventional sampling methods. This paper presents the results of a research on mercury binding using ILs. The following ILs were tested: 1-butyl-3-methyl-imidazolium-hexafluorophosphate [BMIM][PF{sub 6}] and 1-butyl-3-methyl-imidazolium thiocyanate [BMIM] [SCN]. Known amounts of ILs were introduced, in the form of bulk or thin coating layer, to a 70 mL glass tube with a known amount of metallic Hg and sealed with a PTFE Registered-Sign cap. The concentration of Hg in the IL was measured after 12 weeks of exposure. Total Hg determination was performed by particle X-ray emission (PIXE). Changes in the spectroscopic properties due to the Hg binding were followed by Raman and infrared (IR) spectroscopy. The sorption efficiency for the ILs under different experimental conditions is discussed.

  13. Synthesis of Silver Nanoparticles Using Hydroxyl Functionalized Ionic Liquids and Their Antimicrobial Activity

    Directory of Open Access Journals (Sweden)

    Young Key Shim

    2008-05-01

    Full Text Available We report a new one phase method for the synthesis of uniform monodisperse crystalline Ag nanoparticles in aqueous systems that has been developed by using newly synthesized mono and dihydroxylated ionic liquids and cationic surfactants based on 1,3-disubstituted imidazolium cations and halogens anions. The hydroxyl functionalized ionic liquids (HFILs and hydroxyl functionalized cationic surfactants (HFCSs also simultaneously acts both as the reductant and protective agent. By changing the carbon chain length, alcohol structure and anion of the 1,3-imidazolium based HFILs and HFCSs the particle size, uniform and dispersibility of nanoparticles in aqueous solvents could be controlled. Transmission electron microscopy (TEM, electron diffraction, UV-Vis and NMR, were used for characterization of HFILs, HFCSs and silver nanoparticles. TEM studies on the solution showed representative spherical silver nanoparticles with average sizes 2-8 nm, particularly 2.2 nm and 4.5 nm in size range and reasonable narrow particle size distributions (SD-standard distribution 0.2 nm and 0.5 nm respectively. The all metal nanoparticles are single crystals with face centered cubic (fcc structure. The silver nanoparticles surface of plasmon resonance band (λmax around 420 nm broadened and little moved to the long wavelength region that indicating the formation of silver nanoparticles dispersion with broad absorption around infrared (IR region. Silver complexes of these HFILs as well as different silver nanoparticles dispersions have been tested in vitro against several gram positive and gram negative bacteria and fungus. The silver nanoparticles providing environmentally friendly and high antimicrobial activity agents.

  14. Neighbor-Directed Histidine N (s)–Alkylation: A Route to Imidazolium-Containing Phosphopeptide Macrocycles-Biopolymers | Center for Cancer Research

    Science.gov (United States)

    Our recently discovered, selective, on-resin route to N(s)-alkylated imidazolium-containing histidine residues affords new strategies for peptide mimetic design. In this, we demonstrate the use of this chemistry to prepare a series of macrocyclic phosphopeptides, in which imidazolium groups serve as ring-forming junctions. Interestingly, these cationic moieties subsequently serve to charge-mask the phosphoamino acid group that directed their formation.

  15. Vapor pressures of 1,3-dialkylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquids with long alkyl chains

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Marisa A. A., E-mail: lbsantos@fc.up.pt, E-mail: marisa.alexandra.rocha@gmail.com [Centro de Investigação em Química, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal); Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Den Dolech 2, 5612 AZ Eindhoven (Netherlands); Coutinho, João A. P. [CICECO, Departamento de Química, Universidade de Aveiro, P-3810-193 Aveiro (Portugal); Santos, Luís M. N. B. F., E-mail: lbsantos@fc.up.pt, E-mail: marisa.alexandra.rocha@gmail.com [Centro de Investigação em Química, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal)

    2014-10-07

    This work presents the vapor pressure at several temperatures for the 1,3-dialkylimidazolium bis(trifluoromethylsulfonyl)imide series, [C{sub N/2}C{sub N/2}im][NTf{sub 2}] (N = 14, 16, 18, and 20), measured by a Knudsen effusion method combined with a quartz crystal microbalance. The thermodynamic properties of vaporization of the ionic liquids under study are analysed together with the results obtained previously for the shorter alkyl chain length [C{sub N/2}C{sub N/2}im][NTf{sub 2}] (N = 2, 4, 6, 8, 10, and 12), in order to evaluate the effect of the alkyl side chains of the cation and to get additional insights concerning the nanostructuration of ionic liquids. The symmetry effect is explored, based on the comparison with the asymmetric imidazolium based ionic liquids, [C{sub N-1}C{sub 1}im][NTf{sub 2}]. A trend shift on the thermodynamic properties of vaporization along the alkyl side chains of the extended symmetric ionic liquids, around [C{sub 6}C{sub 6}im][NTf{sub 2}], was detected. An intensification of the odd-even effect was observed starting from [C{sub 6}C{sub 6}im][NTf{sub 2}], with higher enthalpies and entropies of vaporization for the odd numbered ionic liquids, [C{sub 7}C{sub 7}im][NTf{sub 2}] and [C{sub 9}C{sub 9}im][NTf{sub 2}]. Similar, but less pronounced, odd-even effect was found for the symmetric ionic liquids with lower alkyl side chains length, [C{sub N/2}C{sub N/2}im][NTf{sub 2}] (with N = 4, 6, 8, 10, and 12). This effect is related with the predominant orientation of the terminal methyl group of the alkyl chain to the imidazolium ring and their influence in the cation-anion interaction. The same Critical Alkyl length at the hexyl, (C{sub 6}C{sub 1}and C{sub 6}C{sub 6}) was found for both asymmetric and symmetric series indicating that the nanostructuration of the ionic liquids is related with alkyl chain length.

  16. High-Performance Ruthenium Sensitizers Containing Imidazolium Counterions for Efficient Dye Sensitization in Water.

    Science.gov (United States)

    Li, Xiaoyu; Li, Shiqing; Gao, Ge; Wu, Di; Lan, Jingbo; Wang, Ruilin; You, Jingsong

    2017-07-21

    A new type of water-soluble ruthenium sensitizers incorporating imidazolium counterions, denoted [DMPI]2 -Ru and [DMHI]2 -Ru, has been developed, which can be efficiently adsorbed onto TiO2 photoanodes in aqueous solution. Owing to the good thermal stability of imidazolium, [DMPI]2 -Ru adsorbed on TiO2 has a higher decomposition temperature than N719 dye [di(tetrabutylammonium) cis-di(thiocyanato)bis(2,2'-bipyridine-4,4'-dicarboxylato)ruthenium(II)]. When using organic solvent-based I- /I3- electrolytes, solars cell based on [DMPI]2 -Ru-sensitized TiO2 in water show high power conversion efficiencies (PCE) of up to 10.2 %, which is higher than that of N719 (9.9 %) under the common conditions for dye sensitization in organic solvent. [DMHI]2 -Ru, with poorer water solubility than [DMPI]2 -Ru, gives a smaller dye-adsorption amount on TiO2 and thus a lower PCE of 9.4 %. From the viewpoint of safety and environmental impact, the fabrication of dye-sensitized solar cells (DSSCs) by using water as solvent is undoubtedly a preferable strategy. Although the [DMPI]2 -Ru-based device fabricated by using water as the solvent for both the dye-sensitization process and the electrolyte gives a relatively low efficiency, it provides a promising approach for the practical application of DSSCs. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Characterization and Applications of Kaolinite Robustly Grafted by an Ionic Liquid with Naphthyl Functionality

    Science.gov (United States)

    Detellier, Christian

    2017-01-01

    Functionalization of the kaolinite (K) interlayer space is challenging. In this work, a new kaolinite-based nanohybridmaterial (K-NI) was successfully synthesized by grafting on the interlayer aluminol surfaces the ionic liquid, 1-(1-methylnaphthyl)-3-(2-hydroxyethyl) imidazolium chloride (NI), using a guest displacement strategy. A substantial increase of the basal spacing (10.8 Å) was obtained. This is a grafted derivative of kaolinite possessing one of the largest d-values. Washing in water for several days and other vigorous treatments such as sonication showed a minor effect on the integrity of the material. FTIR and 13C NMR confirmed the conservation of the structure of the ionic liquid after the grafting. Thermal analysis confirmed the presence of grafted material and was used to estimate the abundance of the grafted ionic liquid (0.44 mole per mole of kaolinite structural formula, (Al2Si2O5(OH)4)). By using cyclic voltammetry, the permeability of a film of K-NI for the bulky ferricyanide ions was demonstrated. The accumulation of nitrophenolate anions was effective (maximum capacity of 190 μmol/g), but was less important than what was expected due to the steric hindrance of the bulky grafted NI. Although the presence of chloride anions reduced the adsorption capacity, the affinity of the modified kaolinite interlayer space for the nitrophenolate anions was demonstrated. PMID:28850087

  18. Structural and electrochemical properties of succinonitrile-based gel polymer electrolytes: role of ionic liquid addition.

    Science.gov (United States)

    Suleman, Mohd; Kumar, Yogesh; Hashmi, S A

    2013-06-20

    Experimental studies on the novel compositions of gel polymer electrolytes, comprised of plastic crystal succinonitrile (SN) dispersed with pyrrolidinium and imidazolium-based ionic liquids (ILs) entrapped in a host polymer poly(vinylidine fluoride-co-hexafluoropropylene) (PVdF-HFP), are reported. The gel electrolytes are in the form of free-standing films with excellent mechanical, thermal, and electrochemical stability. The introduction of even a small content (~1 wt %) of ionic liquid (1-butyl-1-methylpyrrolidinium bis(trifluoromethyl-sulfonyl)imide (BMPTFSI) or 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMITf) in the PVdF-HFP/SN system (1:4 w/w) enhances the electrical conductivity by 4 orders of magnitude, that is, from ~10(-7) to ~10(-3) S cm(-1) at room temperature. The structural changes due to the entrapment of SN or SN/ILs mixtures and ion-SN-polymer interactions are examined by Fourier transform infrared (FTIR)/Raman spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimmetry (DSC). Various physicochemical properties and fast ion conduction in the gel polymer membranes show their promising characteristics as electrolytes in different ionic devices including supercapacitors.

  19. 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.

  20. Method of making ionic liquid mediated sol-gel sorbents

    Science.gov (United States)

    Malik, Abdul; Shearrow, Anne M.

    2017-01-31

    Ionic liquid (IL)-mediated sol-gel hybrid organic-inorganic materials present enormous potential for effective use in analytical microextraction. One obstacle to materializing this prospect arises from high viscosity of ILs significantly slowing down sol-gel reactions. A method was developed which provides phosphonium-based, pyridinium-based, and imidazolium-based IL-mediated advanced sol-gel organic-inorganic hybrid materials for capillary microextraction. Scanning electron microscopy results demonstrate that ILs can serve as porogenic agents in sol-gel reactions. IL-mediated sol-gel coatings prepared with silanol-terminated polymers provided up to 28 times higher extractions compared to analogous sol-gel coatings prepared without any IL in the sol solution. This study shows that IL-generated porous morphology alone is not enough to provide effective extraction media: careful choice of the organic polymer and the precursor with close sol-gel reactivity must be made to ensure effective chemical bonding of the organic polymer to the created sol-gel material to be able to provide the desired sorbent characteristics.

  1. Surface interactions, corrosion processes and lubricating performance of protic and aprotic ionic liquids with OFHC copper

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa, Tulia; Sanes, José; Jiménez, Ana-Eva [Grupo de Ciencia de Materiales e Ingeniería Metalúrgica, Departamento de Ingeniería de Materiales y Fabricación, Universidad Politécnica de Cartagena, Campus de la Muralla del Mar. C/Doctor Fleming, s/n. 30202-Cartagena (Spain); Bermúdez, María-Dolores, E-mail: mdolores.bermudez@upct.es [Grupo de Ciencia de Materiales e Ingeniería Metalúrgica, Departamento de Ingeniería de Materiales y Fabricación, Universidad Politécnica de Cartagena, Campus de la Muralla del Mar. C/Doctor Fleming, s/n. 30202-Cartagena (Spain)

    2013-05-15

    In order to select possible candidates for use as lubricants or as precursors of surface coatings, the corrosion and surface interactions of oxygen-free high conductivity (OFHC) copper with two new protic (PIL) and four aprotic (APIL) room-temperature ionic liquids have been studied. The PILs, with no heteroatoms in their composition, are the triprotic di[(2-hydroxyethyl)ammonium] succinate (MSu) and the diprotic di[bis-(2-hydroxyethyl)ammonium] adipate (DAd). The four APILs contain imidazolium cations with short or long alkyl chain substituents and reactive anions: 1-ethyl-3-methylimidazolium phosphonate ([EMIM]EtPO{sub 3}H); 1-ethyl-3-methylimidazolium octylsulfate ([EMIM]C{sub 8}H{sub 17}SO{sub 4}); 1-hexyl-3-methylimidazolium tetrafluoroborate ([HMIM]BF{sub 4}) and 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIM]PF{sub 6}). Contact angles between the ionic liquids and OFHC copper surface were measured. Mass and roughness changes of OFHC copper after 168 h in contact with the ionic liquids have been determined. Copper surfaces were studied by XRD, SEM–EDX and XPS surface analysis. FTIR spectra of the liquid phases recovered after being in contact with the copper surface were compared with that of the neat ionic liquids. The lowest corrosion rate is observed for the diprotic ammonium adipate PIL (DAd), which gives low mass and surface roughness changes and forms adsorbed layers on copper, while the triprotic ammonium succinate salt (MSu) produces a severe corrosive attack by reaction with copper to form a blue crystalline solid, which has been characterized by FTIR and thermal analysis (TGA). All imidazolium APILs react with copper, with different results as a function of the anion. As expected, [EMIM]C{sub 8}H{sub 17}SO{sub 4} reacts with copper to form the corresponding copper sulphate salt. [EMIM]EtPO{sub 3}H produces severe corrosion to form a phosphonate–copper soluble phase. [HMIM]BF{sub 4} gives rise to the highest roughness increase of the

  2. 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.

  3. 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.

  4. The role of carbon chain length in the attachment between microbubbles and aqueous solutions of ionic liquid.

    Science.gov (United States)

    Chew, E K; Lee, K Y; Lau, E V

    2017-11-15

    The effects of varying carbon chain lengths (CCLs) and concentrations of aqueous solutions of imidazolium based ionic liquids on bubble particle attachment (BPA) will provide a better understanding in catering for the varying degrees of surface activities in the application of the flotation technology. The general trends of this study should also be applicable to homologous series of other cationic surfactants and ionic liquids. Zeta potentials of small air bubbles and bunker oil drops dispersed in aqueous solutions of n-methylimidazolium chloride ionic liquids (n=0, 2, 3, 6, 8, 10, 12) of concentrations ranging from 1000PPM to 8000PPM, as were interfacial tensions of these solutions with bunker oil (180cst) and contact angles made by air bubbles at interfaces between these solutions and thin layers of bunker oil on flat solid surfaces were investigated. Finally, interparticle forces analysis using the Derjaguin-Landau, Verwey-Overbeek (DLVO) theory is also included. Analysis using the DLVO theory showed attractive forces between the oil particles and micro-bubbles are significantly more prevalent in short CCLs solutions of imidazolium-based ILs in low concentrations, namely [C0mim][Cl] and [C2mim][Cl] at a maximum zeta potential difference of 75.3mV. The results from CA measurements follows similarly whereby low concentrations of ILs with short CCLs were in favor for the bubble-particle attachment process with angles ranging between 93.95° for [C0mim][Cl] and 97.28° for [C2mim][Cl]. IFT which is important in reducing coalescence for the preferential BPA process to occur in flotation decreases with an increase of CCL and concentration of IL. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. "Rigid" Luminescent Soft Materials: Europium-Containing Lyotropic Liquid Crystals Based on Polyoxyethylene Phytosterols and Ionic Liquids.

    Science.gov (United States)

    Yi, Sijing; Wang, Jiao; Feng, Zhenyu; Chen, Xiao

    2017-10-05

    Soft materials of europium β-diketonate complexes constructed in lyotropic liquid crystals (LLCs) mediated by ionic liquids (ILs) are impressive for their excellent luminescence performance and stability. For the aim to further improve their mechanical processability and luminescent tunablility, the polyoxyethylene phytosterols (BPS-n) were introduced here as structure directing agents to prepare relatively "rigid" lamellar luminescent LLCs in 1-butyl-3-methyl-imidazolium hexafluorophosphate by doping europium β-diketonate complexes with different imidazolium counterions. As a result of the solvophobic sterol ring structure of BPS-n, the more effective isolation and confinement effects of europium complexes could be achieved. The longest fluorescence lifetime and the highest quantum efficiency reported so far for europium containing lyotropic organized soft materials were thus obtained. Changing the molecular structures of BPS-n with different oxyethylene chains or doped complexes with imidazolium counterions of different alkyl chain lengths, the spacings of lamellar LLC matrixes and position of dispersed complexes became tunable. The measured luminescent and rheological properties for such composite LLCs showed a dependence on the rigidity and isolation capability afforded by sterol molecules. It was also found that the increase of counterion alkyl chain length would weaken the LLC matrix's confinement and isolation effects and therefore exhibit the deteriorated luminescence performance. The enhanced luminescence efficiency and stability of doped BPS-n LLCs reflected the excellent segregation of europium complexes from each other and therefore the reduced self-quenching process. The obtained results here present the designability of LLC matrixes and their great potential to promote achieving the luminescence tunability of soft materials.

  6. Adsorption of TCDD with 1-butyl-3-methylimidazolium dicyanamide ionic liquid: a combined molecular dynamics simulation and quantum chemistry study.

    Science.gov (United States)

    Pan, Wenxiao; Qi, Yuanyuan; Wang, Ruoxi; Han, Zhe; Zhang, Dongju; Zhan, Jinhua

    2013-04-01

    The effective abatement of flue gas emissions, especially polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), is one of the challenging issues in the field of environmental science currently. Imidazolium-based dicyanamide ionic liquids (ILs) were proposed to have potential in controlling the emissions of PCDD/Fs. However, the relevant mechanism at the molecular level still remains unclear. To address this subject, we here present a combined molecular dynamics (MD) simulation and quantum chemical (QM) study on the adsorption of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the most toxic congener among PCDD/F family, by 1-butyl-3-methylimidazolium dicyanamide IL, a representative imidazolium dicyanoamide ILs, which were demonstrated to possess high capture capability for PCDD/Fs. The MD simulation results show that TCDD molecules can be effectively adsorbed on the IL surface to form a dense layer, but cannot enter the interior of the IL. The results of QM calculations show that the adsorption of TCDDs on the IL surface occurs via intra-molecular hydrogen bond interactions. The calculated interaction energy of the anion with TCDD molecule is two times more than that of the cation, implying that the IL anion dominates the interaction with TCDD molecules, while the cation plays a secondary role. Based on the calculated results, we propose that imidazolium dicyanamide IL films/membranes may be better materials than the corresponding bulk for capturing TCDD. The present theoretical results may be helpful to designing the functional ILs which effectively capture and concentrate PCDD/F compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Ionic smoke detectors

    CERN Document Server

    2002-01-01

    Ionic smoke detectors are products incorporating radioactive material. This article summarises the process for their commercialization and marketing, and how the activity is controlled, according to regulations establishing strict design and production requisites to guarantee the absence of radiological risk associated both with their use and their final handling as conventional waste. (Author)

  8. Resistive sensing of gaseous nitrogen dioxide using a dispersion of single-walled carbon nanotubes in an ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Prabhash [Solidstate Electronics Research Laboratory (SERL), Faculty of Engineering and Technology, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025 (India); Department of Nanoengineering, Samara State Aerospace University, 443086 Samara (Russian Federation); Pavelyev, V.S. [Department of Nanoengineering, Samara State Aerospace University, 443086 Samara (Russian Federation); Patel, Rajan [Center for Interdisciplinary Research in Basic Sciences (CIRBSc), Jamia Millia Islamia, Jamia Nagar, New Delhi 110025 (India); Islam, S.S., E-mail: sislam@jmi.ac.in [Solidstate Electronics Research Laboratory (SERL), Faculty of Engineering and Technology, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025 (India)

    2016-06-15

    Graphical abstract: Ionic liquid ([C6-mim]PF6) used as dispersant agent for SWCNTs: An investigations were carried out to find the structural quality and surface modification for sensor application. - Highlights: • An effective technique based on Ionic liquids (IL) and their use as a dispersant. • Electron microscopy and spectroscopy for structure characterization. • Covalent linkage of ILs with SWNTs and dispersion of SWCNTs. • The IL-wrapped sensing film, capable for detecting trace levels of gas. - Abstract: Single-walled carbon nanotubes (SWCNTs) were dispersed in an imidazolium-based ionic liquid (IL) and investigated in terms of structural quality, surface functionalization and inter-CNT force. Analysis by field emission electron microscopy and transmission electron microscopy shows the IL layer to coat the SWNTs, and FTIR and Raman spectroscopy confirm strong binding of the ILs to the SWNTs. Two kinds of resistive sensors were fabricated, one by drop casting of IL-wrapped SWCNTs, the other by conventional dispersion of SWCNTs. Good response and recovery to NO{sub 2} is achieved with the IL-wrapped SWCNTs material upon UV-light exposure, which is needed because decrease the desorption energy barrier to increase the gas molecule desorption. NO{sub 2} can be detected in the 1–20 ppm concentration range. The sensor is not interfered by humidity due to the hydrophobic tail of PF6 (ionic liquid) that makes our sensor highly resistant to moisture.

  9. Ionic Channels in Thunderclouds

    Science.gov (United States)

    Losseva, T. V.; Fomenko, A. S.; Nemtchinov, I. V.

    2007-12-01

    We proceed to study the formation and propagation of ionic channels in thunderclouds in the framework of the model of the corona discharge wave propagation (Fomenko A.S., Losseva T.V., Nemtchinov I.V. The corona discharge waves in thunderclouds and formation of ionic channels // 2004 Fall Meeting. EOS Trans. AGU. 2004. V. 85. ¹ 47. Suppl. Abstract AE23A-0835.). In this model we proposed a hypothesis that the structure of a thundercloud becomes nonuniform due to corona discharge on the drops and ice particles and formation of ionic channels with higher conductivity than the surrounding air. When the onset strength of corona discharge becomes smaller than the electric field strength the corona discharge increases concentrations of ions in a small part of the cloud (a hot spot). An additional charge at opposite ends of the hot spot forms due to polarization process. The increased electric field initiates corona discharge in other parts of the cloud on ice particles and water drops with smaller sizes. The corona discharge front moves as a wave with the velocity of the order of ion drift and formes a highly conductive channel. We model this non-stationary problem with Poisson equation which is solved simultaneously with a simplified set of kinetic equations for ions, small charged particles and electrons (at high electric fields), including ionization due to electronic impact, attachment and formation of positive ions. By applying 3D numerical simulations we obtain the parameters of formed ionic channels with respect to onset electric fields both from large particles (in hot spot) and from small particles (surrounding hot spot), microscopic currents from particles with different sizes and the external electric field in the cloud. The interaction of ionic channels is also investigated. This work was supported by Russian Foundation of Basic Research (Project No 07-05-00998-à).

  10. A conformational change in the peripheral anionic site of Torpedo californica acetylcholinesterase induced by a bis-imidazolium oxime.

    Science.gov (United States)

    Legler, Patricia M; Soojhawon, Iswarduth; Millard, Charles B

    2015-09-01

    As part of ongoing efforts to design improved nerve agent antidotes, two X-ray crystal structures of Torpedo californica acetylcholinesterase (TcAChE) bound to the bis-pyridinium oxime, Ortho-7, or its experimental bis-imidazolium analogue, 2BIM-7, were determined. Bis-oximes contain two oxime groups connected by a hydrophobic linker. One oxime group of Ortho-7 binds at the entrance to the active-site gorge near Trp279, and the second binds at the bottom near Trp84 and Phe330. In the Ortho-7-TcAChE complex the oxime at the bottom of the gorge was directed towards the nucleophilic Ser200. In contrast, the oxime group of 2BIM-7 was rotated away from Ser200 and the oxime at the entrance induced a significant conformational change in the peripheral anionic site (PAS) residue Trp279. The conformational change alters the surface of the PAS and positions the imidazolium oxime of 2BIM-7 further from Ser200. The relatively weaker binding and poorer reactivation of VX-inhibited, tabun-inhibited or sarin-inhibited human acetylcholinesterase by 2BIM-7 compared with Ortho-7 may in part be owing to the unproductively bound states caught in crystallo. Overall, the reactivation efficiency of 2BIM-7 was comparable to that of 2-pyridine aldoxime methyl chloride (2-PAM), but unlike 2-PAM the bis-imidazolium oxime lacks a fixed charge, which may affect its membrane permeability.

  11. Determination of volatile compounds in cider apple juices using a covalently bonded ionic liquid coating as the stationary phase in gas chromatography.

    Science.gov (United States)

    Pello-Palma, Jairo; González-Álvarez, Jaime; Gutiérrez-Álvarez, María Dolores; Dapena de la Fuente, Enrique; Mangas-Alonso, Juan José; Méndez-Sánchez, Daniel; Gotor-Fernández, Vicente; Arias-Abrodo, Pilar

    2017-04-01

    A chromatographic method for the separation of volatile compounds in Asturian cider apple juices has been developed. For this separation purpose, a monocationic imidazolium-based ionic liquid bearing a reactive terminal iodine atom was synthesized by a quaternization-anion exchange chemical sequence. Next, the gas chromatography (GC) stationary phase was prepared by covalently linking the imidazolium monolith to the reactive silanol groups of the inner capillary wall at 70 °C. This coated GC column exhibited good thermal stability (290 °C), as well as good efficiency (2000 plates/m) in the separation of volatile compounds from Asturian apple cider juices, and was characterized using the Abraham solvation parameter model. The intra-day and inter-day precision of the chromatographic method was evaluated, obtaining relative standard deviations from 3.7 to 12.9% and from 7.4 to 18.0%, respectively. Furthermore, recoveries from 82.5 to 122% were achieved. Graphical Abstract Covalent bonding of an ionic liquid to inner column wall led to a great improvement of the separation efficiencies of stationary phases in gas chromatography.

  12. Growth of Gold Nanosheets and Nanopolyhedra in Pyrrolidinium-Based Ionic Liquids: Investigation of the Cation Effect on the Resulting Morphologies

    Energy Technology Data Exchange (ETDEWEB)

    Bouvy, Claire [ORNL; Baker, Gary A [ORNL; Yin, Hongfeng [ORNL; Dai, Sheng [ORNL

    2010-01-01

    Large gold nanosheets and small gold polyhedra have been successfully synthesized in room-temperature ionic liquids (ILs) by an ionothermal reduction of HAuCl{sub 4} under N{sub 2} atmosphere, without using any additives. The effect of the organic cation on the final morphologies of the gold particles has been studied, and a series of pyrrolidinium-, imidazolium-, and quaternary amine-based ionic liquids have been investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) measurements. Our results show that these ILs favor the anisotropic growth of gold by acting as template agents and that only gold microspheres can be obtained with the IL containing a reductive functionality.

  13. 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.

  14. Effect of Dimethyl Carbonate on the Dynamic Properties and Ionicities of Ionic Liquids with [M(III) (hfip)4 ](-) (M=B, Al) Anions.

