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Sample records for 1-ethyl-3-methylimidazolium tetrafluorobroate emibf4

  1. Structural analysis of 1-ethyl-3-methylimidazolium bifluoride melt

    Science.gov (United States)

    Matsumoto, Kazuhiko; Hagiwara, Rika; Ito, Yasuhiko; Kohara, Shinji; Suzuya, Kentaro

    2003-01-01

    The structure of 1-ethyl-3-methylimidazolium bifluoride (EMImF · HF) melt has been analyzed at 333 K by a high-energy synchrotron X-ray diffraction method. The total correlation function of the EMImF · HF melt was similar to that of the solid state, indicating that not only the short range but also the intermediate-range ordering in the solid are partially preserved in the liquid state. The intra-molecular F-F correlation in the anions clearly appears in the total correlation function of the EMImF · HF melt, whereas prominent peaks are not observed in the case of a room temperature molten salt, 1-ethyl-3-methylimidazolium fluorohydrogenate.

  2. Structural analysis of 1-ethyl-3-methylimidazolium bifluoride melt

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Kazuhiko; Hagiwara, Rika. E-mail: hagiwara@energy.kyoto-u.ac.jp; Ito, Yasuhiko; Kohara, Shinji; Suzuya, Kentaro

    2003-01-01

    The structure of 1-ethyl-3-methylimidazolium bifluoride (EMImF {center_dot} HF) melt has been analyzed at 333 K by a high-energy synchrotron X-ray diffraction method. The total correlation function of the EMImF {center_dot} HF melt was similar to that of the solid state, indicating that not only the short range but also the intermediate-range ordering in the solid are partially preserved in the liquid state. The intra-molecular F-F correlation in the anions clearly appears in the total correlation function of the EMImF {center_dot} HF melt, whereas prominent peaks are not observed in the case of a room temperature molten salt, 1-ethyl-3-methylimidazolium fluorohydrogenate.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Electrochemistry of tin in the 1-ethyl-3-methylimidazolium dicyanamide room temperature ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Leong, Tin-Iao; Hsieh, Yi-Ting [Department of Chemistry, National Cheng Kung University, Tainan, Taiwan (China); Sun, I-Wen, E-mail: iwsun@mail.ncku.edu.t [Department of Chemistry, National Cheng Kung University, Tainan, Taiwan (China)

    2011-04-15

    Research highlights: {yields} The electrochemistry of Sn(II) was studied in the room temperature ionic liquid 1-ethyl-3-methylimidazolium dicyanamide (EMI-DCA) on a glassy carbon (GC) and a polycrystalline Pt electrode at 40 {sup o}C. {yields} The Sn(II) species was introduced into the ionic liquid by either dissolution of SnCl{sub 2} or anodizing a Sn wire. {yields} The reduction potential of the Sn(II)/Sn couple produced in these two solutions was found to be different, indicating that different Sn(II) species may be present. {yields} The diffusion coefficient of SnCl{sub 2} dissolved in the EMI-DCA was in the same order of magnitude as those reported for SnCl{sub 2} in several other ionic liquids. {yields} Depending on the deposition potentials, potentiostatic electrolysis produced Sn deposits with various unusual morphologies such as hexagonal tubes, spiral nanowires, and dendrite. - Abstract: The electrochemistry of Sn(II) was studied in the room temperature ionic liquid 1-ethyl-3-methylimidazolium dicyanamide (EMI-DCA) on a glassy carbon (GC) and a polycrystalline Pt electrode at 40 {sup o}C. The Sn(II) species was introduced into the ionic liquid by either dissolution of SnCl{sub 2} or anodizing a Sn wire. The reduction potential of the Sn(II)/Sn couple produced in these two solutions was found to be different, indicating that different Sn(II) species may be present. The order of the reduction potential of the two Sn(II) species indicates that the Gutmann donor ability of the anions is likely to be DCA{sup -} > Cl{sup -}. Cyclic voltammetry indicates the stripping efficiency is >90% on the Pt but only 40% on the GC electrode. Analysis of the chronoamperometric transient behavior during electrodeposition suggests that the deposition of Sn on the GC electrode involves a three dimensional progressive nucleation on a finite number of active sites. The diffusion coefficient of SnCl{sub 2} dissolved in the EMI-DCA was found to be 9.8 x 10{sup -7} cm{sup 2} s

  5. Impact of ionic liquid pretreatment conditions on cellulose crystalline structure using 1-ethyl-3-methylimidazolium acetate.

    Science.gov (United States)

    Cheng, Gang; Varanasi, Patanjali; Arora, Rohit; Stavila, Vitalie; Simmons, Blake A; Kent, Michael S; Singh, Seema

    2012-08-23

    Ionic liquids (ILs) have been shown to affect cellulose crystalline structure in lignocellulosic biomass during pretreatment. A systematic investigation of the swelling and dissolution processes associated with IL pretreatment is needed to better understand cellulose structural transformation. In this work, 3-20 wt % microcrystalline cellulose (Avicel) solutions were treated with 1-ethyl-3-methylimidazolium acetate ([C(2)mim][OAc]) and a mixture of [C(2)mim][OAc] with the nonsolvent dimethyl sulfoxide (DMSO) at different temperatures. The dissolution process was slowed by decreasing the temperature and increasing cellulose loading, and was further retarded by addition of DMSO, enabling in-depth examination of the intermediate stages of dissolution. Results show that the cellulose I lattice expands and distorts prior to full dissolution in [C(2)mim][OAc] and that upon precipitation the former structure leads to a less ordered intermediate structure, whereas fully dissolved cellulose leads to a mixture of cellulose II and amorphous cellulose. Enzymatic hydrolysis was more rapid for the intermediate structure (crystallinity = 0.34) than for cellulose II (crystallinity = 0.54).

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

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

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

    Science.gov (United States)

    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.

  8. 1-Ethyl-3-methylimidazolium acetate as a highly efficient organocatalyst for cyanosilylation of carbonyl compounds with trimethylsilyl cyanide

    Science.gov (United States)

    Ullah, Bakhtar; Chen, Jingwen; Zhang, Zhiguo; Xing, Huabin; Yang, Qiwei; Bao, Zongbi; Ren, Qilong

    2017-01-01

    1-Ethyl-3-methylimidazolium acetate is introduced as a robust organocatalyst for solvent-free cyanosilylation of carbonyl compounds with trimethylsilyl cyanide (TMSCN). The catalyst loading can be reduced to as low as 0.1–0.0001 mol % under mild reaction conditions, giving considerably high TOF values from 10,843 h−1 to 10,602,410 h−1 in the field of organocatalyzed transformations. The present protocol not only tolerates with extensive carbonyl compounds but also provides somewhat insight into the mechanism of ionic liquids (ILs)-catalyzed reactions. PMID:28198462

  9. Studies on electrical double layer capacitor with a low-viscosity ionic liquid 1-ethyl-3-methylimidazolium tetracyanoborate as electrolyte

    Indian Academy of Sciences (India)

    G P Pandey; S A Hashmi

    2013-08-01

    The performance of an electrical double layer capacitor (EDLC) composed of high surface area activated carbon electrodes and a new ionic liquid, 1-ethyl-3-methylimidazolium tetracyanoborate, [EMIm]TCB, as the electrolyte has been investigated by impedance spectroscopy, cyclic voltammetry and galvanostatic charge–discharge studies. The high ionic conductivity (∼1.3 × 10-2 S cm-1 at 20 °C) and low viscosity (∼22 cP) of the ionic liquid, [EMIm]TCB, make it attractive as electrolyte for its use in EDLCs. The optimum capacitance value of 195.5 F g-1 of activated carbon has been achieved with stable cyclic performance.

  10. Structural characteristics of 1-ethyl-3-methylimidazolium bifluoride: HF-deficient form of a highly conductive room temperature molten salt

    Science.gov (United States)

    Matsumoto, Kazuhiko; Tsuda, Tetsuya; Hagiwara, Rika; Ito, Yasuhiko; Tamada, Osamu

    2002-01-01

    EMIF·HF, 1-ethyl-3-methylimidazolium bifluoride, has been obtained by eliminating HF from a room temperature molten salt EMIF·2.3HF at around 400 K. EMIF·HF crystallizes in space group P2 1/m with a=7.281(1) Å, b=6.762(1) Å, c=8.403(1) Å, β=107.26(1)°, V=395.09(18) Å 3, Z=2 at room temperature. The cations are stacked in pillars via the hydrogen bonding between the C4 proton and the ring π-electrons of the adjacent cation. The cations and the anions coupled by strong hydrogen bondings are co-planar.

  11. Investigation of Ternary Mixtures Containing 1-Ethyl-3-methylimidazolium Bis(trifluoromethanesulfonylazanide, Ethylene Carbonate and Lithium Bis(trifluoromethanesulfonylazanide

    Directory of Open Access Journals (Sweden)

    Andreas Hofmann

    2016-05-01

    Full Text Available Temperature-dependent viscosity, conductivity and density data of ternary mixtures containing 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonylazanide (EMIM-TFSA, ethylene carbonate (EC, and lithium bis(trifluoromethanesulfonylazanide (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.

  12. The Preparation of Cellulose/Collagen Composite Films using 1-Ethyl-3-Methylimidazolium Acetate as a Solvent

    Directory of Open Access Journals (Sweden)

    Min Zhang

    2013-12-01

    Full Text Available Cellulose/collagen composite films with weight ratios of 30/1 (Blend-1 and 10/1 (Blend-2 were prepared using 1-ethyl-3-methylimidazolium acetate as a common solvent. The morphology of the films observed with a field-emission scanning electron microscope displayed a dependence on the ratio of cellulose/collagen. Collagen was successfully composited with cellulose without degradation and showed a denaturation temperature (Td higher than that of native collagen. Fourier transform infrared spectroscopy suggested that there were hydrogen-bond interactions between collagen and cellulose in the regenerated composite films. Thermogravimetric analysis revealed that the maximum decomposition temperature (Tmax of cellulose decreased after regeneration, while the Tmax of Blend-1 increased; however, it was reduced again for Blend-2. Elastic moduli from dynamic mechanical analysis exhibited a trend similar to that of Tmax. As indicated by X-ray diffraction, the distance between cellulose molecular chains was shortened for Blend-1 and elongated for Blend-2. Furthermore, the crystallization indices were calculated to be 75.3%, 68.3%, 66.2%, and 55.4% for native cellulose, regenerated films of cellulose, Blend-1, and Blend-2, respectively. These results confirm the dependence of the structural properties of composite films on cellulose/collagen ratios through the interactions between cellulose and collagen.

  13. Electrochemical performance of microporous and mesoporous activated carbons in neat and diluted 1-ethyl-3-methylimidazolium tetrafluoroborate

    Science.gov (United States)

    Kumagai, Seiji; Hatomi, Masaki; Tashima, Daisuke

    2017-03-01

    1-Ethyl-3-methylimidazolium tetrafluoroborate (EMIm·BF4), neat and diluted with propylene carbonate to 1 mol L-1, have been employed as electrolytes of electrical double-layer capacitors (EDLCs). The effects of microporosity and mesoporosity in activated carbon (AC) electrodes on the capacitive and resistive performances upon the use of neat and diluted EMIm·BF4 have been explored. In addition to cyclic voltammetry and galvanostatic charge-discharge tests, electrochemical impedance spectroscopy has been performed employing Kang's equivalent circuit model consisting of three resistances, three constant phase elements, and one bounded Warburg impedance. The overall impedance of the EDLC cell was separated into components of intrinsic resistance, bulk electrolyte, diffusion layer, and Helmholtz layer. The specific capacitance and the equivalent series resistance (ESR) of mesoporous AC were found to be highly dependent on the rate of ionic transfer. Lower cell voltage was identified as being responsible for lower specific capacitance and larger ESR of mesoporous AC, which was similarly seen in the neat and diluted EMIm·BF4, and could be alleviated by increasing the cell voltage. The inferior rate performance and the cell-voltage-dependent performance of mesoporous AC, which were more distinctly observed in the neat EMIm·BF4, could be attributed to the lower mobility of EMIm+ and BF4- in mesopores.

  14. Isobaric (vapor + liquid) equilibria of 1-ethyl-3-methylimidazolium ethylsulfate plus (propionaldehyde or valeraldehyde): Experimental data and prediction

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Victor H. [School of Chemical Engineering, University of Campinas (UNICAMP), Av. Albert Einstein 500, 13083-852 Campinas, SP (Brazil); Mattedi, Silvana [Chemical Engineering Department, Polytechnic School, Federal University of Bahia (UFBA), R. Aristides Novis 2, 40210-630 Salvador, BA (Brazil); Aznar, Martin, E-mail: maznar@feq.unicamp.b [School of Chemical Engineering, University of Campinas (UNICAMP), Av. Albert Einstein 500, 13083-852 Campinas, SP (Brazil)

    2011-06-15

    Research highlights: We report density, refraction index, and VLE for (propionaldehyde or valeraldehyde) + [emim][EtSO{sub 4}]. The Peng-Robinson + Wong-Sandler + COSMO-SAC model was used to predict density and VLE. The densities were predicted with deviations below than 2.3%. The experimental VLE was predicted with deviations below than 1.6%. - Abstract: This paper reports the density, refraction index, and (vapor + liquid) equilibria (VLE) for binary systems {l_brace}aldehyde + 1-ethyl-3-methylimidazolium ethylsulfate ([emim][EtSO{sub 4}]){r_brace}: {l_brace}propionaldehyde + [emim][EtSO{sub 4}]{r_brace} and {l_brace}valeraldehyde + [emim][EtSO{sub 4}]{r_brace}. The uncertainties for the temperature, pressure, and compositions measurements for the phase equilibria are {+-}0.1 K, {+-}0.01 kPa and {+-}0.0004, respectively. A qualitative analysis of the variation of the properties with changes in solvent and temperature was performed. The Peng-Robinson equation of state (PR EoS), coupled with the Wong-Sandler mixing rule (WS), is used to describe the experimental data. To calculate activity coefficients we used three different models: NRTL, UNIQUAC, and COSMO-SAC. Since the predictive liquid activity coefficient model COSMO-SAC is used in the Wong-Sandler mixing rule, the resulting thermodynamic model is a completely predictive one. The prediction results for the density and for the (vapor + liquid) equilibria have a deviation lower than 2.3% and 1.6%, respectively. The (vapor + liquid) equilibria predictions show a good description for the propionaldehyde system and only a qualitative description for the valeraldehyde system.

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

    Science.gov (United States)

    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.

  16. The effects of a co-solvent on fabrication of cellulose acetate membranes from solutions in 1-ethyl-3-methylimidazolium acetate

    KAUST Repository

    Kim, Dooli

    2016-08-15

    Ionic liquids have been considered green solvents for membrane fabrication. However, the high viscosity of their polymer solutions hinders the formation of membranes with strong mechanical properties. In this study, acetone was explored as a co-solvent with the ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) to dissolve cellulose acetate. The effects of acetone on the thermodynamic and kinetic aspects of the polymer solutions were studied and the physicochemical properties and separation capability of their resultant membranes were analyzed. The Hansen solubility parameters of [EMIM]OAc were measured by the software HSPiP and these data demonstrated that acetone was a suitable co-solvent to increase the solubility of cellulose acetate. The Gibbs free energy of mixing ΔGm was estimated to determine the proper composition of the polymer solution with better solubility. The study of the kinetics of phase separation showed that the demixing rate of the CA polymer solution in acetone and [EMIM]OAc was higher than that for solutions in [EMIM]OAc only. The membranes prepared from the former solution had higher water permeance and better mechanical stability than those prepared from the later solution. Adding acetone as a co-solvent opened the opportunity of fabricating membranes with higher polymer concentrations for higher separation capability and better mechanical properties. © 2016

  17. Phase Behaviour of 1-Ethyl-3-methylimidazolium Thiocyanate Ionic Liquid with Catalytic Deactivated Compounds and Water at Several Temperatures: Experiments and Theoretical Predictions

    Directory of Open Access Journals (Sweden)

    Ramalingam Anantharaj

    2011-01-01

    Full Text Available Density, surface tension and refractive index were determined for the binary mixture of catalytic deactivated compounds with 1-ethyl-3-methylimidazolium thiocyanate {[EMIM][SCN]} at temperature of (298.15 to 323.15 K. For all the compounds with ILs, the densities varied linearly in the entire mole fraction with increasing temperature. From the obtained data, the excess molar volume and deviation of surface tension and refractive index have been calculated. A strong interaction was found between similar (cation-thiophene or cation-pyrrole compounds. The interaction of IL with dissimilar compounds such as indoline and quinoline and other multiple ring compounds was found to strongly depend on the composition of IL at any temperatures. For the mixtures, the surface tension decreases in the order of: thiophene > quinoline > pyridine > indoline > pyrrole > water. In general from the excess volume studies, the IL-sulphur/nitrogen mixture has stronger interaction as compared to IL-IL, thiophene-thiophene or pyrrole-pyrrole interaction. The deviation of surface tension was found to be inversely proportional to deviation of refractive index. The quantum chemical based COSMO-RS was used to predict the non-ideal liquid phase activity coefficient for all mixtures. It indicated an inverse relation between activity coefficient and excess molar volumes.

  18. Stability and kinetic behavior of immobilized laccase from Myceliophthora thermophila in the presence of the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate.

    Science.gov (United States)

    Fernández-Fernández, María; Moldes, Diego; Domínguez, Alberto; Sanromán, M Ángeles; Tavares, Ana Paula M; Rodríguez, Oscar; Macedo, Eugénia A

    2014-01-01

    The use of ionic liquids (ILs) as reaction media for enzymatic reactions has increased their potential because they can improve enzyme activity and stability. Kinetic and stability properties of immobilized commercial laccase from Myceliophthora thermophila in the water-soluble IL 1-ethyl-3-methylimidazolium ethylsulfate ([emim][EtSO4 ]) have been studied and compared with free laccase. Laccase immobilization was carried out by covalent binding on glyoxyl-agarose beads. The immobilization yield was 100%, and the activity was totally recovered. The Michaelis-Menten model fitted well to the kinetic data of enzymatic oxidation of a model substrate in the presence of the IL [emim][EtSO4 ]. When concentration of the IL was augmented, the values of Vmax for free and immobilized laccases showed an increase and slight decrease, respectively. The laccase-glyoxyl-agarose derivative improved the laccase stability in comparison with the free laccase regarding the enzymatic inactivation in [emim][EtSO4 ]. The stability of both free and immobilized laccase was slightly affected by small amounts of IL (<50%). A high concentration of the IL (75%) produced a large inactivation of free laccase. However, immobilization prevented deactivation beyond 50%. Free and immobilized laccase showed a first-order thermal inactivation profile between 55 and 70°C in the presence of the IL [emim][EtSO4 ]. Finally, thermal stability was scarcely affected by the presence of the IL.

  19. Synthesis of Highly Polymerized Water-soluble Cellulose Acetate by the Side Reaction in Carboxylate Ionic Liquid 1-ethyl-3-methylimidazolium Acetate

    Science.gov (United States)

    Pang, Jinhui; Liu, Xin; Yang, Jun; Lu, Fachuang; Wang, Bo; Xu, Feng; Ma, Mingguo; Zhang, Xueming

    2016-09-01

    In the present study, we describe a novel one-step method to prepare water-soluble cellulose acetate (WSCA) with higher degree of polymerization values (DP = 650–680) by in situ activation of carboxyl group in ionic liquid. First of all, cellulose was dissolved in 1-ethyl-3-methylimidazolium acetate (EmimAc) and reacted with dichloroacetyl chloride (Cl2AcCl) in order to make cellulose dichloroacetate. Under various conditions, a series of water soluble products were produced. Elemental analysis and NMR results confirmed that they were cellulose acetate with DS (degree of substitution) values in the range from 0.30 to 0.63. NMR studies demonstrated that Cl2AcCl reacted with acetate anion of EmimAc producing a mixed anhydride that acetylated cellulose. Other acylating reagents such as benzoyl chloride, chloroacetyl chloride can also work similarly. 2D NMR characterization suggested that 6-mono-O-acetyl moiety, 3,6-di-O-acetylcellulose and 2,6-di-O-acetyl cellulose were all synthesized and the reactivity of hydroxyl groups in anhydro-glucose units was in the order C-6>C-3>C-2. This work provides an alternative way to make WSCA, meanwhile, also services as a reminder that the activity of EmimAc toward carbohydrate as acylating reagents could be a problem, because the expected acylated products may not be resulted and recycling of this ionic liquid could also be difficult.

  20. Synthesis of Highly Polymerized Water-soluble Cellulose Acetate by the Side Reaction in Carboxylate Ionic Liquid 1-ethyl-3-methylimidazolium Acetate

    Science.gov (United States)

    Pang, Jinhui; Liu, Xin; Yang, Jun; Lu, Fachuang; Wang, Bo; Xu, Feng; Ma, Mingguo; Zhang, Xueming

    2016-01-01

    In the present study, we describe a novel one-step method to prepare water-soluble cellulose acetate (WSCA) with higher degree of polymerization values (DP = 650–680) by in situ activation of carboxyl group in ionic liquid. First of all, cellulose was dissolved in 1-ethyl-3-methylimidazolium acetate (EmimAc) and reacted with dichloroacetyl chloride (Cl2AcCl) in order to make cellulose dichloroacetate. Under various conditions, a series of water soluble products were produced. Elemental analysis and NMR results confirmed that they were cellulose acetate with DS (degree of substitution) values in the range from 0.30 to 0.63. NMR studies demonstrated that Cl2AcCl reacted with acetate anion of EmimAc producing a mixed anhydride that acetylated cellulose. Other acylating reagents such as benzoyl chloride, chloroacetyl chloride can also work similarly. 2D NMR characterization suggested that 6-mono-O-acetyl moiety, 3,6-di-O-acetylcellulose and 2,6-di-O-acetyl cellulose were all synthesized and the reactivity of hydroxyl groups in anhydro-glucose units was in the order C-6>C-3>C-2. This work provides an alternative way to make WSCA, meanwhile, also services as a reminder that the activity of EmimAc toward carbohydrate as acylating reagents could be a problem, because the expected acylated products may not be resulted and recycling of this ionic liquid could also be difficult. PMID:27644545

  1. Studies on the solvation dynamics of coumarin 153 in 1-ethyl-3-methylimidazolium alkylsulfate ionic liquids: dependence on alkyl chain length.

    Science.gov (United States)

    Das, Sudhir Kumar; Sarkar, Moloy

    2012-08-06

    Steady-state and time-resolved fluorescence behavior of coumarin 153 (C153) is investigated in a series of 1-ethyl-3-methylimidazolium alkylsulfate ([C(2)mim][C(n)OSO(3)]) ionic liquids differing only in the length of the linear alkyl chain (n = 4, 6, and 8) in the anion. The aim of the present study is to understand the role of alkyl chain length in solute rotation and solvation dynamics of C153 in these ionic liquids. The blueshift observed in the steady-state absorption and emission maxima of C153 on going from the C(4)OSO(3) to the C(8)OSO(3) system indicates increasing nonpolar character of the microenvironment of the solute with increasing length of the alkyl side chain of the anion of the ionic liquids. The average solvation time is also found to increase on changing the substituent from butyl to octyl, and this is attributed to the increase in the bulk viscosity of the ILs. A steady blueshift of the time-zero maximum of the fluorescence spectrum with increasing alkyl chain length also indicates that the probe molecule experiences a less polar environment in the early part of the dynamics. Rotational dynamics of C153 are also analyzed by using the Stokes-Einstein-Debye (SED), Gierer-Wirtz (GW), and Dote-Kivelson-Schwartz (DKS) theories. Analyses of the results seem to suggest decoupling of the rotational motion of the probe from solvent viscosity.

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

    Science.gov (United States)

    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.

  3. Thermodynamic properties of ternary mixtures of 1-ethyl-3-methylimidazolium tetrafluoroborate with 1-methyl pyrrolidin-2-one or pyrrolidin-2-one + water

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, V.K., E-mail: v_sharmachem58@rediffmail.com [Department of Chemistry, M. D. University, Rohtak, Haryana (India); Bhagour, S. [Department of Chemistry, M. D. University, Rohtak, Haryana (India); Sharma, D. [P.D.M. College of Engineering for Women, Bahadurgarh, Haryana (India); Solanki, S. [Department of Chemistry, M. D. University, Rohtak, Haryana (India)

    2013-07-10

    Highlights: • The V{sub ijk}{sup E} and (κ{sub S}{sup E}){sub ijk} data have been measured over entire mole fraction at 4 temperature. • The V{sub ijk}{sup E} and (κ{sub S}{sup E}){sub ijk} data have been fitted to Redlich–Kister equation. • The observed data have been analyzed in terms of Graph theory. • The V{sub ijk}{sup E} and (κ{sub S}{sup E}){sub ijk} values predicted by Graph theory compare well with experimental values. - Abstract: Densities, ρ{sub ijk} and speeds of sound, u{sub ijk} of 1-ethyl-3-methylimidazolium tetrafluoroborate (i) + 1-methyl pyrrolidin-2-one or pyrrolidin-2-one (j) + water (k) ternary mixtures have been measured over the complete mole fraction range at 293.15, 298.15, 303.15, and 308.15 K using density and speed of sound analyzer (Anton Paar DSA 5000). The heat capacity, Cp of water at 293.15, 298.15, 303.15, and 308.15 K have also been measured using differential scanning calorimeter (Model – μDSC 7 Evo). The measured data have been employed to determine excess molar volumes, V{sub ijk}{sup E} and excess isentropic compressibilities, (κ{sub S}{sup E}){sub ijk}. The V{sub ijk}{sup E} and (κ{sub S}{sup E}){sub ijk} data have been fitted to Redlich–Kister equation to calculate ternary adjustable parameters and standard deviations. The observed thermodynamic properties of the ternary mixtures have been analyzed in terms of Graph theory. It has been observed that Graph theory successfully describes well V{sub ijk}{sup E} and (κ{sub S}{sup E}){sub ijk} data of the studied ternary ionic liquid mixtures.

  4. Electrochemistry in ultrahigh vacuum: underpotential deposition of Al on polycrystalline W and Au from room temperature AlCl(3)/1-ethyl-3-methylimidazolium chloride melts.

    Science.gov (United States)

    Johnston, Matthew; Lee, Jae-Joon; Chottiner, Gary S; Miller, Barry; Tsuda, Tetsuya; Hussey, Charles L; Scherson, Daniel A

    2005-06-09

    The voltammetric characteristics of polycrystalline Au and W electrodes cleaned (thermal annealing at 1100 K) and characterized (Auger electron spectroscopy) in ultrahigh vacuum (UHV) have been examined in ultrapure AlCl(3)/1-ethyl-3-methylimidazolium chloride (EtMeImCl) melts in UHV. These experiments were performed using a custom-designed transfer system that allows for the all-Al electrochemical cell to be filled with EtMeImCl in an auxiliary UHV chamber and later transferred under UHV to the main UHV chamber that houses the Auger electron spectrometer. The results obtained for the underpotential (UPD) and bulk deposition of Al on Au were found to be very similar to those reported in the literature for measurements carried out under 1 atm of an inert gas in a glovebox. For the far more reactive W surfaces, voltammetric features ascribed to the stripping of underpotential-deposited Al could be observed following a single scan from 1.0 V vs Al(3+)/Al to a potential negative enough for bulk deposition of Al to ensue. This behavior is unlike that reported in the literature for experiments performed in a glovebox, which required either extensive potential cycling in the Al bulk deposition and stripping region or excursions to potentials positive enough for chlorine evolution to ensue for Al UPD features to be clearly discerned. These observations open new prospects for fundamental electrochemical studies of well-characterized, highly reactive metals, including single crystals, in a variety of low vapor pressure ionic liquids.

  5. Dissolution and regeneration of microcrystalline cellulose in 1-ethyl-3-methylimidazolium diethylphosphate%微晶纤维素在EMIM-DEP中的溶解与再生

    Institute of Scientific and Technical Information of China (English)

    陶伟娜; 王少君; 李飞

    2012-01-01

    1-Ethyl-3-methylimidazolium diethylphosphate (EMIM-DEP) is synthesized with microwave method and is used to dissolve microcrystalline cellulose in this study. Its dissolution process is observed by polarizing microscope. With the rise of temperature the solubility of cellulose increases. Ultrasonic auxiliary can improve well the solubility of microcrystalline cellulose in ionic liquids. The regenerated cellulose is characterized by FT-IR, XRD, SEM and TGA. The results show that the microcrystalline cellulose in EMIM-DEP is dissolved directly without derivative reaction. The regenerated cellulose is changed from cellulose I into cellulose II in crystal style. Recovered ionic liquid has no change in structure and can be reused with good dissolving ability for microcrystalline cellulose.%通过微波法合成1-乙基-3-甲基咪唑磷酸二乙酯离子液体(EMIM-DEP)并用其溶解微晶纤维素.用偏光显微镜观察微晶纤维素在离子液体中的溶解.随温度的升高纤维素的溶解度增加,超声辅助可以很好地提高微晶纤维素在离子液体中的溶解度.溶解之后再生的纤维素通过红外光谱(FT-IR)、X-射线衍射(XRD)、扫描电镜(SEM)和热重分析(TGA)表征,结果显示微晶纤维素在EMIM-DEP中是直接溶解没有发生衍生反应;再生的纤维素晶型由纤维素Ⅰ型转化为纤维素Ⅱ型;回收后的离子液体结构没发生变化,重复利用仍保持较好的溶解微晶纤维素的能力.

  6. Physiochemical Properties of Hydrodenitrification and Hydrodesulphurization Inhibiting Compounds with 1-Ethyl-3-Methylimidazolium Ethylsulphate at T = (298.15 to 323.15 K and =1 Bar

    Directory of Open Access Journals (Sweden)

    Ramalingam Anantharaj

    2011-01-01

    Full Text Available This work investigates the ability of 1-ethyl-3-methylimidazolium ethylsulphate ([emim][EtSO4] as a green and tuneable solvent for denitrification and desulphurization of diesel oil. Experimental density, surface tension, and refractive index data have been measured for the following systems: [emim][EtSO4](1 + pyridine(2, [emim][EtSO4](1+ pyrrole(2, [emim][EtSO4](1 + quinoline(2, [emim][EtSO4](1 + indoline(2, [emim][EtSO4](1 + thiophene(2, and [emim][EtSO4](1 + water(2 over the entire mole fraction of [emim][EtSO4] at temperatures of (298.15 to 323.15 K and at atmospheric pressure. Further, from experimental density values, coefficient of thermal expansivity and excess molar volume were also calculated. It was found that the heteroaromatic nitrogen/sulphur compounds and water are completely miscible in the [emim][EtSO4] ionic liquid. The surface tension values were found to increase while the refractive index decrease with increasing mole fraction of [emim][EtSO4]. On the other hand, dissimilar molecule such as water showed mobility of ions on mixing resulting in lower surface tension. The experimental values of surface tension increased in the order: thiophene > pyridine > pyrrole > indoline > quinoline and for refractive index: quinoline > indoline > pyrrole > pyridine > thiophene > water. It was found that the composition of [emim][EtSO4] has a greater influence than temperature in deciding the densities, surface, optical, and thermodynamic properties.

  7. 离子液体1-乙基-3-甲基咪唑醋酸盐的制备及用于纤维素溶解纺丝的研究进展%Progress in Preparation of Ionic Liquid 1-Ethyl-3-Methylimidazolium Acetate and Application in Dissolution and Spinning of Cellulose

    Institute of Scientific and Technical Information of China (English)

    程春祖; 朱庆松; 孙玉山; 李晓俊; 徐纪刚

    2011-01-01

    离子液体1-乙基-3-甲基咪唑醋酸盐([EMIM3Ac)可以溶解天然高分子等许多聚合物,尤其对于纤维素具有较强的溶解能力,且溶解过程基本不造成纤维素降解,故可以作为纤维素的有效溶剂,用于纤维素的溶解加工。与其它溶剂相比,[EMIM]Ac具有使用安全、不污染环境、易回收循环利用等优势,故在纤维素溶解、纺丝方面具有广阔的应用前景。本文主要介绍了[EMIM]Ac的多种制备方法及其优缺点,这对其它醋酸盐类离子液体的制备也具有指导意义;并概述了[EMIM]Ac在纤维素溶解、纺丝等方面的应用研究。%Ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM]Ae), which has stronger ability to dissolve cellulose especially, can be used to dissolve natural polymer and many other polymers. As the dissolving process of cellulose causes no degradation, [EMIM]Ac can be used as an effective solution in dissolving and proeessing of eellulose. Compared with other solutions, [EMIM]Ae has many advantages of use safety, no pollution to environment and easy recovery recycling, and has wide application prospect in the dissolving and spinning of cellulose. Various preparation methods of [EMIM]Ac and their advantages or disadvantages are introduced in this paper, which have a guiding significance to the preparations of other acetic acid salts ionic liquid. And the application research of [EMIM]Ac in cellulose dissolving and spinning is summarized.

  8. Measurement and Correlation of the Phase Diagram Data for 1-Ethyl-3-methylimidazolium Dimethyl phosphate+K3PO4/ K2HPOjK2CO3+ H20 Ionic Liquids Aqueous Two-Phase Systems at T-- 298.15 K%1-乙基-3-甲基咪唑磷酸二甲酯盐+K3P04/K2HP04/K2C03+H20离子液体双水相体系在T=298.15K时相图数据的测量和相关性

    Institute of Scientific and Technical Information of China (English)

    王良; 朱红; 闫永胜

    2012-01-01

    实验测定了1-乙基-3.甲基咪唑磷酸二甲酯盐(1-ethyl-3-methylimidazolium dimehtyl phosphate, [Emim]DMP )+盐(K3P04,K2HP04和K2C03)+H20体系在298.15K的双节点数据.用3个经验方程与双节点数据关联,发现Merchuk方程简便并且准确性好.不同盐的分相能力顺序为K3P04〉K2HP04〉K2C03,这与水合离子Gibbs自由能(△hydG)有关.用Othmer.Tobias方程、Bancroft方程和二元参数方程计算此方法和相应系线数据的可靠性.[Emim]DMP是常见的离子液体,广泛用于萃取石油燃料中的硫.报道T[Emim]DMP+盐+H20体系的相图数据.%Binodal data for the 1-ethyl-3-methylimidazolium dimethyl phosphate ([Emim]DMP)+salt (K3PO4, K2HPO4, and K2CO3)q-H20 systems were experimentally determined at 298.15 K. Three empirical equations were used to correlate binodal data. The Merchuk equation is an uncomplicated one for fine accu racy. The ability of different salts studied for phase separation are in the order of K3PO4 〉 K2HPO4 〉 K2CO3, which may be related to the Gibbs free energy of hydration of the ions (AhydG). The reliability of the calcula tion method and the corresponding tie-line data was described by the Othmer-Tobias equation and Bancroft equation, as well as the twoparameter equation. [Emim]DMP is a familiar ionic liquid, which is extensively used for extractive desulfurization of fuel oils. This is the first time to report the data for phase diagrams of [Emim]DMP 4- salt + water systems.

  9. Thermal Decomposition Mechanism of 1-ethyl-3-methylimidazolium Bromide Ionic Liquid (Preprint)

    Science.gov (United States)

    2011-09-14

    calculated values for the SN2 reactions . Comparisons of product photoionization efficiency (PIE) curves with literature data are in good agreement...methyl and ethyl bromides were evaluated experimentally, and found to be in agreement with calculated values for the SN2 reactions . Comparisons of...contrary to what is observed experimentally. However, for the SN2 reactions , the transition state barriers and reaction enthalpies are in good

  10. Electroreduction of Benzoylformic Acid in 1-Ethyl-3-methylimidazolium Bromide Room Temperature Ionic Liquid

    Institute of Scientific and Technical Information of China (English)

    SUN Qian; ZHAO Peng; LU Jia-xing; HE Ming-yuan

    2005-01-01

    @@ Introduction The chemical industry is under considerable pressure to replace many volatile organic compounds that are widely used as solvents in organic synthesis. This trend leads to the exploration for novel reaction media. Room temperature ionic liquids as environmentally benign media for organic synthesis and catalytic reactions have been gradually recognized and accepted[1,2].

  11. Volatilization Mechanism of 1-Ethyl-3-methylimidazolium Bromide Ionic Liquid (Briefing Charts)

    Science.gov (United States)

    2012-04-01

    Distribution A: Approved for public release; distribution unlimited JPC -A 2008, 112, 7816 Hypergolic Ignition Autoignition at ambient P & T MMH...Tf2N]: 8.59 ± 0.03 eV PIE curves and structures C+A- + h C+A + e- C+ + A + e- JPC -A 2010, 114, 879 • Dissociative photoionization

  12. Microscopic structures of ionic liquids 1-ethyl-3-methylimidazolium tetrafluoroborate in water probed by the relative chemical shift

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The relative chemical shifts (△δ) △δwere put forward to investigate the microscopic structure of 1-ethyl-3-methyl-imidazolium tetrafluoroborate (EmimBF4) during the dilution process with water.The concentration-dependent △δ(C2)H-(C4)H,△δ(C2)H-(C5)H and △δ(C4)H-(C5)H were analyzed.The results reveal that the variations of the microscopic structures of three aromatic protons are inconsistent.The strength of the H-bond between water and three aromatic protons follows the order:(C2)H···O > (C4)H···O > (C5)H···O.The concentration-dependent △δ(C6)H-(C7)H and △δ(C6)H-(C8)H indicate the formation of the H-bonds of (Calkyl)H···O is impossible,and more water is located around (C6)H than around (C7)H or (C8)H.The concentration-dependent △δ(C2)H-(C4)H and △δ(C2)H-(C5)H both increase rapidly when xwater > 0.9 or so,suggesting the ionic pairs of EmimBF4 are dissociated rapidly.The turning points of concentration-dependent △δ(C2)H-(C4)H and △δ(C2)H-(C5)H indicate that some physical properties of the EmimBF4/water mixtures also change at the corresponding concentration point.The microscopic structures of EmimBF4 in water could be clearly detected by the relative chemical shifts.

