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Sample records for liquid 1-ethyl-3-methylimidazolium trifluoromethanesulfonate

  1. Molecular Structure and Interactions in the Ionic Liquid 1-Ethyl-3-methylimidazolium Trifluoromethanesulfonate.

    PubMed

    Singh, Dheeraj K; Rathke, Bernd; Kiefer, Johannes; Materny, Arnulf

    2016-08-11

    Quantum chemical theory (DFT and MP2) and vibrational spectroscopy (ATR-IR and Raman) were employed to investigate the electronic structure and molecular interactions in the room-temperature ionic liquid 1-ethyl-3-methylimidazolium trifluoromethanesulfonate. Various possible conformers of a cation-anion pair based on their molecular interactions were simulated in the gas phase. All the different theoretical (MP2, B3LYP, and the dispersion-corrected wB97XD) methods assume the same ion-pair conformation for the lowest energy state. Basis set superimpose error (BSSE) correction was also introduced by using the counterpoise method. Strong C-H···O interactions between the most acidic hydrogen atom of the cation imidazole ring (C2H) and the oxygen atom of the anion were predicted where the anion is located at the top of (C2H). In this case, methyl and alkyl groups also interact with the anion in the form of a C-H···O hydrogen bond. Interestingly, the dispersion-corrected methodology neglects the C4/C5-H···O and C-H···F interaction in the ion-pair calculations. The theoretical results were compared with the experimental observations from Raman scattering and ATR-IR absorption spectroscopy, and the predictions of the molecular interactions in the vibrational spectra were discussed. The wavenumber shifts of the characteristic vibrations relative to the free cation and anion are explained by estimating the geometric parameters as well as the difference in the natural bond orbital (NBO) charge density. PMID:27429245

  2. Dynamic Percolation and Swollen Behavior of Nanodroplets in 1-Ethyl-3-methylimidazolium Trifluoromethanesulfonate/Triton X-100/Cyclohexane Microemulsions.

    PubMed

    Rahman, Adhip; Rahman, M Muhibur; Mollah, M Yousuf A; Susan, Md Abu Bin Hasan

    2016-07-21

    Microemulsions comprising an ionic liquid (IL), 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][OTf]), as the polar component, Triton X-100 as a surfactant, and cyclohexane as the nonpolar medium were prepared and characterized. Conductivity and dynamic viscosity data were critically analyzed to confirm dynamic percolation among the droplets that are in continuous motion, aggregation, and fission. The transition from oil-continuous phase to bicontinuous phase was observed at the conductance and viscosity percolation thresholds and sharp changes in the values of conductivity and dynamic viscosity could be identified. Dynamic light scattering measurements revealed swelling of the droplets, which varied within the hydrodynamic diameter range of 10-100 nm. Diffusivity of the droplets suggested less Brownian movement with increased amount of the IL. Moreover, changes in the droplet sizes and diffusivity with increase in IL content supported dynamic percolation within the systems. PMID:27355977

  3. Yeast tolerance to the ionic liquid 1-ethyl-3-methylimidazolium acetate.

    PubMed

    Sitepu, Irnayuli R; Shi, Shuang; Simmons, Blake A; Singer, Steven W; Boundy-Mills, Kyria; Simmons, Christopher W

    2014-12-01

    Lignocellulosic plant biomass is the target feedstock for production of second-generation biofuels. Ionic liquid (IL) pretreatment can enhance deconstruction of lignocellulosic biomass into sugars that can be fermented to ethanol. Although biomass is typically washed following IL pretreatment, small quantities of residual IL can inhibit fermentative microorganisms downstream, such as the widely used ethanologenic yeast, Saccharomyces cerevisiae. The aim of this study was to identify yeasts tolerant to the IL 1-ethyl-3-methylimidazolium acetate, one of the top performing ILs known for biomass pretreatment. One hundred and sixty eight strains spanning the Ascomycota and Basidiomycota phyla were selected for screening, with emphasis on yeasts within or closely related to the Saccharomyces genus and those tolerant to saline environments. Based on growth in media containing 1-ethyl-3-methylimidazolium acetate, tolerance to IL levels ranging 1-5% was observed for 80 strains. The effect of 1-ethyl-3-methylimidazolium acetate concentration on maximum cell density and growth rate was quantified to rank tolerance. The most tolerant yeasts included strains from the genera Clavispora, Debaryomyces, Galactomyces, Hyphopichia, Kazachstania, Meyerozyma, Naumovozyma, Wickerhamomyces, Yarrowia, and Zygoascus. These yeasts included species known to degrade plant cell wall polysaccharides and those capable of ethanol fermentation. These yeasts warrant further investigation for use in saccharification and fermentation of IL-pretreated lignocellulosic biomass to ethanol or other products. PMID:25348480

  4. Simulating the vibrational spectra of ionic liquid systems: 1-Ethyl-3-methylimidazolium acetate and its mixtures

    NASA Astrophysics Data System (ADS)

    Thomas, Martin; Brehm, Martin; Hollóczki, Oldamur; Kelemen, Zsolt; Nyulászi, László; Pasinszki, Tibor; Kirchner, Barbara

    2014-07-01

    The vibrational spectra of the ionic liquid 1-ethyl-3-methylimidazolium acetate and its mixtures with water and carbon dioxide are calculated using ab initio molecular dynamics simulations, and the results are compared to experimental data. The new implementation of a normal coordinate analysis in the trajectory analyzer TRAVIS is used to assign the experimentally observed bands to specific molecular vibrations. The applied computational approaches prove to be particularly suitable for the modeling of bulk phase effects on vibrational spectra, which are highly important for the discussion of the microscopic structure in systems with a strong dynamic network of intermolecular interactions, such as ionic liquids.

  5. Simulating the vibrational spectra of ionic liquid systems: 1-ethyl-3-methylimidazolium acetate and its mixtures.

    PubMed

    Thomas, Martin; Brehm, Martin; Hollóczki, Oldamur; Kelemen, Zsolt; Nyulászi, László; Pasinszki, Tibor; Kirchner, Barbara

    2014-07-14

    The vibrational spectra of the ionic liquid 1-ethyl-3-methylimidazolium acetate and its mixtures with water and carbon dioxide are calculated using ab initio molecular dynamics simulations, and the results are compared to experimental data. The new implementation of a normal coordinate analysis in the trajectory analyzer TRAVIS is used to assign the experimentally observed bands to specific molecular vibrations. The applied computational approaches prove to be particularly suitable for the modeling of bulk phase effects on vibrational spectra, which are highly important for the discussion of the microscopic structure in systems with a strong dynamic network of intermolecular interactions, such as ionic liquids. PMID:25028030

  6. Preparation of corn starch-g-polystyrene copolymer in ionic liquid: 1-ethyl-3-methylimidazolium acetate.

    PubMed

    Men, Yongjun; Du, Xiyan; Shen, Jianan; Wang, Leli; Liu, Zhengping

    2015-05-01

    The copolymer of starch grafted with polystyrene (starch-g-PS) was synthesized with high grafting percentage by utilizing the ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM]Ac) as solvent and potassium persulfate as initiator. The effect of various parameters upon the polymerization were studied including: initiator concentration, styrene:starch weight ratio, the reaction time and temperature. Grafting percentages were calculated using an FT-IR calibration method, with values up to 114%. The resulting copolymer was characterized using FT-IR, SEM, WAXD and TGA, which demonstrated that polystyrene side chains were evenly distributed on the starch backbone. Our results indicate that ionic liquid dissolution of starch, prior to polystyrene grafting, is a versatile methodology for the synthesis of amphiphilic, polysaccharide-based graft copolymers, having high grafting percent. PMID:25659709

  7. Reversible Carbene Formation in the Ionic Liquid 1-Ethyl-3-Methylimidazolium Acetate by Vaporization and Condensation.

    PubMed

    Kar, Bishnu Prasad; Sander, Wolfram

    2015-12-01

    The role of N-heterocyclic carbenes in the chemistry of ionic liquids based on imidazolium salts has long been discussed. Here, we present experimental evidence that 1-ethyl-3-methylimidazolium-2-ylidene (EMIm) can coexist with its protonated imidazolium cation (EMImH(+) ) at low temperatures. If the vapor of the ionic liquid [EMImH(+) ][AcO(-) ] is trapped in solid argon or nitrogen at 9 K, only acetic acid (AcOH) and the carbene, but no ionic species, are found by IR spectroscopy. This indicates that during the evaporation of [EMImH(+) ][AcO(-) ] proton transfer occurs to form the neutral species. If the vapor of [EMImH(+) ][AcO(-) ] is trapped at 9 K as film in the absence of a host matrix, a solid consisting of EMImH(+) , EMIm, AcO(-) , and AcOH is formed. During warming to room temperature the proton transfer in the solid to form back the IL [EMImH(+) ][AcO(-) ] can be monitored by IR spectroscopy. This clearly demonstrates that evaporation and condensation of the IL [EMImH(+) ][AcO(-) ] results in a double proton transfer, and the carbene EMIm is only metastable even at low temperatures. PMID:26376583

  8. Hormetic effect of ionic liquid 1-ethyl-3-methylimidazolium acetate on bacteria.

    PubMed

    Nancharaiah, Y V; Francis, A J

    2015-06-01

    The biological effect of ionic liquids (ILs) is one of the highly debated topics as they are being contemplated for various industrial applications. 1-ethyl-3-methylimidazolium acetate ([EMIM][Ac]) showed remarkable hormesis on anaerobic Clostridium sp. and aerobic Pseudomonas putida. Bacterial growth was stimulated at up to 2.5 g L(-1) and inhibited at >2.5 g L(-1) of [EMIM][Ac]. The growth of Clostridium sp. and P. putida were higher by 0.4 and 4-fold respectively, in the presence of 0.5 g L(-1) [EMIM][Ac]. Assessment of the effect of [EMIM][Ac] under different growth conditions showed that the hormesis of [EMIM][Ac] was mediated via regulation of medium pH. Hormetic effect of [EMIM][Ac] was evident only in medium with poor buffering capacity and in the presence of a fermentable substrate as the carbon source. The hormetic effect of [EMIM][Ac] on bacterial growth is most likely associated with the buffering capacity of acetate anion. These observations have implications in ILs toxicity studies and ecological risk assessment. PMID:25703901

  9. Physical insight into switchgrass dissolution in the ionic liquid 1-ethyl-3-methylimidazolium acetate

    SciTech Connect

    Wang, Hui; Gurau, Gabriela; Pingali, Sai Venkatesh; O'Neil, Hugh; Evans, Barbara R; Urban, Volker S; Heller, William T; Rogers, Robin D

    2014-01-01

    Small-angle neutron scattering was used to characterize solutions of switchgrass and the constituent biopolymers cellulose, hemicellulose, and lignin, as well as a physical mixture of them mimicking the composition of switchgrass, dissolved in the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate. The results demonstrate that the IL dissolves the cellulose fibrils of switchgrass, although a supramolecular biopolymer network remains that is not present in solutions of the individual biopolymers and that does not self-assemble in a solution containing the physical mixture of the individual biopolymers. The persistence of a network-like structure indicates that dissolving switchgrass in the IL does not disrupt all of the physical entanglements and covalent linkages between the biopolymers created during plant growth. Reconstitution of the IL-dissolved switchgrass yields carbohydrate-rich material containing cellulose with a low degree of crystallinity, as determined by powder X-ray diffraction, which impacts potential down-stream uses of the biopolymers produced by the process. The data suggests that the use of chemical additives which would break bonds that exist between the lignin and hemicellulose might improve the purity of the resulting product, but may not be able to disrupt the highly physically-entangled biopolymer network sufficiently to facilitate their separation.

  10. Coagulation of chitin and cellulose from 1-ethyl-3-methylimidazolium acetate ionic-liquid solutions using carbon dioxide.

    PubMed

    Barber, Patrick S; Griggs, Chris S; Gurau, Gabriela; Liu, Zhen; Li, Shan; Li, Zengxi; Lu, Xingmei; Zhang, Suojiang; Rogers, Robin D

    2013-11-18

    Chemisorption of carbon dioxide by 1-ethyl-3-methylimidazolium acetate ([C2 mim][OAc]) provides a route to coagulate chitin and cellulose from [C2 mim][OAc] solutions without the use of high-boiling antisolvents (e.g., water or ethanol). The use of CO2 chemisorption as an alternative coagulating process has the potential to provide an economical and energy-efficient method for recycling the ionic liquid. PMID:24115399

  11. Bacillus coagulans tolerance to 1-ethyl-3-methylimidazolium-based ionic liquids in aqueous and solid-state thermophilic culture.

    PubMed

    Simmons, Christopher W; Reddy, Amitha P; Vandergheynst, Jean S; Simmons, Blake A; Singer, Steven W

    2014-01-01

    The use of ionic liquids (ILs) to disrupt the recalcitrant structure of lignocellulose and make polysaccharides accessible to hydrolytic enzymes is an emerging technology for biomass pretreatment in lignocellulosic biofuel production. Despite efforts to reclaim and recycle IL from pretreated biomass, residual IL can be inhibitory to microorganisms used for downstream fermentation. As a result, pathways for IL tolerance are needed to improve the activity of fermentative organisms in the presence of IL. In this study, microbial communities from compost were cultured under high-solids and thermophilic conditions in the presence of 1-ethyl-3-methylimidazolium-based ILs to enrich for IL-tolerant microorganisms. A strain of Bacillus coagulans isolated from an IL-tolerant community was grown in liquid and solid-state culture in the presence of the ILs 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) or 1-ethyl-3-methylimidazolium chloride ([C2mim][Cl]) to gauge IL tolerance. Viability and respiration varied with the concentration of IL applied and the type of IL used. B. coagulans maintained growth and respiration in the presence of 4 wt% IL, a concentration similar to that present on IL-pretreated biomass. In the presence of both [C2mim][OAc] and [C2mim][Cl] in liquid culture, B. coagulans grew at a rate approximately half that observed in the absence of IL. However, in solid-state culture, the bacteria were significantly more tolerant to [C2mim][Cl] compared with [C2mim][OAc]. B. coagulans tolerance to IL under industrially relevant conditions makes it a promising bacterium for understanding mechanisms of IL tolerance and discovering IL tolerance pathways for use in other microorganisms, particularly those used in bioconversion of IL-pretreated plant biomass. PMID:24376258

  12. Effect of dimethyl sulfoxide on ionic liquid 1-ethyl-3-methylimidazolium acetate pretreatment of eucalyptus wood for enzymatic hydrolysis.

    PubMed

    Wu, Long; Lee, Seung-Hwan; Endo, Takashi

    2013-07-01

    Ground eucalyptus wood was pretreated with 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc)-dimethyl sulfoxide (DMSO) solutions with different mixing ratios under various conditions. The changes in the composition and structure of the biomass were investigated; and the enzymatic hydrolysis performance of the pretreated biomass was evaluated. [EMIM]OAc-DMSO pretreatment had a relatively mild effect on the composition of the biomass, but excessively high pretreatment temperatures led to massive loss of xylan after pretreatment. The enzymatic digestibility of the biomass was significantly improved with increased pretreatment temperature. X-ray diffraction analysis revealed that the disruption of cellulose crystal structure by [EMIM]OAc at a sufficiently high temperature was primarily responsible for the remarkable improvement in the digestibility. Appropriate addition of DMSO could help minimize the consumption of [EMIM]OAc without impairing the performance of the ionic liquid, and contribute to the improvement in pretreatment efficiency due to the viscosity reduction effect on the pretreatment liquor. PMID:23685645

  13. Rheological properties of concentrated solutions of gelatin in an ionic liquid 1-ethyl-3-methylimidazolium dimethyl phosphate.

    PubMed

    Horinaka, Jun-Ichi; Okamoto, Arisa; Takigawa, Toshikazu

    2016-10-01

    Rheological properties of gelatin solutions were examined in concentrated regions. Gelatin species from porcine skin and from bovine bone were dissolved in an ionic liquid 1-ethyl-3-methylimidazolium dimethyl phosphate. The dynamic viscoelasticity data for the solutions exhibited rubbery plateaus, indicating the existence of entanglement coupling between gelatin chains in the solutions. From the analogy with rubber elasticity, assuming that the molecular weight between entanglements (Me) is the average mesh size of the entanglement network, Me for gelatin in the solutions were determined from the heights of the rubbery plateaus. Then the value of Me in the molten state (Me,melt), a material constant reflecting the chemical structure of polymer species, for gelatin was estimated to be 8.7×10(3). Compared to synthetic polyamides whose Me,melt were known, Me,melt for gelatin was significantly larger, which could be explained by the densely repeating amide bonds composing gelatin. PMID:27311506

  14. Effect of the ionic liquid 1-ethyl-3-methylimidazolium acetate on the phase transition of starch: dissolution or gelatinization?

    PubMed

    Mateyawa, Sainimili; Xie, David Fengwei; Truss, Rowan W; Halley, Peter J; Nicholson, Timothy M; Shamshina, Julia L; Rogers, Robin D; Boehm, Michael W; McNally, Tony

    2013-04-15

    This work revealed that the interactions between starch, the ionic liquid 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]), and water might contribute to the phase transition (gelatinization, dissolution, or both) of native starch at reduced temperature. Using mixtures of water and [Emim][OAc] at certain ratios (7.2/1 and 10.8/1 mol/mol), both the gelatinization and dissolution of the starch occur competitively, but also in a synergistic manner. At lower [Emim][OAc] concentration (water/[Emim][OAc] molar ratio≥25.0/1), mainly gelatinization occurs which is slightly impeded by the strong interaction between water and [Emim][OAc]; while at higher [Emim][OAc] concentration (water/[Emim][OAc] molar ratio≤2.8/1), the dissolution of starch is the major form of phase transition, possibly restricted by the difficulty of [Emim][OAc] to interact with starch. PMID:23544570

  15. Probing solute-solvent interaction in 1-ethyl-3-methylimidazolium-based room temperature ionic liquids: A time-resolved fluorescence anisotropy study.

    PubMed

    Das, Sudhir Kumar; Sarkar, Moloy

    2014-03-01

    Rotational diffusion of two organic solutes, coumarin153 (C153) and 4-aminophthalimide (AP) has been investigated in four ionic liquids (ILs), viz. 1-ethyl-3-methylimidazolium trifluoroacetate (EMIMTFA), 1-ethyl-3-methylimidazolium ethylsulfate (EMIMESU), 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMTFB) and 1-ethyl-3-methylimidazolium tetracyanoborate (EMIMTCB), as a function of temperature. Between the two probes, AP can act as hydrogen-bond-donor to the solvents having hydrogen bond acceptor ability. The results indicate that the rotational dynamics of C153 is mainly governed by the viscosity of the medium. On the other hand, the rotational motion of AP is found to be significantly hindered in the ILs depending on the nature of anions of the ILs. Rotational coupling constant values for AP in the ILs follow the order TFA > ESU > TCB > TFB. The slower rotational motion of AP in these ILs has been attributed to the specific hydrogen bonding interaction between AP and anions of ILs. PMID:24158315

  16. Simulations reveal conformational changes of methylhydroxyl groups during dissolution of cellulose Iβ in ionic liquid 1-ethyl-3-methylimidazolium acetate.

    PubMed

    Liu, Hanbin; Cheng, Gang; Kent, Michael; Stavila, Vitalie; Simmons, Blake A; Sale, Kenneth L; Singh, Seema

    2012-07-19

    In this work, we use molecular dynamics (MD) simulations to study the dissolution of microcrystalline cellulose in the ionic liquid 1-ethyl-3-methylimidazolium acetate (abbreviated as [C2mim][OAc]) at 20 wt % loading. The interactions of [C2mim][OAc] with the Iβ cellulose structure at 120 °C were studied. The results show that both the cation and the anion of [C2mim][OAc] penetrate into the cellulose Iβ crystal structure but that the anion in particular forms strong hydrogen bonds with cellulose. Our results also show that the methylhydroxyl groups of cellulose solvated in [C2mim][OAc] are predominantly in the gauche-trans (gt) conformation, in contrast to the dominant trans-gauche (tg) conformation of cellulose Iβ in air or the gauche-gauche (gg) conformation for cellulose chains in water or after pretreatment with ammonia. Because the gt conformation is found mainly in cellulose II, these simulations suggest that regenerated cellulose under similar pretreatment conditions is composed mainly of cellulose II, and this result was confirmed by X-ray diffraction of samples processed under similar pretreatment conditions. These simulations provide new insight into the efficacy of [C2mim][OAc] pretreatment, suggesting that [C2mim][OAc] interacts with and biases the methylhydroxyl groups of cellulose toward orientations that are consistent with the experimentally observed more easily hydrolyzed cellulose II. PMID:22574852

  17. Physical Properties and CO2 Reaction Pathway of 1-Ethyl-3-Methylimidazolium Ionic Liquids with Aprotic Heterocyclic Anions

    SciTech Connect

    Seo, S; DeSilva, MA; Brennecke, JF

    2014-12-25

    Ionic liquids (ILs) with aprotic heterocyclic anions (AHA) are attractive candidates for CO2 capture technologies. In this study, a series of AHA ILs with 1-ethyl-3-methylimidazolium ([emim](+)) cations were synthesized, and their physical properties (density, viscosity, and ionic conductivity) were measured. In addition, CO2 solubility in each IL was determined at room temperature using a volumetric method at pressures between 0 and 1 bar. The AHAs are basic anions that are capable of reacting stoichiometrically with CO2 to form carbamate species. An interesting CO2 uptake isotherm behavior was observed, and this may be attributed to a parallel, equilibrium proton exchange process between the imidazolium cation and the basic AHA in the presence of CO2, followed by the formation of "transient" carbene species that react rapidly with CO2. The presence of the imidazolium-carboxylate species and carbamate anion species was verified using H-1 and C-13 NMR spectroscopy. While the reaction between CO2 and the proposed transient carbene resulted in cation-CO2 binding that is stronger than the anion-CO2 reaction, the reactions of the imidazolium AHA ILs were fully reversible upon regeneration at 80 degrees C with nitrogen purging. The presence of water decreased the CO2 uptake due to the inhibiting effect of the neutral species (protonated form of AHA) that is formed.

  18. Hormetic effect of ionic liquid 1-ethyl-3-methylimidazolium acetate on bacteria

    SciTech Connect

    Nancharaiah, Y. V.; Francis, A. J.

    2015-02-19

    The biological effect of ionic liquids (ILs) is one of the highly debated topics as they are being contemplated for various industrial applications. 1-ethyl-2-methylimidazolium acetate ([EMIM][Ac]) showed remarkable hormesis on anaerobic Clostridium sp. and aerobic Psueudomonas putida. Bacterial growth was stimulated at up to 2.5 g L-1 and inhibited at > 2.5 g L-1 of ([EMIM][Ac]). The growth of Clostridium sp. and P. putida were higher by 0.4 and 4-fold respectively, in the presense of 0.5 g L-1 of ([EMIM][Ac]). Assessment of the effect of [EMIM][Ac] under different growth conditions showed that the hormesis of [EMIM][Ac] was mediated via regulation of medium pH. Hormetic effect of [EMIM][Ac] was evident only in medium with poor buffering capacity and in the presence of a fermentable substrate as the carbon source. The hormetic effect of [EMIM][Ac] on bacterial growth is most likely associated with the buffering capacity of acetate anion. These observations have implications in ILs toxicity studies and ecological risk assessment.

  19. Hormetic effect of ionic liquid 1-ethyl-3-methylimidazolium acetate on bacteria

    DOE PAGESBeta

    Nancharaiah, Y. V.; Francis, A. J.

    2015-02-19

    The biological effect of ionic liquids (ILs) is one of the highly debated topics as they are being contemplated for various industrial applications. 1-ethyl-2-methylimidazolium acetate ([EMIM][Ac]) showed remarkable hormesis on anaerobic Clostridium sp. and aerobic Psueudomonas putida. Bacterial growth was stimulated at up to 2.5 g L-1 and inhibited at > 2.5 g L-1 of ([EMIM][Ac]). The growth of Clostridium sp. and P. putida were higher by 0.4 and 4-fold respectively, in the presense of 0.5 g L-1 of ([EMIM][Ac]). Assessment of the effect of [EMIM][Ac] under different growth conditions showed that the hormesis of [EMIM][Ac] was mediated via regulationmore » of medium pH. Hormetic effect of [EMIM][Ac] was evident only in medium with poor buffering capacity and in the presence of a fermentable substrate as the carbon source. The hormetic effect of [EMIM][Ac] on bacterial growth is most likely associated with the buffering capacity of acetate anion. These observations have implications in ILs toxicity studies and ecological risk assessment.« less

  20. The Effect of Hydrophilic Ionic Liquids 1-Ethyl-3-Methylimidazolium Lactate and Choline Lactate on Lipid Vesicle Fusion

    PubMed Central

    Hayakawa, Eri H.; Mochizuki, Eiko; Tsuda, Tetsuya; Akiyoshi, Kazunari; Matsuoka, Hiroyuki; Kuwabata, Susumu

    2013-01-01

    Ionic liquids (ILs) are room-temperature molten salts that have applications in both physical sciences and more recently in the purification of proteins and lipids, gene transfection and sample preparation for electron microscopy (EM) studies. Transfection of genes into cells requires membrane fusion between the cell membrane and the transfection reagent, thus, ILs may be induce a membrane fusion event. To clarify the behavior of ILs with cell membranes the effect of ILs on model membranes, i.e., liposomes, were investigated. We used two standard ILs, 1-ethyl-3-methylimidazolium lactate ([EMI][Lac]) and choline lactate ([Ch][Lac]), and focused on whether these ILs can induce lipid vesicle fusion. Fluorescence resonance energy transfer and dynamic light scattering were employed to determine whether the ILs induced vesicle fusion. Vesicle solutions at low IL concentrations showed negligible fusion when compared with the controls in the absence of ILs. At concentrations of 30% (v/v), both types of ILs induced vesicle fusion up to 1.3 and 1.6 times the fluorescence intensity of the control in the presence of [Ch][Lac] and [EMI][Lac], respectively. This is the first demonstration that [EMI][Lac] and [Ch][Lac] induce vesicle fusion at high IL concentrations and this observation should have a significant influence on basic biophysical studies. Conversely, the ability to avoid vesicle fusion at low IL concentrations is clearly advantageous for EM studies of lipid samples and cells. This new information describing IL-lipid membrane interactions should impact EM observations examining cell morphology. PMID:24392011

  1. Fluorohydrogenate Cluster Ions in the Gas Phase: Electrospray Ionization Mass Spectrometry of the [1-Ethyl-3-methylimidazolium+][F(HF)2.3–] Ionic Liquid

    SciTech Connect

    Gary S. Groenewold; James E. Delmore; Michael T. Benson; Tetsuya Tsuda; Rika Hagiwara

    2013-12-01

    Electrospray ionization of the fluorohydrogenate ionic liquid [1-ethyl-3-methylimidazolium][F(HF)2.3] ionic liquid was conducted to understand the nature of the anionic species as they exist in the gas phase. Abundant fluorohydrogenate clusters were produced; however, the dominant anion in the clusters was [FHF-], and not the fluoride-bound HF dimers or trimers that are seen in solution. Density functional theory (DFT) calculations suggest that HF molecules are bound to the clusters by about 30 kcal/mol. The DFT-calculated structures of the [FHF-]-bearing clusters show that the favored interactions of the anions are with the methynic and acetylenic hydrogen atoms on the imidazolium cation, forming planar structures similar to those observed in the solid state. A second series of abundant negative ions was also formed that contained [SiF5-] together with the imidazolium cation and the fluorohydrogenate anions that originate from reaction of the spray solution with silicate surfaces.

  2. Synergistic effect of delignification and treatment with the ionic liquid 1-ethyl-3-methylimidazolium acetate on enzymatic digestibility of poplar wood.

    PubMed

    Wu, Long; Kumagai, Akio; Lee, Seung-Hwan; Endo, Takashi

    2014-06-01

    This study examined the effects of removing key recalcitrance factors by ionic liquid (IL) treatment on the cellulase digestibility of poplar wood. Ground biomass was subjected to chlorite delignification and IL (1-ethyl-3-methylimidazolium acetate) treatment alone or in combination. The compositional and structural features of differentially treated biomass samples and their hydrolysis performance at various cellulase loadings were investigated. IL treatment caused minor compositional changes but drastically decreased cellulose crystallinity; in particular, when administered after delignification, an X-ray diffractogram similar to that of cellulose II polymorph was observed, suggesting that in the absence of lignin, the cellulose was dissolved in the IL and regenerated in water with a polymorphic transformation. The structural changes induced by the combined delignification-IL treatment facilitated the enzymatic hydrolysis of cellulose; the biomass could be fully degraded within 72 h by 4 FPU of cellulase per gram glucan, with cellobiose degradation being the rate-limiting step. PMID:24755318

  3. Physical properties and solubility parameters of 1-ethyl-3-methylimidazolium based ionic liquids/DMSO mixtures at 298.15 K

    NASA Astrophysics Data System (ADS)

    Saba, H.; Yumei, Z.; Huaping, W.

    2015-12-01

    Densities, refractive indices, conductivities and viscosities of binary mixtures of 1-ethyl-3-methylimidazolium-based ionic liquids (ILs) with dimethyl sulfoxide at 298.15 K are reported. Excess molar volumes have been calculated from experimental data and were fitted with Redlich-Kister equation. The density and refractive index were found to increase with increasing concentration in all cases except [EMIM]COOH. The free mobility of ions has found to enhance conductivity and decrease viscosity to varying extent in all mixtures being studied. It has been observed that solubility parameters, dielectric constants and nature of anions of ILs being used play a vital role in determining the subsequent characteristics. As DMSO has high dielectric constant therefore, it was able to form interactions with most of ILs except with [EMIM]COOH due to anomalous nature of anion.

  4. Direct Electrodeposition of UO2 from Uranyl Bis(trifluoromethanesulfonyl)imide Dissolved in 1-Ethyl-3-methylimidazolium Bis(trifluoromethanesulfonyl)imide Room Temperature Ionic Liquid System

    DOE PAGESBeta

    Freiderich, John W.; Wanigasekara, Eranda P.; Sun, Xiao-Guang; Meisner, Roberta Ann; Meyer, III, Harry M.; Luo, Huimin; Delmau, Laetitia Helene; Dai, Sheng; Moyer, Bruce A

    2013-11-11

    Our study demonstrates a direct electrodeposition of UO2 at a Pt cathode from a solution of uranyl bis(trifluoromethanesulfonyl)imide [UO2(NTf2)2)] in a bulk room-temperature ionic liquid (RTIL), 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMIM+NTf2–). Cyclic voltammetry (CV) studies revealed two reduction waves corresponding to the conversion of uranium(VI) to uranium(IV), and a mechanism for the overall electroreduction is proposed. A controlled-potential experiment was performed, holding the reduction potential at–1.0 V for 24 h to obtain a brown-black deposit of UO2 on the Pt cathode. The Faradaic efficiency of the reduction process was determined to be >80%. The UO2deposit was characterized by powder X-ray diffraction (XRD)more » and X-ray photoelectron spectroscopy (XPS).« less

  5. Layering and shear properties of an ionic liquid, 1-ethyl-3-methylimidazolium ethylsulfate, confined to nano-films between mica surfaces.

    PubMed

    Perkin, Susan; Albrecht, Tim; Klein, Jacob

    2010-02-14

    We report high-resolution measurements of the forces between two atomically smooth solid surfaces across a film of 1-ethyl-3-methylimidazolium ethylsulfate ionic liquid, for film thickness down to a single ion diameter. For films thinner than approximately 2 nm oscillatory structural forces are observed as the surface separation decreases and pairs of ion layers are squeezed out of the film. Strikingly, measurements of the shear stress of the ionic liquid film reveal low friction coefficients which are 1-2 orders of magnitude smaller than for analogous films of non-polar molecular liquids, including standard hydrocarbon lubricants, up to ca. 1 MPa pressure. We attribute this to the geometric and charge characteristics of the ionic liquid: the irregular shapes of the ions lead to a low shear stress, while the strong coulombic interactions between the ions and the charged confining surfaces lead to a robust film which is maintained between the shearing surfaces when pressure is applied across the film. PMID:20119601

  6. Simultaneous measurement of speed of sound, thermal diffusivity, and bulk viscosity of 1-ethyl-3-methylimidazolium-based ionic liquids using laser-induced gratings.

    PubMed

    Kozlov, Dimitrii N; Kiefer, Johannes; Seeger, Thomas; Fröba, Andreas P; Leipertz, Alfred

    2014-12-11

    The technique of laser-induced gratings (LIGs) has been applied to the simultaneous determination of speed of sound and thermal diffusivity of four 1-ethyl-3-methylimidazolium ([EMIm])-based room temperature ionic liquids (RTILs)-[EMIm][N(CN)2], [EMIm][MeSO3], [EMIm][C(CN)3], and [EMIm][NTf2]-at ambient pressure (1 bar (0.1 MPa)) and temperature (28 °C (301 K)). Transient laser-induced gratings were created as a result of thermalization of a quasi-resonant excitation of highly lying combinational vibrational states of the RTIL molecules and electrostrictive compression of the liquid by radiation of a pulse-repetitive Q-switched Nd:YAG pump laser (1064 nm). The LIGs temporal evolution was recorded using Bragg diffraction of the radiation from a continuous-wave probe laser (532 nm). By fitting the temporal profiles of the LIG signals, the speed of sound and thermal diffusivity were determined, and the isentropic compressibility and thermal conductivity were calculated. Independently, the special experimental arrangement allowed the measurement of the damping of the laser-excited acoustic waves and the derivation of the RTIL bulk viscosity for the first time. PMID:25415848

  7. Direct Electrodeposition of UO2 from Uranyl Bis(trifluoromethanesulfonyl)imide Dissolved in 1-Ethyl-3-methylimidazolium Bis(trifluoromethanesulfonyl)imide Room Temperature Ionic Liquid System

    SciTech Connect

    Freiderich, John W.; Wanigasekara, Eranda P.; Sun, Xiao-Guang; Meisner, Roberta Ann; Meyer, III, Harry M.; Luo, Huimin; Delmau, Laetitia Helene; Dai, Sheng; Moyer, Bruce A

    2013-11-11

    Our study demonstrates a direct electrodeposition of UO2 at a Pt cathode from a solution of uranyl bis(trifluoromethanesulfonyl)imide [UO2(NTf2)2)] in a bulk room-temperature ionic liquid (RTIL), 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMIM+NTf2). Cyclic voltammetry (CV) studies revealed two reduction waves corresponding to the conversion of uranium(VI) to uranium(IV), and a mechanism for the overall electroreduction is proposed. A controlled-potential experiment was performed, holding the reduction potential at–1.0 V for 24 h to obtain a brown-black deposit of UO2 on the Pt cathode. The Faradaic efficiency of the reduction process was determined to be >80%. The UO2deposit was characterized by powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS).

  8. Mixtures of the 1-ethyl-3-methylimidazolium acetate ionic liquid with different inorganic salts: insights into their interactions.

    PubMed

    Oliveira, Filipe S; Cabrita, Eurico J; Todorovic, Smilja; Bernardes, Carlos E S; Lopes, José N Canongia; Hodgson, Jennifer L; MacFarlane, Douglas R; Rebelo, Luís P N; Marrucho, Isabel M

    2016-01-28

    In this work, we explore the interactions between the ionic liquid 1-ethyl-3-methylimidazolim acetate and different inorganic salts belonging to two different cation families, those based on ammonium and others based on sodium. NMR and Raman spectroscopy are used to screen for changes in the molecular environment of the ions in the ionic liquid + inorganic salt mixtures as compared to pure ionic liquid. The ion self-diffusion coefficients are determined from NMR data, allowing the discussion of the ionicity values of the ionic liquid + inorganic salt mixtures calculated using different methods. Our data reveal that preferential interactions are established between the ionic liquid and ammonium-based salts, as opposed to sodium-based salts. Computational calculations show the formation of aggregates between the ionic liquid and the inorganic salt, which is consistent with the spectroscopic data, and indicate that the acetate anion of the ionic liquid establishes preferential interactions with the ammonium cation of the inorganic salts, leaving the imidazolium cation less engaged in the media. PMID:26725329

  9. Rotational dynamics of coumarin-153 and 4-aminophthalimide in 1-ethyl-3-methylimidazolium alkylsulfate ionic liquids: effect of alkyl chain length on the rotational dynamics.

    PubMed

    Das, Sudhir Kumar; Sarkar, Moloy

    2012-01-12

    Rotational dynamics of two neutral organic solutes, coumarin-153 (C-153) and 4-aminophthalimide (AP), with only the latter having hydrogen-bond-donating ability, has been investigated in a series of 1-ethyl-3-methylimidazolium alkyl sulfate ionic liquids as a function of temperature. The ionic liquids differ only in the length of the linear alkyl side chain (alkyl = ethyl, butyl, hexyl, and octyl) on the anionic moiety. The present study has been undertaken to examine the role of alkyl side chains on the rotational dynamics of the two solutes in these ionic liquids. Analysis of the results using Stokes-Einstein-Debye hydrodynamic theory indicates that the rotational dynamics of C-153 lies between the stick and slip boundary condition in the ethyl analogue and finally reaches subslip condition as in case of the octyl substituent. The observed rotational behavior of C-153 has been explained on the basis of an increase in the size of the solvent, which offers lower friction for solute rotation. On the other hand, AP shows superstick behavior in the ethyl system and exceeds the stick limit in the octyl derivative. Superstick behavior of AP has been attributed to the specific hydrogen-bonding interaction between AP and the sulfate moiety. Proton NMR investigation confirms the hydrogen-bonding interaction between the N-H hydrogen of AP and the ionic liquid. The decrease in rotational coupling constant values for AP with increasing length of alkyl side chains has been attributed to the decrease in the solute-solvent-specific interaction with an increase in the alkyl side chain length on the sulfate moiety. PMID:22112024

  10. Characteristics of starch-based films plasticised by glycerol and by the ionic liquid 1-ethyl-3-methylimidazolium acetate: a comparative study.

    PubMed

    Xie, Fengwei; Flanagan, Bernadine M; Li, Ming; Sangwan, Parveen; Truss, Rowan W; Halley, Peter J; Strounina, Ekaterina V; Whittaker, Andrew K; Gidley, Michael J; Dean, Katherine M; Shamshina, Julia L; Rogers, Robin D; McNally, Tony

    2014-10-13

    This paper reports the plasticisation effect of the ionic liquid, 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]), as compared with the traditionally used plasticiser, glycerol, on the characteristics of starch-based films. For minimising the additional effect of processing, a simple compression moulding process (which involves minimal shear) was used for preparation of starch-based films. The results show that [Emim][OAc] was favourable for plasticisation, i.e., disruption of starch granules (by scanning electron microscopy), and could result in a more amorphous structure in the starch-based materials (by X-ray diffraction and dynamic mechanical analysis). (13)C CP/MAS and SPE/MAS NMR spectroscopy revealed that not only was the crystallinity reduced by [Emim][OAc], but also the amorphous starch present was plasticised to a more mobile form as indicated by the appearance of amorphous starch in the SPE/MAS spectrum. Mechanical results illustrate that, when either glycerol or [Emim][OAc] was used, a higher plasticiser content could contribute to higher flexibility. In spite of the accelerated thermal degradation of starch by [Emim][OAc] as shown by thermogravimetric analysis, the biodegradation study revealed the antimicrobial effect of [Emim][OAc] on the starch-based materials. Considering the high-amylose starch used here which is typically difficult to gelatinise in a traditional plasticiser (water and/or glycerol), [Emim][OAc] is demonstrated to be a promising plasticiser for starch to develop "green" flexible antimicrobial materials for novel applications. PMID:25037423

  11. [CuCln](2-n) Ion-Pair Species in 1-Ethyl-3-Methylimidazolium Chloride Ionic Liquid-Water Mixtures: Ultraviolet-Visible, X-ray Absorbtion Fine Structure, and Density Functional Theory Characterization

    SciTech Connect

    Li, Guosheng; Camaioni, Donald M.; Amonette, James E.; Zhang, Z. Conrad; Johnson, Timothy J.; Fulton, John L.