    Science.gov (United States)

    Rupp, Alexander B A; Welle, Sabrina; Klose, Petra; Scherer, Harald; Krossing, Ingo

    2015-06-22

    Several ionic liquids (ILs) comprising [B(hfip)4 ](-) [hfip=OCH(CF3 )2 ] or [Al(hfip)4 ](-) anions and imidazolium or ammonium cations were prepared and mixed with up to 270 mol % of dimethyl carbonate (DMC). The viscosities, conductivities, and self-diffusion constants of these mixtures and, where possible, of the neat ILs were measured and compared with common [NTf2 ](-) based ILs and their mixtures with DMC. A tremendous decrease of the viscosities and a likewise increase of the conductivities and diffusion constants can be achieved for all classes of ILs. However, the order of the conductivities is partially reversed in the diffusion data. This is probably due to the low dielectric constant of DMC and the, thus, favored ion pairing, as evidenced, for example, by the calculated ionicities. Altogether, our data show that the chemically robust, but high-melting and more viscous [B(hfip)4 ](-) ILs might be candidates for electrolytes when mixed with suitable molecular solvents. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Bis(1,3-dimethyl-1H-imidazolium hexafluorosilicate methanol 0.33-solvate

    Directory of Open Access Journals (Sweden)

    Maxim V. Borzov

    2013-08-01

    Full Text Available The title compound, 6C5H9N2+·3SiF62−·CH3OH, (I, was prepared by recrystallization of the crude salt from methanol along with solvent-free 2C5H9N2+·SiF62− (II. Crystals of these solvatomorphs can be separated manually. The solvate (I crystallizes in a rare hexagonal space group P6/mcc. Its asymmetric unit comprises one half of an imidazolium cation bisected by the crystallographic m-plane, one-sixth and one-twelfth of two crystallographically independent SiF62– dianions (Si atoms are located on the 3.2 and 6/m inversion centres, and one-twelfth of a methanol molecule (C atoms are situated on the 622 inversion centres, other atoms are disordered between general positions. In (I, all F atoms of 3.2-located SiF62– dianions participate in the formation of symmetry-equivalent contacts to the H atoms of imidazolium fragments, thus forming rod-type ensembles positioned on the -6 axes. These `pillar' rods are, in turn, F...H interlinked through SiF62– dianions disordered around the 6/m centres. The twelvefold disordered methanol molecules are appended to this array by O—H...F hydrogen bonds to the 6/m located SiF62– dianions. In terms of graph-set notation, the first and second level networks in (I are N1 = C22(7[3R44(14]D22(4 and N2 = D22(5 (C—H...O hydrogen bonds are not considered. After locating all symmetrically independent atoms in the cation and anions, there remained a strong (> 3 e Å−3 residual electron density peak located at the 622 inversion centre. Treatment of this pre-refined model with the SQUEEZE procedure in PLATON [Spek (2009. Acta Cryst. D65, 148–155] revealed two voids per unit cell, indicative of the presence of the solvent methanol molecule disordered about the 622 inversion centre.

  16. Nanoscale Ionic Materials

    KAUST Repository

    Rodriguez, Robert

    2008-11-18

    Polymer nanocomposites (nanoparticles dispersed in a polymer matrix) have been the subject of intense research for almost two decades in both academic and industrial settings. This interest has been fueled by the ability of nanocomposites to not only improve the performance of polymers, but also by their ability to introduce new properties. Yet, there are still challenges that polymer nanocomposites must overcome to reach their full potential. In this Research News article we discuss a new class of hybrids termed nanoparticle ionic materials (NIMS). NIMS are organic-inorganic hybrid materials comprising a nanoparticle core functionalized with a covalently tethered ionic corona. They are facilely engineered to display flow properties that span the range from glassy solids to free flowing liquids. These new systems have unique properties that can overcome some of the challenges facing nanocomosite materials. © 2008 WILEY-VCH Verlag GmbH & Co. KGaA.

  17. Super ionic conductive glass

    Science.gov (United States)

    Susman, S.; Volin, K.J.

    Described is an ionically conducting glass for use as a solid electrolyte in a power or secondary cell containing an alkali metal-containing anode and a cathode separated by an alkali metal ion conducting glass having an ionic transference number of unity and the general formula: A/sub 1 + x/D/sub 2-x/3/Si/sub x/P/sub 3 - x/O/sub 12 - 2x/3/, wherein A is a network modifier for the glass and is an alkali metal of the anode, D is an intermediate for the glass and is selected from the class consisting of Zr, Ti, Ge, Al, Sb, Be, and Zn and X is in the range of from 2.25 to 3.0. Of the alkali metals, Na and Li are preferred and of the intermediate, Zr, Ti and Ge are preferred.

  18. 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...

  19. Ionic contamination detection

    Science.gov (United States)

    Benkovich, M. G.

    1994-04-01

    The effectiveness of Meter A and B for detecting ionic contamination was evaluated and compared on the following types of samples: (1) copper panels; (2) printed wiring boards with through-hold components (IC's); (3) printed wiring boards with surface-mounted components; and (4) mixed-technology printed wiring boards (both through-hole and surface-mount components). The extraction efficiency of the two meters was calculated.

  20. Effects of ionic liquid to water ratio as a composite medium for the synthesis of LiFePO4 for battery

    Science.gov (United States)

    Tith, Rany; Dutta, Jaydeep; Jung, Kichang; Martinez-Morales, Alfredo A.

    2017-05-01

    LiFePO4 is a highly researched cathode material that serves as an alternative material for traditional commercial lithiumion batteries such as LiCoO2. Currently, there are a number of different methods to synthesize LiFePO4 including: hydrothermal, solid state, spray pyrolysis, and coprecipitation. Our proposed method has the potential to provide an ecologically friendly and economically competitive way to synthesize LiFePO4 by utilizing ionic liquid and water, as a composite synthesis medium. The addition of water to ionic liquid can be beneficial as it can act as a mineralizer to bring insoluble precursors to form LiFePO4 seed crystals. Furthermore, this method provides the possibility of recycling the ionic liquid for repeated synthesis processes. In this work, we study the effects of ionic liquid to water ratio on the crystallinity and morphology of the synthesized material. Our group was able to conclude a reaction medium utilizing a ratio of equal parts of 1-ethyl-3-methyl imidazolium trifluoromethane sulfonate (EMIM Otf) and water, or a slightly favored ionic liquid ratio, increases the efficacy of the synthesis route. Crystallinity and purity was determined by X-ray diffraction (XRD), scanning electron microscopy (SEM) was used to determine morphology and crystal sizes, and energy dispersion spectroscopy (EDX) was used for elemental analysis.

  1. Highly Conductive Ionic-Liquid Gels Prepared with Orthogonal Double Networks of a Low-Molecular-Weight Gelator and Cross-Linked Polymer.

    Science.gov (United States)

    Kataoka, Toshikazu; Ishioka, Yumi; Mizuhata, Minoru; Minami, Hideto; Maruyama, Tatsuo

    2015-10-21

    We prepared a heterogeneous double-network (DN) ionogel containing a low-molecular-weight gelator network and a polymer network that can exhibit high ionic conductivity and high mechanical strength. An imidazolium-based ionic liquid was first gelated by the molecular self-assembly of a low-molecular-weight gelator (benzenetricarboxamide derivative), and methyl methacrylate was polymerized with a cross-linker to form a cross-linked poly(methyl methacrylate) (PMMA) network within the ionogel. Microscopic observation and calorimetric measurement revealed that the fibrous network of the low-molecular-weight gelator was maintained in the DN ionogel. The PMMA network strengthened the ionogel of the low-molecular-weight gelator and allowed us to handle the ionogel using tweezers. The orthogonal DNs produced ionogels with a broad range of storage elastic moduli. DN ionogels with low PMMA concentrations exhibited high ionic conductivity that was comparable to that of a neat ionic liquid. The present study demonstrates that the ionic conductivities of the DN and single-network, low-molecular-weight gelator or polymer ionogels strongly depended on their storage elastic moduli.

  2. Separation of aromatic solvents from oil refinery reformates by a newly designed ionic liquid using gas chromatography with flame ionization detection.

    Science.gov (United States)

    Bahadur, Indra; Mabaso, Mbongeni; Redhi, Gan; Singh, Prashant; Kumar, Sudharsan; Moodley, Kandasamy

    2015-03-01

    The aim of this study was to determine whether the new ionic liquid, N,N-dimethyl-2-oxopyrrolidonium iodide, synthesized in our laboratory is a suitable solvent for the separation of aromatic components benzene, toluene, ethylbenzene, and xylenes from petroleum mixtures (reformates) in liquid-liquid extraction. In pursuance of the above aim, a method to extract all components of a mixture, containing four aromatic components simultaneously, was developed. A new ionic liquid and a previously used liquid were compared for their extraction abilities. These ionic liquids were, respectively, N,N-dimethyl-2-oxopyrrolidinium iodide and 1-ethyl-3-methyl imidazolium ethyl sulfate. The concentrations of each benzene, toluene, ethylbenzene, and xylenes component in the extract and raffinate phases were measured by gas chromatography with flame ionization detection as volume percent to determine the extraction ability of the ionic liquids. The results obtained for both the reformate samples and model mixtures indicated that the new ionic liquid was effective as an extracting solvent for the recovery of aromatic components from reformates. Also the analysis results, using gas chromatography with flame ionization detection, for the reformate samples were as good as the results obtained by a local oil refinery. The extraction results also show that the developed method is very suitable for the separation and analysis of aromatic components in reformates. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Conformational Properties of a Polymer in an Ionic Liquid: Computer Simulations and Integral Equation Theory of a Coarse-Grained Model.

    Science.gov (United States)

    Choi, Eunsong; Yethiraj, Arun

    2015-07-23

    We study the conformational properties of polymers in room temperature ionic liquids using theory and simulations of a coarse-grained model. Atomistic simulations have shown that single poly(ethylene oxide) (PEO) molecules in the ionic liquid 1-butyl 3-methyl imidazolium tetrafluoroborate ([BMIM][BF4]) are expanded at room temperature (i.e., the radius of gyration, Rg), scales with molecular weight, Mw, as Rg ∼ Mw(0.9), instead of the expected self-avoiding walk behavior. The simulations were restricted to fairly short chains, however, which might not be in the true scaling regime. In this work, we investigate a coarse-grained model for the behavior of PEO in [BMIM][BF4]. We use existing force fields for PEO and [BMIM][BF4] and Lorentz–Berthelot mixing rules for the cross interactions. The coarse-grained model predicts that PEO collapses in the ionic liquid. We also present an integral equation theory for the structure of the ionic liquid and the conformation properties of the polymer. The theory is in excellent agreement with the simulation results. We conclude that the properties of polymers in ionic liquids are unusually sensitive to the details of the intermolecular interactions. The integral equation theory is sufficiently accurate to be a useful guide to computational work.

  4. Course on Ionic Channels

    CERN Document Server

    1986-01-01

    This book is based on a series of lectures for a course on ionic channels held in Santiago, Chile, on November 17-20, 1984. It is intended as a tutorial guide on the properties, function, modulation, and reconstitution of ionic channels, and it should be accessible to graduate students taking their first steps in this field. In the presentation there has been a deliberate emphasis on the spe­ cific methodologies used toward the understanding of the workings and function of channels. Thus, in the first section, we learn to "read" single­ channel records: how to interpret them in the theoretical frame of kinetic models, which information can be extracted from gating currents in re­ lation to the closing and opening processes, and how ion transport through an open channel can be explained in terms of fluctuating energy barriers. The importance of assessing unequivocally the origin and purity of mem­ brane preparations and the use of membrane vesicles and optical tech­ niques in the stUGY of ionic channels a...

  5. Synthesis of imidazolium-containing mono-methacrylates as polymerizable antibacterial agents for acrylic bone cements.

    Science.gov (United States)

    Zhu, Wenbin; Liu, Fang; He, Jingwei

    2017-10-01

    With the aim to prepare antibacterial acrylic bone cements, a series of imidazolium-containg mono-methacrylates with N-alkyl chain length varied from 10 to 18 (MEIM-x) were synthesized as polymerizable antibacterial agents through a two-step reaction. The structures of the monomers were confirmed by 1H NMR. Methyl methacrylate in the liquid compoent of cements was partially replaced by MEIM-x to prepare bone cements with 5wt% of MEIM-x. Properties of prepared cements like antibacterial activity, doughing time, curing parameters including maximum temperature (Tmax) and setting time (tset), flexual strength (FS) and modulus (FM), compressive strength (CS) and fluid uptake (FU) in Ringer's solution were investigated. Acrylic bone cement without any MEIM-x was used as control. Compared with the control cement, MEIM-x-containing cements had shorter doughing time, lower Tmax, same or longer tset, and higher FU. Though MEIM-x could endow cements with strong antibacterial activity, it could reduce mechanical properties of bone cements. Therefore, further study should be taken to optimize the content of MEIM-x in cement which could supply sufficient antibacterial activity and maintain mechanical performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Hybrid electrolytes based on ionic liquids and amorphous porous silicon nanoparticles: Organization and electrochemical properties

    KAUST Repository

    Tchalala, Mohammed

    2017-05-06

    Ionic liquids (ILs) and ionic liquid-nanoparticle (IL-NP) hybrid electrolytes have garnered a lot of interest due to their unique properties that stimulate their use in various applications. Herein, we investigate the electrochemical and photo-physical properties of organic-inorganic hybrid electrolytes based on three imidazolium-based ionic liquids, i.e., 1-buthyl-3-methylimidazolium thiocyanate ([bmim] [SCN]), 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim] [BF4]) and 1-buthyl-3-methylimidazolium acetate ([bmim] [Ac]) that are covalently tethered to amorphous porous silicon nanoparticles (ap-Si NPs). We found that the addition of ap-Si NPs confer to the ILs a pronounced boost in the electrocatalytic activity, and in mixtures of ap-Si NPs and [bmim] [SCN], the room-temperature current transport is enhanced by more than 5 times compared to bare [bmim] [SCN]. A detailed structural investigation by transmission electron microscope (TEM) showed that the ap-Si NPs were well dispersed, stabilized and highly aggregated in [bmim] [SCN], [emim] [BF4] and [bmim] [Ac] ILs, respectively. These observations correlate well with the enhanced current transport observed in ap-Si NPs/[bmim] [SCN] evidenced by electrochemical measurements. We interpreted these observations by the use of UV–vis absorbance, photoluminescence (PL), FTIR and solid-state NMR spectroscopy. We found that the ap-Si NPs/[bmim] [SCN] hybrid stands out due to its stability and optical transparency. This behavior is attributed to the iron(III) thiocyanate complexion as per the experimental findings. Furthermore, we found that the addition of NPs to [emim] [BF4] alters the equilibrium of the IL, which consequently improved the stability of the NPs through intermolecular interactions with the two ionic layers (anionic and cationic layers) of the IL. While in the case of [bmim] [Ac], the dispersion of ap-Si NPs was restrained because of the high viscosity of this IL.

  7. 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.

  8. 3-(1-Methyl-3-imidazoliopropanesulfonate: a precursor to a Brønsted acid ionic liquid

    Directory of Open Access Journals (Sweden)

    Hugh C. De Long

    2010-03-01

    Full Text Available The title compound, C7H12N2O3S, is a zwitterion precursor to a Brønsted acid ionic liquid with potential as an acid catalyst. The C—N—C—C torsion angle of 100.05 (8° allows the positively charged imidazolium head group and the negatively charged sulfonate group to interact with neighboring zwitterions, forming a C—H...O hydrogen-bonding network; the shortest among these interactions is 2.9512 (9 Å. The C—H...O interactions can be described by graph-set notation as two R22(16 and one R22(5 hydrogen-bonded rings.

  9. Direct Production of Furfural in One-pot Fashion from Raw Biomass Using Brønsted Acidic Ionic Liquids.

    Science.gov (United States)

    Matsagar, Babasaheb M; Hossain, Shahriar A; Islam, Tofazzal; Alamri, Hatem R; Alothman, Zeid A; Yamauchi, Yusuke; Dhepe, Paresh L; Wu, Kevin C-W

    2017-10-18

    The conversion of raw biomass into C5-sugars and furfural was demonstrated with the one-pot method using Brønsted acidic ionic liquids (BAILs) without any mineral acids or metal halides. Various BAILs were synthesized and characterized using NMR, FT-IR, TGA, and CHNS microanalysis and were used as the catalyst for raw biomass conversion. The remarkably high yield (i.e. 88%) of C5 sugars from bagasse can be obtained using 1-methyl-3(3-sulfopropyl)-imidazolium hydrogen sulfate ([C3SO3HMIM][HSO4]) BAIL catalyst in a water medium. Similarly, the [C3SO3HMIM][HSO4] BAIL also converts the bagasse into furfural with very high yield (73%) in one-pot method using a water/toluene biphasic solvent system.

  10. Automated evaluation of pharmaceutically active ionic liquids' (eco)toxicity through the inhibition of human carboxylesterase and Vibrio fischeri.

    Science.gov (United States)

    Costa, Susana P F; Justina, Vanessa D; Bica, Katharina; Vasiloiu, Maria; Pinto, Paula C A G; Saraiva, M Lúcia M F S

    2014-01-30

    The toxicity of 16 pharmaceutical active ionic liquids (IL-APIs) was evaluated by automated approaches based on sequential injection analysis (SIA). The implemented bioassays were centered on the inhibition of human carboxylesterase 2 and Vibrio fischeri, in the presence of the tested compounds. The inhibitory effects were quantified by calculating the inhibitor concentration required to cause 50% of inhibition (EC50). The EC50 values demonstrated that the cetylpyridinium group was one of the most toxic cations and that the imidazolium group was the less toxic. The obtained results provide important information about the safety of the studied IL-APIs and their possible use as pharmaceutical drugs. The developed automated SIA methodologies are robust screening bioassays, and can be used as a generic tools to identify the (eco)toxicity of the structural elements of ILs, contributing to a sustainable development of drugs. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Functionalized dicationic ionic liquids: Green and efficient ...

    Indian Academy of Sciences (India)

    A new approach using alkyl sulfonated functional- ized ILs has drawn more efforts due to their acidic prop- erties and water solubility. Recently some imidazolium and pyridinium based acidic ILs were used as catalyst to pre- pare phthalate plasticizers.9,18 Meanwhile, multifunctional. ILs especially dicationic ILs (DCILs) are ...

  12. Nanofriction of Graphene/Ionic Liquid-Infused Block Copolymer Homoporous Membranes.

    Science.gov (United States)

    An, Rong; Fan, Pengpeng; Yan, Nina; Ji, Qingmin; Sunkulp, Goel; Wang, Yong

    2017-10-24

    We have infused graphene/ionic liquid into block copolymer homoporous membranes (HOMEs), which have highly ordered uniform cylindrical nanopores, to form compact, dense, and continuous graphene/ionic liquid (Gr/IL) lubricating layers at interfaces, enabling a reduction in the friction coefficient. Raman and XPS analyses, confirmed the parallel alignment of the cation of ILs on graphene by the π-π stacking interaction of the imidazolium ring with the graphene layer. This alignment loosens the lattice spacing of Gr in Gr/ILs, leading to a larger lattice spacing of 0.36 nm in Gr of Gr/ILs hybrids than the pristine Gr (0.33 nm). The loose graphene layers, which are caused by the coexistence of graphene and ILs, would make the sliding easier, and favor the lubrication. An increase in the friction coefficient was observed on ILs-infused block copolymer HOMEs, as compared to Gr/ILs-infused ones, due to the absence of Gr and the unstably formed ILs film. Gr/ILs-infused block copolymer HOMEs also exhibit much smaller residual indentation depth and peak indentation depth in comparison with ILs-infused ones. This indicates that the existence of stably supported Gr/ILs hybrid liquid films aids the reduction of the friction coefficient by preventing the thinning of the lubricant layer and exposure of the underlying block copolymer HOMEs.

  13. Modification of carbon nanotubes with fluorinated ionic liquid for improving processability of fluoro-ethylene-propylene

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Hongyang; Chu, Benjamin; Hsiao, Benjamin S.

    2017-02-01

    Fluorinated ionic liquid (F-IL), 1-(3-perfluorooctylpropyl)-3-methylimidazolium bis(perfluoroethylsufonyl)amine, had been successfully prepared and employed to modify multi-wall carbon nanotubes (MWCNTs) for improving the processability of fluoro-ethylene-propylene (FEP). The thermally decomposed temperature of F-IL was higher than 350 °C measured by thermal gravimetric analysis (TGA) which indicated that the fluorinated ionic liquid could be suitable for melting blend with FEP (blending at 290 °C) by a twin-screw extruder. Through “cation-π” interaction between the imidazolium cation of F-IL and the graphene surface of MWCNTs, MWCNTs can be modified with F-IL and used as nanofillers to improve the dispersity of MWCNTs in fluorocopolymer FEP verified by SEM images of the FEP nanocomposite. The structural characterization and mechanical property of FEP nanocomposite during the deformation were investigated by tensile experiments and simultaneous time-resolved wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) techniques.

  14. Ionic Liquid-Tethered Nanoparticle Suspensions: A Novel Class of Ionogels

    KAUST Repository

    Moganty, Surya S.

    2012-04-10

    We report a novel class of silica ionogels created by dispersing silica nanoparticles densely grafted with the ionic liquid (IL) 1-trimethoxysilyl propyl-3-methyl-imidazolium bis- (trifluoromethylsulfonyl) imide (SpmImTSFI) in a 1-butyl-3- methyl-pyrrolidinium bis(trifluoromethylsulfonyl) imide (BmpyrTFSI) IL host. We find that over the entire range of nanoparticle volume fractions studied the systems exist as stable suspensions of SiO 2-SpmImTFSI in the BmpyrTFSI host. Remarkably, we also find that addition of even minute quantities of SiO 2-SpmImTFSI to the BmpyrTFSI IL suppresses crystallization of the host. The resulting disordered hybrid fluids exhibit liquid-like transport properties over a vastly extended temperature range; they open the way for facile synthesis of ILs with extended operating temperature windows. These observations are explained in terms of ionic coupling of the nanoparticle-tethered and free TFSI anions, which is thought to suppress crystallization of BmpyrTFSI. © 2012 American Chemical Society.

  15. Straightforward approach to graft bioactive polysaccharides onto polyurethane surfaces using an ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Bigot, Sandra [Normandie Université, INSA de Rouen, CNRS UMR 6270 FR 3038, Avenue de l’université BP08, 76801 Saint-Etienne du Rouvray (France); Louarn, Guy [Institut des Matériaux Jean Rouxel (IMN), UMR 6502, CNRS-Université de Nantes, 2 rue de la Houssinière, BP 32229, 44322 Nantes (France); Kébir, Nasreddine, E-mail: nasreddine.kebir@insa-rouen.fr [Normandie Université, INSA de Rouen, CNRS UMR 6270 FR 3038, Avenue de l’université BP08, 76801 Saint-Etienne du Rouvray (France); Burel, Fabrice [Normandie Université, INSA de Rouen, CNRS UMR 6270 FR 3038, Avenue de l’université BP08, 76801 Saint-Etienne du Rouvray (France)

    2014-09-30

    Graphical abstract: - Highlights: • Development of a facile chemical process for PU surface derivatization. • Direct grafting of seaweed polysaccharides onto isothiocyanated PU surface. • Use of a selected ionic liquid as solvent and catalyst. - Abstract: Surface properties directly affect the performance of a material in a biological environment. In this study, the goal was to develop a simple procedure allowing the grafting of antibacterial polysaccharides onto biomedical grade polyurethanes (e.g. Tecothane{sup ®}). Thus, a straightforward chemical pathway involving an isothiocyanate–alcohol reaction in an ionic liquid (IL) was developed. PU isothiocyanted surfaces (PU–NCS) were first prepared by reacting p-phenylene diisothiocyanate with the surface urethane groups. Then, unmodified bioactive seaweed polysaccharides were directly grafted onto the surface, in mild conditions. The selected IL, i.e. 1-ethyl-3-methyl imidazolium phosphate, was of particular interest since this liquid worked as solvent for p-phenylene diisothiocyanate and the polysaccharides and as catalyst for the grafting reactions. Successful grafting of the different polysaccharides was attested by changes in the surface functional groups, using X-ray photoelectron spectroscopy (XPS). Atomic force microscopy (AFM) showed that polysaccharide grafting, slightly increased the surface roughness from 1.9 to more than 7 nm. Contact angle with water decreased from 88° (for native PU) to around 75° after polysaccharide grafting, attesting a more hydrophilic surface. This procedure would be transposed to the grafting onto PU surfaces of any macromolecule of interest bearing hydroxyl, thiol or amine groups.

  16. Which controls the depolymerization of cellulose in ionic liquids: the solid acid catalyst or cellulose?

    Science.gov (United States)

    Rinaldi, Roberto; Meine, Niklas; vom Stein, Julia; Palkovits, Regina; Schüth, Ferdi

    2010-02-22

    Cellulose is a renewable and widely available feedstock. It is a biopolymer that is typically found in wood, straw, grass, municipal solid waste, and crop residues. Its use as raw material for biofuel production opens up the possibility of sustainable biorefinery schemes that do not compete with food supply. Tapping into this feedstock for the production of biofuels and chemicals requires--as the first-step--its depolymerization or its hydrolysis into intermediates that are more susceptible to chemical and/or biological transformations. We have shown earlier that solid acids selectively catalyze the depolymerization of cellulose solubilized in 1-butyl-3-methylimidazolium chloride (BMIMCl) at 100 degrees C. Here, we address the factors responsible for the control of this reaction. Both cellulose and solid acid catalysts have distinct and important roles in the process. Describing the depolymerization of cellulose by the equivalent number of scissions occurring in the cellulosic chains allows a direct correlation between the product yields and the extent of the polymer breakdown. The effect of the acid strength on the depolymerization of cellulose is discussed in detail. Practical aspects of the reaction, concerning the homogeneous nature of the catalysis in spite of the use of a solid acid catalyst, are thoroughly addressed. The effect of impurities present in the imidazolium-based ionic liquids on the reaction performance, the suitability of different ionic liquids as solvents, and the recyclability of Amberlyst 15DRY and BMIMCl are also presented.

  17. Magnetic ionic liquids: synthesis and characterization; Liquidos ionicos magneticos: sintese e caracterizacao

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, Anderson M.M.S.; Parize, Alexandre L.; Oliveira, Vanda M.; Neto, Brenno A.D.; Rubim, Joel C. [Universidade de Brasilia (LMC/IQ/UnB), DF (Brazil). Inst. de Quimica. Lab de Materiais e Combustiveis

    2010-07-01

    The synthesis of magnetic ionic liquids (MILs) based on the stable dispersions of magnetic nanoparticles (MNPs) of {gamma}-Fe{sub 2}O{sub 3}, Fe{sub 3}O{sub 4}, and CoFe{sub 2}O{sub 4} in the ionic liquid 1-n-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMI.NTf{sub 2}) is reported. The MNPs were obtained by the coprecipitation method. The surface of the {alpha}-Fe{sub 2}O{sub 3}, Fe{sub 3}O{sub 4}, and CoFe{sub 2}O{sub 4} MNPs with mean sizes (XRD) of 9.3, 12.3, and 11.0 nm, respectively were functionalized by 1-n-butyl-3-(3'-trimethoxypropylsilane)- imidazolium chloride. The non functionalized and functionalized MNPs were further characterized by Raman, FTIR-ATR, and FTNIR spectroscopy and by TGA. The stability of the MILs was assigned to the formation of at least one monolayer of the surface modifier agent that mimics the structure of the BMI.NTf{sub 2} IL. (author)

  18. Nanocomposites Based on Luminescent Colloidal Nanocrystals and Polymeric Ionic Liquids towards Optoelectronic Applications

    Directory of Open Access Journals (Sweden)

    Annamaria Panniello

    2014-01-01

    Full Text Available Polymeric ionic liquids (PILs are an interesting class of polyelectrolytes, merging peculiar physical-chemical features of ionic liquids with the flexibility, mechanical stability and processability typical of polymers. The combination of PILs with colloidal semiconducting nanocrystals leads to novel nanocomposite materials with high potential for batteries and solar cells. We report the synthesis and properties of a hybrid nanocomposite made of colloidal luminescent CdSe nanocrystals incorporated in a novel ex situ synthesized imidazolium-based PIL, namely, either a poly(N-vinyl-3-butylimidazolium hexafluorophosphate or a homologous PIL functionalized with a thiol end-group exhibiting a chemical affinity with the nanocrystal surface. A capping exchange procedure has been implemented for replacing the pristine organic capping molecules of the colloidal CdSe nanocrystals with inorganic chalcogenide ions, aiming to disperse the nano-objects in the PILs, by using a common polar solvent. The as-prepared nanocomposites have been studied by TEM investigation, UV-Vis, steady-state and time resolved photoluminescence spectroscopy for elucidating the effects of the PIL functionalization on the morphological and optical properties of the nanocomposites.