  13. Synergistic Effect of Combining Titanosilicate and 1-Ethyl-3-Methylimidazolium Acetate in Mixed Matrix Membranes for Efficient C02 Separation

    Directory of Open Access Journals (Sweden)

    Maria Del Mar López Guerrero

    2015-06-01

    Full Text Available The separation and capture of CO2 from these sources is becoming important for greenhouse emission. The membrane-based separation process use to remove CO2 takes advantages in energy efficient and environmentally friendly aspects and has been recognized as an important technology for CO2 capture and gas separation. The novel mixed matrix membranes (MMMs were fabricated by incorporating microporous titanosilicate ETS-10 and a highly CO2 absorbent ionic liquid , [EMIM][Ac] into a Chitosan (CS matrix to improve CO2 separation performance, and were prepared, characterized and tested for CO2 and N2. The solubility values show that the CO2 solubility increases upon addition of ETS-10 particles. The N2 solubility in the ETS-10/[EMIM][Ac]/CS was reduced, while CO2 solubility remained constant. FT-IR spectra revealed a good interaction between the components in the MMMs. Subtle differences in the intensity and position of all individual bands, were observed in the region between 3600 and 2700 cm-1 and 1700 and 900 cm-1. These indicated bonding of the components in the film, confirming the good interaction existing among the components, and that may account for the higher flexibility of the hybrid membrane materials imparted to both CS and ETS-10/CS MMMs, , due to the singular interaction between CS and [EMIM][Ac]. Keywords: CO2 solubility, CO2 separation, microporous titanosilicate ETS-10, Chitosan, mixed matrix membranes (MMMs.

  14. Immobilization of laccase on modified silica: stabilization, thermal inactivation and kinetic behaviour in 1-ethyl-3-methylimidazolium ethylsulfate ionic liquid.

    Science.gov (United States)

    Tavares, Ana P M; Rodríguez, Oscar; Fernández-Fernández, María; Domínguez, Alberto; Moldes, Diego; Sanromán, María A; Macedo, Eugénia A

    2013-03-01

    Laccase was immobilized on modified silica carrier. The immobilization conditions, pH and enzyme concentration were optimized. Operational stability of 10 reaction cycles showed that immobilized laccase in buffer was stable, presenting an activity loss 80% was obtained in ionic liquid (IL) solution. Activity of immobilized laccase was maintained when incubated in IL. After 7days of incubation, immobilized laccase lost 30-50% of its initial activity. Immobilization also improved thermal stability of laccase in the presence of IL. Enzyme kinetics was modelled with Michaelis-Menten model. The Km value for free laccase increases significantly with the IL concentration. Slight differences were found in Vm for free enzyme. Unusual kinetic behaviour was obtained for immobilized laccase in IL: Both Vm and Km increased with IL concentration, resulting in increased catalytic efficiency of the immobilized enzyme in presence of IL.

  15. Helium Nanodroplet Isolation and Infrared Spectroscopy of the Isolated Ion-Pair 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide

    Science.gov (United States)

    2013-09-01

    making ionic liquids potentially useful for batteries,3-5 solar cells,6, 7 fuel cells,8, 9 and as “green” solvents10 for organic synthesis and...ionic nature of the liquid. Earle and co-workers were the first to demonstrate, however, that the vacuum distillation of certain families of aprotic...Conversion Efficiency of Dye-Sensitized Solar Cells. J. Phys. Chem. B 2003, 107, 13280-13285.     7. Zakeeruddin, S. M.; Wang, P.; Wenger, B.; Humphry

  16. Local environment structure and dynamics of CO2 in the 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and related ionic liquids

    Science.gov (United States)

    Lourenço, Tuanan C.; Aparicio, Santiago; Costa, Gabriela C.; Costa, Luciano T.

    2017-03-01

    Despite the innumerous papers regarding the study of the ionic liquids as a potential candidate for CO2 capture, many details concerning the structure and dynamics of CO2 in the system are still to be revealed, i.e., the correlation between the local environment structure and the dynamic properties of the substance. This present work relied on the performance of molecular dynamics both for the neat [C2mim][Tf2N] and [C2mim][Tf2N]/CO2 mixtures in an attempt to elucidate the local environment of CO2 and their effects on the dynamic properties of [C2mim][Tf2N]. A slight change in the orientation of the cation and anion could be observed, which was correlated to the cation and anion moving away from each other in order to receive the carbon dioxide. The gas molecules pushed both the cation and the anion away to create sufficient void to its accommodation. The diffusion coefficient of [C2mim]+ is higher than [Tf2N]- regardless the increase of the CO2 concentration. The addition of CO2 in the ionic liquid has shown an increase of 4-5 times for the diffusivity of ions, which was related to the decrease of cation-anion interaction strength. The transport properties' results showed that the addition of CO2 in the ionic liquid generates the fluidization of the system, decreasing the viscosity as a consequence of the local environment structure changing. Likewise, the effect of the type of anion and cation on the system properties was studied considering [Ac]- and [BMpyr]+ ions, showing large effects by the change of anion to [Ac]- which rise from the strong [C2mim]+-[Ac]- interaction, which conditions the solvation of ions by CO2 molecules.

  17. Dynamics Simulations and Statistical Modeling of Thermal Decomposition of 1-Ethyl-3-methylimidazolium Dicyanamide and 1-Ethyl-2,3-dimethylimidazolium Dicyanamide

    Science.gov (United States)

    2014-10-02

    vibrational modes of EMIM+DCA−. The decomposition trajectories can be grouped into six classes, as described below along with their contributions (i.e... group from the N3 position, while others underwent methyl abstraction via an SN2 mechanism, yielding ethylimidazole and CH3DCA with a reaction enthalpy of...the imidazolium cation is significantly reduced upon substitution of a methyl group for a hydrogen atom at this position. The present work

  18. Electrodeposition of Al in 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ionic liquids: in situ STM and EQCM studies.

    Science.gov (United States)

    Moustafa, E M; El Abedin, S Zein; Shkurankov, A; Zschippang, E; Saad, A Y; Bund, A; Endres, F

    2007-05-10

    In the present paper, the electrodeposition of Al on flame-annealed Au(111) and polycrystalline Au substrates in two air- and water-stable ionic liquids namely, 1-butyl-1-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)amide, [Py(1,4)]Tf(2)N, and 1-ethyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)amide, [EMIm]Tf(2)N, has been investigated by in situ scanning tunneling microscopy (STM), electrochemical quartz crystal microbalance (EQCM), and cyclic voltammetry. The cyclic voltammogram of aluminum deposition and stripping on Au(111) in the upper phase of the biphasic mixture of AlCl(3)/[EMIm]Tf(2)N at room temperature (25 degrees C) shows that the electrodeposition process is completely reversible as also evidenced by in situ STM and EQCM studies. Additionally, a cathodic peak at an electrode potential of about 0.55 V vs Al/Al(III) is correlated to the aluminum UPD process that was evidenced by in situ STM. A surface alloying of Al with Au at the early stage of deposition occurs. It has been found that the Au(111) surface is subject to a restructuring/reconstruction in the upper phase of the biphasic mixture of AlCl(3)/[Py(1,4)]Tf(2)N at room temperature (25 degrees C) and that the deposition is not fully reversible. Furthermore, the underpotential deposition of Al in [Py(1,4)]Tf(2)N is not as clear as in [EMIm]Tf(2)N. The frequency shift in the EQCM experiments in [Py(1,4)]Tf(2)N shows a surprising result as an increase in frequency and a decrease in damping with bulk aluminum deposition at potentials more negative than -1.8 V was observed at room temperature. However, at 100 degrees C there is a frequency decrease with ongoing Al deposition. At -2.0 V vs Al/Al(III), a bulk aluminum deposition sets in.

  19. A SAXS study on nanostructure evolution in water free membranes containing ionic liquid: from dry membrane to saturation.

    Science.gov (United States)

    Sekhon, Satpal Singh; Park, Jin-Soo; Choi, Young-Woo

    2010-11-07

    Small-angle X-ray scattering (SAXS) technique has been used to study the evolution of ionomer peak in the recast Nafion membranes containing the ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF(4)). To the best of our knowledge, this is the first report dealing with the study of membranes containing different concentrations of the ionic liquid (EMIBF(4)), from the dry (no ionic liquid) to the saturation (containing 70 wt% ionic liquid) state to understand the evolution of the ionomer peak and the formation of ionic aggregates in these anhydrous membranes. The small-angle scattering maximum (ionomer peak) has been observed to shift continuously toward lower scattering vector (q) values as the ionic liquid content increases. The ionic conductivity behavior for the membranes containing ionic liquid has been found to be closely related with the change of slope of the double logarithmic plot between the reciprocal of the position of the ionomer peak and the polymer weight fraction. The q region over which Porod's law has been obeyed in different membranes was initially narrow and has been observed to widen with an increase in the content of the ionic liquid.

  20. Electrochemical behavior of high performance on-chip porous carbon films for micro-supercapacitors applications in organic electrolytes

    Science.gov (United States)

    Brousse, K.; Huang, P.; Pinaud, S.; Respaud, M.; Daffos, B.; Chaudret, B.; Lethien, C.; Taberna, P. L.; Simon, P.

    2016-10-01

    Carbide derived carbons (CDCs) are promising materials for preparing integrated micro-supercapacitors, as on-chip CDC films are prepared via a process fully compatible with current silicon-based device technology. These films show good adherence on the substrate and high capacitance thanks to their unique nanoporous structure which can be fine-tuned by adjusting the synthesis parameters during chlorination of the metallic carbide precursor. The carbon porosity is mostly related to the synthesis temperature whereas the thickness of the films depends on the chlorination duration. Increasing the pore size allows the adsorption of large solvated ions from organic electrolytes and leads to higher energy densities. Here, we investigated the electrochemical behavior and performance of on-chip TiC-CDC in ionic liquid solvent mixtures of 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4) diluted in either acetonitrile or propylene carbonate via cyclic voltammetry and electrochemical impedance spectroscopy. Thin CDC films exhibited typical capacitive signature and achieved 169 F cm-3 in both electrolytes; 65% of the capacitance was still delivered at 1 V s-1. While increasing the thickness of the films, EMI+ transport limitation was observed in more viscous PC-based electrolyte. Nevertheless, the energy density reached 90 μW h cm-2 in 2M EMIBF4/ACN, confirming the interest of these CDC films for micro-supercapacitors applications.

  1. 乙基甲基咪唑磷酸二甲酯+甲醇/乙醇+水三元工质溶液混合焓的测量及关联%Measurement and Correlation of Excess Mole Enthalpy of Ternary Working Solutions 1-Ethyl-3-Methylimidazolium Dimethylphosphate+Methanol/or Ethanol+Water

    Institute of Scientific and Technical Information of China (English)

    张晓冬; 于静

    2013-01-01

    采用绝热量热法测量了由离子液体1-乙基-3-甲基咪唑磷酸二甲酯[EMIM] [DMP]分别与CH3OH/C2HsOH和H2O所组成的两组三元工质溶液体系[EMIM] [DMP] (1) +CH3OH(2)/C2 H5OH (2) +H2O (3)在298.15 K,常压下的摩尔混合焓HEm.采用Redlich-Kister (RK)方程以及Nagata和Tamura(NT)提出的多项式方程对实验数据进行关联.结果表明,两组三元体系的混合焓在实验浓度范围内均为负值,混合为放热过程,具有成为吸收制冷循环新工质溶液的基本特征.混合焓的关联值与实验值的平均相对误差分别为0.90%和0.88%.

  2. Graphene-based supercapacitors in the parallel-plate electrode configuration: ionic liquids versus organic electrolytes.

    Science.gov (United States)

    Shim, Youngseon; Kim, Hyung J; Jung, Younjoon

    2012-01-01

    Supercapacitors with two single-sheet graphene electrodes in the parallel plate geometry are studied via molecular dynamics (MD) computer simulations. Pure 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI+BF4-) and a 1.1 M solution of EMI+BF4- in acetonitrile are considered as prototypes of room-temperature ionic liquids (RTILs) and organic electrolytes. Electrolyte structure, charge density and associated electric potential are investigated by varying the charges and separation of the two electrodes. Multiple charge layers formed in the electrolytes in the vicinity of the electrodes are found to screen the electrode surface charge almost completely. As a result, the supercapacitors show nearly an ideal electric double layer behavior, i.e., the electric potential exhibits essentially a plateau behavior in the entire electrolyte region except for sharp changes in screening zones very close to the electrodes. Due to its small size and large charge separation, BF4- is considerably more efficient in shielding electrode charges than EMI+. In the case of the acetonitrile solution, acetonitrile also plays an important role by aligning its dipoles near the electrodes; however, the overall screening mainly arises from ions. Because of the disparity of shielding efficiency between cations and anions, the capacitance of the positively-charged anode is significantly larger than that of the negatively-charged cathode. Therefore, the total cell capacitance in the parallel plate configuration is primarily governed by the cathode. Ion conductivity obtained via the Green-Kubo (GK) method is found to be largely independent of the electrode surface charge. Interestingly, EMI+BF4- shows higher GK ion conductivity than the 1.1 M acetonitrile solution between two parallel plate electrodes.

  3. Nanoporous carbon supercapacitors in an ionic liquid: a computer simulation study.

    Science.gov (United States)

    Shim, Youngseon; Kim, Hyung J

    2010-04-27

    Supercapacitors composed of carbon nanotube (CNT) micropores in the room-temperature ionic liquid (RTIL) 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI+BF4(-)) are studied via molecular dynamics (MD)computer simulations. It is found that the distribution of RTIL ions inside the micropore varies significantly with the pore size. Internal solvation of small (6,6) and (7,7) CNTs with an electrified interior wall is effected almost exclusively via counterions. Surprisingly, these counterions, even though they all have the same charge, lead to a charge density characterized by multiple layers with alternating signs. This intriguing feature is attributed to the extended nature of RTIL ion charge distributions, which result in charge separation through preferential orientation inside the electrified nanotubes. In the case of larger (10,10) and (15,15) CNTs, counterions and coions develop multilayer solvation structures. The specific capacitance normalized to the pore surface area is found to increase as the CNT diameter decreases from (15,15) to (7,7). As the pore size further reduces from (6,6) to(5,5), however, the specific capacitance diminishes rapidly. These findings are in excellent agreement with recent experiments with carbon-based materials. A theoretical model based on multiple charge layers is proposed to understand both the MD and experimental results.

  4. Enzyme activity in dialkyl phosphate ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Enzyme activity in dialkyl phosphate ionic liquids.

    Science.gov (United States)

    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.

  6. Preparation of microfibers from wood/ionic liquid solutions.

    Science.gov (United States)

    Polaskova, Martina; Cermak, Roman; Verney, Vincent; Ponizil, Petr; Commereuc, Sophie; Gomes, Margarida F Costa; Padua, Agilio A H; Mokrejs, Pavel; Machovsky, Michal

    2013-01-30

    Two types of ionic liquids, 1-ethyl-3-methylimidazolim acetate and 1-ethyl-3-methylimidazolium lactate, were employed for the direct processing of pine wood into microfibers. The concentration of 5 wt.% of wood in ionic liquids was rated as the most appropriate for electrospinning. The fibers were electrospun into the collector water bath. The final structure varied from individual microfibers to fiber bundles. It was demonstrated that 1-ethyl-3-methylimidazolium lactate is a powerful solvent and provides the direct transformation of pristine pine wood into the non-wovens.

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

    NARCIS (Netherlands)

    Meindersma, G. Wytze; Podt, Anita J.G.; Haan, de André B.

    2006-01-01

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

  8. Ionothermal synthesis and crystal structures of metal phosphate chains

    NARCIS (Netherlands)

    Wragg, D.; Le Ouay, B.; Beale, A.M.; O'Brien, M.G.; Slawin, A.M.Z.; Warren, J.E.; Prior, T.J.; Morris, R.E.

    2013-01-01

    We have prepared isostructural aluminium and gallium phosphate chains by ionothermal reactions in 1-ethyl-3-methylimidazolium bromide and 1-ethylpyridinium bromide under a variety of conditions. The chains can be prepared as pure phases or along with three dimensional framework phases. The chains ar

  9. Electropolymerization of O-Phenylenediamine in an Ionic Liquid

    Institute of Scientific and Technical Information of China (English)

    Yan Fang DU; Xi Min QI; Peng ZHAO; Jia Xing LU; Ming Yuan HE

    2004-01-01

    Ionic liquid like 1-ethyl-3-methylimidazolium bromine ([EMIM]Br) has been used as electrolyte for the electropolymerization of O-phenylenediamine at glassy carbon electrode by cyclic voltammetry. It is found that poly (O-phenylenediamine) film modified electrode has favorable electrochemical activity in acid solution.

  10. Soft and flexible conductive PDMS/MWCNT composites

    DEFF Research Database (Denmark)

    Hassouneh, Suzan Sager; Yu, Liyun; Skov, Anne Ladegaard;

    2017-01-01

    Conductive elastomers based on MWCNT in polydimethylsiloxane (PDMS) have been prepared by a range of dispersion methods such as ultrasonication, speedmixing and roll milling in combination with physical or covalent modification. The ionic liquid (IL), 1-ethyl-3-methylimidazolium bis(trifluorometh......Conductive elastomers based on MWCNT in polydimethylsiloxane (PDMS) have been prepared by a range of dispersion methods such as ultrasonication, speedmixing and roll milling in combination with physical or covalent modification. The ionic liquid (IL), 1-ethyl-3-methylimidazolium bis...... in conductivity was observed, which was attributed to a change in morphology occurring between 4 and 5 wt % MWCNT. As an alternative to IL dispersing aids a novel functionalized MWCNT was prepared by free radical polymerization using α-methacryloxypropyl-polydimethylsiloxane, which could be used directly...

  11. The rechargeable aluminum-ion battery

    KAUST Repository

    Jayaprakash, N.

    2011-01-01

    We report a novel aluminium-ion rechargeable battery comprised of an electrolyte containing AlCl3 in the ionic liquid, 1-ethyl-3-methylimidazolium chloride, and a V2O5 nano-wire cathode against an aluminium metal anode. The battery delivered a discharge capacity of 305 mAh g-1 in the first cycle and 273 mAh g-1 after 20 cycles, with very stable electrochemical behaviour. © The Royal Society of Chemistry 2011.

  12. Technologies for Developing Predictive Atomistic and Coarse-Grained Force Fields for Ionic Liquid Property Prediction

    Science.gov (United States)

    2008-07-29

    Butanesulfonate (some parameters for 1-ethyl-3-methylimidazolium cation taken from the work of Cadena et al).2 I. Intramolecular terms (bond, angles...parameters for the anions of (A) and (B). Dihedral parameters for the cation of (B) were taken directly from the work of Cadena et al.2 Dihedral...19586. 2 Cadena , C.; Anthony, J. L.; Shah, J. K.; Morrow, T. I.; Brennecke, J. F.; Maginn, E. J. J. Am. Chem. Soc., 2004, 126, 5300 3 Schmidt

  13. Density and molar volumes of imidazolium-based ionic liquid mixtures and prediction by the Jouyban-Acree model

    Science.gov (United States)

    Ghani, Noraini Abd; Sairi, Nor Asrina; Mat, Ahmad Nazeer Che; Khoubnasabjafari, Mehry; Jouyban, Abolghasem

    2016-11-01

    The density of imidazolium-based ionic liquid, 1-ethyl-3-methylimidazolium diethylphosphate with sulfolane were measured at atmospheric pressure. The experiments were performed at T= (293 - 343) K over the complete mole fractions. Physical and thermodynamic properties such as molar volumes, V0, and excess molar volumes, VE for this binary mixtures were derived from the experimental density data. The Jouyban-Acree model was exploited to correlate the physicochemical properties (PCPs) of binary mixtures at various mole fractions and temperatures.

  14. The rechargeable aluminum-ion battery.

    Science.gov (United States)

    Jayaprakash, N; Das, S K; Archer, L A

    2011-12-21

    We report a novel aluminium-ion rechargeable battery comprised of an electrolyte containing AlCl(3) in the ionic liquid, 1-ethyl-3-methylimidazolium chloride, and a V(2)O(5) nano-wire cathode against an aluminium metal anode. The battery delivered a discharge capacity of 305 mAh g(-1) in the first cycle and 273 mAh g(-1) after 20 cycles, with very stable electrochemical behaviour.

  15. The rechargeable aluminum-ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Navaneedhakrishnan, Jayaprakash; Das, Shyamal K; Archer, Lynden A.

    2011-01-01

    We report a novel aluminium-ion rechargeable battery comprised of an electrolyte containing AlCl₃ in the ionic liquid, 1-ethyl-3-methylimidazolium chloride, and a V₂O₅ nano-wire cathode against an aluminium metal anode. The battery delivered a discharge capacity of 305 mAh g⁻¹ in the first cycle and 273 mAh g⁻¹ after 20 cycles, with very stable electrochemical behaviour.

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

    Science.gov (United States)

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

    2017-01-10

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

  17. Improvement of biomass properties by pretreatment with ionic liquids for bioconversion process.

    Science.gov (United States)

    Weerachanchai, Piyarat; Leong, Susanna Su Jan; Chang, Matthew Wook; Ching, Chi Bun; Lee, Jong-Min

    2012-05-01

    Cassava pulp residue and rice straw were used as a precursor for pretreatment with ionic liquids to study the effects of pretreatment conditions on product yield and properties. Cassava pulp residue is a potential biomass in the bioconversion process due to it requiring mild pretreatment conditions while providing a high sugar conversion. The maximum sugar conversion and lignin extraction are attained from pretreatment of biomasses with particle size of 1-Ethyl-3-methylimidazolium acetate at 120°C for 24h. The effectiveness of ionic liquid for biomass pretreatment process follows the sequence: 1-Ethyl-3-methylimidazolium acetate>1-Ethyl-3-methylimidazolium diethyl phosphate>1,3-Dimethylimidazolium methyl sulfate. The increase of pretreatment temperature from 25 to 120°C and decrease of biomass particle size renders higher sugar conversion, lignin extraction and lower crystallinity index. However, pretreatment at temperatures higher than 120°C shows a sharp decline of regenerated biomass yield, sugar conversion and lignin extraction and giving higher crystallinity index at pretreatment temperature of 180°C.

  18. Enhanced enzymatic saccharification of kenaf powder after ultrasonic pretreatment in ionic liquids at room temperature.

    Science.gov (United States)

    Ninomiya, Kazuaki; Kamide, Kazuki; Takahashi, Kenji; Shimizu, Nobuaki

    2012-01-01

    This study demonstrates for the first time that the enzymatic hydrolysis of cellulose is drastically enhanced following ultrasonic pretreatment of lignocellulosic material in ionic liquids (ILs) when compared to conventional thermal pretreatment. Five types of ILs, 1-buthyl-3-methylimidazolium chloride (BmimCl), 1-allyl-3-methylimidazolium chloride (AmimCl), 1-ethyl-3-methylimidazolium chloride (EmimCl), 1-ethyl-3-methylimidazolium diethyl phosphate (EmimDep), and 1-ethyl-3-methylimidazolium acetate (EmimOAc) were tested. Cellulose saccharification ratio was about 20% for kenaf powders pretreated in BmimCl, AmimCl, EmimCl, and EmimDep by conventional heating at 110 °C for 120 min. Conversely, 60-95% of cellulose was hydrolyzed to glucose, subsequent to ultrasonic pretreatment in the same ILs for 120 min at 25 °C. The cellulose saccharification ratio of kenaf powder in EmimOAc was 86% after only 15 min of the ultrasonic pretreatment at 25 °C, compared to only 47% in that case of thermal pretreatment in the IL.

  19. Dissolution Behavior of Cellulose in IL + DMSO Solvent: Effect of Alkyl Length in Imidazolium Cation on Cellulose Dissolution

    OpenAIRE

    Airong Xu; Lili Cao; Bingjun Wang; Junying Ma

    2015-01-01

    Four cellulose solvents including [C2mim][CH3COO] + DMSO, [C4mim][CH3COO] + DMSO, [C6mim][CH3COO] + DMSO, and [C8mim][CH3COO] + DMSO were prepared by adding dimethyl sulfoxide DMSO in 1-ethyl-3-methylimidazolium acetate [C2mim][CH3COO], 1-butyl-3-methylimidazolium acetate [C4mim][CH3COO], 1-hexyl-3-methylimidazolium acetate [C6mim][CH3COO], and 1-octyl-3-methylimidazolium acetate [C8mim][CH3COO], respectively. The solubilities of cellulose in these solvents were determined at 25°C. The effect...

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

    Science.gov (United States)

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

    2009-06-05

    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.

  1. Development of an integrated approach for α-pinene recovery and sugar production from loblolly pine using ionic liquids

    DEFF Research Database (Denmark)

    Papa, Gabriella; Kirby, James; Murthy Konda, N. V. S. N.

    2017-01-01

    perspective for the production of advanced cellulosic biofuels. To date, there have been very few examples where a single conversion process has enabled recovery of both terpenes and fermentable sugars in an integrated fashion. We have used the ionic liquid (IL), 1-ethyl-3-methylimidazolium acetate [C2C1Im......][OAc] at 120 °C and 160 °C in conjunction with analytical protocols using GC-MS, to extract α-pinene and simultaneously pretreat the pine to generate high yields of fermentable sugars after saccharification. Compared to solvent extraction, the IL process enabled higher recovery rates for α-pinene, from three...

  2. A high performance hybrid battery based on aluminum anode and LiFePO4 cathode.

    Science.gov (United States)

    Sun, Xiao-Guang; Bi, Zhonghe; Liu, Hansan; Fang, Youxing; Bridges, Craig A; Paranthaman, M Parans; Dai, Sheng; Brown, Gilbert M

    2016-01-28

    A novel hybrid battery utilizing an aluminum anode, a LiFePO4 cathode and an acidic ionic liquid electrolyte based on 1-ethyl-3-methylimidazolium chloride (EMImCl) and aluminum trichloride (AlCl3) (EMImCl-AlCl3, 1-1.1 in molar ratio) with or without LiAlCl4 is proposed. The hybrid ion battery delivers an initial high capacity of 160 mA h g(-1) at a current rate of C/5. It also shows good rate capability and cycling performance.

  3. Nanocrystalline porous TiO2 electrode with ionic liquid impregnated solid polymer electrolyte for dye sensitized solar cells.

    Science.gov (United States)

    Singh, Pramod K; Kim, Kang-Wook; Kim, Ki-Il; Park, Nam-Gyu; Rhee, Hee-Woo

    2008-10-01

    This communication reports the detailed fabrication of electrodes and solid polymer electrolyte with ionic liquid (IL) as an electrolyte for dye sensitized solar cell (DSSC). Thick porous TiO2 film has been obtained by spreading and sintering TiO2 colloidal paste using "doctor blade" and characterized by SEM, TEM and XRD. The polymer electrolyte was PEO:KI/I2 incorporated with 1-ethyl 3-methylimidazolium thiocyanate (EMImSCN) as IL. Dispersal of IL in the polymer electrolyte improved the ionic conductivity and cell efficiency.

  4. The scaled-charge additive force field for amino acid based ionic liquids

    DEFF Research Database (Denmark)

    Fileti, E. E.; Chaban, V. V.

    2014-01-01

    Ionic liquids (ILs) constitute an emerging research field. New ILs involve more and more organic and inorganic ions. Amino acid based ILs (AAILs) represent a specific interest due to their evolutional connection to proteins. We report a new non-polarizable force field (FF) for the eight AAILs...... comprising 1-ethyl-3-methylimidazolium cation and amino acid anions. The anions were obtained via deprotonation of carboxyl group. Specific cation-anion non-covalent interactions were taken into account by computing electrostatic potential for ion pairs. The van der Waals interactions were adopted from...

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

    Directory of Open Access Journals (Sweden)

    Mohammad Tariq

    2013-03-01

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

  6. Multi-scale modelling of supercapacitors: From molecular simulations to a transmission line model

    Science.gov (United States)

    Pean, C.; Rotenberg, B.; Simon, P.; Salanne, M.

    2016-09-01

    We perform molecular dynamics simulations of a typical nanoporous-carbon based supercapacitor. The organic electrolyte consists in 1-ethyl-3-methylimidazolium and hexafluorophosphate ions dissolved in acetonitrile. We simulate systems at equilibrium, for various applied voltages. This allows us to determine the relevant thermodynamic (capacitance) and transport (in-pore resistivities) properties. These quantities are then injected in a transmission line model for testing its ability to predict the charging properties of the device. The results from this macroscopic model are in good agreement with non-equilibrium molecular dynamics simulations, which validates its use for interpreting electrochemical impedance experiments.

  7. Direct electroplating of copper on tantalum from ionic liquids in high vacuum: origin of the tantalum oxide layer.

    Science.gov (United States)

    Schaltin, Stijn; D'Urzo, Lucia; Zhao, Qiang; Vantomme, André; Plank, Harald; Kothleitner, Gerald; Gspan, Christian; Binnemans, Koen; Fransaer, Jan

    2012-10-21

    In this paper, it is shown that high vacuum conditions are not sufficient to completely remove water and oxygen from the ionic liquid 1-ethyl-3-methylimidazolium chloride. Complete removal of water demands heating above 150 °C under reduced pressure, as proven by Nuclear Reaction Analysis (NRA). Dissolved oxygen gas can only be removed by the use of an oxygen scavenger such as hydroquinone, despite the fact that calculations show that oxygen should be removed completely by the applied vacuum conditions. After applying a strict drying procedure and scavenging of molecular oxygen, it was possible to deposit copper directly on tantalum without the presence of an intervening oxide layer.

  8. Promotion of Ionic Liquid to Dimethyl Carbonate Synthesis from Methanol and Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    CAI,Qing-Hai(蔡清海); ZHANG,Li(张丽); SHAN,Yong-Kui(单永奎); HE,Ming-Yuan(何鸣元)

    2004-01-01

    Promotion of ionic liquid,1-ethyl-3-methylimidazolium bromide (emimBr),to the synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide in the presence of potassium carbonate and less amount of methyl iodide under mild conditions was investigated.The results showed that the high selectivity and raised yield of DMC was achieved due to the addition of emimBr in the reaction system.And effect of several reaction conditions such as temperature,pressure and amount of emimBr was discussed.

  9. Synthesis of Dimethyl Carbonate from Methanol and Carbon Dioxide Catalyzed by Potassium Hydroxide under Mild Conditions

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide using potassium hydroxide as catalyst in the presence of CH3I and the effect of ionic liquid on the reaction were investigated. The results showed that KOH is an effective catalyst; the high selectivity and raised yield of DMC formation under mild conditions were achieved. However,the addition of the ionic liquid, 1-ethyl-3-methylimidazolium bromide (emimBr), can evidently accelerate the conversion of methanol and yield of the product.

  10. Cellulose hydrolysis by immobilized Trichoderma reesei cellulase.

    Science.gov (United States)

    Jones, Paetrice O; Vasudevan, Palligarnai T

    2010-01-01

    Cellulose hydrolysis by immobilized Trichoderma reesei cellulase in the presence of a low viscosity ionic liquid, 1-ethyl-3-methylimidazolium diethyl phosphate (EMIM-DEP), was investigated. Preparation of the carrier-free immobilized cellulase was optimized with respect to concentration of the cross-linker and the type of precipitant. The addition of 2% (v/v) EMIM-DEP during hydrolysis gave an initial reaction rate 2.7 times higher than the hydrolysis rate with no ionic liquid. The initial yield after 2 h was 0.7 g glucose/g cellulose, and the carrier-free immobilized cellulase (CFIC) was effectively re-used five times.

  11. Optical absorption and fluorescence studies on imidazolium ionic liquids comprising the bis(trifluoromethanesulphonyl)imide anion

    Indian Academy of Sciences (India)

    Aniruddha Paul; Anunay Samanta

    2006-07-01

    Optical absorption and fluorescence behaviour of two rigorously purified imidazolium ionic liquids, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide are studied in the neat condition and in solution. Non-negligible absorption in the UV region with a long tail extending into the visible region is the main feature of the absorption. Excitation wavelength-dependent two-component fluorescence characterizes the emission behaviour of these liquids. That ion association gives rise to the long absorption tail and shifting fluorescence maximum, which appears to be common to most of the imidazolium ionic liquids, is evident from the effect of the conventional solvents.

  12. Influence of the crystalline structure of cellulose on the production of ethanol from lignocellulose biomass

    Science.gov (United States)

    Smuga-Kogut, Małgorzata; Zgórska, Kazimiera; Szymanowska-Powałowska, Daria

    2016-01-01

    In recent years, much attention has been devoted to the possibility of using lignocellulosic biomass for energy. Bioethanol is a promising substitute for conventional fossil fuels and can be produced from straw and wood biomass. Therefore, the aim of this paper was to investigate the effect of 1-ethyl-3-methylimidazolium pretreatment on the structure of cellulose and the acquisition of reducing sugars and bioethanol from cellulosic materials. Material used in the study was rye straw and microcrystalline cellulose subjected to ionic liquid 1-ethyl-3-methylimidazolium pretreatment. The morphology of cellulose fibres in rye straw and microcrystalline cellulose was imaged prior to and after ionic liquid pretreatment. Solutions of ionic liquid-treated and untreated cellulosic materials were subjected to enzymatic hydrolysis in order to obtain reducing sugars, which constituted a substrate for alcoholic fermentation. An influence of the ionic liquid on the cellulose structure, accumulation of reducing sugars in the process of hydrolysis of this material, and an increase in ethanol amount after fermentation was observed. The ionic liquid did not affect cellulolytic enzymes negatively and did not inhibit yeast activity. The amount of reducing sugars and ethyl alcohol was higher in samples purified with 1-ethyl-3-methy-limidazolium acetate. A change in the supramolecular structure of cellulose induced by the ionic liquid was also observed.

  13. Fabrication and Characterization of Regenerated Cellulose Films Using Different Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Jin-Hui Pang

    2014-01-01

    Full Text Available The demand for substitution of fossil-based materials by renewable bio-based materials is increasing with the fossil resources reduction and its negative impacts on the environment. In this study, environmentally friendly regenerated cellulose films were successfully prepared using 1-allyl-3-methylimidazolium chloride (AmimCl, 1-butyl-3-methylimidazolium chloride (BmimCl, 1-ethyl-3-methylimidazolium chloride (EmimCl, and 1-ethyl-3-methylimidazolium acetate (EmimAc as solvents, respectively. The results of morphology from scanning electron microscopy (SEM and atomic force microscopy (AFM showed that all the cellulose films possessed smooth, highly uniform, and dense surface. The solid-state cross-polarization/magic angle spinning (CP/MAS 13C NMR spectra and X-ray diffraction (XRD corroborated that the transition from cellulose I to II had occurred after preparation. Moreover, it was shown that the ionic liquid EmimAc possessed much stronger dissolubility for cellulose as compared with other ionic liquids and the cellulose film regenerated from EmimCl exhibited the most excellent tensile strength (119 Mpa. The notable properties of regenerated cellulose films are promising for applications in transparent biodegradable packaging and agricultural purpose as a substitute for PP and PE.

  14. The Influence of Anion Shape on the Electrical Double Layer Microstructure and Capacitance of Ionic Liquids-Based Supercapacitors by Molecular Simulations

    Directory of Open Access Journals (Sweden)

    Ming Chen

    2017-02-01

    Full Text Available Room-temperature ionic liquids (RTILs are an emerging class of electrolytes for supercapacitors. In this work, we investigate the effects of different supercapacitor models and anion shape on the electrical double layers (EDLs of two different RTILs: 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonylimide ([Emim][Tf2N] and 1-ethyl-3-methylimidazolium 2-(cyanopyrrolide ([Emim][CNPyr] by molecular dynamics (MD simulation. The EDL microstructure is represented by number densities of cations and anions, and the potential drop near neutral and charged electrodes reveal that the supercapacitor model with a single electrode has the same EDL structure as the model with two opposite electrodes. Nevertheless, the employment of the one-electrode model without tuning the bulk density of RTILs is more time-saving in contrast to the two-electrode one. With the one-electrode model, our simulation demonstrated that the shapes of anions significantly imposed effects on the microstructure of EDLs. The EDL differential capacitance vs. potential (C-V curves of [Emim][CNPyr] electrolyte exhibit higher differential capacitance at positive potentials. The modeling study provides microscopic insight into the EDLs structure of RTILs with different anion shapes.

  15. Electrochemical behavior of PEDOT/Lignin in Ionic Liquid Electrolytes: Suitable Cathode/Electrolyte System for Sodium Batteries.