    2010-10-07

    We report details of the coordination environment about Cu(II) in a pure ionic liquid, 1- ethyl-3-methylimidazolium chloride ([EMIM]Cl) and in mixtures containing varying amounts of water from 0-100% of the [EMIM]Cl. There are many stages in the ion pairing of the divalent cation, Cu(II) including the contact ion pairing of Cu2+ with multiple Cl- to form various CuCln (2-n) polyanions. Thereis also the subsequent solvation and ion pairing of the polychlorometallate anion with the EMIM+ cation. Using a combination of x-ray absorption fine structure (XAFS), UV-Vis spectroscopy and electronic structure calculations (TDDFT) we are able to follow the detailed structural changes about Cu(II). Ion pair formation is strongly promoted in [EMIM]Cl by the low dielectric constant and by the extensive breakdown of the water hydrogen bond network in [EMIM]Cl/water mixtures. In the [EMIM]Cl solvent the CuCl4 2- species dominates and it’s geometry is quite similar to gas-phase structure. These results are important in understanding catalysis and separation processes involving transition metals in ionic liquid systems.

  12. Enrichment, isolation and characterization of fungi tolerant to 1-ethyl-3-methylimidazolium acetate

    SciTech Connect

    Singer, S.W.; Reddy, A. P.; Gladden, J. M.; Guo, H.; Hazen, T.C.; Simmons, B. A.; VanderGheynst, J. S.

    2010-12-15

    This work aims to characterize microbial tolerance to 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]), ionic liquid that has emerged as a novel biomass pretreatment for lignocellulosic biomass. Enrichment experiments performed using inocula treated with [C2mim][OAc] under solid and liquid cultivation yielded fungal populationsdominated by Aspergilli. Ionic liquid-tolerant Aspergillus isolates from these enrichments were capable of growing in a radial plate growth assay in the presence of 10% [C2mim][OAc]. When a [C2mim][OAc]-tolerant Aspergillus fumigatus strain was grown in the presence of switchgrass, endoglucanases and xylanases were secreted that retained residual enzymatic activity in the presence of 20% [C2mim][OAc]. The results of the study suggest tolerance to ionic liquids is a general property of Aspergilli. Tolerance to an industrially important ionic liquid was discovered in a fungal genera that is widely used in biotechnology, including biomass deconstruction.

  13. Glucosamine condensation catalyzed by 1-ethyl-3-methylimidazolium acetate: mechanistic insight from NMR spectroscopy.

    PubMed

    Jia, Lingyu; Pedersen, Christian Marcus; Qiao, Yan; Deng, Tiansheng; Zuo, Pingping; Ge, Wenzhi; Qin, Zhangfeng; Hou, Xianglin; Wang, Yingxiong

    2015-09-21

    The basic ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2C1Im][OAc]) could efficiently catalyze the conversion of 2-amino-2-deoxy-d-glucose (GlcNH2) into deoxyfructosazine (DOF) and fructosazine (FZ). Mechanistic investigation by NMR studies disclosed that [C2C1Im][OAc], exhibiting strong hydrogen bonding basicity, could coordinate with the hydroxyl and amino groups of GlcNH2via the promotion of hydrogen bonding in bifunctional activation of substrates and further catalyzing product formation, based on which a plausible reaction pathway involved in this homogeneous base-catalyzed reaction was proposed. Hydrogen bonding as an activation force, therefore, is responsible for the remarkable selectivity and rate enhancement observed. PMID:26278065

  14. Removal of 1-ethyl-3-methylimidazolium cations with bacterial biosorbents from aqueous media.

    PubMed

    Won, Sung Wook; Choi, Sun Beom; Mao, Juan; Yun, Yeoung-Sang

    2013-01-15

    This study aims to determine whether biosorption can be used for the removal of ionic liquids (ILs), especially their cationic parts, from aqueous media. As a model IL, 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) was used. Five types of bacterial biosorbents were prepared from fermentation wastes through chemical modification of the bacterial surface. Screening study was performed to compare the cationic [EMIM] biosorption capacity among the bacterial biosorbents, indicating that the succinated Escherichia coli biomass (SB-E) was the best biosorbent for removing [EMIM] cations. The [EMIM] biosorption performance of SB-E was evaluated in detail through various experiments. The optimal pH range for [EMIM] biosorption was from 7 to 10, and biosorption equilibrium was reached within 10 min. The maximum uptake of SB-E was also estimated to be 72.6 mg/g. Moreover, [EMIM] cations were easily desorbed from [EMIM]-sorbed SB-E by adding acetic acid. PMID:23246948

  15. Nuclear magnetic resonance studies on the rotational and translational motions of ionic liquids composed of 1-ethyl-3-methylimidazolium cation and bis(trifluoromethanesulfonyl)amide and bis(fluorosulfonyl)amide anions and their binary systems including lithium salts

    NASA Astrophysics Data System (ADS)

    Hayamizu, Kikuko; Tsuzuki, Seiji; Seki, Shiro; Umebayashi, Yasuhiro

    2011-08-01

    Room temperature ionic liquids (ILs) are stable liquids composed of anions and cations. 1-ethyl-3-methyl-imidazolium (EMIm, EMI) is a popular and important cation that produces thermally stable ILs with various anions. In this study two amide-type anions, bis(trifluoro-methanesulfonyl)amide [N(SO2CF3)2, TFSA, TFSI, NTf2, or Tf2N] and bis(fluorosulfonyl)amide [(N(SO2F)2, FSA, or FSI] were investigated by multinuclear NMR spectroscopy. In addition to EMIm-TFSA and EMIm-FSA, lithium-salt-doped binary systems were prepared (EMIm-TFSA-Li and EMIm-FSA-Li). The spin-lattice relaxation times (T1) were measured by 1H, 19F, and 7Li NMR spectroscopy and the correlation times of 1H NMR, τc(EMIm) (8 × 10-10 to 3 × 10-11 s) for the librational molecular motion of EMIm and those of 7Li NMR, τc(Li) (5 × 10-9 to 2 × 10-10 s) for a lithium jump were evaluated in the temperature range between 253 and 353 K. We found that the bulk viscosity (η) versus τc(EMIm) and cation diffusion coefficient DEMIm versus the rate 1/τc(EMIm) have good relationships. Similarly, linear relations were obtained for the η versus τc(Li) and the lithium diffusion coefficient DLi versus the rate 1/τc(Li). The mean one-jump distances of Li were calculated from τc(Li) and DLi. The experimental values for the diffusion coefficients, ionic conductivity, viscosity, and density in our previous paper were analyzed by the Stokes-Einstein, Nernst-Einstein, and Stokes-Einstein-Debye equations for the neat and binary ILs to clarify the physicochemical properties and mobility of individual ions. The deviations from the classical equations are discussed.

  16. Monitoring of cellulose depolymerization in 1-ethyl-3-methylimidazolium acetate by shear and elongational rheology.

    PubMed

    Michud, Anne; Hummel, Michael; Haward, Simon; Sixta, Herbert

    2015-03-01

    The thermal stability of cellulose in the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate, [emim]OAc was investigated. For this purpose, Eucalyptus urugrandis prehydrolysis kraft pulp was first dissolved in [emim]OAc by means of a vertical kneader and then stored at three different temperatures to study the time-depended behavior of the cellulose-[emim]OAc system. Cellulose depolymerization was assessed by characterizing the precipitated cellulose and the rheological behavior of the cellulose-[emim]OAc solutions. The results show decreases in the weight average molecular mass and in the shear viscosity at temperatures exceeding 60 °C, which can be related to progressing degradation of cellulose in the IL upon storage at elevated temperature. The changes in behavior of the solutions under extensional stresses also attest the gradual depolymerization of cellulose. The degradation has been analyzed using appropriate kinetic models. Propyl gallate appeared to be an efficient stabilizer of the cellulose-[emim]OAc system during the dissolution step even though the mechanism has not been fully understood yet. PMID:25498646

  17. Molecular Interactions in 1-Ethyl-3-methylimidazolium Acetate Ion Pair: A Density Functional Study

    NASA Astrophysics Data System (ADS)

    Dhumal, Nilesh R.; Kim, Hyung J.; Kiefer, Johannes

    2009-08-01

    The density functional method is used to obtain the molecular structure, electron density topography, and vibrational frequencies of the ion pair 1-ethyl-3-methylimidazolium acetate. Different conformers are simulated on the basis of molecular interactions between the 1-ethyl-3-methylimidazolium cation and acetate anion. The lowest energy conformers exhibit strong C-H···O interionic interactions compared with other conformers. Characteristic vibrational frequencies of the ion pair and their shifts with respect to free ions are analyzed via the natural bond orbitals and difference electron density maps coupled with molecular electron density topology. Theoretically scaled vibrational frequencies are also compared with the spontaneous Raman scattering and attenuated total reflection infrared absorption measurements.

  18. Solvent effects of 1-ethyl-3-methylimidazolium acetate: solvation and dynamic behavior of polar and apolar solutes.

    PubMed

    Lesch, Volker; Heuer, Andreas; Holm, Christian; Smiatek, Jens

    2015-04-01

    We study the solvation properties of the ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM](+)[ACE](-)) and the resulting dynamic behavior for differently charged model solutes at room temperature via atomistic molecular dynamics (MD) simulations of 300 ns length and 200 ns equilibration time. The solutes are simple model spheres which are either positively or negatively charged with a valency of one, or uncharged. The numerical findings indicate a distinct solvation behavior with the occurrence of well-pronounced solvation shells whose composition significantly depends on the charge of the solute. All the results of our simulations evidence the existence of a long-range perturbation effect in presence of the solutes. Our findings validate the dominance of electrostatic interactions with regard to unfavorable entropic ordering effects which elucidates the enthalpic character of the solvation process in ionic liquids for charged solutes. PMID:25680082

  19. Characteristics of starch-based films with different amylose contents plasticised by 1-ethyl-3-methylimidazolium acetate.

    PubMed

    Xie, Fengwei; Flanagan, Bernadine M; Li, Ming; Truss, Rowan W; Halley, Peter J; Gidley, Michael J; McNally, Tony; Shamshina, Julia L; Rogers, Robin D

    2015-05-20

    Starch-based films plasticised by an ionic liquid, 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]), were prepared by a simple compression moulding process, facilitated by the strong plasticisation effect of [Emim][OAc]. The effects of amylose content of starch (regular vs. high-amylose maize) and relative humidity (RH) during ageing of the samples on a range of structural and material characteristics were investigated. Surprisingly, plasticisation by [Emim][OAc] made the effect of amylose content insignificant, contrary to most previous studies when other plasticisers were used. In other words, [Emim][OAc] changed the underlying mechanism responsible for mechanical properties from the entanglement of starch macromolecules (mainly amylose), which has been reported as a main responsible factor previously. The crystallinity of the plasticised starch samples was low and thus was unlikely to have a major contribution to the material characteristics, although the amylose content impacted on the crystalline structure and the mobility of amorphous parts in the samples to some extent. Therefore, RH conditioning and thus the sample water content was the major factor influencing the mechanical properties, glass transition temperature, and electrical conductivity of the starch films. This suggests the potential application of ionic liquid-plasticised starch materials in areas where the control of properties by environmental RH is desired. PMID:25817655

  20. Phase transition of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide thin films on highly oriented pyrolytic graphite.

    PubMed

    Souda, Ryutaro

    2009-10-01

    Thin glassy films of a room-temperature ionic liquid, 1-ethyl-3-methylimidazolium bis[trifluoromethylsulfonyl]imide ([emim][Tf(2)N]), were deposited by thermal evaporation onto a substrate of highly oriented pyrolytic graphite. Their crystallization and fusion kinetics are discussed on the basis of results of time-of-flight secondary-ion mass spectrometry (TOF-SIMS) by measuring sputtered secondary-ion intensities as a function of temperature. Multilayer films crystallize at 205 K and then fuse at 255 K, as determined from temperature-programmed TOF-SIMS measurements, whereas crystallization occurs at around the glass-transition temperature (175-180 K) within 10 min, as shown by isothermal TOF-SIMS measurements. The ionic pairs in the [emim][Tf(2)N] monolayer tend to align over a wide temperature range of 180-220 K and retain crystal-like alignment up to 285 K. The weak van der Waals interaction at the interface is thought to be prerequisite for the aligned monolayer formation, because the ionic pairs on a Ni(111) substrate tend to be disordered. Thus, it is demonstrated that the alignment and wettability of the first monolayer, as well as the crystallization and fusion kinetics of thin films, are influenced by the substrate. PMID:19725572

  1. Different characteristic effects of ageing on starch-based films plasticised by 1-ethyl-3-methylimidazolium acetate and by glycerol.

    PubMed

    Zhang, Binjia; Xie, Fengwei; Zhang, Tianlong; Chen, Ling; Li, Xiaoxi; Truss, Rowan W; Halley, Peter J; Shamshina, Julia L; McNally, Tony; Rogers, Robin D

    2016-08-01

    The focus of this study was on the effects of plasticisers (the ionic liquid 1-ethyl-3-methylimidazolium acetate, or [Emim][OAc]; and glycerol) on the changes of starch structure on multiple length scales, and the variation in properties of plasticised starch-based films, during ageing. The films were prepared by a simple melt compression moulding process, followed by storage at different relative humidity (RH) environments. Compared with glycerol, [Emim][OAc] could result in greater homogeneity in [Emim][OAc]-plasticised starch-based films (no gel-like aggregates and less molecular order (crystallites) on the nano-scale). Besides, much weaker starch-starch interactions but stronger starch-[Emim][OAc] interactions at the molecular level led to reduced strength and stiffness but increased flexibility of the films. More importantly, [Emim][OAc] (especially at high content) was revealed to more effectively maintain the plasticised state during ageing than glycerol: the densification (especially in the amorphous regions) was suppressed; and the structural characteristics especially on the nano-scale were stabilised (especially at a high RH), presumably due to the suppressed starch molecular interactions by [Emim][OAc] as confirmed by Raman spectroscopy. Such behaviour contributed to stabilised mechanical properties. Nonetheless, the crystallinity and thermal stability of starch-based films with both plasticisers were much less affected by ageing and moisture uptake during storage (42 days), but mostly depended on the plasticiser type and content. As starch is a typical semi-crystalline bio-polymer containing abundant hydroxyl groups and strong hydrogen bonding, the findings here could also be significant in creating materials from other similar biopolymers with tailored sensitivity and properties to the environment. PMID:27112852

  2. Pore-size dependent effects on structure and vibrations of 1-ethyl-3-methylimidazolium tetrafluoroborate in nanoporous carbon

    NASA Astrophysics Data System (ADS)

    Thürmer, Stephan; Kobayashi, Yoshikazu; Ohba, Tomonori; Kanoh, Hirofumi

    2015-09-01

    We report XRD and IR measurements of 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI-BF4) adsorbed in activated carbons, molecular sieving carbon, and single wall carbon nanohorn, where we specifically chose a wide range of pore sizes from 0.5 nm to 2.5 nm. Electron radial distribution function analysis reveals denser packing upon adsorption in two steps, for pore widths larger and comparable to the ion size. Average ion-distance was decreased by 0.05 nm in the latter case. With support of DFT calculations we identify a suppression of specific vibrational modes, which are interpreted as constrainment by the pore walls. Possible consequences for supercapacitor application are discussed.

  3. A new chemiluminescence method for determination of clonazepam and diazepam based on 1-Ethyl-3-Methylimidazolium Ethylsulfate/copper as catalyst

    NASA Astrophysics Data System (ADS)

    Chaichi, M. J.; Alijanpour, S. O.

    2014-01-01

    A novel chemiluminescence (CL) reaction, Benzodiazepines-H2O2-1-Ethyl-3-Methylimidazolium Ethylsulfate/copper, for determination of clonazepam and diazepam at nanogram per milliliter level in batch-type system have been described. The method relies on the catalytic effect of 1-Ethyl-3-Methylimidazolium Ethylsulfate/copper on the chemiluminescence reaction of Benzodiazepines, the oxidation of Benzodiazepines with hydrogen peroxide in natural medium. The influences of various experimental parameters such as solution pH, the ratio of 1-Ethyl-3 Methylimidazolium ethylsulfate concentration to copper ion, the type of buffer and the concentration of CL reagents were investigated. Under the optimum condition, the proposed method was satisfactorily applied for the determination of these drugs in tablets and urine without the interference of their potential impurities.

  4. A new chemiluminescence method for determination of clonazepam and diazepam based on 1-Ethyl-3-Methylimidazolium Ethylsulfate/copper as catalyst.

    PubMed

    Chaichi, M J; Alijanpour, S O

    2014-01-24

    A novel chemiluminescence (CL) reaction, Benzodiazepines-H2O2-1-Ethyl-3-Methylimidazolium Ethylsulfate/copper, for determination of clonazepam and diazepam at nanogram per milliliter level in batch-type system have been described. The method relies on the catalytic effect of 1-Ethyl-3-Methylimidazolium Ethylsulfate/copper on the chemiluminescence reaction of Benzodiazepines, the oxidation of Benzodiazepines with hydrogen peroxide in natural medium. The influences of various experimental parameters such as solution pH, the ratio of 1-Ethyl-3 Methylimidazolium ethylsulfate concentration to copper ion, the type of buffer and the concentration of CL reagents were investigated. Under the optimum condition, the proposed method was satisfactorily applied for the determination of these drugs in tablets and urine without the interference of their potential impurities. PMID:24036305

  5. The C-H bond activation in 1-ethyl-3-methylimidazolium acetate-copper(II) acetate-water-air (dioxygen) systems.

    PubMed

    Shtyrlin, Valery G; Serov, Nikita Yu; Islamov, Daut R; Konkin, Alexander L; Bukharov, Mikhail S; Gnezdilov, Oleg I; Krivolapov, Dmitry B; Kataeva, Ol'ga N; Nazmutdinova, Gulnara A; Wendler, Frank

    2014-01-14

    Ionic liquid (1-ethyl-3-methylimidazolium acetate, [C2C1im][AcO])-copper(ii) diacetate monohydrate-water-air (O2) systems have been investigated by (13)C NMR, EPR, spectrophotometry, HPLC, and synthetic chemistry methods at different temperatures. The C-H bond activation of [C2C1im](+) with the formation of the unusual dication 1,1'-diethyl-3,3'-dimethyl-2,2'-biimidazolium ([(C2C1im)2](2+)) at 50 °C and 1-ethyl-3-methyl-1H-imidazol-2(3H)-one (C2C1imO) at 50-85 °C was revealed. Two new complexes with the above compounds, [(C2C1im)2][Cu(AcO)4] and Cu2(AcO)4(C2C1imO)2, were isolated from the systems and characterized by X-ray structural analysis. Catalytic cycles with the participation of copper(ii) acetate and dioxygen and the production of [(C2C1im)2](2+) and C2C1imO have been proposed. The catalysis presumably includes the formation of the Cu(II)(O2)Cu(II) active centre with μ-η(2):η(2)-peroxide bridging in analogy with tyrosinase and catechol oxidase activity. PMID:24154681

  6. Comparative study of electron stimulated positive-ion desorption from LiCl and 1-ethyl-3-methylimidazolium bis[trifluoromethylsulfonyl]imide

    NASA Astrophysics Data System (ADS)

    Souda, Ryutaro

    2009-08-01

    The mechanism of electron stimulated desorption (ESD) from LiCl has been investigated in comparison with that from a room-temperature ionic liquid, 1-ethyl-3-methylimidazolium bis[trifluoromethylsulfonyl]imide, [emim][Tf2N]. The bonding natures of these materials are discussed based on the matrix effect in positive-ion yields. The [emim]+ and fragment ions are emitted from the [emim][Tf2N] molecule unless it is in direct contact with a metal surface, suggesting that the ions are emitted provided that the electronic excitation can be localized in each molecule. In contrast, the electronic excitation tends to be delocalized over the LiCl film, as evidenced by a monotonic increase of a Li+ yield in the multilayer regime. The Li+ ion is created via gas-phase ionization of desorbed neutrals or emitted directly from the surface, in which self-trapped excitons or hot carriers created in the bulk play a role. The Li+ and Li+(LiCl) ions are emitted efficiently from LiCl nanoclusters formed on a rare-gas solid film via Coulombic fission. The delocalized nature of hot holes is also manifested by steep decay of the ion yields with increasing LiCl coverage. The structural transformation of [emim][Tf2N] during the phase transition is also revealed based on ESD positive-ion yields as a function of temperature.

  7. Study of the mechanism for electrodeposition of dendrite-free zinc in an alkaline electrolyte modified with 1-ethyl-3-methylimidazolium dicyanamide

    NASA Astrophysics Data System (ADS)

    Xu, M.; Ivey, D. G.; Qu, W.; Xie, Z.

    2015-01-01

    Electrodeposition of Zn was conducted in a new electrolyte system composed of an alkaline solution (9 M KOH + 5 wt% ZnO) modified with a small amount (0.5 wt%) of room temperature ionic liquid 1-ethyl-3-methylimidazolium dicyanamide (EMI-DCA). At a high deposition current density of 80 mA cm-2, a porous, dendrite-free Zn film characterized by clusters of small Zn particles was obtained. The mechanism for the modified Zn morphology in the EMI-DCA containing electrolyte was studied by cyclic voltammetry, chronoamperometry, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy. It was found that the addition of EMI-DCA changed the Zn nucleation process and reduced the potential variation during electrodeposition, which suppressed the uneven growth of Zn deposits and the formation of Zn dendrites. EIS results indicated that there was adsorption of EMI+ cations at the Zn film/electrolyte interface, which may have contributed to suppressed dendritic Zn growth.

  8. Comparative study of electron stimulated positive-ion desorption from LiCl and 1-ethyl-3-methylimidazolium bis[trifluoromethylsulfonyl]imide.

    PubMed

    Souda, Ryutaro

    2009-08-28

    The mechanism of electron stimulated desorption (ESD) from LiCl has been investigated in comparison with that from a room-temperature ionic liquid, 1-ethyl-3-methylimidazolium bis[trifluoromethylsulfonyl]imide, [emim][Tf(2)N]. The bonding natures of these materials are discussed based on the matrix effect in positive-ion yields. The [emim](+) and fragment ions are emitted from the [emim][Tf(2)N] molecule unless it is in direct contact with a metal surface, suggesting that the ions are emitted provided that the electronic excitation can be localized in each molecule. In contrast, the electronic excitation tends to be delocalized over the LiCl film, as evidenced by a monotonic increase of a Li(+) yield in the multilayer regime. The Li(+) ion is created via gas-phase ionization of desorbed neutrals or emitted directly from the surface, in which self-trapped excitons or hot carriers created in the bulk play a role. The Li(+) and Li(+)(LiCl) ions are emitted efficiently from LiCl nanoclusters formed on a rare-gas solid film via Coulombic fission. The delocalized nature of hot holes is also manifested by steep decay of the ion yields with increasing LiCl coverage. The structural transformation of [emim][Tf(2)N] during the phase transition is also revealed based on ESD positive-ion yields as a function of temperature. PMID:19725616

  9. Influence of water on swelling and dissolution of cellulose in 1-ethyl-3-methylimidazolium acetate.

    PubMed

    Olsson, Carina; Idström, Alexander; Nordstierna, Lars; Westman, Gunnar

    2014-01-01

    In this study the effect of residual coagulation medium (water) on cellulose dissolution in an ionic liquid is discussed. Solubility of dissolving grade pulp; HWP and SWP, and microcrystalline cellulose in binary solvents, mixtures of 1-ethyl-3-methyl-imidazolium acetate and water, was investigated by turbidity measurements, light microscopy, rheometry, and CP/MAS (13)C-NMR spectroscopy. The viscoelastic properties of the cellulose solutions imply that residual water affect the cellulose dissolution. However, it is not obvious that this always necessarily poses serious drawbacks for the solution properties or that the effects are as severe as previously believed. Turbidity measurements, viscosity data and crystallinity of the regenerated cellulose correlated well and an increased conversion to cellulose II was found at low water and cellulose contents with an apparent maximum of conversion at 2-5 wt% water. At high water content, above 10 wt%, dissolution and conversion was largely inhibited. PMID:24274528

  10. Raman and FTIR spectroscopic studies of 1-ethyl-3-methylimidazolium trifluoromethylsulfonate, its mixtures with water and the solvation of zinc ions.

    PubMed

    Liu, Zhen; El Abedin, Sherif Zein; Endres, Frank

    2015-04-01

    In this paper we report on the interactions of the ionic liquid 1-ethyl-3-methylimidazolium trifluoromethylsulfonate ([EMIm]TfO) with water and the solvation of zinc ions in neat [EMIm]TfO and [EMIm]TfO-water mixtures investigated by FTIR and Raman spectroscopy. The structures and physicochemical properties of the [EMIm]TfO-water mixtures are strongly dependent on the interaction between cations, anions, and water. The structure was changed from ionic-liquid-like to water-like solutions upon addition of water. In addition, zinc salts can precipitate in 0.2 M Zn(TfO)2/[EMIm]TfO upon addition of 10 % (v/v) water, presumably as a result of polarity change of the solution. The average coordination number of TfO(-) per zinc ion calculated from Raman spectra is 3.8 in neat [EMIm]TfO, indicating that [Zn(TfO)4](2-), and [Zn(TfO)3](-) complexes are present in the solution. However, in the presence of water, water interacts preferentially with the zinc ions, leading to aqueous zinc species. The solvation of zinc ions in 1-butyl-1-methylpyrrolidinium trifluoromethylsulfonate ([Py(1,4)]TfO) was also investigated. In [Py(1,4)]TfO, there are, on average, 4.5 TfO(-) anions coordinating each zinc ion, corresponding to the weak interaction between [Py(1,4)](+) cations and TfO(-) anions. The species present in [Py(1,4)]TfO are likely a mixture of [Zn(TfO)4](2-) and [Zn(TfO)5](3-). PMID:25630920

  11. Insights on the solubility of CO2 in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide from the microscopic point of view.

    PubMed

    Lourenço, Tuanan C; Coelho, Mariny F C; Ramalho, Teodorico C; van der Spoel, David; Costa, Luciano T

    2013-07-01

    Emissions of greenhouse gases due to human activities have been well documented as well as the effects on global warming resulting from it. Efforts to reduce greenhouse gases at the source are crucial to curb climate change, but due to insignificant economic incentives to reduce usage of fossil fuels, not a lot of progress has been made by this route. This necessitates additional measures to reduce the occurrence of greenhouse gases in the atmosphere. Here we used theoretical methods to study the solubility of carbon dioxide in ionic liquids (ILs) since sequestration of CO2 in ILs has been proposed as a possible technology for reducing the emissions of CO2 to the atmosphere. Ionic liquids form a class of solvents with melting temperatures below 100 °C and, due to very low vapor pressures, which are not volatile. We have performed molecular dynamics (MD) simulations of 1-ethyl-3-methylimidazolium (C2mim) bis(trifluoromethylsulfonyl)imide (Tf2N) and its mixtures with carbon dioxide in order to investigate the CO2 concentration effect on the CO2-cation and CO2-anion interactions. A systematic investigation of CO2 concentration effects on resulting equilibrium liquid structure, and the local environment of the ions is provided. The Quantum Theory of Atoms in Molecules (QTAIM) was used to determine the interaction energy for CO2-cation and CO2-anion complexes from uncorrelated structures derived from MD simulations. A spatial distribution function analysis demonstrates the specific interactions between CO2 and the ionic liquid. Our findings indicate that the total volume of the system increases with the CO2 concentration, with a molar volume of CO2 of about 0.038 L/mol, corresponding to liquid CO2 under a pressure of 100 bar. In other words, the IL effectively pressurizes the CO2 inside its matrix. The thermodynamics of CO2 solvation in C2 min-Tf2N were computed using free energy techniques, and the solubility of CO2 is found to be higher in this IL (-3.7 ± 1 kcal

  12. Characterization of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][Tf2N])∕TX-100∕cyclohexane ternary microemulsion: investigation of photoinduced electron transfer in this RTIL containing microemulsion.

    PubMed

    Sarkar, Souravi; Pramanik, Rajib; Ghatak, Chiranjib; Rao, Vishal Govind; Sarkar, Nilmoni

    2011-02-21

    In this study we have characterized a ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethyl- sulfonyl)imide containing ternary nonaqueous microemulsion ([Emim][Tf(2)N]∕∕TX-100∕cyclo- hexane). The phase behavior and dynamic light scattering study show that the [Emim][Tf(2)N]∕TX-100∕cyclohexane three component system can form microemulsion with [Emim][Tf(2)N] as polar core at suitable condition. We have investigated photoinduced electron transfer (PET) using dimethyl aniline as electron donor and several Coumarin dyes as electron acceptor molecules at two different R values (R = [ionic liquid]∕[surfactant]) to observe how the dynamics of the PET rate is affected in this type of confined microenvironment compared to that of the PET dynamics in neat ionic liquid and other pure solvent media. The plot of observed k(q) values with the free energy change (ΔG(0)) for electron transfer reaction shows an apparent inversion in the observed rate as predicted by the Marcus theory. PMID:21341859

  13. Characterization of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][Tf2N])/TX-100/cyclohexane ternary microemulsion: Investigation of photoinduced electron transfer in this RTIL containing microemulsion

    NASA Astrophysics Data System (ADS)

    Sarkar, Souravi; Pramanik, Rajib; Ghatak, Chiranjib; Rao, Vishal Govind; Sarkar, Nilmoni

    2011-02-01

    In this study we have characterized a ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethyl- sulfonyl)imide containing ternary nonaqueous microemulsion ([Emim][Tf2N]//TX-100/cyclo- hexane). The phase behavior and dynamic light scattering study show that the [Emim][Tf2N]/TX-100/cyclohexane three component system can form microemulsion with [Emim][Tf2N] as polar core at suitable condition. We have investigated photoinduced electron transfer (PET) using dimethyl aniline as electron donor and several Coumarin dyes as electron acceptor molecules at two different R values (R = [ionic liquid]/[surfactant]) to observe how the dynamics of the PET rate is affected in this type of confined microenvironment compared to that of the PET dynamics in neat ionic liquid and other pure solvent media. The plot of observed kq values with the free energy change (ΔG0) for electron transfer reaction shows an apparent inversion in the observed rate as predicted by the Marcus theory.

  14. Investigation of Ternary Mixtures Containing 1-Ethyl-3-methylimidazolium Bis(trifluoromethanesulfonyl)azanide, Ethylene Carbonate and Lithium Bis(trifluoromethanesulfonyl)azanide.

    PubMed

    Hofmann, Andreas; Migeot, Matthias; Arens, Lukas; Hanemann, Thomas

    2016-01-01

    Temperature-dependent viscosity, conductivity and density data of ternary mixtures containing 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)azanide (EMIM-TFSA), ethylene carbonate (EC), and lithium bis(trifluoromethanesulfonyl)azanide (Li-TFSA) were determined at atmospheric pressure in the temperature range of 20 to 80 °C. Differential scanning calorimetry (DSC) measurements were performed to characterize phase conditions of the mixtures in a temperature range of -120 to +100 °C. The viscosity data were fitted according to the Vogel-Fulcher-Tammann-Hesse (VFTH) equation and analyzed with the help of the fractional Walden rule. In this study, fundamental physicochemical data about the mixtures are provided and discussed as a basis for structure-property relationship calculations and for potential use of those mixtures as electrolytes for various applications. PMID:27153066

  15. Investigation of Ternary Mixtures Containing 1-Ethyl-3-methylimidazolium Bis(trifluoromethanesulfonyl)azanide, Ethylene Carbonate and Lithium Bis(trifluoromethanesulfonyl)azanide

    PubMed Central

    Hofmann, Andreas; Migeot, Matthias; Arens, Lukas; Hanemann, Thomas

    2016-01-01

    Temperature-dependent viscosity, conductivity and density data of ternary mixtures containing 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)azanide (EMIM-TFSA), ethylene carbonate (EC), and lithium bis(trifluoromethanesulfonyl)azanide (Li-TFSA) were determined at atmospheric pressure in the temperature range of 20 to 80 °C. Differential scanning calorimetry (DSC) measurements were performed to characterize phase conditions of the mixtures in a temperature range of −120 to +100 °C. The viscosity data were fitted according to the Vogel-Fulcher-Tammann-Hesse (VFTH) equation and analyzed with the help of the fractional Walden rule. In this study, fundamental physicochemical data about the mixtures are provided and discussed as a basis for structure-property relationship calculations and for potential use of those mixtures as electrolytes for various applications. PMID:27153066

  16. Desulfurization of oxidized diesel using ionic liquids

    NASA Astrophysics Data System (ADS)

    Wilfred, Cecilia D.; Salleh, M. Zulhaziman M.; Mutalib, M. I. Abdul

    2014-10-01

    The extraction of oxidized sulfur compounds from diesel were carried out using ten types of ionic liquids consisting of different cation and anion i.e. 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazoium thiocyanate, 1-butyl-3-methylimidazoium dicyanamide, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazoliumhexafluorophosphate, 1-hexyl-3-methylimidazolium trifluoromethanesulfonate, trioctylmethylammonium chloride, 1-propionitrile-3-butylimidazolium thiocyanate, 1-propionitrile-3-butylimidazolium dicyanamide and 1-butyl-6-methylquinolinium dicyanamide. The oxidation of diesel was successfully done using phosphotungstic acid as the catalyst, hydrogen peroxide (H2O2) as the oxidant and trioctylmethylammonium chloride as the phase transfer agent. The oxidation of diesel changes the sulfur compounds into sulfone which increases its polarity and enhances the ionic liquid's extraction performance. Result showed that ionic liquid [C4mquin][N(CN)2] performed the highest sulfur removal (91% at 1:5 diesel:IL ratio) compared to the others.

  17. Electrolytic Conductivity of Four Imidazolium-Based Ionic Liquids

    NASA Astrophysics Data System (ADS)

    Calado, Marta S.; Diogo, João C. F.; Correia da Mata, José L.; Caetano, Fernando J. P.; Visak, Zoran P.; Fareleira, João M. N. A.

    2013-07-01

    In this article, electrolytic (ionic) conductivity measurements of four ionic liquids (ILs), namely, 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl] imide ([Cmim][NTf]), 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([Cmim][OTf]), 1-hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([Cmim][NTf]), and 1-ethyl-3-methylimidazolium ethyl sulfate ([Cmim][EtSO]) (ECOENG212), were performed in a temperature range of (288.15 to 333.15) K. [Cmim][NTf] was chosen to be a reference ionic liquid for several properties, including the electrolytic conductivity by the IUPAC Project 2002-005-1-100. For that reason, the measurements performed with that ionic liquid primarily serve the purpose to validate the instrumentation and the experimental procedure used in this work. The measurements were carried out using a complex impedance method, applying a novel electronic device designed and constructed for this purpose. The complete setup includes a Schott Instruments LF 913 T, used as a four-electrode conductivity cell, and a lock-in amplifier. The cell was calibrated using standard reference KCl aqueous solutions. The measurements of the impedance of the conductivity cell were carried out along a range of frequencies from (0.2 to 30) kHz, and the results were extrapolated to infinite frequency, in order to determine the electrolytic conductivity of the liquid samples. The results obtained for the ionic liquid [Cmim][NTf] were compared to reference data, and it was estimated that the overall uncertainty of the present results is better than 2 %. All the data obtained were compared with available literature data, and were analyzed and discussed in respect to the effect of temperature, cation alkyl chain length, and anion.

  18. Glycerol as an ionic liquid co-solvent for pretreatment of rice hulls to enhance glucose and xylose yield.

    PubMed

    Lynam, Joan G; Coronella, Charles J

    2014-08-01

    Rice hulls, a widely-available secondary agricultural residue, can be pretreated with ionic liquids (IL) prior to enzymatic hydrolysis to enhance glucose and xylose yields. The high cost of ILs is a deterrent to commercial deployment at present. ILs 1-ethyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium formate, 1,3-dimethylimidazolium dimethylphosphate, and 1-ethyl-3-methylimidazolium diethylphosphate were investigated for rice hull pretreatment. Effects of diluting ILs with glycerol were investigated for biomass pretreatment efficacy, and for solvent recovery. When diluted with 50% glycerol, rice hulls treated in 1-ethyl-3-methylimidazolium formate was found to give glucose and xylose yields after enzymatic hydrolysis better than rice hulls treated in pure 1-ethyl-3-methylimidazolium formate. Dilution in glycerol resulted in an increased rate of solvent recovery after pretreatment, as much as six times that when pure 1-ethyl-3-methylimidazolium formate was used. Diluting 1-ethyl-3-methylimidazolium formate with 50% glycerol was found to decrease solvent viscosity at the pretreatment temperature (110 °C) helping explain improved biomass pretreatment. PMID:24950092

  19. Enzyme activity in dialkyl phosphate ionic liquids.

    PubMed

    Thomas, Marie F; Li, Luen-Luen; Handley-Pendleton, Jocelyn M; van der Lelie, Daniel; Dunn, John J; Wishart, James F

    2011-12-01

    The activity of four metagenomic enzymes and an enzyme cloned from the straw mushroom, Volvariella volvacea were studied in the following ionic liquids, 1,3-dimethylimidazolium dimethyl phosphate, [mmim][dmp], 1-ethyl-3-methylimidazolium dimethyl phosphate, [emim][dmp], 1-ethyl-3-methylimidazolium diethyl phosphate, [emim][dep] and 1-ethyl-3-methylimidazolium acetate, [emim][OAc]. Activity was determined by analyzing the hydrolysis of para-nitrobenzene carbohydrate derivatives. In general, the enzymes were most active in the dimethyl phosphate ionic liquids, followed by acetate. Generally speaking, activity decreased sharply for concentrations of [emim][dep] above 10% v/v, while the other ionic liquids showed less impact on activity up to 20% v/v. PMID:22001053

  20. Enzyme activity in dialkyl phosphate ionic liquids

    SciTech Connect

    Thomas, M.F.; Dunn, J.; Li, L.-L.; Handley-Pendleton, J. M.; van der lelie, D.; Wishart, J. F.

    2011-12-01

    The activity of four metagenomic enzymes and an enzyme cloned from the straw mushroom, Volvariellavolvacea were studied in the following ionic liquids, 1,3-dimethylimidazolium dimethyl phosphate, [mmim][dmp], 1-ethyl-3-methylimidazolium dimethyl phosphate, [emim][dmp], 1-ethyl-3-methylimidazolium diethyl phosphate, [emim][dep] and 1-ethyl-3-methylimidazolium acetate, [emim][OAc]. Activity was determined by analyzing the hydrolysis of para-nitrobenzene carbohydrate derivatives. In general, the enzymes were most active in the dimethyl phosphate ionic liquids, followed by acetate. Generally speaking, activity decreased sharply for concentrations of [emim][dep] above 10% v/v, while the other ionic liquids showed less impact on activity up to 20% v/v.

  1. A new way to interpret perturbation-correlation moving-window two-dimensional correlation spectroscopy: probing the dynamic interaction of ionic liquid 1-ethyl-3-methylimidazolium acetate to absorb atmospheric water.