  19. Nanostructuration of ionic liquids: impact on the cation mobility. A multi-scale study.

    Science.gov (United States)

    Ferdeghini, Filippo; Berrod, Quentin; Zanotti, Jean-Marc; Judeinstein, Patrick; Sakai, Victoria García; Czakkel, Orsolya; Fouquet, Peter; Constantin, Doru

    2017-02-02

    When probed at the macroscopic scale, Ionic Liquids (ILs) behave as highly dissociated (i.e. strong) electrolytes while, at the molecular scale, they show clear characteristics of weak ionic solutions. The multi-scale analysis we report in this paper reconciles these apparently at odds behaviors. We investigate by quasi-elastic neutron scattering (QENS) and neutron spin-echo (NSE), the nanometer/nanosecond dynamics of OMIM-BF4, an imidazolium-based IL showing strong nanostructuration. We also probe the same IL on the microscopic (μm and ms) scale by pulsed field gradient NMR. To interpret the neutron data, we introduce a new physical model to account for the dynamics of the side-chains and for the diffusion of the whole molecule. This model describes the observables over the whole and unprecedented investigated spatial ([0.15-1.65] Å(-1)) and time ([0.5-2000] ps) ranges. We arrive at a coherent and unified structural/dynamical description of the local cation dynamics: a localized motion within the IL nanometric domains is combined with a genuine long-range translational motion. The QENS, NSE and NMR experiments describe the same long-range translational process, but probed at different scales. The associated diffusion coefficients are more than one order of magnitude different. We show how this apparent discrepancy is a manifestation of the IL nanostructuration.

  20. Polymerizable Ionic Liquid Crystals Comprising Polyoxometalate Clusters toward Inorganic-Organic Hybrid Solid Electrolytes

    Directory of Open Access Journals (Sweden)

    Takeru Ito

    2017-07-01

    Full Text Available Solid electrolytes are crucial materials for lithium-ion or fuel-cell battery technology due to their structural stability and easiness for handling. Emergence of high conductivity in solid electrolytes requires precise control of the composition and structure. A promising strategy toward highly-conductive solid electrolytes is employing a thermally-stable inorganic component and a structurally-flexible organic moiety to construct inorganic-organic hybrid materials. Ionic liquids as the organic component will be advantageous for the emergence of high conductivity, and polyoxometalate, such as heteropolyacids, are well-known as inorganic proton conductors. Here, newly-designed ionic liquid imidazolium cations, having a polymerizable methacryl group (denoted as MAImC1, were successfully hybridized with heteropolyanions of [PW12O40]3− (PW12 to form inorganic-organic hybrid monomers of MAImC1-PW12. The synthetic procedure of MAImC1-PW12 was a simple ion-exchange reaction, being generally applicable to several polyoxometalates, in principle. MAImC1-PW12 was obtained as single crystals, and its molecular and crystal structures were clearly revealed. Additionally, the hybrid monomer of MAImC1-PW12 was polymerized by a radical polymerization using AIBN as an initiator. Some of the resulting inorganic-organic hybrid polymers exhibited conductivity of 10−4 S·cm−1 order under humidified conditions at 313 K.

  1. Quantifying and controlling the cation uptake upon hydrated ionic liquid-induced swelling of polyelectrolyte multilayers.

    Science.gov (United States)

    Parveen, N; Schönhoff, M

    2017-03-08

    Controlling the uptake of specific ions in polyelectrolyte multilayers is of interest for various fields of application. Here, we quantify the amount of cation of an ionic liquid, namely 1,3-bis(cyanomethyl)imidazolium chloride, incorporated into polyelectrolyte multilayers upon contact with an ionic liquid solution. The ion partition equilibrium is determined depending on concentration in solution, employing attenuated total reflection infrared spectroscopy. Generating an excess charge in multilayers by post-preparative manipulation of their charge balance, one can control the incorporated amount. Three multilayer systems are assembled for this purpose, i.e., PSS/PDADMAC, PSS/PAH and PAA/PDADMAC, employing poly(styrene sulfonate) (PSS), poly(diallyldimethylammonium chloride) (PDADMAC), poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA). The charge balance of the latter two films is manipulated by an external pH stimulus generating an excess positive or negative internal charge, respectively. The concentration of cations in PEM amounts to 30% to 100% of the bulk concentration and scales as PAA/PDADMAC > PSS/PDADMAC > PSS/PAH. Thus, post-preparative pH treatment may be a future tool to create ion-conductive polymer gel films with a desired concentration of small cations.

  2. The Influence of Silica Nanoparticles on Ionic Liquid Behavior: A Clear Difference between Adsorption and Confinement

    Directory of Open Access Journals (Sweden)

    Guozhong Wu

    2013-10-01

    Full Text Available The phase behaviors of ionic liquids (ILs confined in nanospace and adsorbed on outer surface of nanoparticles are expected to be different from those of the bulk. Anomalous phase behaviors of room temperature ionic liquid tributylhexadecylphosphonium bromide (P44416Br confined in ordered mesoporous silica nanoparticles with average pore size 3.7 nm and adsorbed on outer surface of the same silica nanoparticles were reported. It was revealed that the melting points (Tm of confined and adsorbed ILs depressed significantly in comparison with the bulk one. The Tm depressions for confined and adsorbed ILs are 8 °C and 14 °C, respectively. For comparison with the phase behavior of confined P44416Br, 1-butyl-3-methylimidazolium bromide (BmimBr was entrapped within silica nanopores, we observed an enhancement of 50 °C in Tm under otherwise similar conditions. The XRD analysis indicates the formation of crystalline-like phase under confinement, in contrast to the amorphous phase in adsorbed IL. It was confirmed that the behavior of IL has clear difference. Moreover, the complex π-π stacking and H-bonding do not exist in the newly proposed phosphonium-based IL in comparison with the widely studied imidazolium-based IL. The opposite change in melting point of P44416Br@SiO2 and BmimBr@SiO2 indicates that the cationic species plays an important role in the variation of melting point.

  3. Probing the microscopic structural organization of neat ionic liquids (ILs) and ionic liquid-based gels through resonance energy transfer (RET) studies.

    Science.gov (United States)

    Majhi, Debashis; Sarkar, Moloy

    2017-08-30

    With the aim to understand the role of the ionic constituents of ionic liquids (ILs) in their structural organization, resonance energy transfer (RET) studies between ionic liquids (donor) and rhodamine 6G (acceptor) have been investigated. RET studies have been exploited for the present investigation due to the fact that the said process is extremely sensitive to the distance, and a change in the donor-acceptor distance due to a change in the structural organization can be probed. Basically, steady state and time-resolved fluorescence measurements have been carried out in two different sets of ILs, where in one set (1-ethyl-3-methyl imidazolium alkyl sulfate) the alkyl side chain length on the anionic moiety is systematically varied and in the other set variation is done on the cation (aromatic and nonaromatic). The data related to the RET events have been analyzed in light of Förster theory. A clear rise time in the fluorescence intensity decay profile of the acceptor has unequivocally established the RET process between the donor and acceptor. Interestingly, the rise times and energy transfer efficiencies are also observed to vary with a variation in the alkyl chain length as well as the nature of the cations. More interestingly, the donor-acceptor distance (R DA ) is observed to increase from 35.0 Å to 47.5 Å upon increasing the anion chain length from ethyl to octyl. However, R DA is found to decrease (40.5 Å to 34.9 Å) upon going from 1-methyl-3-butylimidazolium to 1-butyl-1-methylpyrrolidinium cations. The variation of the relevant RET parameters for the two sets of ILs has been rationalized by considering the change in the structural organization of the respective set of ILs. Additionally, observation of the RET process also in an IL-based gel system indicates the potential use of this fluorescent gel material for future applications.

  4. Elucidating interactions and conductivity of newly synthesised low bandgap polymer with protic and aprotic ionic liquids.

    Directory of Open Access Journals (Sweden)

    Pankaj Attri

    Full Text Available In this paper, we have examined the conductivity and interaction studies of ammonium and imidazolium based ionic liquids (ILs with the newly synthesised low bandgap polymer (Poly(2-heptadecyl-4-vinylthieno[3,4-d]thiazole (PHVTT. Use of low bandgap polymers is the most suitable way to harvest a broader spectrum of solar radiations for solar cells. But, still there is lack of most efficient low bandgap polymer. In order to solve this problem, we have synthesised a new low bandgap polymer and investigated its interaction with the ILs to enhance its conductivity. ILs may undergo almost unlimited structural variations; these structural variations have attracted extensive attention in polymer studies. The aim of present work is to illustrate the state of art progress of implementing the interaction of ILs (protic and aprotic ILs with newly synthesised low bandgap polymer. In addition to this, our UV-Vis spectroscopy, confocal Raman spectroscopy and FT-IR spectroscopy results have revealed that all studied ILs (tributylmethylammonium methyl sulfate ([N1444][MeSO4] from ammonium family and 1-methylimidazolium chloride ([Mim]Cl, and 1-butyl-3-methylimidazolium chloride ([Bmim]Cl from imidazolium family have potential to interact with polymer. Our semi empirical calculation with help of Hyperchem 7 shows that protic IL ([Mim]Cl interacts strongly with the low bandgap polymer through the H-bonding. Further, protic ILs shows enhanced conductivity than aprotic ILs in association with low bandgap polymer. This study provides the combined effect of low bandgap polymer and ILs that may generate many theoretical and experimental opportunities.

  5. Thermophysical and Electrochemical Properties of Ethereal Functionalised Cyclic Alkylammonium-based Ionic Liquids as Potential Electrolytes for Electrochemical Applications.

    Science.gov (United States)

    Neale, Alex R; Murphy, Sinead; Goodrich, Peter; Hardacre, Christopher; Jacquemin, Johan

    2017-08-05

    A series of hydrophobic room temperature ionic liquids (ILs) based on ethereal functionalised pyrrolidinium, piperidinium and azepanium cations bearing the bis[(trifluoromethyl)sulfonyl]imide, [TFSI](-) , anion were synthesized and characterized. Their physicochemical properties such as density, viscosity and electrolytic conductivity, and thermal properties including phase transition behaviour and decomposition temperature have been measured. All of the ILs showed low melting point, low viscosity and good conductivity and the latter properties have been discussed in terms of the IL fragility, an important electrolyte feature of the transport properties of glass-forming ILs. Furthermore, the studied [TFSI](-) -based ILs generally exhibit good electrochemical stabilities and, by coupling electrochemical experiments and DFT calculations, the effect of ether functionalisation at the IL cation on the electrochemical stability of the IL is discussed. Preliminary investigations into the Li-redox chemistry at a Cu working electrode are also reported as a function of ether-functionality within the pyrrolidinium-based IL family. Overall, the results show that these ionic liquids are suitable for electrochemical devices such as battery systems, fuel cells or supercapacitors. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  6. 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.

  7. Prediction of activity coefficients at infinite dilution for organic solutes in ionic liquids by artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Nami, Faezeh [Department of Chemistry, Shahid Beheshti University, G.C., Evin-Tehran 1983963113 (Iran, Islamic Republic of); Deyhimi, Farzad, E-mail: f-deyhimi@sbu.ac.i [Department of Chemistry, Shahid Beheshti University, G.C., Evin-Tehran 1983963113 (Iran, Islamic Republic of)

    2011-01-15

    To our knowledge, this work illustrates for the first time the ability of artificial neural network (ANN) to predict activity coefficients at infinite dilution for organic solutes in ionic liquids (ILs). Activity coefficient at infinite dilution ({gamma}{sup {infinity}}) is a useful parameter which can be used for the selection of effective solvent in the separation processes. Using a multi-layer feed-forward network with Levenberg-Marquardt optimization algorithm, the resulting ANN model generated activity coefficient at infinite dilution data over a temperature range of 298 to 363 K. The unavailable input data concerning softness (S) of organic compounds (solutes) and dipole moment ({mu}) of ionic liquids were calculated using GAMESS suites of quantum chemistry programs. The resulting ANN model and its validation are based on the investigation of up to 24 structurally different organic compounds (alkanes, alkenes, alkynes, cycloalkanes, aromatics, and alcohols) in 16 common imidazolium-based ionic liquids, at different temperatures within the range of 298 to 363 K (i.e. a total number of 914 {gamma}{sub Solute}{sup {infinity}}for each IL data point). The results show a satisfactory agreement between the predicted ANN and experimental data, where, the root mean square error (RMSE) and the determination coefficient (R{sup 2}) of the designed neural network were found to be 0.103, 0.996 for training data and 0.128, 0.994 for testing data, respectively.

  8. A Spectral-SAR Model for the Anionic-Cationic Interaction in Ionic Liquids: Application to Vibrio fischeri Ecotoxicity

    Directory of Open Access Journals (Sweden)

    Vasile Ostafe

    2007-08-01

    Full Text Available Within the recently launched the spectral-structure activity relationship (S-SARanalysis, the vectorial anionic-cationic model of a generic ionic liquid is proposed, alongwith the associated algebraic correlation factor in terms of the measured and predictedactivity norms. The reliability of the present scheme is tested by assessing the Hanschfactors, i.e. lipophylicity, polarizability and total energy, to predict the ecotoxicityendpoints of wide types of ionic liquids with ammonium, pyridinium, phosphonium,choline and imidazolium cations on the aquatic bacteria Vibrio fischeri. The results, whileconfirming the cationic dominant influence when only lipophylicity is considered,demonstrate that the anionic effect dominates all other more specific interactions. It wasalso proved that the S-SAR vectorial model predicts considerably higher activity for theionic liquids than for its anionic and cationic subsystems separately, in all consideredcases. Moreover, through applying the least norm-correlation path principle, the completetoxicological hierarchies are presented, unfolding the ecological rules of combined cationicand anionic influences in ionic liquid toxicity.

  9. Molecular dynamics simulations of ionic liquid-vapour interfaces: effect of cation symmetry on structure at the interface.

    Science.gov (United States)

    Sarangi, S S; Raju, S G; Balasubramanian, S

    2011-02-21

    The influence of alkyl chain symmetry of the imidazolium cation on the structure and properties of the ionic liquid-vapour interface has been addressed through molecular dynamics simulations. The anion chosen is bis(trifluoromethylsulfonyl)imide (NTf(2)). Profiles of number densities, orientation of cations, charge density, electrostatic potential, and surface tension have been obtained. At the interface, both cations and anions were present, and the alkyl chains of the former preferred to orient out into the vapour phase. A large fraction of cations preferred to be oriented with their ring-normal parallel to the surface and alkyl chains perpendicular to it. These orientational preferences are reduced in ionic liquids with symmetric cations. Although the charge densities at the interface were largely negative, an additional small positive charge density has been observed for systems with longer alkyl chains. The electrostatic potential difference developed between the liquid and the vapour phases were positive and decreased with increasing length of the alkyl group. The calculated surface tension of the liquids also decreased with increasing alkyl chain length, in agreement with experiment. The surface tension of an ionic liquid with symmetric cation was marginally higher than that of one with an asymmetric, isomeric cation.

  10. Recovery of Metallic Values from Brass Waste Using Brønsted Acidic Ionic Liquid as Leachate

    Science.gov (United States)

    Kilicarslan, Ayfer; Saridede, Muhlis Nezihi

    2015-11-01

    The waste formed during industrial brass manufacturing is rich in copper and zinc metals. Therefore, treatment of this waste is a necessity from economic and environmental aspects. This study presents a process for recovery of zinc and copper through Brønsted ionic liquid (1-butyl-3-methyl-imidazolium hydrogen sulfate; [Bmim]HSO4), as leachate. It was found that all zinc content could be dissolved from the waste under two optimum conditions: (1) in ionic liquid (IL) concentration of 70% (v/v) at 60°C in 30 min or (2) in IL concentration of 50% (v/v) at 100°C in 60 min. On the other hand, ionic liquid leaching gave poor copper solubility under the conditions of the study. Zinc dissolution in the range 5-75 min by [Bmim]HSO4 can be explained with the shrinking core model controlled by diffusion through a product layer, and the apparent activation energy was calculated as 4.36 kJ/mol. The leach liquor was treated to obtain metallic zinc by the electrowinning method without a purification step. Scanning electron microscopy/energy dispersive x-ray spectroscopy (SEM/EDX) investigations showed that the layer of metallic zinc was plated successfully on the cathode.

  11. Protein/ionic liquid/glassy carbon sensors following analyte focusing by ionic liquid micelle collapse for simultaneous determination of water soluble vitamins in plasma matrices.

    Science.gov (United States)

    Abd El-Hady, D; Albishri, H M

    2015-07-01

    Two novel sensors based on human serum albumin (HSA)-ionic liquid (IL) and bovine serum albumin (BSA)-ionic liquid (IL) composites modified glassy carbon electrode (GCE) were produced for simultaneous determination of water soluble vitamins B2, B6 and C in human plasma following analytes focusing by IL micelles collapse (AFILMC). For selective and efficient extraction, vitamins were dissolved in 3.0molL(-1) micellar solution of 1-octyl-3-methyl imidazolium bromide IL. The extracted vitamins were hydrodynamically injected by 25mbar for 20s into a running buffer of 12.5mmolL(-1) phosphate at pH 6.0 followed by electrochemical detection (ECD) on protein/1-octyl-3-methyl imidazolium hexafluorophosphate IL/GC sensors. The chemical stability of proposed sensors was achieved up to 7 days without any decomposition of PF6-based IL/protein and adsorption of interfering ions. In the current work, the sensitivity enhancement factor (SEF) up to 5000-fold was achieved using the AFILMC/ECD setup compared to conventional CE/UV. Under optimal conditions, linear calibration graphs were obtained from 0.5, 0.5 and 1.0 to 1500.0µgmL(-1) of vitamins B2, B6 and C, respectively. Detection limits of analytes were ranged from 180.0 to 520.0ngmL(-1). The proposed AFILMC/ECD setup was successfully applied to the assay of trace level quantification of vitamins in human plasma samples and also their binding constants with HSA and BSA were determined. The concurrent use of IL micelles for the proposed separation and detection processes exhibited some advantages, such as, a reduction of use toxic solvents, an efficient extraction and a direct injection of samples with a short-single run. Furthermore, IL micelles, having variable possibility of interactions, facilitated the successful achievements of AFILMC/ECD setup for the quantification of vitamins in plasma matrices. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. On the radiation stability of crown ethers in ionic liquids.

    Energy Technology Data Exchange (ETDEWEB)

    Shkrob, I.; Marin, T.; Dietz, M. (Chemical Sciences and Engineering Division); (Benedictine Univ.); (Univ. of Wisconsin at Milwaukee)

    2011-04-14

    Crown ethers (CEs) are macrocyclic ionophores used for the separation of strontium-90 from acidic nuclear waste streams. Room temperature ionic liquids (ILs) are presently being considered as replacements for traditional molecular solvents employed in such separations. It is desirable that the extraction efficacy obtained with such solvents should not deteriorate in the strong radiation fields generated by decaying radionuclides. This deterioration will depend on the extent of radiation damage to both the IL solvent and the CE solute. While radiation damage to ILs has been extensively studied, the issue of the radiation stability of crown ethers, particularly in an IL matrix, has not been adequately addressed. With this in mind, we have employed electron paramagnetic resonance (EPR) spectroscopy to study the formation of CE-related radicals in the radiolysis of selected CEs in ILs incorporating aromatic (imidazolium and pyridinium) cations. The crown ethers have been found to yield primarily hydrogen loss radicals, H atoms, and the formyl radical. In the low-dose regime, the relative yield of these radicals increases linearly with the mole fraction of the solute, suggesting negligible transfer of the excitation energy from the solvent to the solute; that is, the solvent has a 'radioprotective' effect. The damage to the CE in the loading region of practical interest is relatively low. Under such conditions, the main chemical pathway leading to decreased extraction performance is protonation of the macrocycle. At high radiation doses, sufficient to increase the acidity of the IL solvent significantly, such proton complexes compete with the solvent cations as electron traps. In this regime, the CEs will rapidly degrade as the result of H abstraction from the CE ring by the released H atoms. Thus, the radiation dose to which a CE/IL system is exposed must be maintained at a level sufficiently low to avoid this regime.

  13. NMR and Raman spectroscopy monitoring of proton/deuteron exchange in aqueous solutions of ionic liquids forming hydrogen bond: a role of anions, self-aggregation, and mesophase formation.

    Science.gov (United States)

    Klimavicius, Vytautas; Gdaniec, Zofia; Kausteklis, Jonas; Aleksa, Valdemaras; Aidas, Kestutis; Balevicius, Vytautas

    2013-09-05

    The H/D exchange process in the imidazolium-based room temperature ionic liquids (RTILs) 1-decyl-3-methyl-imidazolium bromide- and chloride ([C10mim][Br] and [C10mim][Cl]) in D2O solutions of various concentrations was studied applying (1)H, (13)C NMR, and Raman spectroscopy. The time dependencies of integral intensities in NMR spectra indicate that the H/D exchange in [C10mim][Br] at very high dilution (10(-4) mole fraction of RTIL) runs only slightly faster than in [C10mim][Cl]. The kinetics of this process drastically changes above critical aggregation concentration (CAC). The time required to reach the apparent reaction saturation regime in the solutions of 0.01 mole fraction of RTIL was less 10 h for [C10mim][Br], whereas no such features were seen for [C10mim][Cl] even tens of days after the sample was prepared. The H/D exchange was not observed in the liquid crystalline gel mesophase. The role of anions, self-aggregation (micellization), and mesophase formation has been discussed. Crucial influence of Br(-) and Cl(-) anions on the H/D exchange rates above CAC could be related to the short-range ordering and molecular microdynamics, in particular that of water molecules. The concept of the conformational changes coupled with the H/D exchange in imidazolium-based ionic liquids with longer hydrocarbon chains can be rejected in the light of (13)C NMR experiment. The revealed changes in (13)C NMR spectra are caused by the secondary ((13)C) isotope effects not being the signal shifts due to the conformational trans-gauche transition.

  14. Replica-exchange molecular dynamics simulations of cellulose solvated in water and in the ionic liquid 1-butyl-3-methylimidazolium chloride.

    Science.gov (United States)

    Mostofian, Barmak; Cheng, Xiaolin; Smith, Jeremy C

    2014-09-25

    Ionic liquids have become a popular solvent for cellulose pretreatment in biorefineries due to their efficiency in dissolution and their reusability. Understanding the interactions between cations, anions, and cellulose is key to the development of better solvents and the improvement of pretreatment conditions. While previous studies described the interactions between ionic liquids and cellulose fibers, shedding light on the initial stages of the cellulose dissolution process, we study the end state of that process by exploring the structure and dynamics of a single cellulose decamer solvated in 1-butyl-3-methyl-imidazolium chloride (BmimCl) and in water using replica-exchange molecular dynamics. In both solvents, global structural features of the cellulose chain are similar. However, analyses of local structural properties show that cellulose explores greater conformational variability in the ionic liquid than in water. For instance, in BmimCl the cellulose intramolecular hydrogen bond O3H'···O5 is disrupted more often resulting in greater flexibility of the solute. Our results indicate that the cellulose chain is more dynamic in BmimCl than in water, which may play a role in the favorable dissolution of cellulose in the ionic liquid. Calculation of the configurational entropy of the cellulose decamer confirms its higher conformational flexibility in BmimCl than in water at elevated temperatures.

  15. Determination and modelling of osmotic coefficients and vapour pressures of binary systems 1- and 2-propanol with C{sub n}MimNTf{sub 2} ionic liquids (n = 2, 3, and 4) at T = 323.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Calvar, Noelia [LSRE - Laboratory of Separation and Reaction Engineering, Associate Laboratory, LSRE/LCM, Department of Chemical Engineering, Faculty of Engineering, Rua Dr. Roberto Frias s/n, Porto 4200-465 (Portugal); Gomez, Elena; Dominguez, Angeles [Advanced Separation Processes Group, Department of Chemical Engineering, University of Vigo, 36310 Vigo (Spain); Macedo, Eugenia A., E-mail: eamacedo@fe.up.pt [LSRE - Laboratory of Separation and Reaction Engineering, Associate Laboratory, LSRE/LCM, Department of Chemical Engineering, Faculty of Engineering, Rua Dr. Roberto Frias s/n, Porto 4200-465 (Portugal)

    2011-08-15

    Highlights: > Osmotic coefficients of 1- and 2-propanol with C{sub n}MimNTf{sub 2} (n = 2, 3, and 4) are determined. > Experimental data were correlated with extended Pitzer model of Archer and MNRTL. > Mean molal activity coefficients and excess Gibbs free energies were calculated. > Effect of the anion is studied comparing these results with literature. - Abstract: The osmotic and activity coefficients and vapour pressures of binary mixtures containing 1-propanol, or 2-propanol and imidazolium-based ionic liquids with bis(trifluoromethylsulfonyl)imide as anion (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, C{sub 2}MimNTf{sub 2}, 1-methyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide, C{sub 3}MimNTf{sub 2}, and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, C{sub 4}MimNTf{sub 2}) were determined at T = 323.15 K using the vapour pressure osmometry technique. The experimental osmotic coefficients were correlated using the extended Pitzer model modified by Archer and the MNRTL model, obtaining standard deviations lower than 0.033 and 0.064, respectively. The mean molal activity coefficients and the excess Gibbs free energy for the mixtures studied were calculated from the parameters of the extended Pitzer model modified by Archer. Besides the effect of the alkyl-chain of the cation, the effect of the anion can be assessed comparing the experimental results with those previously obtained for imidazolium ionic liquids with sulphate anions.

  16. Polystyrene-block-Poly(ionic liquid) Copolymers as Work Function Modifiers in Inverted Organic Photovoltaic Cells.

    Science.gov (United States)

    Park, Jong Baek; Isik, Mehmet; Park, Hea Jung; Jung, In Hwan; Mecerreyes, David; Hwang, Do-Hoon

    2018-02-07

    Interfacial layers play a critical role in building up the Ohmic contact between electrodes and functional layers in organic photovoltaic (OPV) solar cells. These layers are based on either inorganic oxides (ZnO and TiO 2 ) or water-soluble organic polymers such as poly[(9,9-dioctyl-2,7-fluorene)-alt-(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)] and polyethylenimine ethoxylated (PEIE). In this work, we have developed a series of novel poly(ionic liquid) nonconjugated block copolymers for improving the performance of inverted OPV cells by using them as work function modifiers of the indium tin oxide (ITO) cathode. Four nonconjugated polyelectrolytes (n-CPEs) based on polystyrene and imidazolium poly(ionic liquid) (PSImCl) were synthesized by reversible addition-fragmentation chain transfer polymerization. The ratio of hydrophobic/hydrophilic block copolymers was varied depending on the ratio of polystyrene to the PSImCl block. The ionic density, which controls the work function of the electrode by forming an interfacial dipole between the electrode and the block copolymers, was easily tuned by simply changing the PSImCl molar ratio. The inverted OPV device with the ITO/PS 29 -b-PSImCl 60 cathode achieved the best power conversion efficiency (PCE) of 7.55% among the synthesized block copolymers, exhibiting an even higher PCE than that of the reference OPV device with PEIE (7.30%). Furthermore, the surface properties of the block copolymers films were investigated by contact angle measurements to explore the influence of the controlled hydrophobic/hydrophilic characters on the device performances.

  17. C-H activation of imidazolium salts by Pt(0) at ambient temperature: synthesis of hydrido platinum bis(carbene) compounds.