    Science.gov (United States)

    Casado, Nerea; Hilder, Matthias; Pozo-Gonzalo, Cristina; Forsyth, Maria; Mecerreyes, David

    2017-02-15

    Biomass derived polymers, such as lignin, contain redox quinone/hydroquinone redox moieties that can be used to store charge. Composites based on the biopolymer lignin and several conjugated polymers have shown good charge storage properties. However, their performance has been just studied in acidic aqueous media limiting the applications mainly to supercapacitors. Here we show that PEDOT/Lignin biopolymers are electroactive in aprotic ionic liquids and we move a step further by assembling sodium full cell batteries using PEDOT/Lignin as electrode material and ionic liquid electrolytes. Thus, the electrochemical activity and cycling of PEDOT/Lignin electrodes is investigated in 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BMPyrTFSI), 1-butyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide (BMPyrFSI), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMImTFSI) and 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMImFSI) ionic liquid electrolytes. The effects of water and sodium salt addition to the ionic liquids are investigated in order to obtain optimum electrolyte systems for sodium batteries. Finally, sodium batteries based on PEDOT/Lignin cathode with imidazolium based ionic liquid electrolyte showed higher capacity values than pyrrolidinium ones, reaching 70 mAhg-1. Our results demonstrate that PEDOT/Lignin composites can serve as low cost and sustainable cathode materials for sodium batteries.

  16. Separation of Guanine and Hypoxanthine with Some Ionic Liquids in RP-HPLC

    Directory of Open Access Journals (Sweden)

    J. Zheng

    2006-01-01

    Full Text Available In this paper, guanine and hypoxanthine were separated with four different ionic liquids as additives for the mobile phase using reversed phase high performance liquid chromatography (RP-HPLC. The ionic liquids, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4], 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIm][BF4], 1-ethyl-3-methylimidazolium methylsulfate ([EMIm][MS] and 1-octyl-3-methylimidazolium methylsulfate ([OMIm][MS] were used. Guanine and hypoxanthine couldn’t be separated with many different kinds of unadjusted mobile phase, such as aqueous-methanol, aqueous-acetonitrile, etc. In this reason, present study introduced the ionic liquid for separation of guanine and hypoxanthine as an eluent modifier. And the effects of length of alkyl on the imidazolium ring and its counterion, the concentrations of ionic liquid on the retention factor and effect of pH of mobile phase on retention factor of solutes were investigated also. As a result, guanine and hypoxanthine were separated with the mobile phase including ionic liquid and the excellent separations of these sorbats were achieved using 2.0 mM Lˉ1 [OMIm][MS] as the eluent modifier.

  17. Comparison Study of Different Ionic Liquid Pretreatments in Maximizing Total Reducing Sugars Recovery

    Directory of Open Access Journals (Sweden)

    Kiat Moon Lee

    2014-01-01

    Full Text Available A process scheme combining the most suitable ionic liquid pretreatment, followed by solid acid and enzymatic saccharification was used to maximize the reducing sugars recovery from sago waste. Three types of ionic liquids, i.e. 1-butyl-3-methylimidazolium chloride ([BMIM]Cl, 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc] and 1-ethyl-3-methylimidazolium diethyl phosphate ([EMIM][(EtO2PO2] were evaluated based on their performance in terms of the total reducing sugars recovery, chemical cost, and pretreatment energy requirement. The results showed that all the ionic liquids assisted the saccharification processes by dissolving and depolymerizing the carbohydrates of the sago waste into shorter chain soluble oligosaccharides, as well as disrupting the biomass structure to produce an amorphous pretreated solid residue. The solid acid saccharifications of the prehydrolysates obtained from the [BMIM]Cl pretreatment gave the highest reducing sugars recovery (61-63% irrespective of the solid acid catalyst employed. On the other hand, enzymatic saccharification of [EMIM][OAc] pretreated solid residues showed the highest reducing sugars recovery (29%. A maximum recovery of 90% reducing sugars was achieved via incorporation of the ionic liquid pretreatment, solid acid and enzymatic saccharifications using [BMIM]Cl, Amberlyst 15 (A15 and Trichoderma viride cellulase respectively. This study suggests that the combined sequential process can maximize the reducing sugars recovery from sago waste effectively.

  18. Molecular Dynamics Study of Ionic Liquid Film Based on [emim][Tf2N] and [emim][TfO] Adsorbed on Highly Oriented Pyrolytic Graphite

    Institute of Scientific and Technical Information of China (English)

    XUE Xiang-gui; ZHAO Li; L(U) Zhong-yuan; QIAN Hu-iun

    2013-01-01

    Molecular dynamics simulation was used to study the ionic liquid(IL) crystalline film based on 1-ethyl-3-methylimidazolium bis[trifluoromethylsulfonyl]imide([emim][Tf2N]) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate([emim][TfO]) on the graphite surface.Our results show that the cations are parallelly dis-tributed to the surface in the l/2 monolayer(ML) crystalline film.The [Tf2N] anions are parallel to the surface with the oxygen atoms at the bottom,whereas the [TfO] anions are perpendicularly distributed to the surface also with the oxygen atoms at the bottom in the 1/2 ML crystalline film.It has been found that the IL-vapor interface strongly influences the arrangement of ions at the interface.The anions in the top layer with the oxygen atoms outmost turn over to make themselves with the F atoms outmost so as to form C-H...O hydrogen bonds with the cations.The calculated orientational ordering shows that in the outmost layer at the IL-vapor interface,the cation rings present either parallel or perpendicular to the surface at 350 K.

  19. Halogen-Free Phosphonate Ionic Liquids as Precursors of Abrasion Resistant Surface Layers on AZ31B Magnesium Alloy

    Directory of Open Access Journals (Sweden)

    Tulia Espinosa

    2015-01-01

    Full Text Available Surface coatings formed by immersion in the ionic liquids (ILs 1,3-dimethylimidazolium methylphosphonate (LMP101, 1-ethyl-3-methylimidazolium methylphosphonate (LMP102 and 1-ethyl-3-methylimidazolium ethylphosphonate (LEP102 on magnesium alloy AZ31B at 50 °C have been studied. The purpose of increasing the temperature was to reduce the immersion time, from 14 days at room temperature, to 48 hours at 50 °C. The abrasion resistance of the coated alloy was studied by microscratching under progressively increasing load, and compared with that of the uncoated material. The order of abrasion resistance as a function of the IL is LEP102 > LMP101 > LMP102, which is in agreement with the order obtained for the coatings grown at room temperature. The maximum reduction in penetration depth with respect to the uncovered alloy, of a 44.5%, is obtained for the sample treated with the ethylphosphonate LEP102. However, this reduction is lower than that obtained when the coating is grown at room temperature. This is attributed to the increased thickness and lower adhesion of the coatings obtained at 50 °C, particularly those obtained from methylphosphonate ionic liquids. The results are discussed from SEM-EDX and profilometry.

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

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Ning [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Xu, Feng [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Sathitsuksanoh, Noppadon [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Thompson, Vicki S. [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Cafferty, Kara [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Li, Chenlin [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Tanjore, Deepti [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Narani, Akash [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Pray, Todd R. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Simmons, Blake A. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Singh, Seema [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Sandia National Laboratories (SNL-CA), Livermore, CA (United States)

    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.

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

    Science.gov (United States)

    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.

  2. Investigation of polymer electrolyte based on agar and ionic liquids

    Directory of Open Access Journals (Sweden)

    M. M. Silva

    2012-12-01

    Full Text Available The possibility to use natural polymer as ionic conducting matrix was investigated in this study. Samples of agarbased electrolytes with different ionic liquids were prepared and characterized by physical and chemical analyses. The ionic liquids used in this work were 1-ethyl-3-methylimidazolium ethylsulfate, [C2mim][C2SO4], 1-ethyl-3-methylimidazolium acetate, [C2mim][OAc] and trimethyl-ethanolammonium acetate, [Ch][OAc]. Samples of solvent-free electrolytes were prepared and characterized by ionic conductivity measurements, thermal analysis, electrochemical stability, X-ray diffraction, scanning electron microscopy and Fourier Transform infrared spectroscopy. Electrolyte samples are thermally stable up to approximately 190°C. All the materials synthesized are semicrystalline. The electrochemical stability domain of all samples is about 2.0 V versus Li/Li+. The preliminary studies carried out with electrochromic devices (ECDs incorporating optimized compositions have confirmed that these materials may perform as satisfactory multifunctional component layers in the field of ‘smart windows’, as well as ECD-based devices.

  3. Phase equilibria of haloalkanes dissolved in ethylsulfate- or ethylsulfonate-based ionic liquids.

    Science.gov (United States)

    Deive, Francisco J; Rodríguez, Ana; Pereiro, Ana B; Shimizu, Karina; Forte, Paulo A S; Romão, Carlos C; Canongia Lopes, José N; Esperança, José M S S; Rebelo, Luís P N

    2010-06-03

    The temperature-composition phase diagrams of 40 binary mixtures composed of a haloalkane dissolved in either 1-ethyl-3-methylimidazolium ethylsulfate or 1-ethyl-3-methylimidazolium ethylsulfonate were measured from ambient temperature to the boiling point temperature of the solute. The coexistence curves corresponding to liquid-liquid equilibria (LLE) boundaries were visually determined and the experimental results have been correlated using either the nonrandom two-liquid (NRTL) model or a set of empirical equations capable of describing the corresponding upper critical solution temperatures (UCSTs) loci. The different types of LLE behavior were discussed in terms of the type of ionic liquid solvent, the alkyl-chain length of the solute, and the type and pattern of halogen substitution present in the haloalkane. Auxiliary simulation data (obtained by ab initio or by molecular dynamics methods) were used to corroborate some of the experimental findings. Also, they correlate in a semiquantitative way the observed LLE behavior with the dipole moments of the different solutes.

  4. Phase equilibria in ionic liquid-aromatic compound mixtures, including benzene fluorination effects.

    Science.gov (United States)

    Blesic, Marijana; Lopes, José N Canongia; Pádua, Agílio A H; Shimizu, Karina; Gomes, Margarida F Costa; Rebelo, Luís Paulo N

    2009-05-28

    This work extends the scope of previous studies on the phase behavior of mixtures of ionic liquids with benzenes or its derivatives by determining the solid-liquid and liquid-liquid phase diagrams of mixtures containing an ionic liquid and a fluorinated benzene. The systems studied include 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide plus hexafluorobenzene or 1,3,5-trifluorobenzene and 1-ethyl-3-methylimidazolium triflate or N-ethyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide plus benzene. The phase diagrams exhibit different kinds of solid-liquid behavior: the (usual) occurrence of eutectic points; the (not-so-usual) presence of congruent melting points and the corresponding formation of inclusion crystals; or the observation of different ionic liquid crystalline phases (polymorphism). These different types of behavior can be controlled by temperature annealing during crystallization or by the nature of the aromatic compound and can be interpreted, at a molecular level, taking into account the structure of the crystals or liquid mixtures, together with the unique characteristics of ionic liquids, namely the dual nature of their interactions with aromatic compounds.

  5. Photoinduced Bimolecular Electron Transfer from Cyano Anions in Ionic Liquids.

    Science.gov (United States)

    Wu, Boning; Liang, Min; Maroncelli, Mark; Castner, Edward W

    2015-11-19

    Ionic liquids with electron-donating anions are used to investigate rates and mechanisms of photoinduced bimolecular electron transfer to the photoexcited acceptor 9,10-dicyanoanthracene (9,10-DCNA). The set of five cyano anion ILs studied comprises the 1-ethyl-3-methylimidazolium cation paired with each of these five anions: selenocyanate, thiocyanate, dicyanamide, tricyanomethanide, and tetracyanoborate. Measurements with these anions dilute in acetonitrile and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide show that the selenocyanate and tricyanomethanide anions are strong quenchers of the 9,10-DCNA fluorescence, thiocyanate is a moderately strong quencher, dicyanamide is a weak quencher, and no quenching is observed for tetracyanoborate. Quenching rates are obtained from both time-resolved fluorescence transients and time-integrated spectra. Application of a Smoluchowski diffusion-and-reaction model showed that the complex kinetics observed can be fit using only two adjustable parameters, D and V0, where D is the relative diffusion coefficient between donor and acceptor and V0 is the value of the electronic coupling at donor-acceptor contact.

  6. CO2 capture in ionic liquid 1-alkyl-3-methylimidazolium acetate: a concerted mechanism without carbene.

    Science.gov (United States)

    Yan, Fangyong; Dhumal, Nilesh R; Kim, Hyung J

    2017-01-04

    Ionic liquids (ILs) provide a promising medium for CO2 capture. Recently, the family of ILs comprising imidazolium-based cations and acetate anions, such as 1-ethyl-3-methylimidazolium acetate (EMI(+)OAc(-)), has been found to react with CO2 and form carboxylate compounds. N-Heterocyclic carbene (NHC) is widely assumed to be responsible by directly reacting with CO2 though NHC has not been detected in these ILs. Herein, a computational analysis of CO2 capture in EMI(+)OAc(-) is presented. Quantum chemistry calculations predict that NHC is unstable in a polar environment, suggesting that NHC is not formed in EMI(+)OAc(-). Ab initio molecular dynamics simulations indicate that an EMI(+) ion "activated" by the approach of a CO2 molecule can donate its acidic proton to a neighboring OAc(-) anion and form a carboxylate compound with the CO2 molecule. Analysis of this termolecular process indicates that the EMI(+)-to-OAc(-) proton transfer and the formation of 1-ethyl-3-methylimidazolium-2-carboxylate occur essentially concurrently. Based on these findings, a novel concerted mechanism that does not involve NHC is proposed for CO2 capture.

  7. Ionic Liquid based polymer electrolytes for electrochemical sensors

    Directory of Open Access Journals (Sweden)

    Jakub Altšmíd

    2015-09-01

    Full Text Available Amperometric NO2 printed sensor with a new type of solid polymer electrolyte and a carbon working electrode has been developed. The electrolytes based on 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonylimide [EMIM][N(Tf2], 1-butyl-3-methylimidazolium trifluoromethanesulfonate [BMIM][CF3SO3] and 1-ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF4] ionic liquids were immobilized in poly(vinylidene fluoride matrix [PVDF]. The analyte, gaseous nitrogen dioxide, was detected by reduction at -500 mV vs. platinum pseudoreference electrode. The sensors showed a linear behavior in the whole tested range, i.e., 0 - 5 ppm and their sensitivities were in order of 0.3 x∙10-6 A/ppm. The sensor sensitivity was influenced by the electric conductivity of printing formulation; the higher the conductivity, the higher the sensor sensitivity. The rise/recovery times were in order of tens of seconds. The use of  screen printing technology and platinum pseudoreference electrode simplify the sensor fabrication and it does not have any negative effect on the sensor stability.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7371

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

    Energy Technology Data Exchange (ETDEWEB)

    Courtney, Daniel G., E-mail: dcourtney@alum.mit.edu; Shea, Herbert [Ecole Polytechnique Federale de Lausanne (EPFL), Microsystems for Space Technologies Laboratory (LMTS), Neuchatel CH-2002 (Switzerland)

    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.

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

    Science.gov (United States)

    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%.

  10. Ionic Liquid and HP-β-CD Modified Capillary Zone Electrophoresis to Separate Hyperoside, Luteolin and Chlorogenic Acid

    Institute of Scientific and Technical Information of China (English)

    Yue Ling WANG; Zhong Bo HU; Zhuo Bin YUAN

    2006-01-01

    Ionic liquid (1-ethyl-3-methylimidazolium tetrafluoroborate, 1E-3MI-TFB) and HP-β-CD as modifier was added to the buffer to separate hyperoside, luteolin and chlorogenic acid.Experiments explored the effect of concentration of 1E-3MI-TFB and HP-β-CD on separation.The results indicated that 1.0 mmol/L HP-β-CD and 1‰ (v/v) 1E-3MI-TFB added to the buffer simultaneous y could achieve a good compromise of resolution and analysis time. Capillary experiments and UV spectra indicated that there was interaction between 1E-3MI-TFB and analytes.

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

    Science.gov (United States)

    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

    2015-12-30

    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.

  12. STRUCTURAL CHANGES EVIDENCED BY FTIR SPECTROSCOPY IN CELLULOSE MATERIALS AFTER PRE-TREATMENT WITH IONIC LIQUID AND ENZYMATIC HYDROLYSIS

    Directory of Open Access Journals (Sweden)

    Iuliana Spiridon

    2011-02-01

    Full Text Available Attempts were made to enhance the hydrolysis of Asclepias syriaca (As seed floss and poplar seed floss (PSF by cellulase after pre-treatment with ionic liquids. Two ionic liquids, namely 1-butyl-3-methylimidazolium chloride [BMIM]Cl and 1-ethyl-3-methylimidazolium tetrachloroaluminate [EMIM]Cl-AlCl3, were used. In comparison with conventional cellulose pretreatment processes, the ionic liquids were used under a milder condition corresponding to the optimum activity of cellulase. Hydrolysis kinetics of the IL-treated cellulose materials was significantly enhanced. The initial hydrolysis rates for IL-treated cellulose materials were greater than those of non-treated ones. The structural modifications of hydrolyzed cellulose materials were analyzed using FTIR spectroscopy.

  13. Efficient Formation of Multicomponent Ion Gels by Stepwise Self-Assembly of Thermoresponsive ABC Triblock Terpolymers

    Science.gov (United States)

    Danielsen, Scott; Zhou, Can; Lodge, Timothy

    2013-03-01

    The gelation behavior of a poly(ethylene-alt-propylene)- b-poly(ethylene oxide)- b-poly(N-isopropyl acrylamide) (PON) triblock terpolymer in room-temperature ionic liquids, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM] [TFSI]), has been studied by rheology over the concentration range 1-10 wt.%. PON terpolymers have proven better gelation efficiency and mechanical properties (modulus) in hydrogels. Physical ion gels from PON terpolymers in [BMIM][BF4] and [EMIM][TFSI] have been studied to determine improvements in gelation efficiency and mechanical properties (modulus) for triblock terpolymers. A two-compartment micellar network is believed to result from the stepwise gelation of PON terpolymers involving micellization at elevated temperatures and gelation at lower temperatures.

  14. On the Synthesis of Molybdenum Nanoparticles under Reducing Conditions in Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Ayi A. Ayi

    2015-01-01

    Full Text Available We report on attempts to synthesize Mo nanoparticles under reducing conditions in ionic liquids (ILs. Ionic liquids were based on the 1-ethyl-3-methylimidazolium or 1-butyl-3-methylimidazolium (Emim and Bmim, resp. cations and the dicyanamide N(CN2, triflate (OTf, bis(trifluoromethylsulfonylimide-(NTf2, tetrafluoroborate (BF4, ethyl sulfate (ES, and methylsulfonate (MS anions. (NH46Mo7O24∗4H2O and NaBH4 were reacted in a set of imidazolium ionic liquids (ILs at 180°C to evaluate the potential of the ILs for stabilization of metallic Mo nanoparticles. XRD and TEM reveal a strong influence of the IL anion on the particle sizes, shapes, and crystal structures. The influence of the IL cation and the reaction temperature is much less pronounced.

  15. Green synthesized nickel nanoparticles modified electrode in ionic liquid medium and its application towards determination of biomolecules.

    Science.gov (United States)

    Babu, Rajendran Suresh; Prabhu, Pandurangan; Narayanan, Sangilimuthu Sriman

    2013-06-15

    An air and moisture stable ionic liquid 1-ethyl-3-methylimidazolium ethyl sulfate (EMIMES) was used as an electrolyte for electropolymerization of L-cysteine followed by electrodeposition of nickel nanoparticles (NiNP) on paraffin wax impregnated graphite electrode (PIGE). The electrodeposited NiNP modified electrode showed good redox activity and stability in 0.1M KOH solution. The modified electrode has been characterized using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The modified electrode was examined for electrocatalytic oxidation of some compounds of biological and clinical importance such as vitamin B6, L-tyrosine, L-tryptophan, vanillin, glucose and hydrogen peroxide by cyclic voltammetry to demonstrate the electrocatalytic activity of the electrodeposited NiNPs.

  16. Symmetry Breaking in Chiral Ionic Liquids Evidenced by Vibrational Optical Activity.

    Science.gov (United States)

    Oulevey, Patric; Luber, Sandra; Varnholt, Birte; Bürgi, Thomas

    2016-09-19

    Ionic liquids (ILs) are receiving increasing interest for their use in synthetic laboratories and industry. Being composed of charged entities, they show a complex and widely unexplored dynamic behavior. Chiral ionic liquids (CILs) have a high potential as solvents for use in asymmetric synthesis. Chiroptical methods, owing to their sensitivity towards molecular conformation, offer unique possibilities to study the structure of these chiral ionic liquids. Raman optical activity proved particularly useful to study ionic liquids composed of amino acids and the achiral 1-ethyl-3-methylimidazolium counterion. We could substantiate, supported by selected theoretical methods, that the achiral counterion adopts an overall chiral conformation in the presence of chiral amino acid ions. These findings suggest that in the design of chiral ionic liquids for asymmetric synthesis, the structure of the achiral counter ion also has to be carefully considered.

  17. Corrosion Inhibition of Cast Iron in Arabian Gulf Seawater by Two Different Ionic Liquids

    Directory of Open Access Journals (Sweden)

    El-Sayed M. Sherif

    2015-06-01

    Full Text Available In this paper we report on the corrosion inhibition of cast iron in Arabian Gulf seawater by two different ionic liquids namely, 1-ethyl-3-methylimidazolium chloride ([EMIm]Cl and 1-butyl-1-methylpyrrolidinium chloride ([Py1,4]Cl. The inhibiting influence of the employed ionic liquids was investigated by weight loss, open circuit potential electrochemical impedance spectroscopy, and cyclic potentiodynamic polarization. The results show the corrosion inhibition impact of the employed ionic liquids (ILs. Compared with [Py1,4]Cl, [EMIm]Cl shows a higher inhibition efficiency at a short immersion time, for the examined ILs concentrations. However, [Py1,4]Cl exhibits a higher efficiency upon increasing the immersion time indicating the persistence of the inhibiting influence. The corrosion inhibition of the employed ionic liquids is attributed to the adsorption of the cations of the ionic liquids onto the surface of cast iron forming a corrosion barrier.

  18. Molecular ions of ionic liquids in the gas phase.

    Science.gov (United States)

    Gross, Jürgen H

    2008-09-01

    Ionic liquids form neutral ion pairs (CA) upon evaporation. The softness of the gas-phase ionization of field ionization has been used to generate "molecular ions," CA(+*), of ionic liquids, most probably by neutralization of the anion. In detail, 1-ethyl-3-methylimidazolium-thiocyanate, [C(6)H(11)N(2)](+) [SCN](-), 1-butyl-3-methylimidazolium-tricyanomethide, [C(8)H(15)N(2)](+) [C(4)N(3)](-), N-butyl-3-methylpyridinium-dicyanamide, [C(10)H(16)N](+) [C(2)N(3)](-), and 1-butyl-1-methylpyrrolidinium-bis[(trifluormethyl)sulfonyl]amide, [C(9)H(20)N](+) [C(2)F(6)NO(4)S(2)](-) were used. The assignment as CA(+*) ions, which has been confirmed by accurate mass measurements and misassignments due to thermal decomposition of the ionic liquids, has been ruled out by field desorption and electrospray ionization mass spectrometry of the residues.

  19. Direct reduction of carbon dioxide to formate in high-gas-capacity ionic liquids at post-transition-metal electrodes.

    Science.gov (United States)

    Watkins, John D; Bocarsly, Andrew B

    2014-01-01

    As an approach to combat the increasing emissions of carbon dioxide in the last 50 years, the sequestration of carbon dioxide gas in ionic liquids has become an attractive research area. Ionic liquids can be made that possess incredibly high molar absorption and specificity characteristics for carbon dioxide. Their high carbon dioxide solubility and specificity combined with their high inherent electrical conductivity also creates an ideal medium for the electrochemical reduction of carbon dioxide. Herein, a lesser studied ionic liquid, 1-ethyl-3-methylimidazolium trifluoroacetate, was used as both an effective carbon dioxide capture material and subsequently as an electrochemical matrix with water for the direct reduction of carbon dioxide into formate at indium, tin, and lead electrodes in good yield (ca. 3 mg h(-1) cm(-2)).

  20. Effects of solubility properties of solvents and biomass on biomass pretreatment.

    Science.gov (United States)

    Weerachanchai, Piyarat; Kwak, Sang Kyu; Lee, Jong-Min

    2014-10-01

    Hildebrand solubility parameters of biomasses and pretreatment solvents were examined by a method of intrinsic viscosity. This is to be used as basic information in selecting a suitable solvent for biomass pretreatment processes. The effects of mixing1-ethyl-3-methylimidazolium acetate (EMIM-AC) and different solvents, lignin content in a pretreatment solvent, and biomass type on the Hildebrand solubility parameter and thermodynamic properties were carried out and calculated in this work. The Hildebrand solubility parameters of the mixtures are according to those of organic solvents: δH[EMIM-AC/DMA]=25.07biomass compositions (microcrystalline cellulose, xylan and alkali lignin) and biomasses (cassava pulp residue and rice straw) vary in the ranges of 25.14-26.13. The increases of lignin content in the pretreatment solvents lead to the Hildebrand solubility parameter becoming closer to that of lignin.

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

    Directory of Open Access Journals (Sweden)

    Alsu A. Akhmetshina

    2015-12-01

    Full Text Available 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(trifluoromethylsulfonylimide ([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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Daniel F.; Urata, Chihiro; Masheder, Benjamin; Dunderdale, Gary J.; Hozumi, Atsushi, E-mail: a.hozumi@aist.go.jp [National Institute of Advanced Industrial Science and Technology (AIST), 2266-98, Anagahora, Shimo-Shidami, Moriyama-ku, Nagoya, Aichi 463-8560 (Japan); Yagihashi, Makoto [Nagoya Municipal Industrial Research Institute, Rokuban, Atsuta-ku, Nagoya 456-0058 (Japan)

    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.

  3. Microwave-Assisted Preparation of CdS Nanoparticles in a Halide-Free Ionic Liquid and Their Photocatalytic Activities

    Institute of Scientific and Technical Information of China (English)

    M. ESMAILI, A; HABIBI-YANGJEH

    2011-01-01

    A microwave-assisted (4-6 min) method was used for the preparation ofCdS nanoparticles in 1-ethyl-3-methylimidazolium ethyl sulfate, a halide-free room-temperature ionic liquid (RTIL). The samples were characterized by powder X-ray diffraction, energy dispersive X-ray spectroscopy, and scanning electron microscopy. Diffuse reflectance spectra showed a 1.33 eV blue shift relative to bulk CdS. The photocatalytic activities of the nanoparticles for photodegradation of methylene blue (MB) using UV and visible light were measured. The photodegradation of MB decreased with calcination temperature. First order rate constants for the reaction under visible and UV irradiations over the nanoparticles prepared in the RTIL rich media were 5.4 and 2.5 higher, respectively, than the sample prepared in water.

  4. Promoting Effect of Layered Titanium Phosphate on the Electrochemical and Photovoltaic Performance of Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Deng Changsheng

    2010-01-01

    Full Text Available Abstract We reported a composite electrolyte prepared by incorporating layered α-titanium phosphate (α-TiP into an iodide-based electrolyte using 1-ethyl-3-methylimidazolium tetrafluoroborate(EmimBF4 ionic liquid as solvent. The obtained composite electrolyte exhibited excellent electrochemical and photovoltaic properties compared to pure ionic liquid electrolyte. Both the diffusion coefficient of triiodide (I3 − in the electrolyte and the charge-transfer reaction at the electrode/electrolyte interface were improved markedly. The mechanism for the enhanced electrochemical properties of the composite electrolyte was discussed. The highest conversion efficiency of dye-sensitized solar cell (DSSC was obtained for the composite electrolyte containing 1wt% α-TiP, with an improvement of 58% in the conversion efficiency than the blank one, which offered a broad prospect for the fabrication of stable DSSCs with a high conversion efficiency.

  5. Vaporization behavior of tetraoctylphosphonium bis(2-ethylhexyl)phosphate ionic liquid

    Science.gov (United States)

    McMurray, J. W.; Zhou, Y.; Luo, H. M.; Qu, J.

    2017-01-01

    The equilibrium vapor pressures, pe, of the ionic liquid tetraoctylphosphonium bis(2-ethylhexyl)phosphate ([P8888][DEHP]) over the temperature range 409-495 K were determined for the first time using mass loss Knudsen effusion. The pe versus temperature relationship compares well to 1-methyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide ([C8mim][NTf2]) but is lower than that of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][NTf2]) when measured using the same technique. The discrepancies between the pe determined in this work for [C8mim][NTf2] and [C2mim][NTf2] with previous studies is discussed. The enthalpy and entropy of vaporization for all three fluids are estimated from the Clasius-Clapeyron relation.

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

    Science.gov (United States)

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

    2015-05-05

    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.

  7. Identification of Structural Motifs of Imidazolium Based Ionic Liquids from Jet-Cooled Infrared Spectroscopy.

    Science.gov (United States)

    Young, Justin W.; Booth, Ryan S.; Annesley, Christopher; Stearns, Jaime A.

    2016-06-01

    Highly variable and potentially revolutionary, ionic liquids (IL) are a class of molecules with potential for numerous Air Force applications such as satellite propulsion, but the complex nature of IL structure and intermolecular interactions makes it difficult to adequately predict structure-property relationships in order to make new IL-based technology a reality. For example, methylation of imidazolium ionic liquids leads to a substantial increase in viscosity but the underlying physical mechanism is not understood. In addition the role of hydrogen bonding in ILs, especially its relationship to macroscopic properties, is a matter of ongoing research. Here, structural motifs are identified from jet-cooled infrared spectra of different imidazolium based ionic liquids, such as 1-ethyl-3-methylimidazolium bis(trifluoromethyl-sulfonyl)imide. Measurements of the C-H stretches indicate three structural families present in the gas phase.

  8. Long-range magnetic ordering in magnetic ionic liquid: Emim[FeCl{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    De Pedro, I; Rojas, D P; Rodriguez Fernandez, J [CITIMAC, Facultad de Ciencias, Universidad de Cantabria, 39005 Santander (Spain); Albo, J; Luis, P; Irabien, A [Departamento de Ingenierioa Quimica y Quimica Inorganica, Universidad de Cantabria, 39005 Santander (Spain); Blanco, Jesus A, E-mail: rodrigufj@unican.e [Departamento de Fisica, Universidad de Oviedo, 33007 Oviedo (Spain)

    2010-07-28

    Up to now most of the magnetic ionic liquids containing tetrachloroferrate ion FeCl{sub 4} have evidenced a paramagnetic temperature dependence of the magnetic susceptibility, with only small deviations from the Curie law at low temperatures. However, we report on the physical properties of 1-ethyl-3-methylimidazolium tetrachloroferrate Emim[FeCl{sub 4}], that clearly shows a long-range antiferromagnetic ordering below the Neel temperature T{sub N{approx}}3.8 K. In addition, the field dependence of the magnetization measured at 2 K is characterized by a linear behaviour up to around 40 kOe, while above this field the magnetization becomes saturated with a value of 4.3 {mu}{sub B}/Fe, which is near the expected fully saturated value of 5 {mu}{sub B}/Fe for an Fe{sup 3+} ion.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Daniel F. Miranda

    2014-05-01

    Full Text Available 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-aminopropyltriethoxysilane. 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.

  11. Green hydrothermal synthesis and optical properties of γ-Gd2S3 nanoparticles

    Science.gov (United States)

    Khajuria, Sonika; Ladol, Jigmet; Sanotra, Sumit; Sheikh, Haq Nawaz

    2016-06-01

    Green synthesis of γ-Gd2S3 nanoparticles was carried out using low-temperature hydrothermal route in autoclave. A 1:1 mixture of ionic liquid 1-ethyl-3-methylimidazolium ethyl sulfate, ([EMIM][EtSO4]), and water was used as a solvent. Synthesized nanoparticles were characterized by x-ray powder diffraction (XRPD), scanning electron microscopy (SEM), UV-visible spectroscopy (UV-vis), particle size by dynamic light scattering (DLS) technique, and photoluminescence (PL) studies. XRPD suggests cubic Th3P4-type structure for obtained Gd2S3 nanoparticles. The size of synthesized nanoparticles is about 86 nm. Optical band gap for these nanoparticles estimated from electronic spectrum is 2.95 eV which shows blue shift from values reported for bulk Gd2S3 due to pronounced quantum mechanical effect. These nanoparticles show sharp emission peak at 385 nm and a broad shoulder at 475 nm when excited at 260 nm.

  12. Reactions of Lignin Model Compounds in Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-09-15

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

  13. Pretreatment of rice hulls by ionic liquid dissolution.

    Science.gov (United States)

    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.

  14. Addition of ammonia and/or oxygen to an ionic liquid for delignification of miscanthus.

    Science.gov (United States)

    Rodríguez, Héctor; Padmanabhan, Sasisanker; Poon, Geoffrey; Prausnitz, John M

    2011-09-01

    Ammonia and/or oxygen were used to enhance the delignification of miscanthus dissolved in 1-ethyl-3-methylimidazolium acetate at 140°C. After dissolution of the gas at 9 bar, water was added as antisolvent to regenerate the dissolved biomass. In a next step, an acetone/water mixture was used to remove carbohydrate-free lignin from the regenerated biomass. The lignin content in the final product was around 10%, much lower than the ca. 23% lignin content of the raw dry miscanthus. This lignin reduction is achieved without diminution of cellulose or of total carbohydrates recovered, relative to the recovery achieved with the ionic liquid pretreatment in contact with air or nitrogen.

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

    Science.gov (United States)

    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.

  16. Dissolution enthalpies of cellulose in ionic liquids.

    Science.gov (United States)

    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.

  17. A highly viscous imidazolium ionic liquid inside carbon nanotubes.

    Science.gov (United States)

    Ohba, Tomonori; Chaban, Vitaly V

    2014-06-12

    We report a combined experimental (X-ray diffraction) and theoretical (molecular dynamics, hybrid density functional theory) study of 1-ethyl-3-methylimidazolium chloride, [C2C1MIM][Cl], inside carbon nanotubes (CNTs). We show that despite its huge viscosity [C2C1MIM][Cl] readily penetrates into 1-3 nm wide CNTs at slightly elevated temperatures (323-363 K). Molecular simulations were used to assign atom-atom peaks. Experimental and simulated structures of RTIL inside CNT and in bulk phase are in good agreement. We emphasize a special role of the CNT-chloride interactions in the successful adsorption of [C2C1MIM][Cl] on the inner sidewalls of 1-3 nm carbon nanotubes.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

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

    Science.gov (United States)

    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.

  20. Comparison of different pretreatments for the production of bioethanol and biomethane from corn stover and switchgrass.

    Science.gov (United States)

    Papa, G; Rodriguez, S; George, A; Schievano, A; Orzi, V; Sale, K L; Singh, S; Adani, F; Simmons, B A

    2015-05-01

    In this study the efficiency of mild ionic liquid (IL) pretreatment and pressurized hot water (PHW) is evaluated and compared in terms of bioethanol and biomethane yields, with corn stover (CS) and switchgrass (SG) as model bioenergy crops. Both feedstocks pretreated with the IL 1-ethyl-3-methylimidazolium acetate [C2C1Im][OAc] at 100°C for 3h exhibited lower glucose yield that those treated with harsher pretreatment conditions previously used. Compared to PHW, IL pretreatment demonstrated higher bioethanol yields; moreover IL pretreatment enhanced biomethane production. Taking into consideration both bioethanol and biomethane productions, results indicated that when using IL pretreatment, the total energy produced per kg of total solids was higher compared to untreated biomasses. Specifically energy produced from CS and SG was +18.6% and +34.5% respectively, as compared to those obtained by hot water treatment, i.e. +2.3% and +23.4% for CS and SG, respectively.

  1. A comparative study of room temperature ionic liquids and their organic solvent mixtures near charged electrodes

    Science.gov (United States)

    Vatamanu, Jenel; Vatamanu, Mihaela; Borodin, Oleg; Bedrov, Dmitry

    2016-11-01

    The structural properties of electrolytes consisting of solutions of ionic liquids in a polar solvent at charged electrode surfaces are investigated using classical atomistic simulations. The studied electrolytes consisted of tetraethylammonium tetrafluoroborate (NEt4-BF4), 1-ethyl-3-methylimidazolium tetrafluoroborate (c2mim-BF4) and 1-octyl-3-methylimidazolium tetrafluoroborate (c8mim-BF4) salts dissolved in acetonitrile solvent. We discuss the influence of electrolyte concentration, chemical structure of the ionic salt, temperature, conducting versus semiconducting nature of the electrode, electrode geometry and surface roughness on the electric double layer structure and capacitance and compare these properties with those obtained for pure room temperature ionic liquids. We show that electrolytes consisting of solutions of ions can behave quite differently from pure ionic liquid electrolytes.

  2. A Highly Viscous Imidazolium Ionic Liquid inside Carbon Nanotubes

    DEFF Research Database (Denmark)

    Ohba, T.; Chaban, Vitaly V.

    2014-01-01

    We report a combined experimental (X-ray diffraction) and theoretical (molecular dynamics, hybrid density functional theory) study of 1-ethyl-3-methylimidazolium chloride, [C2C1MIM][Cl], inside carbon nanotubes (CNTs). We show that despite its huge viscosity [C2C1MIM][Cl] readily penetrates into 1......-3 nm wide CNTs at slightly elevated temperatures (323-363 K). Molecular simulations were used to assign atom-atom peaks. Experimental and simulated structures of RTIL inside CNT and in bulk phase are in good agreement. We emphasize a special role of the CNT-chloride interactions in the successful...... adsorption of [C2C1MIM][Cl] on the inner sidewalls of 1-3 nm carbon nanotubes....