    PubMed

    Chen, Yu; Mu, Tiancheng

    2015-01-01

    A rule to interpret perturbation-correlation moving-window two-dimensional correlation spectroscopy (PCMW2D) was developed. Compared with Morita's rule, this proposed rule retains the ability to obtain interval features (i.e., monotonicity, concavity, and convexity) and adds the function to quickly and accurately determine both tipping points (i.e., local extrema and inflection points). It could be described as follows: the local extrema and inflection point could be determined by the zero point with an opposite sign on its left and right side in ΠΦ (synchronous PCMW2D) and ΠΨ (asynchronous PCMW2D), respectively. Specifically, a negative left (right) side and a positive right (left) side of point indicates a local minimal (maximal) value. By using the rule to interpret ΠIR (PCMW2D infrared spectroscopy) of 1-ethyl-3-methyl-imidazolium acetate [EMIM][Ac]-atmospheric water (H2O) as a function of time, we found that the atmospheric water was absorbed only into the bulk of [EMIM][Ac] before 150 min by hydrogen-bonding interaction, only onto the surface of [EMIM][Ac] after 330 min by van der Waals force, and both to the bulk and surface of [EMIM][Ac] between 150 and 330 min by hydrogen-boding and van der Waals force simultaneously. The proportion of bulk water sorption and surface water sorption to [EMIM][Ac] was about 4 and 96%, respectively. PMID:25280060

  2. Ionic liquids as novel solvents for ionic polymer transducers

    NASA Astrophysics Data System (ADS)

    Bennett, Matthew D.; Leo, Donald J.

    2004-07-01

    The use of ionic liquids as solvents for ionic polymer (specifically, Nafion) transducers is demonstrated. Ionic liquids are attractive for this application because of their high inherent stability. Ionic liquids are salts that exist as liquids at room temperature and have no measureable vapor pressure. Therefore, the use of ionic liquids as solvents for ionic polymer transducers can eliminate the traditional problem of water evaporation in these devices. Another benefit of the use of ionic liquids in this way is the reduction or elimination of the characteristic back-relaxation common in water-solvated ionic polymer actuators. The results demonstrate that the viscosity of the ionic liquid and the degree to which the ionic liquid swells the membrane are the important physical parameters to consider. Five ionic liquids were studied, based on substituted pyrrolidinium, phosphonium, or imidazolium cations and fluoroanions. Of these five ionic liquids, transduction is demonstrated in three of them and the best results are obtained with 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid. This substance has an electrochemical stability window of 4.1 V, a melting point of -10 °C, and a viscosity of 35-45 cP [19]. Results demonstrate that platinum-plated Nafion transducers solvated with this ionic liquid exhibit sensing and actuation responses and that these transducers are stable in air. Endurance testing of this sample reveals a decrease in the free strain of only 25 % after 250,000 actuation cycles in air.

  3. Genome Sequence of Halomonas sp. Strain KO116, an Ionic Liquid-Tolerant Marine Bacterium Isolated from a Lignin-Enriched Seawater Microcosm.

    PubMed

    O'Dell, Kaela B; Woo, Hannah L; Utturkar, Sagar; Klingeman, Dawn; Brown, Steven D; Hazen, Terry C

    2015-01-01

    Halomonas sp. strain KO116 was isolated from Nile Delta Mediterranean Sea surface water enriched with insoluble organosolv lignin. It was further screened for growth on alkali lignin minimal salts medium agar. The strain tolerates the ionic liquid 1-ethyl-3-methylimidazolium acetate. Its complete genome sequence is presented in this report. PMID:25953187

  4. Genome Sequence of Halomonas sp. Strain KO116, an Ionic Liquid-Tolerant Marine Bacterium Isolated from a Lignin-Enriched Seawater Microcosm

    PubMed Central

    O’Dell, Kaela B.; Woo, Hannah L.; Utturkar, Sagar; Klingeman, Dawn; Brown, Steven D.

    2015-01-01

    Halomonas sp. strain KO116 was isolated from Nile Delta Mediterranean Sea surface water enriched with insoluble organosolv lignin. It was further screened for growth on alkali lignin minimal salts medium agar. The strain tolerates the ionic liquid 1-ethyl-3-methylimidazolium acetate. Its complete genome sequence is presented in this report. PMID:25953187

  5. Genome Sequence of Halomonas sp. Strain KO116, an Ionic Liquid- Tolerant Marine Bacterium Isolated from a Lignin-Enriched Seawater Microcosm

    DOE PAGESBeta

    O'Dell, Kaela; Woo, Hannah L.; Utturkar, Sagar M.; Klingeman, Dawn Marie; Brown, Steven D.; Hazen, Terry C.

    2015-05-07

    Halomonas sp. strain KO116 was isolated from Nile Delta Mediterranean Sea surface water enriched with insoluble organosolv lignin. It was further screened for growth on alkali lignin minimal salts medium agar. The strain tolerates the ionic liquid 1-ethyl-3-methylimidazolium acetate. Its complete genome sequence is presented in this report.

  6. Transports of ionic liquids in ionic polymer conductor network composite actuators

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Liu, Sheng; Lin, Junhong; Wang, Dong; Jain, Vaibhav; Montazami, Reza; Heflin, James R.; Li, Jing; Madsen, Louis; Zhang, Q. M.

    2010-04-01

    We investigate the influence of ionic liquids on the electromechanical performance of Ionic Polymer Conductor Network Composite (IPCNC) bending actuators. Two imidazolium ionic liquids (ILs) with one cation, which is 1-ethyl-3- methylimidazolium ([EMI+]), and two different anions, which are tetrafluoroborate ([BF4-]) and trifluoromethanesulfonate ([Tf-]), are chosen for the study. By combining the time domain electric and electromechanical responses, we developed a new model that describes the ion transports in IPCNC actuators. The time constant of excess cation and anion migration in various composite electrodes are deduced: 6s and 25s in RuO2/Nafion; 7.9s and 36.3s in RuO2/Aquivion; 4.8s and 53s in Au/PAH, respectively. NMR is also applied to provide quantitative measures of self-diffusion coefficients independently for IL anions and cations both in pure ILs and in ILs absorved into ionomers. All the results indicate that the motion of cation, in the studied pure ionic liquids, polymer matrix and conductor network composites, is faster than that of anion. Moreover, the CNC morphology is playing a crucial role in determining the ion transport in the porous electrodes.

  7. Properties of an ionic liquid-tolerant Bacillus amyloliquefaciens CMW1 and its extracellular protease.

    PubMed

    Kurata, Atsushi; Senoo, Humiya; Ikeda, Yasuyuki; Kaida, Hideaki; Matsuhara, Chiaki; Kishimoto, Noriaki

    2016-07-01

    An ionic liquid-tolerant bacterium, Bacillus amyloliquefaciens CMW1, was isolated from a Japanese fermented soybean paste. Strain CMW1 grew in the presence of 10 % (v/v) 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), a commonly used ionic liquid. Additionally, strain CMW1 grew adequately in the presence of the hydrophilic ionic liquids 10 % (v/v) 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM]CF3SO3) or 2.5 % (v/v) 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([BMIM]CF3SO3). Strain CMW1 produced an extracellular protease (BapIL) in the culture medium. BapIL was stable in the presence of 80 % (v/v) ionic liquids, [EMIM]CF3SO3, [BMIM]Cl, [BMIM]CF3SO3, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate, and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and functioned in 10 % (v/v) these ionic liquids. BapIL was stable at pH 4.0-12.6 or in 4004 mM NaCl solution, and exhibited activity in the presence of 50 % (v/v) hydrophilic or hydrophobic organic solvents. BapIL was completely inhibited by 1 mM PMSF and partially by 5 mM EDTA. BapIL belongs to the true subtilisins according to analysis of the deduced amino acid sequence. We showed that BapIL from the ionic liquid-tolerant B. amyloliquefaciens CMW1 exhibited tolerance to ionic liquid and halo, alkaline, and organic solvents. PMID:27142029

  8. Ionic Liquid assisted Synthesis of Zeolite-TON

    PubMed Central

    Tian, Yuyang; McPherson, Matthew J; Wheatley, Paul S; Morris, Russell E

    2014-01-01

    An ionic liquid assisted strategy for the synthesis of zeolitic material is reported. This strategy is a solid state synthetic method and the ionic liquid is employed as structure directing agent. A TON-type zeolite, which contains one-dimensional 10-member-ring, is successfully synthesized with the assistance of the ionic liquid, 1-ethyl-3-methylimidazolium bromide. This finding improves our understanding about the challenge of ionothermally synthesizing siliceous and aluminosilicate zeolites. PMID:26213423

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

    PubMed

    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

  10. Thermal decomposition of carboxylate ionic liquids: trends and mechanisms.

    PubMed

    Clough, Matthew T; Geyer, Karolin; Hunt, Patricia A; Mertes, Jürgen; Welton, Tom

    2013-12-21

    The thermal stability of a series of dialkylimidazolium carboxylate ionic liquids has been investigated using a broad range of experimental and computational techniques. Ionic liquids incorporating fluoroalkyl carboxylate anions were found to have profoundly differing thermal stabilities and decomposition mechanisms compared with their non-fluorinated analogues. 1-Ethyl-3-methylimidazolium acetate was observed to largely decompose via an S(N)2 nucleophilic substitution reaction when under inert gas conditions, predominantly at the imidazolium methyl substituent. The Arrhenius equations for thermal decomposition of 1-ethyl-3-methylimidazolium acetate, and the C(2)-methylated analogue 1-ethyl-2,3-dimethylimidazolium acetate, were determined from isothermal Thermogravimetric Analysis experiments. The low thermal stability of 1-ethyl-3-methylimidazolium acetate has important implications for biomass experiments employing this ionic liquid. For these two ionic liquids, ion pair and transition state structures were optimised using Density Functional Theory. The activation barriers for the S(N)2 nucleophilic substitution mechanisms are in good agreement with the experimentally determined values. PMID:24173605

  11. Accurate measurements of thermodynamic properties of solutes in ionic liquids using inverse gas chromatography.

    PubMed

    Mutelet, Fabrice; Jaubert, Jean-Noël

    2006-01-13

    Activity coefficients at infinite dilution of 29 organic compounds in two room temperature ionic liquids were determined using inverse gas chromatography. The measurements were carried out at different temperatures between 323.15 and 343.15K. To establish the influence of concurrent retention mechanisms on the accuracy of activity coefficients at infinite dilution for 1-butyl-3-methylimidazolium octyl sulfate and 1-ethyl-3-methylimidazolium tosylate, phase loading studies of the net retention volume per gram of packing as a function of the percent phase loading were used. It is shown that most of the solutes are retained largely by partition with a small contribution from adsorption on 1-butyl-3-methylimidazolium octyl sulfate and that the n-alkanes are retained predominantly by interfacial adsorption on 1-ethyl-3-methylimidazolium tosylate. PMID:16310203

  12. Ultrasound-assisted green synthesis of nanocrystalline Co{sub 3}O{sub 4} in the ionic liquid

    SciTech Connect

    Al-Qirby, Lamya M.; Radiman, Shahidan

    2014-09-03

    Cobalt oxide Co{sub 3}O{sub 4} nanoparticles have been synthesized via sonochemical method in an ionic liquid, 1-Ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF4] for the first time. The crystal structure of Co{sub 3}O{sub 4} nanoparticles has been characterized by using powder X-ray diffraction (XRD). Morphology has been characterized by transmission electron microscopy (TEM). The optical properties were studied by UV-VIS Spectrometer.

  13. Partition coefficients of organic compounds in new imidazolium based ionic liquids using inverse gas chromatography.

    PubMed

    Revelli, Anne-Laure; Mutelet, Fabrice; Jaubert, Jean-Noël

    2009-06-01

    Partition coefficients of organic compounds in four ionic liquids: 1-ethanol-3-methylimidazolium tetrafluoroborate, 1-ethanol-3-methylimidazolium hexafluorophosphate, 1,3-dimethylimidazolium dimethylphosphate and 1-ethyl-3-methylimidazolium diethylphosphate were measured using inverse gas chromatography from 303.3 to 332.55K. The influence of gas-liquid and gas-solid interfacial adsorption of different solutes on ionic liquids was also studied. Most of the polar solutes were retained largely by partition while light hydrocarbons were retained predominantly by interfacial adsorption on the ionic liquids studied in this work. The solvation characteristics of the ionic liquids were evaluated using the Abraham solvation parameter model. PMID:19414174

  14. Increasing the intensity of protonated secondary ions in time-of-flight secondary ion mass spectrometry using a proton-conducting ionic liquid, diethylmethylammonium trifluoromethanesulfonate

    NASA Astrophysics Data System (ADS)

    Fujiwara, Yukio; Saito, Naoaki

    2015-07-01

    To increase the secondary ion intensities of organic molecules, room-temperature ionic liquids were investigated in two time-of-flight secondary ion mass spectrometry (TOF-SIMS) experiments. First, ionic liquids as well as glycerol were tested as liquid matrices of arginine. The secondary ion intensity of protonated arginine was increased 200-fold by using a proton-conducting ionic liquid, diethylmethylammonium trifluoromethanesulfonate ([dema][TfO]). The matrix effect of [dema][TfO] was higher than that of glycerol, which is a typical matrix in SIMS. Next, ionic liquids were tested as primary ion beams. The number of protonated secondary ions of arginine was significantly increased by using a primary ion beam of [dema][TfO].

  15. Tandem dissolution of UO 3 in amide-based acidic ionic liquid and in situ electrodeposition of UO 2 with regeneration of the ionic liquid: a closed cycle

    DOE PAGESBeta

    Wanigasekara, Eranda; Freiderich, John W.; Sun, Xiao-Guang; Meisner, Roberta A.; Luo, Huimin; Delmau, Lætitia H.; Dai, Sheng; Moyer, Bruce A.

    2016-05-19

    A closed cycle is demonstrated for the tandem dissolution and electroreduction of UO3 to UO2 with regeneration of the acidic ionic liquid. The dissolution is achieved by use of the acidic ionic liquid N,N-dimethylacetimidium bis(trifluoromethanesulfonimide) in 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonimide) serving as the diluent. Bulk electrolysis performed at 1.0 V vs. Ag reference yields a dark brown-black uranium deposit (UO2) on the cathode. Anodic oxidation of water in the presence of dimethylacetamide regenerates the acidic ionic liquid. We have demonstrated the individual steps in the cycle together with a sequential dissolution, electroreduction, and regeneration cycle.

  16. Synthesis of cellulose methylcarbonate in ionic liquids using dimethylcarbonate.

    PubMed

    Labafzadeh, Sara R; Helminen, K Juhani; Kilpeläinen, Ilkka; King, Alistair W T

    2015-01-01

    Dialkylcarbonates are viewed as low-cost, low-toxicity reagents, finding application in many areas of green chemistry. Homogeneous alkoxycarbonylation of cellulose was accomplished by applying dialkycarbonates (dimethyl and diethyl carbonate) in the ionic liquid-electrolyte trioctylphosphonium acetate ([P8881 ][OAc])/DMSO or 1-ethyl-3-methylimidazolium acetate ([emim][OAc]). Cellulose dialkylcarbonates with a moderate degree of substitution (DS∼1) are accessible via this procedure and cellulose methylcarbonate was thoroughly characterized for its chemical and physical properties after regeneration. This included HSQC & HMBC NMR, ATR-IR, molecular weight distribution, morphology, thermal properties, and barrier properties after film formation. PMID:25378289

  17. The force field for imidazolium-based ionic liquids: Novel anions with polar residues

    NASA Astrophysics Data System (ADS)

    Fileti, Eudes Eterno; Chaban, Vitaly V.

    2015-07-01

    Many molecules can be converted into ions via relatively simple procedures. These ions can be combined into ionic liquids (ILs). We develop a new force field (FF) for the seven selected AAILs comprising 1-ethyl-3-methylimidazolium cation and amino acid anions with polar residues. All anions were obtained via deprotonation of carboxyl group in analogy with acetate anion. We account for peculiar interactions between the anion and the cation by fitting electrostatic potential for an ion pair, in contrast to isolated ions. Furthermore, we account for hydrogen bonds obtained via electronic structure consideration. The developed model fosters computational investigation of ionic liquids.

  18. Ion segregation in an ionic liquid confined within chitosan based chemical ionogels.

    PubMed

    Guyomard-Lack, A; Buchtová, N; Humbert, B; Le Bideau, J

    2015-10-01

    Ionogels based on in situ crosslinking of chitosan in the ionic liquid 1-ethyl-3-methylimidazolium acetate (EMIm Ac) are synthesized, and studied from macroscopic properties to preferred interactions at the host matrix/EMIm Ac interface. It is highlighted that the imidazolium cations of the ionic liquid (IL) show preferred interactions with the chitosan host matrix. This exemplifies how the confinement of ILs, through an interface effect, can induce the breakdown of aggregated regions found systematically in bulk ILs and can increase the fragility of ILs. These biopolymer based ionogels could find application as biosensors and in the field of energy. PMID:26313702

  19. Lithium-air batteries using hydrophobic room temperature ionic liquid electrolyte

    NASA Astrophysics Data System (ADS)

    Kuboki, Takashi; Okuyama, Tetsuo; Ohsaki, Takahisa; Takami, Norio

    Lithium-air batteries using hydrophobic ionic liquid consisting of 1-alkyl-3-methyl imidazolium cation and perfluoroalkylsulfonyl imide anion were investigated. 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, which has high conductivity and prevents hydrolysis of the lithium anode, showed the best electrolyte performance. The cell worked for 56 days in air, and the cathode carbon materials showed high discharge capacity of 5360 mAh g -1. In addition to hydrophobic ionic liquids for use as electrolytes, various carbon materials for use as high-capacity cathodes were investigated.

  20. Electrochemical synthesis and surface characterization of poly(3,4-ethylenedioxythiophene) films grown in an ionic liquid.

    PubMed

    Ahmad, Shahzada; Deepa, M; Singh, S

    2007-11-01

    We report a facile method to synthesize poly(3,4-ethylenedioxythiophene) (PEDOT) films at room temperature in a waterproof ionic liquid, 1-ethyl-3-methylimidazolium bis(perfluoroethylsulfonyl)imide (EMIPFSI), by electropolymerization. The ionic liquid leads to the formation of randomly oriented nanofibers and particles confined to submicrometer-sized domains in the film microstructure. X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray (EDX) studies provide information about the intercalation of the cation apart from the reported anion in the polymer film, and on how the imidazolium ion controls the growth of PEDOT nanostructures. PMID:17915903

  1. Synthesis in ionic liquids : [Bi{sub 2}Te{sub 2}Br](AlCl{sub 4}), a direct gap semiconductor with a cationic framework.

    SciTech Connect

    Biswas, K.; Zhang, Q.; Chung, I.; Song, J.-H.; Androulaksi, J.; Freeman, A. J.; Kanatzidis, M. G.; Materials Science Division; Northwestern Univ.

    2010-01-01

    The Lewis acidic ionic liquid EMIMBr-AlCl{sub 3} (EMIM = 1-ethyl-3-methylimidazolium) allows a novel synthetic route to the semiconducting layered metal chalcogenides halide [Bi{sub 2}Te{sub 2}Br](AlCl{sub 4}) and its Sb analogue. [Bi{sub 2}Te{sub 2}Br](AlCl{sub 4}) is a direct band gap, strongly anisotropic semiconductor and consists of cationic infinite layers of [Bi{sub 2}Te{sub 2}Br]{sup +} and [AlCl{sub 4}]{sup -} anions inserted between the layers.

  2. Global transcriptome response to ionic liquid by a tropical rain forest soil bacterium, Enterobacter lignolyticus.

    PubMed

    Khudyakov, Jane I; D'haeseleer, Patrik; Borglin, Sharon E; Deangelis, Kristen M; Woo, Hannah; Lindquist, Erika A; Hazen, Terry C; Simmons, Blake A; Thelen, Michael P

    2012-08-01

    To process plant-based renewable biofuels, pretreatment of plant feedstock with ionic liquids has significant advantages over current methods for deconstruction of lignocellulosic feedstocks. However, ionic liquids are often toxic to the microorganisms used subsequently for biomass saccharification and fermentation. We previously isolated Enterobacter lignolyticus strain SCF1, a lignocellulolytic bacterium from tropical rain forest soil, and report here that it can grow in the presence of 0.5 M 1-ethyl-3-methylimidazolium chloride, a commonly used ionic liquid. We investigated molecular mechanisms of SCF1 ionic liquid tolerance using a combination of phenotypic growth assays, phospholipid fatty acid analysis, and RNA sequencing technologies. Potential modes of resistance to 1-ethyl-3-methylimidazolium chloride include an increase in cyclopropane fatty acids in the cell membrane, scavenging of compatible solutes, up-regulation of osmoprotectant transporters and drug efflux pumps, and down-regulation of membrane porins. These findings represent an important first step in understanding mechanisms of ionic liquid resistance in bacteria and provide a basis for engineering microbial tolerance. PMID:22586090

  3. Chalcogenide chemistry in ionic liquids: nonlinear optical wave-mixing properties of the double-cubane compound [Sb{sub 7}S{sub 8}Br{sub 2}](AlCl{sub 4}){sub 3}.

    SciTech Connect

    Zhang, Q.; Chung, I.; Jang, J. I.; Ketterson, J. B.; Kanatzidis, M. G.

    2009-07-06

    The new cation [Sb{sub 7}S{sub 8}Br{sub 2}]{sup 3+} has a double-cubane structure and forms as the [AlCl{sub 4}]{sup -} salt from the ionic liquid EMIMBr-AlCl{sub 3} (EMIM = 1-ethyl-3-methylimidazolium) at 165 C. The compound is noncentrosymmetric with space group P2{sub 1}2{sub 1}2{sub 1} and exhibits second-harmonic and difference-frequency nonlinear optical response across a wide range of the visible and near-infrared regions.

  4. Solvent effects on the polar network of ionic liquid solutions

    NASA Astrophysics Data System (ADS)

    Bernardes, Carlos E. S.; Shimizu, Karina; Canongia Lopes, José N.

    2015-05-01

    Molecular dynamics simulations were used to probe mixtures of ionic liquids (ILs) with common molecular solvents. Four types of systems were considered: (i) 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide plus benzene, hexafluorobenzene or 1,2-difluorobenzene mixtures; (ii) choline-based ILs plus ether mixtures (iii) choline-based ILs plus n-alkanol mixtures; and (iv) 1-butyl-3-methylimidazolium nitrate and 1-ethyl-3-methylimidazolium ethyl sulfate aqueous mixtures. The results produced a wealth of structural and aggregation information that highlight the resilience of the polar network of the ILs (formed by clusters of alternating ions and counter-ions) to the addition of different types of molecular solvent. The analysis of the MD data also shows that the intricate balance between different types of interaction (electrostatic, van der Waals, H-bond-like) between the different species present in the mixtures has a profound effect on the morphology of the mixtures at a mesoscopic scale. In the case of the IL aqueous solutions, the present results suggest an alternative interpretation for very recently published x-ray and neutron diffraction data on similar systems.

  5. Solvent effects on the polar network of ionic liquid solutions.

    PubMed

    Bernardes, Carlos E S; Shimizu, Karina; Canongia Lopes, José N

    2015-05-20

    Molecular dynamics simulations were used to probe mixtures of ionic liquids (ILs) with common molecular solvents. Four types of systems were considered: (i) 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide plus benzene, hexafluorobenzene or 1,2-difluorobenzene mixtures; (ii) choline-based ILs plus ether mixtures (iii) choline-based ILs plus n-alkanol mixtures; and (iv) 1-butyl-3-methylimidazolium nitrate and 1-ethyl-3-methylimidazolium ethyl sulfate aqueous mixtures. The results produced a wealth of structural and aggregation information that highlight the resilience of the polar network of the ILs (formed by clusters of alternating ions and counter-ions) to the addition of different types of molecular solvent. The analysis of the MD data also shows that the intricate balance between different types of interaction (electrostatic, van der Waals, H-bond-like) between the different species present in the mixtures has a profound effect on the morphology of the mixtures at a mesoscopic scale. In the case of the IL aqueous solutions, the present results suggest an alternative interpretation for very recently published x-ray and neutron diffraction data on similar systems. PMID:25923649

  6. Alkyl-methylimidazolium ionic liquids affect the growth and fermentative metabolism of Clostridium sp

    SciTech Connect

    Nancharaiah, Y.V.; Francis, A.

    2011-06-01

    In this study, the effect of ionic liquids, 1-ethyl-3-methylimidazolium acetate [EMIM][Ac], 1-ethyl-3-methylimidazolium diethylphosphate [EMIM][DEP], and 1-methyl-3-methylimidazolium dimethylphosphate [MMIM][DMP] on the growth and glucose fermentation of Clostridium sp. was investigated. Among the three ionic liquids tested, [MMIM][DMP] was found to be least toxic. Growth of Clostridium sp. was not inhibited up to 2.5, 4 and 4 g L{sup -1} of [EMIM][Ac], [EMIM][DEP] and [MMIM][DMP], respectively. [EMIM][Ac] at <2.5 g L{sup -1}, showed hormetic effect and stimulated the growth and fermentation by modulating medium pH. Total organic acid production increased in the presence of 2.5 and 2 g L{sup -1} of [EMIM][Ac] and [MMIM][DMP]. Ionic liquids had no significant influence on alcohol production at <2.5 g L{sup -1}. Total gas production was affected by ILs at {ge}2.5 g L{sup -1} and varied with type of methylimidazolium IL. Overall, the results show that the growth and fermentative metabolism of Clostridium sp. is not impacted by ILs at concentrations below 2.5 g L{sup -1}.

  7. Influences of porous reservoir Laplace pressure on emissions from passively fed ionic liquid electrospray sources

    SciTech Connect

    Courtney, Daniel G. Shea, Herbert

    2015-09-07

    Passively fed ionic liquid electrospray sources are capable of efficiently emitting a variety of ion beams with promising applications to spacecraft propulsion and as focused ion beams. Practical devices will require integrated or coupled ionic liquid reservoirs; the effects of which have not been explored in detail. Porous reservoirs are a simple, scalable solution. However, we have shown that their pore size can dramatically alter the beam composition. Emitting the ionic liquid 1-ethyl-3-methylimidazolium bis(triflouromethylsulfonyl)amide, the same device was shown to yield either an ion or droplet dominated beam when using reservoirs of small or large pore size, respectively; with the latter having a mass flow in excess of 15 times larger than the former at negative polarity. Another source, emitting nearly purely ionic beams of 1-ethyl-3-methylimidazolium tetrafluoroborate, was similarly shown to emit a significant droplet population when coupled to reservoirs of large (>100 μm) pores; constituting a reduction in propulsive efficiency from greater than 70% to less than 30%. Furthermore, we show that reservoir selection can alter the voltage required to obtain and sustain emission, increasing with smaller pore size.

  8. Influences of porous reservoir Laplace pressure on emissions from passively fed ionic liquid electrospray sources

    NASA Astrophysics Data System (ADS)

    Courtney, Daniel G.; Shea, Herbert

    2015-09-01

    Passively fed ionic liquid electrospray sources are capable of efficiently emitting a variety of ion beams with promising applications to spacecraft propulsion and as focused ion beams. Practical devices will require integrated or coupled ionic liquid reservoirs; the effects of which have not been explored in detail. Porous reservoirs are a simple, scalable solution. However, we have shown that their pore size can dramatically alter the beam composition. Emitting the ionic liquid 1-ethyl-3-methylimidazolium bis(triflouromethylsulfonyl)amide, the same device was shown to yield either an ion or droplet dominated beam when using reservoirs of small or large pore size, respectively; with the latter having a mass flow in excess of 15 times larger than the former at negative polarity. Another source, emitting nearly purely ionic beams of 1-ethyl-3-methylimidazolium tetrafluoroborate, was similarly shown to emit a significant droplet population when coupled to reservoirs of large (>100 μm) pores; constituting a reduction in propulsive efficiency from greater than 70% to less than 30%. Furthermore, we show that reservoir selection can alter the voltage required to obtain and sustain emission, increasing with smaller pore size.

  9. Temperature-programed time-of-flight secondary ion mass spectrometry study of 1-butyl-3-methylimidazolium trifluoromethanesulfonate during glass-liquid transition, crystallization, melting, and solvation

    SciTech Connect

    Souda, Ryutaro; Guenster, Jens

    2008-09-07

    For this study, time-of-flight secondary ion mass spectrometry was used to analyze the molecular orientation of 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([bmim][OTf]) and its interaction with the adsorbed Na and LiI species at temperatures of 150-300 K. A glassy [bmim][OTf] film crystallizes at around 230 K, as observed from the increase in the [bmim]{sup +} yield. LiI and Na adsorbed on the glassy film are solvated, whereas they tend to form islands on a crystalline film. The crystalline surface inertness is ascribable to the termination with the CF{sub 3} and C{sub 4}H{sub 9} groups, whereas the exposure of polar SO{sub 3} and imidazole groups at the glassy film results in the solvation. Surface layering occurs during solvation of LiI on the glassy film in such a way that the [bmim]{sup +} ([OTf]{sup -}) moiety is exposed to the vacuum (oriented to the bulk). The LiI adsorbed on the glassy film is incorporated into the bulk at temperatures higher than 200 K because of the glass-liquid transition. No further uptake of LiI is observed during crystallization, providing a contrast to the results of normal molecular solids such as water and ethanol. The surface layers of the crystal melt at temperatures below the bulk melting point, as confirmed from the dissolution of adsorbed LiI, but the melting layer retains a short-range order similar to the crystal. The [bmim][OTf] can be regarded as a strongly correlated liquid with the combined liquid property and crystal-type local structure. The origin of this behavior is discussed.

  10. Comparison of different ionic liquids pretreatment for corn stover enzymatic saccharification.

    PubMed

    Mood, Sohrab Haghighi; Golfeshan, Amir Hossein; Tabatabaei, Meisam; Abbasalizadeh, Saeed; Ardjmand, Mehdi; Jouzani, Gholamreza Salehi

    2014-01-01

    Recently, application of ionic liquids (ILs) has received much attention due to their special solvency properties as a promising method of pretreatment for lignocellulosic biomass. Easy recovery of ionic liquids, chemical stability, temperature stability, nonflammability, low vapor pressure, and wide liquidus range are among those unique properties. These solvents are also known as green solvents due to their low vapor pressure. The present study was set to compare the effect of five different ILs, namely, 1-ethyl-3-methylimidazolium acetate ([EMIM][Ac]), 1-butyl-3-methylimidazolium chloride ([BMIM][Cl]), 1-ethyl-3-methyl imidazolium diethyl phosphate ([EMIM][DEP]), 1-allyl-3-methylimidazolium chloride ([AMIM][Cl]), and 1-ethyl-3-methylimidazolium-hydrogen sulfate ([EMIM][HSO₄]), on corn stover in a bioethanol production process. The performance of ILs was evaluated based on the change observed in chemical structure, crystallinity index, cellulose digestibility, and glucose release. Overall, [EMIM][Ac]-pretreated corn stover led to significantly higher saccharification, with cellulose digestibility reaching 69% after 72 hr, whereas digestibility of untreated barley straw was measured at only 21%. PMID:24397717

  11. Use of polyoxometalate catalysts in ionic liquids to enhance the dissolution and delignification of woody biomass.

    PubMed

    Sun, Ning; Jiang, Xinyu; Maxim, Mirela L; Metlen, Andreas; Rogers, Robin D

    2011-01-17

    A well-known polyoxometalate, [PV₂Mo₁₀O₄₀]⁵⁻, in both acidic (acidic POM, H₅[PV₂Mo₁₀O₄₀]) and ionic liquid-compatible form ([C₂mim]POM, [1-ethyl-3-methylimidazolium]₄H[PV₂Mo₁₀O₄₀]), has been studied as a catalyst for the dissolution and delignification of wood in the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate ([C(2) mim]OAc). Differences were observed with variables such as the form of POM, POM loading, and reaction conditions. Generally, the addition of POM leads to a faster dissolution, a lower lignin content in the recovered cellulose-rich materials (isolated pulp), and a lower isolated yield of lignin due to its oxidation. Acidic POM decreases the lignin content of the pulp without compromising the yield of the pulp. [C₂mim]POM in the IL facilitates greater delignification (lower lignin content in pulp) than the IL with acidic POM; however, the overall pulp yield is also lower indicating some degradation of the carbohydrates. The POM can be recovered with [C₂mim]OAc after evaporation of the reconstitution solvent (e.g., acetone/water) and can be reused, albeit with some loss of POM and loss of POM activity under the current conditions. PMID:21226213

  12. Electronically and ionically conductive gels of ionic liquids and charge-transfer tetrathiafulvalene-tetracyanoquinodimethane.

    PubMed

    Mei, Xiaoguang; Ouyang, Jianyong

    2011-09-01

    Electronically and ionically conductive gels were fabricated by mixing and mechanically grinding neutral tetrathiafulvalene (TTF) and tetracyanoquinodimethane (TCNQ) in ionic liquids (ILs) like 3-ethyl-1-methylimidazolium dicyanoamide (EMIDCA), 1-ethyl-3-methylimidazolium thiocyanate (EMISCN), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMITf(2)N), trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide (P(14,6,6,6)Tf(2)N), and methyl-trioctylammonium bis(trifluoromethylsulfonyl)imide (MOATf(2)N). Charge-transfer TTF-TCNQ crystallites were generated during the mechanical grinding as indicated by the UV-visibile-near-infrared (UV-vis-NIR) absorption spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction. The charge-transfer TTF-TCNQ crystallites have a needle-like shape. They form solid networks to gelate the ILs. The gel behavior is confirmed by the dynamic mechanical measurements. It depends on both the anions and cations of the ILs. In addition, when 1-methyl-3-butylimidazolium tetrafluoroborate (BMIBF(4)) and 1-methyl-3-propylimidazolium iodide (PMII) were used, the TTF-TCNQ/IL mixtures did not behave as gels. The TTF-TCNQ/IL gels are both electronically and ionically conductive, because the solid phase formed by the charge-transfer TTF-TCNQ crystallites is electronically conductive, while the ILs are ionically conductive. The gel formation is related to needle-like charge-transfer TTF-TCNQ cyrstallites and the π-π and Coulombic interactions between TTF-TCNQ and ILs. PMID:21800893

  13. Dissolving process of a cellulose bunch in ionic liquids: a molecular dynamics study.

    PubMed

    Li, Yao; Liu, Xiaomin; Zhang, Suojiang; Yao, Yingying; Yao, Xiaoqian; Xu, Junli; Lu, Xingmei

    2015-07-21

    In recent years, a variety of ionic liquids (ILs) were found to be capable of dissolving cellulose and mechanistic studies were also reported. However, there is still a lack of detailed information at the molecular level. Here, long time molecular dynamics simulations of cellulose bunch in 1-ethyl-3-methylimidazolium acetate (EmimAc), 1-ethyl-3-methylimidazolium chloride (EmimCl), 1-butyl-3-methylimidazolium chloride (BmimCl) and water were performed to analyze the inherent interaction and dissolving mechanism. Complete dissolution of the cellulose bunch was observed in EmimAc, while little change took place in EmimCl and BmimCl, and nothing significant happened in water. The deconstruction of the hydrogen bond (H-bond) network in cellulose was found and analyzed quantitatively. The synergistic effect of cations and anions was revealed by analyzing the whole dissolving process. Initially, cations bind to the side face of the cellulose bunch and anions insert into the cellulose strands to form H-bonds with hydroxyl groups. Then cations start to intercalate into cellulose chains due to their strong electrostatic interaction with the entered anions. The H-bonds formed by Cl(-) cannot effectively separate the cellulose chain and that is the reason why EmimCl and BmimCl dissolve cellulose more slowly. These findings deepen people's understanding on how ILs dissolve cellulose and would be helpful for designing new efficient ILs to dissolve cellulose. PMID:26095890

  14. Blending municipal solid waste with corn stover for sugar production using ionic liquid process.

    PubMed

    Sun, Ning; Xu, Feng; Sathitsuksanoh, Noppadon; Thompson, Vicki S; Cafferty, Kara; Li, Chenlin; Tanjore, Deepti; Narani, Akash; Pray, Todd R; Simmons, Blake A; Singh, Seema

    2015-06-01

    Municipal solid waste (MSW) represents an attractive cellulosic resource for sustainable fuel production. However, its heterogeneity is the major barrier to efficient conversion to biofuels. MSW paper mix was generated and blended with corn stover (CS). It has been shown that both of them can be efficiently pretreated in certain ionic liquids (ILs) with high yields of fermentable sugars. After pretreatment in 1-ethyl-3-methylimidazolium acetate ([C2C1Im][OAc]), over 80% glucose has been released with enzymatic saccharification. We have also applied an enzyme-free process by adding mineral acid and water directly into the IL/biomass slurry to induce hydrolysis. With the acidolysis process in 1-ethyl-3-methylimidazolium chloride ([C2C1Im]Cl), up to 80% glucose and 90% xylose are released. There is a correlation between the viscosity profile and hydrolysis efficiency; low viscosity of the hydrolysate generally corresponds to high sugar yields. Overall, the results indicate the feasibility of incorporating MSW as a robust blending agent for biorefineries. PMID:25817030

  15. Blending municipal solid waste with corn stover for sugar production using ionic liquid process

    SciTech Connect

    Sun, Ning; Xu, Feng; Sathitsuksanoh, Noppadon; Thompson, Vicki S.; Cafferty, Kara; Li, Chenlin; Tanjore, Deepti; Narani, Akash; Pray, Todd R.; Simmons, Blake A.; Singh, Seema

    2015-06-01

    Municipal solid waste (MSW) represents an attractive cellulosic resource for sustainable fuel production because of its abundance and its low or perhaps negative cost. However, the significant heterogeneity and toxic contaminants are barriers to efficient conversion to ethanol and other products. In this study, we generated MSW paper mix, blended with corn stover (CS), and have shown that both MSW paper mix alone and MSW/CS blends can be efficiently pretreated in certain ionic liquids (ILs) with high yields of fermentable sugars. After pretreatment in 1-ethyl-3-methylimidazolium acetate ([C2C1Im][OAc]), over 80% glucose has been released with enzymatic saccharification. We have also applied an enzyme free process by adding mineral acid and water directly into the IL/biomass slurry to induce hydrolysis. With the acidolysis process in the IL 1-ethyl-3-methylimidazolium chloride ([C2C1Im]Cl), up to 80% glucose and 90% xylose are released for MSW. The results indicate the feasibility of incorporating MSW as a robust blending agent for biorefineries.

  16. Analysis of aromatic acids by nonaqueous capillary electrophoresis with ionic-liquid electrolytes.

    PubMed

    Lu, Yuanqi; Wang, Dunqing; Kong, Chunyan; Zhong, Hao; Breadmore, Michael C

    2014-12-01

    The separation of six kinds of aromatic acids by CZE with 1-ethyl-3-methylimidazolium chloride (EMIMCl) and 1-ethyl-3-methylimidazolium hydrogen sulfate (EMIMHSO4 ), two kinds of ionic liquids (ILs) as background electrolytes, and acetonitrile as solvent were investigated. The six kinds of aromatic acids can be separated under positive voltage with low IL concentration with either of the two ILs and separation with EMIMHSO4 is better in consideration of peak shapes and separation efficiency. But the migration order is different when the IL is different. Under negative voltage with high IL concentration, the six analytes can be separated with EMIMCl as background electrolytes and the migration order of the analytes is opposite to those with low concentration of EMIMCl as background electrolyte. The separations are based on the combination effects of heteroconjugation between the anions and cations in the ILs and the analytes, of which the heteroconjugation between the anions in the ILs and the analytes plays a dominant role. The heteroconjugation between the anions of the ILs and analytes is proton sensitive and only a very small amount of proticsolvents added into the electrolyte solution can harm the separation. When EMIMCl concentration is high, the heteroconjugation between the IL anions and the proton in the analytes make the effective mobility of the analytes much higher than the EOF and their migration direction reversed. Finally, the six aromatic acids in water samples were analyzed by nonaqueous CE with low concentration of EMIMHSO4 as background electrolytes with satisfactory results. PMID:25141838

  17. Correlation between Soft X-ray Absorption and Emission Spectra of the Nitrogen Atoms within Imidazolium-Based Ionic Liquids.