    Science.gov (United States)

    Duin, Marcel A; Clement, Nicolas D; Cavell, Kingsley J; Elsevier, Cornelis J

    2003-02-07

    A zerovalent platinum(carbene) complex with two monoalkene ligands, which is able to activate C-H bonds of imidazolium salts at room temperature to yield isolable hydrido platinum(II) bis(carbene) compounds, has been synthesised for the first time.

  18. 'Janus-type' organopotassium chemistry observed in deprotonation of mesoionic imidazolium aminides and amino N-heterocyclic carbenes: coordination and organometallic polymers.

    Science.gov (United States)

    Danopoulos, Andreas A; Braunstein, Pierre

    2014-03-21

    The first direct observation of the tautomeric equilibrium between mesoionic imidazolium aminides (IA) and amino NHCs (AC) shows its dependence on the aminide substituent. A potassium (imidazol-2-ylidenyl)(anilide), an ion-pair with the 'free' anionic NHC, and potassium organometallic polymers, with the repeat unit exhibiting 'Janus-type' coordination, are reported.

  19. 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

  20. [Activity of new iminium compounds against bacteria and fungi. 28. Synthesis of 1-ethyl-, 1-n-dodecyl-2-phenyl-3-(n-alkylthiomethyl)- and 1-ethyl-, 1-n-dodecyl-2-phenyl-3-(n-alkoxymethyl)imidazolium chlorides].

    Science.gov (United States)

    Pernak, J; Krysiński, J; Skrzypczak, A

    1992-08-01

    The synthesis of quaternary imidazolium compounds was performed by reaction of 1-ethyl- or 1-n-dodecyl-2-phenylimidazole with chloromethyl-n-alkyl ether or chloromethyl-n-alkyl sulfid. The antibacterial properties of the compounds obtained were tested on 13 strains of bacteria and fungi. 1-Ethyl-2-phenyl-3-(n-decylthiomethyl)-, 1-ethyl-2-phenyl-3-(n-dodecylthiomethyl)imidazolium chloride and 1-n-dodecyl-2-phenyl-3-(n-butylthiomethyl)-, 1-n-dodecyl-2-phenyl-3-(n-hexylthiomethyl)imidazolium chloride indicated the best antibacterial activity.

  1. 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.

  2. Determination of hydrogen-bond-accepting and -donating abilities of ionic liquids with halogeno complex anions by means of 1H NMR spectroscopy.

    Science.gov (United States)

    Lungwitz, Ralf; Spange, Stefan

    2012-05-14

    Hydrogen-bond-accepting (HBA) and -donating (HBD) parameters of ionic liquids (ILs) with halogeno complex anions are determined by means of (1)H NMR spectroscopy. Thereby, the imidazolium cation serves both as part of the IL and as (1)H NMR probe. The HBA and HBD strength are calculated in terms of the empirical polarity parameters β and α according to the Kamlet-Taft equation. The study includes 1-butyl-3-methylimidazolium ILs with chloroaluminates of various mole fractions from 0 to 0.67 of AlCl(3), anions of the general chemical formula MtX(n)(-) (Mt=metal, X=halide) as well as tri- and pentaiodide. The (1)H NMR chemical shift of the hydrogen atom in the two position of the imidazolium cation is a function of the HBA ability of the corresponding anion. For the chloroaluminates the HBA ability decreases and the HBD ability increases with increasing mole fraction of the Lewis acid. In general, the HBA strength of the studied ILs increases in the following order: MoCl(6)(-) < Al(2)Cl(7)(-) < AlCl(4)(-) < WCl(7)(-) < I(5)(-) < SnCl(5)(-) < I(3)(-) < SbCl(6)(-) < TiCl(5)(-) < BBr(4)(-) < SnCl(3)(-). The corresponding HBD ability shows a reverse trend. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Coupling of OECD standardized test and immunomarkers to select the most environmentally benign ionic liquids option—Towards an innovative “safety by design” approach

    Energy Technology Data Exchange (ETDEWEB)

    Bado-Nilles, Anne, E-mail: Anne.Bado-Nilles@ineris.fr [Institut National de l’Environnement Industriel et des Risques (INERIS), UMR-I 02 SEBIO, B.P. 2, 60550 Verneuil-en-Halatte (France); Université de Reims Champagne-Ardenne, UMR-I 02 SEBIO, Campus Moulin de la Housse, B.P. 1039, 51687 REIMS cedex (France); Diallo, Alpha-Oumar, E-mail: Alpha-Oumar.Diallo@ineris.fr [INERIS, Pôle Substances et Procédés, B.P. 2, 60550 Verneuil-en-Halatte (France); Marlair, Guy, E-mail: Guy.Marlair@ineris.fr [INERIS, Pôle Substances et Procédés, B.P. 2, 60550 Verneuil-en-Halatte (France); Pandard, Pascal, E-mail: Pascal.Pandard@ineris.fr [INERIS, Unité Expertise et essais en écotoxicologie, B.P. 2, 60550 Verneuil-en-Halatte (France); Chabot, Laure, E-mail: Laure.Chabot@ineris.fr [INERIS, Unité Expertise et essais en écotoxicologie, B.P. 2, 60550 Verneuil-en-Halatte (France); Geffard, Alain, E-mail: Alain.Geffard@univ-reims.fr [Université de Reims Champagne-Ardenne, UMR-I 02 SEBIO, Campus Moulin de la Housse, B.P. 1039, 51687 REIMS cedex (France); Len, Christophe, E-mail: Christophe.Len@utc.fr [Université Technologique de Compiègne/ESCOM, EA 4297, Transformations Intégrées de la Matière Renouvelable, Centre de Recherches de Royallieu, B.P. 20529, F-60205 Compiègne Cedex (France); Department of Chemistry, University of Hull, Hull HU6 7RX (United Kingdom); and others

    2015-02-11

    Highlights: • Development of innovative method for more in depth assessment of ecotoxicity of ILs. • Lower toxicity of imidazolium compared to phosphonium-based ILs. • ILs families possessed dissimilar effect on immune system of fish. • More impact of cation than anion in toxicological and biological activities. - Abstract: This paper proposed a potential industrial accompaniment to reduce ionic liquid harmfulness by a novel combination of OECD Daphnia magna standardized test and fish immunomarkers. The combination of these two tests allowed multicriteria examination of ILs impacts in different organisms and trophic levels. The work provided new data for legislation and opened a door towards an integrative environmental evaluation due to direct implications of immune system in fish and ecosystem health. Whatever the species, each IL tested induced deleterious effects suggesting that toxic impact was especially due to IL lipophilicity properties. Nevertheless, cation moieties of ILs seemed to draw overall toxicity of ILs to significant extent as supported by lower cell mortality shown with imidazolium-based ILs compared to phosphonium-based ILs. However, the anions moieties have some additional effect, as revealed by quite dissimilar toxicity within same IL family. Concerning the more integrative biomarkers, the cationic-based ILs tested possessed also dissimilar effect on immune system of fish, especially on leucocyte distribution, lysosomal membrane integrity and phagocytosis activity. These results confirm that ILs toxicity could be influenced by design and that chemical engineering processes can integrate ecological footprint reduction strategies for successful IL utilization in the future.

  4. 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.

  5. Ionic thermoelectric gating organic transistors

    Science.gov (United States)

    Zhao, Dan; Fabiano, Simone; Berggren, Magnus; Crispin, Xavier

    2017-01-01

    Temperature is one of the most important environmental stimuli to record and amplify. While traditional thermoelectric materials are attractive for temperature/heat flow sensing applications, their sensitivity is limited by their low Seebeck coefficient (∼100 μV K−1). Here we take advantage of the large ionic thermoelectric Seebeck coefficient found in polymer electrolytes (∼10,000 μV K−1) to introduce the concept of ionic thermoelectric gating a low-voltage organic transistor. The temperature sensing amplification of such ionic thermoelectric-gated devices is thousands of times superior to that of a single thermoelectric leg in traditional thermopiles. This suggests that ionic thermoelectric sensors offer a way to go beyond the limitations of traditional thermopiles and pyroelectric detectors. These findings pave the way for new infrared-gated electronic circuits with potential applications in photonics, thermography and electronic-skins. PMID:28139738

  6. 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.

  7. Ionic emission from Taylor cones

    Science.gov (United States)

    Castro Reina, Sergio

    Electrified Taylor cones have been seen as an efficient way to generate thrust for space propulsion. Especially the pure ionic regime (PIR) combines a very high specific impulse (thrust per unit mass) and efficiency, which is very important to reduce fuel transportation costs. The PIR has been primarily based on electrosprays of liquid metals [Swatik and Hendricks 1968, Swatik 1969]. However, emissions dominated by or containing exclusively ions have also been observed from nonmetallic purely ionic substances, initially sulfuric acid [Perel et al. 1969], and more recently room temperature molten salts referred to as ionic liquids (ILs) [Romero-Sanz et al. 2003]. The recent use of the liquid metal ion source (LMIS) with ILs, becoming this "new" source to be known as ionic liquid ion source (ILIS) [Lozano and Martinez-Sanchez 2005], has shown important differences on the emission from Taylor cones with the traditional hollow capillary. This new source seems to be more flexible than the capillary [Paulo, Sergio, carlos], although its low emission level (low thrust) is an important drawback from the space propulsion point of view. Throughout the thesis I have studied some aspects of the ionic emission from ionic liquid Taylor cones and the influence of the properties of the liquids and the characteristic of source on the emission. I have unraveled the reason why ILIS emits such low currents (˜200 nA) and found a way to solve this problem increasing the current up to capillary levels (˜1000 nA) [Castro and Fernandez de la Mora 2009]. I have also tried to reduce ion evaporation while reducing the emitted droplet size in order to increase the thrust generated while keeping the efficiency relatively high and I have measured the energy of evaporation of several cations composing ionic liquids, mandatory step to understand ionic evaporation.

  8. 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.

  9. Study on the growth and photosynthetic characteristics of wheat seedlings under [C₄mim][OAc] (1-butyl-3-methyl-imidazolium acetate) with Cd²⁺ stress.

    Science.gov (United States)

    Chen, Zhonglin; Feng, Yingying; Wang, Yan; Li, Yue; Liu, Qiang; Xu, Sunan; Guan, Wei

    2015-05-01

    In this paper, the joint effect of 0.5 mmol·L(-1) Cd(2+) and various concentrations (50-400 mg·L(-1)) of the ionic liquid 1-butyl-3-methyl-imidazolium acetate ([C4min][OAc]) on the growth and photosynthetic performance of wheat seedlings in hydroponic culture was investigated. Seedlings grown in presence of Cd(2+) and [C4min][OAc] showed significant (p < 0.05) improvement in growth (shoot and root lengths and dry weights) and photosynthetic performance (photosynthetic rate, stomatal conductance, transpiration rate, and chlorophyll a but not chlorophyll b) compared to seedlings grown in the presence of Cd(2+) but without [C4min][OAc]. However, this only happened under the lower range of [C4min][OAc] concentrations (50-200 mg·L(-1)). In addition, significant reduction in the level of Cd(2+) was also observed in the leaf tissue of wheat seedlings grown in the presence of 0.5 mmol·L(-1) Cd(2+) and 100 mg·L(-1) [C4min][OAc]. Overall, Cd(2+) exerted a stronger inhibition than [C4min][OAc] on the growth and photosynthetic performance of wheat seedlings. However, when both Cd(2+) and [C4min][OAc] were present in the culture, the toxicity of Cd(2+) could be mitigated by lower concentrations of [C4mim][OAc]. This phenomenon could be due to [C4mim][OAc] forming metal complexes with Cd(2+), thus reducing the toxicity of Cd(2+).

  10. Ionic Liquid-Modified Thermosets and Their Nanocomposites: Dispersion, Exfoliation, Degradation, and Cure

    Science.gov (United States)

    Throckmorton, James A.

    This dissertation explores the application of a room temperature ionic liquid (RTIL) to problems in the chemistry, processing, and modification of thermosetting polymers. In particular, the solution properties and reaction chemistry of 1-ethyl-3-methyl imidazolium dicyanamide (EMIM-DCN) are applied to problems of nanoparticle dispersion and processing, graphite exfoliation, cyanate ester (CE) cure, and the environmental degradation of CEs. Nanoparticle Dispersion: Nanocomposite processing can be simplified by using the same compound as both a nanoparticle solvent and an initiator for polymerization. This dual-function molecule can be designed both for solvent potential and reaction chemistry. EMIM-DCN, previously shown by our lab to act as an epoxy initiator, is used in the synthesis of silica and acid expanded graphite composites. These composites are then characterized for particle dispersion and physical properties. Individual particle dispersion of silica nanocomposites is shown, and silica nanocomposites at low loading show individual particle dispersion and improved modulus and fracture toughness. GNP nanocomposites show a 70% increase in modulus along with a 10-order of magnitude increase in electrical conductivity at 6.5 vol%, and an electrical percolation threshold of 1.7 vol%. Direct Graphite Exfoliation By Laminar Shear: This work presents a laminar-shear alternative to chemical processing and chaotic flow-fields for the direct exfoliation of graphite and the single-pot preparation of nanocomposites. Additionally, we develop the theory of laminar flow through a 3-roll mill, and apply that theory to the latest developments in the theory of graphite interlayer shear. The resulting nanocomposite shows low electrical percolation (0.5 vol%) and low thickness (1-3 layer) graphite/graphene flakes. Additionally, the effect of processing conditions by rheometry and comparison with solvent-free conditions reveal the interactions between processing and matrix

  11. Ionic liquid-capped graphene quantum dots as label-free fluorescent probe for direct detection of ferricyanide.

    Science.gov (United States)

    Sun, Xue; Qian, Yuting; Jiao, Yajie; Liu, Jiyang; Xi, Fengna; Dong, Xiaoping

    2017-04-01

    Despite complex molecular and atomic doping, efficient post-functionalization strategies for graphene quantum dots (GQDs) are of key importance to control the physicochemical properties and broaden the practical applications. With ionic liquid as specific modification agents, herein, the preparation of ionic liquid-capped GQDs (IL-GQDs) and its application as label-free fluorescent probe for direct detection of anion were reported. Hydroxyl-functionalized GQDs that could be easily gram-scale synthesized and possessed single-crystalline were chosen as the model GQDs. Also, the most commonly used ionic liquids, water-soluble 1-butyl-3-methyl imidazolium tetrafluoroborate (BMIMBF 4 ) was chosen as the model IL. Under the ultrasonic treatment, BMIMBF 4 easily composited with GQDs to form IL-GQDs. The synthesized IL-GQDs were characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and fluorescence (FL) spectrum. After successful combination with IL, the excitation-independent photoluminescence behavior of GQDs presented almost no change, whereas, the anion responsiveness of IL-GQDs drastically improved, which afforded the IL-GQDs a sensitive response to Fe(CN) 6 3- . Based on the strong fluorescence quench, a facile and sensitive detection of Fe(CN) 6 3- was achieved. A wide linear range of 1.0×10 -7 to 2.5×10 -3 moll -1 with a low detection limit of 40 nmol l -1 was obtained. As the composition and properties of IL and GQDs could be easily tuned by varying the structure, ionic liquids-capped GQDs might present promising potential for their applications in sensing and catalysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. [Actions of new iminium compounds on bacteria and fungi. 27. Synthesis of 1-n-decyl-2-phenyl-3-(n-alkylthiomethyl)- and 1-n-decyl-2-phenyl-3-(n-alkoxymethyl)imidazolium chlorides].

    Science.gov (United States)

    Pernak, J; Skrzypczak, A; Michalak, L; Krysinski, J

    1992-08-01

    The imidazolium compounds 1-3 were prepared by quaternization of 1-decyl-2-phenylimidazole with the pertinent chloromethyl-n-alkyl ethers. 1-3 were tested for their antibacterial and antimycotic efficacies.

  13. Ionic Conductivity of Polyelectrolyte Hydrogels.

    Science.gov (United States)

    Lee, Chen-Jung; Wu, Haiyan; Hu, Yang; Young, Megan; Wang, Huifeng; Lynch, Dylan; Xu, Fujian; Cong, Hongbo; Cheng, Gang

    2018-01-31

    Polyelectrolytes have many important functions in both living organisms and man-made applications. One key property of polyelectrolytes is the ionic conductivity due to their porous networks that allow the transport of water and small molecular solutes. Among polyelectrolytes, zwitterionic polymers have attracted huge attention for applications that involve ion transport in a polyelectrolyte matrix; however, it is still unclear how the functional groups of zwitterionic polymer side chains affect their ion transport and swelling properties. In this study, zwitterionic poly(carboxybetaine acrylamide), poly(2-methacryloyloxyethyl phosphorylcholine), and poly(sulfobetaine methacrylate) hydrogels were synthesized and their ionic conductivity was studied and compared to cationic, anionic, and nonionic hydrogels. The change of the ionic conductivity of zwitterionic and nonionic hydrogels in different saline solutions was investigated in detail. Zwitterionic hydrogels showed much higher ionic conductivity than that of the widely used nonionic poly(ethylene glycol) methyl ether methacrylate hydrogel in all tested solutions. For both cationic and anionic hydrogels, the presence of mobile counterions led to high ionic conductivity in low salt solutions; however, the ionic conductivity of zwitterionic hydrogels surpassed that of cationic and ionic hydrogels in high salt solutions. Cationic and anionic hydrogels showed much higher water content than that of zwitterionic hydrogels in deionized water; however, the cationic hydrogels shrank significantly with increasing saline concentration. This work provides insight into the effects of polyelectrolyte side chains on ion transport. This can guide us in choosing better polyelectrolytes for a broad spectrum of applications, including bioelectronics, neural implants, battery, and so on.

  14. Quasi Solid-State Dye-Sensitized Solar Cell Incorporating Highly Conducting Polythiophene-Coated Carbon Nanotube Composites in Ionic Liquid

    Directory of Open Access Journals (Sweden)

    Mohammad Rezaul Karim

    2011-01-01

    Full Text Available Conducting polythiophene (PTh composites with the host filler multiwalled carbon nanotube (MWNT have been used, for the first time, in the dye-sensitized solar cells (DSCs. A quasi solid-state DSCs with the hybrid MWNT-PTh composites, an ionic liquid of 1-methyl-3-propyl imidazolium iodide (PMII, was placed between the dye-sensitized porous TiO2 and the Pt counter electrode without adding iodine and higher cell efficiency (4.76% was achieved, as compared to that containing bare PMII (0.29%. The MWNT-PTh nanoparticles are exploited as the extended electron transfer materials and serve simultaneously as catalyst for the electrochemical reduction of I−3.

  15. 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)

  16. Effect of telechelic ionic groups on the dispersion of organically modified clays in bisphenol A polycarbonate nanocomposites by in-situ polymerization using activated carbonates

    Directory of Open Access Journals (Sweden)

    M. Colonna

    2017-05-01

    Full Text Available Nanocomposites of bisphenol A polycarbonate with organically modified clays have been prepared for the first time by in-situ polymerization using bis(methyl salicyl carbonate as activated carbonate. The use of the activated carbonate permits to conduct the polymerization reaction at lower temperature and with shorter polymerization time with respect to those necessary for traditional melt methods that uses diphenyl carbonate, affording a nanocomposite with improved color. Moreover, an imidazolium salt with two long alkyl chains has been used to modify the montmorillonite, providing an organically modified clay with high thermal stability and wide d-spacing. The addition of ionic groups at the end of the polymer chain increases the interaction between the clay surface and the polymer producing a better dispersion of the clay. The presence of the clay increases the thermal stability of the polymer.

  17. Synthesis and Biological Evaluation of New Imidazolium and Piperazinium Salts of Pyropheophorbide-a for Photodynamic Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Young Key Shim

    2008-08-01

    Full Text Available We have designed imidazolium and piperazinium salts of pyropheophorbide-a in order to develop effective photosensitizers which have good solubility in polar and non polar media and to reveal the possible influences of the piperazine and imidazole moieties on the biological activities of pyropheophorbide-a. The phototoxicity of those pyropheophorbide-a salts against A549 cells was studied in vitro and compared with that of pyropheophorbide-a. The result showed that complexing piperazine and imidazole into pyropheophorbide-a decreases its dark toxicity without greatly decreasing phototoxicity and, enhances its phototoxicity without greatly increasing dark toxicity, respectively. This work not only describes novel amphiphilic salt complexes of pyropheophobide-a which retain the biological activities of the parent compound pyropheophorbide-a and could be effective candidate for PDT, but also reveals the possibility of developing effective photosensitizers by complexing imidazole and piperazine into other hydrophobic photosensitizers.

  18. 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.)

  19. Effect of Anion and Alkyl Side Chain on Structural and Dynamic Features of Ester Functionalized Ionic Liquids: Confirming Nanoscale Organization.

    Science.gov (United States)

    Fakhraee, Mostafa; Gholami, Mohammad Reza

    2016-11-10

    The effects of ester addition on structural and dynamic properties of biodegradable ILs composed of the 1-(alkoxycarbonyl)-3-alkylimidazolium cation ([C 1 COOC n C 1 im] + , n = 1, 2, 4) coupled with [Br] - , [NO 3 ] - , [BF 4 ] - , [PF 6 ] - , [TfO] - , and [Tf 2 N] - are explored using the molecular dynamics (MD) simulations and quantum theory of atoms in molecules (QTAIM) at 400 K. Formation of the intramolecular H bonds between O atoms of the ester group and H atoms of the imidazolium ring as well as the nearest H atom of the alkyl chain to the ester group are disclosed from reduced density gradient (RDG) results. Nanoscale organization that leads to aggregation of the alkyl chain into the uncharged domains and formation of different morphologies can be clearly found by the results of site-site static partial structure factors of cations. Despite the fact that H atoms of the imidazolium ring are more acidic than the nearest H atoms of the alkyl side chain to the ester group, the cation-cation spatial distribution functions (SDFs) and the velocity SDFs demonstrate a reverse trend. This corresponds to the long-range organization of cations and nanoscale arrangement. Transport properties were calculated using the Green-Kubo and Einstein relations. Cations totally diffuse faster than anions and their discrepancies gradually vanish with elongation of the alkyl side chain. The translational motion of the terminal carbon atoms of the ester-functionalized cations decrease when the alkyl group is elongated, whereas the reverse trend is reported for common imidazolium-based ILs. The dynamic heterogeneity of selected ILs is comprehensively investigated by the computing vibrational density of states, van Hove function, and non-Gaussian parameter. Non-Gaussian parameters are finite over the entire time scale for ILs composed of bulkier cations and diverge from zero, verifying the long-lived cage effect. Nanoscale ordering is believed to be responsible for these observations

  20. Theoretical Study on the Solvation of C60 Fullerene by Ionic Liquids II: DFT Analysis of the Interaction Mechanism.

    Science.gov (United States)

    García, Gregorio; Atilhan, Mert; Aparicio, Santiago

    2015-08-20

    As a continuation of our previous work (J. Phys. Chem. B, 2014, 118, 11330) on the solvation of C60 by ionic liquids (ILs) using Molecular Dynamic simulations, this paper reports a systematic density functional theory (DFT) analysis on the interaction mechanism between C60 and 24 different ionic liquids (belonging to the imidazolium, piperazinium, and cholinium groups). Properties such as binding energies, charge distributions, intermolecular interactions, or electronic structure were analyzed as a function of the selected ILs. The stronger IL-C60 interactions would be related with π-π stacking between the C60 surface and anions such as salycilate ([SA]). Likewise, the electronic structure analysis pointed to a well-defined relationship between the energetics of IL-C60 systems and IL features. Therefore, ILs with deep HOMO energies as well as weak interaction between both ions would be a priori good candidates for C60 solvation. Although only short-range interactions are studied in the framework of DFT, this work provides useful information for the rational design of ILs that could exhibit suitable features as C60 solvents.

  1. Improving the Conductivity of Sulfonated Polyimides as Proton Exchange Membranes by Doping of a Protic Ionic Liquid

    Directory of Open Access Journals (Sweden)

    Bor-Kuan Chen

    2014-10-01

    Full Text Available Proton exchange membranes (PEMs are a key component of a proton exchange membrane fuel cell. Sulfonated polyimides (SPIs were doped by protic ionic liquid (PIL to prepare composite PEMs with substantially improved conductivity. SPIs were synthesized from diamine, 2,2-bis[4-(4-amino-phenoxyphenyl]propane (BAPP, sulfonated diamine, 4,4'-diamino diphenyl ether-2,2'-disulfonic acid (ODADS and aromatic anhydride. BAPP improved the mechanical and thermal properties of SPIs, while ODADS enhanced conductivity. A PIL, 1-vinylimidazolium trifluoromethane-sulfonate ([VIm][OTf], was utilized. [VIm][OTf] offered better conductivity, which can be attributed to its vinyl chemical structure attached to an imidazolium ring that contributed to ionomer-PIL interactions. We prepared sulfonated polyimide/ionic liquid (SPI/IL composite PEMs using 50 wt% [VIm][OTf] with a conductivity of 7.17 mS/cm at 100 °C, and in an anhydrous condition, 3,3',4,4'-diphenyl sulfone tetracarboxylic dianhydride (DSDA was used in the synthesis of SPIs, leading to several hundred-times improvement in conductivity compared to pristine SPIs.

  2. Isolation of natural red colorants from fermented broth using ionic liquid-based aqueous two-phase systems.

    Science.gov (United States)

    Ventura, Sónia P M; Santos-Ebinuma, Valéria C; Pereira, Jorge F B; Teixeira, Maria F S; Pessoa, Adalberto; Coutinho, João A P

    2013-05-01

    There is a growing demand for natural colorants. This is prompting the search for new alternative and "benign" separation systems allowing higher recoveries, extraction yields, and selectivities. This work investigates the use of aqueous two-phase systems (ATPS) based on ionic liquids as extraction processes for the recovery of red colorants from the fermented broth of Penicillium purpurogenum DPUA 1275. Several ATPS based on quaternary ammonium and imidazolium were studied in this work aiming at separating the red colorants produced from the remaining colorants and contaminant proteins present in the fermented broth. The results suggest that the red colorants can be isolated by an appropriate manipulation of some of the process conditions, such as the use of quaternary ammonium with short alkyl chains, alkaline media, and short tie-line lengths (extraction point systems with lower concentrations of ionic liquid). These conditions allow large partition coefficients for the red colorants (K red = 24.4 ± 2.3), high protein removal (60.7 ± 2.8 %) and selectivity parameters (S red/prot = 10.05).

  3. Special Effect of Ionic Liquids on the Extraction of Flavonoid Glycosides from Chrysanthemum morifolium Ramat by Microwave Assistance

    Directory of Open Access Journals (Sweden)

    Ying Zhou

    2015-04-01

    Full Text Available A microwave-assisted extraction approach based on ionic liquids of different chain lengths was successfully applied to the extraction of ten flavonoid glycosides from the flowering heads of Chrysanthemum morifolium Ramat. The pretreated sample was quantified by HPLC-ESI-MSn. The main components were identified as flavonoid glycosides, including three luteolin glycosides, three apigenin glycosides, three kaempferide glycosides, and one acacetin glycoside according to the characteristics of the corresponding CID mass spectrometric patterns. Eight ionic liquids from the imidazolium family with different chain lengths, namely, 1-alkyl-3-methylimidazolium bromide, [Cnmim]Br, (n = 2–16 were studied as extraction medium in water. Results indicated that alkyl chain length had an irregular impact on the extraction efficiency. Moreover, the best extraction efficiency was achieved by 1-dodecyl-3-methylimidazolium bromide aqueous solution ([C12mim]Br. Besides the alkyl chain length of the cations, other factors influencing extraction efficiency were systematically investigated, including concentration of the IL solutions, extraction time, matrix-to-solvent ratio and irradiation power.