  3. Development and characterization of poly(1-vinylpyrrolidone-co-vinyl acetate) copolymer based polymer electrolytes.

    Science.gov (United States)

    Sa'adun, Nurul Nadiah; Subramaniam, Ramesh; Kasi, Ramesh

    2014-01-01

    Gel polymer electrolytes (GPEs) are developed using poly(1-vinylpyrrolidone-co-vinyl acetate) [P(VP-co-VAc)] as the host polymer, lithium bis(trifluoromethane) sulfonimide [LiTFSI] as the lithium salt and ionic liquid, and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide [EMImTFSI] by using solution casting technique. The effect of ionic liquid on ionic conductivity is studied and the optimum ionic conductivity at room temperature is found to be 2.14 × 10(-6) S cm(-1) for sample containing 25 wt% of EMImTFSI. The temperature dependence of ionic conductivity from 303 K to 353 K exhibits Arrhenius plot behaviour. The thermal stability of the polymer electrolyte system is studied by using thermogravimetric analysis (TGA) while the structural and morphological properties of the polymer electrolyte is studied by using Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction analysis (XRD), respectively.

  4. Recyclability of an ionic liquid for biomass pretreatment.

    Science.gov (United States)

    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).

  5. Electrochemical quartz crystal microbalance (EQCM) study of ion dynamics in nanoporous carbons.

    Science.gov (United States)

    Tsai, Wan-Yu; Taberna, Pierre-Louis; Simon, Patrice

    2014-06-18

    Electrochemical quartz crystal microbalance (EQCM) and cyclic voltammetry (CV) measurements were used to characterize ion adsorption in carbide-derived carbon (CDC) with two different average pore sizes (1 and 0.65 nm), from neat and solvated 1-Ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMI-TFSI) electrolytes. From the electrode mass change in neat EMI-TFSI, it was shown that one net charge stored corresponds almost to one single ion at high polarization; in that case, no ion-pairing or charge screening by co-ions were observed. In 2 M EMI-TFSI in acetonitrile electrolyte, experimental solvation numbers were estimated for EMI(+) cation, showing a partial desolvation when cations were adsorbed in confined carbon pores. The extent of desolvation increased when decreasing the carbon pore size (from 1 down to 0.65 nm). The results also suggest that EMI(+) cation owns higher mobility than TFSI(-) anion in these electrolytes.

  6. Quasi-solid state polymer electrolytes for dye-sensitized solar cells. Effect of the electrolyte components variation on the triiodide ion diffusion properties and charge-transfer resistance at platinum electrode

    Energy Technology Data Exchange (ETDEWEB)

    Nazmutdinova, G.; Sensfuss, S.; Schroedner, M. [Thuringian Institute for Textile and Plastics Research, Breitscheidstrasse 97, 07407 Rudolstadt (Germany); Hinsch, A. [Fraunhofer Institute for Solar Energy Systems, Heidenhofstrasse 2, 79110 Freiburg (Germany); Sastrawan, R. [Freiburg Materials Research Center FMF, Stefan-Meier-Street 21, 79104 Freiburg (Germany); Gerhard, D.; Himmler, S.; Wasserscheid, P. [Friedrich-Alexander-University, Egerlandstrasse 3, 91058 Erlangen (Germany)

    2006-11-30

    Quasi-solid state polymer electrolytes have been prepared from poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) as gelator for 1-ethyl-3-methylimidazolium based ionic liquids (with anions like trifluoromethanesulfonate [EMIM][TfO], bis(trifluoromethanesulfonyl)imide [EMIM][Tf{sub 2}N]) and polyacrylonitrile (PAN) for gelation of 1-ethyl-3-methylimidazolium dicyanamide [EMIM][DCA] as well as I{sup -}/I{sub 3}{sup -} as the redox couple. All electrolytes exhibit high ionic conductivity in the range of 10{sup -3} S/cm. The effect of gelation, redox couple concentration, I{sup -}/I{sub 3}{sup -} ratio, choice of cations and additives on the triiodide diffusion and charge-transfer resistance of the platinum/electrolyte interface (R{sub ct}) were studied. The apparent diffusion coefficient of triiodide ion (D(I{sub 3}{sup -})) at various iodide/triiodide ratios in liquid and gelified electrolytes has been calculated from measurements of the diffusion limited current (I{sub lim}) in electrochemical cell resembling the set-up of a dye-sensitized solar cell. The charge-transfer resistance of the platinum/electrolyte interface as well as the capacitance of the electrical double layer (C{sub dl}) have been calculated from impedance measurements. Electrolytes with reduced content of polymer (2.5 wt.%) were doped with Al{sub 2}O{sub 3} particles of different sizes (50 nm, 300 nm, 1 {mu}m). The dispersion of the particles proceeds by speedy stirring of the hot electrolyte and the addition of PAN provides a homogeneous suspension. The addition of Al{sub 2}O{sub 3} particles causes a slight increase of the triiodide diffusion constants. Furthermore the suggested enhancement of the charge transfer rate shows a dependence on the size of the particles. (author)

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

    Directory of Open Access Journals (Sweden)

    Michał Wlazło

    2013-08-01

    Full Text Available The solubility of β-cyclodextrin (β-CD in ionic liquids (ILs and the activity coefficients at infinite dilution ( 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Ang Teck

    2012-09-01

    Full Text Available Abstract 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.

  11. Anisotropic thermal expansion in a metal-organic framework.

    Science.gov (United States)

    Madsen, Solveig Røgild; Lock, Nina; Overgaard, Jacob; Iversen, Bo Brummerstedt

    2014-06-01

    Ionothermal reaction between Mn(II)(acetate)2·4H2O and 1,3,5-benzenetricarboxylic acid (H3BTC) in either of the two ionic liquids 1-ethyl-3-methylimidazolium bromide (EMIMBr) and 1-ethyl-3-methylimidazolium tosylate (EMIMOTs) resulted in the formation of the new metal-organic framework (MOF) EMIM[Mn(II)BTC] (BTC = 1,3,5-benzenetricarboxylate). The compound crystallizes in the orthorhombic space group Pbca with unit-cell parameters of a = 14.66658 (12), b = 12.39497 (9), c = 16.63509 (14) Å at 100 K. Multi-temperature single-crystal (15-340 K) and powder X-ray diffraction studies (100-400 K) reveal strongly anisotropic thermal expansion properties. The linear thermal expansion coefficients, αL(l), attain maximum values at 400 K along the a- and b-axis, with αL(a) = 115 × 10(-6) K(-1) and αL(b) = 75 × 10(-6) K(-1). At 400 K a negative thermal expansion coefficient of -40 × 10(-6) K(-1) is observed along the c-axis. The thermal expansion is coupled to a continuous deformation of the framework, which causes the structure to expand in two directions. Due to the rigidity of the linker, the expansion in the ab plane causes the network to contract along the c-axis. Hirshfeld surface analysis has been used to describe the interaction between the framework structure and the EMIM cation that resides within the channel. This reveals a number of rather weak interactions and one governing hydrogen-bonding interactions.

  12. Accelerating rate calorimetry studies of the reactions between ionic liquids and charged lithium ion battery electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yadong; Dahn, J.R. [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS (Canada); Zaghib, K.; Guerfi, A. [Institut de Recherche d' Hydro-Quebec, 1800 Lionel-Boulet, Varennes, Que. (Canada); Bazito, Fernanda F.C.; Torresi, Roberto M. [Instituto de Quimica Universidade de Sao Paulo, CP 26077, 05513-970 Sao Paulo (Brazil)

    2007-06-30

    Using accelerating rate calorimetry (ARC), the reactivity between six ionic liquids (with and without added LiPF{sub 6}) and charged electrode materials is compared to the reactivity of standard carbonate-based solvents and electrolytes with the same electrode materials. The charged electrode materials used were Li{sub 1}Si, Li{sub 7}Ti{sub 4}O{sub 12} and Li{sub 0.45}CoO{sub 2}. The experiments showed that not all ionic liquids are safer than conventional electrolytes/solvents. Of the six ionic liquids tested, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMI-FSI) shows the worst safety properties, and is much worse than conventional electrolyte. 1-Ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMI-TFSI) and 1-propyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide (Py13-FSI) show similar reactivity to carbonate-based electrolyte. The three ionic liquids 1-butyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide (BMMI-TFSI), 1-butyl-1-methylpiperidinium bis(trifluoromethanesulfonyl)imide (Pp14-TFSI) and N-trimethyl-N-butylammonium bis(trifluoromethanesulfonyl)imide (TMBA-TFSI) show similar reactivity and are much safer than the conventional carbonate-based electrolyte. A comparison of the reactivity of ionic liquids with common anions and cations shows that ionic liquids with TFSI{sup -} are safer than those with FSI{sup -}, and liquids with EMI{sup +} are worse than those with BMMI{sup +}, Py13{sup +}, Pp14{sup +} and TMBA{sup +}. (author)

  13. Direct electrochemistry and electrocatalysis of hemoglobin in graphene oxide and ionic liquid composite film

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Wei, E-mail: swyy26@hotmail.com [College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China); Gong, Shixing [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Shi, Fan [College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China); Cao, Lili; Ling, Luyang [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Zheng, Weizhe; Wang, Wencheng [College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China)

    2014-07-01

    In this paper a novel sensing platform based on graphene oxide (GO), ionic liquid (IL) 1-ethyl-3-methylimidazolium tetrafluoroborate and Nafion for the immobilization of hemoglobin (Hb) was adopted with a carbon ionic liquid electrode (CILE) as the substrate electrode, which was denoted as Nafion/Hb–GO–IL/CILE. Spectroscopic results suggested that Hb molecules were not denatured in the composite. A pair of well-defined redox peaks appeared on the cyclic voltammogram, which was attributed to the realization of direct electron transfer of Hb on the electrode. Electrochemical behaviors of Hb entrapped in the film were carefully investigated by cyclic voltammetry with the electrochemical parameters calculated. Based on the catalytic ability of the immobilized Hb, Nafion/Hb–GO–IL/CILE exhibited excellent electrocatalytic behavior towards the reduction of different substrates such as trichloroacetic acid in the concentration range from 0.01 to 40.0 mM with the detection limit as 3.12 μM (3σ), H{sub 2}O{sub 2} in the concentration range from 0.08 to 635.0 μM with the detection limit as 0.0137 μM (3σ) and NaNO{sub 2} in the concentration range from 0.5 to 800.0 μM with the detection limit as 0.0104 μM (3σ). So the proposed bioelectrode could be served as a new third-generation electrochemical sensor without mediator. - Highlights: • A graphene oxide, 1-ethyl-3-methylimidazolium tetrafluoroborate and hemoglobin composite were prepared. • Composite modified carbon ionic liquid electrode was fabricated. • Direct electrochemistry of hemoglobin was realized on the modified electrode. • Bioelectrocatalytic reduction of the modified electrode to different substrates was studied.

  14. 瞬间弹射蒸汽爆破增强离子液体对水稻秸秆的预处理效果%Enhanced effects of ionic liquid pretreatment on rice straw by instant catapult steam explosion

    Institute of Scientific and Technical Information of China (English)

    覃锦程; 郝学密; 刘黎阳; 刘晨光; 白凤武

    2015-01-01

    选取具有不同组分分离效果的离子液体 1-乙基-3-甲基咪唑醋酸盐([Emim]Ac)和 1-乙基-3-甲基咪唑氯盐([Emim]Cl),并联用瞬间弹射蒸汽爆破(instant catapult steam explosion, ICSE)对水稻秸秆进行预处理.离子液体导致了组分的重排,使纤维素更多地暴露于物料表面,同时减弱了木质素对纤维素紧密交联的程度.ICSE的使用提升了离子液体的预处理效果,酶解糖收率比单纯使用离子液体升高了14.83%([Emim]Ac)和13.14%([Emim]Cl),其中ICSE联用[Emim]Ac的糖收率最高达97.00%.采用扫描电镜(SEM)和热重分析仪(TGA)进行物料结构分析,证实了ICSE联用离子液体有助于破坏物料的致密结构,增加无定形区,从而提高酶解糖收率.%In this study, two kinds of ionic liquid, including 1-ethyl-3-methylimidazolium acetate and 1-ethyl-3-methylimidazolium chloride were used to pretreat rice straw with instant catapult steam explosion (ICSE). The rearrangement of components were caused by ionic liquid pretreatment, which made more cellulose exposed at the surface of rice straw and weakened the cross-link between lignin and cellulose. Through enzymatic hydrolysis analysis, ICSE enhanced the effects of ionic liquid pretreatment by improving the sugar yield. Compared with the sugar yield as using ionic liquid alone, the sugar yield as combination of ICSE and ionic liquid increased by 14.83% ([Emim]Ac) and 13.14% ([Emim]Cl). The highest value reached 97.00% under the pretreatment by ICSE combine with [Emim]Ac. The structural changes were also analyzed by scanning electron microscope (SEM) and thermo gravimetric analysis (TGA). The pretreated materials became more porous with larger amorphous region, and consequently the sugar yield raised.

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

    Directory of Open Access Journals (Sweden)

    Karatzos Sergios

    2012-08-01

    Full Text Available Abstract 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

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

    Science.gov (United States)

    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

  17. Experimental investigations of an ionic-liquid-based, magnesium ion conducting, polymer gel electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, G.P.; Hashmi, S.A. [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

    2009-02-15

    Studies on a novel magnesium ion conducting gel polymer electrolyte based on a room temperature ionic liquid (RTIL) is reported. It comprises a Mg-salt, Mg(CF{sub 3}SO{sub 3}){sub 2} [or magnesium triflate, Mg(Tf){sub 2}] solution in an ionic liquid, 1-ethyl-3-methylimidazolium trifluoro-methanesulfonate (EMITf), immobilized with poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP), which is a freestanding, semitransparent and flexible film with excellent mechanical strength. Physical and electrochemical analyses demonstrate promising characteristics of these films, suitable as electrolytes in rechargeable magnesium batteries. The material offers a maximum electrical conductivity of {proportional_to}4.8 x 10{sup -3} S cm{sup -1} at room temperature (20 C) with excellent thermal and electrochemical stabilities. Possible conformational changes in the polymer host PVdF-HFP due to ionic liquid solution entrapment and ion-polymer interaction are investigated by Fourier transform infra-red (FTIR), X-ray diffraction (XRD) and scanning electron microscopic (SEM) methods. The Mg{sup 2+} ion transport in the gel film is confirmed from cyclic voltammetry, impedance and transport number measurements. The Mg{sup 2+} ion transport number (t{sub +}) is {proportional_to}0.26, which indicates a substantial contribution of triflate anion transport along with ionic conduction due to the component ions of the ionic liquid. (author)

  18. Experimental investigations of an ionic-liquid-based, magnesium ion conducting, polymer gel electrolyte

    Science.gov (United States)

    Pandey, G. P.; Hashmi, S. A.

    Studies on a novel magnesium ion conducting gel polymer electrolyte based on a room temperature ionic liquid (RTIL) is reported. It comprises a Mg-salt, Mg(CF 3SO 3) 2 [or magnesium triflate, Mg(Tf) 2] solution in an ionic liquid, 1-ethyl-3-methylimidazolium trifluoro-methanesulfonate (EMITf), immobilized with poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP), which is a freestanding, semitransparent and flexible film with excellent mechanical strength. Physical and electrochemical analyses demonstrate promising characteristics of these films, suitable as electrolytes in rechargeable magnesium batteries. The material offers a maximum electrical conductivity of ∼4.8 × 10 -3 S cm -1 at room temperature (20 °C) with excellent thermal and electrochemical stabilities. Possible conformational changes in the polymer host PVdF-HFP due to ionic liquid solution entrapment and ion-polymer interaction are investigated by Fourier transform infra-red (FTIR), X-ray diffraction (XRD) and scanning electron microscopic (SEM) methods. The Mg 2+ ion transport in the gel film is confirmed from cyclic voltammetry, impedance and transport number measurements. The Mg 2+ ion transport number (t +) is ∼0.26, which indicates a substantial contribution of triflate anion transport along with ionic conduction due to the component ions of the ionic liquid.

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

    Directory of Open Access Journals (Sweden)

    Isao Shimoyama

    2013-03-01

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

  20. Ratiometric optical temperature sensor using two fluorescent dyes dissolved in an ionic liquid encapsulated by Parylene film.

    Science.gov (United States)

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

    2013-03-27

    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.

  1. Sensors for Highly Toxic Gases: Methylamine and Hydrogen Chloride Detection at Low Concentrations in an Ionic Liquid on Pt Screen Printed Electrodes

    Science.gov (United States)

    Murugappan, Krishnan; Silvester, Debbie S.

    2015-01-01

    Commercially available Pt screen printed electrodes (SPEs) have been employed as possible electrode materials for methylamine (MA) and hydrogen chloride (HCl) gas detection. The room temperature ionic liquid (RTIL) 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][NTf2]) was used as a solvent and the electrochemical behaviour of both gases was first examined using cyclic voltammetry. The reaction mechanism appears to be the same on Pt SPEs as on Pt microelectrodes. Furthermore, the analytical utility was studied to understand the behaviour of these highly toxic gases at low concentrations on SPEs, with calibration graphs obtained from 10 to 80 ppm. Three different electrochemical techniques were employed: linear sweep voltammetry (LSV), differential pulse voltammetry (DPV) and square wave voltammetry (SWV), with no significant differences in the limits of detection (LODs) between the techniques (LODs were between 1.4 to 3.6 ppm for all three techniques for both gases). The LODs achieved on Pt SPEs were lower than the current Occupational Safety and Health Administration Permissible Exposure Limit (OSHA PEL) limits of the two gases (5 ppm for HCl and 10 ppm for MA), suggesting that Pt SPEs can successfully be combined with RTILs to be used as cheap alternatives for amperometric gas sensing in applications where these toxic gases may be released. PMID:26506358

  2. Sensors for Highly Toxic Gases: Methylamine and Hydrogen Chloride Detection at Low Concentrations in an Ionic Liquid on Pt Screen Printed Electrodes

    Directory of Open Access Journals (Sweden)

    Krishnan Murugappan

    2015-10-01

    Full Text Available Commercially available Pt screen printed electrodes (SPEs have been employed as possible electrode materials for methylamine (MA and hydrogen chloride (HCl gas detection. The room temperature ionic liquid (RTIL 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonylimide ([C2mim][NTf2] was used as a solvent and the electrochemical behaviour of both gases was first examined using cyclic voltammetry. The reaction mechanism appears to be the same on Pt SPEs as on Pt microelectrodes. Furthermore, the analytical utility was studied to understand the behaviour of these highly toxic gases at low concentrations on SPEs, with calibration graphs obtained from 10 to 80 ppm. Three different electrochemical techniques were employed: linear sweep voltammetry (LSV, differential pulse voltammetry (DPV and square wave voltammetry (SWV, with no significant differences in the limits of detection (LODs between the techniques (LODs were between 1.4 to 3.6 ppm for all three techniques for both gases. The LODs achieved on Pt SPEs were lower than the current Occupational Safety and Health Administration Permissible Exposure Limit (OSHA PEL limits of the two gases (5 ppm for HCl and 10 ppm for MA, suggesting that Pt SPEs can successfully be combined with RTILs to be used as cheap alternatives for amperometric gas sensing in applications where these toxic gases may be released.

  3. Measurement of thermal conductivity, viscosity and density of ionic liquid [EMIM][DEP]-based nanofluids☆

    Institute of Scientific and Technical Information of China (English)

    Hua Xie; Zongchang Zhao; Jianhua Zhao; Hongtao Gao

    2016-01-01

    This article studied experimental y the effect of multi-wall carbon nanotubes (MWCNTs) on the thermo physical properties of ionic liquid-based nanofluids. The nanofluids were composed of ionic liquid, 1-ethyl-3-methylimidazolium diethylphosphate [EMIM][DEP], or its aqueous solution[EMIM][DEP](1)+H2O(2) and MWCNTs without any surfactants. The thermal conductivity, viscosity and density of the nanofluids were mea-sured experimental y. The effects of the mass fraction of MWCNTs, temperature and the mole fraction of water on the thermo physical properties of nanofluids were studied. Results show that the thermal conductivity of nanofluids increases within the range of 1.3%–9.7%compared to their base liquids, and have a well linear depen-dence on temperature. The viscosity and density of the nanofluids exhibit a remarkable increase compared with those of the base liquids. Finally, the correlation of the effective thermal conductivity and viscosity of the nanofluids was made using the models in the literatures.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-08-15

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

  5. Bilayer membrane permeability of ionic liquid-filled block copolymer vesicles in aqueous solution.

    Science.gov (United States)

    Bai, Zhifeng; Zhao, Bin; Lodge, Timothy P

    2012-07-19

    The bilayer membrane permeability of block copolymer vesicles ("polymersomes") with ionic liquid interiors dispersed in water is quantified using fluorescence quenching. Poly((1,2-butadiene)-b-ethylene oxide) (PB-PEO) block copolymer vesicles in water with their interiors filled with a common hydrophobic ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, were prepared containing a hydrophobic dye, Nile Red, by intact migration of dye-encapsulated vesicles from the ionic liquid to water at room temperature. A small quencher molecule, dichloroacetamide, was added to the aqueous solution of the dye-loaded vesicles, and the permeation of the quencher passing through the membrane into the interior was determined from the fluorescence quenching kinetics. Rapid permeation of the quencher across the nanoscale membrane was observed, consistent with the high fluidity of the liquid polybutadiene membrane. Two different PB-PEO copolymers were employed, in order to vary the thickness of the solvophobic membrane. A significant increase in membrane permeability was also observed with decreasing membrane thickness, which is tentatively attributable to differences in quencher solubility in the membranes. Quantitative migration of the vesicles from the aqueous phase back to an ionic liquid phase was achieved upon heating. These microscopically heterogeneous and thermoresponsive vesicles with permeable and robust membranes have potential as recyclable nanoreactors, in which the high viscosity and capital expense of an ionic liquid reaction medium can be mitigated, while retaining the desirable features of ionic liquids as reaction media, and facile catalyst recovery.

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

    Directory of Open Access Journals (Sweden)

    Clara Casado-Coterillo

    2014-06-01

    Full Text Available 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.

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

    Science.gov (United States)

    Casado-Coterillo, Clara; Del Mar López-Guerrero, María; Irabien, Angel

    2014-06-19

    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.

  8. Soft shape-adaptive gripping device made from artificial muscle

    Science.gov (United States)

    Hamburg, E.; Vunder, V.; Johanson, U.; Kaasik, F.; Aabloo, A.

    2016-04-01

    We report on a multifunctional four-finger gripper for soft robotics, suitable for performing delicate manipulation tasks. The gripping device is comprised of separately driven gripping and lifting mechanisms, both made from a separate single piece of smart material - ionic capacitive laminate (ICL) also known as artificial muscle. Compared to other similar devices the relatively high force output of the ICL material allows one to construct a device able to grab and lift objects exceeding multiple times its own weight. Due to flexible design of ICL grips, the device is able to adapt the complex shapes of different objects and allows grasping single or multiple objects simultaneously without damage. The performance of the gripper is evaluated in two different configurations: a) the ultimate grasping strength of the gripping hand; and b) the maximum lifting force of the lifting actuator. The ICL is composed of three main layers: a porous membrane consisting of non-ionic polymer poly(vinylidene fluoride-co-hexafluoropropene) (PVdF-HFP), ionic liquid 1-ethyl-3-methylimidazolium trifluoromethane-sulfonate (EMITFS), and a reinforcing layer of woven fiberglass cloth. Both sides of the membrane are coated with a carbonaceous electrode. The electrodes are additionally covered with thin gold layers, serving as current collectors. Device made of this material operates silently, requires low driving voltage (<3 V), and is suitable for performing tasks in open air environment.

  9. Development of Formaldehyde Biosensor for Determination of Formalin in Fish Samples; Malabar Red Snapper (Lutjanus malabaricus) and Longtail Tuna (Thunnus tonggol).

    Science.gov (United States)

    Noor Aini, Bohari; Siddiquee, Shafiquzzaman; Ampon, Kamaruzaman

    2016-06-30

    Electrochemical biosensors are widely recognized in biosensing devices due to the fact that gives a direct, reliable, and reproducible measurement within a short period. During bio-interaction process and the generation of electrons, it produces electrochemical signals which can be measured using an electrochemical detector. A formaldehyde biosensor was successfully developed by depositing an ionic liquid (IL) (e.g., 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM][Otf])), gold nanoparticles (AuNPs), and chitosan (CHIT), onto a glassy carbon electrode (GCE). The developed formaldehyde biosensor was analyzed for sensitivity, reproducibility, storage stability, and detection limits. Methylene blue was used as a redox indicator for increasing the electron transfer in the electrochemical cell. The developed biosensor measured the NADH electron from the NAD⁺ reduction at a potential of 0.4 V. Under optimal conditions, the differential pulse voltammetry (DPV) method detected a wider linear range of formaldehyde concentrations from 0.01 to 10 ppm within 5 s, with a detection limit of 0.1 ppm. The proposed method was successfully detected with the presence of formalin in fish samples, Lutjanus malabaricus and Thunnus Tonggol. The proposed method is a simple, rapid, and highly accurate, compared to the existing technique.

  10. Development of Formaldehyde Biosensor for Determination of Formalin in Fish Samples; Malabar Red Snapper (Lutjanus malabaricus and Longtail Tuna (Thunnus tonggol

    Directory of Open Access Journals (Sweden)

    Bohari Noor Aini

    2016-06-01

    Full Text Available Electrochemical biosensors are widely recognized in biosensing devices due to the fact that gives a direct, reliable, and reproducible measurement within a short period. During bio-interaction process and the generation of electrons, it produces electrochemical signals which can be measured using an electrochemical detector. A formaldehyde biosensor was successfully developed by depositing an ionic liquid (IL (e.g., 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM][Otf], gold nanoparticles (AuNPs, and chitosan (CHIT, onto a glassy carbon electrode (GCE. The developed formaldehyde biosensor was analyzed for sensitivity, reproducibility, storage stability, and detection limits. Methylene blue was used as a redox indicator for increasing the electron transfer in the electrochemical cell. The developed biosensor measured the NADH electron from the NAD+ reduction at a potential of 0.4 V. Under optimal conditions, the differential pulse voltammetry (DPV method detected a wider linear range of formaldehyde concentrations from 0.01 to 10 ppm within 5 s, with a detection limit of 0.1 ppm. The proposed method was successfully detected with the presence of formalin in fish samples, Lutjanus malabaricus and Thunnus Tonggol. The proposed method is a simple, rapid, and highly accurate, compared to the existing technique.

  11. Combined effects of raw materials and solvent systems on the preparation and properties of regenerated cellulose fibers.

    Science.gov (United States)

    Chen, Jinghuan; Guan, Ying; Wang, Kun; Zhang, Xueming; Xu, Feng; Sun, Runcang

    2015-09-05

    To investigate the combined effects of materials and solvents on the preparation, structural and mechanical properties of regenerated cellulose fibers, four cellulosic materials (microcrystalline cellulose, cotton linter pulp, bamboo pulp and bleached softwood sulfite dissolving pulp) and six non-derivative solvents (NaOH/urea aqueous solution, N,N-dimethylacetamide/lithium chloride, N-methyl-morpholine-N-oxide, 1-butyl-3-methylimidazolium chloride, 1-allyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazolium acetate) were used to prepare fibers with wet spinning method. The results showed that the dissolvability of solvent was the determining factor in cellulose dissolution, and the dissolving time was influenced by the raw materials' properties, such as molecular weight, exposed area and hemicellulose content. The crystallinity and elongation at break of the fibers were almost fixed and not affected by the materials and solvents. However, the tensile strength of the fibers was directly proportional to the molecular weight of the raw materials, and varied with the type of solvents through cellulose degradation.

  12. Polymer Sensitized Quasi Solid-State Photovoltaic Cells Using Derivatives of Polythiophene

    Institute of Scientific and Technical Information of China (English)

    G.K.R.Senadeera; J.M.R.C. Fernando

    2006-01-01

    Substituted thiophene sensitized, nanocrystalline TiO2-based quasi solid-state solar cells were fabricated by using either poly (3-thiophene acetic acid) (P3TAA) or a copolymer with poly (3-thiophene acetic acid)-poly (hexyl thiophene) (P3TAA-PHT) polymers and copper iodide (Cul) as a hole conducting material together with an ionic liquid 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) amide and lithium bis (trifluoromethanesulfone) imide as additives for charge transport promotion. Dramatic enhancements in the cell performances were observed with the additives in Cul. While the cell sensitized with P3TAA generated a conversion efficiency of ~0.3% under simulated full sunlight of 100 mW.cm-2 (air mass: 1.5), the cell sensitized with copolymer P3TAA-PHT delivered ~0.25% efficiency under the same conditions with ~1.23 mA.cm-2 as photocurrent and ~371 mV as photovoltage.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  15. Coulometric differential FFT admittance voltammetry determination of Amlodipine in pharmaceutical formulation by nano-composite electrode.

    Science.gov (United States)

    Norouzi, Parviz; Gupta, Vinod Kumar; Larijani, Bagher; Rasoolipour, Solmaz; Faridbod, Farnoush; Ganjali, Mohammad R

    2015-01-01

    An electrochemical detection technique based on combination of was coulometric differential fast Fourier transformation admittance voltammetry (CDFFTAV) and nano-composite film modified glassy carbon electrode was successfully applied for sensitive determination of Amlodipine. The nano-composite film was made by a mixture of ionic liquid, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4), multiwall carbon nanotube and Au nanoparticles as electrochemical mediators. Studies reveal that the irreversible oxidation of Amlodipine was highly facile on the electrode surface. The electrochemical response was established on calculation of the charge under the admittance peak, which was obtained by discrete integration of the admittance response in a selected potential range, obtained in a flow injection analysis. Once established the best operative optimum conditions, the resulting nano-composite film electrode showed a catalytic effect on the oxidation of the analyte. The response is linear in the Amlodipine concentration range of 1.0 × 10(-9) to 2.0 × 10(-7)M with a detection limit of 1.25 × 10(-10)M. Moreover, the proposed technique exhibited high sensitivity, fast response time (less than 6s) and long-term stability and reproducibility around 96%, and it was successfully used to the determination of Amlodipine content in the pharmaceutical formulation.

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

    Science.gov (United States)

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

    2016-07-14

    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.

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

    Science.gov (United States)

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

    2014-06-15

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

  18. Capacitance of Ti3C2Tx MXene in ionic liquid electrolyte

    Science.gov (United States)

    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.

  19. Influence of the molecular-oriented structure of ionic liquids on the crystallinity of aluminum hydroxide prepared by a sol-gel process in ionic liquids.

    Science.gov (United States)

    Kinoshita, K; Yanagimoto, H; Suzuki, T; Minami, H

    2015-07-28

    The influence of the structure of ionic liquids on the crystallinity of aluminum hydroxide (Al(OH)3) prepared by a sol-gel process with aluminum isopropoxide (Al(OPr(i))3) in imidazolium-based ionic liquids was investigated. When Al(OH)3 was prepared in ionic liquids having long alkyl chains, such as 1-butyl-3-methylimidazolium salts and 1-methyl-3-octylimidazolium salts, highly crystalline products were obtained. In contrast, Al(OH)3 obtained using the 1-ethyl-3-methylimidazolium salt was an amorphous material, indicating that hydrophobic interaction of the alkyl tail of the imidazolium cation of the ionic liquid strongly affects the crystallinity of sol-gel products and the local structure of the ionic liquid. Moreover, the crystallinity of Al(OH)3 prepared in ionic liquids increased relative to the amount of additional water (ionic liquid/water = 1.28/2.0-3.5/0.2, w/w). In the case of addition of a small amount of water (ionic liquid/water = 3.5/0.2, w/w), the product was amorphous. These results implied that the presence of an ionic liquid and a sufficient amount of water was crucial for the successful synthesis of sol-gel products with high crystallinity. (1)H NMR analyses revealed a shift of the peak associated with the imidazolium cation upon addition of water, which suggested that the molecular orientation of the ionic liquid was similar to that of a micelle.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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).

  2. 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.

    Science.gov (United States)

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

    2013-12-04

    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.

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

    Science.gov (United States)

    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.

  4. Analysis of SEI formed with cyano-containing imidazolium-based ionic liquid electrolyte in lithium secondary batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Liwei; Yamaki, Jun-ichi [Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasuga-Koen, Kasuga, Fukuoka 816-8580 (Japan); Egashira, Minato [Department of Applied Chemistry and Chemical Engineering, Faculty of Engineering, Yamaguchi University, 2-16-1, Yamaguchi 755-8611 (Japan)

    2007-12-06

    Two kinds of cyano-containing imidazolium-based ionic liquid, 1-cyanopropyl-3-methylimidazolium-bis(trifluoromethanesulfonyl)imide (CpMI-TFSI) and 1-cyanomethyl-3-methylimidazolium-bis(trifluoromethanesulfonyl)imide (CmMI-TFSI), each of which contained 20 wt% dissolved LiTFSI, were used as electrolytes for lithium secondary batteries. Compared with 1-ethyl-3-methylimidazolium-bis(trifluoromethane-sulfonyl)imide (EMI-TFSI) electrolyte, a reversible lithium deposition/dissolution on a stainless-steel working electrode was observed during CV measurements in these cyano-containing electrolytes, which indicated that a passivation layer (solid electrolyte interphase, SEI) was formed during potential scanning. The morphology of the working electrode with each electrolyte system was studied by SEM. Different dentrite forms were found on the electrodes with each electrolyte. The SEI that formed in CpMI-TFSI electrolyte showed the best passivating effect, while the deposited film formed in EMI-TFSI electrolyte showed no passivating effect. The chemical characteristics of the deposited films on the working electrodes were compared by XPS measurements. A component with a cyano group was found in SEIs in CpMI-TFSI and CmMI-TFSI electrolytes. The introduction of a cyano functional group suppressed the decomposition of electrolyte and improved the cathodic stability of the imidazolium-based ionic liquid. The reduction reaction route of imidazolium-based ionic liquid was considered to be different depending on whether or not the molecular structure contained a cyano functional group. (author)

  5. Pressure effects on Emim[FeCl4], a magnetic ionic liquid with three-dimensional magnetic ordering.

    Science.gov (United States)

    García-Saiz, Abel; de Pedro, Imanol; Blanco, Jesús A; González, Jesús; Rodríguez Fernández, Jesús

    2013-03-21

    We report a combined study using magnetization and Raman spectroscopy on the magnetic ionic liquid 1-ethyl-3-methylimidazolium tetrachloroferrate, Emim[FeCl4]. This material shows a long-range antiferromagnetic ordering below the Néel temperature T(N) ≈ 3.8 K. The effects of pressure on the magnetic properties have been studied using a miniature piston-cylinder CuBe pressure cell. This three-dimensional ordering is strongly influenced when hydrostatic pressure is applied. It is observed that low applied pressure is enough to modify the magnetic interactions, inducing a transition from antiferromagnetic to ferrimagnetic ordering. Raman spectroscopy measurements reveal important information about the existence of isolated [FeCl4](-) anions and the absence of dimeric [Fe2Cl7](-) units in the liquid and solid states. These features seem to suggest that the superexchange pathways responsible for the appearance of magnetic ordering are mediated through Fe-Cl-Cl-Fe. Furthermore, the liquid-solid phase transition exhibits a magnetic hysteresis near room temperature, which can be tuned by weak pressures.

  6. An Approach to Solid-State Electrical Double Layer Capacitors Fabricated with Graphene Oxide-Doped, Ionic Liquid-Based Solid Copolymer Electrolytes

    Directory of Open Access Journals (Sweden)

    N. F. A. Fattah

    2016-06-01

    Full Text Available Solid polymer electrolyte (SPE composed of semi-crystalline poly (vinylidene fluoride-hexafluoropropylene [P(VdF-HFP] copolymer, 1-ethyl-3-methylimidazolium bis (trifluoromethyl sulphonyl imide [EMI-BTI] and graphene oxide (GO was prepared and its performance evaluated. The effects of GO nano-filler were investigated in terms of enhancement in ionic conductivity along with the electrochemical properties of its electrical double layer capacitors (EDLC. The GO-doped SPE shows improvement in ionic conductivity compared to the P(VdF-HFP-[EMI-BTI] SPE system due to the existence of the abundant oxygen-containing functional group in GO that assists in the improvement of the ion mobility in the polymer matrix. The complexation of the materials in the SPE is confirmed in X-ray diffraction (XRD and thermogravimetric analysis (TGA studies. The electrochemical performance of EDLC fabricated with GO-doped SPE is examined using cyclic voltammetry and charge–discharge techniques. The maximum specific capacitance obtained is 29.6 F∙g−1, which is observed at a scan rate of 3 mV/s in 6 wt % GO-doped, SPE-based EDLC. It also has excellent cyclic retention as it is able keep the performance of the EDLC at 94% even after 3000 cycles. These results suggest GO doped SPE plays a significant role in energy storage application.

  7. Spectral insights into gelation microdynamics of PNIPAM in an ionic liquid.

    Science.gov (United States)

    Wang, Zhangwei; Wu, Peiyi

    2011-09-15

    The gelation microdynamic mechanism of PNIPAM in a ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C(2)mim][NTf(2)]), is investigated by FTIR spectroscopy in combination with two-dimensional correlation spectroscopy (2Dcos) and perturbation correlation moving window (PCMW) technique for the first time. Appreciable changes in band frequencies and shapes are observed in the ν(N-H) and ν(C═O) regions, indicating the formation of new interactions between the ionic liquid and PNIPAM and the transformation of interior interaction between polymer chains during gelation. In particular, the variation of the ion environment with the relative change of the isolated and associated components of [C(2)mim][NTf(2)] on the sol-to-gel transition of PNIPAM is revealed by 2DIR analysis to the ν(C-H) region of imidazole ring. Upon cooling, the side chains of PNIPAM experience a changing process from dissociation of the interaction with ionic liquid to formation of N-H···O═C hydrogen bonding, then polymer shrinks from the side chains to backbone, followed by the final immobilization of the associated species in polymer network. Meanwhile, the gelation is actually a desolvation process upon the variation of ion environment.