    PubMed

    Horikawa, Yuka; Tokushima, Takashi; Takahashi, Osamu; Hoke, Hiroshi; Takamuku, Toshiyuki

    2016-08-01

    Soft X-ray absorption spectroscopy (XAS) has been performed on the N K-edge of two imidazolium-based ionic liquids (ILs), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([C2mim][TFSA]) and 1-ethyl-3-methylimidazolium bromide ([C2mim][Br]), to clarify the electronic structures of the ILs. Soft X-ray emission spectroscopy (XES) has also been applied to the ILs by excitation at various X-ray energies according to the XAS spectra. It was possible to fully associate the XAS peaks with the XES peaks. Additionally, both XAS and XES spectra of the ILs were well reproduced by the theoretical spectra for a single-molecule model on [C2mim](+) and [TFSA](-) using density functional theory. The assignments for the XAS and XES peaks of the ILs were accomplished from both experimental and theoretical approaches. The theoretical XAS and XES spectra of [C2mim](+) and [TFSA](-) did not significantly depend on the conformations of the ions. The reproducibility of the theoretical spectra for the single-molecule model suggested that the interactions between the cations and anions are very weak in the ILs, thus scarcely influencing the electronic structures of the nitrogen atoms. PMID:27388151

  18. In situ SEM observation of the Si negative electrode reaction in an ionic-liquid-based lithium-ion secondary battery.

    PubMed

    Tsuda, Tetsuya; Kanetsuku, Tsukasa; Sano, Teruki; Oshima, Yoshifumi; Ui, Koichi; Yamagata, Masaki; Ishikawa, Masashi; Kuwabata, Susumu

    2015-06-01

    By exploiting characteristics such as negligible vapour pressure and ion-conductive nature of an ionic liquid (IL), we established an in situ scanning electron microscope (SEM) method to observe the electrode reaction in the IL-based Li-ion secondary battery (LIB). When 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)amide ([C2mim][FSA]) with lithium bis(trifluoromethanesulfonyl)amide (Li[TFSA]) was used as the electrolyte, the Si negative electrode exhibited a clear morphology change during the charge process, without any solid electrolyte interphase (SEI) layer formation, while in the discharge process, the appearance was slightly changed, suggesting that a morphology change is irreversible in the charge-discharge process. On the other hand, the use of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([C2mim][TFSA]) with Li[TFSA] did not induce a change in the Si negative electrode. It is interesting to note this distinct contrast, which could be attributed to SEI layer formation from the electrochemical breakdown of [C2mim](+) at the Si negative electrode|separator interface in the [C2mim][TFSA]-based LIB. This in situ SEM observation technique could reveal the effect of the IL species electron-microscopically on the Si negative electrode reaction. PMID:25688094

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

    PubMed

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

    2016-07-01

    The gene of Thermotoga maritima GH10 xylanase (TmXYN10B) was synthesised to study the extreme limits of this hyperthermostable enzyme at high temperatures in the presence of biomass-dissolving hydrophilic ionic liquids (ILs). TmXYN10B expressed from Pichia pastoris showed maximal activity at 100 °C and retained 92 % of maximal activity at 105 °C in a 30-min assay. Although the temperature optimum of activity was lowered by 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc), TmXYN10B retained partial activity in 15-35 % hydrophilic ILs, even at 75-90 °C. TmXYN10B retained over 80 % of its activity at 90 °C in 15 % [EMIM]OAc and 15-25 % 1-ethyl-3-methylimidazolium dimethylphosphate ([EMIM]DMP) during 22-h reactions. [EMIM]OAc may rigidify the enzyme and lower V max. However, only minor changes in kinetic parameter K m showed that competitive inhibition by [EMIM]OAc of TmXYN10B is minimal. In conclusion, when extended enzymatic reactions under extreme conditions are required, TmXYN10B shows extraordinary potential. PMID:27240671

  20. Dissolution enthalpies of cellulose in ionic liquids.

    PubMed

    Parviainen, Helena; Parviainen, Arno; Virtanen, Tommi; Kilpeläinen, Ilkka; Ahvenainen, Patrik; Serimaa, Ritva; Grönqvist, Stina; Maloney, Thaddeus; Maunu, Sirkka Liisa

    2014-11-26

    In this work, interactions between cellulose and ionic liquids were studied calorimetrically and by optical microscopy. Two novel ionic liquids (1,5-Diazabicyclo[4.3.0]non-5-enium propionate and N-methyl-1,5-diazabicyclo[4.3.0]non-5-enium dimethyl phosphate) and 1-ethyl-3-methylimidazolium acetate-water mixtures were used as solvents. Optical microscopy served in finding the extent of dissolution and identifying the dissolution pattern of the cellulose sample. Calorimetric studies identified a peak relating to dissolution of cellulose in solvent. The transition did, however, not indicate complete dissolution, but rather dissolution inside fibre or fibrils. This method was used to study differences between four cellulose samples with different pretreatment or origins. PMID:25256460

  1. Pretreatment of rice hulls by ionic liquid dissolution.

    PubMed

    Lynam, Joan G; Reza, M Toufiq; Vasquez, Victor R; Coronella, Charles J

    2012-06-01

    As a highly available waste product, rice hulls could be a starting block in replacing liquid fossil fuels. However, their silica covering can make further use difficult. This preliminary study investigates effects of dissolving rice hulls in the ionic liquids 1-ethyl-3-methylimidazolium acetate (EMIM Ac), 1-hexyl-3-methylimidazolium chloride, (HMIM Cl), and 1-allyl-3-methylimidazolium chloride (AMIM Cl), and what lignocellulosic components can be precipitated from the used ionic liquid with water and ethanol. EMIM Ac dissolution at 110 °C for 8 h was found to completely remove lignin from rice hulls, while ethanol was capable of precipitating lignin out of the used EMIM Ac. With 8h dissolution at 110 °C using HMIM Cl, approximately 20% of the cellulose in the rice hull sample can be precipitated out using water as co-solvent, while more than 60% of the hemicellulose can be precipitated with ethanol. PMID:22446050

  2. The effect of C2 substitution on melting point and liquid phase dynamics of imidazolium based-ionic liquids: insights from molecular dynamics simulations

    SciTech Connect

    Zhang, Y; Maginn, EJ

    2012-01-01

    Using molecular dynamics simulations, the melting points and liquid phase dynamic properties were studied for four alkyl-imidazolium-based ionic liquids, 1-n-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]), 1-n-butyl-2,3-dimethylimidazolium hexafluorophosphate ([BMMIM][PF6]), 1-ethyl-3-methylimidazolium hexafluorophosphate ([EMIM][PF6]), and 1-ethyl-2,3-dimethylimidazolium hexafluorophosphate ([EMMIM][PF6]), respectively. Experimentally it has been observed that the substitution of a methyl group for a hydrogen at the C2 position of the cation ring leads to an increase in both the melting point and liquid phase viscosity, contrary to arguments that had been made regarding associations between the ions. The melting points of the four ionic liquids were accurately predicted using simulations, as were the trends in viscosity. The simulation results show that the origin of the effect is mainly entropic, although enthalpy also plays an important role.

  3. Ordered ionic liquid structure observed at terraced graphite interfaces.

    PubMed

    He, Xing; Wu, Chengyi; Rajagopal, Karjini; Punpongjareorn, Napat; Yang, Ding-Shyue

    2016-02-01

    Reflection high-energy electron diffraction is presented as a contactless, surface-specific method to probe the ion organization and layering at the ionic liquid-solid interfaces. Three regimes can be identified for the structure of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][Tf2N]) on highly oriented pyrolytic graphite, which is strongly dependent on the distances of ions from the surface. Direct observations showed that the ultrathin ionic liquid (IL) assembly can exhibit bulk-like phase-transition behaviours as a result of the structural matching between the IL and graphite layers and the confinement template effect due to the surface topography of graphite. The present study illustrates the opportunities for conducting further studies of the structures and ultrafast dynamics of IL-solid interfaces. PMID:26775813

  4. Reactions of Lignin Model Compounds in Ionic Liquids

    SciTech Connect

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

    2009-09-15

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

  5. Physically and chemically stable ionic liquid-infused textured surfaces showing excellent dynamic omniphobicity

    SciTech Connect

    Miranda, Daniel F.; Urata, Chihiro; Masheder, Benjamin; Dunderdale, Gary J.; Hozumi, Atsushi; Yagihashi, Makoto

    2014-05-01

    A fluorinated and hydrophobic ionic liquid (IL), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide, effectively served as an advantageous lubricating liquid for the preparation of physically and chemically stable omniphobic surfaces based on slippery liquid-infused porous surfaces. Here, we used particulate microstructures as supports, prepared by the chemical vapor deposition of 1,3,5,7-tetramethylcyclotetrasiloxane and subsequent surface modification with (3-aminopropyl)triethoxysilane. Confirmed by SEM and contact angle measurements, the resulting IL-infused microtextured surfaces are smooth and not only water but also various low surface tension liquids can easily slide off at low substrate tilt angles of <5°, even after exposure to high temperature, vacuum, and UV irradiation.

  6. Complex Structural and Dynamical Interplay of Cyano-Based Ionic Liquids.

    PubMed

    Weber, Henry; Kirchner, Barbara

    2016-03-10

    We carried out ab initio molecular dynamics simulations for the three cyano-based ionic liquids, 1-ethyl-3-methylimidazolium tetracyanoborate ([C2C1Im][B(CN)4]), 1-ethyl-3-methyl-imidazolium dicyanamide ([C2C1Im][N(CN)2]), and 1-ethyl-3-methylimidazolium thiocyanate ([C2C1Im][SCN]). We found that the [SCN]-based ionic liquid is much more prone to π-π stacking interactions as opposed to the other two ionic liquids, contrary to the fact that all liquids bear the same cation. Hydrogen bonding is strong in the dicyanamide- and the thiocyanate-based ionic liquids and it is almost absent in the tetracyanoborate liquid. The anion prefers to stay on-top of the imidazolium ring with the highest priority for the [N(CN)2](-) anion followed by the [B(CN)4](-) anion. We find that experimental viscosity trends cannot be correlated to the hydrogen bond dynamics which is fastest for [B(CN)4](-) followed by [SCN](-) and [N(CN)2](-). For the dynamics of the cation on-top of itself, we find the order of [B(CN)4](-) followed by [N(CN)2](-) and finally by [SCN](-). Interestingly, this trend correlates well with the viscosity, suggesting a relation between the cation-cation dynamics and the viscosity at least for these cyano-based ionic liquids. These findings, especially the apparent correlation between cation-cation dynamics and the viscosity, might be useful for the suggestion of better ionic liquids in electrolyte applications. PMID:26882454

  7. A novel ionic liquid-tolerant Fusarium oxysporum BN secreting ionic liquid-stable cellulase: consolidated bioprocessing of pretreated lignocellulose containing residual ionic liquid.

    PubMed

    Xu, Jiaxing; Wang, Xinfeng; Hu, Lei; Xia, Jun; Wu, Zhen; Xu, Ning; Dai, Benlin; Wu, Bin

    2015-04-01

    In this study, microbial communities from chemicals polluted microhabitats were cultured with the addition of imidazolium-based ionic liquid (IL) to enrich for IL-tolerant microbes. A strain of Fusarium oxysporum BN producing cellulase from these enrichments was capable of growing in 10% (w/v) 1-ethyl-3-methylimidazolium phosphinate, much higher than the normal IL concentrations in the lignocellulose regenerated from ILs. Cellulase secreted by the strain showed high resistance to ILs based on phosphate and sulfate radicals, evidencing of a high conformational stability in relevant media. Gratifyingly, F. oxysporum BN can directly convert IL-pretreated rice straw to bioethanol via consolidated bioprocessing (I-CBP). At optimum fermentation condition, a maximum ethanol yield of 0.125 g ethanol g(-1) of rice straw was finally obtained, corresponding to 64.2% of the theoretical yield. PMID:25625459

  8. High-performance supercapacitors based on poly(ionic liquid)-modified graphene electrodes.

    PubMed

    Kim, Tae Young; Lee, Hyun Wook; Stoller, Meryl; Dreyer, Daniel R; Bielawski, Christopher W; Ruoff, Rodney S; Suh, Kwang S

    2011-01-25

    We report a high-performance supercapacitor incorporating a poly(ionic liquid)-modified reduced graphene oxide (PIL:RG-O) electrode and an ionic liquid (IL) electrolyte (specifically, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide or EMIM-NTf(2)). PIL:RG-O provides enhanced compatibility with the IL electrolyte, thereby increasing the effective electrode surface area accessible to electrolyte ions. The supercapacitor assembled with PIL:RG-O electrode and EMIM-NTf(2) electrolyte showed a stable electrochemical response up to 3.5 V operating voltage and was capable of yielding a maximum energy density of 6.5 W·h/kg with a power density of 2.4 kW/kg. These results demonstrate the potential of the PIL:RG-O material as an electrode in high-performance supercapacitors. PMID:21142183

  9. Simultaneous bench scale production of dissolving grade pulp and valuable hemicelluloses from softwood kraft pulp by ionic liquid extraction.

    PubMed

    Laine, Christiane; Asikainen, Sari; Talja, Riku; Stépán, Agnes; Sixta, Herbert; Harlin, Ali

    2016-01-20

    Ionic liquid extraction of wood pulp has been highlighted as a highly potential new process for dissolving pulp production. Coproduction with a polymeric hemicellulose fraction was demonstrated in bench scale from softwood kraft pulp using extraction with the ionic liquid 1-ethyl-3-methylimidazolium acetate (EMIM OAc) and water. In total, the recovered pulp and hemicellulose fraction together yielded 95.5 wt.% of the pulp input. The extracted pulp had a remarkably high purity with an R18-value of 97.8%. The hemicellulose fraction consisted of galactoglucomannan, arabinoxylan and some cellulose and was precipitated from the ionic liquid-water mixture. After hydroxypropylation of the hemicellulose fraction, films were prepared and barrier and strength properties were compared to films from other polysaccharides. Reduced oxygen and water vapor permeation and good strength properties were demonstrated when compared to corresponding films from hydroxypropylated xylan from cold caustic extraction. The films have potential for applications in food packaging and edible films. PMID:26572370

  10. Lubrication of starch in ionic liquid-water mixtures: Soluble carbohydrate polymers form a boundary film on hydrophobic surfaces.

    PubMed

    Yakubov, Gleb E; Zhong, Lei; Li, Ming; Boehm, Michael W; Xie, Fengwei; Beattie, David A; Halley, Peter J; Stokes, Jason R

    2015-11-20

    Soluble starch polymers are shown to enhance the lubrication of ionic liquid-water solvent mixtures in low-pressure tribological contacts between hydrophobic substrates. A fraction of starch polymers become highly soluble in 1-ethyl-3-methylimidazolium acetate (EMIMAc)-water solvents with ionic liquid fraction ≥60wt%. In 65wt% EMIMAc, a small amount of soluble starch (0.33wt%) reduces the boundary friction coefficient by up to a third in comparison to that of the solvent. This low-friction is associated with a nanometre thick film (ca. 2nm) formed from the amylose fraction of the starch. In addition, under conditions where there is a mixture of insoluble starch particles and solubilised starch polymers, it is found that the presence of dissolved amylose enhances the lubrication of starch suspensions between roughened substrates. These findings open up the possibility of utilising starch biopolymers, as well as other hydrocolloids, for enhancing the performance of ionic liquid lubricants. PMID:26344308

  11. Elucidation of the effect of ionic liquid pretreatment on rice husk via structural analyses

    PubMed Central

    2012-01-01

    Background In the present study, three ionic liquids, namely 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc), and 1-ethyl-3-methylimidazolium diethyl phosphate ([EMIM]DEP), were used to partially dissolve rice husk, after which the cellulose were regenerated by the addition of water. The aim of the investigation is to examine the implications of the ionic liquid pretreatments on rice husk composition and structure. Results From the attenuated total reflectance Fourier transform-infrared (ATR FT-IR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) results, the regenerated cellulose were more amorphous, less crystalline, and possessed higher structural disruption compared with untreated rice husk. The major component of regenerated cellulose from [BMIM]Cl and [EMIM]DEP pretreatments was cellulose-rich material, while cellulose regenerated from [EMIM]OAc was a matrix of cellulose and lignin. Cellulose regenerated from ionic pretreatments could be saccharified via enzymatic hydrolysis, and resulted in relatively high reducing sugars yields, whereas enzymatic hydrolysis of untreated rice husk did not yield reducing sugars. Rice husk residues generated from the ionic liquid pretreatments had similar chemical composition and amorphousity to that of untreated rice husk, but with varying extent of surface disruption and swelling. Conclusions The structural architecture of the regenerated cellulose and rice husk residues showed that they could be used for subsequent fermentation or derivation of cellulosic compounds. Therefore, ionic liquid pretreatment is an alternative in the pretreatment of lignocellulosic biomass in addition to the conventional chemical pretreatments. PMID:22958710

  12. Physico-Chemical Properties and Phase Behavior of the Ionic Liquid-β-Cyclodextrin Complexes

    PubMed Central

    Rogalski, Marek; Modaressi, Ali; Magri, Pierre; Mutelet, Fabrice; Grydziuszko, Aleksandra; Wlazło, Michał; Domańska, Urszula

    2013-01-01

    The solubility of β-cyclodextrin (β-CD) in ionic liquids (ILs) and the activity coefficients at infinite dilution ( γ13∞) of more than 20 solutes (alkanes, aromatic hydrocarbons, alcohols) were measured in four chosen ionic liquids, their mixtures with β-CD, and in the β-CD at high temperatures from 338 to 398 K using the inverse gas chromatography. The intermolecular interactions, inclusion complexes and the possible increasing of the solubility of β-CD in water using the IL are presented. The solubility of β-CD in ten chosen hydrophobic ILs at the temperature T = 423 K was detected. The solid-liquid phase diagrams (SLE) of {IL (1) + β-CD (2)} binary systems at the high mole fraction of the IL were measured for three systems (1-ethyl-3-methylimidazolium chloride, [EMIM][Cl], 1-ethyl-3-methylimidazolium bromide, [EMIM][Br]; and for 1-butyl-3-methylimidazolium chloride, [BMIM][Cl]). The eutectic points were determined at the high IL concentration for all binary systems. The intermolecular interaction and the possibility of inclusion complexes of the IL and/or solvents with β-CD were discussed. The infrared spectroscopy, IR was used for the description of the intermolecular interactions in the (β-CD + IL) systems. It was shown via the activity coefficients at infinite dilution results that the inclusion complexes are dependent on the temperature. The addition of β-CD to the IL does not improve the selectivity of the separation of the aliphatics from aromatics. PMID:23945559

  13. Observation of electrodeposited lithium by optical microscope in room temperature ionic liquid-based electrolyte

    NASA Astrophysics Data System (ADS)

    Sano, H.; Sakaebe, H.; Matsumoto, H.

    Room temperature ionic liquids (RTILs) were applied to a lithium (Li) metal battery system, and the behavior of Li electrodeposition on nickel electrodes in RTILs was investigated using in situ optical microscopy with/without an organic additive, vinylene carbonate (VC), in the RTILs. Two RTILs, PP13[TFSA] (N-methyl- N-propylpiperidinium bis(trifluoromethanesulfonyl)amide) and EMI[FSA] (1-ethyl-3-methylimidazolium bis(fluorosulfonyl)amide), were chosen as the base electrolytes. Dendritic particles were obtained in the case of EMI[FSA] with and without VC, and PP13[TFSA] without VC, while non-dendritic fine particles were obtained in the case of PP13[TFSA] with VC.

  14. Improved dye-sensitized solar cells by composite ionic liquid electrolyte incorporating layered titanium phosphate

    SciTech Connect

    Cheng, Ping; Lan, Tian; Wang, Wanjun; Wu, Haixia; Yang, Haijun; Guo, Shouwu

    2010-05-15

    We reported a composite electrolyte prepared by incorporating layered {alpha}-titanium phosphate ({alpha}-TiP) into a binary ionic liquid of 1-propyl-3-methylimidazolium iodide (PMII) and 1-ethyl-3-methylimidazolium tetrafluoroborate (EmimBF{sub 4}) (volume ratio, 13:7) electrolyte. The addition of {alpha}-TiP markedly improved the photovoltaic properties of dye-sensitized solar cells (DSSCs) compared to that without {alpha}-TiP. The enhancement was explained by improved diffusion of tri-iodide (I{sub 3}{sup -}) ions, suppressed electron recombination with I{sub 3}{sup -} in the electrolyte and increased lifetime of electrons in mesoscopic TiO{sub 2} film. (author)

  15. Cellulose gels produced in room temperature ionic liquids by ionizing radiation

    NASA Astrophysics Data System (ADS)

    Kimura, Atsushi; Nagasawa, Naotsugu; Taguchi, Mitsumasa

    2014-10-01

    Cellulose-based gels were produced in room temperature ionic liquids (RTILs) by ionizing radiation. Cellulose was dissolved at the initial concentration of 20 wt% in 1-ethyl-3-methylimidazolium (EMI)-acetate or N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium (DEMA)-formate with a water content of 18 wt%, and irradiated with γ-rays under aerated condition to produce new cellulose gels. The gel fractions of the cellulose gels obtained in EMI-acetate and DEMA-formate at a dose of 10 kGy were 13% and 19%, respectively. The formation of gel fractions was found to depend on the initial concentration of cellulose, water content, and irradiation temperature. The obtained gel readily absorbed water, methanol, ethanol, dichloromethane, N,N-dimethylacetamide, and RTILs.

  16. Multi-layer stretchable pressure sensors using ionic liquids and carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Vatani, Morteza; Vatani, Mohamad; Choi, J. W.

    2016-02-01

    A stretchable and pressure sensitive polymer capable of detecting strains was developed through the incorporation of 1-ethyl-3-methylimidazolium tetrafluoroborate as an ionic liquid (IL) into a stretchable photopolymer. The developed IL/polymer composite showed both a field effect characteristic and piezoresistivity by embedding the composite between two layers of carbon nanotube (CNT)-based stretchable electrodes. A multi-layer pressure sensitive taxel was formed using a hybrid manufacturing process, where two electrode layers were fabricated by screen printing and the IL/polymer composite was formed by casting using a mold. A composite material for the electrodes was developed through the dispersion of CNTs into a highly stretchable photo/thermal crosslinkable prepolymer. The fabricated sensor was evaluated with different forces ranging from 0 to 140 g. The experiment results showed that the developed stretchable sensor had good repeatability and reliability in detecting applied pressures.

  17. Direct dissolution of wet and saliferous marine microalgae by polar ionic liquids without heating.

    PubMed

    Fujita, Kyoko; Kobayashi, Daigo; Nakamura, Nobuhumi; Ohno, Hiroyuki

    2013-03-01

    We successfully dissolved wet and saliferous microalgae (WSM) in polar ionic liquids (ILs) under mild conditions. The Kamlet-Taft parameters, especially β for the ILs, were good predictors of the ability to dissolve WSM. 1-Ethyl-3-methylimidazolium methylphosphate ([C2mim][MeO(H)PO(2)]) was the IL that best dissolved WSM without heating. WSM (containing 95 wt% water) was mixed with [C2mim][MeO(H)PO(2)]; the WSM had dissolved completely within 30 min at room temperature with gentle stirring. The IL maintained its chemical structure after removal of the microalgae component, suggesting recyclable use. The concentration of contaminant mineral salts in the [C2mim][MeO(H)PO(2)] did not increase with increasing recycle number. The recycled [C2mim][MeO(H)PO(2)] maintained its ability to dissolve WSM regardless of the number of recycling studied here. PMID:23410933

  18. Hydrophilic Ionic Liquids as Ingredients of Gel-Based Dermal Formulations.

    PubMed

    Dobler, Dorota; Schmidts, Thomas; Zinecker, Christina; Schlupp, Peggy; Schäfer, Jens; Runkel, Frank

    2016-08-01

    Ionic liquids (ILs) have several properties that offer many advantages in dermal drug delivery systems. Depending on the chemical structure, ILs can be used for protection against microorganisms, to enhance skin penetration, and as a solvent. In the present work, SEPINEO™ P 600 formulations and hydroxyethylcellulose gels containing the hydrophilic ILs hexylpyridinium chloride, choline dihydrogen phosphate, and 1-ethyl-3-methylimidazolium ethyl sulfate were prepared, and the influence of the ILs on the formulation properties was evaluated. ILs were successfully incorporated into the emulsion structure, resulting in stable formulations. The antimicrobial activity of the ILs was estimated. The minimal inhibitory concentration values for hexylpyridinium chloride are about 2.5 mg/mL. The other two ILs have no antimicrobial activity. Skin penetration enhancement of caffeine, a hydrophilic model substance, was observed in the presence of hexylpyridinium chloride. PMID:27435197

  19. In situ crystallization of ionic liquid [Emim][PF6] from methanol solution under high pressure.

    PubMed

    Li, Haining; Su, Lei; Zhu, Xiang; Cheng, Xuerui; Yang, Kun; Yang, Guoqiang

    2014-07-24

    The solubility of 1-ethyl-3-methylimidazolium hexafluorophosphate ([Emim][PF6]) in methanol under high pressure is newly measured quantitatively according to the correlation between the ratios of Raman intensity and the concentrations. In situ crystallization and cation conformation of [Emim][PF6] from methanol solution under high pressure have been investigated by using Raman spectroscopy in detail. Remarkably, crystal polymorphism was observed and two crystalline phases (phases I and II) coexisted under high pressure up to ∼ 1.4 GPa. However, only phase II was obtained by recrystallization at ∼ 2 GPa. Our findings may facilitate the development of an effective way for crystallization and purification of ionic liquids under high pressure. PMID:24968114

  20. Ionic-liquid-induced ferroelectric polarization in poly(vinylidene fluoride) thin films

    NASA Astrophysics Data System (ADS)

    Wang, Feipeng; Lack, Alexander; Xie, Zailai; Frübing, Peter; Taubert, Andreas; Gerhard, Reimund

    2012-02-01

    Thin films of ferroelectric β-phase poly(vinylidene fluoride) (PVDF) were spin-coated from a solution that contained small amounts of the ionic liquid (IL) 1-ethyl-3-methylimidazolium nitrate. A remanent polarization of 60 mC/m2 and a quasi-static pyroelectric coefficient of 19 μC/m2K at 30 °C were observed in the films. It is suggested that the IL promotes the formation of the β phase through dipolar interactions between PVDF chain-molecules and the IL. The dipolar interactions are identified as Coulomb attraction between hydrogen atoms in PVDF chains and anions in IL. The strong crystallinity increase is probably caused by the same dipolar interaction as well.

  1. Impact of Mixed Feedstocks and Feedstock Densification on Ionic Liquid Pretreatment Efficiency

    SciTech Connect

    Jian Shi; Vicki S. Thompson; Neal A. Yancey; Vitalie Stavila; Blake A. Simmons; Seema Singh

    2013-01-01

    Background: Lignocellulosic biorefineries must be able to efficiently process the regional feedstocks that are available at cost-competitive prices year round. These feedstocks typically have low energy densities and vary significantly in composition. One potential solution to these issues is blending and/or densifying the feedstocks in order to create a uniform feedstock. Results/discussion: We have mixed four feedstocks - switchgrass, lodgepole pine, corn stover, and eucalyptus - in flour and pellet form and processed them using the ionic liquid 1-ethyl-3-methylimidazolium acetate. Sugar yields from both the mixed flour and pelletized feedstocks reach 90% within 24 hours of saccharification. Conclusions: Mixed feedstocks, in either flour or pellet form, are efficiently processed using this pretreatment process, and demonstrate that this approach has significant potential.

  2. Sputter deposition onto ionic liquids: Simple and clean synthesis of highly dispersed ultrafine metal nanoparticles

    SciTech Connect

    Torimoto, Tsukasa; Okazaki, Ken-ichi; Kiyama, Tomonori; Hirahara, Kaori; Tanaka, Nobuo; Kuwabata, Susumu

    2006-12-11

    Sputter deposition of gold (Au) onto ionic liquids (ILs) resulted in the formation of highly dispersed Au nanoparticles without additional chemical species, such as reducing and/or stabilizing agents. The Au nanoparticles in 1-ethyl-3-methylimidazolium tetrafluoroborate had an average diameter (d{sub av}) of 5.5 nm with a standard deviation ({sigma}) of 0.86 nm, while sputter deposition onto N,N,N-trimethyl-N-propylammonium bis(trifluoromethanesulfonyl)imide resulted in the formation of much smaller Au nanoparticles with d{sub av} of 1.9 nm and {sigma} of 0.46 nm. Prolongation of sputtering time results in a higher concentration of Au nanoparticles in ILs, but did not cause a remarkable change in their size.

  3. Electrochemical behaviour of iron in a third-generation ionic liquid: cyclic voltammetry and micromachining investigations.

    PubMed

    Moustafa, Essam M; Mann, Olivier; Fürbeth, Wolfram; Schuster, Rolf

    2009-12-01

    The electrochemical behaviour of Fe in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim](+)Ntf2(-)) and mixtures with Cl(-) is studied with the aim of investigating the applicability of ionic liquids (IL) for the electrochemical machining of iron. Whereas in pure IL iron could not be significantly dissolved, the addition of Cl(-) enables the active dissolution with anodic current densities up to several mA cm(-2). Although several anodic peaks appear in the cyclic voltammograms (CV), the distinct assignment of those electrochemical processes remain difficult. In particular no proof for the formation of FeCl(x) (2-x) complexes during Fe dissolution are deduced from the CV, although such complexes are shown to be stable in the employed electrolyte. In addition, we present electrochemical drilling experiments with short potential pulses, which demonstrate that electrochemical machining of Fe is, in principle, possible in IL based electrolytes, even though hampered by slow machining speed. PMID:19760696

  4. Enantioselective toxicities of chiral ionic liquids 1-alkyl-3-methylimidazolium lactate to aquatic algae.

    PubMed

    Chen, Hui; Zou, Yuqin; Zhang, Lijuan; Wen, Yuezhong; Liu, Weiping

    2014-09-01

    With the wide application of chiral ionic liquids (CILs) as green solvents, their threats to the aquatic environment cannot be ignored. Thus, risk assessment and the prospective design of inherently safe CILs have become more urgent. However, whether enantioselectivity is a feature of the aquatic toxicity of CILs is poorly understood. Herein, we describe the first investigation into the ecotoxicities of CILs toward green algae Scenedesmus obliquus and Euglena gracilis. A series of methylimidazolium lactic ionic liquids, which cation parts with different alkyl chains and anion part is enantiomers of lactate, are used as representative CILs. The results of S. obliquus showed that the EC50 value of L-(+)-1-ethyl-3-methylimidazolium lactate (L-(+)-EMIM L) was more than 5000 μM, while the EC50 value of D-(-)-1-ethyl-3-methylimidazolium lactate (D-(-)-EMIM L) was 2255.21 μM. Such a distinct difference indicates the enantioselective toxicity of CILs to algae. This enantioselectivity initially persisted with increasing carbon chain length, but no longer exhibited when with greater carbon chain lengths, due to changes in the toxicity weightings of the cation parts. Further research showed that the enantioselective effects of CILs resulted from the differences in the production of reactive oxygen species, the damage to cell membrane integrity and cell wall after exposure to CILs. Results from this study showed that monitoring for the racemate CILs will give an inadequate or misleading environmental risk assessment. Thus, we should improve our ability to predict their effects in natural environments. In the meantime, non-selective use of CILs will do harm to aquatic organisms. Therefore, to minimize their potential for environmental impact, the enantioselective toxicities of CILs with short alkyl chains should be taken into consideration. PMID:24880783

  5. Improved in situ saccharification of cellulose pretreated by dimethyl sulfoxide/ionic liquid using cellulase from a newly isolated Paenibacillus sp. LLZ1.

    PubMed

    Hu, Dongxue; Ju, Xin; Li, Liangzhi; Hu, Cuiying; Yan, Lishi; Wu, Tianyun; Fu, Jiaolong; Qin, Ming

    2016-02-01

    A cellulase producing strain was newly isolated from soil samples and identified as Paenibacillus sp. LLZ1. A novel aqueous-dimethyl sulfoxide (DMSO)/1-ethyl-3-methylimidazolium diethyl phosphate ([Emin]DEP)-cellulase system was designed and optimized. In the pretreatment, DMSO was found to be a low-cost substitute of up to 70% ionic liquid to enhance the cellulose dissolution. In the enzymatic saccharification, the optimum pH and temperature of the Paenibacillus sp. LLZ1 cellulase were identified as 6.0 and 40°C, respectively. Under the optimized reaction condition, the conversion of microcrystalline cellulose and bagasse cellulose increased by 39.3% and 37.6%, compared with unpretreated cellulose. Compared to current methods of saccharification, this new approach has several advantages including lower operating temperature, milder pH, and less usage of ionic liquid, indicating a marked progress in environmental friendly hydrolysis of biomass-based materials. PMID:26618784

  6. Steric repulsion as a way to achieve the required stability for the preparation of ionic liquid-based ferrofluids.

    PubMed

    Rodríguez-Arco, Laura; López-López, Modesto T; González-Caballero, Fernando; Durán, Juan D G

    2011-05-01

    With this work we would like to emphasize the necessity of steric repulsion to stabilize novel ionic liquid-based ferrofluids. For this purpose, we prepared a suspension of magnetite nanoparticles coated with a double layer of oleic acid, dispersed in 1-ethyl-3-methylimidazolium ethylsulphate ([EMIM][EtSO(4)]). For comparison, a suspension of bare magnetite nanoparticles in [EMIM][EtSO(4)] was also prepared. The stability of these suspensions was checked by magnetic sedimentation and centrifugation processes. Furthermore, their yield stress was measured as a function of the applied magnetic field, which gave additional information on their stability. The results of these experiments showed that the suspension of bare nanoparticles was rather unstable, whereas the suspension of double layer coated nanoparticles gave rise to a true (stable) ferrofluid. PMID:21345446

  7. The Effect of Microporous Polymeric Support Modification on Surface and Gas Transport Properties of Supported Ionic Liquid Membranes

    PubMed Central

    Akhmetshina, Alsu A.; Davletbaeva, Ilsiya M.; Grebenschikova, Ekaterina S.; Sazanova, Tatyana S.; Petukhov, Anton N.; Atlaskin, Artem A.; Razov, Evgeny N.; Zaripov, Ilnaz I.; Martins, Carla F.; Neves, Luísa A.; Vorotyntsev, Ilya V.

    2015-01-01

    Microporous polymers based on anionic macroinitiator and toluene 2,4-diisocyanate were used as a support for 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([emim][Tf2N]) immobilization. The polymeric support was modified by using silica particles associated in oligomeric media, and the influence of the modifier used on the polymeric structure was studied. The supported ionic liquid membranes (SILMs) were tested for He, N2, NH3, H2S, and CO2 gas separation and ideal selectivities were calculated. The high values of ideal selectivity for ammonia-based systems with permanent gases were observed on polymer matrixes immobilized with [bmim][PF6] and [emim][Tf2N]. The modification of SILMs by nanosize silica particles leads to an increase of NH3 separation relatively to CO2 or H2S. PMID:26729177

  8. Cellulose amorphization by swelling in ionic liquid/water mixtures: a combined macroscopic and second-harmonic microscopy study.

    PubMed

    Glas, Daan; Paesen, Rik; Depuydt, Daphne; Binnemans, Koen; Ameloot, Marcel; De Vos, Dirk E; Ameloot, Rob

    2015-01-01

    Amorphization of cellulose by swelling in ionic liquid (IL)/water mixtures at room temperature is a suitable alternative to the dissolution-precipitation pretreatment known to facilitate enzymatic digestion. When soaking microcrystalline cellulose in the IL 1-ethyl-3-methylimidazolium acetate containing 20 wt % water, the crystallinity of the cellulose sample is strongly reduced. As less than 4 % of the cellulose dissolves in this mixture, this swelling method makes a precipitation step and subsequent energy-intensive IL purification redundant. Second-harmonic generation (SHG) microscopy is used as a structure-sensitive technique for in situ monitoring of the changes in cellulose crystallinity. Combined optical and SHG observations confirm that in the pure IL complete dissolution takes place, while swelling without dissolution in the optimal IL/water mixture yields a solid cellulose with a significantly reduced crystallinity in a single step. PMID:25363520

  9. A molecular dynamics computer simulation study of room-temperature ionic liquids. I. Equilibrium solvation structure and free energetics

    NASA Astrophysics Data System (ADS)

    Shim, Y.; Choi, M. Y.; Kim, Hyung J.

    2005-01-01

    Solvation in 1-ethyl-3-methylmidazolium chloride and in 1-ethyl-3-methylimidazolium hexafluorophosphate near equilibrium is investigated via molecular dynamics computer simulations with diatomic and benzenelike molecules employed as probe solutes. It is found that electrostriction plays an important role in both solvation structure and free energetics. The angular and radial distributions of cations and anions become more structured and their densities near the solute become enhanced as the solute charge separation grows. Due to the enhancement in structural rigidity induced by electrostriction, the force constant associated with solvent configuration fluctuations relevant to charge shift and transfer processes is also found to increase. The effective polarity and reorganization free energies of these ionic liquids are analyzed and compared with those of highly polar acetonitrile. Their screening behavior of electric charges is also investigated.

  10. Neutron Powder Diffraction study of the Magnetic Ionic Liquid Emim[FeCL4] and its deuterated phase

    NASA Astrophysics Data System (ADS)

    García-Saiz, A.; de Pedro, I.; Fernández Barquín, L.; Fernández-Díaz, M. T.; Blanco, J. A.; Rodríguez Fernández, J.

    2015-11-01

    A magnetic ionic liquid comprising 1-ethyl-3 methylimidazolium (Emim) cations and tetraclhoroferrate(III) (FeCl4) anions and its deuterated phase were synthetized and characterized magnetically. In both materials, the low temperature dependence of the magnetic susceptibility presents a maximum (around 4 K) related to an antiferromagnetic ordering, but the ordering temperatures are slightly shifted and the curves display different shapes. In addition, the magnetization of the deuterated phase tends to saturate at higher values than that corresponding to the non-deuterated analogue. A comparison of the neutron diffraction patterns above and below the magnetic transition clearly shows that the crystal and magnetic structures of these materials are different. Therefore, the present findings clearly prove that the magnetic exchange interactions that induce three-dimensional magnetic ordering are modified after the deuteration process.

  11. Fixation of CO2 by electrocatalytic reduction and electropolymerization in ionic liquid-H2O solution.

    PubMed

    Chu, Daobao; Qin, Guoxu; Yuan, Ximei; Xu, Mai; Zheng, Peng; Lu, Jia

    2008-01-01

    The electrocatalytic synthesis of low-density polyethylene (LDPE) from carbon dioxide on a nanostructured (ns)TiO2 film electrode was investigated by controlled potential electrolysis in a solvent mixture of water and the ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMI]BF4) at room temperature under ambient pressure. Under these conditions, the nsTiO2 film is remarkably efficient and selective for the electroreduction of CO2. The current efficiency for the formation of the electrolytic product is about 8-14% at -1.50 V (vs SCE). The electrocatalytic activity of the electrode in the electrochemical reduction of CO2 was investigated by cyclic voltammetry (CV), and the probable electrode reaction mechanism is discussed. PMID:18605207

  12. Highly Safe Ionic Liquid Electrolytes for Sodium-Ion Battery: Wide Electrochemical Window and Good Thermal Stability.