  4. Direct electrochemistry and electrocatalysis of horseradish peroxidase with hyaluronic acid-ionic liquid-cadmium sulfide nanorod composite material

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Zhihong [Institute of Nano-Science and Technology Center, Huazhong Normal University, Wuhan 430079 (China); Li Xia; Wang Yan [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Zeng Yan [Institute of Nano-Science and Technology Center, Huazhong Normal University, Wuhan 430079 (China); Sun Wei, E-mail: sunwei@qust.edu.cn [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Huang Xintang [Institute of Nano-Science and Technology Center, Huazhong Normal University, Wuhan 430079 (China)

    2010-06-18

    A new composite material consisted of hyaluronic acid (HA), ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF{sub 4}) and cadmium sulfide (CdS) nanorod was fabricated and used for the immobilization of horseradish peroxidase (HRP) on the surface of a carbon ionic liquid electrode (CILE), which was prepared with 1-ethyl-3-methyl-imidazolium ethylsulphate ([EMIM]EtOSO{sub 3}) as modifier. Spectroscopic results indicated that HRP remained its native structure in the composite film. Based on the synergistic effect of the materials used, an obvious promotion to the direct electron transfer efficient between HRP and CILE was achieved with a pair of well-defined redox peaks appeared in 0.1 mol L{sup -1} phosphate buffer solution, indicating the realization of the direct electrochemistry of HRP. The immobilized HRP showed good electrocatalytic activity towards the reduction of trichloroacetic acid and H{sub 2}O{sub 2} with the electrochemical parameters calculated. Based on the fabricated electrode, a new third-generation electrochemical biosensor was constructed with good stability and reproducibility.

  5. 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.

  6. Special Effect of Ionic Liquids on the Extraction of Flavonoid Glycosides from Chrysanthemum morifolium Ramat by Microwave Assistance.

    Science.gov (United States)

    Zhou, Ying; Wu, Datong; Cai, Pengfei; Cheng, Guifang; Huang, Chaobiao; Pan, Yuanjiang

    2015-04-28

    A microwave-assisted extraction approach based on ionic liquids of different chain lengths was successfully applied to the extraction of ten flavonoid glycosides from the flowering heads of Chrysanthemum morifolium Ramat. The pretreated sample was quantified by HPLC-ESI-MSn. The main components were identified as flavonoid glycosides, including three luteolin glycosides, three apigenin glycosides, three kaempferide glycosides, and one acacetin glycoside according to the characteristics of the corresponding CID mass spectrometric patterns. Eight ionic liquids from the imidazolium family with different chain lengths, namely, 1-alkyl-3-methylimidazolium bromide, [Cnmim]Br, (n=2-16) were studied as extraction medium in water. Results indicated that alkyl chain length had an irregular impact on the extraction efficiency. Moreover, the best extraction efficiency was achieved by 1-dodecyl-3-methylimidazolium bromide aqueous solution ([C12mim]Br). Besides the alkyl chain length of the cations, other factors influencing extraction efficiency were systematically investigated, including concentration of the IL solutions, extraction time, matrix-to-solvent ratio and irradiation power.

  7. Hydrophobic Poly(ionic liquid for Highly Effective Separation of Methyl Blue and Chromium Ions from Water

    Directory of Open Access Journals (Sweden)

    Jie Kong

    2013-10-01

    Full Text Available The hydrophobic poly(ionic liquid of poly(3-ethyl-1-vinylimidazolium bis(trifluoromethanesulfonylimide (PVI-TFSI containing imidazolium cations and bis(trifluoromethanesulfonylimide anions was synthesized for the separation of methyl blue and chromium ions [Cr(VI] from water. The adsorption of methyl blue and Cr(VI in PVI-TSFI/water system reached equilibrium stage within 60 min and 12 h, and the maximum adsorbed percentage for methyl blue and Cr(VI was 97.6% and 98.0%, respectively. The adsorption regi me of either methyl blue or Cr(VI for PVI-TFSI was in correspondence with the Langmuir adsorption model. The maximum adsorption capacity of PVI-TFSI for methyl blue and Cr(VI was determined as 476.2 and 17.9 mg/g, respectively. The hydrophobic poly(ionic liquid with a remarkable adsorbent capacity of methyl blue and Cr(VI can be conveniently synthesized and shows potential in water treatment for the effective separation of organic dyes or heavy metal ions.

  8. Novel ionic polymeric hydraulic actuators

    Science.gov (United States)

    Shahinpoor, Mohsen; Kim, Kwang J.

    2001-07-01

    It is now well recognized that a strip of ionic polymer- metal composite (IPMC) exhibits a spontaneous bending capability under the influence of an electric potential. A key observation is the appearance and disappearance of water on the expansion and contraction surfaces of the strip, respectively. Such water appearing/disappearing activities occur near the permeable metal electrodes. The imposition of en elctric field causes the mobile cations that are conjugated to the polymeric anions to undergo electrophoretic dynamic migration that can result in local deformation of the material. Such an electrophoretic behavior of the IPMC causes the water to leak out of the permeable electroded boundary so as to lower the actuation performance. This situation is similar to a leaking hydraulic actuator (hydraulic jack), which has the highest force density notwithstanding the compressor unit weight. Herein, a new category of actuators as ionic polymeric hydraulic actuators (IPHA's) is defined. The IPMC is a good example of such ionic polymeric hydraulic actuators. The advantage of ionic polymeric hydraulic actuators is their potential to generate substantially high force densities, theoretically better than current hydraulic actuators. Based upon this ionic polymer hydraulic actuator concept, a certain manufacturing technique was developed to increase the force density of the conventional IPMC's by a factor of two (100% improvement in force). This technology and associated experimental results are presented in this paper.

  9. The horizontal transfer of antibiotic resistance genes is enhanced by ionic liquid with different structure of varying alkyl chain length.

    Science.gov (United States)

    Wang, Qing; Lu, Qian; Mao, Daqing; Cui, Yuxiao; Luo, Yi

    2015-01-01

    Antibiotic resistance genes (ARGs) have become a global health concern. In our previous study, an ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm][PF6]) had been proven to facilitate the dissemination of ARGs in the environment. However, enhanced alkyl group chain length or the substitution of alkyl groups with the cation ring corresponded with increased antimicrobial effects. In this study, we investigated how different structures of ILs with 4, 6, and 8 C atoms in the longer alkyl chain on the imidazolium cations facilitated the dissemination of ARGs. The promotion of plasmid RP4 transfer frequency decreased with [CnMIM][BF4] increasing the alkyl chain length from 4 carbon atoms to 8 carbon atoms on the imidazolium cations, which is observed with [BMIM][BF4] (n = 4, 5.9 fold) > HMIM][BF4] (n = 6, 2.2 fold) > [OMIM][BF4] (n = 8, 1.7 fold). This illustrates that [CnMIM][BF4] with increasing the alkyl chain length exert decreasing ability in facilitating plasmid RP4 horizontal transfer, which is possibly related to IL-structure dependent toxicity. The IL-structure dependent plasmid RP4 transfer frequency was attributable to bacterial cell membrane permeability weaken with increasing alkyl chain length of [CnMIM][PF4], which was evidenced by flow cytometry. In freshwater microcosm, [CnMIm][BF4] promoted the relative abundance of the sulI and intI genes for 4.6 folds, aphA and traF for 5.2 folds higher than the untreated groups, promoting the propagation of ARGs in the aquatic environment. This is the first report that ILs with different structure of varying alkyl chain length facilitate horizontal transfer of plasmid RP4 which is widely distributed in the environment, and thus add the adverse effects of the environmental risk of ILs.

  10. The horizontal transfer of antibiotic resistance genes is enhanced by ionic liquid with different structure of varying alkyl chain length

    Directory of Open Access Journals (Sweden)

    Qing eWang

    2015-08-01

    Full Text Available Antibiotic resistance genes (ARGs have become a global health concern. In our previous study, an ionic liquid (IL 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm][PF6] had been proven to facilitate the dissemination of ARGs in the environment. However, enhanced alkyl group chain length or the substitution of alkyl groups with the cation ring corresponded with increased antimicrobial effects. In this study, we investigated how different structures of ILs with 4, 6 and 8 C atoms in the longer alkyl chain on the imidazolium cations facilitated the dissemination of ARGs. The promotion of plasmid RP4 transfer frequency decreased with [CnMIM][BF4] increasing the alkyl chain length from 4 carbon atoms to 8 carbon atoms on the imidazolium cations, which is observed with [BMIM][BF4] (n=4, 5.9 fold> HMIM][BF4] (n=6, 2.2 fold> [OMIM][BF4] (n=8, 1.7 fold. This illustrates that [CnMIM][BF4] with increasing the alkyl chain length exert decreasing ability in facilitating plasmid RP4 horizontal transfer, which is possibly related to IL-structure dependent toxicity. The IL-structure dependent plasmid RP4 transfer frequency was attributable to bacterial cell membrane permeability weaken with increasing alkyl chain length of [CnMIM][PF4], which was evidenced by flow cytometry (FCM. In freshwater microcosm, [CnMIm][BF4] promoted the relative abundance of the sulI and intI genes for 4.6 folds, aphA and traF for 5.2 folds higher than the untreated groups, promoting the propagation of ARGs in the aquatic environment. This is the first report that ILs with different structure of varying alkyl chain length facilitate horizontal transfer of plasmid RP4 which is widely distributed in the environment, and thus add the adverse effects of the environmental risk of ILs.

  11. A wave-function based approach for polarizable charge model: Systematic comparison of polarization effects on protic, aprotic, and ionic liquids.

    Science.gov (United States)

    Nakano, Hiroshi; Yamamoto, Takeshi; Kato, Shigeki

    2010-01-28

    We first describe a wave-function based formalism of polarizable charge model by starting from the Hartree product ansatz for the total wave function and making the second-order expansion of individual molecular energies with the use of partial charge operators. The resulting model is shown to be formally equivalent to the charge response kernel model that starts from the linear-response approximation to partial charges, and also closely related to a family of fluctuating charge models that are based on the electronegativity equalization principle. We then apply the above model to a systematic comparison of polarization effects on qualitatively different liquids, namely, protic solvents (water and methanol), an aprotic polar solvent (acetonitrile), and imidazolium-based ionic liquids. Electronic polarization is known to decelerate molecular motions in conventional solvents while it accelerates them in ionic liquids. To obtain more insights into these phenomena, we consider an effective decomposition of total polarization energy into molecular contributions, and show that their statistical distribution is well-correlated with the acceleration/deceleration of molecular motions. In addition, we perform effective nonpolarizable simulations based on mean polarized charges, and compare them with fully polarizable simulations. The result shows that the former can reproduce structural properties of conventional solvents rather accurately, while they fail qualitatively to reproduce acceleration of molecular motions in ionic liquids.

  12. Highly conductive ionic liquids toward high-performance space-lubricating greases.

    Science.gov (United States)

    Fan, Xiaoqiang; Wang, Liping

    2014-08-27

    Although ionic liquids (ILs) as a class of promising materials have a wide range of applications due to the excellent properties, their potential as space lubricants has been not systematically explored. Here two kinds of conductive alkyl imidazolium ILs greases were prepared using 1-hexyl-3-methylimidazolium tetrafluoroborate (LB106) and 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl) amide (L-F106) as base oil and the polytetrafluoroethylene (PTFE) as thickener, with multiple-alkylated cyclopentane grease (MACs) as a comparison. Their chemical composition and tribological properties were investigated in detail under simulated space environment which is composed of high vacuum, high temperature and irradiation. Results show that the high conductive ILs greases not only possess good adaptive abilities to space environment and thermal stability but also provide excellent friction reducing and antiwear behaviors as well as high load carrying capacities. The unique physicochemical properties are attributed to a combination of special anions and cations, the excellent tribological properties are strongly dependent on a boundary protective film on the rubbing surfaces.

  13. Extraction of Proanthocyanidins and Anthocyanins from Grape Skin by Using Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Natka Ćurko

    2017-01-01

    Full Text Available In this study, eight diff erent types of imidazolium-based ionic liquids (ILs were applied as new solvents in the extraction of fl avonoids from grape skin, and compared to the conventional organic solvent extraction that was not reported earlier. The structure of anions, cations and concentration of ILs signifi cantly aff ected extraction yields. The highest mass fractions of proanthocyanidins and anthocyanins were obtained with 2.5 mol/L of 1-butyl-3-methylimidazolium bromide [C4mim][Br] and 2.5 mol/L of 1-ethyl-3-methylimidazolium bromide [C2mim][Br], respectively. The studied ILs provided an excellent preliminary result in the extraction of anthocyanins. Signifi cantly higher mass fractions of total and all free anthocyanins were extracted with 2.5 mol/L of [C2mim][Br] and 2.5 mol/L of 1-methylimidazolium hydrogen sulfate [mim][HSO4] than with conventional solvent with the exception of anthocyanin-3-O-acetylmonoglucosides in the latt er. On the other hand, 2.5 mol/L of [C4mim][Br] and 2.5 mol/L of 1-(4-sulfobutyl-3-methylimidazolium hydrogen sulfate [sC4mim][HSO4] showed signifi cantly higher selectivity towards anthocyanin-3-O-acetylmonoglucosides and anthocyanin-3-(6-O-p-coumaroylmonoglucosides.

  14. Solvent extraction of Th(IV) from aqueous solution with methylimidazole in ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wenkui; Lv, Hui; Liu, Ziyi; Wu, Jianrong; Li, Shun; Shen, Yinglin [Lanzhou Univ. (China). Radiochemistry Lab.; Yang, Shenghua [State Key Laboratory of Applied Organic Chemistry, Lanzhou (China)

    2016-07-01

    An extraction of Th(IV) was performed using 1-methylimidazole (1-MIM) or 2-methylimidazole (2-MIM) as the extractant in imidazolium type ionic liquids (ILs) or n-pentanol. The extractability for Th{sup 4+} in ILs was by far higher than that obtained in n-pentanol. The extraction mechanism was determined by slope analysis and ESI-MS. The transfer of Th{sup 4+} with MIM into ILs proceeded through both a cationic exchange and a neutral solvation mechanism, whereas the partitioning of Th{sup 4+} with MIM into n-pentanol only underwent a neutral solvation mechanism. The thermodynamic parameters values (ΔH, ΔS and ΔG) for extraction of Th{sup 4+} with 1-MIM in IL were calculated and the results indicated the extraction reaction was spontaneous and went through endothermic process. Separation of Th{sup 4+} from the solution of lanthanides (III) and uranium was also carried out by 1-MIM in ILs and n-pentanol.

  15. Photochemical Transformation of Four Ionic Liquid Cation Structures in Aqueous Solution.

    Science.gov (United States)

    Pati, Sarah G; Arnold, William A

    2017-10-17

    Ionic liquids (ILs) are a new class of solvents expected to be used increasingly by the chemical industry in the coming years. Given their slow biodegradation and limited sorption affinities, IL cations have a high potential to reach aquatic environments. We investigated the fate of ILs in sunlit surface water by determining direct and indirect photochemical transformation rates of imidazolium, pyridinium, pyrrolidinium, and piperidinium cations. The photodegradation of all investigated IL cations was faster in solutions containing dissolved organic matter (DOM) than in ultrapure water, illustrating the importance of indirect photochemical processes. Experiments with model sensitizers and DOM isolates revealed that reactions with hydroxyl radicals dominated the transformation of tested IL cations. Bimolecular reaction rate constants with hydroxyl radicals ranged from (2.04 ± 0.37) × 10(9) to (8.47 ± 0.97) × 10(9) M(-1) s(-1) and showed an increase in rate constants with increasing carbon side-chain length. Consequently, average estimated half-lives of IL cations in sunlit surface water ranged from 32 ± 4 to 135 ± 25 days, highlighting the potential of IL cations to become persistent aquatic contaminants.

  16. Small-angle neutron scattering study of a dense microemulsion system formed with an ionic liquid.

    Science.gov (United States)

    Kang, T; Qian, S; Smith, G S; Do, C; Heller, W T

    2017-10-11

    Mixtures of water, octane and 1-octanol with 1-tetradecyl-3-methylimidazolium chloride (C14MIM·Cl), often referred to as a surface active ionic liquid (SAIL), form water-in-oil microemulsions that have potential application as extraction media for various metal ions. Here, we present a structural study by small-angle neutron scattering (SANS) of dense microemulsions formed by surfactant-rich mixtures of these four compounds to understand how the SAIL can be used to tune the structures and properties of the microemulsions. The SANS experiments revealed that the microemulsions formed are composed of two phases, a water-in-oil microemulsion and a bicontinuous microemulsion, which becomes the dominant phase at high surfactant concentration. In this concentration regime, the surfactant film becomes more rigid, having a higher bending modulus that results from the parallel stacking of the imidazolium ring of the SAIL. At lower surfactant concentrations, the molecular packing of the SAIL does not change with the water content of the microemulsion. The results presented here correlate well with previously observed changes in the interaction between the IL cation and metal ions (Y. Tong, L. Han and Y. Yang, Ind. Eng. Chem. Res., 2012, 51, 16438-16443), while the capacity of the microemulsion system for water remains high enough for using the system as an extraction medium.

  17. Highly Sulfonated Diamine Synthesized Polyimides and Protic Ionic Liquid Composite Membranes Improve PEM Conductivity

    Directory of Open Access Journals (Sweden)

    Bor-Kuan Chen

    2015-06-01

    Full Text Available A novel sulfonated diamine was synthesized from 1,4-bis(4-aminophenoxy benzene [pBAB]. Sulfonated polyimides (SPIs were synthesized from sulfonated pBAB, 1,4-bis(4-aminophenoxy-2-sulfonic acid benzenesulfonic acid [pBABTS], various diamines and aromatic dianhydrides. Composite proton exchange membranes (PEMs made of novel SPIs and a protic ionic liquid (PIL 1-vinyl-3-H-imidazolium trifluoromethanesulfonate [VIm][OTf] showed substantially increased conductivity. We prepared an SPI/PIL composite PEM using pBABTS, 4,4′-(9-fluorenylidene dianiline (9FDA as diamine, 3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride (DSDA as dianhydride and 40 wt % [VIm][OTf] with a high conductivity of 16 mS/cm at 120 °C and anhydrous condition. pBABTS offered better conductivity, since the chemical structure had more sulfonated groups that provide increased conductivity. The new composite membrane could be a promising anhydrous or low-humidity PEM for intermediate or high-temperature fuel cells.

  18. New eutectic ionic liquids for lipase activation and enzymatic preparation of biodiesel†

    Science.gov (United States)

    Zhao, Hua; Baker, Gary A.; Holmes, Shaletha

    2012-01-01

    The enzymatic preparation of biodiesel has been hampered by the lack of suitable solvents with desirable properties such as high lipase compatibility, low cost, low viscosity, high biodegradability, and ease of product separation. Recent interest in using ionic liquids (ILs) as advanced reaction media has led to fast reaction rates and high yields in the enzymatic synthesis of biodiesel. However, conventional (i.e., cation–anion paired) ILs based on imidazolium and other quaternary ammonium salts remain too expensive for wide application at industrial scales. In this study, we report on newly-synthesized eutectic ILs derived from choline acetate or choline chloride coupled with biocompatible hydrogen-bond donors, such as glycerol. These eutectic solvents have favorable properties including low viscosity, high biodegradability, and excellent compatibility with Novozym® 435, a commercial immobilized Candida antarctica lipase B. Furthermore, in a model biodiesel synthesis system, we demonstrate high reaction rates for the enzymatic transesterification of Miglyol® oil 812 with methanol, catalyzed by Novozym® 435 in choline acetate/glycerol (1 : 1.5 molar ratio). The high conversion (97%) of the triglyceride obtained within 3 h, under optimal conditions, suggests that these novel eutectic solvents warrant further exploration as potential media in the enzymatic production of biodiesel. PMID:21283901

  19. Novel polymeric ionic liquid microspheres with high exchange capacity for fast extraction of plasmid DNA.

    Science.gov (United States)

    Wang, Xiaofeng; Xing, Ligang; Shu, Yang; Chen, Xuwei; Wang, Jianhua

    2014-07-21

    A novel polymeric ionic liquid (PIL) microsphere, poly(1-vinyl-3-(2-methoxy-2-oxyl ethyl)imidazolium) hexafluorophosphate, is prepared via W/O emulsion polymerization. Rapid ion-exchange between the anionic moieties of PIL and DNA fragments is demonstrated facilitating the exchange equilibrium to be reached within 1 min. The PIL microspheres exhibit a high capacity of 190.7 μg mg(-1) for DNA adsorption. A fast DNA isolation protocol is thus developed with the PIL microspheres as solid phase adsorbent. It is feasible to facilitate DNA adsorption or stripping from the microspheres by simply regulating the concentration of salt. DNA adsorption is facilitated at low salt concentration, while higher concentration of salt entails DNA recovery from the microspheres. In practice, the retained DNA could be readily recovered with 1.0 mol L(-1) NaCl as stripping reagent, giving rise to a recovery of ca. 80.7%. The PIL microspheres are used for the adsorption/isolation of plasmid DNA from E. coli cell culture, demonstrating a superior adsorption performance with respect to that achieved by a commercial Plasmid Miniprep Kit. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Extraction of Biomolecules Using Phosphonium-Based Ionic Liquids + K3PO4 Aqueous Biphasic Systems

    Science.gov (United States)

    Louros, Cláudia L. S.; Cláudio, Ana Filipa M.; Neves, Catarina M. S. S.; Freire, Mara G.; Marrucho, Isabel M.; Pauly, Jérôme; Coutinho, João A. P.

    2010-01-01

    Aqueous biphasic systems (ABS) provide an alternative and efficient approach for the extraction, recovery and purification of biomolecules through their partitioning between two liquid aqueous phases. In this work, the ability of hydrophilic phosphonium-based ionic liquids (ILs) to form ABS with aqueous K3PO4 solutions was evaluated for the first time. Ternary phase diagrams, and respective tie-lines and tie-lines length, formed by distinct phosphonium-based ILs, water, and K3PO4 at 298 K, were measured and are reported. The studied phosphonium-based ILs have shown to be more effective in promoting ABS compared to the imidazolium-based counterparts with similar anions. Moreover, the extractive capability of such systems was assessed for distinct biomolecules (including amino acids, food colourants and alkaloids). Densities and viscosities of both aqueous phases, at the mass fraction compositions used for the biomolecules extraction, were also determined. The evaluated IL-based ABS have been shown to be prospective extraction media, particularly for hydrophobic biomolecules, with several advantages over conventional polymer-inorganic salt ABS. PMID:20480041

  1. Effects of Cationic Pendant Groups on Ionic Conductivity for Anion Exchange Membranes: Structure Conductivity Relationships

    Science.gov (United States)

    Kim, Sojeong; Choi, Soo-Hyung; Lee, Won Bo

    Anion exchange membranes(AEMs) have been widely studied due to their various applications, especially for Fuel cells. Previous proton exchange membranes(PEMs), such as Nafions® have better conductivity than AEMs so far. However, technical limitations such as slow electrode kinetics, carbon monoxide (CO) poisoning of metal catalysts, high methanol crossover and high cost of Pt-based catalyst detered further usages. AEMs have advantages to supplement its drawbacks. AEMs are environmentally friendly and cost-efficient. Based on the well-defined block copolymer, self-assembled morphology is expected to have some relationship with its ionic conductivity. Recently AEMs based on various cations, including ammonium, phosphonium, guanidinium, imidazolium, metal cation, and benzimidazolium cations have been developed and extensively studied with the aim to prepare high- performance AEMs. But more fundamental approach, such as relationships between nanostructure and conductivity is needed. We use well-defined block copolymer Poly(styrene-block-isoprene) as a backbone which is synthesized by anionic polymerization. Then we graft various cationic functional groups and analysis the relation between morphology and conductivity. Theoretical and computational soft matter lab.

  2. Theoretical investigations on C60 -ionic liquid interactions and their impacts on C60 dispersion behavior.

    Science.gov (United States)

    Wang, Zhuang; Tang, Lili; Peijnenburg, Willie J G M

    2014-08-01

    Increased use and production of carbon nanomaterials (e.g., fullerene C60 ) and ionic liquids (ILs) may result in their concomitant releases into the environment. Inevitably there will be interactions between carbon nanoparticles (CNPs) and ILs. However, experimental data on the interaction of CNPs with ILs are not readily available, and the mechanism behind the interactions is still elusive. To contribute to an understanding of the molecular interactions established between CNPs and ILs, theoretical investigations at multiple levels were performed to determine the interactions of C60 with 6 different imidazolium-based ILs. The results indicate that C60 mainly interacts with the IL molecules through the van der Waals, π-cation, and hydrophobic interactions. Mulliken population analysis suggests that charge transfer occurs from the IL to C60 during the C60 -IL interaction. The self-diffusion coefficient (D) of C60 in [C60  + IL] systems reaches the maximum in the case of moderate C60 -IL interaction (interaction energy, EINT ), implying that in this case a good dispersion of an agglomerate species of C60 is obtained. The D value of C60 in [C60  + IL +water] systems increases with an increase of the EINT , implying that the presence of ILs can play an important role in the aqueous dispersion of the C60 agglomerate. © 2014 SETAC.

  3. Ionic Liquid Coatings for Titanium Surfaces: Effect of IL Structure on Coating Profile.

    Science.gov (United States)

    Gindri, Izabelle M; Siddiqui, Danyal A; Frizzo, Clarissa P; Martins, Marcos A P; Rodrigues, Danieli C

    2015-12-16

    Dicationic imidazolium-based ionic liquids (ILs) having bis(trifluoromethylsulfonyl)imide (NTf2) and amino acid-based (methionine and phenylalanine) anionic moieties were synthesized and used to coat titanium surfaces using a dip-coating technique. Dicationic moieties with varying alkyl chains (8 and 10 carbons) and anions with distinct characteristics were selected to understand the influence of IL structural features on deposition profile. X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) were used in this study to help elucidate intermolecular interactions within ILs as well as between ILs and TiO2 surfaces and to investigate IL coating morphology. Charge concentration on IL moieties, as well as the presence of functional groups that can interact via hydrogen bond, such as carboxylate and amino groups, were observed to influence the deposition profile. ILs containing amino acids as the anionic moiety were observed to interact strongly with TiO2, which resulted in more pronounced changes in Ti 2p binding energy. The higher hydrophobicity of the IL having NTf2 as the anionic moiety resulted in higher adhesion strength between the IL coating and TiO2.

  4. Nucleation and growth of microdroplets of ionic liquids deposited by physical vapor method onto different surfaces

    Science.gov (United States)

    Costa, José C. S.; Coelho, Ana F. S. M. G.; Mendes, Adélio; Santos, Luís M. N. B. F.

    2018-01-01

    Nanoscience and technology has generated an important area of research in the field of properties and functionality of ionic liquids (ILs) based materials and their thin films. This work explores the deposition process of ILs droplets as precursors for the fabrication of thin films, by means of physical vapor deposition (PVD). It was found that the deposition (by PVD on glass, indium tin oxide, graphene/nickel and gold-coated quartz crystal surfaces) of imidazolium [C4mim][NTf2] and pyrrolidinium [C4C1Pyrr][NTf2] based ILs generates micro/nanodroplets with a shape, size distribution and surface coverage that could be controlled by the evaporation flow rate and deposition time. No indication of the formation of a wetting-layer prior to the island growth was found. Based on the time-dependent morphological analysis of the micro/nanodroplets, a simple model for the description of the nucleation process and growth of ILs droplets is presented. The proposed model is based on three main steps: minimum free area to promote nucleation; first order coalescence; second order coalescence.

  5. Thermophysical properties of energetic ionic liquids/nitric acid mixtures: Insights from molecular dynamics simulationsa)

    Science.gov (United States)

    Hooper, Justin B.; Smith, Grant D.; Bedrov, Dmitry

    2013-09-01

    Molecular dynamics (MD) simulations of mixtures of the room temperature ionic liquids (ILs) 1-butyl-4-methyl imidazolium [BMIM]/dicyanoamide [DCA] and [BMIM][NO3-] with HNO3 have been performed utilizing the polarizable, quantum chemistry based APPLE&P® potential. Experimentally it has been observed that [BMIM][DCA] exhibits hypergolic behavior when mixed with HNO3 while [BMIM][NO3-] does not. The structural, thermodynamic, and transport properties of the IL/HNO3 mixtures have been determined from equilibrium MD simulations over the entire composition range (pure IL to pure HNO3) based on bulk simulations. Additional (non-equilibrium) simulations of the composition profile for IL/HNO3 interfaces as a function of time have been utilized to estimate the composition dependent mutual diffusion coefficients for the mixtures. The latter have been employed in continuum-level simulations in order to examine the nature (composition and width) of the IL/HNO3 interfaces on the millisecond time scale.