  8. An ionic liquid supported CeO2 nanoparticles-carbon nanotubes composite-enhanced electrochemical DNA-based sensor for the detection of Pb2+

    Institute of Scientific and Technical Information of China (English)

    Yan Lia; Xiao-Rong Liut; Xiao-Hui Ning; Can-Can Hnang; Jian-Bin Zheng; Jun-cai Zhang

    2011-01-01

    An electrochemical sensor incorporating a signal enhancement for the determination of lead (II) ions (Pb2+) was designed on the basis of the thrombin-binding aptamer (TBA) as a molecular recog- nition element and ionic liquid supported cerium oxide (CeO2) nanoparticles-carbon nanotubes compo- site modification. The composite comprises nanoparticles CeO2, multi-waU carbon nanotubes (MWNTs) and hydrophobic room temperature ionic liquid (RTIL) 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4). The electrochemical sensors were fabricated by immersing the CeOa-MWNTs-EMIMBF4 modified glassy carbon electrode (GCE) into the solution of TBA probe. In the presence of Pb2+, the TBA probe could form stable G-quartet structure by the specific binding interactions between Pb2+ and TBA. The TBA-bound Pb2+ can be electrochemically reduced, which provides a readout signal for quantitative detection of Pb2+. The reduction peak current is linearly related to the concentration of Pb2+ from 1.0 * 10-8 M to 1.0 * 105 M with a detection limit of 5 * 109 M. This work demonstrates that the CeOz-MWNTs-EMIMBF4 nanocomposite modified GCE provides a promising platform for immobi- lizing the TBA probe and enhancing the sensitivity of the DNA-based sensors.

  9. Energy properties of an EMI-Im ionic liquid ion source

    Science.gov (United States)

    Lozano, Paulo C.

    2006-01-01

    The identity and the energy distributions of positive and negative ions electrostatically extracted from the liquid phase in an ionic liquid ion source (ILIS) are analysed with a time-of-flight mass spectrometer and a multi-grid retarding potential analyzer. Accurate energy measurements using ionic liquids in an externally wetted configuration are reported for the first time. Droplet-free beams are produced using the ionic liquid 1-ethyl-3-methylimidazolium bis(triflouromethylsulfonyl)amide (EMI-Im) in which the solvated ions (EMI-Im)nEMI+ and (EMI-Im)nIm- with n = 0,1,2 are observed. The small ion source size and the energy distribution widths and deficits of a few electronvolts are quite similar to those of liquid metal ion sources, confirming that ILIS can be used in applications requiring highly focusable beams, e.g. sub-micron ion lithography. Measurements also suggest that solvated ions with n >= 1 exhibit post-extraction fragmentation into lighter species at a rate increasing with their original degree of solvation. About 10% of the total beam current is carried away by metastable species that break up almost immediately after extraction while inside the emitter accelerating region.

  10. Energy properties of an EMI-Im ionic liquid ion source

    Energy Technology Data Exchange (ETDEWEB)

    Lozano, Paulo C [Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room 37-438, Cambridge, MA 02139 (United States)

    2006-01-07

    The identity and the energy distributions of positive and negative ions electrostatically extracted from the liquid phase in an ionic liquid ion source (ILIS) are analysed with a time-of-flight mass spectrometer and a multi-grid retarding potential analyzer. Accurate energy measurements using ionic liquids in an externally wetted configuration are reported for the first time. Droplet-free beams are produced using the ionic liquid 1-ethyl-3-methylimidazolium bis(triflouromethylsulfonyl)amide (EMI-Im) in which the solvated ions (EMI-Im){sub n}EMI{sup +} and (EMI-Im){sub n}Im{sup -} with n = 0,1,2 are observed. The small ion source size and the energy distribution widths and deficits of a few electronvolts are quite similar to those of liquid metal ion sources, confirming that ILIS can be used in applications requiring highly focusable beams, e.g. sub-micron ion lithography. Measurements also suggest that solvated ions with n {>=} 1 exhibit post-extraction fragmentation into lighter species at a rate increasing with their original degree of solvation. About 10% of the total beam current is carried away by metastable species that break up almost immediately after extraction while inside the emitter accelerating region.

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

    Science.gov (United States)

    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.

  12. 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.

    Science.gov (United States)

    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.

  13. Isolation and characterisation of 1-alkyl-3-methylimidazolium chloride ionic liquid-tolerant and biodegrading marine bacteria.

    Directory of Open Access Journals (Sweden)

    Julianne Megaw

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  15. Characterization of the Micromorphology and Topochemistry of Poplar Wood during Mild Ionic Liquid Pretreatment for Improving Enzymatic Saccharification

    Directory of Open Access Journals (Sweden)

    Sheng Chen

    2017-01-01

    Full Text Available Ionic liquids (ILs as designer solvents have been applied in biomass pretreatment to increase cellulose accessibility and therefore improve the enzymatic hydrolysis. We investigated the characterization of the micromorphology and the topochemistry of poplar wood during 1-ethyl-3-methylimidazolium acetate pretreatment with mild conditions (90 °C for 20 and 40 min by multiple microscopic techniques (FE-SEM, CLSM, and CRM. Chemical composition analysis, XRD, cellulase adsorption isotherm, and enzymatic hydrolysis were also performed to monitor the variation of substrate properties. Our results indicated that the biomass conversion was greatly enhanced (from 20.57% to 73.64% due to the cell wall deconstruction and lignin dissolution (29.83% lignin was removed after incubation for 40 min, rather than the decrystallization or crystallinity transformation of substrates. The mild ILs pretreatment, with less energy input, can not only enhance enzymatic hydrolysis, but also provide a potential approach as the first step in improving the sequential pretreatment effectiveness in integrated methods. This study provides new insights on understanding the ILs pretreatment with low temperature and short duration, which is critical for developing individual and/or combined pretreatment technologies with reduced energy consumption.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kelicarslan, A.; Saridede, M. N.

    2016-05-01

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

  17. Effect of ionic liquid pretreatment on the chemical composition, structure and enzymatic hydrolysis of energy cane bagasse.

    Science.gov (United States)

    Qiu, Zenghui; Aita, Giovanna M; Walker, Michelle S

    2012-08-01

    Ionic liquids (ILs) are promising solvents for the pretreatment of lignocellulose as they are thermally stable, environmentally friendly, recyclable, and have low volatility. This study evaluated the effect of 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]) for the pretreatment of energy cane bagasse in terms of biomass composition, structural changes and enzymatic digestibility. Energy cane bagasse was pretreated with [EMIM][OAc] (5% (w/w)) at 120 °C for 30 min followed by hydrolysis with commercially available enzymes, Spezyme CP and Novozyme 188. IL-treated energy cane bagasse resulted in significant lignin removal (32.0%) with slight glucan and xylan losses (8.8% and 14.0%, respectively), and exhibited a much higher enzymatic digestibility (87.0% and 64.3%) than untreated (5.5% and 2.8%) or water-treated (4.0% and 2.1%) energy cane bagasse in terms of both cellulose and hemicellulose digestibilities, respectively. The enhanced digestibilities of IL-treated biomass can be attributed to delignification and reduction of cellulose crystallinity as confirmed by FTIR and XRD analyses.

  18. Determination of phase transition points of ionic liquids by combination of thermal analysis and conductivity measurements at very low heating and cooling rates

    Energy Technology Data Exchange (ETDEWEB)

    Wachter, Philipp; Schreiner, Christian; Schweiger, Hans-Georg [Workgroup Electrochemistry and Electrolytes, Institute of Physical and Theoretical Chemistry, University of Regensburg, Universitaetsstr. 31, D-93040 Regensburg (Germany); Gores, Heiner Jakob, E-mail: Heiner.Gores@Chemie.Uni-Regensburg.d [Workgroup Electrochemistry and Electrolytes, Institute of Physical and Theoretical Chemistry, University of Regensburg, Universitaetsstr. 31, D-93040 Regensburg (Germany)

    2010-07-15

    The determination of phase transition points of nine different ionic liquids (ILs) was performed by thermal analysis with simultaneous recording of conductivity. Conductivity of electrolyte solutions and ILs drastically changes during phase transitions and thus is an additional and very sensitive indicator for measuring phase transition points. Evaluation of temperature-time functions and conductivity-time functions with our computer-coupled automated equipment enabled the determination of melting temperatures with high accuracy and reliability. This claim is based on large samples, low temperature change rates and by regularly repeated measurements, i.e. at least seven measurements per IL. The melting temperatures of 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate, 1-butyl-1-methylpyrrolidinium tris(penta-fluoroethyl)trifluorophosphate, and 1-methyl-3-propylimidazolium iodide were, to our knowledge, determined for the first time. The melting temperatures of the other 1-butyl-1-methylpyrrolidinium-, 1-ethyl-3-methylimidazolium-, 1-hexyl-3-methylimidazolium-, and trimethylsulfonium-based ILs showed either a very good accordance with values published in literature or were distinctly higher.

  19. Polymer-ionic liquid ternary systems for Li-battery electrolytes: Molecular dynamics studies of LiTFSI in a EMIm-TFSI and PEO blend

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Luciano T., E-mail: ltcosta@id.uff.br [Instituto de Química-Departamento de Físico-Química, Universidade Federal Fluminense, Outeiro de São João Batista s/n CEP, 24020-150 Niterói, Rio de Janeiro (Brazil); Sun, Bing; Jeschull, Fabian; Brandell, Daniel [Department of Chemistry—Ångström Laboratory, Uppsala University, P.O. Box 538, SE-751 21 Uppsala (Sweden)

    2015-07-14

    This paper presents atomistic molecular dynamics simulation studies of lithium bis(trifluoromethane)sulfonylimide (LiTFSI) in a blend of 1-ethyl-3-methylimidazolium (EMIm)-TFSI and poly(ethylene oxide) (PEO), which is a promising electrolyte material for Li- and Li-ion batteries. Simulations of 100 ns were performed for temperatures between 303 K and 423 K, for a Li:ether oxygen ratio of 1:16, and for PEO chains with 26 EO repeating units. Li{sup +} coordination and transportation were studied in the ternary electrolyte system, i.e., PEO{sub 16}LiTFSI⋅1.0 EMImTFSI, by applying three different force field models and are here compared to relevant simulation and experimental data. The force fields generated significantly different results, where a scaled charge model displayed the most reasonable comparisons with previous work and overall consistency. It is generally seen that the Li cations are primarily coordinated to polymer chains and less coupled to TFSI anion. The addition of EMImTFSI in the electrolyte system enhances Li diffusion, associated to the enhanced TFSI dynamics observed when increasing the overall TFSI anion concentration in the polymer matrix.

  20. Variation of Particle Size and Pretreatment Temperature to the Crystallinity of Leucaena Leucocephala

    Directory of Open Access Journals (Sweden)

    Mohd Safaai Nor Sharliza

    2016-01-01

    Full Text Available This study was conducted in order to determine the effect of different particle size and pretreatment temperature to the crystallinity of leucaena leucocephala. The leucaena was pretreated by ionic liquid [1-ethyl-3 methylimidazolium acetate [Emim]Ac. There were three different particle sizes that have been tested in this experiment; less than 0.3 mm, 0.5 mm and 0.7 mm. In the other hand, the pretreatment temperature tested were 30°C, 60°C and 90°C. The effect of particle size and pretreatment temperature to the crystallinity of leucaena was investigated by using X-Ray Diffraction (XRD and Scanning Electron Microscopy (SEM. The crystallinity index of the sample represents the percentage of crystalline materials. A lower in the cristallinity index indicated that the material has lower crystillinity, hence give more benefit to the cellulose hydrolysis. From XRD analysis, it shows that the cristallinity index of leucaena decreased with decreasing particle size and increasing pretreatment temperature. SEM analysis also shows that the structure of leucaena has more irregular, porous and destroyed structure with decreasing particle size and increasing pretreatment temperature. Thus, the result from this experiment shows that the smaller particle size and higher pretreatment temperature would provide a more accessible surface area to enhance the cellulose hydrolysis.

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

    Science.gov (United States)

    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.

  2. Heat capacities and glass transitions of ion gels.

    Science.gov (United States)

    Yamamuro, Osamu; Someya, Takenori; Kofu, Maiko; Ueki, Takeshi; Ueno, Kazuhide; Watanabe, Masayoshi

    2012-09-06

    We have investigated thermodynamic properties of ion gels consisting of a PMMA [poly(methyl methacrylate)] network and EMITFSI [1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide] ionic liquid by means of an adiabatic calorimeter. The heat capacity data were measured in the temperature range between 5 and 375 K for 7 samples with x = 0 (pure PMMA), 0.10, 0.18, 0.27, 0.48, 0.65, and 1.0 (pure ionic liquid) where x is a mole fraction of EMITFSI. These data revealed that two broad but distinct glass transitions appeared in the low x region. The upper glass transition is mainly due to the freezing of the PMMA motion, while the lower one is due to the ionic liquid. The upper glass transition temperature T(g) drastically decreased with increasing x, reflecting a large plasticization effect observed in mechanical experiments. The x dependence of the T(g)s and the excess heat capacities gave new physical insight to the interaction between polymer and ionic liquid in ion gels.

  3. Preparation of silver-carbon nanotubes composites with plasma electrochemistry

    Science.gov (United States)

    Hoefft, Oliver; Lohmann, Lara; Olschewski, Mark; Endres, Frank

    2016-09-01

    Plasma electrochemistry is a powerful tool to generate free nanoparticles in aqueous solutions and especially in ionic liquids (ILs). Due to their very low vapour pressure, ionic liquids can be employed under vacuum conditions as fluid substrates or solvents. Thus, ionic liquids are well suitable electrolytes for plasma electrochemical processes delivering stable and homogeneous plasmas. We have shown that free copper and germanium nanoparticles can be obtained in ILs by applying a plasma as a mechanically contact-free electrode. Here we present our results using an argon plasma for the electrochemical synthesis of silver on pure and pre-treated multiwall carbon nanotubes (MWCNTs) in 1-ethyl-3-methylimidazolium dicyanamide. For the pre-treatment of the MWCNTS we have used a dielectric barrier discharge plasma (DBD) at atmospheric pressure. For the untreated MWCNTs we have found a formation of free silver nanoparticles between, on and in the vicinity of the carbon nanotubes. In case of the plasma treated MWCNTs a silver-carbon nanotubes composite is formed. Thus, the treatment of the MWCNTs obviously has a great influence on the deposit. Therefore we additionally have investigated the influence of the DBD on the chemical composition of the MWCNTs surface with X-Ray Photoelectron Spectroscopy.

  4. Antiferromagnetic ordering in magnetic ionic liquid Emim[FeCl{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Pedro, I. de, E-mail: depedrovm@unican.e [CITIMAC, Facultad de Ciencias, Universidad de Cantabria, 39005 Santander (Spain); Rojas, D.P. [CITIMAC, Facultad de Ciencias, Universidad de Cantabria, 39005 Santander (Spain); Blanco, Jesus A. [Departamento de Fisica, Universidad de Oviedo, 33007 Oviedo (Spain); Fernandez, J. Rodriguez [CITIMAC, Facultad de Ciencias, Universidad de Cantabria, 39005 Santander (Spain)

    2011-05-15

    The magnetic ionic liquids (MILs) are considered to open up a wide range of applications because of their magnetic and electrochromic switching. Until recently almost all magnetic ionic liquids containing tetrachloroferrate ion FeCl{sub 4}{sup -} evidenced a paramagnetic temperature dependence of the magnetic susceptibility, with only small deviations from the Curie law at low temperatures. However, 1-ethyl-3-methylimidazolium tetrachloroferrate, Emim[FeCl{sub 4}], clearly exhibits a long-range antiferromagnetic ordering below the Neel temperature T{sub N}{approx}3.8 K. In addition, the shape of the magnetic ordering depends on the cooling speed, indicating that the magnetic coupling could be modified. - Research highlights: Study of MILs is a new and emergent field, involving chemistry, physics, and engineering. MILs have potential applications in relation with their magnetic properties. We present for the first time a long-range magnetic ordering of an ionic liquid. The long-range magnetic ordering depends on the cooling speed.

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

    Science.gov (United States)

    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.

  6. Role of reduced precursor and solvolytic reagent molar ratio on preparation and properties of ionogel

    Science.gov (United States)

    Gupta, Abhishek Kumar; Verma, Yogendra Lal; Singh, Manish Pratap; Singh, Rajendra Kumar

    2016-10-01

    In the present study, ionogels have been synthesized by immobilizing IL (1-ethyl-3-methylimidazolium tetrafluoroborate) in silica gel matrices using non-aqueous route. In this process, tetraethyl orho-silane (TEOS) as a precursor to silicon dioxide and formic acid as a solvolytic gelating reagent in reduced molar ratio 1:4 were used. We find that reduced molar concentration of formic acid results the formation of ionogels having less number of closed pores (totally isolated from their neighbours), larger density and stable monolithic form. TEM and SEM measurements are used to visualize the morphology of sample and closed pores present in the sample. N2-sorption measurement is used to measure the pore parameters of the silica matrices which shows the mesoporous structure. DSC and TGA results show the change in phase transition temperature and thermal stability of IL upon confinement in silica matrices. Moreover, ionic conductivity of bulk and confined IL is measured using impedance spectroscopy and it has been found that it increases with increasing the temperature as well as concentration of IL in ionogels. Apart from these characterization techniques, ionogels have been characterized using FTIR and fluorescence spectroscopy which exhibit the change in vibrational frequencies and fluorescence behaviour of confined IL.

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

    Science.gov (United States)

    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).

  8. Quaternary ammonium room-temperature ionic liquid including an oxygen atom in side chain/lithium salt binary electrolytes: ab initio molecular orbital calculations of interactions between ions.

    Science.gov (United States)

    Tsuzuki, Seiji; Hayamizu, Kikuko; Seki, Shiro; Ohno, Yasutaka; Kobayashi, Yo; Miyashiro, Hajime

    2008-08-14

    Interactions of the lithium bis(trifluoromethylsulfonyl)amide (LiTFSA) complex with N, N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium (DEME), 1-ethyl-3-methylimidazolium (EMIM) cations, neutral diethylether (DEE), and the DEMETFSA complex were studied by ab initio molecular orbital calculations. An interaction energy potential calculated for the DEME cation with the LiTFSA complex has a minimum when the Li atom has contact with the oxygen atom of DEME cation, while potentials for the EMIM cation with the LiTFSA complex are always repulsive. The MP2/6-311G**//HF/6-311G** level interaction energy calculated for the DEME cation with the LiTFSA complex was -18.4 kcal/mol. The interaction energy for the neutral DEE with the LiTFSA complex was larger (-21.1 kcal/mol). The interaction energy for the DEMETFSA complex with LiTFSA complex is greater (-23.2 kcal/mol). The electrostatic and induction interactions are the major source of the attraction in the two systems. The substantial attraction between the DEME cation and the LiTFSA complex suggests that the interaction between the Li cation and the oxygen atom of DEME cation plays important roles in determining the mobility of the Li cation in DEME-based room temperature ionic liquids.

  9. Correlations between phase behaviors and ionic conductivities of (ionic liquid + alcohol) systems

    Energy Technology Data Exchange (ETDEWEB)

    Park, Nam Ku [Division of Chemical Engineering and Molecular Thermodynamics Lab, Hanyang University, Seoul 133-791 (Korea, Republic of); Bae, Young Chan, E-mail: ycbae@hanyang.ac.k [Division of Chemical Engineering and Molecular Thermodynamics Lab, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2010-11-15

    To understand the basic properties of ionic liquids (ILs), we examined the phase behavior and ionic conductivity characteristics using various compositions of different ionic liquids (1-ethyl-3-methylimidazolium hexafluorophosphate [emim; PF6] and 1-benzyl-3-methylimidazolium hexafluorophosphate [bzmim; PF6]) in several different alcohols (ethanol, propanol, 1-butanol, 2-butanol, and hexanol). We conducted a systematic study of the impact of different factors on the phase behavior of imidazolium-based ionic liquids in alcohols. Using a new experimental method with a liquid electrolyte system, we observed that the ionic conductivity of the ionic liquid/alcohol was sensitive to the surrounding temperature. We employed Chang et al.'s thermodynamic model [Chang et al. (1997, 1998) ] based on the lattice model. The obtained co-ordinated unit parameter from this model was used to describe the phase behavior and ionic conductivities of the given system. Good agreement with experimental data of various alcohol and ILs systems was obtained in the range of interest.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  12. Nano-Structural Investigation on Cellulose Highly Dissolved in Ionic Liquid: A Small Angle X-ray Scattering Study

    Directory of Open Access Journals (Sweden)

    Takatsugu Endo

    2017-01-01

    Full Text Available We investigated nano-structural changes of cellulose dissolved in 1-ethyl-3-methylimidazolium acetate—an ionic liquid (IL—using a small angle X-ray scattering (SAXS technique over the entire concentration range (0–100 mol %. Fibril structures of cellulose disappeared at 40 mol % of cellulose, which is a significantly higher concentration than the maximum concentration of dissolution (24–28 mol % previously determined in this IL. This behavior is explained by the presence of the anion bridging, whereby an anion prefers to interact with multiple OH groups of different cellulose molecules at high concentrations, discovered in our recent work. Furthermore, we observed the emergence of two aggregated nano-structures in the concentration range of 30–80 mol %. The diameter of one structure was 12–20 nm, dependent on concentration, which is ascribed to cellulose chain entanglement. In contrast, the other with 4.1 nm diameter exhibited concentration independence and is reminiscent of a cellulose microfibril, reflecting the occurrence of nanofibrillation. These results contribute to an understanding of the dissolution mechanism of cellulose in ILs. Finally, we unexpectedly proposed a novel cellulose/IL composite: the cellulose/IL mixtures of 30–50 mol % that possess liquid crystallinity are sufficiently hard to be moldable.

  13. Fractionation of sugarcane bagasse using a combined process of dilute acid and ionic liquid treatments.

    Science.gov (United States)

    Diedericks, Danie; van Rensburg, Eugéne; Görgens, Johann F

    2012-08-01

    Biorefineries processing lignocellulose will produce chemicals and fuels from chemical constituents, cellulose, hemicelluloses, and lignin to replace fossil-derived products. Fractionation of sugarcane bagasse into three pure streams of chemical constituents was addressed through dissolution of constituents with the ionic liquids, 1-ethyl-3-methylimidazolium acetate ([EMiM]CH(3)COO) or 1-butyl-3-methylimidazolium methyl sulfate ([BMiM]MeSO(4)). Constituents were isolated from the reaction mixture with the anti-solvents acetone (Ā), acetone-water (AW), and sodium hydroxide (NaOH). Delignification was enhanced by NaOH, although resulting in impure product streams. Xylose pre-extraction (75 % w/w) by dilute acid pretreatment, prior to ionic liquid treatment, improved lignin purity after anti-solvent separation. Fractionation efficiency of the combined process was maximized (84 %) by ionic liquid treatment at 125 °C for 120 min, resulting in 80.2 % (w/w) lignin removal and 76.5 % (w/w) lignin recovery. Ionic liquids achieved similar degrees of delignification, although fully digestible cellulose-rich solids were produced only by [EMiM]CH(3)COO treatment.

  14. MWCNTs/Cu(OH){sub 2} nanoparticles/IL nanocomposite modified glassy carbon electrode as a voltammetric sensor for determination of the non-steroidal anti-inflammatory drug diclofenac

    Energy Technology Data Exchange (ETDEWEB)

    Arvand, Majid, E-mail: arvand@guilan.ac.ir; Gholizadeh, Tahereh M.; Zanjanchi, Mohammad Ali

    2012-08-01

    This paper describes the development and utilization of a new nanocomposite consisting of Cu(OH){sub 2} nanoparticles, hydrophobic ionic liquid 1-ethyl-3-methylimidazolium hexafluorophosphate (EMIMPF{sub 6}) and multiwalled carbon nanotubes for glassy carbon electrode modification. The nanocomposite was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM) along with energy-dispersive X-ray spectroscopy (EDX). The modified electrode was used for electrochemical characterization of diclofenac. Using differential pulse voltammetry, the prepared sensor showed good sensitivity and selectivity with low overpotential for the determination of diclofenac in the range from 0.18 to 119 {mu}M, with a detection limit of 0.04 {mu}M. Electrochemical studies suggested that the MWCNTs/Cu(OH){sub 2} nanoparticles/IL nanocomposite modified electrode provided a synergistic augmentation on the voltammetric behavior of electrochemical oxidation of diclofenac, which was indicated by the improvement of anodic peak current. Highlights: Black-Right-Pointing-Pointer This work examines oxidation of diclofenac at a nanocomposite modified electrode. Black-Right-Pointing-Pointer The salient feature of this electrode is large diffusion coefficient. Black-Right-Pointing-Pointer The proposed electrode decreased overpotential of diclofenac electrooxidation. Black-Right-Pointing-Pointer The modified electrode has good stability and reproducibility.

  15. Polymer-ionic liquid ternary systems for Li-battery electrolytes: Molecular dynamics studies of LiTFSI in a EMIm-TFSI and PEO blend.

    Science.gov (United States)

    Costa, Luciano T; Sun, Bing; Jeschull, Fabian; Brandell, Daniel

    2015-07-14

    This paper presents atomistic molecular dynamics simulation studies of lithium bis(trifluoromethane)sulfonylimide (LiTFSI) in a blend of 1-ethyl-3-methylimidazolium (EMIm)-TFSI and poly(ethylene oxide) (PEO), which is a promising electrolyte material for Li- and Li-ion batteries. Simulations of 100 ns were performed for temperatures between 303 K and 423 K, for a Li:ether oxygen ratio of 1:16, and for PEO chains with 26 EO repeating units. Li(+) coordination and transportation were studied in the ternary electrolyte system, i.e., PEO16LiTFSI⋅1.0 EMImTFSI, by applying three different force field models and are here compared to relevant simulation and experimental data. The force fields generated significantly different results, where a scaled charge model displayed the most reasonable comparisons with previous work and overall consistency. It is generally seen that the Li cations are primarily coordinated to polymer chains and less coupled to TFSI anion. The addition of EMImTFSI in the electrolyte system enhances Li diffusion, associated to the enhanced TFSI dynamics observed when increasing the overall TFSI anion concentration in the polymer matrix.

  16. Inkjet printed organic electrochemical transistors with highly conducting polymer electrolytes

    Science.gov (United States)

    Afonso, Mónica; Morgado, Jorge; Alcácer, Luís

    2016-10-01

    Organic Electrochemical Transistors (OECTs) were fabricated with two kinds of highly conducting polymer electrolytes, one with cations of small dimensions (Li+) and the other with cations of large dimensions (1-ethyl-3-methylimidazolium, EMI+). All OECTs exhibit transconductance values in the millisiemens range. Those with the larger EMI+ cations reach higher transconductance values and the saturated region of their I(V) characteristics extends to drain negative voltages of the order of -2 V without breakdown. These OECTs aim at potential applications for which it is relevant to use a solid polymer electrolyte instead of an aqueous electrolyte, namely, for integration in complex devices or in sensors and transducers where the electrolyte film may act as a membrane to prevent direct contact of the active material (PEDOT:PSS) with the biological media. The choice of electrolytes with cations of disparate sizes aims at assessing the nature (Faradaic or capacitive) of the processes occurring at the electrolyte/channel interface. The results obtained are consistent with a Faradaic-based operation mechanism.

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

    Science.gov (United States)

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

    2013-06-20

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

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Petr Kuberský

    2015-11-01

    Full Text Available 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(trifluoromethylsulfonylimide ([EMIM][N(Tf2] 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(Tf2] 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.

  20. Structure and ionic conductivity of ionic liquid embedded PEO- LiCF3SO3 polymer electrolyte

    Directory of Open Access Journals (Sweden)

    A. Karmakar

    2014-08-01

    Full Text Available In this paper we have reported electrical and other physical properties of polyethylene oxide (PEO - LiCF3SO3 polymer electrolytes embedded with 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid. The addition of the ionic liquid to PEO- LiCF3SO3 electrolyte increases the amorphous phase content considerably and decreases the glass transition temperature. The relative amounts of different ionic species present in these electrolytes have been determined. It is observed that the fraction of free anions increase with the increase of ionic liquid concentration, whereas the fraction for ion pairs and aggregates show a decreasing trend under the same condition. The ionic conductivity of the PEO- LiCF3SO3 polymer electrolyte embedded with ionic liquid is higher than that of the PEO- LiCF3SO3 electrolyte. The ionic conductivity shows a transition around 323 K. The ionic conductivity above 323 K exhibits Arrhenius behavior with an activation energy, which decreases with the increase of ionic liquid concentration. However, below 323 K the conductivity shows Vogel–Tamman–Fulcher (VTF type behavior.

  1. Enhanced Mixed Feedstock Processing Using Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-10-22

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

  2. Study of surface interactions of ionic liquids with aluminium alloys in corrosion and erosion corrosion processes

    Science.gov (United States)

    Bermúdez, María-Dolores; Jiménez, Ana-Eva; Martínez-Nicolás, Ginés

    2007-06-01

    Surface interactions of alkylimidazolium ionic liquids (ILs) with aluminium alloy Al 2011 have been studied by immersion tests in seven neat ILs [1- n-alkyl-3-methylimidazolium X - (X = BF 4; n = 2 (IL1), 6 (IL2), 8 (IL3). X = CF 3SO 3; n = 2 (IL4). X = (4-CH 3C 6H 4SO 3); n = 2 (IL5). X = PF 6; n = 6 (IL6)] and 1-butyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide (IL7)]. Immersion tests for Al 2011 have also been carried out in 1 wt.% and 5 wt.% solutions of 1-ethyl,3-methylimidazolium tetrafluoroborate (IL1) in water. No corrosion of Al 2011 by neat ILs is observed. The highest corrosion rate for Al 2011 in water is observed in the presence of a 5 wt.% IL1 due to hydrolysis of the anion with hydrogen evolution and formation of aluminium fluoride. Erosion-corrosion processes have been studied for three aluminium alloys (Al 2011, Al 6061 and Al 7075) in a 90 wt.% IL1 solution in water in the presence of α-alumina particles. The erosion-corrosion rates are around 0.2 mm/year or lower, and increase with increasing copper content to give a corrosion resistance order of Al 6061 > Al 7075 > Al 2011. Results are discussed on the basis of scanning electron microscopy (SEM) observations, energy dispersive spectroscopy (EDS) analysis, X-ray diffraction (XRD) patterns and X-ray photoelectron spectroscopy (XPS) determinations.

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

    Science.gov (United States)

    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.

  4. A simple recovery process for biodegradable plastics accumulated in cyanobacteria treated with ionic liquids.

    Science.gov (United States)

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

    2015-02-01

    Here, we proposed a simple recovery process for poly(3-hydroxybutyrate) (PHB) accumulated in cyanobacteria by using ionic liquids (ILs), which dissolve cyanobacteria but not PHB. First, we investigated the effects of IL polarity on hydrogen-bonding receipt ability (β value) and hydrogen-bonding donating ability (α value) and evaluated the subsequent dissolution of cyanobacteria. We found that ILs having α values higher than approximately 0.4 and β values of approximately 0.9 were suitable for dissolution of cyanobacteria. In particular, 1-ethyl-3-methylimidazolium methylphosphonate ([C2mim][MeO(H)PO2]) was found to dissolve cyanobacteria components, but not PHB. Thus, we verified that PHB produced in cyanobacteria could be separated and recovered by simple filtering after dissolution of cyanobacteria in [C2mim][MeO(H)PO2]. Using this technique, more than 98 % of PHB was obtained on the filter as residues separated from cyanobacteria. Furthermore, [C2mim][MeO(H)PO2] maintained the ability to dissolve cyanobacteria after a simple recycling procedure.

  5. 3 V omni-directionally stretchable one-body supercapacitors based on a single ion-gel matrix and carbon nanotubes

    Science.gov (United States)

    Kim, Wonbin; Kim, Woong

    2016-06-01

    Stretchable supercapacitors often have laminated structures consisting of electrode, electrolyte, and supporting layers. Since the layers are likely to be composed of different materials, delamination is a major cause of failure upon stretching. In this study, we demonstrate delamination-free stretchable supercapacitors where all the component layers are prepared with a single matrix, which is composed of a polymer, poly(vinylidene fluoride-hexafluoropropylene) and an ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. Since the ionic liquid in the composite plays a role as both an electrolyte and a plasticizer, this composite can be used as an electrolyte and a supporting layer in the stretchable supercapacitor. The electrode layer can be fabricated by incorporating carbon nanotubes in the common matrix. Then, all the layers can be seamlessly fused into one body by dissolving the surface of the composite with acetone, which evaporates after the integration, leaving no borders between the layers. This one-body stretchable supercapacitor not only has high durability against repetitive stretches but also is stretchable in all directions. This feature clearly distinguishes them from conventional stretchable supercapacitors fabricated using buckled structures, which are stretchable only in one or two directions. Moreover, this supercapacitor has high cell voltage (˜3 V) owing to the ionic liquid-based gel electrolytes. Our demonstration of isotropically stretchable high-durability supercapacitors may have a great implication in the development of stretchable energy storage devices for real applications.

  6. Synthesis of free-standing carbon nanohybrid by directly growing carbon nanotubes on air-sprayed graphene oxide paper and its application in supercapacitor

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Li; Jiang, Wenchao; Yuan, Yang; Goh, Kunli; Yu, Dingshan [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459 (Singapore); Wang, Liang [School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin 300384 (China); Chen, Yuan, E-mail: chenyuan@ntu.edu.sg [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459 (Singapore)

    2015-04-15

    We report the synthesis of a free-standing two dimensional carbon nanotube (CNT)-reduced graphene oxide (rGO) hybrid by directly growing CNTs on air-sprayed GO paper. As a result of the good integration between CNTs and thermally reduced GO film during chemical vapor deposition, excellent electrical conductivity (2.6×10{sup 4} S/m), mechanical flexibility (electrical resistance only increases 1.1% after bent to 90° for 500 times) and a relatively large surface area (335.3 m{sup 2}/g) are achieved. Two-electrode supercapacitor assembled using the CNT–rGO hybrids in ionic liquid electrolyte (1-ethyl-3-methylimidazolium tetrafluoroborate) shows excellent stability upon 500 bending cycles with the gravimetric energy density measuring 23.7 Wh/kg and a power density of 2.0 kW/kg. Furthermore, it shows an impedance phase angle of −64.4° at a frequency of 120 Hz, suggesting good potentials for 120 Hz alternating current line filtering applications. - Graphical abstract: Flexible and highly conductive carbon nanotube-reduced graphene oxide nanohybrid. - Highlights: • Direct growth of carbon nanotubes by chemical vapor deposition on air-sprayed graphene oxide paper. • Two-dimensional carbon nanohybrid with excellent conductivity and mechanical flexibility. • Supercapacitor with excellent performance stability upon mechanical deformation for flexible electronics applications. • Supercapacitor with high impedance phase angle for 120 Hz alternating current line filtering applications.

  7. Community dynamics and glycoside hydrolase activities of thermophilic bacterial consortia adapted to switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Gladden, J.M.; Allgaier, M.; Miller, C.S.; Hazen, T.C.; VanderGheynst, J.S.; Hugenholtz, P.; Simmons, B.A.; Singer, S.W.

    2011-05-01

    Industrial-scale biofuel production requires robust enzymatic cocktails to produce fermentable sugars from lignocellulosic biomass. Thermophilic bacterial consortia are a potential source of cellulases and hemicellulases adapted to harsher reaction conditions than commercial fungal enzymes. Compost-derived microbial consortia were adapted to switchgrass at 60 C to develop thermophilic biomass-degrading consortia for detailed studies. Microbial community analysis using small-subunit rRNA gene amplicon pyrosequencing and short-read metagenomic sequencing demonstrated that thermophilic adaptation to switchgrass resulted in low-diversity bacterial consortia with a high abundance of bacteria related to thermophilic paenibacilli, Rhodothermus marinus, and Thermus thermophilus. At lower abundance, thermophilic Chloroflexi and an uncultivated lineage of the Gemmatimonadetes phylum were observed. Supernatants isolated from these consortia had high levels of xylanase and endoglucanase activities. Compared to commercial enzyme preparations, the endoglucanase enzymes had a higher thermotolerance and were more stable in the presence of 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]), an ionic liquid used for biomass pretreatment. The supernatants were used to saccharify [C2mim][OAc]-pretreated switchgrass at elevated temperatures (up to 80 C), demonstrating that these consortia are an excellent source of enzymes for the development of enzymatic cocktails tailored to more extreme reaction conditions.

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

    Science.gov (United States)

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

    2015-11-11

    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.