    PubMed

    Wu, Feng; Zhu, Na; Bai, Ying; Liu, Libin; Zhou, Hang; Wu, Chuan

    2016-08-24

    Novel ionic liquid (IL) electrolytes are prepared by mixing 1-ethyl-3-methylimidazolium-bis-tetrafluoroborate (EMIBF4) with different concentrations of sodium salt (NaBF4). The as-prepared IL electrolytes display wide electrochemical windows of ∼4 V (1-5 V), which are consistent with the quantum chemical theoretical calculation. The IL electrolyte with 0.1 M NaBF4 shows excellent ionic conductivity, namely, 9.833 × 10(-3) S cm(-1) at 20 °C. In addition, nonflammability and good thermal stability are exhibited by combustion test and thermogravimetric analysis (TGA), which indicate the high safety of the IL electrolyte. PMID:27454818

  13. Evaluation of thermophysical properties of ionic liquids with polar solvent: a comparable study of two families of ionic liquids with various ions.

    PubMed

    Govinda, Varadhi; Attri, Pankaj; Venkatesu, Punnuru; Venkateswarlu, Ponneri

    2013-10-17

    In this work, we explore and compare the role of the ion effect on the thermophysical properties of two families of ionic liquids (ILs), namely, tetra-alkyl ammonium cation [R4N](+) with hydroxide [OH](-) anion and 1-alkyl-3-methyl imidazolium cation [amim](+) with different anions (chloride, methyl sulfate, and tetrafluoroborate), with polar solvent such as dimethylsulfoxide (DMSO) in the temperature range from 25 to 40 °C and over the whole concentration range of ILs. Two families of ILs, namely, tetramethyl ammonium hydroxide [(CH3)4N][OH] (TMAH), tetraethyl ammonium hydroxide [(C2H5)4N][OH] (TEAH), tetrapropyl ammonium hydroxide [(C3H7)4N][OH] (TPAH), and tetrabutyl ammonium hydroxide [(C4H9)4N][OH] (TBAH) from ammonium-based ILs and 1-ethyl-3-methylimidazolium chloride [Emim][Cl], 1-ethyl-3-methylimidazolium methylsulfate [Emim][MeSO4], 1-butyl-3-methylimidazolium tetrafluoroborate [Bmim][BF4], and 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]) from imidazolium family of ILs, are used in the present study. To address the molecular interactions of ILs with DMSO, densities (ρ), ultrasonic sound velocities (u), and viscosities (η) have been measured over the entire composition range and at four temperatures, 25, 30, 35, and 40 °C, under atmospheric pressure. From these experimental data, the excess molar volume (V(E)), the deviation in isentropic compressibility (Δκs), and the deviation in viscosity (Δη) were calculated and were adequately correlated by using the Redlich-Kister polynomial equation. The measured and predicted data were interpreted on the basis of intermolecular interactions and structural effects between like and unlike molecules upon mixing. The hydrogen-bonding features between ammonium-based ILs and DMSO were analyzed using molecular modeling program by HyperChem 7. PMID:24087984

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

    PubMed

    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

    2014-09-01

    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. PMID:25136131

  15. The impact of ionic liquid fluorinated moieties on their thermophysical properties and aqueous phase behaviour

    PubMed Central

    Neves, Catarina M. S. S.; Kurnia, Kiki A.; Shimizu, Karina; Marrucho, Isabel M.; Rebelo, Luís Paulo N.; Coutinho, João A. P.; Freire, Mara G.; Lopes, José N. Canongia

    2014-01-01

    In this work, we demonstrate that the presence of fluorinated alkyl chains in Ionic Liquids (ILs) is highly relevant in terms of their thermophysical properties and aqueous phase behaviour. We have measured and compared the density and viscosity of pure 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate, [C2C1im][FAP], with that of pure 1-ethyl-3-methylimidazolium hexafluorophosphate, [C2C1im][PF6], at atmospheric pressure and in the (288.15 to 363.15) K temperature range. The results show that the density of [C2C1im][PF6] is lower than that of [C2C1im][FAP], while the viscosity data reveal the opposite trend. The fluid phase behaviour of aqueous solutions of the two ILs was also evaluated under the same conditions and it was found that the mutual solubilities of [C2C1im][FAP] and water are substantially lower than those verified with [C2C1im][PF6]. The experimental data were lastly interpreted at a molecular level using Molecular Dynamics (MD) simulation results revealing that the interactions between the IL ions and the water molecules are mainly achieved via the six fluorine atoms of [PF6]− and the three analogues in [FAP]−. The loss of three interaction centres when replacing [PF6]− by [FAP]−, coupled with the bulkiness and relative inertness of the three perfluoroethyl groups, reduces its mutual solubility with water and also contributes to a lower viscosity displayed by the pure [FAP]-based IL as compared to that of the [PF6]-based compound. PMID:25179181

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

    PubMed Central

    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

    2014-01-01

    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. PMID:25136131

  17. Are ionic liquids pairwise in gas phase? A cluster approach and in situ IR study.

    PubMed

    Dong, Kun; Zhao, Lidong; Wang, Qian; Song, Yuting; Zhang, Suojiang

    2013-04-28

    In this work, we discussed the vaporization and gas species of ionic liquids (ILs) by a cluster approach of quantum statistical thermodynamics proposed by R. Luwig (Phys. Chem. Chem. Phys., 10, 4333), which is a controversial issue up to date. Based on the different sized clusters (2-12 ion-pairs) of the condensed phase, the molar enthalpies of vaporization (ΔvapH, 298.15 K, 1bar) of four representative ILs, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][NTf2]) 1-ethyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide ([Emmim][NTf2]) 1-ethyl-3-methylimidazolium chloride ([Emim]Cl) and ethylammonium nitrate ([EtAm][NO3]), were calculated. The predicted ΔvapH were increased remarkably; even the values of [EtAm][NO3] were larger than 700 kJ mol(-1) when the charged isolated ions were assumed to be gas species. However, the ΔvapH were close to experimental measurements when the gas species assumed to be anion-cation pairwise, indicating that the different conformational ion-pairs can coexist in the gas phase when the IL is evaporated. Particularly for the protic IL, [EtAm][NO3], even the neutral precursor molecules by proton transfer can occur in gas phase. In addition, it's found that the effect of hydrogen bonds on the vaporization cannot be negligible by comparing the ΔvapH of [Emim][NTf2] with [Emmim][NTf2]. The in situ and calculated IR spectra provided the further proof that the ions are pairwise in gas phase. PMID:23493905

  18. Structural change of ionic association in ionic liquid/water mixtures: A high-pressure infrared spectroscopic study

    NASA Astrophysics Data System (ADS)

    Umebayashi, Yasuhiro; Jiang, Jyh-Chiang; Shan, Yu-Lun; Lin, Kuan-Hung; Fujii, Kenta; Seki, Shiro; Ishiguro, Shin-Ichi; Lin, Sheng Hsien; Chang, Hai-Chou

    2009-03-01

    High-pressure infrared measurements were carried out to observe the microscopic structures of two imidazolium-based ionic liquids, i.e., 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide [EMI+(CF3SO2)2N-, EMI+TFSA-] and 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)amide [EMI+(FSO2)2N-, EMI+FSA-]. The results obtained at ambient pressure indicate that the imidazolium C-H may exist in two different forms, i.e., isolated and network structures. As the sample of pure EMI+FSA- was compressed, the network configuration is favored with increasing pressure by debiting the isolated form. For EMI+TFSA-/H2O mixtures, the imidazolium C-H peaks split into four bands at high pressures. The new spectral features at approximately 3117 and 3190 cm-1, being concentration sensitive, can be attributed to the interactions between the imidazolium C-H and water molecules. The alkyl C-H absorption exhibits a new band at approximately 3025 cm-1 under high pressures. This observation suggests the formation of a certain water structure around the alkyl C-H groups. The O-H stretching absorption reveals two types of O-H species, i.e., free O-H and bonded O-H. For EMI+TFSA-/H2O mixtures, the compression leads to a loss of the free O-H band intensities, and pressure somehow stabilizes the bonded O-H configurations. The results also suggest the non-negligible roles of weak hydrogen bonds in the structure of ionic liquids.

  19. Communication: Collective dynamics of room-temperature ionic liquids and their Li ion solutions studied by high-resolution inelastic X-ray scattering

    NASA Astrophysics Data System (ADS)

    Fujii, Kenta; Shibayama, Mitsuhiro; Yamaguchi, Tsuyoshi; Yoshida, Koji; Yamaguchi, Toshio; Seki, Shiro; Uchiyama, Hiroshi; Baron, Alfred Q. R.; Umebayashi, Yasuhiro

    2013-04-01

    High-resolution inelastic X-ray scattering (IXS) measurements were performed for room-temperature ionic liquids (ILs) of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide and bis(fluorosulfonyl)amide, [C2mIm+][TFSA-] and [C2mIm+][FSA-], respectively, at ambient temperature. The observed spectra as a function of Q of 1.4-6 nm-1 can be ascribed to quasi-elastic and inelastic scatterings, so that they are well represented with the fitting by using the Lorentz and the damped harmonic oscillator model functions to yield the dynamic structure factors. It was found in the intermediate scattering function, F(Q, t) that both ILs show the relaxation at t < 10 ps. The IXS measurements were also made on [C2mIm+][TFSA-] and [C2mIm+][FSA-] solutions dissolving Li salt. It is suggested that the adding of Li salt to IL significantly prolongs the relaxation time.

  20. Brønsted acids in ionic liquids: how acidity depends on the liquid structure.

    PubMed

    McCune, Jade A; He, Peizhao; Petkovic, Marina; Coleman, Fergal; Estager, Julien; Holbrey, John D; Seddon, Kenneth R; Swadźba-Kwaśny, Małgorzata

    2014-11-14

    Gutmann Acceptor Number (AN) values have been determined for Brønsted acid-ionic liquid mixtures, over a wide compositional range. Four systems of general formula [C2mim][A]-HA (A(-) = bistriflamide, [NTf2](-); triflate, [OTf](-); mesylate, [OMs](-); or acetate, [OAc](-), [C2mim](+) = 1-ethyl-3-methylimidazolium cation) were studied. A library of Brønsted acidic systems of varying acidity was constructed and the AN parameter was found to be a convenient approach for quantifying their acidity. HOAc, HOMs and HOTf, when dissolved in ionic liquids, were found to associate with the respective anions to form hydrogen-bonded anionic clusters, [A(HA)x](-). In contrast, HNTf2 was solubilised as a discrete, undissociated molecule. AN values were sensitive to the presence of anionic clusters; acidity could be buffered to a particular AN by binding the solubilised acid in the anionic cluster form. Overall, a simple way to manipulate and quantify the Brønsted acidity of acid-ionic liquid mixtures was demonstrated, and measured AN values were related to liquid speciation. PMID:25254612

  1. Determination of solubility parameters of ionic liquids and ionic liquid/solvent mixtures from intrinsic viscosity.

    PubMed

    Weerachanchai, Piyarat; Wong, Yuewen; Lim, Kok Hwa; Tan, Timothy Thatt Yang; Lee, Jong-Min

    2014-11-10

    The total and partial solubility parameters (dispersion, polar and hydrogen-bonding solubility parameters) of ten ionic liquids were determined. Intrinsic viscosity approaches were used that encompassed a one-dimensional method (1D-Method), and two different three-dimensional methods (3D-Method1 and 3D-Method2). The effect of solvent type, the dimethylacetamide (DMA) fraction in the ionic liquid, and dissolution temperature on solubility parameters were also investigated. For all types of effect, both the 1D-Method and 3D-Method2 present the same trend in the total solubility parameter. The partial solubility parameters are influenced by the cation and anion of the ionic liquid. Considering the effect on partial solubility parameters of the solvent type in the ionic liquid, it was observed that in both 3D methods, the dispersion and polar parameters of a 1-ethyl-3-methylimidazolium acetate/solvent (60:40 vol %) mixture tend to increase as the total solubility parameter of the solvent increases. PMID:25145759

  2. Recyclability of an ionic liquid for biomass pretreatment.

    PubMed

    Weerachanchai, Piyarat; Lee, Jong-Min

    2014-10-01

    This study investigated the possibility of reusing an ionic liquid for the pretreatment of biomass. The effects of lignin and water content in a pretreatment solvent on pretreatment products were examined, along with the recyclability of an ionic liquid for pretreatment. It was discovered that the presence of lignin and water within a pretreatment solvent resulted in a far less effective pretreatment process. 1-Ethyl-3-methylimidazolium acetate/ethanolamine (60/40 vol%) presents more promising properties than EMIM-AC, providing a small decrease in sugar conversion and also a small increase of lignin deposition with an increasing lignin amount in the pretreatment solvent. Deteriorations of the ionic liquid were observed from considerably low sugar conversions and lignin extraction after using the 5th and 7th batch, respectively. Furthermore, the changes of ionic liquid properties and lignin accumulation in ionic liquid were determined by analyzing their thermal decomposition behavior (TGA) and chemical functional groups (FTIR and (1)H NMR). PMID:25063976

  3. Microscopic characterization of tension wood cell walls of Japanese beech (Fagus crenata) treated with ionic liquids.

    PubMed

    Kanbayashi, Toru; Miyafuji, Hisashi

    2016-09-01

    Tension wood that is an abnormal part formed in angiosperms has been barely used for wood industry. In this study, to utilize the tension wood effectively by means of liquefaction using ionic liquid, we performed morphological and topochemical determination of the changes in tension wood of Japanese beech (Fagus crenata) during ionic liquid treatment at the cellular level using light microscopy, scanning electron microscopy and confocal Raman microscopy. Ionic liquid treatment induced cell wall swelling in tension wood. Changes in the tissue morphology treated with ionic liquids were different between normal wood and tension wood, moreover the types of ionic liquids. The ionic liquid 1-ethyl-3-methylimidazolium chloride liquefied gelatinous layers rapidly, whereas 1-ethylpyridinium bromide liquefied slowly but delignified selectively. These novel insights into the deconstruction behavior of tension wood cell walls during ionic liquid treatment provide better understanding of the liquefaction mechanism. The obtained knowledge will contribute to development of an effective chemical processing of tension wood using ionic liquids and lead to efficient use of wood resources. PMID:27285953

  4. Direct UV-spectroscopic measurement of selected ionic-liquid vapors

    SciTech Connect

    Dai, Sheng; Luo, Huimin; Wang, Congmin; Li, Haoran

    2010-01-01

    The hallmark of ionic liquids lies in their negligible vapor pressure. This ultralow vapor pressure makes it difficult to conduct the direct spectroscopic measurement of ionic-liquid vapors. In fact, there have been no electronic spectroscopic data currently available for ionic-liquid vapors. This deficiency significantly hampers the fundamental understanding of the unique molecular structures of ionic liquids. Herein, the UV absorption spectra of eight ionic liquids, such as 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([Bmim{sup +}] [Tf{sub 2}N{sup -}]) and 1-ethyl-3-methylimidazolium bis(perfluoroethylsulfonyl)imide ([Emim{sup +}][beti{sup -}]) in the vapor phase in a distillation-like environment, were measured through a high-temperature spectroscopic technique to fill this knowledge gap. Two strong absorption peaks of the [Bmim{sup +}][Tf{sub 2}N{sup -}] vapor lie at 202 and 211 nm, slightly different from those of the neat [Bmim{sup +}][Tf{sub 2}N{sup -}] thin film and its solution in water. Based on the quantitative determination of the vapor absorption spectra as a function of temperature, the vaporization enthalpies of these ionic liquids vapors were measured and found to be in good agreement with the corresponding literature values. This in situ method opens up a new avenue to study the nature of ionic-liquid vapors and to determine the vaporization enthalpies of ionic liquids.

  5. How can a carbene be active in an ionic liquid?

    PubMed

    Thomas, Martin; Brehm, Martin; Hollóczki, Oldamur; Kirchner, Barbara

    2014-02-01

    The solvation of the carbene 1-ethyl-3-methylimidazole-2-ylidene in the ionic liquid 1-ethyl-3-methylimidazolium acetate was investigated by ab initio molecular dynamics simulations in order to reveal the interaction between these two highly important classes of materials: N-heterocyclic carbenes with superb catalytic activity and ionic liquids with advantageous properties as solvents and reaction media. In contrast to previously published data on analogous systems, no hydrogen bond is observed between the hypovalent carbon atom and the most acidic ring hydrogen atoms, as these interaction sites of the imidazolium ring are predominantly occupied by the acetate ions. Keeping the carbene away from the ring hydrogen atoms prevents stabilization of this reactive species, and hence any retarding effect on subsequent reactions, which explains the observed high reactivity of the carbene in acetate-based ionic liquids. Instead, the carbene exhibits a weaker interaction with the methyl group of the imidazolium cation by forming a hitherto unprecedented kind of C⋅⋅⋅H-C hydrogen bond. This unexpected finding not only indicates a novel kind of hydrogen bond for carbenes, but also shows that such interaction sites of the imidazolium cation are not limited to the ring hydrogen atoms. Thus, the results give the solute-solvent interactions within ionic liquids a new perspective, and provide a further, albeit weak, site of interaction to tune in order to achieve the desired environment for any dissolved active ingredient. PMID:24375892

  6. A theoretical and experimental chemist's joint view on hydrogen bonding in ionic liquids and their binary mixtures.

    PubMed

    Stark, Annegret; Brehm, Martin; Brüssel, Marc; Lehmann, Sebastian B C; Pensado, Alfonso S; Schöppke, Matthias; Kirchner, Barbara

    2014-01-01

    A combined experimental and theoretical approach including quantum chemistry tools and computational simulation techniques can provide a holistic description of the nature of the interactions present in ionic liquid media. The nature of hydrogen bonding in ionic liquids is an especially intriguing aspect, and it is affected by all types of interactions occurring in this media. Overall, these interactions represent a delicate balance of forces that influence the structure and dynamics, and hence the properties of ionic liquids. An understanding of the fundamental principles can be achieved only by a combination of computations and experimental work. In this contribution we show recent results shedding light on the nature of hydrogen bonding, for certain cases the formation of a three-dimensional network of hydrogen bonding, and its dynamics by comparing 1-ethyl-3-methylimidazolium based acetate, chloride and thiocyanate ionic liquids.A particularly interesting case to study hydrogen bonding and other interactions is the investigation of binary mixtures of ionic liquids of the type [cation1][anion1]/[cation1][anion2]. In these mixtures, competing interactions are to be expected. We present both a thorough property meta-analysis of the literature and new data covering a wide range of anions, i.e., mixtures of 1-ethyl-3-methylimidazolium acetate with either trifluoroacetate, tetrafluoroborate, methanesulfonate, or bis(trifluoromethanesulfonyl)imide. In most cases, ideal mixing behavior is found, a surprising result considering the multitude of interactions present. However, ideal mixing behavior allows for the prediction of properties such as density, refractive index, surface tension, and, in most cases, viscosity as function of molar composition. Furthermore, we show that the prediction of properties such as the density of binary ionic liquid mixtures is possible by making use of group contribution methods which were originally developed for less complex non

  7. Studies on the Reaction of Iron(II) with NO in a Noncoordinating Ionic Liquid.

    PubMed

    Begel, Svetlana; Puchta, Ralph; Sutter, Jörg; Heinemann, Frank W; Dahlenburg, Lutz; Eldik, Rudi van

    2015-07-20

    In an earlier study we investigated the reaction of iron(II) chloride with NO in a strongly coordinating ionic liquid 1-ethyl-3-methylimidazolium dicyanamide [emim][dca] and showed that the actual reactive species in solution was [Fe(II)(dca)5Cl](4-). For the present report we investigated in detail how this reaction could proceed in a noncoordinating ionic liquid 1-ethyl-3-methylimidazolium trifluoromethylsulfonate [emim][OTf]. The donor ability of OTf(-) is much lower than that of dca(-), such that the solubility of FeCl2 in [emim][OTf] strongly depended on other donors like water or chloride ions present or added to the ionic liquid. On increasing the chloride concentration in [emim][OTf], the tetrachloridoferrate complex [emim]2[FeCl4] was formed, as verified by X-ray crystallography. This complex undergoes reversible binding of NO, for which the UV-vis spectral characteristics of the green-brown nitrosyl product resembled that found for the corresponding nitrosyl complexes formed in water and [emim][dca] as solvents. A detailed analysis of the spectra revealed that the {Fe-NO}(7) species has Fe(II)-NO(•) character in contrast to Fe(III)-NO(-) as found for the other solvents. The formation constant, however, is much higher than in [emim][dca], lying closer to the value found for water as solvent. Surprisingly, the Mössbauer spectrum found in [emim][OTf] is very unusual and unsimilar to that found in water and [emim][dca] as solvents, pointing at a different electron density distribution between Fe and NO in {Fe-NO}.7 First, the high isomer shift points to the presence of iron(II) species in solution, thus indicating that upon NO binding no oxidation to iron(III) occurs. Second, the negligible quadrupole splitting suggests a high local symmetry around the iron center. The nitrosyl product is suggested to be [Fe(II)Cl3NO](-), which is supported by electron paramagnetic resonance (EPR) and IR measurements. The nature of the Fe(II) complexes formed in [emim

  8. Structure of cyano-anion ionic liquids: X-ray scattering and simulations

    NASA Astrophysics Data System (ADS)

    Dhungana, Kamal B.; Faria, Luiz F. O.; Wu, Boning; Liang, Min; Ribeiro, Mauro C. C.; Margulis, Claudio J.; Castner, Edward W.

    2016-07-01

    Ionic liquids with cyano anions have long been used because of their unique combination of low-melting temperatures, reduced viscosities, and increased conductivities. Recently we have shown that cyano anions in ionic liquids are particularly interesting for their potential use as electron donors to excited state photo-acceptors [B. Wu et al., J. Phys. Chem. B 119, 14790-14799 (2015)]. Here we report on bulk structural and quantum mechanical results for a series of ionic liquids based on the 1-ethyl-3-methylimidazolium cation, paired with the following five cyano anions: SeCN-, SCN-, N(CN) 2 -, C(CN) 3 -, and B(CN) 4 -. By combining molecular dynamics simulations, high-energy X-ray scattering measurements, and periodic boundary condition DFT calculations, we are able to obtain a comprehensive description of the liquid landscape as well as the nature of the HOMO-LUMO states for these ionic liquids in the condensed phase. Features in the structure functions for these ionic liquids are somewhat different than the commonly observed adjacency, charge-charge, and polarity peaks, especially for the bulkiest B(CN) 4 - anion. While the other four cyano-anion ionic liquids present an anionic HOMO, the one for Im2,1 +/B(CN) 4 - is cationic.

  9. MD Study of Stokes Shifts in Ionic Liquids: Temperature Dependence.

    PubMed

    Wu, Eric C; Kim, Hyung J

    2016-05-26

    Effects of temperature on Stokes shifts, solvation structure, and dynamics in ionic liquids EMI(+)Tf2N(-), EMI(+)PF6(-), and BMI(+)PF6(-) (EMI(+) = 1-ethyl-3-methylimidazolium, BMI(+) = 1-butyl-3-methylimidazolium, Tf2N(-) = bis(trifluoromethylsulfonyl)imide, and PF6(-) = hexafluorophosphate) are investigated via molecular dynamics (MD) computer simulations in the temperature range 350 K ≤ T ≤ 500 K. Two different types of solutes are considered: a simple model diatomic solute and realistic coumarin 153, both of which are characterized by more polar S1 and less polar S0 states. In all three ionic liquids studied, the Stokes shift tends to decrease with increasing temperature. For coumarin 153, as T increases, the Franck-Condon energy for steady-state absorption decreases, whereas that for steady-state emission increases. Our findings indicate that the effective polarity of ionic liquids decreases as T increases. Their solvation dynamics are characterized by an ultrafast initial decay in the subpicosecond time scale, followed by slow dissipative relaxation, regardless of temperature. For both solutes, the solvent frequency that quantifies initial ultrafast dynamics shows little temperature dependence. By contrast, the long-time dissipative dynamics become significantly faster with rising T. Variations of solvation structure with temperature and their connection to Stokes shift and solvation dynamics are briefly examined. PMID:27133895

  10. Ring Opened Heterocycles: Promising Ionic Liquids for Gas Separation and Capture

    SciTech Connect

    Mahurin, Shannon Mark; Yeary, Joshua S; Baker, Sheila N; Jiang, Deen; Dai, Sheng; Baker, Gary A

    2012-01-01

    We report on a new class of highly fluid ionic liquids integrating a cation that resembles an opened imidazolium structure with two distinct anions, bis(trifluoromethylsulfonyl)imide, [Tf{sub 2}N], and a nitrile-containing anion, [C(CN)3]. These new ionic liquids show exceptional CO{sub 2} permeability values in liquid membrane gas separations with results that equal or exceed the Robeson upper bound. Moreover, these ionic liquids offer ideal CO{sub 2}/N{sub 2} selectivities competitive with the best results reported to date, exhibiting values that range from 28 to 45. The nitrile containing ionic liquid displayed the highest ideal CO{sub 2}/N{sub 2} selectivity with a value of 45 which primarily results from a reduction in the nitrogen permeability. In addition to permeability results, CO{sub 2} solubilities were also measured for the this new class of ionic liquids with values similar to the popular 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. The CO{sub 2} solubility results were compared to predicted values obtained using both a modified regular solution theory and the quantum chemical Conductor-like Screening Model for Real Solvents (COSMO-RS) method. Agreement between predicted and measured solubility values is also discussed.

  11. Study of tribochemical decomposition of ionic liquids on a nascent steel surface

    NASA Astrophysics Data System (ADS)

    Lu, Renguo; Mori, Shigeyuki; Kobayashi, Kimihiro; Nanao, Hidetaka

    2009-08-01

    Tribological properties and the decomposition process of ionic liquids (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide and 1-dodecyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide) on a nascent surface of bearing steel 52100 were investigated by a ball-on-disk friction tester in a vacuum chamber equipped with a quadrupole mass spectrometer (Q-MS). Ionic liquids exhibited better tribological properties than synthetic hydrocarbon oil (multialkylated cyclopentane (MAC)) in high vacuum conditions. The induction period for decomposition of MAC was about 10 km, while no obvious gaseous products were observed for ionic liquids even after a sliding distance of 22 km under the same mechanical conditions. The mass spectra indicated that both the anionic and cationic moieties of ionic liquids decomposed on the nascent steel surface during friction processes. The cationic moiety with a longer alkyl chain was more difficult to decompose on the nascent steel surface than that with a shorter alkyl chain. XPS analysis revealed that the tribofilm formed by ionic liquid was mainly composed of FeF 2 and FeS, which deactivated the nascent surface. As a result, desorption rate of gaseous products decreased appreciably comparing with MAC. The critical load for the mechanical activation of the decomposition correspondingly increased from 1.1 N of MAC to 8 N of ionic liquids.

  12. A new QM/MM method oriented to the study of ionic liquids.

    PubMed

    Sánchez, M Luz; Corchado, José C; Martín, M Elena; Galván, Ignacio Fdez; Barata-Morgado, Rute; Aguilar, Manuel A

    2015-09-30

    The interest on room temperature ionic liquids has grown in the last decades because of their use as all-purpose solvent and their low environmental impact. In the present work, a new theoretical procedure is developed to study pure ionic liquids within the framework of the quantum mechanics/molecular mechanics method. Each type of ion (cation or anion) is considered as an independent entity quantum mechanically described that follows a differentiated path in the liquid. The method permits, through an iterative procedure, the full coupling between the polarized charge distribution of the ions and the liquid structure around them. The procedure has been tested with 1-ethyl-3-methylimidazolium tetrafluoroborate. It was found that, similar to non-polar liquids and as a consequence of the low value of the reaction field, the cation and anion charge distributions are hardly polarized by the rest of molecules in the liquid. Their structure is characterized by an alternance between anion and cation shells as evidenced by the coincidence of the first maximum of the anion-anion and cation-cation radial distribution functions with the first minimum of the anion-cation. Some degree of stacking between the cations is also found. PMID:26213207

  13. Isolation and Characterisation of 1-Alkyl-3-Methylimidazolium Chloride Ionic Liquid-Tolerant and Biodegrading Marine Bacteria

    PubMed Central

    Megaw, Julianne; Busetti, Alessandro; Gilmore, Brendan F.

    2013-01-01

    The aim of this study was to isolate and identify marine-derived bacteria which exhibited high tolerance to, and an ability to biodegrade, 1-alkyl-3-methylimidazolium chloride ionic liquids. The salinity and hydrocarbon load of some marine environments may induce selective pressures which enhance the ability of microbes to grow in the presence of these liquid salts. The isolates obtained in this study generally showed a greater ability to grow in the presence of the selected ionic liquids compared to microorganisms described previously, with two marine-derived bacteria, Rhodococcus erythropolis and Brevibacterium sanguinis growing in concentrations exceeding 1 M 1-ethyl-3-methylimidazolium chloride. The ability of these bacteria to degrade the selected ionic liquids was assessed using High Performance Liquid Chromatography (HPLC), and three were shown to degrade the selected ionic liquids by up to 59% over a 63-day test period. These bacterial isolates represent excellent candidates for further potential applications in the bioremediation of ionic liquid-containing waste or following accidental environmental exposure. PMID:23560109

  14. Characterization of ionic liquid pretreated aspen wood using semi-quantitative methods for ethanol production.

    PubMed

    Goshadrou, Amir; Karimi, Keikhosro; Lefsrud, Mark

    2013-07-25

    Aspen wood (Populus tremula) was pretreated with ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) and dilute sulfuric acid for improvement of ethanol production. The ionic liquid pretreatment included wood dissolution at 120°C and 5% solid loading for 1, 3, and 5h followed by regeneration using water as an anti-solvent. More than 95% enzymatic digestibility was achieved for the ionic liquid treated wood, while the yield from the untreated wood was only 5.3%. Furthermore, over 81% of the maximum theoretical ethanol yield was attained after 24h fermentation of the ionic liquid treated wood, whereas the yields were only 5.3% and 42.1% for the untreated and dilute acid treated materials, respectively. A side-by-side comparative analysis of the pretreated materials using semi-quantitative techniques (e.g., Simons' staining and enzyme adsorption) revealed that the ionic liquid treatment was much more successful in increasing the cellulose accessibility to cellulases and decreasing the lignin content. PMID:23768585

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

    NASA Astrophysics Data System (ADS)

    Cha, E. H.; Lim, S. A.; Park, J. H.; Kim, D. W.; Macfarlane, D. R.

    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 1134TCM) 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 × 10 -3 S cm -1 at 25 °C) exhibits about over four times higher than that of homopolymer system (PAMPSLi/emImTCM: 1.28 × 10 -3 S cm -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 1134TCM (2.48 × 10 -3 S cm -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 1134TCM (28.61 cP). Low viscosity leads to a fast rate of diffusion of redox species.

  16. Novel polymer electrolytes based on gelatin and ionic liquids

    NASA Astrophysics Data System (ADS)

    Leones, Rita; Sentanin, F.; Rodrigues, Luísa C.; Ferreira, Rute A. S.; Marrucho, Isabel M.; Esperança, José M. S. S.; Pawlicka, Agnieszka; Carlos, Luís D.; Manuela Silva, M.

    2012-12-01

    This study describes the results of the characterization of polymer electrolytes using gelatin matrix doped with europium triflate and/or different ionic liquids. Samples of solvent-free electrolytes were prepared and characterized by ionic conductivity measurements, thermal analysis, electrochemical stability, X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence spectroscopy. Electrolyte samples are thermally stable up to approximately 220 °C. All the materials synthesized are totally amorphous. The room temperature conductivity maximum of this electrolyte system is based on ionic liquid 1-ethyl-3-methylimidazolium acetate, (C2mim)(OAc) (1.18 × 10-4 S cm-1 at 30 °C). The electrochemical stability domain of all samples is about 2.0 V versus Li/Li+. This new series of materials represents a promising alternative in polymer electrolytes research field. The preliminary studies carried out with electrochromic devices (ECDs) incorporating optimized compositions have confirmed that these materials may perform as satisfactory multifunctional component layers in the field of "smart windows". This new materials, will open a land of promising applications in many areas: optics, energy, medicine for example as membranes and separation devices, ECD-based devices, sensors, etc.

  17. Thermoelectric energy recovery at ionic-liquid/electrode interface.

    PubMed

    Bonetti, Marco; Nakamae, Sawako; Huang, Bo Tao; Salez, Thomas J; Wiertel-Gasquet, Cécile; Roger, Michel

    2015-06-28

    A thermally chargeable capacitor containing a binary solution of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)-imide in acetonitrile is electrically charged by applying a temperature gradient to two ideally polarisable electrodes. The corresponding thermoelectric coefficient is -1.7 mV/K for platinum foil electrodes and -0.3 mV/K for nanoporous carbon electrodes. Stored electrical energy is extracted by discharging the capacitor through a resistor. The measured capacitance of the electrode/ionic-liquid interface is 5 μF for each platinum electrode while it becomes four orders of magnitude larger, ≈36 mF, for a single nanoporous carbon electrode. Reproducibility of the effect through repeated charging-discharging cycles under a steady-state temperature gradient demonstrates the robustness of the electrical charging process at the liquid/electrode interface. The acceleration of the charging by convective flows is also observed. This offers the possibility to convert waste-heat into electric energy without exchanging electrons between ions and electrodes, in contrast to what occurs in most thermogalvanic cells. PMID:26133450

  18. Thermoelectric energy recovery at ionic-liquid/electrode interface

    NASA Astrophysics Data System (ADS)

    Bonetti, Marco; Nakamae, Sawako; Huang, Bo Tao; Salez, Thomas J.; Wiertel-Gasquet, Cécile; Roger, Michel

    2015-06-01

    A thermally chargeable capacitor containing a binary solution of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)-imide in acetonitrile is electrically charged by applying a temperature gradient to two ideally polarisable electrodes. The corresponding thermoelectric coefficient is -1.7 mV/K for platinum foil electrodes and -0.3 mV/K for nanoporous carbon electrodes. Stored electrical energy is extracted by discharging the capacitor through a resistor. The measured capacitance of the electrode/ionic-liquid interface is 5 μF for each platinum electrode while it becomes four orders of magnitude larger, ≈36 mF, for a single nanoporous carbon electrode. Reproducibility of the effect through repeated charging-discharging cycles under a steady-state temperature gradient demonstrates the robustness of the electrical charging process at the liquid/electrode interface. The acceleration of the charging by convective flows is also observed. This offers the possibility to convert waste-heat into electric energy without exchanging electrons between ions and electrodes, in contrast to what occurs in most thermogalvanic cells.

  19. Weighing the surface charge of an ionic liquid.

    PubMed

    Hjalmarsson, Nicklas; Wallinder, Daniel; Glavatskih, Sergei; Atkin, Rob; Aastrup, Teodor; Rutland, Mark W

    2015-10-14

    Electrochemical quartz crystal microbalance has been used to measure changes in the composition of the capacitive electrical double layer for 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)-trifluorophosphate, an ionic liquid, in contact with a gold electrode surface as a function of potential. The mass difference between the cation and anion means that the technique can effectively "weigh" the surface charge accurately with high temporal resolution. This reveals quantitatively how changing the potential alters the ratio of cations and anions associated with the electrode surface, and thus the charge per unit area, as well as the kinetics associated with these interfacial processes. The measurements reveal that it is diffusion of co-ions into the interfacial region rather than expulsion of counterions that controls the relaxation. The measured potential dependent double layer capacitance experimentally validates recent theoretical predictions for counterion overscreening (low potentials) and crowding (high potentials) at electrode surfaces. This new capacity to quantitatively measure ion composition is critical for ionic liquid applications ranging from batteries, capacitors and electrodeposition through to boundary layer structure in tribology, and more broadly provides new insight into interfacial processes in concentrated electrolyte solutions. PMID:26370450

  20. Thermoelectric energy recovery at ionic-liquid/electrode interface

    SciTech Connect

    Bonetti, Marco; Nakamae, Sawako; Huang, Bo Tao; Wiertel-Gasquet, Cécile; Roger, Michel; Salez, Thomas J.

    2015-06-28

    A thermally chargeable capacitor containing a binary solution of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)-imide in acetonitrile is electrically charged by applying a temperature gradient to two ideally polarisable electrodes. The corresponding thermoelectric coefficient is −1.7 mV/K for platinum foil electrodes and −0.3 mV/K for nanoporous carbon electrodes. Stored electrical energy is extracted by discharging the capacitor through a resistor. The measured capacitance of the electrode/ionic-liquid interface is 5 μF for each platinum electrode while it becomes four orders of magnitude larger, ≈36 mF, for a single nanoporous carbon electrode. Reproducibility of the effect through repeated charging-discharging cycles under a steady-state temperature gradient demonstrates the robustness of the electrical charging process at the liquid/electrode interface. The acceleration of the charging by convective flows is also observed. This offers the possibility to convert waste-heat into electric energy without exchanging electrons between ions and electrodes, in contrast to what occurs in most thermogalvanic cells.

  1. Selective solid-phase extraction of alpha-tocopherol by functionalized ionic liquid-modified mesoporous SBA-15 adsorbent.

    PubMed

    Li, Min; Pham, Patrisha J; Pittman, Charles U; Li, Tingyu

    2008-10-01

    Ordered mesoporous adsorbents were prepared by physically grafting functionalized ionic liquids onto SBA-15 (a mesoporous siliceous substrate) using incipient wetness immersion method. These adsorbents were successfully applied to the selective extraction and separation of alpha-tocopherol (an isomer of vitamin E) from a model mixture of soybean oil deodorizer distillate. Various parameters affecting adsorption process such as adsorption time, the structures and loadings of ionic liquids, the adsorption isotherm, and the reusability of adsorbent were investigated using liquid-solid extraction. As high as 211 mg/g adsorbent of the adsorption capacity for alpha-tocopherol was obtained through the adsorption isotherm tests using [emim][Gly]/SBA-15 (functionalized ionic liquid 1-ethyl-3-methylimidazolium glycine which was physically coated on SBA-15) as the adsorbent, in which the functionalized ionic liquids contained the amino acid glycine as the anion. The adsorbent [emim][Gly]/SBA-15 also exhibited a very high adsorption selectivity for alpha-tocopherol. The extraction selectivity or the ratio of distribution coefficients between alpha-tocopherol and the major interference component glyceryl triundecanoate (K(d(alpha-tocopherol))/K(d(triglyceride))) was 10.5. The concentration of alpha-tocopherol was significantly increased from 15.6% in original feedstock solution that contained fatty acid methyl ester, triglyceride and alpha-tocopherol to 73.0% after stripping by diethyl ether. Five adsorbent recycle tests showed good reusability of the functionalized ionic liquid-modified mesoporous adsorbent. PMID:18845881

  2. Tuning the theta temperature and critical micellization temperature of polymers in ionic liquids

    NASA Astrophysics Data System (ADS)

    Lodge, Timothy; Hoarfrost, Megan

    2014-03-01

    Ionic liquids feature a combination of properties that make them very interesting solvents for polymers, but questions remain regarding the thermodynamics of polymer/ionic liquid solutions. In this work, the lower-critical-solution-temperature (LCST) phase behavior of poly(n-butyl methacrylate) (PnBMA) in mixtures of the ionic liquids 1-butyl-3-methylimidazolium: bis(trifluoromethylsulfonyl)imide ([BMIm][TFSI]) and 1-ethyl-3-methylimidazolium:TFSI ([EMIm][TFSI]) is characterized by transmittance, light scattering, and small-angle neutron scattering measurements. Relevant thermodynamic parameters are readily tuned by varying the ionic liquid composition. In particular, the cloud point, spinodal, and theta temperatures are all found to increase linearly with [BMIm] content. The interaction parameters are determined as a function of temperature and concentration using three different methods, and the results from each method are compared. The theta temperatures are then compared quantitatively to the critical micellization temperatures (CMTs) for PnBMA-poly(ethylene oxide) diblocks, to test the proposition that the CMT corresponds to a fixed value of chi.