  6. Acetone-soluble cellulose acetate extracted from waste blended fabrics via ionic liquid catalyzed acetylation.

    Science.gov (United States)

    Sun, Xunwen; Lu, Canhui; Zhang, Wei; Tian, Dong; Zhang, Xinxing

    2013-10-15

    Isolation of cellulose from waste polyester/cotton blended fabrics (WBFs) is a bottleneck for recycling and exploiting waste textiles. The objective of this study was to provide a new environmental-friendly and efficient approach for extracting cellulose derivatives and polyester from WBFs. A Bronsted acidic ionic liquid (IL) N-methyl-imidazolium bisulfate, [Hmim]HSO4, was used as a novel catalyst for acetylation of cellulose rather than a solvent with the aim to overcome low isolation efficiency associated with the very high viscosity and relatively high costs of ILs. The extraction yield of acetone-soluble cellulose acetate (CA) was 49.3%, which corresponded to a conversion of 84.5% of the cellulose in the original WBFs; meanwhile, 96.2% of the original poly(ethylene terephthalate) (PET) was recovered. The extracted CA was characterized by (1)H NMR, FTIR, XRD and TGA analysis, and the results indicated that high purity acetone-soluble CA and carbohydrate-free PET could be isolated in this manner from WBFs. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Synthesis and characterization of gold nanoparticles in a self-assembled ionic liquid polymer nanocomposite

    Science.gov (United States)

    Magurudeniya, Harsha; Ringstrand, Bryan; Jungjohann, Katherine; Firestone, Millicent

    Incorporation of nanoparticles(NPs) into polymer matrices has attracted interest, offering a means to create multi-functional materials combining the attributes of polymers (flexibility, processability, mechanical durability) with the opto-electrical properties of NPs. Synthesis of a self-supporting, hierarchically structured Au NP-network polymer was accomplished via a ``one-pot'' reaction employing a mesophase of AuCl3 and an imidazolium based-ionic liquid (IL) containing a acrylate group. In-situ generation of NPs was achieved by reduction of Au3+which in turn yields concomitant initiation of the polymerization of the mesophase. FT-IR and thermal analysis confirmed acrylate cross-linking. X-ray scattering confirms preservation of the mesophase within the NP composite. TEM showed a distribution of the NPs within the composite of primarily non-spherical morphologies. The co-integration of a macromer, PEG diacrylate, served as a reducing agent for the Au and the amount incorporated into the mesophase allowed for manipulation of the swelling factor of the resultant nanocomposite in a ethanol, providing means to modulate the plasmonic resonance of the NPs. This methodology provides means for organizing NPs within the structured regions of the poly(IL) matrix. Such composites may be of interest for photonic/sensing applications.

  8. Carnitine alkyl ester bromides as novel biosourced ionic liquids, cationic hydrotropes and surfactants.

    Science.gov (United States)

    Häckl, Katharina; Mühlbauer, Andrea; Ontiveros, Jesús F; Marinkovic, Sinisa; Estrine, Boris; Kunz, Werner; Nardello-Rataj, Véronique

    2017-09-28

    In contrast to anionic and nonionic amphiphilic substances, bio-based cationic ones are very rare. Cationic amphiphiles are mostly based on quaternary ammonium, pyridinium or imidazolium groups that are either badly biodegradable or have toxic residues even after degradation. In the search for green alternatives to cationic hydrotropes and amphiphiles, natural l-carnitine could be a promising candidate for a cationic headgroup. By esterification of carnitine in one step and with low cost, cationic molecules with alkyl chain length of n=2-14 could be obtained. Their thermal properties, aggregation behaviour and cytotoxicity were determined. Hydrophobic compounds were solubilized in their aqueous solutions and the PIT-slope method was applied to determine a relative hydrophilicity. It was found that some pure carnitine ester bromides were liquid at room temperature and thus can be classified as ionic liquids. They are highly water-soluble, and in aqueous solutions, they showed hydrotrope or surfactant behaviour depending on their alkyl chain length. Their high hydrotropic efficiency was demonstrated by solubilizing Disperse Red 13, while also biomolecules, like vanillin, could be dissolved in reasonable amounts. In all tests, they performed at least as good as the tested reference substances, while showing similar cytotoxicity towards human skin keratinocytes, thus demonstrating their potential as green functional amphiphilic molecules of positive charge. Copyright © 2017. Published by Elsevier Inc.

  9. Improved extraction of fluoroquinolones with recyclable ionic-liquid-based aqueous biphasic systems.

    Science.gov (United States)

    Almeida, Hugo F D; Freire, Mara G; Marrucho, Isabel M

    2016-05-07

    In the past few years, the improvement of advanced analytical tools allowed to confirm the presence of trace amounts of metabolized and unchanged active pharmaceutical ingredients (APIs) in wastewater treatment plants (WWTPs) as well as in freshwater surfaces. It is known that the continuous contact with APIs, even at very low concentrations (ng L(-1)-μg L(-1)), leads to serious human health problems. In this context, this work shows the feasibility of using ionic-liquid-based aqueous biphasic systems (IL-based ABS) in the extraction of quinolones present in aqueous media. In particular, ABS composed of imidazolium- and phosphonium-based ILs and aluminium-based salts (already used in water treatment plants) were evaluated in one-step extractions of six fluoroquinolones (FQs), namely ciprofloxacin, enrofloxacin, moxifloxacin, norfloxacin, ofloxacin and sarafloxacin, and extraction efficiencies up to 98% were obtained. Despite the large interest devoted to IL-based ABS as extractive systems of outstanding performance, their recyclability/reusability has seldomly been studied. An efficient extraction/cleaning process of the IL-rich phase is here proposed by FQs induced precipitation. The recycling of the IL and its further reuse without losses in the ABS extractive performance for FQs were established, as confirmed by the four consecutive removal/extraction cycles evaluated. This novel recycling strategy supports IL-based ABS as sustainable and cost-efficient extraction platforms.

  10. Fabrication of robust Antheraea assama fibroin nanofibrous mat using ionic liquid for skin tissue engineering.

    Science.gov (United States)

    Srivastava, Chandra Mohan; Purwar, Roli

    2016-11-01

    Electrospinning is an emerging technique used for fabrication of nanofibrous mats for skin tissue engineering applications. The aim of this study centered on fabrication of muga fibroin electrospun mats by using ionic liquid and its characterizations. The muga fibroin extracted from cocoon of Antheraea assama is dissolved in 1-butyl, 3-methyl imidazolium acetate (BMIMAc), a green solvent, to prepare a dope solution for electrospinning. The molecular weight, rheology and structural properties of dope solution are characterized. The process parameters of electrospinning machine such as voltage and concentration of dope solution are varied to obtain nanofibrous mats. The nanofibrous mat having average fiber diameter of 160nm are obtained from 10% w/v concentration of muga fibroin in BMIMAc with an applied voltage of 20KV. The mechanical, structural, physical and thermal properties of muga nanofibrous mat (MNF) are analyzed and compare with muga cast film. The cytocompatibility test is performed using L929 fibroblast cells. It is observed that muga nanofibrous mat support higher growth of fibroblast cells (pgentamycin sulphate. The release rate and antimicrobial efficiency of gentamycin sulphate loaded muga nanofibrous mat are found to be significantly higher (p<0.05) as compared to muga cast film. All these results indicate that muga nanofibrous mat would be a promising material for skin tissue engineering. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Lithium ion conducting ionic electrolytes

    Science.gov (United States)

    Angell, C. Austen; Xu, Kang; Liu, Changle

    1996-01-01

    A liquid, predominantly lithium-conducting, ionic electrolyte is described which has exceptionally high conductivity at temperatures of 100.degree. C. or lower, including room temperature. It comprises molten lithium salts or salt mixtures in which a small amount of an anionic polymer lithium salt is dissolved to stabilize the liquid against recrystallization. Further, a liquid ionic electrolyte which has been rubberized by addition of an extra proportion of anionic polymer, and which has good chemical and electrochemical stability, is described. This presents an attractive alternative to conventional salt-in-polymer electrolytes which are not cationic conductors.

  12. Lithium ion conducting ionic electrolytes

    Science.gov (United States)

    Angell, C.A.; Xu, K.; Liu, C.

    1996-01-16

    A liquid, predominantly lithium-conducting, ionic electrolyte is described which has exceptionally high conductivity at temperatures of 100 C or lower, including room temperature. It comprises molten lithium salts or salt mixtures in which a small amount of an anionic polymer lithium salt is dissolved to stabilize the liquid against recrystallization. Further, a liquid ionic electrolyte which has been rubberized by addition of an extra proportion of anionic polymer, and which has good chemical and electrochemical stability, is described. This presents an attractive alternative to conventional salt-in-polymer electrolytes which are not cationic conductors. 4 figs.

  13. 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).

  14. 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.

  15. An ether-functionalised cyclic sulfonium based ionic liquid as an electrolyte for electrochemical double layer capacitors

    Science.gov (United States)

    Neale, Alex R.; Murphy, Sinead; Goodrich, Peter; Schütter, Christoph; Hardacre, Christopher; Passerini, Stefano; Balducci, Andrea; Jacquemin, Johan

    2016-09-01

    A novel cyclic sulfonium cation-based ionic liquid (IL) with an ether-group appendage and the bis{(trifluoromethyl)sulfonyl}imide anion was synthesised and developed for electrochemical double layer capacitor (EDLC) testing. The synthesis and chemical-physical characterisation of the ether-group containing IL is reported in parallel with a similarly sized alkyl-functionalised sulfonium IL. Results of the chemical-physical measurements demonstrate how important transport properties, i.e. viscosity and conductivity, can be promoted through the introduction of the ether-functionality without impeding thermal, chemical or electrochemical stability of the IL. Although the apparent transport properties are improved relative to the alkyl-functionalised analogue, the ether-functionalised sulfonium cation-based IL exhibits moderately high viscosity, and poorer conductivity, when compared to traditional EDLC electrolytes based on organic solvents (propylene carbonate and acetonitrile). Electrochemical testing of the ether-functionalised sulfonium IL was conducted using activated carbon composite electrodes to inspect the performance of the IL as a solvent-free electrolyte for EDLC application. Good cycling stability was achieved over the studied range and the performance was comparable to other solvent-free, IL-based EDLC systems. Nevertheless, limitations of the attainable performance are primarily the result of sluggish transport properties and a restricted operative voltage of the IL, thus highlighting key aspects of this field which require further attention.

  16. 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.

  17. Determination of Structural Requirements of N-Substituted Tetrahydro-β-Carboline Imidazolium Salt Derivatives Using in Silico Approaches for Designing MEK-1 Inhibitors.

    Science.gov (United States)

    Liang, Jingwei; Wang, Mingyang; Li, Xinyang; He, Xin; Cao, Chong; Meng, Fanhao

    2017-06-19

    Novel N-substituted tetrahydro-β-carboline imidazolium salt derivatives proved to have potent antitumor activity in past research. The Topomer CoMFA and CoMSIA function in Sybyl-X 2.0 software was applied for the identification of important features of N-substituted tetrahydro-β-carboline-imidazolium salt derivative moieties. In the case of Topomer CoMFA, all the compounds were split into two fragments which were used to generate a 3D invariant representation, the statistical results of the Topomer CoMFA model: q² value of 0.700; r² value of 0.954; with 5 optimum components. The database alignment was utilized for building the CoMSIA model, and the CoMSIA model had q² and r² values of 0.615 and 0.897, with 4 optimum components. Target fishing of the PharmMapper platform was utilised for finding potential targets, the human mitogen-activated protein kinase 1 (MEK-1) was found to be the primary potential target for the three compounds with the fit scores of 6.288, 5.741, and 6.721. The molecular docking technique of MOE 2015 was carried out to identify the interactions of amino acids surrounding the ligand, and correlating QASR contour maps were used to identify structural requirements of N-substituted tetrahydro-β-carboline imidazolium salt moieties. Molecular dynamics and simulation studies proved that the target protein was stable for 0.8-5 ns. The pivotal moieties of N-substituted tetrahydro-β-carboline imidazolium salt derivatives and its potential targets were verified by the QASR study, PharmMapper, and the molecular docking study which would be helpful to design novel MEK-1 inhibitors for anticancer drugs.

  18. Determination of Structural Requirements of N-Substituted Tetrahydro-β-Carboline Imidazolium Salt Derivatives Using in Silico Approaches for Designing MEK-1 Inhibitors

    Directory of Open Access Journals (Sweden)

    Jingwei Liang

    2017-06-01

    Full Text Available Novel N-substituted tetrahydro-β-carboline imidazolium salt derivatives proved to have potent antitumor activity in past research. The Topomer CoMFA and CoMSIA function in Sybyl-X 2.0 software was applied for the identification of important features of N-substituted tetrahydro-β-carboline-imidazolium salt derivative moieties. In the case of Topomer CoMFA, all the compounds were split into two fragments which were used to generate a 3D invariant representation, the statistical results of the Topomer CoMFA model: q2 value of 0.700; r2 value of 0.954; with 5 optimum components. The database alignment was utilized for building the CoMSIA model, and the CoMSIA model had q2 and r2 values of 0.615 and 0.897, with 4 optimum components. Target fishing of the PharmMapper platform was utilised for finding potential targets, the human mitogen-activated protein kinase 1 (MEK-1 was found to be the primary potential target for the three compounds with the fit scores of 6.288, 5.741, and 6.721. The molecular docking technique of MOE 2015 was carried out to identify the interactions of amino acids surrounding the ligand, and correlating QASR contour maps were used to identify structural requirements of N-substituted tetrahydro-β-carboline imidazolium salt moieties. Molecular dynamics and simulation studies proved that the target protein was stable for 0.8–5 ns. The pivotal moieties of N-substituted tetrahydro-β-carboline imidazolium salt derivatives and its potential targets were verified by the QASR study, PharmMapper, and the molecular docking study which would be helpful to design novel MEK-1 inhibitors for anticancer drugs.

  19. 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.

  20. High-flux ionic diodes, ionic transistors and ionic amplifiers based on external ion concentration polarization by an ion exchange membrane: a new scalable ionic circuit platform.

    Science.gov (United States)

    Sun, Gongchen; Senapati, Satyajyoti; Chang, Hsueh-Chia

    2016-04-07

    A microfluidic ion exchange membrane hybrid chip is fabricated using polymer-based, lithography-free methods to achieve ionic diode, transistor and amplifier functionalities with the same four-terminal design. The high ionic flux (>100 μA) feature of the chip can enable a scalable integrated ionic circuit platform for micro-total-analytical systems.

  1. High-flux ionic diodes, ionic transistors and ionic amplifiers based on external ion concentration polarization by an ion exchange membrane: a new scalable ionic circuit platform†

    Science.gov (United States)

    Sun, Gongchen; Senapati, Satyajyoti

    2016-01-01

    A microfluidic-ion exchange membrane hybrid chip is fabricated by polymer-based, lithography-free methods to achieve ionic diode, transistor and amplifier functionalities with the same four-terminal design. The high ionic flux (> 100 μA) feature of the chip can enable a scalable integrated ionic circuit platform for micro-total-analytical systems. PMID:26960551

  2. Ionic liquids as porogens in the microwave-assisted synthesis of methacrylate monoliths for chromatographic application

    Energy Technology Data Exchange (ETDEWEB)

    Singco, Brenda; Lin, Chen-Lan; Cheng, Yi-Jie; Shih, Yung-Han [Department of Chemistry and Center for Nanotechnology, CYCU (Chung Yuan Christian University), 200 Chung Pei Road, Chung-Li 320, Taiwan (China); Huang, Hsi-Ya, E-mail: hyhuang@cycu.edu.tw [Department of Chemistry and Center for Nanotechnology, CYCU (Chung Yuan Christian University), 200 Chung Pei Road, Chung-Li 320, Taiwan (China)

    2012-10-09

    Highlights: Black-Right-Pointing-Pointer An efficient and cleaner monoliths preparation utilizing ionic liquids in conjunction with microwave Black-Right-Pointing-Pointer These ionic liquids with varied cation alkyl chain and anion type successfully tuned the morphology of different alkyl methacrylates Black-Right-Pointing-Pointer Small molecules and peptide digests separated well in these monoliths. - Abstract: Several imidazolium-based ionic liquids (ILs) with varying cation alkyl chain length (C{sub 4}-C{sub 10}) and anion type (tetrafluoroborate ([BF{sub 4}]{sup -}), hexafluorophosphate ([PF{sub 6}]{sup -}) and bis(trifluoromethylsulfonyl)imide ([Tf{sub 2}N]{sup -})) were used as reaction media in the microwave polymerization of methacrylate-based stationary phases. Scanning electron micrographs and backpressures of poly(butyl methacrylate-ethylene dimethacrylate) (poly(BMA-EDMA)) monoliths synthesized in the presence of these ionic liquids demonstrated that porosity and permeability decreased when cation alkyl chain length and anion hydrophobicity were increased. Performance of these monoliths was assessed for their ability to separate parabens by capillary electrochromatography (CEC). Intra-batch precision (n = 3 columns) for retention time and peak area ranged was 0.80-1.13% and 3.71-4.58%, respectively. In addition, a good repeatability of RSD{sub Retentiontime} = <0.30% and {approx}1.0%, RSD{sub Peakarea} = <1.30% and <4.3%, and RSD{sub Efficiency} = <0.6% and <11.5% for intra-day and inter-day, respectively exemplify monolith performance reliability for poly(BMA-EDMA) fabricated using 1-hexyl-3-methylimidazolium tetrafluoroborate ([C{sub 6}mim][BF{sub 4}]) porogen. This monolith was also tested for its potential in nanoLC to separate protein digests in gradient mode. ILs as porogens also fabricated different alkyl methacrylate (AMA) (C4-C18) monoliths. Furthermore, employing binary IL porogen mixture such as 1-butyl-3-methylimidazolium tetrafluoroborate

  3. 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...

  4. Catalysis in Molten Ionic Media

    DEFF Research Database (Denmark)

    Boghosian, Soghomon; Fehrmann, Rasmus

    2013-01-01

    This chapter deals with catalysis in molten salts and ionic liquids, which are introduced and reviewed briefly, while an in-depth review of the oxidation catalyst used for the manufacturing of sulfuric acid and cleaning of flue gas from electrical power plants is the main topic of the chapter...

  5. Retarded ionic motion in flourites

    NARCIS (Netherlands)

    Schoonman, J.

    Metals halides with the fluorite structure attain conductivity values typical of ionic melts far below their melting points, and also go through a second-order transition. Conductivity data for the fluorites are reviewed, and it is shown that the anion vacancies have a large and unique mobility

  6. Olefins transformation catalysis by zirconium and tungsten complexes in organic and non-aqueous ionic media; Catalyse de transformation des olefines par les complexes du zirconium et du tungstene en milieux organique et ionique non aqueux

    Energy Technology Data Exchange (ETDEWEB)

    Laurent-Gerot, P.

    1997-06-30

    Molten salts are suitable solvents for biphasic catalysis: melting butyl-1 methyl-3 imidazolium chloride and aluminium chloride gives a polar and aprotic ionic liquid which is not miscible with hydrocarbons but dissolves organometallic complexes. Two types of complexes have been tested in molten salts with ethyl-aluminium dichloride: zirconium complexes to synthesize light {alpha} olefins from ethene; mono-imido complexes of tungsten VI (Cl{sub 4}W = NAr) to dimerize ethene in but-1 ene and propene in dimethyl-2,3-but-1-ene. For both of these complexes, biphasic catalysis principle is always respected: the active species is present only in the ionic phase and not in the organic phase. The first complexes, biphasic principle is always respected: the active species is present only in the ionic phase and not in the organic phase. The first complexes oligomerize ethene in molten salts with low activity and the {alpha} olefins selectivity is weak. Mono-imido complexes of tungsten VI are proved to be equivalent to the systems composed with WCl{sub 6} and aniline, and they dimerize ethene in but-1 ene and propene in dimethyl-2,3-but-1 ene more efficiently in organic medium than in ionic liquid. The characterization of the active species of the system Cl{sub 4}W=NAr / EtAlCl{sub 2} shows that it is the corresponding mono-imido complex of tungsten 4. (author) 129 refs.

  7. Quasi-gel-state ionic liquid electrolyte with alkyl-pyrazolium iodide for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ishimaru, Noriyo; Kubo, Wataru; Kitamura, Takayuki [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Yanagida, Shozo [Center for Advanced Science and Innovation, Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871 (Japan); Tsukahara, Yasunori [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Maitani, Masato M. [Department of Applied Chemistry, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguroku, Tokyo 152-8552 (Japan); Wada, Yuji, E-mail: yuji-w@apc.titech.ac.jp [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Department of Applied Chemistry, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguroku, Tokyo 152-8552 (Japan)

    2011-08-15

    Highlights: > The dye sensitized solar cells (DSSC) using quasi-gel-state ionic liquid electrolyte. > We synthesized 1-alkyl-2-methylpyrazolium iodides (PyI) for the electrolytes of DSSC. > The viscosity of PyI were higher than that of the imidazolium iodide electrolytes (ImI). > DSSC using the PyI exhibited the high Jsc and efficiency than that using ImI. > In PyI, the rapid diffusion of charge carriers, Grotthus-like model, was predominant. - Abstract: A series of non-volatile viscous ionic liquid, 1-alkyl-2-methylpyrazolium iodides (RPyI: R = C{sub 3}-C{sub 7}), were synthesized for the electrolyte of dye-sensitized solar cells (DSSC). Most of RPyI revealed extremely viscous quasi-gel-state electrolytes potentially preventing leakage and evaporation of electrolytes of the solar cells. A DSSC using the electrolyte composed of 1-hexyl-2-methylpyrazolium iodide (C{sub 6}PyI) with iodine exhibiting higher conversion efficiency of 3.8% (under 1 Sun) for 10% larger short-circuit photocurrent, J{sub SC}, than that with a conventional ionic liquid, 1-hexyl-3-methyllimidazolium iodide (C{sub 6}ImI) with iodine, in spite of less favorable viscosity (2013 mPa s (C{sub 6}PyI/I{sub 2}) vs. 1439 mPa s (C{sub 6}ImI/I{sub 2})) for the physical diffusion of charge carriers in the electrolyte. Furthermore, the quasi-gel-state electrolytes composed of a series of RPyI ionic liquids surprisingly exhibiting comparable J{sub SC} to that with much less viscous C{sub 6}ImI/I{sub 2}. We discuss the results of quasi-gel-state RPyI ionic liquid electrolyte for DSSC based on the Grotthus-like electron exchange mechanism of iodide redox species in the highly viscous RPyI ionic liquid evaluated qualitatively by Raman spectroscopic observation of poly-iodide species.

  8. 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.

  9. Macroscopic and microscopic study of 1-ethyl-3-methyl-imidazolium acetate-DMSO mixtures.

    Science.gov (United States)

    Radhi, Asanah; Le, Kim Anh; Ries, Michael E; Budtova, Tatiana

    2015-01-29

    Macroscopic (steady-state viscosity, density) and microscopic (NMR chemical shifts, (1)H NMR relaxation times, and diffusion) properties of the 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc])-dimethyl sulfoxide (DMSO) mixture were studied in detail as a function of DMSO molar fraction at various temperatures. Temperature dependencies were used to calculate the activation energies. NMR results indicate that at low molar fraction of DMSO (<0.4), it weakly associates with the cation and in doing so disrupts the strong ion-ion association that exists in the pure ionic liquid. Stokes-Einstein equation, which linearly correlates the diffusion coefficient of a spherical molecule and macroscopic viscosity, was shown to work well for the [EMIM][OAc]-DMSO mixture. The influence of DMSO on the "anomalous" diffusion in [EMIM][OAc] ("quick" cation vs "slow" anion) was investigated; it was demonstrated that DMSO makes the cation diffusion slower. All parameters studied showed relatively small deviations from the ideal mixing rule behavior (from 20% to 50% difference between experimental and theoretically predicted results), confirming weak interactions between the components.

  10. Synthesis and toxicity evaluation of hydrophobic ionic liquids for volatile organic compounds biodegradation in a two-phase partitioning bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Castillo, Alfredo Santiago [Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France); Université européenne de Bretagne (France); Guihéneuf, Solène, E-mail: solene.guiheneuf@wanadoo.fr [Université européenne de Bretagne, Université de Rennes 1, Sciences Chimiques de Rennes, UMR, CNRS 6226, Groupe Ingénierie Chimique & Molécules Pour le Vivant (ICMV), Bât. 10A, Campus de Beaulieu, Avenue du Général Leclerc, CS 74205, 35042 Rennes cedex (France); Le Guével, Rémy [Plate-forme ImPACcell Structure Fédérative de Recherche BIOSIT Université de Rennes 1, Bat. 8, Campus de Villejean, 2 Avenue du Pr. Leon Bernard, CS 34317, 35043 Rennes Cedex (France); Biard, Pierre-François [Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France); Université européenne de Bretagne (France); and others

    2016-04-15

    Highlights: • Description of a VOC depollution system suitable with industrial processes, TPPB. • Novel association of TPPB and hydrophobic ionic liquids. • Synthesis of several hydrophobic ionic liquids designed to fit desired properties. • Toxicity evaluation of these ILs towards cells, animals and bacteria. - Abstract: Synthesis of several hydrophobic ionic liquids (ILs), which might be selected as good candidates for degradation of hydrophobic volatile organic compounds in a two-phase partitioning bioreactor (TPPB), were carried out. Several bioassays were also realized, such as toxicity evaluation on activated sludge and zebrafish, cytotoxicity, fluoride release in aqueous phase and biodegradability in order to verify their possible effects in case of discharge in the aquatic environment and/or human contact during industrial manipulation. The synthesized compounds consist of alkylimidazoliums, functionalized imidazoliums, isoqinoliniums, triazoliums, sulfoniums, pyrrolidiniums and morpholiniums and various counter-ions such as: PF{sub 6}{sup −}, NTf{sub 2}{sup −} and NfO{sup −}. Toxicity evaluation on activated sludge of each compound (5% v/v of IL) was assessed by using a glucose uptake inhibition test. Toxicity against zebrafish and cytotoxicity were evaluated by the ImPACCell platform of Rennes (France). Fluoride release in water was estimated by regular measurements using ion chromatography equipment. IL biodegradability was determined by measuring BOD{sub 28} of aqueous samples (compound concentration,1 mM). All ILs tested were not biodegradable; while some of them were toxic toward activated sludge. Isoquinolinium ILs were toxic to human cancerous cell lines. Nevertheless no toxicity was found against zebrafish Danio rerio. Only one IL released fluoride after long-time agitation.

  11. Nonleachable Imidazolium-Incorporated Composite for Disruption of Bacterial Clustering, Exopolysaccharide-Matrix Assembly, and Enhanced Biofilm Removal.