  9. 基于离子液体的聚丙烯腈/纤维素共混体系溶解与流变性能研究%Research on dissolution and rheological properties of polyacrylonitrile/cellulose solution based on ionic liquids

    Institute of Scientific and Technical Information of China (English)

    张瑞民; 李晓俊; 程春祖; 尹翠玉

    2012-01-01

    采用旋转流变仪对以1-乙基-3-甲基咪唑醋酸盐([EMIM]Ac)为溶剂的聚丙烯腈/纤维素溶液的流变性能进行了研究.结果表明,溶液表观黏度随浓度的升高而增大,但随剪切速率的增加而降低,为典型的切力变稀流体;单组分PAN溶液A黏度最低,单组分纤维素溶液F黏度最大,不同共混比溶液的黏度及对温度的依赖性均介于两纯组分PAN和纤维素Cell之间.%The ionic liquid of 1-ethyl-3-methylimidazolium chloride ( [ EMIM ] Ac ) was used to dissolve polyacrlonitrile/cellulose, and then its rheological properties was studied with rotational rheometer. The results showed that: [ EMIM ] Ac was the good solvent both for cellulose and polyacrlonitrile. Solutions presented typical shear thinner fluid, the apparent shear viscosity decreased with the increase in shear rate, and increased with the increase in solutions' concentration. Single component PAN solution A had the lowest viscosity, while, the pure cellulose solution F had the highest, and viscosity of different blend ratio and the dependency to temperature both between pure solution PAN and cellulose.

  10. 玉米秸秆在两种咪唑类离子液体中的溶解与再生%Cornstalk dissolution and regeneration in two imidazolium-based ionic liquids

    Institute of Scientific and Technical Information of China (English)

    李姗; 李增喜; 朱敏莉; 吕兴梅

    2013-01-01

    研究1-丁基-3-甲基咪唑氯盐(BmimCl)和1-乙基-3-甲基咪唑乙酸盐(EmimOAc)两种咪唑类离子液体在不同条件下对玉米秸秆的溶解和再生情况.采用傅里叶变换红外光谱(IR)、X-射线粉末衍射(XRD)、扫描电镜(SEM)热重分析(TGA)手段分析溶解前后秸秆的化学结构与结晶结构.结果表明,秸秆纤维素溶解再生后结晶度变低,热稳定性也略有降低;离子液体是秸秆的直接溶剂,秸秆在其中并未发生衍生化反应.%Dissolution of cornstalk in l-butyl-3-methylimidazolium chloride (BmimCl) and 1-ethyl-3-methylimidazolium acetate (EmimOAc) was studied. Chemical structure and crystalline form of cornstalk before and after dissolution were analyzed by means of FT-IR, TGA, SEM , and XRD. The results show that the crystallinity and thermostability of the regenerated cellulose-rich material slightly decreased after dissolution. Cornstalk directly dissolved in ionic liquids, and no derivatization reaction occurred.

  11. Excitation-energy dependence of solvation dynamics in room-temperature ionic liquids

    Science.gov (United States)

    Kim, Daekeon; Park, Sang-Won; Shim, Youngseon; Kim, Hyung J.; Jung, YounJoon

    2016-07-01

    Influence of the excitation energy of a probe solute molecule on its solvation dynamics and emission spectrum in 1-ethyl-3-methylimidazolium hexafluorophosphate (EMI+PF6-) is studied via molecular dynamics simulations using a coarse-grained model description. By exciting the probe at different energies, each with an extremely narrow distribution, ensuing solvent relaxation and its dynamic variance are monitored using the isoconfigurational ensemble method. Resulting Stokes shift function, S(t), indicates that long-time solvent relaxation becomes slower with the decreasing excitation energy and approaches the equilibrium correlation function, C(t), of solvent fluctuations. This suggests that the system excited at the red-edge of the spectrum observes linear response better than that at the blue-edge. A detailed analysis of nonequilibrium trajectories shows that the effect of initial configurations on variance of relaxation dynamics is mainly confined to short times; it reaches a maximum around 0.1 ≲ t ≲ 1 ps and diminishes as time further increases. The influence of the initial velocity distribution, on the other hand, tends to grow with time and dominates the long-time variations of dynamics. The emission spectrum shows the red-edge effect in accord with previous studies.

  12. Conducting IPN actuator/sensor for biomimetic vibrissa system

    Science.gov (United States)

    Festin, N.; Plesse, C.; Pirim, P.; Chevrot, C.; Vidal, F.

    2014-03-01

    Electroactive polymers, or EAPs, are polymers that exhibit a change in size or shape when stimulated by an electric field. The most common applications of this type of material are in actuators and sensors. One promising technology is the elaboration of electronic conducting polymers based actuators with Interpenetrating Polymer Networks (IPNs) architecture. Their many advantageous properties as low working voltage, light weight and high lifetime make them very attractive for various applications including robotics. Conducting IPNs were fabricated by oxidative polymerization of 3,4-ethylenedioxythiophene within a flexible Solid Polymer Electrolytes (SPE) combining poly(ethylene oxide) and Nitrile Butadiene Rubber. SPE mechanical properties and ionic conductivities in the presence of 1-ethyl-3- methylimidazolium bis-(trifluoromethylsulfonyl)-imide (EMITFSI) have been characterized. The presence of the elastomer within the SPE greatly improves the actuator performances. The free strain as well as the blocking force was characterized as a function of the actuator length. The sensing properties of those conducting IPNs allow their integration into a biomimetic perception prototype: a system mimicking the tactile perception of rat vibrissae.

  13. Synthesis of free-standing carbon nanohybrid by directly growing carbon nanotubes on air-sprayed graphene oxide paper and its application in supercapacitor

    Science.gov (United States)

    Wei, Li; Jiang, Wenchao; Yuan, Yang; Goh, Kunli; Yu, Dingshan; Wang, Liang; Chen, Yuan

    2015-04-01

    We report the synthesis of a free-standing two dimensional carbon nanotube (CNT)-reduced graphene oxide (rGO) hybrid by directly growing CNTs on air-sprayed GO paper. As a result of the good integration between CNTs and thermally reduced GO film during chemical vapor deposition, excellent electrical conductivity (2.6×104 S/m), mechanical flexibility (electrical resistance only increases 1.1% after bent to 90° for 500 times) and a relatively large surface area (335.3 m2/g) are achieved. Two-electrode supercapacitor assembled using the CNT-rGO hybrids in ionic liquid electrolyte (1-ethyl-3-methylimidazolium tetrafluoroborate) shows excellent stability upon 500 bending cycles with the gravimetric energy density measuring 23.7 Wh/kg and a power density of 2.0 kW/kg. Furthermore, it shows an impedance phase angle of -64.4° at a frequency of 120 Hz, suggesting good potentials for 120 Hz alternating current line filtering applications.

  14. On the interfacial behavior of ionic liquids: surface tensions and contact angles.

    Science.gov (United States)

    Restolho, José; Mata, José L; Saramago, Benilde

    2009-12-01

    In this work the liquid/vapour and the solid/liquid interfaces of a series of ionic liquids: 1-ethyl-3-methylpyridinium ethyl sulfate, [EMPy][EtSO4], 1-ethyl-3-methylimidazolium ethyl sulfate, [EMIM][EtSO4], 1-ethanol-3-methylimidazolium tetrafluoroborate, [C2OHMIM][BF4], 1-butyl-3-methylimidazolium tetrafluoroborate, [BMIM][BF4], and 1-octyl-3-methylimidazolium tetrafluoroborate, [OMIM][BF4], were investigated. The surface tension was measured in a wide temperature range, (298-453) K. The contact angles were determined on substrates of different polarities. Both on the polar (glass) and the non-polar substrates ((poly-(tetrafluoroethylene) and poly-(ethylene)), the liquids with maximum and minimum surface tensions lead, respectively, to the highest and the lowest contact angles. The dispersive, gamma(L)(d), and non-dispersive, gamma(L)(nd), components of the liquid surface tension, gamma(L), were calculated from the contact angles on the non-polar substrates using the Fowkes approach. The polarity fraction, gamma(L)(nd)/gamma(L), was compared with the polarity parameter, k, obtained from the fitting of the surface tension vs. temperature data to the Eötvös equation. Good agreement was found for the extreme cases: [OMIM][BF4] exhibits the lowest polarity and [BMIM][BF4], the highest. When compared with the polarity fractions of standard liquids considered as "polar" liquids, the ionic liquids studied may be considered as moderately polar.

  15. High-performance dye-sensitized solar cells based on solvent-free electrolytes produced from eutectic melts.

    Science.gov (United States)

    Bai, Yu; Cao, Yiming; Zhang, Jing; Wang, Mingkui; Li, Renzhi; Wang, Peng; Zakeeruddin, Shaik M; Grätzel, Michael

    2008-08-01

    Low-cost excitonic solar cells based on organic optoelectronic materials are receiving an ever-increasing amount of attention as potential alternatives to traditional inorganic photovoltaic devices. In this rapidly developing field, the dye-sensitized solar cell (DSC) has achieved so far the highest validated efficiency of 11.1% (ref. 2) and remarkable stability. However, the cells with the best performance use volatile solvents in their electrolytes, which may be prohibitive for outdoor solar panels in view of the need for robust encapsulation. Solvent-free room-temperature ionic liquids have been pursued as an attractive solution to this dilemma, and device efficiencies of over 7% were achieved by using some low-viscosity formulations containing 1-ethyl-3-methylimidazolium thiocyanate, selenocyanate, tricyanomethide or tetracyanoborate. Unfortunately, apart from tetracyanoborate, all of these low-viscosity melts proved to be unstable under prolonged thermal stress and light soaking. Here, we introduce the concept of using eutectic melts to produce solvent-free liquid redox electrolytes. Using a ternary melt in conjunction with a nanocrystalline titania film and the amphiphilic heteroleptic ruthenium complex Z907Na (ref. 10) as a sensitizer, we reach excellent stability and an unprecedented efficiency of 8.2% under air-mass 1.5 global illumination. Our results are of importance to realize large-scale outdoor applications of mesoscopic DSCs.

  16. Electrochemical horseradish peroxidase biosensor based on dextran-ionic liquid-V{sub 2}O{sub 5} nanobelt composite material modified carbon ionic liquid electrode

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Zhihong [Institute of Nano-Science and Technology Center, Huazhong Normal University, Wuhan 430079 (China); Sun Xiaoying; Wang Yan [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, 53 Zhenzhou Road, Qingdao 266042 (China); Zeng Yan [Institute of Nano-Science and Technology Center, Huazhong Normal University, Wuhan 430079 (China); Sun Wei, E-mail: sunwei_1975@public.qd.sd.cn [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, 53 Zhenzhou Road, Qingdao 266042 (China); Huang Xintang [Institute of Nano-Science and Technology Center, Huazhong Normal University, Wuhan 430079 (China)

    2010-11-01

    Direct electrochemistry of horseradish peroxidase (HRP) was realized in a dextran (De), 1-ethyl-3-methylimidazolium ethylsulphate ([EMIM]EtOSO{sub 3}) and V{sub 2}O{sub 5} nanobelt composite material modified carbon ionic liquid electrode (CILE). Spectroscopic results indicated that HRP retained its native structure in the composite. A pair of well-defined redox peaks of HRP appeared in pH 3.0 phosphate buffer solution with the formal potential of -0.213 V (vs. SCE), which was the characteristic of HRP heme Fe(III)/Fe(II) redox couple. The result was attributed to the specific characteristics of De-IL-V{sub 2}O{sub 5} nanocomposite and CILE, which promoted the direct electron transfer rate of HRP with electrode. The electrochemical parameters of HRP on the composite modified electrode were calculated and the electrocatalysis of HRP to the reduction of trichloroacetic acid (TCA) was examined. Under the optimal conditions the reduction peak current increased with TCA concentration in the range from 0.4 to 16.0 mmol L{sup -1}. The proposed electrode is valuable for the third-generation electrochemical biosensor.

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

    Science.gov (United States)

    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.

  18. Environmentally friendly technologies for obtaining high sugars concentrations from invasive woody species

    Directory of Open Access Journals (Sweden)

    Beatriz Gullón

    2015-09-01

    Full Text Available The efficient utilization and conversion of inexpensive invasive raw materials into bioethanol following a biorefinery approach is a priority in the research field of renewable fuel. With this purpose, Acacia dealbata wood samples were pretreated with 1-ethyl-3-methylimidazolium acetate under optimized conditions, and the resulting solids were employed as a substrate for enzymatic hydrolysis. Enzymatic assays were performed according to a complete factorial experimental design, in which the effects of two independent variables (liquor to solid ratio and enzyme to substrate ratio on the kinetics and yields of the xylan and cellulose saccharification were assessed. The Response Surface Methodology was employed for optimizing the experimental conditions. High sugar concentrations (around 80 g/L, and favorable polysaccharide conversions (CCG = 79.4% and XnCX = 77.9%. were predicted by the model under the selected operational conditions (6 g liquor/g substrate, 22 FPU/g. The results reported in this work compare well with other studies dealing with either other ionic liquids or classical pretreatments, using the same raw material or other woody substrates.

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

    Science.gov (United States)

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

    2014-11-04

    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.

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

    Science.gov (United States)

    Simone, Peter M; Lodge, Timothy P

    2009-12-01

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

  1. Transfer printing of thermoreversible ion gels for flexible electronics.

    Science.gov (United States)

    Lee, Keun Hyung; Zhang, Sipei; Gu, Yuanyan; Lodge, Timothy P; Frisbie, C Daniel

    2013-10-09

    Thermally assisted transfer printing was employed to pattern thin films of high capacitance ion gels on polyimide, poly(ethylene terephthalate), and SiO2 substrates. The ion gels consisted of 20 wt % block copolymer poly(styrene-b-ethylene oxide-b-styrene and 80 wt % ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethyl sulfonyl)amide. Patterning resolution was on the order of 10 μm. Importantly, ion gels containing the block polymer with short PS end blocks (3.4 kg/mol) could be transfer-printed because of thermoreversible gelation that enabled intimate gel-substrate contact at 100 °C, while gels with long PS blocks (11 kg/mol) were not printable at the same temperature due to poor wetting contact between the gel and substrates. By using printed ion gels as high-capacitance gate insulators, electrolyte-gated thin-film transistors were fabricated that operated at low voltages (<1 V) with high on/off current ratios (∼10(5)). Statistical analysis of carrier mobility, turn-on voltage, and on/off ratio for an array of printed transistors demonstrated the excellent reproducibility of the printing technique. The results show that transfer printing is an attractive route to pattern high-capacitance ion gels for flexible thin-film devices.

  2. Electroless deposition of platinum nanoparticles in room-temperature ionic liquids.

    Science.gov (United States)

    Zhang, Da; Okajima, Takeyoshi; Lu, Dalin; Ohsaka, Takeo

    2013-09-24

    The electroless deposition of Pt nanoparticles (Pt-NPs) could be carried out by dissolving potassium tetrachloroplatinate(II) (K2[PtCl4]) in 1-ethyl-3-methylimidazolium (EMI(+)) room-temperature ionic liquids (RTILs) containing bis(trifluoromethylsulfonyl) imide (NTf2(-)) or tetrafluoroborate (BF4(-)) anion and small cations, such as H(+), K(+), and Li(+). In this case, no deposition of Pt-NPs occurred in RTILs without such small cations. The formation of Pt-NPs was only observed in RTILs containing trifluoromethanesulfonimide (HNTf2) and protons at high temperature (≥80 °C) when potassium hexachloroplatinate(IV) (K2[PtCl6]) was dissolved in the RTILs. The obtained Pt-NPs gave a characteristic absorption spectrum of ultrasmall Pt-NPs. The ultrasmall and uniform Pt-NPs of ca. 1-4 nm in diameter were produced and the Pt-NPs/EMI(+)NTf2(-) dispersion was kept stably for several months without adding any additional stabilizers or capping molecules. The identified Fourier-transform patterns along the [0 1 1] zone axis were observed for the TEM images of Pt-NPs. On the basis of the results obtained, a probable mechanism of the electroless formation of Pt-NPs is discussed.

  3. Membrane manufacture for peptide separations

    KAUST Repository

    Kim, Dooli

    2016-06-07

    Nanostructured polymeric membranes are key tools in biomedical applications such as hemodialysis, protein separations, in the food industry, and drinking water supply from seawater. Despite of the success in different separation processes, membrane manufacture itself is at risk, since the most used solvents are about to be banned in many countries due to environmental and health issues. We propose for the first time the preparation of polyethersulfone membranes based on dissolution in the ionic liquid 1-ethyl-3-methylimidazolium dimethylphosphate ([EMIM]DEP). We obtained a series of membranes tailored for separation of solutes with molecular weight of 30, 5, 1.3, and 1.25 kg mol-1 with respective water permeances of 140, 65, 30 and 20 Lm-2h-1bar-1. We demonstrate their superior efficiency in the separation of complex mixtures of peptides with molecular weights in the range of 800 to 3500 gmol-1. Furthermore, the thermodynamics and kinetics of phase separation leading to the pore formation in the membranes were investigated. The rheology of the solutions and the morphology of the prepared membranes were examed and compared to those of polyethersulfone in organic solvents currently used for membrane manufacture.

  4. Highly porous polytriazole ion exchange membranes cast from solutions in non-toxic cosolvents

    KAUST Repository

    Chisca, Stefan

    2017-04-04

    The development of highly functionalized porous materials for protein separation is important for biotech processes. We report the preparation of highly porous polytriazole with sulfonic acid functionalization. The resulting ion exchange membranes are selective for protein adsorption. The starting material was a hydroxyl-functionalized polytriazole, which is an advantageous platform for further modification. The polymer was dissolved in a mixture of 1-ethyl-3-methylimidazolium acetate ([C2mim]OAc) and dimethyl carbonate (DMC), which can be both considered green solvents. The polymer solubilization was only possible due to an interesting effect of cosolvency, which is discussed, based in phase diagrams. Membranes were prepared by solution casting, followed by immersion in a non-solvent bath. We then grafted sulfone groups on the membranes, by reacting the hydroxyl groups with 1,3-propane sultone and 1,4-butane sultone. Lysozyme adsorption was successfully evaluated. Membranes modified with 1,4-butane sultone adsorbed more protein than those with 1,3-propane sultone.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Pasaribu, Marvin H., E-mail: marvin-shady88@yahoo.com; Arcana, I Made, E-mail: arcana@chem.itb.ac.id; Wahyuningrum, Deana, E-mail: deana@chem.itb.ac.id [Department of Chemistry, Faculty of Mathematics and Natural Sciences, InstitutTeknologi Bandung, Jl. Ganesha No. 10, Bandung 40132 (Indonesia)

    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)

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

    Science.gov (United States)

    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.

  8. Development and Characterization of Poly(1-vinylpyrrolidone-co-vinyl acetate Copolymer Based Polymer Electrolytes

    Directory of Open Access Journals (Sweden)

    Nurul Nadiah Sa’adun

    2014-01-01

    Full Text Available Gel polymer electrolytes (GPEs are developed using poly(1-vinylpyrrolidone-co-vinyl acetate [P(VP-co-VAc] as the host polymer, lithium bis(trifluoromethane sulfonimide [LiTFSI] as the lithium salt and ionic liquid, and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl imide [EMImTFSI] by using solution casting technique. The effect of ionic liquid on ionic conductivity is studied and the optimum ionic conductivity at room temperature is found to be 2.14 × 10−6 S cm−1 for sample containing 25 wt% of EMImTFSI. The temperature dependence of ionic conductivity from 303 K to 353 K exhibits Arrhenius plot behaviour. The thermal stability of the polymer electrolyte system is studied by using thermogravimetric analysis (TGA while the structural and morphological properties of the polymer electrolyte is studied by using Fourier transform infrared (FTIR spectroscopy and X-ray diffraction analysis (XRD, respectively.

  9. Ionic Liquid-Based Non-Aqueous Electrolytes for Nickel/Metal Hydride Batteries

    Directory of Open Access Journals (Sweden)

    Tiejun Meng

    2017-02-01

    Full Text Available The voltage of an alkaline electrolyte-based battery is often limited by the narrow electrochemical stability window of water (1.23 V. As an alternative to water, ionic liquid (IL-based electrolyte has been shown to exhibit excellent proton conducting properties and a wide electrochemical stability window, and can be used in proton conducting batteries. In this study, we used IL/acid mixtures to replace the 30 wt % KOH aqueous electrolyte in nickel/metal hydride (Ni/MH batteries, and verified the proton conducting character of these mixtures through electrochemical charge/discharge experiments. Dilution of ILs with acetic acid was found to effectively increase proton conductivity. By using 2 M acetic acid in 1-ethyl-3-methylimidazolium acetate, stable charge/discharge characteristics were obtained, including low charge/discharge overpotentials, a discharge voltage plateau at ~1.2 V, a specific capacity of 161.9 mAh·g−1, and a stable cycling performance for an AB5 metal hydride anode with a (Ni,Co,Zn(OH2 cathode.

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

    Science.gov (United States)

    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.

  11. High-Performance Aluminum-Ion Battery with CuS@C Microsphere Composite Cathode.

    Science.gov (United States)

    Wang, Shuai; Jiao, Shuqiang; Wang, Junxiang; Chen, Hao-Sen; Tian, Donghua; Lei, Haiping; Fang, Dai-Ning

    2017-01-24

    On the basis of low-cost, rich resources, and safety performance, aluminum-ion batteries have been regarded as a promising candidate for next-generation energy storage batteries in large-scale energy applications. A rechargeable aluminum-ion battery has been fabricated based on a 3D hierarchical copper sulfide (CuS) microsphere composed of nanoflakes as cathode material and room-temperature ionic liquid containing AlCl3 and 1-ethyl-3-methylimidazolium chloride ([EMIm]Cl) as electrolyte. The aluminum-ion battery with a microsphere electrode exhibits a high average discharge voltage of ∼1.0 V vs Al/AlCl4(-), reversible specific capacity of about 90 mA h g(-1) at 20 mA g(-1), and good cyclability of nearly 100% Coulombic efficiency after 100 cycles. Such remarkable electrochemical performance is attributed to the well-defined nanostructure of the cathode material facilitating the electron and ion transfer, especially for chloroaluminate ions with large size, which is desirable for aluminum-ion battery applications.

  12. 离子液体/极性聚合物固态电解质的研究%STUDY OF IONIC LIQUID/POLAR POLYMER SOLID STATE ELECTROLYTES

    Institute of Scientific and Technical Information of China (English)

    李朝晖; 高德淑; 苏光耀; 王霞瑜

    2006-01-01

    使用一种离子液体[1-乙基-3-甲基咪唑鎓四氟硼酸盐(EMIBF4)]掺杂极性聚合物-偏氟乙烯/六氟丙烯共聚物[P(VDF-HFP)],制备了固态聚合物电解质,其热分解温度达到273℃,30 C的离子电导率达到10-4S/cm数量级,对铝集流体具有较好的电化学稳定性.

  13. Biomass Pretreatment using Ionic Liquid and Glycerol Mixtures

    Science.gov (United States)

    Lynam, Joan Goerss

    Lignocellulosic biomass is a renewable, sustainable resource that can replace or supplement fossil fuels use for liquid fuels and chemicals. However, its recalcitrant structure including interwoven cellulose, hemicelluloses, and lignin biomacromolecules is challenging to deconstruct. Pretreating biomass so that it can be converted to useful liquids dominates process economics. Many pretreatment methods exist, but most require hazardous chemicals or processing conditions. Many ionic liquids (ILs), salts molten below 100°C, can be used to deconstruct lignocellulosic biomass and are less hazardous than the volatile organic compounds typically used. While effective, relatively safe, and recyclable, ILs are expensive. To reduce costs, dilution with other safe compounds is desirable, if there is no impact on deconstruction efficiency. Glycerol, a food additive, is inexpensive and becoming even more so since it is a by-product of the burgeoning biodiesel industry. Use of glycerol as an additive or diluent for ILs is extensively evaluated in this work. Rice hulls are an abundant biomass, with over 100 million tons produced per year, but with little practical use. The IL 1-ethyl-3-methylimidazolium formate ([C2mim][O2CH] or EMIM Form) when mixed with an equal amount of glycerol has been shown to be effective in pretreating rice hulls. Ambient pressure, a pretreatment temperature of 110°C, and a reaction time of three hours produced rice hulls that could be enzymatically hydrolyzed to give reasonably good glucose and xylose yields considering the recalcitrance of this silica-armored biomass. The IL [C2mim][O2CH] was also effective when mixed with an equal amount of glycerol to pretreat loblolly pine, a fast-growing softwood. Loblolly pine was pretreated at 140°C for three hours to produce a solid rich in cellulose and hemicelluloses, while a lignin-rich product could be precipitated from the IL. Similar products were obtained from pretreatment with a mixture of 75% 1

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-05-15

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

  15. 咪唑类离子液体在纤维素酶降解纤维素体系中的作用%Function of imidazolium-based ionic liquids in system of enzymatic degradation of cellulose

    Institute of Scientific and Technical Information of China (English)

    范琳; 王少君; 李坤兰

    2015-01-01

    Taking 1-ethyl-3-methylimidazolium diethyl phosphate ([Emim]DEP) and 1-ethyl-3-methylimidazolium acetate ([Emim]Ac) as research targets, the influence of the two ionic liquids (IL) on the process of enzymatic degradation of cellulose was investigated. By using ultrasound to assist ionic liquids in dissolving cellulose, [Emim]DEP and [Emim]Ac made the crystallinity of cellulose decrease to 53.6%and 62.3%respectively. In the process of enzymatic degradation of regenerated cellulose, when the dosage of IL was less than 2.0%, IL acted as promoter, and when the dosage of IL was 0.5%, the promoting effect of IL was the strongest. Enzymatic hydrolysis rate increased by 11.4% and 17.5% respectively. Under the optimal conditions (add in 0.5% IL), the enzyme activities of every enzyme in the cellulose system were measured. Ionic liquids had an obvious promoting effect on β-glucosidase, increasing enzyme activity by 120% and 87% respectively. Ionic liquids reduced inhibition of exoglucanase by cellubiose, and improved efficiency of enzymatic degradation of cellulose.%以1-乙基-3-甲基咪唑磷酸二乙酯([Emim]DEP)、1-乙基-3-甲基咪唑醋酸([Emim]Ac)为研究对象,考察两种离子液体(IL)对酶法降解纤维素过程的影响。采用超声辅助离子液体溶解纤维素,[Emim]DEP和[Emim]Ac分别使纤维素的结晶度降为53.6%和62.3%。在纤维素酶降解再生纤维素的过程中,当IL的加入量小于2.0%时,对酶解过程起促进作用,其中加入量为0.5%时,促进作用最强,酶解率分别提高了11.4%和17.5%。在最优条件下(加入0.5%IL),测量纤维素酶系中各个酶的酶活,结果表明离子液体对β-葡萄糖苷酶起到了明显的促进作用,分别使该酶酶活提高了120%和87%。离子液体降低了纤维二糖对葡聚糖外切酶的抑制作用,提高了酶解效率。

  16. Application of Ionic Liquids with Carboxyl and Aromatic Ring Conjugated Anions in Dye-Sensitized Solar Cells%阴离子为羧酸根和芳环共轭的离子液体在染料敏化太阳能电池中的应用

    Institute of Scientific and Technical Information of China (English)

    王海; 徐雪青; 史继富; 徐刚

    2013-01-01

      提出了利用p-π共轭效应设计离子液体的方法, p-π共轭效应可以有效分散阴离子的负电荷,降低离子液体中阴阳离子之间的库仑引力,以得到低粘度的离子液体.所设计的离子液体为1-乙基-3-甲基咪唑苯甲酸(EMIB)和1-乙基-3-甲基咪唑异烟酸(EMIIN)(它们的阴离子中羧酸根和芳环为p-π共轭结构),这两种离子液体都达到了较低的粘度(EMIB为42 mPa·s, EMIIN为27 mPa·s).进一步将这两种离子液体做成电解质,应用在染料敏化太阳能电池中,通过优化电解质的组成, EMIB基电解质达到了1.43 mS·cm-1的电导率和1.45×10-7 cm2·s-1的I-3的扩散系数,而EMIIN基电解质的电导率和I-3扩散系数分别为1.63 mS·cm-1和2.01×10-7 cm2·s-1,后者电导性能的提高主要和EMIIN粘度较低有关系.进一步将这两种电解质组装成电池,在300 W·m-2的光强下测得EMIB基电池和EMIIN基电池的效率分别为2.85%和4.30%.%A method of utilizing p-π conjugation effects for obtaining low-viscosity ionic liquids is presented. p-π conjugation effectively disperses anionic charge and reduces Coulombic interactions. Ionic liquids prepared in this study were 1-ethyl-3-methylimidazolium benzoate (EMIB) and 1-ethyl-3-methylimidazolium isonicotinate (EMIIN). They have carboxyl and aromatic ring p-π conjugated anions, and achieve low viscosities of 42 and 27 mPa·s, respectively. EMIB and EMIIN were employed as electrolytes, which were used to construct dye-sensitized solar cel s (DSCs). After optimizing the composition, the ionic conductivity and tri odide ionic diffusion constant for the EMIB-based electrolyte were 1.43 mS·cm-1 and 1.45 × 10-7 cm2·s-1, respectively. For the EMIIN-based electrolyte, the ionic conductivity and tri odide ionic diffusion constant were 1.63 mS·cm-1 and 2.01×10-7 cm2·s-1, respectively. These were higher than the corresponding values for the EMIB-based electrolyte because of EMIINʹs lower

  17. Nanoporous Carbide-Derived Carbon Material-Based Linear Actuators

    Directory of Open Access Journals (Sweden)

    Janno Torop

    2009-12-01

    Full Text Available Devices using electroactive polymer-supported carbon material can be exploited as alternatives to conventional electromechanical actuators in applications where electromechanical actuators have some serious deficiencies. One of the numerous examples is precise microactuators. In this paper, we show for first time the dilatometric effect in nanocomposite material actuators containing carbide-derived carbon (CDC and polytetrafluoroetylene polymer (PTFE. Transducers based on high surface area carbide-derived carbon electrode materials are suitable for short range displacement applications, because of the proportional actuation response to the charge inserted, and high Coulombic efficiency due to the EDL capacitance. The material is capable of developing stresses in the range of tens of N cm-2. The area of an actuator can be dozens of cm2, which means that forces above 100 N are achievable. The actuation mechanism is based on the interactions between the high-surface carbon and the ions of the electrolyte. Electrochemical evaluations of the four different actuators with linear (longitudinal action response are described. The actuator electrodes were made from two types of nanoporous TiC-derived carbons with surface area (SA of 1150 m2 g-1 and 1470 m2 g-1, respectively. Two kinds of electrolytes were used in actuators: 1.0 M tetraethylammonium tetrafluoroborate (TEABF4 solution in propylene carbonate and pure ionic liquid 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMITf. It was found that CDC based actuators exhibit a linear movement of about 1% in the voltage range of 0.8 V to 3.0 V at DC. The actuators with EMITf electrolyte had about 70% larger movement compared to the specimen with TEABF4 electrolyte.

  18. Molal Enthalpy of Solution of Ionic Liquid [C2mim][GaCl4

    Institute of Scientific and Technical Information of China (English)

    GUAN,Wei; LIU,Li; WANG,Caixia; YANG,Jiazhen

    2009-01-01

    An ionic liquid (IL),[C2mim][GaCl4](l-ethyl-3-methylimidazolium chlorogallate),was prepared by directly mixing 1-ethyl-3-methylimidazolium chloride ([C2mim][Cl]) and anhydrous GaCI3 with a molar ratio of 1/1 under dry argon.The molal enthalpies of solution,△sHm,of [C2mim][GaCl4],were measured over a molality range of about 0.008-0.1 mol·kg 1 by a solution reaction isoperibol calorimeter at 298.15 K.Considering the hydrolization of anion [GaCl4]- in dissolution process of the IL,a new method of determining the standard molal enthalpy of solution,△sH(⊙)m,was put forward on the basis of Pitzer's mixed electrolyte solution theory so that △sH(⊙)m = -132kJ·mol-1 and the sum of Pitzer's parameters;4β(0)GaCl + 4β(0)[C2mim].Cl + ΦGa,[C2mim]= -0.1373076,β(1)LGa,Cl + β(1)L[C2mim].C=0.3484209 were obtained.In terms of thermodynamic cycle and Glasser's theory of lattice energy for IL,the dissociation enthalpy of [GaCl4]-(g),△Hdis([GaCl4]-)≈5855 kJ·mol-1,that is enthalpy change for the reaction:[GaCl4]-(g)→Ga3+(g) +4Cl- (g),was estimated.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kruk, D. [Faculty of Mathematics and Computer Science, University of Warmia and Mazury in Olsztyn, Słoneczna 54, PL-10710 Olsztyn (Poland); Universität Bayreuth, Experimentalphysik II, 95440 Bayreuth (Germany); Meier, R.; Rössler, E. A. [Universität Bayreuth, Experimentalphysik II, 95440 Bayreuth (Germany); Rachocki, A. [Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznań (Poland); Korpała, A. [Department of Biophysics, Jagiellonian University Medical College, Łazarza 16, 31-530 Kraków, Poland and Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków (Poland); Singh, R. K. [Ionic Liquid and Solid State Ionics Laboratory, Department of Physics, Banaras Hindu University, Varanasi 221 005 (India)

    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-BF{sub 4}, 243–318 K), and 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF{sub 6}, 258–323 K). The dispersion of {sup 1}H spin-lattice relaxation rate R{sub 1}(ω) is measured in the frequency range of 10 kHz–20 MHz, and the studies are complemented by {sup 19}F spin-lattice relaxation measurements on BMIM-PF{sub 6} in the corresponding frequency range. From the {sup 1}H relaxation results self-diffusion coefficients for the cation in EMIM-SCN, BMIM-BF{sub 4}, and BMIM-PF{sub 6} are determined. This is done by performing an analysis considering all relevant intra- and intermolecular relaxation contributions to the {sup 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 R{sub 1} on square root of frequency. From the {sup 19}F relaxation both anion and cation diffusion coefficients are determined for BMIM-PF{sub 6}. 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.

  20. Size Control and Fractionation of Ionic Liquid Filled Polymersomes with Glassy and Rubbery Bilayer Membranes.

    Science.gov (United States)

    So, Soonyong; Lodge, Timothy P

    2016-05-17

    We demonstrate control over the size of ionic liquid (IL) filled polymeric vesicles (polymersomes) by three distinct methods: mechanical extrusion, cosolvent-based processing in an IL, and fractionation of polymersomes in a biphasic system of IL and water. For the representative ionic liquid (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([EMIM][TFSI])), the size and dispersity of polymersomes formed from 1,2-polybutadiene-b-poly(ethylene oxide) (PB-PEO) and polystyrene-b-poly(ethylene oxide) (PS-PEO) diblock copolymers were shown to be sensitive to assembly conditions. During mechanical extrusion through a polycarbonate membrane, the relatively larger polymersomes were broken up and reorganized into vesicles with mean size comparable to the membrane pore (100 nm radius); the distribution width also decreased significantly after only a few passes. Other routes were studied using the solvent-switch or cosolvent (CS) method, whereby the initial content of the cosolvent and the PEO block length of PS-PEO were systemically changed. The nonvolatility of the ionic liquid directly led to the desired concentration of polymersomes in the ionic liquid using a single step, without the dialysis conventionally used in aqueous systems, and the mean vesicle size depended on the amount of cosolvent employed. Finally, selective phase transfer of PS-PEO polymersomes based on size was used to extract larger polymersomes from the IL to the aqueous phase via interfacial tension controlled phase transfer. The interfacial tension between the PS membrane and the aqueous phase was varied with the concentration of sodium chloride (NaCl) in the aqueous phase; then the larger polymersomes were selectively separated to the aqueous phase due to differences in shielding of the hydrophobic core (PS) coverage by the hydrophilic corona brush (PEO). This novel fractionation is a simple separation process without any special apparatus and can help to prepare monodisperse polymersomes

  1. Permeability of Rubbery and Glassy Membranes of Ionic Liquid Filled Polymersome Nanoreactors in Water.

    Science.gov (United States)

    So, Soonyong; Yao, Letitia J; Lodge, Timothy P

    2015-12-03

    Nanoemulsion-like polymer vesicles (polymersomes) having ionic liquid interiors dispersed in water are attractive for nanoreactor applications. In a previous study, we demonstrated that small molecules could pass through rubbery polybutadiene membranes on a time scale of seconds, which is practical for chemical transformations. It is of interest to determine how sensitive the rate of transport is to temperature, particularly for membranes in the vicinity of the glass transition (Tg). In this work, the molecular exchange rate of 1-butylimidazole through glassy polystyrene (PS) bilayer membranes is investigated via pulsed field gradient nuclear magnetic resonance (PFG-NMR) over the temperature range from 25 to 70 °C. The vesicles were prepared by the cosolvent method in the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([EMIM][TFSI]), and four different polystyrene-b-poly(ethylene oxide) (PS-PEO) diblock polymers with varying PS molecular weights were examined. The vesicles were transferred from the ionic liquid to water at room temperature to form nanoemulsion solutions of polymer vesicles in water. The exchange rate of 1-butylimidazole added to the aqueous solutions was observed under equilibrium conditions at each temperature. The exchange rate decreased as the membrane thickness increased, and the exchange rate through the glassy membranes was three to four times slower than through the rubbery polybutadiene membranes under the same experimental conditions. These results demonstrate that the permeability through nanosized membranes depends on both the dimension and chemistry of membrane-forming blocks. Furthermore, the exchange rate was investigated as a function of temperature in the vicinity of the Tg of PS-PEO membranes. The exchange rate, however, is not a strong function of the temperature in the vicinity of the membrane Tg, due to a combination of the nanoscopic dimension of the membrane, and some degree of solvent

  2. Dynamics of a Room Temperature Ionic Liquid in Supported Ionic Liquid Membranes vs the Bulk Liquid: 2D IR and Polarized IR Pump-Probe Experiments.