  3. Synthesis and characterization of ionic liquid (EMImBF4)/Li+ - chitosan membranes for ion battery

    NASA Astrophysics Data System (ADS)

    Pasaribu, Marvin H.; Arcana, I. Made; Wahyuningrum, Deana

    2015-09-01

    Lithium ion battery has been currently developed and produced because it has a longer life time, high energycapacity, and the efficient use of lithium ion battery that is suitable for storing electrical energy. However, this battery has some drawbacks such as use liquid electrolytes that are prone to leakage and flammability during the battery charging process in high temperature. In this study, an ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) containing Li+ ions was synthesized and combined with chitosan polymer host as a polymer electrolyte membrane for lithium-ion batteries to solve this problems. This ionic liquid was obtained from the anion metathesis reaction between EMImBr and LiBF4 salt, while EMImBr was synthesized from the reaction between 1-methylimidazole and ethyl bromide utilizing Microwave Assisted Organic Synthesis (MAOS) method. The ionic liquid obtained was characterized by microstructure analysis with using NMR and FTIR spectroscopy. The polymer electrolyte membrane was characterized by analysis functional groups (FTIR), ionic conductivity (EIS), and surface morphology (SEM). The analysis results of ion conductivity by the EIS method showed the increase the ionic conductivity value of membranes from 1.30 × 10-2 S cm- 1 for chitosan to 1.30 × 10-2 S cm-1 for chitosan with EMImBF4/Li+, and this result was supported by analysis the surface morphology (SEM).

  4. Electrochemical studies of hydrogen chloride gas in several room temperature ionic liquids: mechanism and sensing.

    PubMed

    Murugappan, Krishnan; Silvester, Debbie S

    2016-01-28

    The electrochemical behaviour of highly toxic hydrogen chloride (HCl) gas has been investigated in six room temperature ionic liquids (RTILs) containing imidazolium/pyrrolidinium cations and range of anions on a Pt microelectrode using cyclic voltammetry (CV). HCl gas exists in a dissociated form of H(+) and [HCl2](-) in RTILs. A peak corresponding to the oxidation of [HCl2](-) was observed, resulting in the formation of Cl2 and H(+). These species were reversibly reduced to H2 and Cl(-), respectively, on the cathodic CV scan. The H(+) reduction peak is also present initially when scanned only in the cathodic direction. In the RTILs with a tetrafluoroborate or hexafluorophosphate anion, CVs indicated a reaction of the RTIL with the analyte/electrogenerated products, suggesting that these RTILs might not be suitable solvents for the detection of HCl gas. This was supported by NMR spectroscopy experiments, which showed that the hexafluorophosphate ionic liquid underwent structural changes after HCl gas electrochemical experiments. The analytical utility was then studied in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][NTf2]) by utilising both peaks (oxidation of [HCl2](-) and reduction of protons) and linear calibration graphs for current vs. concentration for the two processes were obtained. The reactive behaviour of some ionic liquids clearly shows that the choice of the ionic liquid is very important if employing RTILs as solvents for HCl gas detection. PMID:26697927

  5. Capacitance of Ti3C2Tx MXene in ionic liquid electrolyte

    NASA Astrophysics Data System (ADS)

    Lin, Zifeng; Barbara, Daffos; Taberna, Pierre-Louis; Van Aken, Katherine L.; Anasori, Babak; Gogotsi, Yury; Simon, Patrice

    2016-09-01

    Ti3C2Tx MXene, a two-dimensional (2D) early transition metal carbide, has shown an extremely high volumetric capacitance in aqueous electrolytes, but in a narrow voltage window (less than 1.23 V). The utilization of MXene materials in ionic liquid electrolytes with a large voltage window has never been addressed. Here, we report the preparation of the Ti3C2Tx MXene ionogel film by vacuum filtration for use as supercapacitor electrodes operating in 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMI-TFSI) neat ionic liquid electrolyte. Due to the disordered structure of the Ti3C2Tx hydrogel film and a stable spacing after vacuum drying, achieved through ionic liquid electrolyte immersion of the Ti3C2Tx hydrogel film, the Ti3C2Tx surface became accessible to EMI+ and TFSI- ions. A capacitance of 70 F g-1 together with a large voltage window of 3 V was obtained at a scan rate of 20 mV s-1 in neat EMI-TFSI electrolyte. The electrochemical signature indicates a capacitive behavior even at a high scan rate (500 mV s-1) and a high power performance. This work opens up the possibilities of using MXene materials with various ionic liquid electrolytes.

  6. Lyotropic Phase Behavior of Polybutadiene-Poly(ethylene oxide) Diblock Copolymers in Ionic Liquids

    SciTech Connect

    Simone, Peter M.; Lodge, Timothy P.

    2008-08-26

    The lyotropic phase behavior of three poly(1,2-butadiene-b-ethylene oxide) diblock copolymers (PB-PEO) with different monomer volume fractions has been studied in two different ionic liquids, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMI][TFSI]) and 1-butyl-3-methylimidazolium hexafluorophosphate ([BMI][PF{sub 6}]), across the complete concentration range. The ordered microstructures present in the solutions were characterized via small-angle X-ray scattering (SAXS). The phase diagrams for the PB-PEO/ionic liquid solutions include regions corresponding to the classical copolymer microstructures: body-centered-cubic lattices of spheres, hexagonally ordered cylinders, and lamellae. Additionally, the phase diagrams also include wide regions of coexisting microstructures and regions apparently corresponding to a disordered network microstructure. The phase behavior of the PB-PEO copolymers in both ionic liquids was comparable to their previously reported aqueous solution behavior. The temperature dependence of the phase diagrams was very modest, indicative of a highly segregated system. The level of solvent selectivity was also investigated via cryogenic transmission electron microscopy (cryo-TEM) on dilute solutions. On the basis of the morphology of the dilute solution copolymer aggregate structures in the ionic liquid solvents, and on the structural length scales of the concentrated solutions, it was concluded that for PB-PEO [BMI][PF{sub 6}] behaves as a more selective solvent than [EMI][TFSI].

  7. Mass and Charge Transport in the Polymer-Ionic-Liquid System PEO-EMImI: From Ionic-Liquid-in-Polymer to Polymer-in-Ionic-Liquid Electrolytes.

    PubMed

    Kösters, Johannes; Schönhoff, Monika; Stolwijk, Nicolaas A

    2015-04-30

    Conventional polymer electrolytes based on inorganic salts are commonly characterized and utilized over a small salt-poor composition range because of phase transitions accompanied by loss of ion conductivity at high salt concentrations. By contrast, well-chosen polymer-ionic-liquid (IL) systems offer the possibility to vary the IL content from the IL-in-polymer to the polymer-in-IL domain. We have investigated the temperature-dependent ionic conductivity in PEOyEMImI systems consisting of poly(ethylene oxide) complexed with 1-ethyl-3-methylimidazolium iodide for y = EO/IL ratios ranging from 0.6 to 60 and compared diffusivity data with that arising from (1)H pulsed-field-gradient nuclear magnetic resonance for EMIm and (125)I radiotracer diffusion for iodine. Surprisingly, the diffusivity of cations and anions vary at most by 50% at fixed temperatures over the entire composition range. The much larger changes in the charge diffusivity Dσ relate to ion pairing exhibiting a minimum near the intermediate composition y = 10. Altogether, the results are relevant to application in dye-sensitized solar cells and show that a high ion density is crucial to enhance the iodine transport capacity. PMID:25848686

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

    PubMed Central

    2012-01-01

    Background 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), still relatively new class of solvents, are attractive for biomass pretreatment because some demonstrate the rare ability to dissolve all components of lignocellulosic biomass including highly ordered (crystalline) cellulose. In the present study, three ILs, 1-butyl-3-methylimidazolium chloride ([C4mim]Cl), 1-ethyl-3-methylimidazolium chloride ([C2mim]Cl), 1-ethyl-3-methylimidazolium acetate ([C2mim]OAc) are used to dissolve/pretreat and fractionate sugarcane bagasse. In these IL-based pretreatments the biomass is completely or partially dissolved in ILs at temperatures greater than 130°C and then precipitated by the addition of an antisolvent to the IL biomass mixture. For the first time mass balances of IL-based pretreatments are reported. Such mass balances, along with kinetics data, can be used in process modelling and design. Results Lignin removals of 10% mass of lignin in bagasse with [C4mim]Cl, 50% mass with [C2mim]Cl and 60% mass with [C2mim]OAc, are achieved by limiting the amount of water added as antisolvent to 0.5 water:IL mass ratio thus minimising lignin precipitation. Enzyme saccharification (24 h, 15FPU) yields (% cellulose mass in starting bagasse) from the recovered solids rank as: [C2mim]OAc(83%) > >[C2mim]Cl(53%) = [C4mim]Cl(53%). Composition of [C2mim]OAc-treated solids such as low lignin, low acetyl group content and preservation of arabinosyl groups are characteristic of aqueous alkali pretreatments while those of chloride IL-treated solids resemble aqueous acid pretreatments. All ILs are fully recovered after use (100% mass as determined by ion chromatography). Conclusions In all three ILs regulated addition of water as an antisolvent effected a polysaccharide enriched precipitate since some of the lignin remained dissolved

  9. Effect of ionic liquid treatment on the ultrastructural and topochemical features of compression wood in Japanese cedar (Cryptomeria japonica).

    PubMed

    Kanbayashi, Toru; Miyafuji, Hisashi

    2016-01-01

    The morphological and topochemical changes in wood tissues in compression wood of Japanese cedar (Cryptomeria japonica) upon treated with two types of ionic liquids, 1-ethyl-3-methylimidazolium chloride ([C2mim][Cl]) and 1-ethylpyridinium bromide ([EtPy][Br]) were investigated. Compression wood tracheids were swollen by both ionic liquids but their swelling behaviors were different in the types of ionic liquids used. Under the polarized light, we confirmed that crystalline cellulose in compression wood is amorphized by [C2mim][Cl] treatment whereas it changes slightly by [EtPy][Br] treatment. Raman microscopic analyses revealed that [C2mim][Cl] can preferentially liquefy polysaccharides in compression wood whereas [EtPy][Br] liquefy lignin. In addition, the interaction of compression wood with ionic liquids is different for the morphological regions. These results will assist in the use of ionic liquid treatment of woody biomass to produce valuable chemicals, bio-fuels, bio-based composites and other products. PMID:27426470

  10. Combined use of ionic liquid and hydroxypropyl-β-cyclodextrin for the enantioseparation of ten drugs by capillary electrophoresis.

    PubMed

    Cui, Yan; Ma, Xiaowei; Zhao, Min; Jiang, Zhen; Xu, Shuying; Guo, Xingjie

    2013-07-01

    In the present study, hydroxypropyl-β-cyclodextrin and an ionic liquid (1-ethyl-3-methylimidazolium-l-lactate) were used as additives in capillary electrophoresis for the enantioseparation of 10 analytes, including ofloxacin, propranolol hydrochloride, dioxopromethazine hydrochloride, isoprenaline hydrochloride, chlorpheniramine maleate, liarozole, tropicamide, amlodipine benzenesulfonate, brompheniramine maleate, and homatropine methylbromide. The effects of ionic liquid concentrations, salt effect, cations, and anions of ionic liquids on enantioseparation were investigated and the results proved that there was a synergistic effect between hydroxypropyl-β-cyclodextrin and the ionic liquid, and the cationic part of the ionic liquid played an important role in the increased resolution. With the developed dual system, all the enantiomers of 10 analytes were well separated in resolutions of 5.35, 1.76, 1.85, 2.48, 2.88, 1.43, 5.45, 4.35, 2.76, and 2.98, respectively. In addition, the proposed method was applied to the determination of the enantiomeric purity of S-ofloxacin after validation of the method in terms of selectivity, repeatability, linearity range, accuracy, precision, limit of detection (LOD), and limit of quality (LOQ). PMID:23740623

  11. Effect of ionic liquid treatment on the ultrastructural and topochemical features of compression wood in Japanese cedar (Cryptomeria japonica)

    PubMed Central

    Kanbayashi, Toru; Miyafuji, Hisashi

    2016-01-01

    The morphological and topochemical changes in wood tissues in compression wood of Japanese cedar (Cryptomeria japonica) upon treated with two types of ionic liquids, 1-ethyl-3-methylimidazolium chloride ([C2mim][Cl]) and 1-ethylpyridinium bromide ([EtPy][Br]) were investigated. Compression wood tracheids were swollen by both ionic liquids but their swelling behaviors were different in the types of ionic liquids used. Under the polarized light, we confirmed that crystalline cellulose in compression wood is amorphized by [C2mim][Cl] treatment whereas it changes slightly by [EtPy][Br] treatment. Raman microscopic analyses revealed that [C2mim][Cl] can preferentially liquefy polysaccharides in compression wood whereas [EtPy][Br] liquefy lignin. In addition, the interaction of compression wood with ionic liquids is different for the morphological regions. These results will assist in the use of ionic liquid treatment of woody biomass to produce valuable chemicals, bio-fuels, bio-based composites and other products. PMID:27426470

  12. Engineering ionic liquid-tolerant cellulases for biofuels production.

    PubMed

    Wolski, Paul W; Dana, Craig M; Clark, Douglas S; Blanch, Harvey W

    2016-04-01

    Dissolution of lignocellulosic biomass in certain ionic liquids (ILs) can provide an effective pretreatment prior to enzymatic saccharification of cellulose for biofuels production. Toward the goal of combining pretreatment and enzymatic hydrolysis, we evolved enzyme variants of Talaromyces emersonii Cel7A to be more active and stable than wild-type T. emersonii Cel7A or Trichoderma reesei Cel7A in aqueous-IL solutions (up to 43% (w/w) 1,3-dimethylimdazolium dimethylphosphate and 20% (w/w) 1-ethyl-3-methylimidazolium acetate). In general, greater enzyme stability in buffer at elevated temperature corresponded to greater stability in aqueous-ILs. Post-translational modification of the N-terminal glutamine residue to pyroglutamate via glutaminyl cyclase enhanced the stability of T. emersonii Cel7A and variants. Differential scanning calorimetry revealed an increase in melting temperature of 1.9-3.9°C for the variant 1M10 over the wild-type T. emersonii Cel7A in aqueous buffer and in an IL-aqueous mixture. We observed this increase both with and without glutaminyl cyclase treatment of the enzymes. PMID:26819239

  13. Tertiary phase diagram of cellulose, ionic liquid and organic solvent

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Henderson, Doug; Tyagi, Madhusudan; Mao, Yimin; Briber, Robert M.; Wang, Howard

    Cellulose is the most abundant natural polymer on earth, and widely used in products from clothing to paper. Fundamental understanding of molecular solutions of cellulose is the key to realize advanced technologies beyond cellulose fibers. It has been reported that certain ionic liquid/organic solvent mixtures dissolve cellulose. In this study, the tertiary phase diagram of microcrystalline cellulose, 1-Ethyl-3-methylimidazolium acetate (EMIMAc), and dimethylformamide (DMF) mixtures has been determined using optical cloud point method and small angle neutron scattering (SANS). Data indicate that a molar ratio of EMIMAc to cellulose repeating unit equal or greater than 3 is necessary but not sufficient in forming one-phase homogeneous solutions. A miscibility gap exists in the dilute regime, where a minimum of 5 mol% of EMIM Ac in DMF is needed to form homogenous solutions. SANS show that cellulose chains adopt Gaussian-like conformation in homogenous solutions. The solutions exhibit the characteristics of upper critical solution temperature. Clustering of cellulose chains occurs at low EMIMAc/DMF or EMIMAc/cellulose ratio, or at low temperatures. The mechanism of cellulose dissolution in tertiary mixture is discussed.

  14. Ionic liquid/ultrasound pretreatment and in situ enzymatic saccharification of bagasse using biocompatible cholinium ionic liquid.

    PubMed

    Ninomiya, Kazuaki; Kohori, Asami; Tatsumi, Mai; Osawa, Koji; Endo, Takatsugu; Kakuchi, Ryohei; Ogino, Chiaki; Shimizu, Nobuaki; Takahashi, Kenji

    2015-01-01

    Choline acetate (ChOAc), a cholinium ionic liquid (IL), showed almost the same bagasse pretreatment capability as 1-ethyl-3-methylimidazolium acetate (EmimOAc), a conventional imidazolium IL used for biomass pretreatment. Moreover, ChOAc showed less of an inhibitory effect on cellulase than EmimOAc. Thus, ChOAc was used for IL/ultrasound-assisted pretreatment and in situ enzymatic saccharification, where IL was not washed out from the pretreated bagasse but diluted with the addition of a buffer solution. When in situ saccharification was performed for 48h in the presence of 10% ChOAc, the cellulose and hemicellulose saccharification percentages were 80% and 72%, respectively. When ChOAc was increased to 20%, the saccharification percentages were 72% and 53%, respectively. However, the values were just 28% and 2%, respectively, in case of 20% EmimOAc. A glucose/xylose solution free from IL and ChOAc aqueous solution without these sugars could be recovered separately by electrodialysis of the hydrolysate of in situ saccharification. PMID:25460999

  15. Lithium-sulphur battery with activated carbon cloth-sulphur cathode and ionic liquid as electrolyte

    NASA Astrophysics Data System (ADS)

    Swiderska-Mocek, Agnieszka; Rudnicka, Ewelina

    2015-01-01

    In this study a binder-free activated carbon cloth-sulphur (ACC-S) composite cathode is presented. Such a cathode was obtained using the impregnating technique of microporous activated carbon cloth with elemental melted sulphur. The surface morphology of an activated carbon cloth-sulphur electrode was studied using a scanning electron microscope (SEM), which was equipped with an EDX spectroscopy attachment. Electrochemical properties of the ACC-S composite cathode was tested in an ionic liquid electrolyte consisting of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulphonyl)imide (EtMeImNTf2) and bis(trifluoromethanesulphonyl)imide (LiNTf2). The ACC-sulphur cathode working together with lithium anode was tested with the use of cyclic voltammetry (CV), galvanostatic charge/discharge cycles and electrochemical impedance spectroscopy (EIS). The capacity and cyclic stability of the ACC-S composite cathode were much better than those for the sulphur cathode (a mixture of sulphur from graphene nanoplatelets and carbon black) tested in the same ionic liquid electrolyte. The ACC-sulphur cathode showed good cyclability and coulombic efficiency (99%) with the ionic liquid electrolyte. The reversible capacity of the ACC-S|electrolyte|Li cell was ca. 830 mAh g-1 after 50 cycles.

  16. Acetylcholinesterase biosensor for carbamate drugs based on tetrathiafulvalene-tetracyanoquinodimethane/ionic liquid conductive gels.

    PubMed

    Zamfir, Lucian-Gabriel; Rotariu, Lucian; Bala, Camelia

    2013-08-15

    A highly sensitive acetylcholinesterase biosensor was developed for detection of carbamate drugs based on TTF-TCNQ-ionic liquid gel thiocholine sensor. The TTF-TCNQ-ionic/ionic liquid gel was characterized by FT-IR and scanning electron microscopy. The electrocatalytic behavior of TTF-TCNQ-ionic liquid gels toward oxidation of thiocholine was thoroughly investigated. 1-Ethyl-3-methylimidazolium tetracyanoborate gel based sensor allowed amperometric detection of thiocholine at +400 mV vs. Ag/AgCl with a high sensitivity of 55.9±1.2 μA mM(-1)cm(-2) and a low detection limit equal to 7.6 μM. The catalytic rate constant and diffusion constant of thiocholine were estimated from chronoamperometric data. The proposed biosensor based on AChE immobilized in sol-gel matrix was used for the detection of two carbamate therapeutic drugs. Very low detection limits of 26 pM eserine and 0.3 nM neostigmine were achieved. The analysis of spiked tap water proved the biosensor capability to be used as a screening method for detection of carbamate drugs in wastewaters. PMID:23500478

  17. Interactions in the ionic liquid [EMIM][FAP]: a coupled experimental and computational analysis.

    PubMed

    Voroshylova, Iuliia V; Teixeira, Filipe; Costa, Renata; Pereira, Carlos M; Cordeiro, M Natália D S

    2016-01-28

    Gas-phase electronic and structural properties of the room temperature ionic liquid 1-ethyl-3-methylimidazolium tris(perfluoroethyl)trifluorophosphate ([EMIM][FAP]) were studied using density functional theory, and confirmed with results from infrared spectroscopy. A conformational analysis allowed the identification of several plausible conformers of the ion pairs. For the detected conformers, the infrared spectra were predicted and their thermodynamic properties were evaluated. The topology of the electronic density of the most stable conformers of [EMIM][FAP] ion pairs were characterised using the quantum theory of atoms in molecules. A number of possible hydrogen bonds between the cations and anions of the ionic liquid were identified. Excellent correspondence was found between the predicted spectra of gas-phase [EMIM][FAP] conformers and the experimental infrared spectrum, which in turn allowed a clear attribution of the vibration modes of [EMIM][FAP]. Finally, the contribution of the various conformers of both isomers of the [FAP](-) anion to the ionic liquid macro-properties is shown. PMID:26699428

  18. Carbene formation upon reactive dissolution of metal oxides in imidazolium ionic liquids.

    PubMed

    Wellens, Sil; Brooks, Neil R; Thijs, Ben; Meervelt, Luc Van; Binnemans, Koen

    2014-03-01

    Metal oxides were found to dissolve in different imidazolium ionic liquids with a hydrogen atom in the C2 position of the imidazolium ring, but not if a methyl substituent was present in the C2 position. The crystal structure of the product that crystallised from an ionic liquid containing dissolved silver(i) oxide showed that this was a silver(i) carbene complex. The presence of carbenes in solution was proven by (13)C NMR spectroscopy and the reactions were also monitored by Raman spectroscopy. The dissolution of other metal oxides, namely copper(ii) oxide, zinc(ii) oxide and nickel(ii) oxide, was also studied in imidazolium ionic liquids and it was found that stable zinc(ii) carbenes were formed in solution, but these did not crystallise under the given experimental conditions. A crystalline nickel(ii) carbene complex could be obtained from a solution of nickel(ii) chloride dissolved in a mixture of 1-butyl-3-methylimidazolium and 1-ethyl-3-methylimidazolium acetate. PMID:24390601

  19. SEM Observation of Hydrous Superabsorbent Polymer Pretreated with Room-Temperature Ionic Liquids

    PubMed Central

    Tsuda, Tetsuya; Mochizuki, Eiko; Kishida, Shoko; Iwasaki, Kazuki; Tsunashima, Katsuhiko; Kuwabata, Susumu

    2014-01-01

    Room-temperature ionic liquid (RTIL), which is a liquid salt at or below room temperature, shows peculiar physicochemical properties such as negligible vapor pressure and relatively-high ionic conductivity. In this investigation, we used six types of RTILs as a liquid material in the pretreatment process for scanning electron microscope (SEM) observation of hydrous superabsorbent polymer (SAP) particles. Very clear SEM images of the hydrous SAP particles were obtained if the neat RTILs were used for the pretreatment process. Of them, tri-n-butylmethylphosphonium dimethylphosphate ([P4, 4, 4, 1][DMP]) provided the best result. On the other hand, the surface morphology of the hydrous SAP particles pretreated with 1-ethyl-3-methylimidazolium tetrafluoroborate ([C2mim][BF4]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]) was damaged. The results of SEM observation and thermogravimetry analysis of the hydrous SAP pretreated with the RTILs strongly suggested that most water in the SAP particles are replaced with RTIL during the pretreatment process. PMID:24621609

  20. Peptides in the presence of aqueous ionic liquids: tunable co-solutes as denaturants or protectants?

    PubMed

    Lesch, Volker; Heuer, Andreas; Tatsis, Vasileios A; Holm, Christian; Smiatek, Jens

    2015-10-21

    We studied the stability of a small β-hairpin peptide under the influence of an aqueous 1-ethyl-3-methylimidazolium acetate ([EMIM](+)[ACE](-)) solution via all-atom molecular dynamics simulations in combination with metadynamics. Our free energy results indicate a denaturation of the peptide structure in the presence of the ionic liquid which is validated by a significant broadening of the end-to-end distance. The radial distribution functions between the ions and the peptide were used for the calculation of the preferential binding coefficients in terms of the Kirkwood-Buff theory. A significant structure dependent binding behavior of acetate to the peptide was found which can be interpreted as the main reason for the denaturation of the native conformation. The outcomes of our simulations allow us to propose a simple mechanism to explain the unfolding of the peptide with regard to the specific properties of ionic liquids. Our results are in good agreement with experimental findings and demonstrate the benefits of ionic liquids as tunable co-solutes with regard to their influence on protein structural properties. PMID:26377364

  1. Flexible thin-film battery based on solid-like ionic liquid-polymer electrolyte

    NASA Astrophysics Data System (ADS)

    Li, Qin; Ardebili, Haleh

    2016-01-01

    The development of high-performance flexible batteries is imperative for several contemporary applications including flexible electronics, wearable sensors and implantable medical devices. However, traditional organic liquid-based electrolytes are not ideal for flexible batteries due to their inherent safety and stability issues. In this study, a non-volatile, non-flammable and safe ionic liquid (IL)-based polymer electrolyte film with solid-like feature is fabricated and incorporated in a flexible lithium ion battery. The ionic liquid is 1-Ethyl-3-methylimidazolium dicyanamide (EMIMDCA) and the polymer is composed of poly(vinylidene fluoride-co-hexafluoropropene) (PVDF-HFP). The electrolyte exhibits good thermal stability (i.e. no weight loss up to 300 °C) and relatively high ionic conductivity (6 × 10-4 S cm-1). The flexible thin-film lithium ion battery based on solid-like electrolyte film is encapsulated using a thermal-lamination process and demonstrates excellent electrochemical performance, in both flat and bent configurations.

  2. Lysozyme Solubility and Conformation in Neat Ionic Liquids and Their Mixtures with Water.

    PubMed

    Strassburg, Stephen; Bermudez, Harry; Hoagland, David

    2016-06-13

    The room temperature solubility of a number of model proteins is assessed for a diverse set of neat ionic liquids (ILs). For two soluble protein-IL pairs, lysozyme in [C2MIM][EtSO4] (1-ethyl-3-methylimidazolium ethylsulfate) and in [C2,4,4,4P][Et2PO4] (tributyl(ethyl)phosphonium diethylphosphate), protein solubility and structure at various temperatures are probed by dynamic light scattering (assessing dissolved molecular size), turbidimetry (reflecting degree of solubility), and Fourier transform infrared spectroscopy (uncovering helical secondary structure). As compared to aqueous environments, [C2,4,4,4P][Et2PO4] thermally stabilizes protein size and secondary structure while [C2MIM][EtSO4] does the opposite. Lysozyme denatured in [C2MIM][EtSO4] does not aggregate, presumably due to an absence of hydrophobic interactions, and the denaturation appears thermally reversible. Both ILs at room temperature are miscible with water in all proportions, but to create the corresponding ternary mixtures with protein, the order of mixing is important. Mixed to avoid additions of water to IL-dissolved protein, stable solutions are obtained with [C2MIM][EtSO4] at all solvent compositions. When water is added to IL-rich solutions, liquid-liquid demixing is noted. PMID:27159556

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

    PubMed

    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. PMID:24793294

  4. Adsorbed and near surface structure of ionic liquids at a solid interface.

    PubMed

    Segura, Juan José; Elbourne, Aaron; Wanless, Erica J; Warr, Gregory G; Voïtchovsky, Kislon; Atkin, Rob

    2013-03-01

    The structure of solid-ionic liquid (IL) interfaces has been characterised with unprecedented clarity by employing a range of atomic force microscopy (AFM) imaging techniques and tip pressures appropriate for the system under study. Soft contact and amplitude-modulation (AM) AFM imaging have been used to elucidate the lateral structure of ILs adsorbed onto mica, and in the near surface ion layers. Data is presented for ethylammonium nitrate (EAN) and 1-ethyl-3-methylimidazolium bis(trifluoro-methylsulfonyl)imide (EMIm TFSI). Whereas EAN is a protic IL that forms a nanostructured sponge phase in the bulk, EMIm TFSI is aprotic and has weak (or absent) bulk association structure. Comparison of results obtained for the two liquids elucidates how the strength of bulk liquid morphology effects lateral organisation at the surface, and any effect of IL class, i.e. protic versus aprotic. Imaging reveals EAN self assembles at the solid surface in a worm-like morphology, whereas EMIm cations adsorb in a more isolated fashion, but still in rows templated by the mica surface. To the authors' knowledge, the wormlike structures present at the EAN-mica interface are the smallest self-assembled aggregates ever imaged on a solid surface. PMID:23361257

  5. Effect of alkyl chain length and hydroxyl group functionalization on the surface properties of imidazolium ionic liquids.

    PubMed

    Pensado, Alfonso S; Costa Gomes, Margarida F; Canongia Lopes, José N; Malfreyt, Patrice; Pádua, Agílio A H

    2011-08-14

    Properties of the surface of ionic liquids, such as surface tension, ordering, and charge and density profiles, were studied using molecular simulation. Two types of modification in the molecular structure of imidazolium cations were studied: the length of the alkyl side chain and the presence of a polar hydroxyl group at the end of the side chain. Four ionic liquids were considered: 1-ethyl-3-methylimidazolium tetrafluoroborate, [C(2)C(1)im][BF(4)]; 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate, [C(2)OHC(1)im][BF(4)]; 1-octyl-3-methylimidazolium tetrafluoroborate, [C(8)C(1)im][BF(4)] and 1-(8-hydroxyoctyl)-3-methylimidazolium tetrafluoroborate, [C(8)OHC(1)im][BF(4)]. The surface tension was calculated using both mechanical and thermodynamic definitions, with consistent treatment of the long-range corrections. The simulations reproduce the available experimental values of surface tension with a maximum deviation of ±10%. This energetic characterization of the interface is completed by microscopic structural analysis of orientational ordering at the interface and density profiles along the direction normal to the interface. The presence of the hydroxyl group modifies the local structure at the interface, leading to a less organized liquid phase. The results allow us to relate the surface tension to the structural ordering at the liquid-vacuum interface. PMID:21643581

  6. The Effect of Ionic Liquid Pretreatment on the Bioconversion of Tomato Processing Waste to Fermentable Sugars and Biogas.

    PubMed

    Allison, Brittany J; Cádiz, Juan Canales; Karuna, Nardrapee; Jeoh, Tina; Simmons, Christopher W

    2016-08-01

    Tomato pomace is an abundant lignocellulosic waste stream from industrial tomato processing and therefore a potential feedstock for production of renewable biofuels. However, little research has been conducted to determine if pretreatment can enhance release of fermentable sugars from tomato pomace. Ionic liquids (ILs) are an emerging pretreatment technology for lignocellulosic biomass to increase enzymatic digestibility and biofuel yield while utilizing recyclable chemicals with low toxicity. In this study, pretreatment of tomato pomace with the ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) was investigated. Changes in pomace enzymatic digestibility were affected by pretreatment time and temperature. Certain pretreatment conditions significantly improved reducing sugar yield and hydrolysis time compared to untreated pomace. Compositional analyses suggested that pretreatment primarily removed water-soluble compounds and enriched for lignocellulose in pomace, with only subtle changes to the composition of the lignocellulose. While tomato pomace was effectively pretreated with [C2mim][OAc] to improve enzymatic digestibility, as of yet, unknown factors in the pomace caused ionic liquid pretreatment to negatively affect anaerobic digestion of pretreated material. This result, which is unique compared to similar studies on IL pretreatment of grasses and woody biomass, highlights the need for additional research to determine how the unique chemical composition of tomato pomace and other lignocellulosic fruit residues may interact with ionic liquids to generate inhibitors for downstream fermentation to biofuels. PMID:27039400

  7. Synthesis and characterization of ionic liquid (EMImBF{sub 4})/Li{sup +} - chitosan membranes for ion battery

    SciTech Connect

    Pasaribu, Marvin H. Arcana, I Made Wahyuningrum, Deana

    2015-09-30

    Lithium ion battery has been currently developed and produced because it has a longer life time, high energycapacity, and the efficient use of lithium ion battery that is suitable for storing electrical energy. However, this battery has some drawbacks such as use liquid electrolytes that are prone to leakage and flammability during the battery charging process in high temperature. In this study, an ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) containing Li{sup +} ions was synthesized and combined with chitosan polymer host as a polymer electrolyte membrane for lithium-ion batteries to solve this problems. This ionic liquid was obtained from the anion metathesis reaction between EMImBr and LiBF4 salt, while EMImBr was synthesized from the reaction between 1-methylimidazole and ethyl bromide utilizing Microwave Assisted Organic Synthesis (MAOS) method. The ionic liquid obtained was characterized by microstructure analysis with using NMR and FTIR spectroscopy. The polymer electrolyte membrane was characterized by analysis functional groups (FTIR), ionic conductivity (EIS), and surface morphology (SEM). The analysis results of ion conductivity by the EIS method showed the increase the ionic conductivity value of membranes from 1.30 × 10{sup −2} S cm{sup −1} for chitosan to 1.30 × 10{sup −2} S cm{sup −1} for chitosan with EMImBF4/Li{sup +}, and this result was supported by analysis the surface morphology (SEM)

  8. Direct extraction of genomic DNA from maize with aqueous ionic liquid buffer systems for applications in genetically modified organisms analysis.

    PubMed

    Gonzalez García, Eric; Ressmann, Anna K; Gaertner, Peter; Zirbs, Ronald; Mach, Robert L; Krska, Rudolf; Bica, Katharina; Brunner, Kurt

    2014-12-01

    To date, the extraction of genomic DNA is considered a bottleneck in the process of genetically modified organisms (GMOs) detection. Conventional DNA isolation methods are associated with long extraction times and multiple pipetting and centrifugation steps, which makes the entire procedure not only tedious and complicated but also prone to sample cross-contamination. In recent times, ionic liquids have emerged as innovative solvents for biomass processing, due to their outstanding properties for dissolution of biomass and biopolymers. In this study, a novel, easily applicable, and time-efficient method for the direct extraction of genomic DNA from biomass based on aqueous-ionic liquid solutions was developed. The straightforward protocol relies on extraction of maize in a 10 % solution of ionic liquids in aqueous phosphate buffer for 5 min at room temperature, followed by a denaturation step at 95 °C for 10 min and a simple filtration to remove residual biopolymers. A set of 22 ionic liquids was tested in a buffer system and 1-ethyl-3-methylimidazolium dimethylphosphate, as well as the environmentally benign choline formate, were identified as ideal candidates. With this strategy, the quality of the genomic DNA extracted was significantly improved and the extraction protocol was notably simplified compared with a well-established method. PMID:25381609

  9. Ionic-liquid-based, manual-shaking- and ultrasound-assisted, surfactant-enhanced emulsification microextraction for the determination of three fungicide residues in juice samples.

    PubMed

    Chen, Xiaochu; You, Xiangwei; Liu, Fengmao; Hou, Fan; Zhang, Xu

    2015-01-01

    A novel manual-shaking- and ultrasound-assisted surfactant-enhanced emulsification microextraction method was developed for the determination of three fungicides in juice samples. In this method, the ionic liquid, 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide, instead of a volatile organic solvent was used as the extraction solvent. The surfactant, NP-10, was used as an emulsifier to enhance the dispersion of the water-immiscible ionic liquid into an aqueous phase, which accelerated the mass transfer of the analytes. Organic dispersive solvent typically required in common dispersive liquid-liquid microextraction methods was not necessary. In addition, manual shaking for 15 s before ultrasound to preliminarily mix the extraction solvent and the aqueous sample could greatly shorten the time for dispersing the ionic liquid into aqueous solution by ultrasound irradiation. Several experimental parameters affecting the extraction efficiency, including type and volume of extraction solvent, type and concentration of surfactant, extraction time, and pH, were optimized. Under the optimized conditions, good linearity with the correlation coefficients (γ) higher than 0.9986 and high sensitivity with the limit of detection ranging from 0.4 to 1.6 μg/L were obtained. The average recoveries ranged from 61.4 to 86.0% for spiked juice, with relative standard deviations from 1.8 to 9.7%. The proposed method was demonstrated to be a simple, fast, and efficient method for the analysis of the target fungicides in juice samples. PMID:25394281

  10. Determining diffusion coefficients of ionic liquids by means of field cycling nuclear magnetic resonance relaxometry.

    PubMed

    Kruk, D; Meier, R; Rachocki, A; Korpała, A; Singh, R K; Rössler, E A

    2014-06-28

    Field Cycling Nuclear Magnetic Resonance (FC NMR) relaxation studies are reported for three ionic liquids: 1-ethyl-3- methylimidazolium thiocyanate (EMIM-SCN, 220-258 K), 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM-BF4, 243-318 K), and 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6, 258-323 K). The dispersion of (1)H spin-lattice relaxation rate R1(ω) is measured in the frequency range of 10 kHz-20 MHz, and the studies are complemented by (19)F spin-lattice relaxation measurements on BMIM-PF6 in the corresponding frequency range. From the (1)H relaxation results self-diffusion coefficients for the cation in EMIM-SCN, BMIM-BF4, and BMIM-PF6 are determined. This is done by performing an analysis considering all relevant intra- and intermolecular relaxation contributions to the (1)H spin-lattice relaxation as well as by benefiting from the universal low-frequency dispersion law characteristic of Fickian diffusion which yields, at low frequencies, a linear dependence of R1 on square root of frequency. From the (19)F relaxation both anion and cation diffusion coefficients are determined for BMIM-PF6. The diffusion coefficients obtained from FC NMR relaxometry are in good agreement with results reported from pulsed- field-gradient NMR. This shows that NMR relaxometry can be considered as an alternative route of determining diffusion coefficients of both cations and anions in ionic liquids. PMID:24985656

  11. Determining diffusion coefficients of ionic liquids by means of field cycling nuclear magnetic resonance relaxometry

    NASA Astrophysics Data System (ADS)

    Kruk, D.; Meier, R.; Rachocki, A.; Korpała, A.; Singh, R. K.; Rössler, E. A.

    2014-06-01

    Field Cycling Nuclear Magnetic Resonance (FC NMR) relaxation studies are reported for three ionic liquids: 1-ethyl-3- methylimidazolium thiocyanate (EMIM-SCN, 220-258 K), 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM-BF4, 243-318 K), and 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6, 258-323 K). The dispersion of 1H spin-lattice relaxation rate R1(ω) is measured in the frequency range of 10 kHz-20 MHz, and the studies are complemented by 19F spin-lattice relaxation measurements on BMIM-PF6 in the corresponding frequency range. From the 1H relaxation results self-diffusion coefficients for the cation in EMIM-SCN, BMIM-BF4, and BMIM-PF6 are determined. This is done by performing an analysis considering all relevant intra- and intermolecular relaxation contributions to the 1H spin-lattice relaxation as well as by benefiting from the universal low-frequency dispersion law characteristic of Fickian diffusion which yields, at low frequencies, a linear dependence of R1 on square root of frequency. From the 19F relaxation both anion and cation diffusion coefficients are determined for BMIM-PF6. The diffusion coefficients obtained from FC NMR relaxometry are in good agreement with results reported from pulsed- field-gradient NMR. This shows that NMR relaxometry can be considered as an alternative route of determining diffusion coefficients of both cations and anions in ionic liquids.