    Science.gov (United States)

    Hwang, Geelsu; Koltisko, Bernard; Jin, Xiaoming; Koo, Hyun

    2017-11-08

    Surface-grown bacteria and production of an extracellular polymeric matrix modulate the assembly of highly cohesive and firmly attached biofilms, making them difficult to remove from solid surfaces. Inhibition of cell growth and inactivation of matrix-producing bacteria can impair biofilm formation and facilitate removal. Here, we developed a novel nonleachable antibacterial composite with potent antibiofilm activity by directly incorporating polymerizable imidazolium-containing resin (antibacterial resin with carbonate linkage; ABR-C) into a methacrylate-based scaffold (ABR-modified composite; ABR-MC) using an efficient yet simplified chemistry. Low-dose inclusion of imidazolium moiety (∼2 wt %) resulted in bioactivity with minimal cytotoxicity without compromising mechanical integrity of the restorative material. The antibiofilm properties of ABR-MC were assessed using an exopolysaccharide-matrix-producing (EPS-matrix-producing) oral pathogen (Streptococcus mutans) in an experimental biofilm model. Using high-resolution confocal fluorescence imaging and biophysical methods, we observed remarkable disruption of bacterial accumulation and defective 3D matrix structure on the surface of ABR-MC. Specifically, the antibacterial composite impaired the ability of S. mutans to form organized bacterial clusters on the surface, resulting in altered biofilm architecture with sparse cell accumulation and reduced amounts of EPS matrix (versus control composite). Biofilm topology analyses on the control composite revealed a highly organized and weblike EPS structure that tethers the bacterial clusters to each other and to the surface, forming a highly cohesive unit. In contrast, such a structured matrix was absent on the surface of ABR-MC with mostly sparse and amorphous EPS, indicating disruption in the biofilm physical stability. Consistent with lack of structural organization, the defective biofilm on the surface of ABR-MC was readily detached when subjected to low shear

  12. Vibrational Stark Effect to Probe the Electric-Double Layer of the Ionic Liquid-Metal Electrodes

    Science.gov (United States)

    Garcia Rey, Natalia; Moore, Alexander Knight; Toyouchi, Shuichi; Dlott, Dana

    2017-06-01

    Vibrational sum frequency generation (VSFG) spectroscopy is used to study the effect of room temperature ionic liquids (RTILs) in situ at the electrical double layer (EDL). RTILs have been recognized as electrolytes without solvent for applications in batteries, supercapacitors and electrodeposition^{1}. The molecular response of the RTIL in the EDL affects the performance of these devices. We use the vibrational Stark effect on CO as a probe to detect the changes in the electric field affected by the RTIL across the EDL on metal electrodes. The Stark effect is a shift in the frequency in response to an externally applied electric field and also influenced by the surrounding electrolyte and electrode^{2}. The CO Stark shift is monitored by the CO-VSFG spectra on Pt or Ag in a range of different imidazolium-based RTILs electrolytes, where their composition is tuned by exchanging the anion, the cation or the imidazolium functional group. We study the free induction decay (FID)^{3} of the CO to monitor how the RTIL structure and composition affect the vibrational relaxation of the CO. Combining the CO vibrational Stark effect and the FID allow us to understand how the RTIL electrochemical response, molecular orientation response and collective relaxation affect the potential drop of the electric field across the EDL, and, in turn, how determines the electrical capacitance or reactivity of the electrolyte/electrode interface. ^{1}Fedorov, M. V.; Kornyshev, A. A., Ionic Liquids at Electrified Interfaces. Chem. Rev. 2014, 114, 2978-3036. ^{2} (a) Lambert, D. K., Vibrational Stark Effect of Adsorbates at Electrochemical Interfaces. Electrochim. Acta 1996, 41, 623-630. (b) Oklejas, V.; Sjostrom, C.; Harris, J. M., SERS Detection of the Vibrational Stark Effect from Nitrile-Terminated SAMs to Probe Electric Fields in the Diffuse Double-Layer. J. Am. Chem. Soc. 2002, 124, 2408-2409. ^{3}Symonds, J. P. R.; Arnolds, H.; Zhang, V. L.; Fukutani, K.; King, D. A

  13. Synthesis, growth, structure, mechanical and optical properties of a new semi-organic 2-methyl imidazolium dihydrogen phosphate single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Nagapandiselvi, P., E-mail: nagapandiselvip@ssn.edu.in [Department of Physics, SSN College of Engineering, Kalavakkam (India); Baby, C. [Sophisticated Analytical Instrument Facility, Indian Institute of Technology Madras, Chennai (India); Gopalakrishnan, R. [Crystal Research Lab, Department of Physics, Anna University, Chennai (India)

    2016-09-15

    Highlights: • 2MIDP crystals were grown by slow evaporation solution growth technique. • Single crystal XRD revealed self-assembled supramolecular framework. • Z scan technique is employed for third order nonlinear optical susceptibility. • Structure-property correlation is established. - Abstract: A new semi-organic compound, 2-methyl imidazolium dihydrogen phosphate (2MIDP), was prepared and good quality single crystals of 2MIDP were grown by slow evaporation solution growth technique. Crystal structure elucidated using Single crystal XRD showed that 2MIDP crystallizes in monoclinic system with P2{sub 1}/c space group. FT-IR, UV-Vis-NIR, Fluorescence and FT-NMR spectra confirm the molecular structure of 2MIDP. The UV-Vis-NIR spectra established the suitability of the compound for NLO applications. TG-DSC showed that 2MIDP is thermally stable up to 200 °C. Mechanical characteristics like hardness number (H{sub v}), stiffness constant (C{sub 11}), yield strength (σ{sub v}), fracture toughness (K{sub c}) and brittleness index (B{sub i}) were assessed using Vicker’s microhardness tester. Third order nonlinear optical properties determined from Z-scan measurement using femto and picosecond lasers showed two photon reverse saturable absorption. The enhancement of nonlinear optical properties in femto second laser, revealed the suitability of 2MIDP for optical limiting applications.

  14. 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.

  15. 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.

  16. Evidence for enhancing charge collection efficiency with an alternative cost-effective binary ionic liquids electrolyte based dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hao Feng [State Key Laboratory of New Ceramics and Fine Processing, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China); Lin Hong, E-mail: Hong-lin@tsinghua.edu.cn [State Key Laboratory of New Ceramics and Fine Processing, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu Yizhu [State Key Laboratory of New Ceramics and Fine Processing, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China); Yang Guijun; Wang Gang [School of Mechanical Engineering, Qinghai University, Xining 810016 (China); Li Jianbao [State Key Laboratory of New Ceramics and Fine Processing, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2011-06-30

    Highlights: > Cost-effective and highly conductive binary ionic liquids electrolyte. > Dynamics of electron transport and charge recombination processes. > Significantly decreased diffusion resistance and retarded charge recombination. > Improving the effective electron diffusion length and charge collection efficiency. - Abstract: To mitigate the mass transfer limitations of a highly viscous room temperature ionic liquid (RTIL) electrolyte, systematic characterizations of viscosity, ionic conductivity, apparent triiodide diffusion coefficient and photovoltaic response of an alternative cost-effective and highly conductive binary RTIL mixture of 1-ethyl-3-methylimidazolium trifluoroacetate (EMIATF) and 1-methyl-3-propylimidazolium iodide (PMII) were investigated. An emphasis was placed on the dynamics of electron transport and charge recombination processes; specifically, a focus was placed on the effective electron diffusion length and charge collection efficiency in the devices. Notably, the introduction of perfluorinated anions, with a strong delocalization of the negative charge over the anion backbone, was able to weaken the hydrogen bonding with the imidazolium cations and, thus, decrease the viscosity and increase the ionic conductivity of the electrolyte. A sealed device that employed the binary RTIL achieved an overall conversion efficiency of 5.22% under irradiation of 100 mW cm{sup -2}, which increased the value by 30% compared to a device with a blank PMII-based RTIL electrolyte. Electrochemical impedance spectroscopy and intensity-modulated photovoltage/photocurrent spectroscopy analysis revealed that employment of this alternative binary RTIL electrolyte system was able to significantly decrease the diffusion resistance of triiodide species in the electrolyte and retard the charge recombination between the injected electrons with triiodide anions in the electrolyte, thus improving the effective electron diffusion length and charge collection

  17. 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.

  18. 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...

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

    Indian Academy of Sciences (India)

    A solid hybrid molecular material containing 1-butyl 3-methyl imidazolium cations and Keggin anions of phosphotungstic acid has been synthesized. It is fully characterized by CHN analysis, FTIR, XRD, UV-Vis-NIR DRS, 31P MAS NMR, TGA and SEM. The FTIR spectrum of the compound shows the fingerprint vibrational ...

  20. 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.

  1. 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...

  2. "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.

  3. Development of a functionalized polymeric ionic liquid monolith for solid-phase microextraction of polar endocrine disrupting chemicals in aqueous samples coupled to high-performance liquid chromatography.

    Science.gov (United States)

    Feng, Juanjuan; Sun, Min; Bu, Yanan; Luo, Chuannan

    2015-09-01

    Ionic liquids (ILs) have been efficiently used as a "designer sorbent" in sample preparation. A novel 1-(3-aminopropyl)-3-(4-vinylbenzyl)imidazolium 4-styrenesulfonate IL monomer was synthesized and copolymerized with 1,6-di(3-vinylimidazolium) hexane bishexafluorophosphate IL as cross-linking agent to prepare a cross-linked polymeric ionic liquids (PILs) monolith. Coupled to high-performance liquid chromatography (HPLC), the PILs monolith was used as a solid-phase microextraction (SPME) sorbent to extract some polar endocrine disrupting chemical (EDCs) such as estrogens, bisphenol A, and phthalate esters in aqueous samples. Preparation and extraction conditions were investigated and optimized to obtain satisfactory extraction efficiency. Limits of detection (LODs) of the proposed method for three steroid estrogens and bisphenol A were 0.25 and 0.2 μg L(-1), respectively, which were lower than or comparable to some other sample preparation methods. Intra- and inter-day repeatability for all the analytes was 2.2-12%. The monolith-to-monolith repeatability was 7.4-15%. The extraction performance of the method for analysis of target estrogens in treated domestic wastewater was investigated and compared with a dispersive liquid-liquid microextraction (DLLME) method. The proposed SPME method provided better sensitivity and higher resistance to matrix interferences.

  4. Ionic liquid supported on an electrodeposited polycarbazole film for the headspace solid-phase microextraction and gas chromatography determination of aromatic esters.

    Science.gov (United States)

    Feng, Yuanyuan; Zhao, Faqiong; Zeng, Baizhao

    2015-05-01

    A polycarbazole film was electrodeposited on a stainless-steel wire from a solution of N,N-dimethylformamide/propylene carbonate (1:9 v/v) containing 0.10 M carbazole and 0.10 M tetrabutylammonium perchlorate. The obtained polycarbazole fiber was immersed into an ionic liquid (1-hydroxyethyl-3-methyl imidazolium bis[(trifluoromethyl)sulfonyl]imide) solution (in dimethylsulfoxide) for 30 min, followed by drying under an infrared lamp. The resulting polycarbazole/ionic liquid fiber was applied to the headspace solid-phase microextraction and determination of aromatic esters by coupling with gas chromatography and flame ionization detection. Under the optimized conditions, the limits of detection were below 61 ng/L (S/N = 3) and the linear ranges were 0.061-500 μg/L with correlation coefficients above 0.9876. The relative standard deviations were below 4.8% (n = 5) for a single fiber, and below 9.9% for multi-fiber (n = 4). This fiber also exhibited good stability. It could be used for more than 160 times of headspace solid-phase microextraction and could withstand a high temperature up to 350°C. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Effect of degree of crosslinking and polymerization of 3D printable polymer/ionic liquid composites on performance of stretchable piezoresistive sensors

    Science.gov (United States)

    Lee, Jeongwoo; Faruk Emon, Md Omar; Vatani, Morteza; Choi, Jae-Won

    2017-03-01

    Ionic liquid (IL)/polymer composites (1-ethyl-3-methyl-imidazolium tetrafluoroborate (EMIMBF4)/2-[[(butylamino)carbonyl]oxy]ethyl acrylate (BACOEA)) were fabricated to use as sensing materials for stretchable piezoresistive tactile sensors. The detectability of the IL/polymer composites was enhanced because the ionic transport properties of EMIMBF4 in the composites were improved by the synergic actions between the coordinate sites generated by the local motion of BACOEA chain segments under enough activation energy. The performance of the piezoresistive sensors was investigated with the degree of crosslinking and polymerization of the IL/polymer composites. As the compressive strain was increased, the distance between two electrodes decreased, and the motion of polymer chains and IL occurred, resulting in a decrease in the electrical resistance of the sensors. We have confirmed that the sensitivity of the sensors are affected by the degree of crosslink and polymerization of the IL/polymer composites. In addition, all of the materials (skins, sensing material, and electrode) used in this study are photo-curable, and thus the stretchable piezoresistive tactile sensors can be successfully fabricated by 3D printing.

  6. How Does the Addition of a Third Ion Affect the Molecular Interactions and the Thermodynamic Properties of Acetate-Based Ionic Liquids?

    Science.gov (United States)

    Otero, I; Lepre, L F; Dequidt, A; Husson, P; Costa Gomes, M F

    2017-10-19

    The effect of the addition of a third ion to the ionic liquid 1-butyl-3-methylimidazolium acetate [C4C1Im][OAc] was studied through the measurement of the enthalpy of mixing and of the excess molar volume of its mixtures with 1-butyl-3-methylimidazolium trifluoroacetate [C4C1Im][CF3CO2], 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C4C1Im][NTf2], and tetrabutylphosphonium acetate [P4444][OAc]. Negative enthalpies of mixing (ΔmixH 0) were observed in all cases. The infrared and NMR studies of the pure ionic liquids and their mixtures show that the presence of a third ion with a weaker affinity with the common counterion contributes to prevailing the more favorable hydrogen-bond, herein always between the imidazolium cation and the acetate anion. Both radial and spatial distribution functions calculated by molecular simulation confirm this behavior. The remarkable enhancement of the viscosities of the [C4C1Im][OAc] + [P4444][OAc] mixtures could be discussed in light of the calculated friction coefficients.

  7. Green and Efficient Processing of Cinnamomum Cassia bark using Ionic Liquids: Extraction of Essential Oil and Construction of UV-Resistant Composite Films from Residual Biomass.

    Science.gov (United States)

    Mehta, Mohit; Kumar, Arvind

    2017-10-08

    There is a significant interest in development of sustainable and integrated process of extraction of essential oils and separation of biopolymers using novel and efficient solvent systems. Herein, Cassia essential oil enriched in Coumarin is extracted from Cinnamomum Cassia bark using a protic ionic liquid, ethylammonium nitrate (EAN) via dissolution and creation of a biphasic system with the help of diethyl ether. The process has been perfected in terms of higher biomass dissolution ability and essential oil yield by addition of aprotic ILs (based on 1-butyl-3-methyl imidazolium cation [Bmim] and chloride [Cl] or acetate [OAc] anion) to EAN. After extraction of oil, cellulose-rich material and free lignin were regenerated from biomass-ionic liquid solutions by using 1:1 acetone-water mixture. Purity of extracted essential oil and biopolymers were ascertained using FT-IR, NMR, and GC-MS techniques. Since, the lignin contains UV blocking chromophores, the oil free residual lignocellulosic material has been directly utilized to construct UV light resistant composite materials in conjunction with biopolymer chitosan. Composite material thus obtained was processed to make bio-degradable films which were characterized for mechanical and optical properties. The films showed excellent UV light resistance and mechanical properties thereby making it a material suitable for packaging and light-sensitive applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Application of artificial neural network for vapor liquid equilibrium calculation of ternary system including ionic liquid: Water, ethanol and 1-butyl-3-methylimidazolium acetate

    Energy Technology Data Exchange (ETDEWEB)

    Fazlali, Alireza; Koranian, Parvaneh [Arak University, Arak (Iran, Islamic Republic of); Beigzadeh, Reza [Islamic Azad University, Kermanshah (Iran, Islamic Republic of); Rahimi, Masoud [Razi University, Kermanshah (Iran, Islamic Republic of)

    2013-09-15

    A feed forward three-layer artificial neural network (ANN) model was developed for VLE prediction of ternary systems including ionic liquid (IL) (water+ethanol+1-butyl-3- methyl-imidazolium acetate), in a relatively wide range of IL mass fractions up to 0.8, with the mole fractions of ethanol on IL-free basis fixed separately at 0.1, 0.2, 0.4, 0.6, 0.8, and 0.98. The output results of the ANN were the mole fraction of ethanol in vapor phase and the equilibrium temperature. The validity of the model was evaluated through a test data set, which were not employed in the training case of the network. The performance of the ANN model for estimating the mole fraction and temperature in the ternary system including IL was compared with the non-random-two-liquid (NRTL) and electrolyte non-random-two- liquid (eNRTL) models. The results of this comparison show that the ANN model has a superior performance in predicting the VLE of ternary systems including ionic liquid.

  9. Effect of Monomer Structure on Curing Behavior, CO2 Solubility, and Gas Permeability of Ionic Liquid-Based Epoxy-Amine Resins and Ion-Gels

    Energy Technology Data Exchange (ETDEWEB)

    McDanel, WM; Cowan, MG; Barton, JA; Gin, DL; Noble, RD

    2015-04-29

    New imidazolium- and pyrrolidinium-based bis(epoxide)-functionalized ionic liquid (IL) monorners were synthesized: and reacted with multifunctional amine monomers to produce cross-linked, epoxy-amine poly(ionic liquid) (PIL) resins and PIL/IL ion-gel membranes. The length and chemical nature (i.e., alkyl versus ether) between the irrildazolium group and epokitie groups were studied to determine their effects on CO2 affinity. The CO2 uptake (millimoles per gram) of the epoxy amine resins (between 0.1 and 1 mmol/g) was found to depend predominately on the epoxide-to-amine ratio and the bis(epoxide) IL molecular weight. The effect of using a primary versus a secondary amine-containing multifunctional monoiner was also assessed for the resin-synthesis. Secondary amines can increase CO2 permeability but also increase the iime required for biS(epoxide) coriversion. When either the epoxide or athine monomer structure is changed, the CO2 solubility and permeability of the resulting PIL resins and ion-sel membranes can be tuned.

  10. Multifunctional Iodide-Free Polymeric Ionic Liquid for Quasi-Solid-State Dye-Sensitized Solar Cells with a High Open-Circuit Voltage.

    Science.gov (United States)

    Lin, Yi-Feng; Li, Chun-Ting; Lee, Chuan-Pei; Leu, Yow-An; Ezhumalai, Yamuna; Vittal, R; Chen, Ming-Chou; Lin, Jiang-Jen; Ho, Kuo-Chuan

    2016-06-22

    A polymeric ionic liquid, poly(oxyethylene)-imide-imidazolium selenocyanate (POEI-IS), was newly synthesized and used for a multifunctional gel electrolyte in a quasi-solid-state dye-sensitized solar cell (QSS-DSSC). POEI-IS has several functions: (a) acts as a gelling agent for the electrolyte of the DSSC, (b) possesses a redox mediator of SeCN(-), which is aimed to form a SeCN(-)/(SeCN)3(-) redox couple with a more positive redox potential than that of traditional I(-)/I3(-), (c) chelates the potassium cations through the lone pair electrons of the oxygen atoms of its poly(oxyethylene)-imide-imidazolium (POEI-I) segments, and (d) obstructs the recombination of photoinjected electrons with (SeCN)3(-) ions in the electrolyte through its POEI-I segments. Thus, the POEI-IS renders a high open-circuit voltage (VOC) to the QSS-DSSC due to its functions of b-d and prolongs the stability of the cell due to its function of a. The QSS-DSSC with the gel electrolyte containing 30 wt % of the POEI-IS in liquid selenocyanate electrolyte exhibited a high VOC of 825.50 ± 3.51 mV and a high power conversion efficiency (η) of 8.18 ± 0.02%. The QSS-DSSC with 30 wt % POEI-IS retained up to 95% of its initial η after an at-rest stability test with the period of more than 1,000 h.

  11. Ionic hydrogenation of organosulfur compounds

    Energy Technology Data Exchange (ETDEWEB)

    Eckert-Maksic, M.; Margetic, D. (Rudjer Boskovic Institute, Zagreb (Yugoslavia). Dept. of Organic Chemistry and Biochemistry)

    Ionic hydrogenation of the three most abundant types of organosulfur constituents of coal, aromatic sulfides, aromatic disulfides, and benzo(b)thiophene derivatives, in BF{sub 3}.H{sub 2}O-Et{sub 3}SiH is studied. Reduction of aromatic sulfides results in partial saturation of the aromatic moiety and cleavage of the corresponding SR group. Aromatic disulfides undergo quantitative sulfur-sulfur bond cleavage, while benzo(b)thiophene derivatives produce 2,3-dihydrobenzo(b)thiophenes in high yields. 32 refs., 2 figs., 3 tabs.

  12. Electrochemical Behavior of PEDOT/Lignin in Ionic Liquid Electrolytes: Suitable Cathode/Electrolyte System for Sodium Batteries.

    Science.gov (United States)

    Casado, Nerea; Hilder, Matthias; Pozo-Gonzalo, Cristina; Forsyth, Maria; Mecerreyes, David

    2017-04-22

    Biomass-derived polymers, such as lignin, contain quinone/ hydroquinone redox moieties that can be used to store charge. Composites based on the biopolymer lignin and several conjugated polymers have shown good charge-storage properties. However, their performance has been only studied in acidic aqueous media limiting their applications mainly to supercapacitors. Here, we show that PEDOT/lignin (PEDOT: poly(3,4-ethylenedioxythiophene)) biopolymers are electroactive in aprotic ionic liquids (ILs) and we move a step further by assembling sodium full cell batteries using PEDOT/lignin as electrode material and IL electrolytes. Thus, the electrochemical activity and cycling of PEDOT/lignin electrodes was investigated in 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BMPyrTFSI), 1-butyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide (BMPyrFSI), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMImTFSI) and 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMImFSI) IL electrolytes. The effects of water and sodium salt addition to the ILs were investigated to obtain optimum electrolyte systems for sodium batteries. Finally, sodium batteries based on PEDOT/lignin cathode with imidazolium-based IL electrolyte showed higher capacity values than pyrrolidinium ones, reaching 70 mAhg-1 . Our results demonstrate that PEDOT/lignin composites can serve as low cost and sustainable cathode materials for sodium batteries. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Effect of Side Chain Functional Group on Interactions in Ionic Liquid Systems: Insights from Infinite Dilution Thermodynamic Data.

    Science.gov (United States)

    Paduszyński, Kamil; Królikowska, Marta

    2017-11-02

    Measurements of infinite dilution activity coefficients of 48 molecular solutes (including alkanes, alkenes, alkynes, aromatics, ethers, alcohols, water, ketones, pyridine, thiophene, acetonitrile, and 1-nitropropane) in two ionic liquids (ILs), namely, 1-(2-hydroxyethyl)-3-methylimidazolium dicyanamide and 1-(2-chloroethyl)-3-methylimidazolium dicyanamide, are reported in the temperature range from T = 308.15 to 358.15 K. Comparative analysis of an effect of OH/Cl substitution of terminal carbon in side chains of imidazolium cations is presented and discussed in terms of different types of intermolecular forces acting between ILs and solutes. The new data also are confronted to those published previously for a "plain" counterpart of the studied ILs, namely, 1-ethyl-3-methylimidazolium dicyanamide. Infinite dilution capacity and selectivity of the studied ILs are presented to evaluate them as separating agents in extraction of aromatics from alkanes and sulfur compounds from alkanes. Three modeling approaches, namely, linear solvation energy relationship (LSER), regular solution theory, and conductor-like screening model for real solvents (COSMO-RS), are tested for their capabilities of capturing the substitution effects detected experimentally.

  14. Extraction separation of rare-earth ions via competitive ligand complexations between aqueous and ionic-liquid phases.

    Science.gov (United States)

    Sun, Xiaoqi; Bell, Jason R; Luo, Huimin; Dai, Sheng

    2011-08-21

    The extraction separation of rare earth elements is one of the most challenging separation processes in hydrometallurgy and advanced nuclear fuel cycles. The TALSPEAK process (trivalent actinide lanthanide separations by phosphorus-reagent extraction from aqueous komplexes) is a prime example of these separation processes. The objective of this paper is to explore the use of ionic liquids (ILs) for the TALSPEAK-like process, to further enhance its extraction efficiencies for lanthanides, and to investigate the potential of using this modified TALSPEAK process for separation of lanthanides among themselves. Eight imidazolium ILs ([C(n)mim][NTf(2)] and [C(n)mim][BETI], n = 4,6,8,10) and one pyrrolidinium IL ([C(4)mPy][NTf(2)]) were investigated as diluents using di(2-ethylhexyl)phosphoric acid (HDEHP) as an extractant for the separation of lanthanide ions from aqueous solutions of 50 mM glycolic acid or citric acid and 5 mM diethylenetriamine pentaacetic acid (DTPA). The extraction efficiencies were studied in comparison with diisopropylbenzene (DIPB), an organic solvent used as a diluent for the conventional TALSPEAK extraction system. Excellent extraction efficiencies and selectivities were found for a number of lanthanide ions using HDEHP as an extractant in these ILs. The effects of different alkyl chain lengths in the cations of ILs and of different anions on extraction efficiencies and selectivities of lanthanide ions are also presented in this paper. This journal is © The Royal Society of Chemistry 2011

  15. Automated evaluation of pharmaceutically active ionic liquids’ (eco)toxicity through the inhibition of human carboxylesterase and Vibrio fischeri

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Susana P.F.; Justina, Vanessa D. [REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, n° 228, 4050-313 Porto (Portugal); Bica, Katharina; Vasiloiu, Maria [Vienna University of Technology, Institute of Applied and Synthetic Chemistry, A-1060 Vienna (Austria); Pinto, Paula C.A.G., E-mail: ppinto@ff.up.pt [REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, n° 228, 4050-313 Porto (Portugal); Saraiva, M. Lúcia M.F.S., E-mail: lsaraiva@ff.up.pt [REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, n° 228, 4050-313 Porto (Portugal)

    2014-01-30

    Highlights: • IL-APIs toxicity on humans and aquatic environment was evaluated by inhibition assays. • The inhibition assays were implemented through automated screening bioassays. • Automation of bioassays enabled a rigorous control of the reaction conditions. • EC{sub 50} obtained provide vital information on IL-APIs safety and potential use as drugs. -- Abstract: The toxicity of 16 pharmaceutical active ionic liquids (IL-APIs) was evaluated by automated approaches based on sequential injection analysis (SIA). The implemented bioassays were centered on the inhibition of human carboxylesterase 2 and Vibrio fischeri, in the presence of the tested compounds. The inhibitory effects were quantified by calculating the inhibitor concentration required to cause 50% of inhibition (EC{sub 50}). The EC{sub 50} values demonstrated that the cetylpyridinium group was one of the most toxic cations and that the imidazolium group was the less toxic. The obtained results provide important information about the safety of the studied IL-APIs and their possible use as pharmaceutical drugs. The developed automated SIA methodologies are robust screening bioassays, and can be used as a generic tools to identify the (eco)toxicity of the structural elements of ILs, contributing to a sustainable development of drugs.

  16. The acute toxic effects of 1-alkyl-3-methylimidazolium nitrate ionic liquids on Chlorella vulgaris and Daphnia magna.

    Science.gov (United States)

    Zhang, Cheng; Zhang, Shuai; Zhu, Lusheng; Wang, Jinhua; Wang, Jun; Zhou, Tongtong

    2017-10-01

    Given their increasingly widespread application, the toxic effects of ionic liquids (ILs) have become the subject of significant attention in recent years. Therefore, the present study assessed the acute toxic effects of 1-alkyl-3-methylimidazolium nitrate ([Cnmim]NO3 (n = 2, 4, 6, 8, 10, 12)) on Chlorella vulgaris and Daphnia magna. The sensitivity of the tested organism Daphnia magna and the investigated IL concentrations in water using high-performance liquid chromatography (HPLC) were also evaluated to demonstrate the reliability of the present study. The results illustrated that Daphnia magna is indeed sensitive to the reference toxicant and the investigated ILs were stable in the aquatic environment. The 50% effect concentration (EC50) was used to represent the acute toxic effects on Chlorella vulgaris and Daphnia magna. With the increasing alkyl-chain lengths, the toxicity of the investigated ILs increased in both the test organisms. Accordingly, the alkyl-chain lengths can cause significantly toxic effects on aquatic organisms, and Daphnia magna are much more sensitive than Chlorella vulgaris to the imidazolium-based ILs used in the present study. Furthermore, the present study provides more information on the acute toxic effects of 1-alkyl-3-methylimidazolium nitrate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. 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)

  18. Deep desulfurization by amphiphilic lanthanide-containing polyoxometalates in ionic-liquid emulsion systems under mild conditions.