    Science.gov (United States)

    Shin, Jae Yoon; Yamada, Steven A; Fayer, Michael D

    2017-01-11

    Supported ionic liquid membranes (SILMs) are membranes that have ionic liquids impregnated in their pores. SILMs have been proposed for advanced carbon capture materials. Two-dimensional infrared (2D IR) and polarization selective IR pump-probe (PSPP) techniques were used to investigate the dynamics of reorientation and spectral diffusion of the linear triatomic anion, SeCN(-), in poly(ether sulfone) (PES) membranes and room-temperature ionic liquid (RTIL), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EmimNTf2). The dynamics in the bulk EmimNTf2 were compared to its dynamics in the SILM samples. Two PES membranes, PES200 and PES30, have pores with average sizes, ∼300 nm and ∼100 nm, respectively. Despite the relatively large pore sizes, the measurements reveal that the reorientation of SeCN(-) and the RTIL structural fluctuations are substantially slower in the SILMs than in the bulk liquid. The complete orientational randomization, slows from 136 ps in the bulk to 513 ps in the PES30. 2D IR measurements yield three time scales for structural spectral diffusion (SSD), that is, the time evolution of the liquid structure. The slowest decay constant increases from 140 ps in the bulk to 504 ps in the PES200 and increases further to 1660 ps in the PES30. The results suggest that changes at the interface propagate out and influence the RTIL structural dynamics even more than a hundred nanometers from the polymer surface. The differences between the IL dynamics in the bulk and in the membranes suggest that studies of bulk RTIL properties may be poor guides to their use in SILMs in carbon capture applications.

  3. Applications of convolution voltammetry in electroanalytical chemistry.

    Science.gov (United States)

    Bentley, Cameron L; Bond, Alan M; Hollenkamp, Anthony F; Mahon, Peter J; Zhang, Jie

    2014-02-18

    The robustness of convolution voltammetry for determining accurate values of the diffusivity (D), bulk concentration (C(b)), and stoichiometric number of electrons (n) has been demonstrated by applying the technique to a series of electrode reactions in molecular solvents and room temperature ionic liquids (RTILs). In acetonitrile, the relatively minor contribution of nonfaradaic current facilitates analysis with macrodisk electrodes, thus moderate scan rates can be used without the need to perform background subtraction to quantify the diffusivity of iodide [D = 1.75 (±0.02) × 10(-5) cm(2) s(-1)] in this solvent. In the RTIL 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, background subtraction is necessary at a macrodisk electrode but can be avoided at a microdisk electrode, thereby simplifying the analytical procedure and allowing the diffusivity of iodide [D = 2.70 (±0.03) × 10(-7) cm(2) s(-1)] to be quantified. Use of a convolutive procedure which simultaneously allows D and nC(b) values to be determined is also demonstrated. Three conditions under which a technique of this kind may be applied are explored and are related to electroactive species which display slow dissolution kinetics, undergo a single multielectron transfer step, or contain multiple noninteracting redox centers using ferrocene in an RTIL, 1,4-dinitro-2,3,5,6-tetramethylbenzene, and an alkynylruthenium trimer, respectively, as examples. The results highlight the advantages of convolution voltammetry over steady-state techniques such as rotating disk electrode voltammetry and microdisk electrode voltammetry, as it is not restricted by the mode of diffusion (planar or radial), hence removing limitations on solvent viscosity, electrode geometry, and voltammetric scan rate.

  4. Development of glucose biosensor based on ZnO nanoparticles film and glucose oxidase-immobilized eggshell membrane

    Directory of Open Access Journals (Sweden)

    Bohari Noor Aini

    2015-06-01

    Full Text Available A novel electrochemical glucose biosensor was developed by depositing an ionic liquid (IL (e.g., 1-ethyl-3-methylimidazolium trifluoromethanesulfonate; [EMIM][Otf], ZnO nanoparticles (ZnONPs and eggshell membrane (ESM on a modified glassy carbon electrode (GCE for determination of glucose. Glucose oxidase (GOx was covalently immobilized on eggshell membrane with glutaraldehyde as a cross-linker. Methylene blue was used as a redox indicator to enhance the electron transfer capacity and to ensure stability of both the oxidized and reduced forms in the reaction of enzyme and substrate. The morphological characteristics of microstructures eggshell membranes, chitosan, GOx/ESM, GOx/ZnONPs/IL/ESM and GOx/ZnONPs-IL/CHIT were observed using scanning electron microscopy (SEM. The effects of scan rate, time and pH on the response of glucose biosensors were studied in detail. Under optimal conditions (pH 6.5, 50 s, cyclic voltammetry showed different glucose concentrations on the range of 1 × 10−12 to 0.6 M, with a detection limit of 1 × 10−13 M. The GOx/ZnONPs/IL/ESM was found to be more sensitive as compared to GOx/ZnONPs-IL/CHIT. This developed glucose biosensor detection approach has several advantages such as fast, simple and convenient method, sensitivity, low cost, eco-friendly, low concentrations and remarkable catalytic activities of current signals during glucose reaction.

  5. A Simple AIMD Approach to Derive Atomic Charges for Condensed Phase Simulation of Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y; Maginn, EJ

    2012-08-23

    The atomic charges for two ionic liquids (ILs), 1-n-butyl-3-methylimidazolium hexafluorophosphate ([BMIM] [PF6]) and 1-ethyl-3-methylimidazolium hexafluorophosphate ([EMIM][PF6]), were derived from periodic crystal phase calculations with density functional theory (DFT) and plane wave basis sets (denoted as "AIMD-c charge"). For both ILs, the total charge was found to be +/- 0.8 e for the cation and anion, respectively, due to the charge transfer between ions and polarization caused by the environment. These atomic charges were used in a force field developed within the general Amber force field framework. Using this force field, static, dynamic, and thermodynamic properties were computed for the two ILs using molecular dynamics simulation. The results were compared against results obtained using the same Amber force field but four different sets of partial charges, denoted as full charge, scaled charge, AIMD-1 charge, and AIMD-b charge, respectively. The full charge was derived from quantum chemistry calculation of isolated ions in a vacuum and resulted in a total charge of unity on each ion. The scaled charge was obtained by uniformly scaling the full charge by 0.8. AIMD-1 and AIMD-b charges were derived from liquid phase ab initio molecular dynamics simulations. The scaled charges have the same total charge on the ions as the AIMD-c charge but different distributions. It was found that simulation results not only depend on the total charge of each ion, but they are also sensitive to the charge distribution within an ion, especially for dynamic and thermodynamic properties. Overall, for the two ILs under study, the AIMD-c charge was found to predict experimental results better than the other four sets of charges, indicating that fitting charges from crystal phase DFT calculations, instead of extensive sampling of the liquid phase configurations, is a simple and reliable way to derive atomic charges for condensed phase ionic liquid simulations.

  6. Solubility of Hydrogen Sulfide and Methane in Ionic Liquids: 1-Ethy-3-methylimidazolium Trifluoromethanesulfonate and 1-Butyl-1-methylpyrrolidinium Trifluoromethanesulfonate

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung-Chul [Hannam University, Seoul (Korea, Republic of)

    2016-04-15

    Solubility data of hydrogen sulfide (H{sub 2}S) and methane (CH{sub 4}) in two kinds of ionic liquids with the same anion: 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][TfO]) and 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate ([bmpyr][TfO]) are presented at pressures up to about 30 MPa and at temperatures between 303 K and 343 K. The gas solubilities in ionic liquids were determined by measuring the bubble point pressures of the gas + ionic liquid mixtures with various compositions at different temperatures using a high-pressure equilibrium apparatus equipped with a variable-volume view cell. The H{sub 2}S solubilities in ionic liquid increased with the increase of pressure and decreased with the increase of temperature. On the other hand, the CH{sub 4} solubilities in ionic liquid increased significantly with the increase of pressure, but there was little effect of temperature on the CH{sub 4} solubility. For the ionic liquds [emim][TfO] and [bmpyr][TfO] with the same anion, the solubility of H{sub 2}S as a molality basis was substantially similar, regardless of the temperature and pressure conditions as a molar concentration basis. Comparing the solubilities of H{sub 2}S and CH{sub 4} in the ionic liquid [emim][TfO], the solubilities of H{sub 2}S were much greater than those of CH{sub 4}. For the same type of ionic liquid, the solubility data of H{sub 2}S and CH{sub 4} obtained in this study were compared to the solubility data of CO2 from the literature. When compared at the same pressure and temperature conditions, the CO{sub 2} solubility was in between the solubility of H{sub 2}S and CH{sub 4}.

  7. Ultrafast Torsional Relaxation of Thioflavin-T in Tris(pentafluoroethyl)trifluorophosphate (FAP) Anion-Based Ionic Liquids.

    Science.gov (United States)

    Singh, Prabhat K; Mora, Aruna K; Nath, Sukhendu

    2015-11-01

    Ultrafast spectroscopy on solutes, whose dynamics is very sensitive to the friction in its local environment, has strong potential to report on the microenvironment existing in complex fluids such as ionic liquids. In this work, the torsional relaxation dynamics of Thioflavin-T (ThT), an ultrafast molecular rotor, is investigated in two fluoroalkylphosphate ([FAP])-based ionic liquids, namely, 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate ([EMIM][FAP]) and 1-(2-hydroxyethyl)-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate ([OHEMIM][FAP]), using ultrafast fluorescence up-conversion spectroscopy. The emission quantum yield and the excited-state fluorescence lifetime measurement suggest that the torsional relaxation of Thioflavin-T, in this class of ionic liquids, is guided by the viscosity of the medium. The temporal profile of the dynamic Stokes' shift of ThT, measured from time-resolved emission spectrum (TRES), displays a multiexponential behavior in both ionic liquids. The long time dynamics of the Stokes' shift is reasonably slower for the hydroxyethyl derivative as compared to the ethyl derivative, which is in accordance with their measured shear viscosity. However, the short time dynamics of Stokes' shift is very similar in both the ionic liquids, and seems to be independent of the measured shear viscosity of the ionic liquid. We rationalize these observations in terms of different locations of ThT in these ionic liquids. These results suggest that despite having a higher bulk viscosity in the ionic liquid, they can provide unique microenvironment in their complex structure, where the reaction can be faster than expected from their measured shear viscosity.

  8. Soft glassy colloidal arrays in an ionic liquid: colloidal glass transition, ionic transport, and structural color in relation to microstructure.

    Science.gov (United States)

    Ueno, Kazuhide; Sano, Yuta; Inaba, Aya; Kondoh, Masashi; Watanabe, Masayoshi

    2010-10-21

    The colloidal glass transition, ionic transport, and optical properties of soft glassy colloidal arrays (SGCAs) that consist of poly(methyl methacrylate) (PMMA)-grafted silica nanoparticles (PMMA-g-NPs) and a room-temperature ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethane sulfonyl)amide ([C(2)mim][NTf(2)]), were investigated. At lower particle concentrations, PMMA-g-NPs were well-suspended in the IL without any aggregation or sedimentation, and the dilute suspensions showed liquid-like behavior. However, above a certain particle concentration, the suspensions became solidified and exhibited different structural colors depending on the particle concentrations. The liquid-solid transition of the SGCAs was essentially caused by colloidal glass transition. Due to the soft repulsive interaction between the particles, the effective volume fraction of the particle (ϕ(eff)) required for colloidal glass transition was higher than that of the hard sphere system and found to be approximately 0.70-0.74. The SGCA had sufficient ionic conductivity, which was greater than 10(-3) S cm(-1) at room temperature, even in the highly concentrated region. For ionic transport of the cation and the anion in the SGCAs, the decrease in diffusivity observed with the addition of the particles (D(g)/D(0)) was slightly greater for the [NTf(2)] anion than that of the [C(2)mim] cation, suggesting that the [NTf(2)] anion preferentially interacts with the PMMA chains. The SGCAs showed homogeneous, nonbrilliant, and angle-independent structural colors above the glass transition volume fraction. In addition, the color of the SGCAs changed from red to green to blue as the particle concentration increased. A linear relationship was found between the maximum wavelength of the reflection spectra and the center-to-center distance in the SGCAs.

  9. Development of a carbohydrate silylation method in ionic liquids for their gas chromatographic analysis.

    Science.gov (United States)

    Ruiz-Aceituno, L; Carrero-Carralero, C; Ramos, L; Martinez-Castro, I; Sanz, M L

    2013-07-17

    This paper reports on the feasibility of silylation of low molecular weight carbohydrates dissolved in different ionic liquids (ILs) for their further analysis by gas chromatography (GC). Derivatization reagents (nature and amounts), temperature and time of reaction and stirring conditions were evaluated for different carbohydrates (i.e., glucose, mannose, fructose and lactose) dissolved in 1-ethyl-3-methylimidazolium dicyanamide [EMIM][DCA]. Evaluation of conformational isomerism of glucose dissolved in [EMIM][DCA] revealed the effect of the time of dissolution in the equilibration of α- and β-furanoses (up to 3% and 6%, respectively, after 70 h of incubation) and that 21 h sufficed to obtain results similar to those provided by the reference method involving pyridine. Once optimized, the proposed derivatization procedure provided satisfactory yields (i.e., close to 100%) using 100 μL of trimethylsilylimidazole (TMSI) at mild conditions (25°C) for a relatively short time (1h) for most of the investigated carbohydrates. Under these experimental conditions, linear responses (i.e., R(2) better than 0.974) were obtained in the tested range of 0.25-1mg of the derivatized target compounds. Other reagents, such as N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA)+1% trimethylchlorosilane (TMCS), were successfully used under ultrasonic conditions for aldose monosaccharides and disaccharides derivatization, while BSTFA was useful for ketose monosaccharides. The possibility of using the proposed method for the derivatization of selected carbohydrates dissolved in different ILs and the efficiency of the method applied to the analysis of carbohydrates present in real samples (fruit juices) have also been investigated.

  10. Unusual phase separation and rheological behavior of poly(ethylene oxide)/ionic liquid mixtures with specific interactions.

    Science.gov (United States)

    Xiao, Zhilin; Larson, Ronald G; Chen, Yunlei; Zhou, Chenting; Niu, Yanhua; Li, Guangxian

    2016-09-28

    The phase separation behavior of poly(ethylene oxide) (PEO) in ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]) was investigated by rheological, optical microscopy, FT-IR and DSC measurements. It is demonstrated that specific interactions, particularly the hydrogen bonding between PEO and the ionic liquids as evidenced by FT-IR, in which a subtle but apparent absorption peak shift near the phase transition appears, account for the unusual low critical solution temperature (LCST) phase separation. Unlike the typical trend in which the storage modulus G' simply increases with temperature near the phase boundary for polymer blends without specific interaction, in our study, a novel "V-shaped" rheological response is observed, namely a dip in G' followed by an upturn, especially at low PEO concentration (<50 wt%). The magnitude of the "V" dip has heating rate and frequency dependences, while Tr (the phase transition temperature) is almost unchanged with heating rate and frequency. Upon increasing the alkyl chain length on the imidazolium ring from an ethyl to a butyl, the "V-shape" becomes more prominent and shifts to higher temperature, which is consistent with the results of FT-IR and DSC, evidently due to the stronger hydrogen bonding interaction between PEO and [BMIM][BF4] than [EMIM][BF4]. This unusual "V" dip might be tentatively ascribed to the coupling effects of the breaking of the "hydrogen bonding cage" formed between PEO chains and IL molecules and dissolution of the heterogeneous clusters as verified by FT-IR and TEM, respectively, and the following upturn is dominated by the interface formation upon phase separation.

  11. Surface coating from phosphonate ionic liquid electrolyte for the enhancement of the tribological performance of magnesium alloy.

    Science.gov (United States)

    Jiménez, Ana Eva; Rossi, Antonella; Fantauzzi, Marzia; Espinosa, Tulia; Arias-Pardilla, Joaquin; Martínez-Nicolás, Ginés; Bermúdez, María-Dolores

    2015-05-20

    A chronoamperometric method has been applied for the growth of a surface coating on AZ31B magnesium alloy, using the imidazolium alkylphosphonate room-temperature ionic liquid 1-ethyl-3-methylimidazolium ethylphosphonate ([EMIM][EtPO3H]) as electrolyte. A surface coating layer is obtained after 4 h under a constant voltage bias of -0.8 V with respect to the standard electrode. The coating nucleation and growth process correlates well with a 3D progressive mechanism. X-ray photoelectron spectrometry (XPS) analysis of [EMIM][EtPO3H] shows new P 2p and O 1s peaks after its use as electrolyte, as a consequence of reaction between the phosphonate anion and the magnesium substrate. Angle-resolved XPS (ARXPS) analysis of [EMIM][EtPO3H] did not show any change in the composition of the surface before and after chronoamperometry, since the sampling depth (1.5 nm at the highest emission angle) is larger than the cation and anion sizes (ca. 7 and 5 Å, respectively). Characterization of the coating was made by scanning electron microscopy (SEM), focussed ion beam SEM, energy dispersive X-ray spectroscopy, XPS, and ARXPS. FIB-SEM shows that the coating presents a mean thickness of 374 (±36) nm and contains magnesium and aluminum phosphates. Linear reciprocating tribological tests under variable load show that the presence of the coating can reduce friction coefficients of the coated AZ31B against steel up to 32% and wear rates up to 90%, with respect to the uncoated alloy.

  12. Gelation mechanism of tetra-armed poly(ethylene glycol) in aprotic ionic liquid containing nonvolatile proton source, protic ionic liquid.

    Science.gov (United States)

    Hashimoto, Kei; Fujii, Kenta; Nishi, Kengo; Sakai, Takamasa; Yoshimoto, Nobuko; Morita, Masayuki; Shibayama, Mitsuhiro

    2015-04-02

    We report the gelation mechanism of tetra-armed prepolymer chains in typical aprotic ionic liquid (aIL), i.e., A-B type cross-end coupling reaction of tetra-armed poly(ethylene glycol)s with amine and activated ester terminals (TetraPEG-NH2 and TetraPEG-NHS, respectively) in 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([C2mIm][TFSA]). In the ion gel system, we focused on the pH (or H(+) concentration) dependence of the gelation reaction. We thus applied the protic ionic liquid (pIL), 1-ethylimidazolium TFSA ([C2ImH][TFSA]), as a nonvolatile H(+) source, and added it into the solvent aIL. It was found that the gelation time of TetraPEG ion gel can be successfully controlled from 1 min to 3 h depending on the concentration of pIL (cpIL = 0-3 mM). This suggests that the acid-base properties of TetraPEG-NH2 showing acid-base equilibrium (-NH2 + H(+) ⇆ -NH3(+)) in the solutions play a key role in the gelation process. The acid dissociation constants, pKa's of TetraPEG-NH3(+) and C2ImH(+) (cation of pIL) in aIL were directly determined by potentiometric titration to be 16.4 and 13.7, respectively. This indicates that most of the H(+) ions bind to TetraPEG-NH2 and then C2ImH(+) exists as neutral C2Im. The reaction efficiency of amide bond (cross-linked point) systematically decreased with increasing cpIL, which was reflected to the mechanical strength of the ion gels. From these results, we discuss the gelation mechanism of TetraPEG in aIL to point out the relationship between polymer network structure and [H(+)] in the solutions.

  13. Monoenergetic source of kilodalton ions from Taylor cones of ionic liquids

    Science.gov (United States)

    Larriba, C.; Castro, S.; Fernandez de la Mora, J.; Lozano, P.

    2007-04-01

    The ionic liquid ion sources (ILISs) recently introduced by Lozano and Martinez Sanchez [J. Colloid Interface Sci. 282, 415 (2005)], based on electrochemically etched tungsten tips as emitters for Taylor cones of ionic liquids (ILs), have been tested with ionic liquids [A+B-] of increasing molecular weight and viscosity. These ILs have electrical conductivities well below 1S/m and were previously thought to be unsuitable to operate in the purely ionic regime because their Taylor cones produce mostly charged drops from conventional capillary tube sources. Strikingly, all the ILs tried on ILIS form charged beams composed exclusively of small ions and cluster ions A+(AB)n or B-(AB)n, with abundances generally peaking at n =1. Particularly interesting are the positive and negative ion beams produced from the room temperature molten salts 1-methyl-3-pentylimidazolium tris(pentafluoroethyl) trifluorophosphate (C5MI-(C2F5)3PF3) and 1-ethyl-3-methylimidazolium bis(pentafluoroethyl) sulfonylimide (EMI-(C2F5SO3)2N). We extend to these heavier species the previous conclusions from Lozano and Martinez Sanchez on the narrow energy distributions of the ion beams. In combination with suitable ILs, this source yields nanoamphere currents of positive and negative monoenergetic molecular ions with masses exceeding 2000amu. Potential applications are in biological secondary ion mass spectrometry, chemically assisted high-resolution ion beam etching, and electrical propulsion. Advantages of the ILISs versus similar liquid metal ion sources include the possibility to form negative as well as positive ion beams and a much wider range of ion compositions and molecular masses.

  14. Bioprospecting metagenomics of decaying wood: mining for new glycoside hydrolases

    Energy Technology Data Exchange (ETDEWEB)

    Li L. L.; van der Lelie D.; Taghavi, S.; McCorkle, S. M.; Zhang, Y.-B.; Blewitt, M. G.; Brunecky, R.; Adney, W. S.; Himmel, M. E.; Brumm, P.; Drinkwater, C.; Mead, D. A.; Tringe, S. G.

    2011-08-01

    To efficiently deconstruct recalcitrant plant biomass to fermentable sugars in industrial processes, biocatalysts of higher performance and lower cost are required. The genetic diversity found in the metagenomes of natural microbial biomass decay communities may harbor such enzymes. Our goal was to discover and characterize new glycoside hydrolases (GHases) from microbial biomass decay communities, especially those from unknown or never previously cultivated microorganisms. From the metagenome sequences of an anaerobic microbial community actively decaying poplar biomass, we identified approximately 4,000 GHase homologs. Based on homology to GHase families/activities of interest and the quality of the sequences, candidates were selected for full-length cloning and subsequent expression. As an alternative strategy, a metagenome expression library was constructed and screened for GHase activities. These combined efforts resulted in the cloning of four novel GHases that could be successfully expressed in Escherichia coli. Further characterization showed that two enzymes showed significant activity on p-nitrophenyl-{alpha}-L-arabinofuranoside, one enzyme had significant activity against p-nitrophenyl-{beta}-D-glucopyranoside, and one enzyme showed significant activity against p-nitrophenyl-{beta}-D-xylopyranoside. Enzymes were also tested in the presence of ionic liquids. Metagenomics provides a good resource for mining novel biomass degrading enzymes and for screening of cellulolytic enzyme activities. The four GHases that were cloned may have potential application for deconstruction of biomass pretreated with ionic liquids, as they remain active in the presence of up to 20% ionic liquid (except for 1-ethyl-3-methylimidazolium diethyl phosphate). Alternatively, ionic liquids might be used to immobilize or stabilize these enzymes for minimal solvent processing of biomass.

  15. Molecular dynamics analysis of the effect of electronic polarization on the structure and single-particle dynamics of mixtures of ionic liquids and lithium salts

    Science.gov (United States)

    Lesch, Volker; Montes-Campos, Hadrián; Méndez-Morales, Trinidad; Gallego, Luis Javier; Heuer, Andreas; Schröder, Christian; Varela, Luis M.

    2016-11-01

    We report a molecular dynamics study on the effect of electronic polarization on the structure and single-particle dynamics of mixtures of the aprotic ionic liquid 1-ethyl-3-methylimidazolium bis-(trifluoromethylsulfonyl)-imide ([EMIM][TFSI]) doped with a lithium salt with the same anion at 298 K and 1 bar. In particular, we analyze the effect of electron density fluctuations on radial distribution functions, velocity autocorrelation functions, cage correlation functions, mean-squared displacements, and vibrational densities of states, comparing the predictions of the quantum-chemistry-based Atomistic Polarizable Potential for Liquids, Electrolytes, & Polymers (APPLE&P) with those of its nonpolarizable version and those of the standard non-polarizable Optimized Potentials for Liquid Simulations-All Atom (OPLS-AA). We found that the structure of the mixture is scarcely modified by the fluctuations in electron charge of their constituents, but their transport properties are indeed quite drastically changed, with larger mobilities being predicted for the different species in the bulk mixtures with the polarizable force field. Specifically, the mean-squared displacements are larger for the polarizable potentials at identical time intervals and the intermediate subdiffusive plateaus are greatly reduced, so the transition to the diffusive regime takes place much earlier than in the non-polarizable media. Moreover, the correlations of the added cations inside their cages are weakened out earlier and their vibrational densities of states are slightly red-shifted, reflecting the weakening effect of the electronic polarization on the Coulomb coupling in these dense ionic media. The comparison of OPLS-AA with non-polarizable APPLE&P indicates that adding polarization to OPLS-AA is not sufficient to achieve results close to experiments.

  16. Electrochemical and spectroscopic study of Zn(ii) coordination and Zn electrodeposition in three ionic liquids with the trifluoromethylsulfonate anion, different imidazolium ions and their mixtures with water.

    Science.gov (United States)

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

    2015-06-28

    In this paper we report on the use of three ionic liquids, 1-methylimidazolium trifluoromethylsulfonate ([MIm]TfO), 1-ethyl-3-methylimidazolium trifluoromethylsulfonate ([EMIm]TfO) and 1-ethyl-2,3-dimethylimidazolium trifluoromethylsulfonate ([EMMIm]TfO) containing zinc trifluoromethylsulfonate as electrolytes for zinc electrodeposition. By varying the cations from [MIm](+)via [EMIm](+) to [EMMIm](+), the vibrational band in the Far-IR spectra below 200 cm(-1), characterizing the cation-anion interaction, is shifted to lower wavenumbers, which suggests that the interaction between cations and anions is arranged in order of [MIm]TfO > [EMIm]TfO > [EMMIm]TfO. The coordination of Zn(2+) ions in these electrolytes was investigated by Raman spectroscopy. The Raman spectra show obvious differences in terms of the solvation of Zn(2+) ions in the dried electrolytes. The average number of TfO(-) anions bound to each Zn(2+) ion is lower in [MIm]TfO than in [EMIm]TfO and in [EMMIm]TfO, respectively. In ionic liquid-water mixtures, aqueous zinc species were formed in all cases. The differences in zinc species present in the electrolytes should have an influence on their electrochemical behavior and on the morphology of the deposits. In dried ionic liquids, the cyclic voltammograms reveal that the potentials for the deposition of zinc were shifted to more negative values by varying the cations, while in ionic liquid-water mixtures, the deposition of zinc occurs at almost the same potential. The SEM and XRD results show that the surface morphology, crystal shape and size as well as crystallographic orientation of the deposits are markedly affected by varying the cations of the ionic liquids.

  17. Vapor pressure of ionic liquids at low temperatures from AC-chip-calorimetry.

    Science.gov (United States)

    Ahrenberg, Mathias; Beck, Martin; Neise, Christin; Keßler, Olaf; Kragl, Udo; Verevkin, Sergey P; Schick, Christoph

    2016-08-03

    The very low vapor pressure of ionic liquids is challenging to measure. At elevated temperatures the liquids might start to decompose, and at relatively low temperatures the vapor pressure becomes too low to be measured by conventional methods. In this work we developed a highly sensitive method for mass loss determination at temperatures starting from 350 K. This technique is based on an alternating current calorimeter equipped with a chip sensor that consists of a free-standing SiNx-membrane (thickness measuring area with lateral dimensions of the order of 1 mm. A small droplet (diameter ca. 600 μm) of an ionic liquid is vaporized isothermally from the chip sensor in a vacuum-chamber. The surface-to-volume-ratio of such a droplet is large and the relative mass loss due to evaporation is therefore easy to monitor by the changing heat capacity (J K(-1)) of the remaining liquid. The vapor pressure is determined from the measured mass loss rates using the Langmuir equation. The method was successfully tested for the determination of the vapor pressure and the vaporization enthalpy of an archetypical ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIm][NTf2]). The data set created in this way in an extremely broad temperature range from 358 K to 780 K has allowed the estimation of the boiling temperature of [EMIm][NTf2]. The value (1120 ± 50) K should be considered as the first reliable boiling point of the archetypical ionic liquid obtained from experimental vapor pressures measured in the most possible close proximity to the normal boiling temperature.

  18. Comparison of the local binding motifs in the imidazolium-based ionic liquids [EMIM][BF{sub 4}] and [EMMIM][BF{sub 4}] through cryogenic ion vibrational predissociation spectroscopy: Unraveling the roles of anharmonicity and intermolecular interactions

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, Joseph A.; Wolke, Conrad T.; Johnson, Christopher J.; Johnson, Mark A., E-mail: mark.johnson@yale.edu, E-mail: mccoy@chemistry.ohio-state.edu [Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520 (United States); McCoy, Anne B., E-mail: mark.johnson@yale.edu, E-mail: mccoy@chemistry.ohio-state.edu [Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210 (United States)

    2015-02-14

    We clarify the role of the critical imidazolium C{sub (2)}H position (the central C between N atoms in the heterocycle) in the assembly motif of the [EMIM][BF{sub 4}] ionic liquid by analyzing the vibrational spectra of the bare EMIM{sup +} ion as well as that of the cationic [EMIM]{sub 2}[BF{sub 4}]{sup +} (EMIM{sup +} = 1-ethyl-3-methylimidazolium, C{sub 6}H{sub 11}N{sub 2}{sup +}) cluster. Vibrational spectra of the cold, mass-selected ions are obtained using cryogenic ion vibrational predissociation of weakly bound D{sub 2} molecules formed in a 10 K ion trap. The C{sub (2)}H behavior is isolated by following the evolution of key vibrational features when the C{sub (2)} hydrogen, the proposed binding location of the anion to the imidazolium ring, is replaced by either deuterium or a methyl group (i.e., in the EMMIM{sup +} analogue). Strong features in the ring CH stretching region of the bare ion are traced to Fermi resonances with overtones of lower frequency modes. Upon incorporation into the EMIM{sup +} ⋅ ⋅ ⋅ BF{sub 4}{sup −} ⋅ ⋅ ⋅ EMIM{sup +} ternary complex, the C{sub (2)}H oscillator strength is dramatically increased, accounting for the much more complicated patterns derived from the EMIM{sup +} ring CH stretches in the light isotopomer, which are strongly suppressed in the deuterated analogue. Further changes in the spectra that occur when the C{sub (2)}H is replaced by a methyl group are consistent with BF{sub 4}{sup −} attachment directly to the imidazolium ring in an arrangement that maximizes the electrostatic interaction between the molecular ions.

  19. Dynamics of methanol in ionic liquids: validity of the Stokes-Einstein and Stokes-Einstein-Debye relations.

    Science.gov (United States)

    Herold, Elisabeth; Strauch, Matthias; Michalik, Dirk; Appelhagen, Andreas; Ludwig, Ralf

    2014-10-06

    The validity of Stokes-Einstein (SE) and Stokes-Einstein-Debye (SED) relations for methanol in the physical environment of the ionic liquid (IL) 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide is studied by means of nuclear magnetic resonance (NMR) relaxation time experiments, viscosity measurements and molecular dynamics (MD) simulations. The reorientational correlation times of the hydroxyl groups of pure methanol and of methanol in the IL/methanol mixtures were determined. For that purpose an approach for estimating NMR deuteron quadrupole coupling constants, presented by Wendt and Farrar (Mol. Phys. 1998, 95, 1077-1081), was confirmed. The self-diffusion coefficients of methanol were taken from the MD simulations. The viscosities of all systems were then measured and the SE and SED relations validated. For pure methanol both relations are valid, whereas they become increasingly invalid with increasing IL concentration, as indicated by effective volumes and radii that are too low. The deviation from the SE and SED relations could be related to dynamical heterogeneities described by the non-Gaussian parameter α(t) obtained from MD simulations. For pure methanol, α(t) is close to zero in accord with the validity of both relations. With increasing IL concentration the dynamical heterogeneities of methanol increase strongly. The times t* at the maximum of α(t) increase linearly with the relative number of methanol monomers in the mixtures. Thus, the dynamical heterogeneities are largest for single methanol molecules fully embedded in the IL environment. In their own environment methanol molecules are highly mobile, whereas in the IL-rich region the mobility is strongly reduced leading to the non-validity of SE and SED relations.

  20. Characterization of wastewater treatment plant microbial communities and the effects of carbon sources on diversity in laboratory models.

    Directory of Open Access Journals (Sweden)

    Sangwon Lee

    Full Text Available We are developing a laboratory-scale model to improve our understanding and capacity to assess the biological risks of genetically engineered bacteria and their genetic elements in the natural environment. Our hypothetical scenario concerns an industrial bioreactor failure resulting in the introduction of genetically engineered bacteria to a downstream municipal wastewater treatment plant (MWWTP. As the first step towards developing a model for this scenario, we sampled microbial communities from the aeration basin of a MWWTP at three seasonal time points. Having established a baseline for community composition, we investigated how the community changed when propagated in the laboratory, including cell culture media conditions that could provide selective pressure in future studies. Specifically, using PhyloChip 16S-rRNA-gene targeting microarrays, we compared the compositions of sampled communities to those of inocula propagated in the laboratory in simulated wastewater conditionally amended with various carbon sources (glucose, chloroacetate, D-threonine or the ionic liquid 1-ethyl-3-methylimidazolium chloride ([C2mim]Cl. Proteobacteria, Bacteroidetes, and Actinobacteria were predominant in both aeration basin and laboratory-cultured communities. Laboratory-cultured communities were enriched in γ-Proteobacteria. Enterobacteriaceae, and Aeromonadaceae were enriched by glucose, Pseudomonadaceae by chloroacetate and D-threonine, and Burkholderiacea by high (50 mM concentrations of chloroacetate. Microbial communities cultured with chloroacetate and D-threonine were more similar to sampled field communities than those cultured with glucose or [C2mim]Cl. Although observed relative richness in operational taxonomic units (OTUs was lower for laboratory cultures than for field communities, both flask and reactor systems supported phylogenetically diverse communities. These results importantly provide a foundation for laboratory models of industrial

  1. Rapid conversion of cellulose to 5-hydroxymethylfurfural using single and combined metal chloride catalysts in ionic liquid%Rapid conversion of cellulose to5-hydroxymethylfurfural using single and combined metal chloride catalysts in ionic liquid

    Institute of Scientific and Technical Information of China (English)

    Hussein Abou-Yousef; El Barbary Hassan; Philip Steele

    2013-01-01

    Direct conversion of cellulose into 5-hydroxymethylfurfural (HMF) was performed by using single or combined metal chloride catalysts in 1-ethyl-3-methylimidazolium chloride ([EMIM] Cl) ionic liquid.Our study demonstrated formation of 2-furyl hydroxymethyl ketone (FHMK),and furfural (FF) simultaneously with the formation of HMF.Various reaction parameters were addressed to optimize yields of furan derivatives produced from cellulose by varying reaction temperature,time,and the type of metal chloride catalyst.Catalytic reaction by using FeCl3 resulted in 59.9% total yield of furan derivatives (HMF,FHMK,and FF) from cellulose.CrCl3 was the most effective catalyst for selective conversion of cellulose into HMF (35.6%) with less concentrations of FHMK,and FF.Improving the yields of furans produced from cellulose could be achieved via reactions catalyzed by different combinations of two metal chlorides.Further optimization was carried out to produce total furans yield 75.9% by using FeC13/CuCl2 combination.CrCl3/CuCl2 was the most selective combination to convert cellulose into HMF (39.9%) with total yield (63.8%) of fttrans produced from the reaction.The temperature and time of the catalytic reaction played an important role in cellulose conversion,and the yields of products.Increasing the reaction temperature could enhance the cellulose conversion and HMF yield for short reaction time intervals (5 ~ 20 min).

  2. Study of surface interactions of ionic liquids with aluminium alloys in corrosion and erosion-corrosion processes

    Energy Technology Data Exchange (ETDEWEB)

    Bermudez, Maria-Dolores [Grupo de Ciencia de Materiales e Ingenieria Metalurgica, Departamento de Ingenieria de Materiales y Fabricacion, Universidad Politecnica de Cartagena, C/ Doctor Fleming s/n, Campus Muralla del Mar, 30202 Cartagena (Spain)]. E-mail: mdolores.bermudez@upct.es; Jimenez, Ana-Eva [Grupo de Ciencia de Materiales e Ingenieria Metalurgica, Departamento de Ingenieria de Materiales y Fabricacion, Universidad Politecnica de Cartagena, C/ Doctor Fleming s/n, Campus Muralla del Mar, 30202 Cartagena (Spain); Martinez-Nicolas, Gines [Grupo de Ciencia de Materiales e Ingenieria Metalurgica, Departamento de Ingenieria de Materiales y Fabricacion, Universidad Politecnica de Cartagena, C/ Doctor Fleming s/n, Campus Muralla del Mar, 30202 Cartagena (Spain)

    2007-06-30

    Surface interactions of alkylimidazolium ionic liquids (ILs) with aluminium alloy Al 2011 have been studied by immersion tests in seven neat ILs [1-n-alkyl-3-methylimidazolium X{sup -} (X = BF{sub 4}; n = 2 (IL1), 6 (IL2), 8 (IL3). X = CF{sub 3}SO{sub 3}; n = 2 (IL4). X = (4-CH{sub 3}C{sub 6}H{sub 4}SO{sub 3}); n = 2 (IL5). X PF{sub 6}; n = 6 (IL6)] and 1-butyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide (IL7)]. Immersion tests for Al 2011 have also been carried out in 1 wt.% and 5 wt.% solutions of 1-ethyl,3-methylimidazolium tetrafluoroborate (IL1) in water. No corrosion of Al 2011 by neat ILs is observed. The highest corrosion rate for Al 2011 in water is observed in the presence of a 5 wt.% IL1 due to hydrolysis of the anion with hydrogen evolution and formation of aluminium fluoride. Erosion-corrosion processes have been studied for three aluminium alloys (Al 2011, Al 6061 and Al 7075) in a 90 wt.% IL1 solution in water in the presence of {alpha}-alumina particles. The erosion-corrosion rates are around 0.2 mm/year or lower, and increase with increasing copper content to give a corrosion resistance order of Al 6061 > Al 7075 > Al 2011. Results are discussed on the basis of scanning electron microscopy (SEM) observations, energy dispersive spectroscopy (EDS) analysis, X-ray diffraction (XRD) patterns and X-ray photoelectron spectroscopy (XPS) determinations.