  12. A monolithic functional film of nanotubes/cellulose/ionic liquid for high performance supercapacitors

    NASA Astrophysics Data System (ADS)

    Basiricò, Lucia; Lanzara, Giulia

    2014-12-01

    A novel monolithic, pre-fabricated, fully functional film made of a nanostructured free-standing layer is presented for a new and competitive class of easy-to-assemble flexible supercapacitors whose design is in-between the all solid state and the traditional liquid electrolyte. The film is made of two vertically aligned multi-walled carbon nanotube (VANT) electrodes that store ions, embedded-in, and monolithically interspaced by a solution of microcrystalline cellulose in a room temperature ionic liquid (RTIL) electrolyte (1-ethyl-3-methylimidazolium acetate-EMIM Ac). The fine tuning of VANTs length and electrolyte/cellulose amount leads, in a sole and continuous block, to ions storage and physical separation between the electrodes without the need of the additional separator layer that is typically used in supercapacitors. Thus, physical discontinuities that can induce disturbances to ions mobility, are fully eliminated significantly reducing the equivalent series resistance and increasing the knee frequency, hence outclassing the best supercapacitors based on VANTs and non-aqueous electrolytes. The excellent electrochemical response can also be addressed to the chosen electrolyte that, not only has the advantage of leading to a significantly simpler and more affordable fabrication procedure, but has higher ionic conductivity, lower viscosity and higher ions mobility than other electrolytes capable of dissolving cellulose.

  13. Predicting cellulose solvating capabilities of acid-base conjugate ionic liquids.

    PubMed

    Parviainen, Arno; King, Alistair W T; Mutikainen, Ilpo; Hummel, Michael; Selg, Christoph; Hauru, Lauri K J; Sixta, Herbert; Kilpeläinen, Ilkka

    2013-11-01

    Different acid-base conjugates were made by combining a range of bases and superbases with acetic and propionic acid. Only the combinations that contained superbases were capable of dissolving cellulose. Proton affinities were calculated for the bases. A range, within which cellulose dissolution occurred, when combined with acetic or propionic acid, was defined for further use. This was above a proton affinity value of about 240 kcal mol(-1) at the MP2/6-311+G(d,p)//MP2/ 6-311+G(d,p) ab initio level. Understanding dissolution allowed us to determine that cation acidity contributed considerably to the ability of ionic liquids to dissolve cellulose and not just the basicity of the anion. By XRD analyses of suitable crystals, hydrogen bonding interactions between anion and cation were found to be the dominant interactions in the crystalline state. From determination of viscosities of these conjugates over a temperature range, certain structures were found to have as low a viscosity as 1-ethyl-3-methylimidazolium acetate, which was reflected in their high rate of cellulose dissolution but not necessarily the quantitative solubility of cellulose in those ionic liquids. 1,5-Diazabicyclo[4.3.0]non-5-enium propionate, which is one of the best structures for cellulose dissolution, was then distilled using laboratory equipment to demonstrate its recyclability. PMID:24106149

  14. True molecular solutions of natural cellulose in the binary ionic liquid-containing solvent mixtures.

    PubMed

    Rein, Dmitry M; Khalfin, Rafail; Szekely, Noemi; Cohen, Yachin

    2014-11-01

    Evidence is presented for the first time of true molecular dissolution of cellulose in binary mixtures of common polar organic solvents with ionic liquid. Cryogenic transmission electron microscopy, small-angle neutron-, X-ray- and static light scattering were used to investigate the structure of cellulose solutions in mixture of dimethyl formamide and 1-ethyl-3-methylimidazolium acetate. Structural information on the dissolved chains (average molecular weight ∼ 5 × 10(4)g/mol; gyration radius ∼ 36 nm, persistence length ∼ 4.5 nm), indicate the absence of significant aggregation of the dissolved chains and the calculated value of the second virial coefficient ∼ 2.45 × 10(-2)mol ml/g(2) indicates that this solvent system is a good solvent for cellulose. More facile dissolution of cellulose could be achieved in solvent mixtures that exhibit the highest electrical conductivity. Highly concentrated cellulose solution in pure ionic liquid (27 wt.%) prepared according to novel method, utilizing the rapid evaporation of a volatile co-solvent in binary solvent mixtures at superheated conditions, shows insignificant cellulose molecular aggregation. PMID:25129726

  15. Structural features affecting the enzymatic digestibility of pine wood pretreated with ionic liquids.

    PubMed

    Torr, Kirk M; Love, Karen T; Simmons, Blake A; Hill, Stefan J

    2016-03-01

    Pretreating lignocellulosic biomass with certain ionic liquids results in structural and chemical changes that make the biomass more digestible by enzymes. In this study, pine wood was pretreated with 1-ethyl-3-methylimidazolium chloride/acetate ([C2 mim]Cl and [C2 mim][OAc]) at different temperatures to investigate the relative importance of substrate features, such as accessible surface area, cellulose crystallinity, and lignin content, on enzymatic digestibility. The ionic liquid pretreatments resulted in glucan conversions ranging from 23% to 84% on saccharification of the substrates, with [C2 mim][OAc] being more effective than [C2 mim]Cl. The pretreatments resulted in no delignification of the wood, some loss of cellulose crystallinity under certain conditions, and varying levels of increased surface area. Enzymatic digestibility closely correlated with accessible surface area and porosity measurements obtained using Simons' staining and thermoporosimetry techniques. Increased accessible surface area was identified as the principal structural feature responsible for the improved enzymatic digestibility. PMID:26369903

  16. Molecular dynamics investigation of the ionic liquid/enzyme interface: application to engineering enzyme surface charge.

    PubMed

    Burney, Patrick R; Nordwald, Erik M; Hickman, Katie; Kaar, Joel L; Pfaendtner, Jim

    2015-04-01

    Molecular simulations of the enzymes Candida rugosa lipase and Bos taurus α-chymotrypsin in aqueous ionic liquids 1-butyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazolium ethyl sulfate were used to study the change in enzyme-solvent interactions induced by modification of the enzyme surface charge. The enzymes were altered by randomly mutating lysine surface residues to glutamate, effectively decreasing the net surface charge by two for each mutation. These mutations resemble succinylation of the enzyme by chemical modification, which has been shown to enhance the stability of both enzymes in ILs. After establishing that the enzymes were stable on the simulated time scales, we focused the analysis on the organization of the ionic liquid substituents about the enzyme surface. Calculated solvent charge densities show that for both enzymes and in both solvents that changing positively charged residues to negative charge does indeed increase the charge density of the solvent near the enzyme surface. The radial distribution of IL constituents with respect to the enzyme reveals decreased interactions with the anion are prevalent in the modified systems when compared to the wild type, which is largely accompanied by an increase in cation contact. Additionally, the radial dependence of the charge density and ion distribution indicates that the effect of altering enzyme charge is confined to short range (≤1 nm) ordering of the IL. Ultimately, these results, which are consistent with that from prior experiments, provide molecular insight into the effect of enzyme surface charge on enzyme stability in ILs. PMID:25641162

  17. Cellulose Solubility in Ionic Liquid Mixtures: Temperature, Cosolvent, and Antisolvent Effects.

    PubMed

    Minnick, David L; Flores, Raul A; DeStefano, Matthew R; Scurto, Aaron M

    2016-08-18

    Select ionic liquids (ILs) dissolve significant quantities of cellulose through disruption and solvation of inter- and intramolecular hydrogen bonds. In this study, thermodynamic solid-liquid equilibrium was measured with microcrystalline cellulose in a model IL, 1-ethyl-3-methylimidazolium diethyl phosphate ([EMIm][DEP]) and mixtures with protic antisolvents and aprotic cosolvents between 40 and 120 °C. The solubility of cellulose in pure [EMIm][DEP] exhibits an asymptotic maximum of approximately 20 mass % above 100 °C. Solubility studies conducted on antisolvent mixtures with [EMIm][DEP] and [BMIm][Cl] indicate that protic solvents, ethanol, methanol, and water, significantly reduce the cellulose capacity of IL mixtures by 38-100% even at small antisolvent loadings (<5 mass %). Alternatively, IL-aprotic cosolvent (dimethyl sulfoxide, dimethylformamide, and 1,3-dimethyl-2-imidazolidinone) mixtures at mass ratios up to 1:1 enhance cellulose dissolution by 20-60% compared to pure [EMIm][DEP] at select temperatures. Interactions between the IL and molecular solvents were investigated by Kamlet-Taft solvatochromic analysis, FTIR, and NMR spectroscopy. The results indicate that preferential solvation of the IL cation and anion by co- and antisolvents impact the ability of IL ions to interact with cellulose thus affecting the cellulose dissolution capacity of IL-solvent mixtures. PMID:27447741

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

    PubMed Central

    Kan, Tetsuo; Aoki, Hironori; Binh-Khiem, Nguyen; Matsumoto, Kiyoshi; Shimoyama, Isao

    2013-01-01

    A temperature sensor that uses temperature-sensitive fluorescent dyes is developed. The droplet sensor has a diameter of 40 μm and uses 1 g/L of Rhodamine B (RhB) and 0.5 g/L of Rhodamine 110 (Rh110), which are fluorescent dyes that are dissolved in an ionic liquid (1-ethyl-3-methylimidazolium ethyl sulfate) to function as temperature indicators. This ionic liquid is encapsulated using vacuum Parylene film deposition (which is known as the Parylene-on-liquid-deposition (PoLD) method). The droplet is sealed by the chemically stable and impermeable Parylene film, which prevents the dye from interacting with the molecules in the solution and keeps the volume and concentration of the fluorescent material fixed. The two fluorescent dyes enable the temperature to be measured ratiometrically such that the droplet sensor can be used in various applications, such as the wireless temperature measurement of microregions. The sensor can measure the temperature of such microregions with an accuracy of 1.9 °C, a precision of 3.7 °C, and a fluorescence intensity change sensitivity of 1.0%/K. The sensor can measure temperatures at different sensor depths in water, ranging from 0 to 850 μm. The droplet sensor is fabricated using microelectromechanical system (MEMS) technology and is highly applicable to lab-on-a-chip devices. PMID:23535716

  19. Nonaborane and decaborane cluster anions can enhance the ignition delay in hypergolic ionic liquids and induce hypergolicity in molecular solvents.

    PubMed

    McCrary, Parker D; Barber, Patrick S; Kelley, Steven P; Rogers, Robin D

    2014-05-01

    The dissolution of nido-decaborane, B10H14, in ionic liquids that are hypergolic (fuels that spontaneously ignite upon contact with an appropriate oxidizer), 1-butyl-3-methylimidazolium dicyanamide, 1-methyl-4-amino-1,2,4-triazolium dicyanamide, and 1-allyl-3-methylimidazolium dicyanamide, led to the in situ generation of a nonaborane cluster anion, [B9H14](-), and reductions in ignition delays for the ionic liquids suggesting salts of borane anions could enhance hypergolic properties of ionic liquids. To explore these results, four salts based on [B10H13](-) and [B9H14](-), triethylammonium nido-decaborane, tetraethylammonium nido-decaborane, 1-ethyl-3-methylimidazolium arachno-nonaborane, and N-butyl-N-methyl-pyrrolidinium arachano-nonaborane were synthesized from nido-decaborane by reaction of triethylamine or tetraethylammonium hydroxide with nido-decaborane in the case of salts containing the decaborane anion or via metathesis reactions between sodium nonaborane (Na[B9H14]) and the corresponding organic chloride in the case of the salts containing the nonaborane anion. These borane cluster anion salts form stable solutions in some combustible polar aprotic solvents such as tetrahydrofuran and ethyl acetate and trigger hypergolic reactivity of these solutions. Solutions of these salts in polar protic solvents are not hypergolic. PMID:24716643

  20. A Green Synthesis of Nanosheet-Constructed Pd Particles in an Ionic Liquid and Their Superior Electrocatalytic Performance.

    PubMed

    Zhang, Baohua; Xue, Yiguo; Xue, Zhimin; Li, Zhonghao; Hao, Jingcheng

    2015-12-21

    The ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM]Ac) is investigated as a solvent for the synthesis of Pd particles. Interestingly, nanosheet-constructed Pd particles could be successfully synthesized in [EMIM]Ac without any additional reducing agent and template under ionothermal conditions. [EMIM]Ac itself works as the solvent, the reducing agent, and the template for the formation of these interesting Pd particles, making this method complementary to the well-known ionic-liquid-precursor approach. Furthermore, [EMIM]Ac can be recycled with no loss of activity for the formation of nanosheet-constructed Pd particles within our studied cycles. Specifically, the nanosheet-constructed Pd particles exhibit superior electrocatalytic activity and stability towards ethanol oxidation and formic acid oxidation compared with commercially available Pd black catalyst, thus demonstrating their promising applications in fuel-cell area. The current approach, thus, presents a green approach towards the synthesis of Pd particles, using only a simple palladium salt and an ionic liquid. PMID:26463254

  1. An Electrochemical NO2 Sensor Based on Ionic Liquid: Influence of the Morphology of the Polymer Electrolyte on Sensor Sensitivity

    PubMed Central

    Kuberský, Petr; Altšmíd, Jakub; Hamáček, Aleš; Nešpůrek, Stanislav; Zmeškal, Oldřich

    2015-01-01

    A systematic study was carried out to investigate the effect of ionic liquid in solid polymer electrolyte (SPE) and its layer morphology on the characteristics of an electrochemical amperometric nitrogen dioxide sensor. Five different ionic liquids were immobilized into a solid polymer electrolyte and key sensor parameters (sensitivity, response/recovery times, hysteresis and limit of detection) were characterized. The study revealed that the sensor based on 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][N(Tf)2]) showed the best sensitivity, fast response/recovery times, and low sensor response hysteresis. The working electrode, deposited from water-based carbon nanotube ink, was prepared by aerosol-jet printing technology. It was observed that the thermal treatment and crystallinity of poly(vinylidene fluoride) (PVDF) in the solid polymer electrolyte influenced the sensitivity. Picture analysis of the morphology of the SPE layer based on [EMIM][N(Tf)2] ionic liquid treated under different conditions suggests that the sensor sensitivity strongly depends on the fractal dimension of PVDF spherical objects in SPE. Their deformation, e.g., due to crowding, leads to a decrease in sensor sensitivity. PMID:26569248

  2. Phase Behavior and Ionic Conductivity of Concentrated Solutions of Polystyrene-Poly(ethylene oxide) Diblock Copolymers in an Ionic Liquid

    SciTech Connect

    Simone, Peter M.; Lodge, Timothy P.

    2010-03-16

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

  3. Taylor cones of ionic liquids from capillary tubes as sources of pure ions: The role of surface tension and electrical conductivity

    NASA Astrophysics Data System (ADS)

    Garoz, D.; Bueno, C.; Larriba, C.; Castro, S.; Romero-Sanz, I.; Fernandez de la Mora, J.; Yoshida, Y.; Saito, G.

    2007-09-01

    The emissions of Taylor cones from a wide range of ionic liquids (ILs) have been tested in vacuo in an attempt to identify what physical properties favor the purely ionic regime (PIR). This regime is well known in the case of Taylor cones of liquid metals. For nonmetallic liquids, it has been previously observed in conventional (capillary tube) electrospray sources at room temperature only for the room temperature molten salt (ionic liquid) EMI -BF4 (EMI =1-ethyl-3-methylimidazolium). A large number of other ILs and their mixtures have been studied here, most of which (but not all) are unable to reach the PIR at room temperature. Based on these results and additional theoretical considerations, strong support is assembled for the notion that the PIR is favored by ILs not only of high electrical conductivity but also of high surface tension. This hypothesis is confirmed by tests with three recently synthesized ILs, EMI -GaCl4, EMI -C(CN)3, and EMI -N(CN)2, all of which combine exceptional surface tension and electrical conductivity, and all of which reach the PIR at room temperature far more readily than EMI -BF4.

  4. Sputter-deposition of silver nanoparticles into ionic liquid as a sacrificial reservoir in antimicrobial organosilicate nanocomposite coatings.

    PubMed

    Hamm, Steven C; Shankaran, Ravi; Korampally, Venu; Bok, Sangho; Praharaj, Snigdha; Baker, Gary A; Robertson, J David; Lee, Byung Doo; Sengupta, Shramik; Gangopadhyay, Keshab; Gangopadhyay, Shubhra

    2012-01-01

    We present a new approach for fabricating robust, regenerable antimicrobial coatings containing an ionic liquid (IL) phase incorporating silver nanoparticles (AgNPs) as a reservoir for Ag(0)/Ag(+) species within sol-gel-derived nanocomposite films integrating organosilicate nanoparticles. The IL serves as an ultralow volatility (vacuum-compatible) liquid target, allowing for the direct deposition and dispersion of a high-density AgNP "ionosol" following conventional sputtering techniques. Two like-anion ILs were investigated in this work: methyltrioctylammonium bis(trifluoromethylsulfonyl)imide, [N(8881)][Tf(2)N], and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [emim][Tf(2)N]. Silver ionosols derived from these two ILs were incorporated into silica-based sol-gel films and the resultant antimicrobial activity evaluated against Pseudomonas aeruginosa bacteria. Imaging of the surface morphologies of the as-prepared films established a link between an open macroporous film architecture and the observation of high activity. Nanocomposites based on [N(8881)][Tf(2)N] displayed excellent antimicrobial activity against P. aeruginosa over multiple cycles, reducing cell viability by 6 log units within 4 h of contact. Surprisingly, similar films prepared from [emim][Tf(2)N] presented negligible antimicrobial activity, an observation we attribute to the differing abilities of these IL cations to infiltrate the cell wall, regulating the influx of silver ions to the bacterium's interior. PMID:22235768

  5. Screening out the non-Arrhenius behaviour of nematic-isotropic transition by room temperature ionic liquid.

    PubMed

    Dan, K; Datta, A; Yoshida, Y; Saito, G; Yoshikawa, K; Roy, M

    2016-02-28

    Differential Scanning Calorimetry (DSC) and optical polarization microscopy of a mixture of the liquid crystalline material (N-(4-methoxybenzylidene)-4-butylaniline, MBBA) and a Fe-based room temperature ionic liquid 1-ethyl-3-methylimidazolium tetrachloroferrate ([Emim](+) [FeCl4](-), EMIF) indicate a decrease in the nematic-isotropic (N-I) phase transition temperature (TNI) with an increase in EMIF concentration, explained by a proposed model of Coulomb "screening" of MBBA quadrupoles by the EMIF ions along with ionic "self screening." DSC studies of EMIF-MBBA and pure EMIF and comparison with pure MBBA results show that the major transitions in pure EMIF have Arrhenius behaviour, but more importantly the previously found convex Arrhenius behaviour of the pristine MBBA [K. Dan et al., Europhys. Lett. 108, 36007 (2014)] becomes Arrhenius in the mixture, indicating a conversion of the entropic N-I activation barrier to an enthalpic one. In presence of EMIF, a drastic decrease in the intensity of out-of-plane distortions of benzene rings in MBBA is found from Fourier transform infrared spectroscopy, consistent with significant reduction in the conformational states of MBBA. This suppression of large amplitude motion is again consistent with a Coulomb screening and gives a molecular basis for the entropic-to-enthalpic conversion of the N-I activation barrier. PMID:26931723

  6. Screening out the non-Arrhenius behaviour of nematic-isotropic transition by room temperature ionic liquid

    NASA Astrophysics Data System (ADS)

    Dan, K.; Datta, A.; Yoshida, Y.; Saito, G.; Yoshikawa, K.; Roy, M.

    2016-02-01

    Differential Scanning Calorimetry (DSC) and optical polarization microscopy of a mixture of the liquid crystalline material (N-(4-methoxybenzylidene)-4-butylaniline, MBBA) and a Fe-based room temperature ionic liquid 1-ethyl-3-methylimidazolium tetrachloroferrate ([Emim]+ [FeCl4]-, EMIF) indicate a decrease in the nematic-isotropic (N-I) phase transition temperature (TNI) with an increase in EMIF concentration, explained by a proposed model of Coulomb "screening" of MBBA quadrupoles by the EMIF ions along with ionic "self screening." DSC studies of EMIF-MBBA and pure EMIF and comparison with pure MBBA results show that the major transitions in pure EMIF have Arrhenius behaviour, but more importantly the previously found convex Arrhenius behaviour of the pristine MBBA [K. Dan et al., Europhys. Lett. 108, 36007 (2014)] becomes Arrhenius in the mixture, indicating a conversion of the entropic N-I activation barrier to an enthalpic one. In presence of EMIF, a drastic decrease in the intensity of out-of-plane distortions of benzene rings in MBBA is found from Fourier transform infrared spectroscopy, consistent with significant reduction in the conformational states of MBBA. This suppression of large amplitude motion is again consistent with a Coulomb screening and gives a molecular basis for the entropic-to-enthalpic conversion of the N-I activation barrier.

  7. Stable Deep Doping of Vapor-Phase Polymerized Poly(3,4-ethylenedioxythiophene)/Ionic Liquid Supercapacitors.

    PubMed

    Karlsson, Christoffer; Nicholas, James; Evans, Drew; Forsyth, Maria; Strømme, Maria; Sjödin, Martin; Howlett, Patrick C; Pozo-Gonzalo, Cristina

    2016-08-23

    Liquid-solution polymerization and vapor-phase polymerization (VPP) have been used to manufacture a series of chloride- and tosylate-doped poly(3,4-ethylenedioxythiophene) (PEDOT) carbon paper electrodes. The electrochemistry, specific capacitance, and specific charge were determined for single electrodes in 1-ethyl-3-methylimidazolium dicyanamide (emim dca) ionic liquid electrolyte. VPP-PEDOT exhibits outstanding properties with a specific capacitance higher than 300 F g(-1) , the highest value reported for a PEDOT-based conducting polymer, and doping levels as high as 0.7 charges per monomer were achieved. Furthermore, symmetric PEDOT supercapacitor cells with the emim dca electrolyte exhibited a high specific capacitance (76.4 F g(-1) ) and high specific energy (19.8 Wh kg(-1) ). A Ragone plot shows that the VPP-PEDOT cells combine the high specific power of conventional ("pure") capacitors with the high specific energy of batteries, a highly sought-after target for energy storage. PMID:27325487

  8. Effect of ionic liquid treatment on the structures of lignins in solutions

    SciTech Connect

    Cheng, Gang; Kent, Michael S; He, Lilin; Varanasi, Patanjali; Dibble, Dean; Melnichenko, Yuri B; Simmons, Blake; Singh, Seema

    2012-01-01

    The solution structures of three types of isolated lignin - organosolv (OS), Kraft (K), and low sulfonate (LS) - before and after treatment with 1-ethyl-3-methylimidazolium acetate were studied using small-angle neutron scattering (SANS) and dynamic light scattering (DLS) over a concentration range of 0.3-2.4 wt %. The results indicate that each of these lignins is comprised of aggregates of well-defined basal subunits, the shapes and sizes of which, in D{sub 2}O and DMSO-d{sub 6}, are revealed using these techniques. LS lignin contains a substantial amount of nanometer-scale individual subunits. In aqueous solution these subunits have a well-defined elongated shape described well by ellipsoidal and cylindrical models. At low concentration the subunits are highly expanded in alkaline solution, and the effect is screened with increasing concentration. OS lignin dissolved in DMSO was found to consist of a narrow distribution of aggregates with average radius 200 {+-} 30 nm. K lignin in DMSO consists of aggregates with a very broad size distribution. After ionic liquid (IL) treatment, LS lignin subunits in alkaline solution maintained the elongated shape but were reduced in size. IL treatment of OS and K lignins led to the release of nanometer-scale subunits with well-defined size and shape.

  9. Specific distributions of anions and cations of an ionic liquid through confinement between graphene sheets.

    PubMed

    Alibalazadeh, Mahtab; Foroutan, Masumeh

    2015-07-01

    This work was aimed to investigate the behavior, morphology, structure, and dynamical properties of pure ionic liquid (IL) 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4]) confined between two parallel and flat graphene sheets at different interwall distances, H. Thus, molecular dynamic (MD) simulations were performed for different interwall distances including (10, 14, 16, 20, 23, and 28) Å at seven temperatures from 278 to 308 K. These results showed that the distribution and orientation of cations and anions on the graphene sheets depended on H. At the shortest H, a dense monolayer of the anions and cations was formed between two graphene sheets. The number of these layers increased as H increased. The potential energy diagram as a function of H demonstrated a minimum potential energy at H = 16 Å. Also, there was a minimum overlap between the density profiles of the cations and anions at H = 16 Å. Diffusion coefficients of the cations and anions increased as temperature and H increased. Moreover, slope of the plot of the diffusion coefficients of the cations and anions versus H significantly changed at H = 16 Å. Orientation functions revealed that most of the cations oriented parallel to the graphene sheets. PMID:26048248

  10. A link between structure, diffusion and rotations of hydrogen bonding tracers in ionic liquids.

    PubMed

    Araque, Juan C; Daly, Ryan P; Margulis, Claudio J

    2016-05-28

    When solutes are small compared to the size of the ions in an ionic liquid, energetic heterogeneities associated with charge enhanced (stiff) and charge depleted (soft) nanoenvironments are sampled. In a recent article [J. C. Araque et al., J. Phys. Chem. B 119(23), 7015-7029 (2015)], we explored large deviations from Stokes-Einstein translational diffusion caused by such a heterogeneity. The current article is set to explore the effect of soft and stiff solvent environments (i.e., structure) on OH-bond rotations in the case of water and small alcohols in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (Im1,2 (+)NTf2 (-)). Is solute rotational dynamics heterogeneous? If so, are solute rotations and translations coupled in the sense that stiff and soft solvent environments hinder or speed up both types of dynamics? For the systems studied here, there appears to be a clear connection between translations, rotations, and stiff/soft solvent environments. We also discuss interesting asymmetries of the correlation between solutes with anions and cations. PMID:27250313

  11. Recovery of ionic liquid and sugars from hydrolyzed biomass using ion exclusion simulated moving bed chromatography.

    PubMed

    Mai, Ngoc Lan; Nguyen, Nam Trung; Kim, Jin-Il; Park, Hyuk-Min; Lee, Sung-Kyun; Koo, Yoon-Mo

    2012-03-01

    Efficient recovery of ionic liquid (IL) from aqueous mixture of ILs and sugars (which derived from enzymatic or chemical catalyzed hydrolysis of ILs-pretreated biomass) is a major drawback for commercialization of biofuel and platform chemicals production from biomass utilized ILs as pretreatment solvent. In this study, simulated moving bed (SMB) chromatography equipped with ion exclusion column (containing [Emim]+ cation) was investigated to separate sugars (glucose and xylose) which are the main products from biomass hydrolysate and 1-ethyl-3-methylimidazolium acetate (EmimAc) which is the ILs used for biomass pretreatment. A four-zone SMB system with a configuration of 2-2-2-2 (2 ion exclusion columns in each zone) was used to recover glucose, xylose and EmimAc from their aqueous mixture with yield of 71.38, 99.37 and 98.92%, respectively. Moreover, the optimization of SMB zone configuration by simulation results in a complete recovery of ILs. This result indicates that for the first time, ion exclusion SMB chromatography could be used for complete recovery of ILs from aqueous sugar mixture. PMID:22265172

  12. Phase diagram, solubility limit and hydrodynamic properties of cellulose in binary solvents with ionic liquid.

    PubMed

    Le, Kim Anh; Rudaz, Cyrielle; Budtova, Tatiana

    2014-05-25

    Cellulose solubility phase diagrams in two binary solvents based on 1-ethyl-3-methylimidazolium acetate (EmimAc) mixed with water and with dimethylsulfoxide (DMSO) were built. The minimal amount of EmimAc molecules needed to dissolve cellulose is 2.5-3moles per anhydroglucose unit. This proportion allows calculation of the maximal cellulose concentration soluble in EmimAc-DMSO at any composition; in EmimAc it is around 25-27wt%. Water forms hydrogen bonds with EmimAc and thus competes with cellulose for ionic liquid; the solubility of cellulose in EmimAc-water is much lower than that in EmimAc-DMSO. Hydrodynamic properties of cellulose in two solvent systems were compared. In EmimAc-DMSO cellulose intrinsic viscosity practically does not depend on DMSO content as predicted by the phase diagram. The intrinsic viscosity in EmimAc-water first increases with water content due to cellulose self-aggregation and then abruptly decreases due to coagulation. PMID:24708976

  13. Lignin dissolution in dialkylimidazolium-based ionic liquid-water mixtures.

    PubMed

    Wang, Yantao; Wei, Ligang; Li, Kunlan; Ma, Yingchong; Ma, Ningning; Ding, Shan; Wang, Linlin; Zhao, Deyang; Yan, Bing; Wan, Wenying; Zhang, Qian; Wang, Xin; Wang, Junmei; Li, Hui

    2014-10-01

    Lignin dissolution in dialkylimidazolium-based ionic liquid (IL)-water mixtures (40wt%-100wt% IL content) at 60°C was investigated. The IL content and type are found to considerably affect lignin solubility. For the IL-water mixtures except 1-butyl-3-methylimidazolium tetrafluoroborate ([C4C1im]BF4), the maximum lignin solubility can be achieved at 70wt% IL content. Lignin solubility in IL-water mixtures with different cations follows the order 1-butyl-3-methylimidazolium ([C4C1im](+))>1-hexyl-3-methylimidazolium ([C6C1im](+))>1-ethyl-3-methylimidazolium ([C2C1im](+))>1-octyl-3-methylimidazolium ([C8C1im](+))>1-butyl-3-ethylimidazolium ([C4C2im](+))>1-butyl-3-propylimidazolium ([C4C3im](+)). For IL mixtures with different anions, lignin solubility decreases in the following order: methanesulfonate (MeSO3(-))>acetate (MeCO2(-))>bromide (Br(-))>dibutylphosphate (DBP(-)). Evaluation using the theory of Hansen solubility parameter (HSP) is consistent with the experimental results, suggesting that HSP can aid in finding the appropriate range of IL content for IL-water mixtures. However, HSP cannot be used to evaluate the effect of IL type on lignin solubility. PMID:25164342

  14. Comparison of physical properties of regenerated cellulose films fabricated with different cellulose feedstocks in ionic liquid.

    PubMed

    Pang, JinHui; Wu, Miao; Zhang, QiaoHui; Tan, Xin; Xu, Feng; Zhang, XueMing; Sun, RunCang

    2015-05-01

    With the serious "white pollution" resulted from the non-biodegradable plastic films, considerable attention has been directed toward the development of renewable and biodegradable cellulose-based film materials as substitutes of petroleum-derived materials. In this study, environmentally friendly cellulose films were successfully prepared using different celluloses (pine, cotton, bamboo, MCC) as raw materials and ionic liquid 1-ethyl-3-methylimidazolium acetate as a solvent. The SEM and AFM indicated that all cellulose films displayed a homogeneous and smooth surface. In addition, the FT-IR and XRD analysis showed the transition from cellulose I to II was occurred after the dissolution and regeneration process. Furthermore, the cellulose films prepared by cotton linters and pine possessed the most excellent thermal stability and mechanical properties, which were suggested by the highest onset temperature (285°C) and tensile stress (120 MPa), respectively. Their excellent properties of regenerated cellulose films are promising for applications in food packaging and medical materials. PMID:25659673

  15. Scattering Studies on Poly(3,4-ethylenedioxythiophene)- Polystyrenesulfonate in the Presence of Ionic Liquids

    SciTech Connect

    Murphy, Ryan J.; Weigandt, Katie M.; Uhrig, David; Alsayed, Ahmed; Badre, Chantal; Hough, Larry; Muthukumar, Murugappan

    2015-11-30

    The demand for lower cost and flexible electronics has driven industry to develop alternative transparent electrode (TE) materials to replace indium tin oxide (ITO). ITO is the benchmark TE on the market, but its high cost and low flexibility limit it for use in future technologies. Recent work has shown the combination of the conducting polymer poly(3,4-ethylenedioxythiophene)–polystyrenesulfonate (PEDOT:PSS) with the ionic liquid 1-ethyl-3-methylimidazolium tetracyanoborate (EMIM:TCB) is a viable ITO replacement. This study investigates the nature of the interaction between PEDOT:PSS and EMIM:TCB in the solution state. A combination of scattering methods is used to illustrate a novel, multilength scale model of this system. At length scales larger than 300nm PEODT:PSS adopts a microgel-like structure, and below ~300nm the system adopts an entangled polyelectrolyte mesh structure. As EMIM:TCB is added, the microgel interior adopts a more neutral polymer mesh structure as EMIM:TCB concentration is increased.

  16. Crosslinking of polysaccharides in room temperature ionic liquids by ionizing radiation

    NASA Astrophysics Data System (ADS)

    Kimura, Atsushi; Nagasawa, Naotsugu; Shimada, Akihiko; Taguchi, Mitsumasa

    2016-07-01

    Crosslinking of polysaccharides in room temperature ionic liquids (RTILs) by ionizing radiation were investigated by the scavenging method, fluorescent and X-ray photoelectron spectroscopy (XPS) analysis. Radiation chemical yields of hydroxyl radicals inducing the crosslinking of cellulose were estimated with phenol as a scavenger, and increased with water content in 1-ethyl-3-methylimidazolium acetate (EMI-acetate). Cellulose gel was also produced in fluorescent carboxylate-based RTILs, 1,3-dibutylimidazolium acetate (DBI-acetate). Light emission from DBI-acetate in cellulose gel was observed and 20-nm red shifted at a maximum wavelength of 415 nm when excited at 323 nm. Expected elements of carbon and oxygen were detected in neat cellulose by XPS, while additional nitrogen was detected in radiation-crosslinked cellulose gel produced in EMI-acetate. These results indicate that RTILs is incorporated in the cellulose gel. Chitin gel was first obtained in 1-butyl-3-methyimidazolium chloride by γ-ray irradiations, and its gel fraction increased with the dose and reached 86% at 60 kGy.

  17. Structural and Electronic Properties of Amino Acid Based Ionic Liquids: A Theoretical Study

    NASA Astrophysics Data System (ADS)

    Wu, Yang; Zhang, Tiantian

    2009-10-01

    The gas-phase ion pairs of the ionic liquids containing 1-ethyl-3-methylimidazolium ([emim]+) and 20 natural amino acids ([AA]-) are studied at the B3LYP/6-311+G (d,p) level. The optimized structures, energies, and natural population analysis are presented and analyzed in terms of their possible correlation with the interaction energies and the H-bond separations. It is found that all the ion pairs of [emim][AA] can form strong H-bond interactions, which are dominated by the side-chain structure and the functional group of amino acid anions. The calculations indicate that an increase of the alkyl side-chain length coincides with a gradual decrease of H-bond energy, while the functional groups lead to the different localized charges on the anions, consequently affecting the electrostatic force. In addition, the intramolecular H bond in [AA]- can weaken the interaction, due to the decrease of the proton-accepting ability of the carbonyl O atoms. The H-bond chemical nature of [emim][AA] is investigated by atoms in molecules and natural bond orbital analyses. The preliminary analysis of 20 kinds of [emim][AA] ion pairs provides some initial hints as to the relationship between the interaction energy and the experimental glass transition temperature.

  18. Printable polymer actuators from ionic liquid, soluble polyimide, and ubiquitous carbon materials.

    PubMed

    Imaizumi, Satoru; Ohtsuki, Yuto; Yasuda, Tomohiro; Kokubo, Hisashi; Watanabe, Masayoshi

    2013-07-10

    We present here printable high-performance polymer actuators comprising ionic liquid (IL), soluble polyimide, and ubiquitous carbon materials. Polymer electrolytes with high ionic conductivity and reliable mechanical strength are required for high-performance polymer actuators. The developed polymer electrolytes comprised a soluble sulfonated polyimide (SPI) and IL, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([C2mim][NTf2]), and they exhibited acceptable ionic conductivity up to 1 × 10(-3) S cm(-1) and favorable mechanical properties (elastic modulus >1 × 10(7) Pa). Polymer actuators based on SPI/[C2mim][NTf2] electrolytes were prepared using inexpensive activated carbon (AC) together with highly electron-conducting carbon such as acetylene black (AB), vapor grown carbon fiber (VGCF), and Ketjen black (KB). The resulting polymer actuators have a trilaminar electric double-layer capacitor structure, consisting of a polymer electrolyte layer sandwiched between carbon electrode layers. Displacement, response speed, and durability of the actuators depended on the combination of carbons. Especially the actuators with mixed AC/KB carbon electrodes exhibited relatively large displacement and high-speed response, and they kept 80% of the initial displacement even after more than 5000 cycles. The generated force of the actuators correlated with the elastic modulus of SPI/[C2mim][NTf2] electrolytes. The displacement of the actuators was proportional to the accumulated electric charge in the electrodes, regardless of carbon materials, and agreed well with the previously proposed displacement model. PMID:23738653

  19. Effect of cation on diffusion coefficient of ionic liquids at onion-like carbon electrodes.

    PubMed

    Van Aken, Katherine L; McDonough, John K; Li, Song; Feng, Guang; Chathoth, Suresh M; Mamontov, Eugene; Fulvio, Pasquale F; Cummings, Peter T; Dai, Sheng; Gogotsi, Yury

    2014-07-16

    While most supercapacitors are limited in their performance by the stability of the electrolyte, using neat ionic liquids (ILs) as the electrolyte can expand the voltage window and temperature range of operation. In this study, ILs with bis(trifluoromethylsulfonyl)imide (Tf2N) as the anion were investigated as the electrolyte in onion-like carbon-based electrochemical capacitors. To probe the influence of cations on the electrochemical performance of supercapacitors, three different cations were used: 1-ethyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium and 1,6-bis(3-methylimidazolium-1-yl). A series of electrochemical characterization tests was performed using cyclic voltammetry (CV), galvanostatic cycling and electrochemical impedance spectroscopy (EIS). Diffusion coefficients were measured using EIS and correlated with quasielastic neutron scattering and molecular dynamics simulation. These three techniques were used in parallel to confirm a consistent trend between the three ILs. It was found that the IL with the smaller sized cation had a larger diffusion coefficient, leading to a higher capacitance at faster charge-discharge rates. Furthermore, the IL electrolyte performance was correlated with increasing temperature, which limited the voltage stability window and led to the formation of a solid electrolyte interphase on the carbon electrode surface, evident in both the CV and EIS experiments. PMID:24920163

  20. Scattering Studies on Poly(3,4-ethylenedioxythiophene)- Polystyrenesulfonate in the Presence of Ionic Liquids

    DOE PAGESBeta

    Murphy, Ryan J.; Weigandt, Katie M.; Uhrig, David; Alsayed, Ahmed; Badre, Chantal; Hough, Larry; Muthukumar, Murugappan

    2015-11-30

    The demand for lower cost and flexible electronics has driven industry to develop alternative transparent electrode (TE) materials to replace indium tin oxide (ITO). ITO is the benchmark TE on the market, but its high cost and low flexibility limit it for use in future technologies. Recent work has shown the combination of the conducting polymer poly(3,4-ethylenedioxythiophene)–polystyrenesulfonate (PEDOT:PSS) with the ionic liquid 1-ethyl-3-methylimidazolium tetracyanoborate (EMIM:TCB) is a viable ITO replacement. This study investigates the nature of the interaction between PEDOT:PSS and EMIM:TCB in the solution state. A combination of scattering methods is used to illustrate a novel, multilength scale modelmore » of this system. At length scales larger than 300nm PEODT:PSS adopts a microgel-like structure, and below ~300nm the system adopts an entangled polyelectrolyte mesh structure. As EMIM:TCB is added, the microgel interior adopts a more neutral polymer mesh structure as EMIM:TCB concentration is increased.« less

  1. Antibacterial and Antifungal Activity of Biopolymers Modified with Ionic Liquid and Laponite.

    PubMed

    Sharma, Anshu; Prakash, Prem; Rawat, Kamla; Solanki, Pratima R; Bohidar, H B

    2015-09-01

    In the present study, the antimicrobial properties of modified biopolymers such as gelatin and agar have been investigated. These biopolymers (agar and gelatin) are modified by dissolving in ionic liquid (IL) [1-ethyl-3-methylimidazolium chloride ([C2mim][Cl]) and 1-octyl-3-methyl imidazolium chloride ([C8mim][Cl])] solutions. It was noticed that agar-ionogel (Ag-IL), gelatin-ionogel (GB-IL), and gelatin organogel (gelatin-glycerol solution along with laponite, nanoclay) nanocomposite (GA-NC) formed are highly stable, optically clear, and transparent without any air bubbles. The antimicrobial activity of these (Ag-IL), (GB-IL), and GA-NC were analyzed for both gram-negative (Escherichia coli, Klebsiella pneumoniae) and gram-positive bacterial strains (Staphylococcus aureus and Staphylococcus pyogenes) and fungus A. niger, C. albicans. Antibacterial and antifungal activity studies were carried out at different dilutions such as 100, 99, and 90 % (v/v). It was found that Ag-IL, GB-IL, and individual IL ([C8mim][Cl]) exhibited superior antimicrobial activities, indicating that longer IL chain enhance the cell membrane permeability of S. aureus, S. pyogenes, and E. coli cells. However, GA-NC nanocomposite and [C2mim][Cl]-based composites does not exhibit any bacterial inhibition activity for all bacterial strains. PMID:26142901

  2. A link between structure, diffusion and rotations of hydrogen bonding tracers in ionic liquids

    NASA Astrophysics Data System (ADS)

    Araque, Juan C.; Daly, Ryan P.; Margulis, Claudio J.