    Science.gov (United States)

    Xu, Junhua; Zhao, Shen; Ji, Yuanchun; Song, Yu-Fei

    2013-01-07

    Amphiphilic lanthanide-containing polyoxometalates (POMs) were prepared by surfactant encapsulation. Investigation of these lanthanide-containing POMs in oxidative desulfurization (ODS) showed that highly efficient deep desulfurization could be achieved in only 14 min with 100% conversion of dibenzothiophene under mild conditions by using (DDA)(9)LaW(10)/[omim]PF(6) (DDA=dimethyldioctadecylammonium, omim=1-octyl-3-methyl-imidazolium) in the presence of H(2) O(2) . Furthermore, deep desulfurization proceeds smoothly in model oil with an S content as low as 50 ppm. A scaled-up experiment in which the volume of model oil was increased from 5 to 1000 mL with S content of 1000 ppm indicated that about 99% sulfur removal can be achieved in 40 mins in an ionic-liquid emulsion system. To the best of our knowledge, the (DDA)(9)LaW(10)/[omim]PF(6) catalyst system with H(2)O(2) as oxidant is one of the most efficient desulfurization systems reported so far. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Preparation of Thermo-Responsive Poly(ionic liquids-Based Nanogels via One-Step Cross-Linking Copolymerization

    Directory of Open Access Journals (Sweden)

    Jing Zhang

    2015-09-01

    Full Text Available In this study, thermo-responsive polymeric nanogels were facilely prepared via one-step cross-linking copolymerization of ethylene glycol dimethacrylate/divinylbenzene and ionic liquid (IL-based monomers, 1,n-dialkyl-3,3′-bis-1-vinyl imidazolium bromides ([CnVIm]Br; n = 6, 8, 12 in selective solvents. The results revealed that stable and blue opalescent biimidazolium (BIm-based nanogel solutions could be obtained without any precipitation when the copolymerizations were conducted in methanol. Most importantly, these novel nanogels were thermo-response, and could reversibly transform to precipitation in methanol with temperature changes. Turbidity analysis and dynamic light scatting (DLS measurement illustrated that PIL-based nanogel solutions presented the phase transform with upper critical solution temperature (UCST in the range of 5–25 °C. The nanogels were characterized using Fourier transform infrared (FTIR, thermogravimetric analyses (TGA, and scanning electron microscopy (SEM. In addition, BIm-based nanogels could also be used as highly active catalysts in the cycloaddition reaction of CO2 and epoxides. As a result, our attributes build a robust platform suitable for the preparation of polymeric nanomaterials, as well as CO2 conversion.

  20. Nonaqueous System of Iron-Based Ionic Liquid and DMF for the Oxidation of Hydrogen Sulfide and Regeneration by Electrolysis.

    Science.gov (United States)

    Guo, Zhihui; Zhang, Tingting; Liu, Tiantian; Du, Jun; Jia, Bing; Gao, Shujing; Yu, Jiang

    2015-05-05

    To improve the hydrogen sulfide removal efficiency with the application of an iron-based imidazolium chloride ionic liquid (Fe(III)-IL) as desulfurizer, Fe(II) and N,N-dimethylformamide (DMF) are introduced to Fe(III)-IL to construct a new nonaqueous desulfurization system (Fe(III/II)-IL/DMF). Following desulfurization, the system can be regenerated using the controlled-potential electrolysis method. The addition of Fe(II) in Fe(III)-IL is beneficial for the hydrogen sulfide removal and the electrochemical regeneration of the desulfurizer. The addition of DMF in Fe(III/II)-IL does not change the structure of Fe(III/II)-IL but clearly decreases the acidity, increases the electrolytic current, and decreases the stability of the Fe-Cl bond in Fe(III/II)-IL. Fe(III/II)-IL/DMF can remove hydrogen sulfide and can be regenerated through an electrochemical method more efficiently than can Fe(III/II)-IL. After six cycles, the desulfurization efficiency remains higher than 98%, and the average conversion rate of Fe(II) is essentially unchanged. No sulfur peroxidation occurs, and the system remains stable. Therefore, this new nonaqueous system has considerable potential for removing H2S in pollution control applications.

  1. Membrane partitioning of ionic liquid cations, anions and ion pairs - Estimating the bioconcentration potential of organic ions.

    Science.gov (United States)

    Dołżonek, Joanna; Cho, Chul-Woong; Stepnowski, Piotr; Markiewicz, Marta; Thöming, Jorg; Stolte, Stefan

    2017-09-01

    Recent efforts have been directed towards better understanding the persistency and toxicity of ionic liquids (ILs) in the context of the "benign-by-design" approach, but the assessment of their bioaccumulation potential remains neglected. This paper reports the experimental membrane partitioning of IL cations (imidazolium, pyridinium, pyrrolidinium, phosphonium), anions ([C(CN)3](-), [B(CN)4](-), [FSO2)2N](-), [(C2F5)3PF3](-), [(CF3SO2)2N](-)) and their combinations as a measure for estimating the bioconcentration factor (BCF). Both cations and anions can have a strong affinity for phosphatidylcholine bilayers, which is mainly driven by the hydrophobicity of the ions. This affinity is often reflected in the ecotoxicological impact. Our data revealed that the bioconcentration potential of IL cations and anions is much higher than expected from octanol-water-partitioning based estimations that have recently been presented. For some ILs, the membrane-water partition coefficient reached levels corresponding to BCFs that might become relevant in terms of the "B" (bioaccumulation potential) classification under REACH. However, this preliminary estimation need to be confirmed by in vivo bioconcentration studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. 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

  3. 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

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  8. Comparison of intravenous drip infusion excretory urography using ionic and non-ionic contrast media

    Energy Technology Data Exchange (ETDEWEB)

    Onitsuka, Hideo; Araki, Akiteru; Torii, Yoshikuni; Tsukuda, Masaaki; Murakami, Junji; Ino, Akihiro; Hashiguchi, Norihisa; Masuda, Kouji (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

    1989-07-01

    Ionic and non-ionic contrast media were compared for use in intravenous drip infusion excretory urography. Sixty consecutive cases were classified alternately into two groups, ionic and non-ionic, excluding cases which were known to have factors affecting contrast ability adversely, such as hydronephrosis, renal failure and so on. Each group consisted of 30 cases. A hundred ml of the ionic contrast medium (Diatrizoate-60% Urografin) or non-ionic contrast medium (Iopamidol-Iopamiron 300) was administered I.V. by drip infusion, each infusion taking less than 10 minutes, using a 18 G needle, and 0-minute, 10-minute and 20-minute films were obtained. Visibility of nephrogram, calyceal system, renal pelvis, ureters and bladder were evaluated, ranging from 0 to 3, by six radiologists who were not informed of the contrast medium used. Some detailed factors such as radiographic contrast and fullness of the collecting system and of the bladder were also analyzed. Visualization rate of the ureters was defined as the length of visualized ureters divided by the distance between the renal pelvis and the ureteral orifice of the bladder. There was no significant difference in visualization of nephrogram between the two groups. However, the non-ionic group was superior to the ionic group in visualization of the calyceal system and ureters with statistical significance, probably due to higher radiogrpahic contrast of non-ionic medium. There was no statistical significance between the two groups, in fullness of the calyceal system and visualization rate of the ureters, whereas the ionic group was superior to the non-ionic group in fullness of the bladder. In the ionic and non-ionic groups, side effects were seen in 6 and 2 cases, respectively, although this was not statistically significant. We conclude that non-ionic contrast medium is excellent for drip infusion excretory urography. (author).

  9. Ionic liquid templated porous nano-TiO2 particles for the selective isolation of cytochrome c.

    Science.gov (United States)

    Meng, Hao; Chen, Xu-Wei; Wang, Jian-Hua

    2010-09-24

    Porous nano-titanium dioxide (TiO(2)) particles with anatase framework were prepared by using an effective template of hydrophobic ionic liquid, i.e., N, N-bis [2-methylbutyl] imidazolium hexafluorophosphate ([PPim][PF(6)]). The nano-TiO(2) particles were characterized with TEM and BET, resulting in the distribution of the pore diameters centering at 7.3 nm and 26.2 nm, attributed to the template effect of the ionic liquid and the aggregation of the TiO(2) particles, respectively. A much improved surface area of 68.31 m(2) g(-1) and a pore volume of 0.2814 cm(3) g(-1) were obtained with respect to 15.16 m(2) g(-1) and 0.0402 cm(3) g(-1) achieved by the non-templated nano-TiO(2) counterpart. The porous nano-TiO(2) particles were used as adsorbent for selective adsorption and isolation of cytochrome c (cyt-c) at certain conditions. An adsorption efficiency of 87% was achieved for 150 microg ml(-1) cyt-c in 1.0 ml of sample solution at pH 9.0 by using 2.0 mg of the nano-TiO(2) particles, in comparison to 30% obtained by the non-templated nano-TiO(2). In addition, an adsorption capacity of 112.6 microg mg(-1) was derived for the porous nano-TiO(2) with respect to 25.1 microg mg(-1) for the normal ones. The absorbed cyt-c could be readily recovered by stripping with a 0.1 mol l(-1) Na(3)PO(4) solution, giving rise to a recovery of ca. 90%. The porous nano-TiO(2) particles have been used for the isolation of cyt-c from human whole blood, achieving satisfactory results by assay with SDS-PAGE.

  10. Applications of ionic liquids in carbohydrate chemistry: a window of opportunities.

    Science.gov (United States)

    El Seoud, Omar A; Koschella, Andreas; Fidale, Ludmila C; Dorn, Susann; Heinze, Thomas

    2007-09-01

    Ionic liquids (ILs) are composed only of ions. Of special interest to this review are those where at least one ion (the cation) is organic and whose melting points are below or not far above room temperature. ILs are designated as "green" solvents because they have extremely low vapor pressure, are non-inflammable, and thermally and chemically stable. Therefore, many of them can be, in principle, recycled into the process indefinitely. The objective of the present review is to discuss different aspects of the use of ILs in carbohydrate chemistry, in particular, dissolution and functionalization of simple sugars, cyclodextrins, cellulose, starch, and chitin/chitosan. The molecular structure and synthesis of ILs most frequently employed in carbohydrate chemistry are discussed with an emphasis on imidazolium and pyridinium cations with different counterions. The physicochemical properties of ILs that are relevant to the dissolution and functionalization of carbohydrates, in particular their polarities and hydrogen-bonding abilities, are discussed. Dissolution of simple saccharides and biopolymers in ILs is presented with an emphasis on the mechanism of carbohydrate--IL interactions. Finally, the very interesting novel applications of the solutions obtained are addressed. These include, inter alia, spinning of the dissolved biopolymer into fibers, extrusion into slabs and rods, formation of matrixes for a myriad of substrates, including biomacromolecules, formation of nanocomposites, and functionalization to produce important derivatives. The use of ILs in many branches of science is expanding fast; it is hoped that this review will draw the attention of researchers to the "window of opportunities" that these green solvents open into carbohydrate chemistry.

  11. Anion and cation dynamics of sulfonylamide-based ionic liquids and the solid-liquid transitions.

    Science.gov (United States)

    Imanari, Mamoru; Fujii, Kozo; Mukai, Tomohiro; Mizushima, Noriko; Seki, Hiroko; Nishikawa, Keiko

    2015-04-14

    Some of the important factors that characterise room-temperature ionic liquids (RTILs) are the variety of conformations adopted by the constituent ions and their flexibility. Using 1,3-dimethylimidazolium bis(fluorosulfonyl)amide ([C1mim][FSA]) and 1,3-dimethylimidazolium bis(trifluoromethylsulfonyl)amide ([C1mim][NTf2]) as samples, the longitudinal and transverse relaxation times (T1 and T2) for (19)F and (1)H were determined as a function of temperature and were correlated with the dynamics of the phase behaviours of the two RTILs. Because the anions and cations in the two compounds have (19)F and (1)H nuclei, respectively, their dynamics can be independently investigated and the relationships between them can be discussed. For [C1mim][FSA], the only observed phase changes included melting and crystallisation. The temperature dependences of T1 and T2 for (19)F were similar to those of T1 and T2 for (1)H, indicating similar dynamics due to the formation of strong anion-cation interactions. For [C1mim][NTf2], the T1 and T2 values for both (19)F and (1)H discontinuously changed at same temperatures, which were assigned to the crystallisation and melting points. However, the T1 curves for (19)F and (1)H were different in the crystalline region, suggesting independent dynamics for the anions and cations in [C1mim][NTf2]. In the crystalline state for each salt, the cation dynamics was distinctly separated into the framework movement of the imidazolium ring and the movement of the methyl groups, while the anion dynamics was characterised by the movement of the entire anion. The influence of the crystal structure on the dynamics of each salt was also considered.

  12. Ionic liquid-assisted synthesis of highly dispersive bowknot-like ZnO microrods for photocatalytic applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Shuo [School of Chemistry and Chemical Engineering, Southeast University, Jiangsu Optoelectronic Functional Materials and Engineering Laboratory, Nanjing 211189 (China); Zhang, Yiwei, E-mail: zhangchem@seu.edu.cn [School of Chemistry and Chemical Engineering, Southeast University, Jiangsu Optoelectronic Functional Materials and Engineering Laboratory, Nanjing 211189 (China); Zhou, Yuming, E-mail: ymzhou@seu.edu.cn [School of Chemistry and Chemical Engineering, Southeast University, Jiangsu Optoelectronic Functional Materials and Engineering Laboratory, Nanjing 211189 (China); Zhang, Chao; Sheng, Xiaoli; Fang, Jiasheng; Zhang, Mingyu [School of Chemistry and Chemical Engineering, Southeast University, Jiangsu Optoelectronic Functional Materials and Engineering Laboratory, Nanjing 211189 (China); Yang, Yong [School of Chemical Engineering, Nanjing University of Science and Technology, 200 Xiao Ling Wei St, Nanjing 210094, Jiangsu (China)

    2017-04-01

    Highlights: • Ionic liquid was used as template for dispersive bowknot-like ZnO microrods. • The bowknot-like ZnO consists of individual microrods whose size is about 1 μm. • The formation mechanism of the ZnO materials is tentatively elucidated. • The bowknot-like ZnO exhibited the high catalytic activity in the photodegradation. • Photocatalytic activity is a result of the combination of various factors. - Abstract: Here we present a facile method for the preparation of highly dispersive ZnO materials by using ionic liquid 1-methyl-3-[3′-(trimethoxysilyl) propyl] imidazolium chloride as the template. The influence of ionic liquid concentration and calcined atmosphere on the photoactivity is studied. The samples were characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), scanning electron microscope (SEM), N{sub 2} gas sorption and ultraviolet-visible diffuse reflectance spectroscopy. The results showed that the as-fabricated ZnO materials consisted of individual microrods with self-assembled bowknot-like architecture whose size was about 1 μm. The formation mechanism of the bowknot-like ZnO materials which is based on the self-assembly of ionic liquid is tentatively elucidated. Moreover, the ZnO-2.6N sample exhibited the higher activity for the photodegradation of MB than the photodegradation of MO and RhB. Furthermore, it was found that the ZnO materials calcined under air atmosphere showed the better photocatalytic activities than that of samples calcined under nitrogen atmosphere in the degradation of methylene blue (MB) under UV irradiation. And the special structure, surface area, adsorption capability of dye, the separation rate of photogenerated electron–hole pairs and band gap had effects on the photocatalytic activity of ZnO photocatalysts. O{sub 2}·{sup −} was the main active species for the photocatalytic degradation of MB. It is valuable to develop this facile

  13. Understanding the Effect of Solvent Structure on Organic Reaction Outcomes When Using Ionic Liquid/Acetonitrile Mixtures.

    Science.gov (United States)

    Keaveney, Sinead T; Greaves, Tamar L; Kennedy, Danielle F; Harper, Jason B

    2016-12-15

    The rate constant for the reaction between hexan-1-amine and 4-methoxybenzaldehyde was determined in ionic liquids containing an imidazolium cation. The effect on the rate constant of increasing the length of the alkyl substituent on the cation was examined in a number of ionic liquid/acetonitrile mixtures. In general it was found that there was no significant effect of changing the alkyl substituent on the rate constant of this process, suggesting that any nanodomains in these mixtures do not have a significant effect on the outcome of this process. A series of small-angle X-ray scattering and wide-angle X-ray scattering experiments were performed on mixtures of the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([Bmim][N(CF3SO2)2]) and acetonitrile; this work indicated that the main structural changes in the mixtures occur by about a 0.2 mole fraction of ionic liquid in the mixture (χIL). This region at which the main changes in the solvent structuring occurs corresponds to the region at which the main changes in the rate constant and activation parameters occur for SN2 and condensation reactions examined previously; this is the first time that such a correlation has been observed. To examine the ordering of the solvent about the nucleophile hexan-1-amine, WAXS experiments were performed on a number of [Bmim][N(CF3SO2)2]/acetonitrile/hexan-1-amine mixtures, where it was found that some of the patterns featured asymmetric peaks as well as additional peaks not observed in the [Bmim][N(CF3SO2)2]/acetonitrile mixtures; this suggests that the addition of hexan-1-amine to the mixture affects the bulk structure of the liquid. The SAXS/WAXS patterns of mixtures of 1-butyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide ([Bm2im][N(CF3SO2)2]) and acetonitrile were also determined, with the results suggesting that [Bm2im][N(CF3SO2)2] is more ordered than [Bmim][N(CF3SO2)2] due to an enhancement in the short-range interactions.

  14. Facile one-pot preparation of a novel imidazolium-based monolith by thiol-ene click chemistry for capillary liquid chromatography.

    Science.gov (United States)

    Zhang, Peng; Yang, Haiguan; Chen, Tao; Qin, Yuemei; Ye, Fanggui

    2017-11-01

    In this work, a novel imidazolium-based monolith was fabricated through a simple route. With 1-vinyl-3-octadecylimidazolium bromide and ethylene dimethacrylate as monomers, pentaerythritol tetra-(3-mercaptopropionate) as crosslinker, AIBN as thermal initiator, the monolith was facilely fabricated by one-pot thiol-ene click chemistry. The influences of both the content of monomer/crosslinker and porogenic systems on the morphology, and permeability of the monolith were studied. The optimal reaction conditions were used to prepare a homogeneous and permeable monolith. The optimal preparation of monolithic column was characterized by scanning electron microscopy, Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy, and thermogravimetric analysis. High efficiency and quick separation of alkylbenzenes, styrene and ethylbenzene, polycyclic aromatic hydrocarbon, phenols, anilines, and aromatic acids were achieved. The minimum plate height of this monolith were determined as 11.42 μm for thiourea and 13.26 μm for benzene. All results indicated that thiol-ene click chemistry provides a quick way for the fabrication of imidazolium-based monolith. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. CADDIS Volume 2. Sources, Stressors and Responses: Ionic Strength - Simple Conceptual Diagram

    Science.gov (United States)

    Introduction to the ionic strength module, when to list ionic strength as a candidate cause, ways to measure ionic strength, simple and detailed conceptual diagrams for ionic strength, ionic strength module references and literature reviews.

  16. CADDIS Volume 2. Sources, Stressors and Responses: Ionic Strength - Detailed Conceptual Diagram

    Science.gov (United States)

    Introduction to the ionic strength module, when to list ionic strength as a candidate cause, ways to measure ionic strength, simple and detailed conceptual diagrams for ionic strength, ionic strength module references and literature reviews.

  17. Infrared spectroscopy of ionic clusters

    Energy Technology Data Exchange (ETDEWEB)

    Price, J.M. (California Univ., Berkeley, CA (USA). Dept. of Chemistry Lawrence Berkeley Lab., CA (USA))

    1990-11-01

    This thesis describes new experiments wherein the infrared vibrational predissociation spectra of a number of mass-selected ionic cluster systems have been obtained and analyzed in the 2600 to 4000 cm{sup {minus}1} region. The species studied include: the hydrated hydronium ions, H{sub 3}O{sup +} (H{sub 2}O){sub 3 {minus}10}, ammoniated ammonium ions, NH{sub 4}{sup +}(NH{sub 3}){sub 1 {minus}10} and cluster ions involving both water and ammonia around an ammonium ion core, (mixed clusters) NH{sub 4}{sup +}(NH{sub 3}){sub n}(H{sub 2}O){sub m} (n+m=4). In each case, the spectra reveal well resolved structures that can be assigned to transitions arising from the vibrational motions of both the ion core of the clusters and the surrounding neutral solvent molecules. 154 refs., 19 figs., 8 tabs.

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

    National Research Council Canada - National Science Library

    Berretti, Enrico; Giaccherini, Andrea; Martinuzzi, Stefano; Innocenti, Massimo; Schubert, Thomas; Stiemke, Frank; Caporali, Stefano

    2016-01-01

    .... 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...

  19. [Synthesis and action of 1-n-hexyl-2-phenyl-3-(n-alkoxymethyl)- and 1-n-hexyl-2-phenyl-3-(6-n-alkylthiomethyl)imidazolium chlorides].

    Science.gov (United States)

    Pernak, J; Skrzypczak, A; Michalak, L; Krysiński, J; Peterko, B

    1990-09-01

    The synthesis of quaternary imidazolium chlorides was performed by reaction of 1-n-hexyl-2-phenyl-imidazole with chloromethylalkyl ether or chlormethylalkyl sulfide. The antibacterial properties of the compounds obtained was tested on 13 strains of bacteria and fungi. Chlorides with octyl- and decylthiomethyl moiety indicated the best antibacterial activity.

  20. 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.

  1. Grafting chitosan with polyethylenimine in an ionic liquid for efficient gene delivery.

    Science.gov (United States)

    Chen, Huiying; Cui, Shaohui; Zhao, Yinan; Zhang, Chuanmin; Zhang, Shubiao; Peng, Xiaojun

    2015-01-01

    Modifying chitosan (CS) with polyethylenimine (PEI) grafts is an effective way to improve its gene transfection performance. However, it is still a challenge to conduct the grafting with fine control and high efficiency, particularly for the modification of water-insoluble CS. Herein, a novel method to graft CS with PEI (1.8 kDa, PEI-1.8) was developed by using ionic liquid 1-butyl-3-methyl imidazolium acetate ([BMIM]Ac) as a reaction solvent, water-insoluble CS as a reaction substrate and 1,1-carbonyldiimidazole (CDI) as a linking agent. The grafting reaction was greatly accelerated and the reaction time was largely shortened to 4 h by taking advantages of the good solubility of CS, the enhanced nucleophilicity of amino groups and the preferential stability of the activated complexes in the ionic liquid. The chitosan-graft-polyethylenimine (CS-g-PEI) products were characterized by 1H NMR, FTIR and GPC. PEI-1.8 was quantitatively grafted to CS through urea linkages, and the grafting degree (GD) was conveniently tuned by varying the molar ratios of PEI-1.8 to D-glucosamine units of CS in the range of 9.0 × 10(-3) to 9.0 × 10(-2). Compared with CS, the synthesized CS-g-PEI copolymers showed higher pDNA-binding affinity, which increased with the GD as shown in Agarose gel electrophoresis. The dynamic light scattering (DLS) experiment demonstrated that the CS-g-PEI/pDNA polyplexes had suitable particle sizes and proper ζ-potentials for cell transfection. The CS-g-PEI copolymer with a medium GD of 4.5% conferred the best gene transfection, with the efficiency 44 times of CS and 38 times of PEI-1.8 in HEp-2 cells. The cytotoxicity of CS-g-PEI was tested and found nearly as low as that of CS and much lower than that of PEI.

  2. 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.

  3. 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.

  4. Synthesis of hetero ionic compounds using dialkylcarbonate quaternization

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-09-19

    Methods of preparing hetero ionic complexes, and ionic liquids from bisulfate salts of heteroatomic compounds using dialkylcarbonates as a primary quaternizing reactant are disclosed. Also disclosed are methods of making electrochemical cells comprising the ionic liquids, and an electrochemical cell comprising an alkaline electrolyte and a hetero ionic complex additive.

  5. 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...

  6. 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.

  7. A silica nanoparticle based ionic material

    Science.gov (United States)

    Fernandes, Nikhil; Azad, Zubair; Giannelis, Emmanuel

    2011-03-01

    We report an ionic fluid consisting of silica nanoparticles as the anion, and amine-terminated polyethylene glycol as the cation. Unlike previous work that has required chemical functionalization of the silica surface, the charge on the nanoparticle anion is carried by the intrinsic surface hydroxyls, simplifying the synthesis, and thus making this a simple test system to probe the physics of these nanoscale ionic materials. Charge and steric factors result in excellent dispersion of the nanoparticles in the polymer matrix. The resulting material is a soft glass that has thermal and rheological properties that depend on the silica:polymer ratio. In particular, at a critical silica:polymer ratio, the ionic material shows a significant depression of the normalized heat of melting and the melting temperature compared to samples with higher or lower silica content (showing eutectic-like behaviour), and to controls without the ionic interaction between the polymer and the particle. Funded by KAUST-CU.

  8. 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.

  9. 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...

  10. 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.

  11. 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.

  12. 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...

  13. 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.

  14. 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.

  15. 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...

  16. Green Hypergolic Bipropellants: H202/Hydrogen-Rich Ionic Liquids

    Science.gov (United States)

    2011-03-04

    unsaturated salts featuring imidazolium, triazolium, pyridinium and other common IL cations, are reduced by BH4-,[6] negatively affecting their thermal...trihexyl-tetradecyl- phosphonium (THTDP) cation has been used to transform fullerenes into RTILs and forms liquids with BH3Cl-.[12, 13] THTDP Cl is also...can lead to serious injuries! General. Starting materials, trihexyltetradecyl- phosphonium chloride, sodium borohydride (≥99%), lithium borohydride

  17. 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.

  18. 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, ...

  19. N,N’-alkylated Imidazolium-Derivatives Act as Quorum-Sensing Inhibitors Targeting the Pectobacterium atrosepticum-Induced Symptoms on Potato Tubers

    Directory of Open Access Journals (Sweden)

    Valérie Hélias

    2013-10-01

    Full Text Available Bacteria belonging to the Pectobacterium genus are the causative agents of the blackleg and soft-rot diseases that affect potato plants and tubers worldwide. In Pectobacterium, the expression of the virulence genes is controlled by quorum-sensing (QS and N-acylhomoserine lactones (AHLs. In this work, we screened a chemical library of QS-inhibitors (QSIs and AHL-analogs to find novel QSIs targeting the virulence of Pectobacterium. Four N,N’-bisalkylated imidazolium salts were identified as QSIs; they were active at the µM range. In potato tuber assays, two of them were able to decrease the severity of the symptoms provoked by P. atrosepticum. This work extends the range of the QSIs acting on the Pectobacterium-induced soft-rot disease.

  20. N,N′-alkylated Imidazolium-Derivatives Act as Quorum-Sensing Inhibitors Targeting the Pectobacterium atrosepticum-Induced Symptoms on Potato Tubers

    Science.gov (United States)

    des Essarts, Yannick Raoul; Sabbah, Mohamad; Comte, Arnaud; Soulère, Laurent; Queneau, Yves; Dessaux, Yves; Hélias, Valérie; Faure, Denis

    2013-01-01

    Bacteria belonging to the Pectobacterium genus are the causative agents of the blackleg and soft-rot diseases that affect potato plants and tubers worldwide. In Pectobacterium, the expression of the virulence genes is controlled by quorum-sensing (QS) and N-acylhomoserine lactones (AHLs). In this work, we screened a chemical library of QS-inhibitors (QSIs) and AHL-analogs to find novel QSIs targeting the virulence of Pectobacterium. Four N,N′-bisalkylated imidazolium salts were identified as QSIs; they were active at the μM range. In potato tuber assays, two of them were able to decrease the severity of the symptoms provoked by P. atrosepticum. This work extends the range of the QSIs acting on the Pectobacterium-induced soft-rot disease. PMID:24108370