    2016-05-01

    When solutes are small compared to the size of the ions in an ionic liquid, energetic heterogeneities associated with charge enhanced (stiff) and charge depleted (soft) nanoenvironments are sampled. In a recent article [J. C. Araque et al., J. Phys. Chem. B 119(23), 7015-7029 (2015)], we explored large deviations from Stokes-Einstein translational diffusion caused by such a heterogeneity. The current article is set to explore the effect of soft and stiff solvent environments (i.e., structure) on OH-bond rotations in the case of water and small alcohols in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([" separators="Im1,2 + ][" separators="NTf2- ]). Is solute rotational dynamics heterogeneous? If so, are solute rotations and translations coupled in the sense that stiff and soft solvent environments hinder or speed up both types of dynamics? For the systems studied here, there appears to be a clear connection between translations, rotations, and stiff/soft solvent environments. We also discuss interesting asymmetries of the correlation between solutes with anions and cations.

  3. Morphology, Modulus, and Ionic Conductivity of a Triblock Terpolymer/Ionic Liquid Electrolyte Membrane

    NASA Astrophysics Data System (ADS)

    McIntosh, Lucas D.; Lodge, Timothy P.

    2013-03-01

    A key challenge in designing solid polymer electrolytes is increasing bulk mechanical properties such as stiffness, without sacrificing ionic conductivity. Previous work has focused on diblock copolymers, where one block is a stiff, glassy insulator and the other is a flexible ion conductor. Disadvantages of these systems include difficulty in achieving network morphologies, which minimize dead-ends for ion transport, and the necessity to operate below both the Tg of the glassy block and the order-disorder temperature. We have investigated the triblock terpolymer poly[isoprene-b-(styrene-co-norbornenylethyl styrene)-b-ethylene oxide] because it self-assembles into a triply-continuous network structure. SAXS and TEM revealed the bulk morphology of INSO to be disordered but strongly correlated after solvent casting from dichloromethane. This apparent disordered network structure was retained after chemical crosslinking and addition of the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide. Impedance spectroscopy confirmed the expected conductivity for ions confined to continuous PEO channels. The mechanical response before and after crosslinking showed an increase in the material modulus.

  4. Microbundles of zinc oxide nanorods: Assembly in ionic liquid [EMIM]{sup +}[BF{sub 4}]{sup -}, photoluminescence and photocatalytic properties

    SciTech Connect

    Wang Li; Xu Shenzhi; Li Huijun; Chang Lixian; Zhisu; Zeng Minghua; Wang Lina; Huang Yineng

    2011-03-15

    A simple, efficient and low-temperature approach for the assembly of hierarchical Zinc oxide (ZnO) microstructures in ionic liquid [EMIM]{sup +}[BF{sub 4}]{sup -} is reported. The as-obtained ZnO superstructures are composed of microbundles of nanorods from the center points, with the diameter and length in the range of 100-150 nm and 2-4 {mu}m, which have been characterized by X-ray diffraction, scanning and transmission electron microscopy, and photoluminescence spectroscopy. The ZnO microstructures exhibit significant defect-related green-yellow emission and high photodegradation of dye Methyl Orange (5x10{sup -5} mol/L) under UV excitation within 80 min. -- Graphical abstract: Easy formation of microbundles of ZnO nanorods were accomplished in low temperature with [EMIM]{sup +}[BF{sub 4}]{sup -} (1-ethyl-3-methylimidazolium tetrafluoroborate) ionic liquid, which exhibit significant green-yellow photoluminescence property and high photodegradation of Methyl Orange dye. Display Omitted Research highlights: {yields} Ionic liquid assisted solid-state route was introduced into synthesis of ZnO nanorods. {yields} The distinctive microbundles ZnO nanorod assembles was evidenced by SEM and TEM. {yields} ZnO nano-material exhibited high efficiency in photodegradation of Methyl Orange.

  5. Ionic-liquid-assisted microwave distillation coupled with headspace single-drop microextraction followed by GC-MS for the rapid analysis of essential oil in Dryopteris fragrans.

    PubMed

    Jiao, Jiao; Gai, Qing-Yan; Wang, Wei; Luo, Meng; Zhao, Chun-Jian; Fu, Yu-Jie; Ma, Wei

    2013-12-01

    A rapid, green and effective miniaturized sample preparation technique, ionic-liquid-assisted microwave distillation coupled with headspace single-drop microextraction was developed for the extraction of essential oil from dried Dryopteris fragrans. 1-Ethyl-3-methylimidazolium acetate was the optimal ionic liquid as the destruction agent of plant cell walls and microwave absorption was medium. n-Heptadecane (2.0 μL) was adopted as the suspended microdrop solvent in the headspace for the extraction and concentration of essential oil. The optimal parameters of the proposed method were an irradiation power of 300 W, sample mass of 0.9 g, mass ratio of ionic liquids to sample of 2.8, extraction temperature of 79°C, and extraction time of 3.6 min. In comparison to the previous reports, the proposed technique could equally monitor all the essential oil components with no significant differences in a simple way, which was more rapid and required a much lower amount of sample. PMID:24174124

  6. A novel ionic liquid-in-oil microemulsion composed of biologically acceptable components: an excitation wavelength dependent fluorescence resonance energy transfer study.

    PubMed

    Mandal, Sarthak; Ghosh, Surajit; Banerjee, Chiranjib; Kuchlyan, Jagannath; Banik, Debasis; Sarkar, Nilmoni

    2013-03-21

    In this work we have reported the formulation of a novel ionic liquid-in-oil (IL/O) microemulsion where the polar core of the ionic liquid, 1-ethyl-3-methylimidazolium n-butylsulfate ([C2mim][C4SO4]), is stabilized by a mixture of two nontoxic nonionic surfactants, polyoxyethylene sorbitan monooleate (Tween-80) and sorbitan laurate (Span-20), in a biological oil phase of isopropyl myristate (IPM). The formation of the microemulsion droplets has been confirmed from the dynamic light scattering (DLS) and phase behavior study. To assess the dynamic heterogeneity of this tween-based IL/O microemulsion, we have performed an excitation wavelength dependent fluorescence resonance energy transfer (FRET) from coumarin 480 (C480) to rhodamine 6G (R6G). The multiple donor-acceptor (D-A) distances, ∼15, 30, and 45 Å, obtained from the rise times of the acceptor emission in the presence of a donor can be rationalized from the varying distribution of the donor, C480, in the different regions of the microemulsion system. With increasing the excitation wavelength from 375 to 408 nm, the contribution of the rise component of ∼240 ps which results the D-A distance of ∼30 Å increases significantly due to the enhanced contribution of the C480 probe molecules closer to the acceptor in the ionic liquid pool of the microemulsion. PMID:23445434

  7. Fluoroquinolone antibiotic determination in bovine, ovine and caprine milk using solid-phase extraction and high-performance liquid chromatography-fluorescence detection with ionic liquids as mobile phase additives.

    PubMed

    Herrera-Herrera, Antonio V; Hernández-Borges, Javier; Rodríguez-Delgado, Miguel Angel

    2009-10-23

    This paper describes the use of 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIm-BF(4)) as mobile phase additive for the analysis by high-performance liquid chromatography with fluorescence detection of a group of seven basic fluoroquinolone antibiotics (i.e. fleroxacin, ciprofloxacin, lomefloxacin, danofloxacin, enrofloxacin, sarafloxacin and difloxacin) in different milk samples. EMIm-BF(4) was found superior to 1-butyl-3-methylimidazolium tetrafluoroborate for the separation of the analytes from chromatographic interferences of the sample matrix. The optimized method was applied to the analysis of ovine, caprine and bovine milk, in the last case in either skimmed, semi-skimmed and full-cream milk after suitable acidic deproteination followed by a solid-phase extraction procedure. Recovery values between 73% and 113% were obtained for the three types of bovine milk samples, as well as for ovine and caprine milk (RSDs below 16% in all cases), which clearly demonstrates the applicability of the method to the three types of milk irrespective of the fat content of the samples. Limits of detection were in the range of 0.5-8.1 microg/L (approximately 0.5-25.9 microg/kg), well below the maximum residue limits established for these compounds by the current European legislation. A screening study of 24 different milk samples was also developed. In none of the samples, residues of the selected antibiotics were found. PMID:19268960

  8. Rapid analysis of Fructus forsythiae essential oil by ionic liquids-assisted microwave distillation coupled with headspace single-drop microextraction followed by gas chromatography-mass spectrometry.

    PubMed

    Jiao, Jiao; Ma, Dan-Hui; Gai, Qing-Yan; Wang, Wei; Luo, Meng; Fu, Yu-Jie; Ma, Wei

    2013-12-01

    A rapid, green and effective miniaturized sample preparation and analytical technique, i.e. ionic liquids-assisted microwave distillation coupled with headspace single-drop microextraction (ILAMD-HS-SDME) followed by gas chromatography-mass spectrometry (GC-MS) was developed for the analysis of essential oil (EO) in Fructus forsythiae. In this work, ionic liquids (ILs) were not only used as the absorption medium of microwave irradiation but also as the destruction agent of plant cell walls. 1-Ethyl-3-methylimidazolium acetate ([C2mim]OAc) was chosen as the optimal ILs. Moreover, n-heptadecane (2.0 μL) was selected as the appropriate suspended solvent for the extraction and concentration of EO. Extraction conditions of the proposed method were optimized using the relative peak area of EO constituents as the index, and the optimal operational parameters were obtained as follows: irradiation power (300 W), sample mass (0.7 g), mass ratio of ILs to sample (2.4), temperature (78°C) and time (3.4 min). In comparison to previous reports, the proposed method was faster and required smaller sample amount but could equally monitor all EO constituents with no significant differences. PMID:24267075

  9. Design of an electrolyte composition for stable and rapid charging-discharging of a graphite negative electrode in a bis(fluorosulfonyl)imide-based ionic liquid

    NASA Astrophysics Data System (ADS)

    Matsui, Yukiko; Yamagata, Masaki; Murakami, Satoshi; Saito, Yasuteru; Higashizaki, Tetsuya; Ishiko, Eriko; Kono, Michiyuki; Ishikawa, Masashi

    2015-04-01

    We evaluate the effects of lithium salt on the charge-discharge performance of a graphite negative electrode in 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMImFSI) ionic liquid-based electrolytes. Although the graphite negative electrode exhibits good cyclability and rate capability in both 0.43 mol dm-3 LiFSI/EMImFSI and LiTFSI/EMImFSI (TFSI- = bis(trifluoromethylsulfonyl)imide) at room temperature, only the LiFSI/EMImFSI system enables the graphite electrode to be operated with sufficient discharge capacity at the low temperature of 0 °C, even though there is no noticeable difference in ionic conductivity, compared with LiTFSI/EMImFSI. Furthermore, a clear difference in the low-temperature behaviors of the two cells composed of EMImFSI with a high-concentration of lithium salts is observed. Additionally, charge-discharge operation of the graphite electrode at C-rate of over 5.0 can be achieved using of the high-concentration LiFSI/EMImFSI electrolyte. Considering the low-temperature characteristics in both high-concentration electrolytes, the stable and rapid charge-discharge operation in the high-concentration LiFSI/EMImFSI is presumably attributed to a suitable electrode/electrolyte interface with low resistivity. These results suggest that optimization of the electrolyte composition can realize safe and high-performance lithium-ion batteries that utilize ionic liquid-based electrolytes.

  10. Interaction of ionic liquids with noble metal surfaces: structure formation and stability of [OMIM][TFSA] and [EMIM][TFSA] on Au(111) and Ag(111).

    PubMed

    Uhl, Benedikt; Huang, Hsinhui; Alwast, Dorothea; Buchner, Florian; Behm, R Jürgen

    2015-10-01

    Aiming at a comprehensive understanding of the interaction of ionic liquids (ILs) with metal surfaces we have investigated the adsorption of two closely related ILs, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [EMIM][TFSA] and 1-methyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide [OMIM][TFSA], with two noble metal surfaces, Au(111) and Ag(111), under ultrahigh vacuum (UHV) conditions using scanning tunneling microscopy (STM). At room temperature, the ILs form a 2D liquid on either of the two surfaces, while at lower temperatures they condense into two-dimensional (2D) islands which exhibit ordered structures or a short-range ordered 2D glass structure. Comparison of the adlayer structures formed in the different adsorption systems and also with those determined recently for n-butyl-n-methylpyrrolidinium [TFSA](-) adlayers on Ag(111) and Au(111) (B. Uhl et al., Beilstein J. Nanotechnol., 2013, 4, 903) gains detailed insight into the adsorption geometry of the IL ions on the surface. The close similarity of the adlayer structures indicates that (i) the structure formation is dominated by the tendency to optimize the anion adsorption geometry, and that (ii) also in the present systems the cation adsorbs with the alkyl chain pointing up from the surface. PMID:26305417

  11. Charging and aggregation of latex particles in aqueous solutions of ionic liquids: towards an extended Hofmeister series.

    PubMed

    Oncsik, Tamas; Desert, Anthony; Trefalt, Gregor; Borkovec, Michal; Szilagyi, Istvan

    2016-03-01

    The effect of ionic liquid (IL) constituents and other monovalent salts on the stability of polystyrene latex particles was studied by electrophoresis and light scattering in dilute aqueous suspensions. The surface charge and the aggregation rate were both sensitive to the type of ion leading to different critical coagulation concentration (CCC) values. Systematic variation of the type of IL cation and anion allows us to place these ions within the Hofmeister series. We find that the dicyanoamide anion should be placed between iodide and thiocyanate, while all 1-alkyl-3-methylimidazolium cations can be positioned to the left of the tetramethylammonium and ammonium ions. The hydrophobicity of the 1-butyl-1-methylpyrrolidinium (BMPL(+)) ion is intermediate between 1-ethyl-3-methylimidazolium (EMIM(+)) and 1-butyl-3-methylimidazolium (BMIM(+)). With increasing alkyl chain length, the 1-alkyl-3-methylimidazolium cations adsorb on the latex particles very strongly, and 1-hexyl-3-methylimidazolium (HMIM(+)) and 1-octyl-3-methylimidazolium (OMIM(+)) lead to pronounced charge reversal and to an intermediate restabilization region. PMID:26902948

  12. Influence of surfactant-free ionic liquid microemulsions pretreatment on the composition, structure and enzymatic hydrolysis of water hyacinth.

    PubMed

    Xu, Fan; Chen, Li; Wang, Aili; Yan, Zongcheng

    2016-05-01

    This study investigated the pretreatment performance of surfactant-free ionic liquid microemulsions (ILMs) on water hyacinth. Pretreatment effects were evaluated in terms of lignocellulosic composition, structure and enzymatic hydrolysis. Analysis of the regenerated water hyacinth indicated that the content of the lignocellulosic composition changed, and the surface became more porous. After being pretreated with ILM(a) (mass ratio of toluene: ethanol: 1-ethyl-3-methylimidazolium acetate ([Emim]Ac)=0.35:0.3:0.35) at 70°C for 12h, the maximum delignification of 63.6% was observed. The cellulose of the water hyacinth was well protected and retained during the pretreatment process. After being enzymatically hydrolyzed for 48 h, the reducing sugar yield of the water hyacinth pretreated with ILM(a) at 70°C for 6 h was 563.7 mg/g, and its hydrolysis yield (86.1%) was nearly four and a half times of that of the untreated one (20.2%). In conclusion, the designed surfactant-free ILMs exhibit promising potential application in biomass pretreatment. PMID:26913644

  13. Simultaneous saccharification and fermentation of cellulose in ionic liquid for efficient production of α-ketoglutaric acid by Yarrowia lipolytica.

    PubMed

    Ryu, Seunghyun; Labbé, Nicole; Trinh, Cong T

    2015-05-01

    Ionic liquids (ILs) are benign solvents that are highly effective for biomass pretreatment. However, their applications for scale-up biorefinery are limited due to multiple expensive IL recovery and separation steps that are required. To overcome this limitation, it is very critical to develop a compatible enzymatic and microbial biocatalyst system to carry the simultaneous saccharification and fermentation in IL environments (SSF-IL). While enzymatic biocatalysts have been demonstrated to be compatible with various IL environments, it is challenging to develop microbial biocatalysts that can thrive and perform efficient biotransformation under the same conditions (pH and temperature). In this study, we harnessed the robust metabolism of Yarrowia lipolytica as a microbial platform highly compatible with the IL environments such as 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]). We optimized the enzymatic and microbial biocatalyst system using commercial cellulases and demonstrated the capability of Y. lipolytica to convert cellulose into high-value organics such as α-ketoglutaric acid (KGA) in the SSF-IL process at relatively low temperature 28 °C and high pH 6.3. We showed that SSF-IL not only enhanced the enzymatic saccharification but also produced KGA up to 92% of the maximum theoretical yield. PMID:25783627

  14. Saccharification and ethanol fermentation from cholinium ionic liquid-pretreated bagasse with a different number of post-pretreatment washings.

    PubMed

    Ninomiya, Kazuaki; Omote, Sayuri; Ogino, Chiaki; Kuroda, Kosuke; Noguchi, Mana; Endo, Takatsugu; Kakuchi, Ryohei; Shimizu, Nobuaki; Takahashi, Kenji

    2015-01-01

    Choline acetate (ChOAc), a cholinium ionic liquid (IL), was compared with 1-ethyl-3-methylimidazolium acetate (EmimOAc) with regard to biomass pretreatment, inhibition on cellulase and yeast, residuals in pretreated biomass, and saccharification and fermentation of pretreated biomass. Irrespective of ChOAc and EmimOAc, cellulose and hemicellulose saccharification of the IL-pretreated bagasse were over 90% and 60%, respectively. Median effective concentrations (EC50) based on cellulase activity were 32 wt% and 16 wt% for ChOAc and EmimOAc, respectively. The EC50 based on yeast growth were 3.1 wt% and 0.3 wt% for ChOAc and EmimOAc respectively. The residuals in IL-pretreated bagasse were 10% and 23% for ChOAc and EmimOAc, respectively, when washed 2 times after pretreatment. Ethanol yield on a bagasse basis were 60% and 24% for ChOAc and EmimOAc, respectively, in the saccharification and fermentation of IL-pretreated bagasse when washed 2 times. ChOAc-pretreated bagasse could be saccharified and fermented with fewer wash times than EmimOAc-pretreated bagasse. PMID:25898080

  15. An abnormal N-heterocyclic carbene-carbon dioxide adduct from imidazolium acetate ionic liquids: the importance of basicity.

    PubMed

    Kelemen, Zsolt; Péter-Szabó, Barbara; Székely, Edit; Hollóczki, Oldamur; Firaha, Dzmitry S; Kirchner, Barbara; Nagy, József; Nyulászi, László

    2014-09-26

    In the reaction of 1-ethyl-3-methylimidazolium acetate [C2C1Im][OAc] ionic liquid with carbon dioxide at 125 °C and 10 MPa, not only the known N-heterocyclic carbene (NHC)-CO2 adduct I, but also isomeric aNHC-CO2 adducts II and III were obtained. The abnormal NHC-CO2 adducts are stabilized by the presence of the polarizing basic acetate anion, according to static DFT calculations and ab initio molecular dynamics studies. A further possible reaction pathway is facilitated by the high basicity of the system, deprotonating the initially formed NHC-CO2 adduct I, which can then be converted in the presence of the excess of CO2 to the more stable 2-deprotonated anionic abnormal NHC-CO2 adduct via the anionic imidazolium-2,4-dicarboxylate according to DFT calculations on model compounds. This suggests a generalizable pathway to abnormal NHC complex formation. PMID:25137312

  16. Molecular interactions in the ionic liquid emim acetate and water binary mixtures probed via NMR spin relaxation and exchange spectroscopy.

    PubMed

    Allen, Jesse J; Bowser, Sage R; Damodaran, Krishnan

    2014-05-01

    Interactions of ionic liquids (ILs) with water are of great interest for many potential IL applications. 1-Ethyl-3-methylimidazolium (emim) acetate, in particular, has shown interesting interactions with water including hydrogen bonding and even chemical exchange. Previous studies have shown the unusual behavior of emim acetate when in the presence of 0.43 mole fraction of water, and a combination of NMR techniques is used herein to investigate the emim acetate-water system and the unusual behavior at 0.43 mole fraction of water. NMR relaxometry techniques are used to describe the effects of water on the molecular motion and interactions of emim acetate with water. A discontinuity is seen in nuclear relaxation behavior at the concentration of 0.43 mole fraction of water, and this is attributed to the formation of a hydrogen bonded network. EXSY measurements are used to determine the exchange rates between the H2 emim proton and water, which show a complex dependence on the concentration of the mixture. The findings support and expand our previous results, which suggested the presence of an extended hydrogen bonding network in the emim acetate-water system at concentrations close to 0.50 mole fraction of H2O. PMID:24654003

  17. Using confocal Raman microscopy to real-time monitor poplar cell wall swelling and dissolution during ionic liquid pretreatment.

    PubMed

    Zhang, Xun; Ma, Jing; Ji, Zhe; Yang, Gui-Hua; Zhou, Xia; Xu, Feng

    2014-08-01

    The ionic liquids (ILs) are recognized as the potential solvents for the pretreatment of lignocellulosic materials before biomass conversion. However, little knowledge of how the cell wall of biomass responds to the IL locally and dynamically during the pretreatment is available. In the current work, the process of IL pretreatment of poplar using 1-ethyl-3-methylimidazolium acetate ([C2 mim][OAc]) was real-time monitored on a cellular level by employing confocal Raman microscopy. The results showed that the biomass dissolution during the IL pretreatment can be clearly divided into two stages: (1) slow penetration of IL, and (2) rapid dissolution of lignin and carbohydrates. In this case, the onset of the dissolution of these compositions occurred only after the cell wall of biomass swelled to a certain extent. Because the first stage was a slow process which determined the process reaction rate, it can be deduced that enhancing the penetration capacity of IL was crucial for improving the pretreatment efficiency. Based on the obtained results, a model was proposed to better understand how the plant cell wall responds to the IL before, during, and after pretreatment. PMID:24861030

  18. Critical regime for the insulator-metal transition in highly ordered conjugated polymers gated with ionic liquid

    NASA Astrophysics Data System (ADS)

    Ito, Hiroshi; Harada, Tomonori; Tanaka, Hisaaki; Kuroda, Shin-ichi

    2016-03-01

    We report the room-temperature and low-temperature transport properties of a poly(2,5-bis(3-hexadecylthiophene-2-yl)thieno[3,2-b]thiophene) (PBTTT) film gated with an ionic liquid based on 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide at different annealing temperatures of the PBTTT film. By annealing the film up to 235 °C and subsequently cooling it, we observed a ribbonlike structure, as reported. For the 235-°C-annealed (ribbon phase) film, we could apply a higher voltage without any decrease in the channel conductivity than for the 180-°C-annealed (terrace phase) film. As a result, a charge mobility as high as 10 cm2 V-1 s-1 was achieved for the ribbon-phase film. The power-law behavior of the temperature dependence of the electrical conductivity at low temperatures, indicating the critical regime for the insulator-metal transition, was observed. The ribbon-phase film exhibits an even weaker temperature dependence with a smaller exponent of β = 0.10 than the terrace-phase film.

  19. Balance between the physical diffusion and the exchange reaction on binary ionic liquid electrolyte for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Hao, Feng; Lin, Hong; Zhang, Jing; Li, Jianbao

    A comprehensive characterizations of viscosities, conductivities, triiodide diffusion coefficients, charge-transfer resistances and photovoltaic performance of a potential dye-sensitized solar cell (DSC) electrolyte systems based on binary ionic liquid (IL) mixtures, namely, 1-ethyl-3-methylimidazolium dicyanamide (EMIDCA)/1-methyl-3-propylimidazolium iodide (PMII) with a fixed iodine concentration at varying EMIDCA volume fraction are investigated in the present study. Viscosity and conductivity values are accurately correlated with regard to temperature and EMIDCA volume fraction. The triiodide diffusion coefficients, the predominant electrolyte parameter for limitation of DSC efficiency, are determined by symmetrical cell methods. The physical diffusion and exchange reactions between the iodide and triiodide dominate the apparent triiodide diffusion coefficients at different range of EMIDCA volume fraction. A balance between the viscosity-dependent physical diffusion and the exchange reactions can get at an optimal volume percents of EMIDCA. Impedance spectroscopy and photovoltaic results both support the existence of an optimized binary IL electrolyte composition. Hence, for optimizing an IL-based electrolyte in regards to triiodide transport, a low viscosity is not the exclusive crucial factor since exchange reactions transport effects also play an important role to resolve the diffusion limitation of DSC efficiency.

  20. Separation of 1,3-substituted imidazoles for quality control of a Lewis acidic ionic liquid for aluminum electroplating.

    PubMed

    Kosmus, Patrick; Steiner, Oliver; Goessler, Walter; Gollas, Bernhard

    2014-05-01

    Ionic liquids (ILs) are already used or have great potential in many industrial applications. Knowledge about their unique physicochemical characteristics makes ILs suitable for the electrodeposition of metals with very low negative potentials. Aluminum with its good corrosion protection behavior has great capability to be electroplated from IL electrolytes on steel substrates. The stability of the chosen electrolyte is very important to ensure industrial applicability. In this study, temperature and electrochemical long-term stability from electrolytes based on a Lewis acidic mixture of AlCl3 and 1-ethyl-3-methylimidazolium chloride are investigated. A published method was modified to identify possible degradation products using mass spectrometric detection. The optimized method used an Agilent Zorbax SB-Phenyl column (2.0 × 150 mm, 5 μm particles) with a 20 mmol TFA and 5% ACN mobile phase. This method allowed the quantification of several imidazoles from 0.1 to 100 mg/L. When analyzing the long-term stressed electrolytes, no significant changes in electrolyte composition could be observed. PMID:24254472

  1. Synthesis of alloy AuCu nanoparticles with the L1₀ structure in an ionic liquid using sputter deposition.

    PubMed

    Suzuki, Shushi; Tomita, Yousuke; Kuwabata, Susumu; Torimoto, Tsukasa

    2015-03-01

    Sputter deposition onto ionic liquids (ILs) was applied to synthesize AuCu bimetallic alloy nanoparticles (NPs) dispersed in 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI-BF4). A mixed target of Au and Cu materials was used for simultaneous sputter deposition onto the IL under an Ar pressure of 10 Pa. Two types of heating procedures within the range of 323-573 K were examined for control of the structures of NPs, particularly addressing the phase transition of the alloy NPs from the face centered cubic (fcc) structure to the L1₀ structure. One was heating after the sputter deposition in N2 at atmospheric pressure for 1 h. Another was a combination of heating during the sputter deposition and subsequent heating under an Ar pressure from 0.5 to 0.8 Pa for 1 h. Although both cases exhibited lowering of the phase transition temperatures compared with the temperature for the bulk, the latter procedure at 423 K only provided the NPs (approx. 5 nm) consisting of the L1₀ structure in the dispersed manner. A mechanism for forming the L1₀ structure was proposed for explaining the difference between results obtained using the two procedures. PMID:25623552

  2. Stable iron carbide nanoparticle dispersions in [Emim][SCN] and [Emim][N(CN)2] ionic liquids.

    PubMed

    Khare, Varsha; Kraupner, Alexander; Mantion, Alexandre; Jelicić, Aleksandra; Thünemann, Andreas F; Giordano, Cristina; Taubert, Andreas

    2010-07-01

    Dispersions of Fe(3)C nanoparticles in several ionic liquids (ILs) have been investigated. The ILs are based on 1-ethyl-3-methylimidazolium [Emim] and 1-butyl-3-methylimidazolium [Bmim] cations. Anions are ethylsulfate [ES], methanesulfonate [MS], trifluoromethylsulfonate (triflate) [TfO], tetrafluoroborate [BF(4)], dicyanamide [N(CN)(2)], and thiocyanate [SCN]. Among the ILs studied, [Emim][SCN] and [Emim][N(CN)(2)] stand out because only in these ILs have stable and transparent nanoparticle dispersions been obtained. All other ILs lead to blackish, slightly turbid dispersions or to completely nontransparent suspensions, which often contain undispersed sediment. UV/vis spectroscopy, transmission electron microscopy, and X-ray scattering suggest that the reason for the stabilization of the Fe(3)C nanoparticles in [Emim][SCN] is the leaching of traces of iron from the particles (without affecting the crystal structure of the Fe(3)C particles). The resulting particle surface is thus carbon-rich, which presumably favors the stabilization of the particles. A similar explanation can be postulated for [Emim][N(CN)(2)], with the dicyanamide anion also being a good ligand for iron. PMID:20426431

  3. Ion-cage interpretation for the structural and dynamic changes of ionic liquids under an external electric field.

    PubMed

    Shi, Rui; Wang, Yanting

    2013-05-01

    In many applications, ionic liquids (ILs) work in a nonequilibrium steady state driven by an external electric field. However, how the electric field changes the structure and dynamics of ILs and its underlying mechanism still remain poorly understood. In this paper, coarse-grained molecular dynamics simulations were performed to investigate the structure and dynamics of 1-ethyl-3-methylimidazolium nitrate ([EMIm][NO3]) under a static electric field. The ion cage structure was found to play an essential role in determining the structural and dynamic properties of the IL system. With a weak or moderate electric field (0-10(7) V/m), the external electric field is too weak to modify the ion cage structure in an influential way and thus the changes of structural and dynamic properties are negligible. With a strong electric field (10(7)-10(9) V/m) applied, ion cages expand and deform apparently, leading to the increase of ion mobility and self-diffusion coefficient with electric field, and the self-diffusion of ions along the electric field becomes faster than the other two directions due to the anisotropic deformation of ion cages. In addition, the Einstein relation connecting diffusion and mobility breaks down at strong electric fields, and it also breaks down for a single ion species even at moderate electric fields (linear-response region). PMID:23557150

  4. Engineering the electrochemical capacitive properties of graphene sheets in ionic-liquid electrolytes by correct selection of anions.

    PubMed

    Shi, Minjie; Kou, Shengzhong; Yan, Xingbin

    2014-11-01

    Graphene sheet (GS)-ionic liquid (IL) supercapacitors are receiving intense interest because their specific energy density far exceeds that of GS-aqueous electrolytes supercapacitors. The electrochemical properties of ILs mainly depend on their diverse ions, especially anions. Therefore, identifying suitable IL electrolytes for GSs is currently one of the most important tasks. The electrochemical behavior of GSs in a series of ILs composed of 1-ethyl-3-methylimidazolium cation (EMIM(+)) with different anions is systematically studied. Combined with the formula derivation and building models, it is shown that the viscosity, ion size, and molecular weight of ILs affect the electrical conductivity of ILs, and thus, determine the electrochemical performances of GSs. Because the EMIM-dicyanamide IL has the lowest viscosity, ion size, and molecular weight, GSs in it exhibit the highest specific capacitance, smallest resistance, and best rate capability. In addition, because the tetrafluoroborate anion (BF4(-)) has the best electrochemical stability, the GS-[EMIM][BF4] supercapacitor has the widest potential window, and thus, displays the largest energy density. These results may provide valuable information for selecting appropriate ILs and designing high-performance GS-IL supercapacitors to meet different needs. PMID:25146489

  5. 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.

    PubMed

    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. PMID:26654730

  6. Ionic liquids as potential carriers of low viscosity magnetorheological fluids

    NASA Astrophysics Data System (ADS)

    Guerrero-Sanchez, Carlos; Ortiz-Alvarado, Armando; Schubert, Ulrich S.

    2009-03-01

    Based on the latest investigations on the formulation of new magneto-rheological fluids, it is envisioned that the use of ionic liquids as carriers of magneto-rheological fluids will open new possibilities of applications for these smart fluids due to the fact that their physical and chemical properties can be fine-tuned in a broad range. This contribution addresses one potentially important advantage of magneto-rheological fluids which use ionic liquids as novel carriers. In connection with this, magneto-rheological fluids with a low viscosity in the off-state without compromising other properties of the formulations (e. g., sedimentation of the dispersed magnetic particles, liquid state of the carriers in a broad range of temperatures) are often required for specific applications. In this regard, ionic liquids of low viscosity can be very useful in the development of such magneto-rheological fluids. Thus, this contribution reports on the magnetorheological properties of iron(II, III) oxide particles dispersed in the ionic liquid 1-ethyl-3-methylimidazolium thiocyanate (a low viscosity ionic liquid) in the temperature range from 20 °C to 80 °C. The experimental results have revealed that the apparent viscosity of the dispersion slightly changes with the temperature when a constant magnetic field is applied and its value mainly depends on the shear rate and the strength of the magnetic field. The viscosity of the dispersion remains practically unmodified with both the temperature and the magnetic field intensity as the magnetic saturation of the material is reached; in this regime the viscosity will only depend on the applied shear rate. In contrast, the yield stress values of the dispersion as well as the corresponding shear stress vs. shear rate curves have shown an inverse behavior with temperature for a constant magnetic field.

  7. Viscosity Measurements on Ionic Liquids: A Cautionary Tale

    NASA Astrophysics Data System (ADS)

    Diogo, João C. F.; Caetano, Fernando J. P.; Fareleira, João M. N. A.; Wakeham, William A.

    2014-10-01

    The vibrating-wire viscometer has proven to be an exceedingly effective means of determining the viscosity of liquids over a wide range of temperature and pressure. The instrument has a long history but a variety of technological and theoretical developments over a number of years have improved its precision and most recently have enabled absolute measurements of high accuracy. However, the nature of the electrical measurements required for the technique has inhibited its widespread use for electrically conducting liquids so that there have been only a limited number of measurements. In the particular context of ionic liquids, which have themselves attracted considerable attention, this is unfortunate because it has meant that one primary measurement technique has seldom been employed for studies of their viscosity. In the last 2 years systematic efforts have been made to explore the applicability of the vibrating-wire technique by examining a number of liquids of increasing electrical conductivity. These extensions have been successful. However, in the process we have had cause to review previous studies of the viscosity and density of the same liquids at moderate temperatures and pressures and significant evidence has been accumulated to cause concern about the application of a range of viscometric techniques to these particular fluids. Because the situation is reminiscent of that encountered for a new set of environmentally friendly refrigerants at the end of the last decade, in this paper the experimental methods employed with these liquids have been reviewed which leads to recommendations for the handling of these materials that may have consequences beyond viscometric measurements. In the process new viscosity and density data for 1-hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide [mim][], 1-ethyl-3-methylimidazolium ethyl sulfate [mim][], and 1-ethyl-3-methylpyridinium ethyl sulfate [mpy][] have been obtained.

  8. Thermoelectric Potential of Polymer-Scaffolded Ionic Liquid Membranes

    NASA Astrophysics Data System (ADS)

    Datta, R. S.; Said, S. M.; Sahamir, S. R.; Karim, M. R.; Sabri, M. F. M.; Nakajo, T.; Kubouchi, M.; Hayashi, K.; Miyazaki, Y.

    2014-06-01

    Organic thin films have been viewed as potential thermoelectric (TE) materials, given their ease of fabrication, flexibility, cost effectiveness, and low thermal conductivity. However, their intrinsically low electrical conductivity is a main drawback which results in a relatively lower TE figure of merit for polymer-based TE materials than for inorganic materials. In this paper, a technique to enhance the ion transport properties of polymers through the introduction of ionic liquids is presented. The polymer is in the form of a nanofiber scaffold produced using the electrospinning technique. These fibers were then soaked in different ionic liquids based on substituted imidazolium such as 1-ethyl-3-methylimidazolium chloride or 1-butyl-3-methylimidazolium bromide. This method was applied to electrospun polyacrylonitrile and a mixture of polyvinyl alcohol and chitosan polymers. The ion transport properties of the membranes have been observed to increase with increasing concentration of ionic liquid, with maximum electrical conductivity of 1.20 × 10-1 S/cm measured at room temperature. Interestingly, the maximum electrical conductivity value surpassed the value of pure ionic liquids. These results indicate that it is possible to significantly improve the electrical conductivity of a polymer membrane through a simple and cost-effective method. This may in turn boost the TE figures of merit of polymer materials, which are well known to be considerably lower than those of inorganic materials. Results in terms of the Seebeck coefficient of the membranes are also presented in this paper to provide an overall representation of the TE potential of the polymer-scaffolded ionic liquid membranes.

  9. Enhanced Photocatalytic Reduction of CO2 to CO through TiO2 Passivation of InP in Ionic Liquids.

    PubMed

    Zeng, Guangtong; Qiu, Jing; Hou, Bingya; Shi, Haotian; Lin, Yongjing; Hettick, Mark; Javey, Ali; Cronin, Stephen B

    2015-09-21

    A robust and reliable method for improving the photocatalytic performance of InP, which is one of the best known materials for solar photoconversion (i.e., solar cells). In this article, we report substantial improvements (up to 18×) in the photocatalytic yields for CO2 reduction to CO through the surface passivation of InP with TiO2 deposited by atomic layer deposition (ALD). Here, the main mechanisms of enhancement are the introduction of catalytically active sites and the formation of a pn-junction. Photoelectrochemical reactions were carried out in a nonaqueous solution consisting of ionic liquid, 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM]BF4), dissolved in acetonitrile, which enables CO2 reduction with a Faradaic efficiency of 99% at an underpotential of +0.78 V. While the photocatalytic yield increases with the addition of the TiO2 layer, a corresponding drop in the photoluminescence intensity indicates the presence of catalytically active sites, which cause an increase in the electron-hole pair recombination rate. NMR spectra show that the [EMIM](+) ions in solution form an intermediate complex with CO2(-), thus lowering the energy barrier of this reaction. PMID:26224665

  10. Synthesis and Characterisation of ETS-10/Acetate-based Ionic Liquid/Chitosan Mixed Matrix Membranes for CO2/N2 Permeation

    PubMed Central

    Casado-Coterillo, Clara; López-Guerrero, María del Mar; Irabien, Ángel

    2014-01-01

    Mixed matrix membranes (MMMs) were prepared by incorporating organic surfactant-free hydrothermally synthesised ETS-10 and 1-ethyl-3-methylimidazolium acetate ionic liquid (IL) to chitosan (CS) polymer matrix. The membrane material characteristics and permselectivity performance of the two-component membranes were compared with the three-component membrane and the pure CS membrane. The addition of IL increased CO2 solubility of the polymer, and, thus, the CO2 affinity was maintained for the MMMs, which can be correlated with the crystallinity, measured by FT-IR, and void fraction calculations from differences between theoretical and experimental densities. The mechanical resistance was enhanced by the ETS-10 nanoparticles, and flexibility decreased in the two-component ETS-10/CS MMMs, but the flexibility imparted by the IL remained in three-component ETS-10/IL/CS MMMs. The results of this work provide insight into another way of facing the adhesion challenge in MMMs and obtain CO2 selective MMMs from renewable or green chemistry materials. PMID:24957178