  3. Hierarchical micro- and mesoporous carbide-derived carbon as a high-performance electrode material in supercapacitors.

    Science.gov (United States)

    Rose, Marcus; Korenblit, Yair; Kockrick, Emanuel; Borchardt, Lars; Oschatz, Martin; Kaskel, Stefan; Yushin, Gleb

    2011-04-18

    Ordered mesoporous carbide-derived carbon (OM-CDC) materials produced by nanocasting of ordered mesoporous silica templates are characterized by a bimodal pore size distribution with a high ratio of micropores. The micropores result in outstanding adsorption capacities and the well-defined mesopores facilitate enhanced kinetics in adsorption processes. Here, for the first time, a systematic study is presented, in which the effects of synthesis temperature on the electrochemical performance of these materials in supercapacitors based on a 1 M aqueous solution of sulfuric acid and 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid are reported. Cyclic voltammetry shows the specific capacitance of the OM-CDC materials exceeds 200 F g(-1) in the aqueous electrolyte and 185 F g(-1) in the ionic liquid, when measured in a symmetric configuration in voltage ranges of up to 0.6 and 2 V, respectively. The ordered mesoporous channels in the produced OM-CDC materials serve as ion-highways and allow for very fast ionic transport into the bulk of the OM-CDC particles. At room temperature the enhanced ion transport leads to 75% and 90% of the capacitance retention at current densities in excess of ∼10 A g(-1) in ionic liquid and aqueous electrolytes, respectively. The supercapacitors based on 250-300 μm OM-CDC electrodes demonstrate an operating frequency of up to 7 Hz in aqueous electrolyte. The combination of high specific capacitance and outstanding rate capabilities of the OM-CDC materials is unmatched by state-of-the art activated carbons and strictly microporous CDC materials.

  4. 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

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Jiao [State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040 (China); Ma, Dan-Hui [College of Life Sciences, Northeast Forestry University, Harbin 150040 (China); Gai, Qing-Yan; Wang, Wei; Luo, Meng [State Engineering Laboratory of Bio-Resource Eco-Utilization, Northeast Forestry University, Harbin 150040 (China); Fu, Yu-Jie, E-mail: yujie_fu2002@yahoo.com [State Engineering Laboratory of Bio-Resource Eco-Utilization, Northeast Forestry University, Harbin 150040 (China); Ma, Wei, E-mail: mawei@hljucm.net [State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040 (China); School of Pharmaceutical, Heilongjiang University of Chinese Medicine, Harbin 150040 (China)

    2013-12-04

    Graphical abstract: -- Highlights: •A new ILAMD-HS-SDME method is developed for the microextraction of essential oil. •ILs used as destruction agent of plant cell walls and microwave absorption medium. •Parameters affecting the extraction efficiency are optimized by Box–Behnken design. •Procedure benefits: similar constituents, shorter duration and smaller sample amount. •ILAMD-HS-SDME followed by GC–MS is a promising technique in analytical fields. -- Abstract: 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 ([C{sub 2}mim]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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-04-01

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

  6. Inelastic and Reactive Scattering Dynamics of Hyperthermal Oxygen Atoms on Ionic Liquid Surfaces: [emim][NTf2] and [C12mim][NTf2

    Science.gov (United States)

    Wu, Bohan; Zhang, Jianming; Minton, Timothy K.; McKendrick, Kenneth G.; Slattery, John M.; Yockel, Scott; Schatz, George C.

    2011-05-01

    Collisions of hyperthermal oxygen atoms, with an average translational energy of 520 kJ mol-1, on continuously refreshed ionic liquids, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([emim][NTf2]) and 1-dodecyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([C12mim][NTf2]), were studied with the use of a beam-surface scattering technique. Time-of-flight and angular distributions of inelastically scattered O and reactively scattered OH and H2O were collected for various angles of incidence with the use of a rotatable mass spectrometer detector. For both O and OH, two distinct scattering processes were identified, which can be empirically categorized as thermal and non-thermal. Non-thermal scattering is more probable for both O and OH products. The observation of OH confirms that at least some reactive sites, presumably alkyl groups, must be exposed at the surface. The ionic liquid with the longer alkyl chain, [C12mim][NTf2], is substantially more reactive than the liquid with the shorter alkyl chain, [emim][NTf2], and proportionately much more so than would be predicted simply from stoichiometry based on the number of abstractable hydrogen atoms. Molecular dynamics models of these surfaces shed light on this change in reactivity. The scattering behavior of O is distinctly different from that of OH. However, no such differences between inelastic and reactive scattering dynamics have been seen in previous work on pure hydrocarbon liquids, in particular the benchmark, partially branched hydrocarbon, squalane (C30H62). The comparison between inelastic and reactive scattering dynamics indicates that inelastic scattering from the ionic liquid surfaces takes place predominantly at non-reactive sites that are effectively stiffer than the reactive alkyl chains, with a higher proportion of collisions sampling such sites for [emim][NTf2] than for [C12mim][NTf2].

  7. Polarity and Nonpolarity of Ionic Liquids Viewed from the Rotational Dynamics of Carbon Monoxide.

    Science.gov (United States)

    Yasaka, Y; Kimura, Y

    2015-12-17

    The rotational dynamics of carbon monoxide (CO) in a molten salt, ionic liquids (ILs), and alkanes were investigated by (17)O NMR T1 measurements using labeled C(17)O. The molten salt and the studied ILs have the bis(trifluoromethanesulfonyl)imide anion ([NTf2](-)) in common. In hexane near room temperature, the rotational relaxation times are close to the values predicted from the slip boundary condition in the Stokes-Einstein-Debye (SED) theory. However, in contradiction to the theoretical prediction, the rotational relaxation times decrease as the value of η/T increases, where η and T are the viscosity and absolute temperature, respectively. In other alkanes and ILs used in this study, the rotational relaxation times are much faster than those predicted by SED, and show a unique dependence on the number of alkyl carbons. For the same value of η/T, the CO rotational relaxation times in ILs composed of short-alkyl-chain-length imidazolium cations (1-ethyl-3-methylimidazolium and 1-butyl-3-methylimidazolium) are close to those for a molten salt (Cs[NTf2]). On the other hand, the rotational relaxation times in ILs composed of long-chain-length imidazolium (1-methyl-3-octylimidazolium) and phosphonium (tributylmethylphosphonium and tetraoctylphosphonium) cations are much shorter than the SED predictions. This deviation from theory increases as the alkyl chain length increases. We also found that the rotational relaxation times in dodecane and squalane are similar to those in ILs with a similar number of alkyl carbons. These results are discussed in terms of heterogeneous solvation and in comparison with the translational diffusion of CO in ILs.

  8. Galvanostatic electrodeposition of aluminium nano-rods for Li-ion three-dimensional micro-battery current collectors

    Energy Technology Data Exchange (ETDEWEB)

    Oltean, Gabriel, E-mail: gabriel.oltean@mkem.uu.s [Department of Materials Chemistry, Angstroem Laboratory, Uppsala University, Box 538, SE-751 21 Uppsala (Sweden); Nyholm, Leif; Edstroem, Kristina [Department of Materials Chemistry, Angstroem Laboratory, Uppsala University, Box 538, SE-751 21 Uppsala (Sweden)

    2011-03-30

    Research highlights: {yields} Galvanostatic electrodeposition of aluminium nano-rods. {yields} Electrodeposition in ionic liquid electrolyte. {yields} Commercial alumina membrane used as template. {yields} Current pulses allow better diffusion into the pores of the membrane. {yields} Short nucleation potential pulses result in improved homogeneity of the deposit. - Abstract: Constant current and pulsed current electrodeposition of aluminium nano-rods, for use as three-dimensional (3D) Li-ion micro-battery current collectors, have been studied using an ionic liquid electrolyte (1-ethyl-3-methylimidazolium chloride/aluminium chloride) and a template consisting of a commercial alumina membrane. It is shown that the homogeneity of the height of the rods can be improved significantly by inclusion of a short (i.e. 50 ms) potential pulse prior to the controlled current deposition step. The latter potential step increased the number of aluminium nuclei on the aluminium substrate and the best results were obtained for a potential of -0.9 V vs. Al/Al{sup 3+}. The obtained nanostructured surfaces, which were characterized using electron microscopy and X-ray diffraction, consisted of parallel aligned aluminium nano-rods homogeneously distributed over the entire surface of the substrate. A narrower height distribution for the rods was obtained using a pulsed galvanostatic approach then when using a constant current, most likely due to the less favourable diffusion conditions in the latter case. The results also indicate that depletion and iR drop effects within the nano-pores result in a more homogeneous height distribution. It is concluded that the height distribution of the nano-rods is controlled by a combination of the nucleation probability in each pore at the start of the experiment, and the homogeneity of the diameters of the pores within the commercial alumina membranes employed as the electrodeposition template.

  9. A universal model for nanoporous carbon supercapacitors applicable to diverse pore regimes, carbon materials, and electrolytes.

    Science.gov (United States)

    Huang, Jingsong; Sumpter, Bobby G; Meunier, Vincent

    2008-01-01

    Supercapacitors, commonly called electric double-layer capacitors (EDLCs), are emerging as a novel type of energy-storage device with the potential to substitute batteries in applications that require high power densities. In response to the latest experimental breakthrough in nanoporous carbon supercapacitors, we propose a heuristic theoretical model that takes pore curvature into account as a replacement for the EDLC model, which is based on a traditional parallel-plate capacitor. When the pore size is in the mesopore regime (2-50 nm), counterions enter mesoporous carbon materials and approach the pore wall to form an electric double-cylinder capacitor (EDCC); in the micropore regime (50 nm) at which pores are large enough so that pore curvature is no longer significant, the EDCC model can be reduced naturally to the EDLC model. We present density functional theory calculations and detailed analyses of available experimental data in various pore regimes, which show the significant effects of pore curvature on the supercapacitor properties of nanoporous carbon materials. It is shown that the EDCC/EWCC model is universal for carbon supercapacitors with diverse carbon materials, including activated carbon materials, template carbon materials, and novel carbide-derived carbon materials, and with diverse electrolytes, including organic electrolytes, such as tetraethylammonium tetrafluoroborate (TEABF(4)) and tetraethylammonium methylsulfonate (TEAMS) in acetonitrile, aqueous H(2)SO(4) and KOH electrolytes, and even an ionic liquid electrolyte, such as 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMI-TFSI). The EDCC/EWCC model allows the supercapacitor properties to be correlated with pore size, specific surface area, Debye length, electrolyte concentration and dielectric constant, and solute ion size It may lend support for the systematic optimization of the properties of carbon supercapacitors through experiments. On the basis of the insight

  10. Soft and flexible PEDOT/PSS films for applications to soft actuators

    Science.gov (United States)

    Li, Yuechen; Tanigawa, Ryo; Okuzaki, Hidenori

    2014-07-01

    Stretchable and highly conductive PEDOT/PSS/Xyl films were prepared by casting an aqueous dispersion of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT/PSS) as colloidal gel particles containing xylitol (Xyl) and subsequent heating. The electrical conductivity of the PEDOT/PSS/Xyl film containing 50 wt% of xylitol significantly increased from 115 S cm-1 to 407 S cm-1 by heating at 140 °C in air for 1 h. It was found that the xylitol had two functions as (i) a plasticizer to weaken hydrogen bonds between PSS of colloidal particles by replacing with that between xylitol and PSS and (ii) the additional capability of increasing the mobility of charge carriers between the colloidal particles. The transparent ionic liquid/polyurethane (IL/PU) gels were fabricated by dissolving thermoplastic polyurethane and ionic liquid of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. By increasing the IL content from 0 wt% to 70 wt%, both ionic conductivity and electric-double-layer capacitance under an electric field increased, while Young’s modulus, strength and elongation at break decreased. The IL/PU/PEDOT/PSS/Xyl composites were fabricated by sandwiching the IL/PU gel between two soft and flexible PEDOT/PSS/Xyl films. Upon application of 2 V, the IL/PU/PEDOT/PSS/Xyl composite (IL = 70%) showed quick and intensive bending toward anode, where the bending displacement at 0.1 Hz attained 2.9 mm, corresponding to the strain of 0.15%, and still worked at frequencies higher than 50 Hz.

  11. Bioprospecting metagenomics of decaying wood: mining for new glycoside hydrolases

    Directory of Open Access Journals (Sweden)

    Li Luen-Luen

    2011-08-01

    Full Text Available Abstract Background To efficiently deconstruct recalcitrant plant biomass to fermentable sugars in industrial processes, biocatalysts of higher performance and lower cost are required. The genetic diversity found in the metagenomes of natural microbial biomass decay communities may harbor such enzymes. Our goal was to discover and characterize new glycoside hydrolases (GHases from microbial biomass decay communities, especially those from unknown or never previously cultivated microorganisms. Results From the metagenome sequences of an anaerobic microbial community actively decaying poplar biomass, we identified approximately 4,000 GHase homologs. Based on homology to GHase families/activities of interest and the quality of the sequences, candidates were selected for full-length cloning and subsequent expression. As an alternative strategy, a metagenome expression library was constructed and screened for GHase activities. These combined efforts resulted in the cloning of four novel GHases that could be successfully expressed in Escherichia coli. Further characterization showed that two enzymes showed significant activity on p-nitrophenyl-α-L-arabinofuranoside, one enzyme had significant activity against p-nitrophenyl-β-D-glucopyranoside, and one enzyme showed significant activity against p-nitrophenyl-β-D-xylopyranoside. Enzymes were also tested in the presence of ionic liquids. Conclusions Metagenomics provides a good resource for mining novel biomass degrading enzymes and for screening of cellulolytic enzyme activities. The four GHases that were cloned may have potential application for deconstruction of biomass pretreated with ionic liquids, as they remain active in the presence of up to 20% ionic liquid (except for 1-ethyl-3-methylimidazolium diethyl phosphate. Alternatively, ionic liquids might be used to immobilize or stabilize these enzymes for minimal solvent processing of biomass.

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

    Science.gov (United States)

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

    2016-02-10

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

  13. Heat capacities of ionic liquids and their heats of solution in molecular liquids

    Energy Technology Data Exchange (ETDEWEB)

    Waliszewski, D. [Department of Physical Chemistry, Univesity of Lodz, PL-90 236 Lodz (Poland); Stepniak, I. [Faculty of Chemical Technology, Poznan University of Technology, PL-60 965 Poznan (Poland); Piekarski, H. [Department of Physical Chemistry, Univesity of Lodz, PL-90 236 Lodz (Poland); Lewandowski, A. [Faculty of Chemical Technology, Poznan University of Technology, PL-60 965 Poznan (Poland)]. E-mail: andrzej.lewandowski@put.poznan.pl

    2005-08-01

    Heat capacities of ionic liquids (IL): 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF{sub 4}), 1-ethyl-3-methyl imidazolium bis((trifluoromethyl)sulfonyl) imide (EMImN(CF{sub 3}SO{sub 2}){sub 2}), 1-bytyl-3-methylimidazolium tetrafluoroborate (BMImBF{sub 4}) and N,N-methyl, propyl pyrrolidinium bis((trifluoromethyl)sulfonyl) imide (MPPyN(CF{sub 3}SO{sub 2}){sub 2}) were measured from 283.15 to 358.15 K. Room temperature heat capacities have also been estimated by an additive group contribution method, based on the assumption that the heat capacity of a molecular compound equals the sum of individual atomic-group contributions. The C {sub p} {sup 293.15K} estimated values are about 12% higher than experimental values. The estimates suggest that heat capacities of ionic liquids do not differ considerably from those typical for molecular liquids (ML). The heats of solution, {delta}{sub sol} H, of ionic liquids EMImBF{sub 4}, BMImBF{sub 4} EMImN(CF{sub 3}SO{sub 2}){sub 2} and MPPyN(CF{sub 3}SO{sub 2}){sub 2} were measured in water, acetonitrile (AN) and methanol, as a function of ionic liquid concentration c {sub m}. The measured {delta}{sub sol} H values decrease with decreasing c {sub m}. Enthalpies of ionic liquid transfer, {delta}{sub t} H deg., from water to methanol and acetonitrile were calculated from measured solution enthalpies. Values of {delta}{sub t} H deg. for the transfer from water to methanol are positive and those for the transfer to acetonitrile are negative.

  14. Nitrogen-doped carbon nanofoam derived from amino acid chelate complex for supercapacitor applications

    Science.gov (United States)

    Ramakrishnan, Prakash; Shanmugam, Sangaraju

    2016-06-01

    We report a novel strategy to fabricate the nitrogen-doped mesoporous carbon nanofoam structures (N-MCNF), derived from magnesium amino acid chelate complex (Mg-acc-complex) for its application towards high performance supercapacitor (SCs) system. A series of N-MCNF with well-connected carbon nanofoam structure have been developed by varying the synthesis temperature. The fabricated N-MCNF material possesses a high surface area (1564 m2 g-1) and pore volume (1.767 cm3 g-1) with nitrogen content of 3.42 wt%. A prototypical coin cell type symmetric N-MCNF SC device has been assembled with 1-ethyl-3-methylimidazolium tetrafluoroborate [EMIMBF4] ionic liquid electrolyte, and evaluated for SCs studies. The N-MCNF with high textural properties delivers unprecedented SC performance, such as high specific capacitance (204 Fg-1 at 0.25 Ag-1, 25 °C), high energy density (63.4 Wh kg-1), high power density (35.9 kW kg-1) and long-term cycle life (32,500 cycles). Significantly, N-MCNF materials exhibited high power rate performance, at 500 mV-1 (115 Fg-1) and 25 Ag-1 (166 Fg-1) owing to the uniform mesopore size distribution (∼4 nm). The N-MCNF SC device delivered maximum energy densities of 83.4 and 93.3 Wh kg-1 at 60 °C and 90 °C, respectively. Such outstanding N-MCNF SC device is successfully demonstrated in solar energy harvester applications.

  15. Improved activity of a thermophilic cellulase, Cel5A, from Thermotoga maritima on ionic liquid pretreated switchgrass.

    Directory of Open Access Journals (Sweden)

    Zhiwei Chen

    Full Text Available Ionic liquid pretreatment of biomass has been shown to greatly reduce the recalcitrance of lignocellulosic biomass, resulting in improved sugar yields after enzymatic saccharification. However, even under these improved saccharification conditions the cost of enzymes still represents a significant proportion of the total cost of producing sugars and ultimately fuels from lignocellulosic biomass. Much of the high cost of enzymes is due to the low catalytic efficiency and stability of lignocellulolytic enzymes, especially cellulases, under conditions that include high temperatures and the presence of residual pretreatment chemicals, such as acids, organic solvents, bases, or ionic liquids. Improving the efficiency of the saccharification process on ionic liquid pretreated biomass will facilitate reduced enzyme loading and cost. Thermophilic cellulases have been shown to be stable and active in ionic liquids but their activity is typically at lower levels. Cel5A_Tma, a thermophilic endoglucanase from Thermotoga maritima, is highly active on cellulosic substrates and is stable in ionic liquid environments. Here, our motivation was to engineer mutants of Cel5A_Tma with higher activity on 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc] pretreated biomass. We developed a robotic platform to screen a random mutagenesis library of Cel5A_Tma. Twelve mutants with 25-42% improvement in specific activity on carboxymethyl cellulose and up to 30% improvement on ionic-liquid pretreated switchgrass were successfully isolated and characterized from a library of twenty thousand variants. Interestingly, most of the mutations in the improved variants are located distally to the active site on the protein surface and are not directly involved with substrate binding.

  16. SO(2) saturation of the room temperature ionic liquid [C(2)mim][NTf(2)] much reduces the activation energy for diffusion.

    Science.gov (United States)

    Barrosse-Antle, Laura E; Hardacre, Christopher; Compton, Richard G

    2009-01-29

    The physical effect of high concentrations of reversibly dissolved SO(2) on [C(2)mim][NTf(2)] was examined using cyclic voltammetry, chronoamperometry, and ESR spectroscopy. Cyclic voltammetry of the oxidation of solutions of ferrocene, N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD), and chloride in the room temperature ionic liquid (RTIL) 1-ethyl-3-methylimidazolium bis(trifluoromethanesufonyl)imide ([C(2)mim][NTf(2)]) reveals an increase in limiting current of each species corresponding to the addition of increasing concentrations of sulfur dioxide. Quantitative chronoamperometry reveals an increase in each species' diffusion coefficient with SO(2) concentration. When chronoamperometric data were obtained for ferrocene in [C(2)mim][NTf(2)] at a range of temperatures, the translational diffusion activation energy (29.0 +/- 0.5 kJ mol(- 1)) was found to be in good agreement with previous studies. Adding SO(2) results in apparent near-activationless translational diffusion. A significant decrease in the activation energy of rotational diffusion with the SO(2) saturation of a 2,2,6,6-tetramethyl-1-piperidinyloxyl (TEMPO) solution in [C(2)mim][NTf(2)] (29.9 +/- 2.0 to 7.7 +/- 5.3 kJ mol(- 1)) was observed using electron spin resonance (ESR) spectroscopy. The reversible physical absorption of SO(2) by [C(2)mim][NTf(2)] should have no adverse effect on the ability of that ionic liquid to be employed as a solvent in an electrochemical gas sensor, and it is possible that the SO(2)-mediated reduction of RTIL viscosity could have intrinsic utility.

  17. Atomistic Simulation and Electronic Structure of Lithium Doped Ionic Liquids: Structure, Transport, and Electrochemical Stability

    Science.gov (United States)

    Haskins, Justin B.; Bauschlicher, Charles W.; Lawson, John W.

    2015-01-01

    Zero-temperature density functional theory (DFT), density functional theory molecular dynamics (DFT-MD), and classical molecular dynamics using polarizable force fields (PFF-MD) are employed to evaluate the influence of Lithium ion on the structure, transport, and electrochemical stability of three potential ionic liquid electrolytes: N--methyl-N-butylpyrrolidinium bis(trifluoromethanesulfonyl)imide ([pyr14][TFSI]), N--methyl-N-propylpyrrolidinium bis(fluorosulfonyl)imide ([pyr13][FSI]), and 1-ethyl-3--methylimidazolium boron tetrafluoride ([EMIM][BF4]). We characterize the Lithium ion solvation shell through zero-temperature DFT simulations of [Li(Anion)sub n](exp n-1) -clusters, DFT-MD simulations of isolated lithium ions in small ionic liquid systems, and PFF-MD simulations with high Li-doping levels in large ionic liquid systems. At low levels of Li-salt doping, highly stable solvation shells having 2-3 anions are seen in both [pyr14][TFSI] and [pyr13][FSI], while solvation shells with 4 anions dominate in [EMIM][BF sub 4]. At higher levels of doping, we find the formation of complex Li-network structures that increase the frequency of 4 anion-coordinated solvation shells. A comparison of computational and experimental Raman spectra for a wide range of [Li(Anion) sub n](exp n -1) - clusters shows that our proposed structures are consistent with experiment. We estimate the ion diffusion coefficients and quantify both size and simulation time effects. We find estimates of lithium ion diffusion are a reasonable order of magnitude and can be corrected for simulation time effects. Simulation size, on the other hand, is also important, with diffusion coefficients from long PFF-MD simulations of small cells having 20-40% error compared to large-cell values. Finally, we compute the electrochemical window using differences in electronic energy levels of both isolated cation/anion pairs and small ionic liquid systems with Li-salt doping. The single pair and liquid

  18. Ionothermal synthesis and electrochemical analysis of Fe doped LiMnPO{sub 4}/C composites as cathode materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xueliang, E-mail: xueliangli2005@163.com; Liu, Shuai; Jin, Hongchang; Meng, Yu; Liu, Yunfu

    2014-11-25

    Highlights: • LiMn{sub 0.95}Fe{sub 0.05}PO{sub 4} particles prepared by ionothermal synthesis method are effective. • The effect of the properties of [EMIM]OTf and [BMIM]OTf in ionothermal synthesis is studied. • The obtained LiMn{sub 0.95}Fe{sub 0.05}PO{sub 4}/C exhibit shuttle shape and favorable electrochemical properties. - Abstract: Shuttle shaped and Fe doped LiMnPO{sub 4} particles are successfully synthesized via an ionothermal routine in 1-ethyl-3-methylimidazolium trifluoromethanesulfonate [EMIM]OTf and 1-buty-3-methylimidazolium trifluoromethanesulfonate [BMIM]OTf at 260 °C, respectively. And then, the carbon coated product of cathode materials can be efficiently prepared by a subsequent short calcination process. Scanning electron microscopy and field emission transmission electron microscopy shows that these as-prepared particles with the mean width of about 200 nm and length of 800 nm were coated by uniform carbon layers, which could improve the electronic conductivity of the final product effectively. The D{sub Li} values of samples that prepared in two ionic liquids above were calculated to be 1.36 × 10{sup −13} and 4.61 × 10{sup −14} cm{sup 2} s{sup −1}, respectively. It can be attributed to the LiMn{sub 0.95}Fe{sub 0.05}PO{sub 4}/C particles prepared in [BMIM]OTf present more uniform distribution and smaller size. Thus, it deliver high discharge capacities of 159.2, 146.0, 135.1, 125.3, 115.5 and 84.4 mA h g{sup −1} in the voltage range of 2.5–4.5 V at charge–discharge rate of 0.1, 0.2, 0.5, 1, 2 and 5 C, respectively.

  19. High-flux Thin-film Nanofibrous Composite Ultrafiltration Membranes Containing Cellulose Barrier Layer

    Energy Technology Data Exchange (ETDEWEB)

    Ma, H.; Yoon, K; Rong, L; Mao, Y; Mo, Z; Fang, D; Hollander, Z; Gaiteri, J; Hsiao , B; Chu, B

    2010-01-01

    A novel class of thin-film nanofibrous composite (TFNC) membrane consisting of a cellulose barrier layer, a nanofibrous mid-layer scaffold, and a melt-blown non-woven substrate was successfully fabricated and tested as an ultrafiltration (UF) filter to separate an emulsified oil and water mixture, a model bilge water for on-board ship bilge water purification. Two ionic liquids: 1-butyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazolium acetate, were chosen as the solvent to dissolve cellulose under mild conditions. The regenerated cellulose barrier layer exhibited less crystallinity (determined by wide-angle X-ray diffraction, WAXD) than the original cotton linter pulps, but good thermal stability (determined by thermal gravimetric analysis, TGA). The morphology, water permeation, and mechanical stability of the chosen TFNCmembranes were thoroughly investigated. The results indicated that the polyacrylonitrile (PAN) nanofibrous scaffold was partially imbedded in the cellulose barrier layer, which enhanced the mechanical strength of the top barrier layer. The permeation flux of the cellulose-based TFNCmembrane was significantly higher (e.g. 10x) than comparable commercial UFmembranes (PAN10 and PAN400, Sepro) with similar rejection ratios for separation of oil/water emulsions. The molecular weight cut-off (MWCO) of TFNC membranes with cellulose barrier layer was evaluated using dextran feed solutions. The rejection was found to be higher than 90% with a dextran molecular weight of 2000 KDa, implying that the nominal pore size of the membrane was less than 50 nm. High permeation flux was also observed in the filtration of an emulsified oil/water mixture as well as of a sodium alginate aqueous solution, while high rejection ratio (above 99.5%) was maintained after prolonged operation. A variation of the barrier layer thickness could dramatically affect the permeation flux and the rejection ratio of the TFNCmembranes, while different sources of cellulose

  20. Thermodynamic studies of ionic hydration and interactions for amino acid ionic liquids in aqueous solutions at 298.15 K.

    Science.gov (United States)

    Dagade, Dilip H; Madkar, Kavita R; Shinde, Sandeep P; Barge, Seema S

    2013-01-31

    Amino acid ionic liquids are a special class of ionic liquids due to their unique acid-base behavior, biological significance, and applications in different fields such as templates in synthetic chemistry, stabilizers for biological macromolecules, etc. The physicochemical properties of these ionic liquids can easily be altered by making the different combinations of amino acids as anion along with possible cation modification which makes amino acid ionic liquids more suitable to understand the different kinds of molecular and ionic interactions with sufficient depth so that they can provide fruitful information for a molecular level understanding of more complicated biological processes. In this context, volumetric and osmotic coefficient measurements for aqueous solutions containing 1-ethyl-3-methylimidazolium ([Emim]) based amino acid ionic liquids of glycine, alanine, valine, leucine, and isoleucine are reported at 298.15 K. From experimental osmotic coefficient data, mean molal activity coefficients of ionic liquids were estimated and analyzed using the Debye-Hückel and Pitzer models. The hydration numbers of ionic liquids in aqueous solutions were obtained using activity data. Pitzer ion interaction parameters are estimated and compared with other electrolytes reported in the literature. The nonelectrolyte contribution to the aqueous solutions containing ionic liquids was studied by calculating the osmotic second virial coefficient through an application of the McMillan-Mayer theory of solution. It has been found that the second osmotic virial coefficient which includes volume effects correlates linearly with the Pitzer ion interaction parameter estimated independently from osmotic data as well as the hydrophobicity of ionic liquids. The enthalpy-entropy compensation effect, explained using the Starikov-Nordén model of enthalpy-entropy compensation, and partial molar entropy analysis for aqueous [Emim][Gly] solutions are made by using experimental Gibb

  1. Ultrasonicwave-assisted extraction of lycopene from fresh tomato with ionic liquid%离子液体在番茄红素提取中的应用研究

    Institute of Scientific and Technical Information of China (English)

    崔萌; 胡乐根; 马停停; 蔡明建; 王秀阁

    2012-01-01

    以1-丁基-3-甲基咪唑四氟硼酸盐([Bmim]BF4)、1-丁基-3-甲基咪唑六氟磷酸盐([Bmim]PF6)、1-乙基-3-甲基咪唑四氟硼酸盐([Emim]BF4)、1-乙基-3-甲基溴盐([Emim]Br)、1-丁基-3-甲基咪唑硫酸一氢盐([Bmim]HSO4)离子液体为萃取剂,并用超声波辅助萃取新鲜番茄中的番茄红素.对离子液体超声波辅助萃取新鲜番茄中的番茄红素的条件进行了优化,优化后的提取条件为:以[Bmim]BF4为萃取溶剂,离子液体浓度:V乙醇/V[Bmim]BF4=3,在固定超声温度为40℃,超声萃取时间10min,超声波功率380W,料液比1:5 (g/mL)时,效果最佳.%Applying the ionic liquids, 1-butyl-3-methylimidazolium tetrafluoroborat ([ Bmim] BF4 ) , 1-butyl-3-methylimidazolium hexafluorophosphate( [Bmim]PF6) ,1-ethyl-3-methylimidazolium tetrafluoroborat( [Emim] BF4) ,1-butyl-3-methylimidazolium bro-mide( [Emim]Br) ,and 1-butyl-3-methylimizolium hydrosulfate( [Bmim]HSO4)as solvents,the ultrasonicwave-assisted solvent extraction of lycopene from fresh tomato were investigated, and the influences of extraction parameters on the extraction yield were discussed. The optimal operating conditions for ultrasonicwave-assisted extraction of lycopene with ionic liquid as solvent was obtained as follows;the suitable solvent used was[Bmim]BF4 with concentration of Vethanol/V[Bmin]BF = 3, ultrasonic temperature was fixed to ,the ultrasonic extraction time was 10 min and the ultrasonicwave power was 380 W.then the extraction effect was excellent

  2. 离子热法合成沸石咪唑骨架材料及其溶解-结晶机理研究%Ionothermal synthesis of zeolitic imidazolate frameworks and the synthesis dissolution-crystallization mechanism

    Institute of Scientific and Technical Information of China (English)

    王亚松; 徐云鹏; 李大伟; 刘浩; 厉晓蕾; 陶硕; 田志坚

    2015-01-01

    A cooling-induced crystallization process was used to synthesize sod (RCSR symbol)-and zni (RCSR symbol)-type zeolitic imidazolate frameworks (ZIFs) ionothermally in 1-ethyl-3-methylimidazolium bromide ionic liquid and a urea-choline chloride deep eutectic solvent. The products were charac-terized by X-ray diffraction, scanning electron microscopy, nuclear magnetic resonance spectrosco-py, infrared spectroscopy and thermal gravimetric analysis. The effect of the synthesis conditions on the crystallinity, size and morphology of the product was studied. The dissolution-crystallization mechanism of ZIFs was discussed. The cooling rate affected the product morphology. When the synthesis solution was cooled by rapid cooling, the shape of the sod-type product was spherical and the morphology of the zni-type product was rod-like or plate-like. With a programmed cooling, the sod-type product was polyhedron in shape and the zni-type product was in the form of clusters.%基于沸石咪唑骨架材料在离子液体和低共熔溶剂中冷却结晶的析出方式,开发了一种离子热法合成沸石咪唑骨架材料的新途径,采用X射线衍射、扫描电镜、核磁共振光谱、红外光谱以及热重分析等方法对制备的产物进行了表征,研究了合成条件对产物结晶度、尺寸和形貌的影响,探讨了沸石咪唑骨架材料在离子热合成体系中的溶解-结晶析出机理。研究发现,冷却速率能够影响产物形貌,急速冷却时, sod (RCSR代码)型产物的形貌为球形, zni (RCSR代码)型产物为棒状或平板状;程序控制冷却时, sod型产物的形貌为多面体, zni型产物呈团簇状。

  3. An advance process of aluminum rich coating as tritium permeation barrier on 321 steel workpiece

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, G.K., E-mail: Guikaizhang712@163.com [China Academy of Engineering Physics, Mianyang, 621900 (China) and College of Nuclear Science and Technology, University of Science and Technology of China, Hefei, 230026 (China); Chen, C.A.; Luo, D.L. [China Academy of Engineering Physics, Mianyang, 621900 (China); Wang, X.L. [China Academy of Engineering Physics, Mianyang, 621900 (China); College of Nuclear Science and Technology, University of Science and Technology of China, Hefei, 230026 (China)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer An advance process of tritium permeation barrier was applied to 321 steel workpiece. Black-Right-Pointing-Pointer Tritium permeation barrier consisted of an outer Al{sub 2}O{sub 3} layer and an inner FeAl alloy layer. Black-Right-Pointing-Pointer Deuterium permeation reduction factor of coated piece increased by 2 orders of magnitude. Black-Right-Pointing-Pointer Tritium permeation barriers were flexibly achieved in high reproducibility. - Abstract: We have proposed an advance three-step process, Al-electroplating in ionic liquid followed by heat treating and selectively oxidation, preparing aluminum rich coating as tritium permeation barrier (TPB). In present work, the advance process was applied to 321 steel workpieces. In the Al-electroplating, pieces were coated by galvanostatic electrodeposition at 20 mA/cm{sup 2} in aluminum chloride (AlCl{sub 3})-1-ethyl-3-methylimidazolium chloride (EMIC) ionic liquid. The Al coating on those pieces all displayed attractive brightness and well adhered to surface of pieces. Within the aluminizing time from 1 to 30 h, a series of experiments were carried out to aluminize 321 steel pieces with Al 20 {mu}m coating at 700 Degree-Sign C. After heat treated for 8 h, a 30 {mu}m thick aluminized coating on piece appeared homogeneous, free of porosity, and mainly consisted of (Fe, Cr, Ni)Al{sub 2}, and then was selectively oxidized in argon gas at 700 Degree-Sign C for 50 h to form Al{sub 2}O{sub 3} scale. The finally fabricated aluminum rich coating, without any visible defects, had a double-layered structure consisting of an outer {gamma}-Al{sub 2}O{sub 3} layer with thickness of 0.2 {mu}m and inner (Fe, Cr, Ni)Al/(Fe, Cr, Ni){sub 3}Al layer of 50 {mu}m thickness. The deuterium permeation reduction factor, PRF, of piece ({Phi} 80 Multiplication-Sign 2, L 150 mm) with such coating increased by 2 orders of magnitude at 600-727 Degree-Sign C. The reproducibility of the process was also showed.

  4. Phase behaviour and conductivity of supporting electrolytes in supercritical difluoromethane and 1,1-difluoroethane.

    Science.gov (United States)

    Han, Xue; Ke, Jie; Suleiman, Norhidayah; Levason, William; Pugh, David; Zhang, Wenjian; Reid, Gillian; Licence, Peter; George, Michael W

    2016-06-01

    We present investigations into a variety of supporting electrolytes and supercritical fluids probing the phase and conductivity behaviour of these systems and show that they not only provide sufficient electrical conductivity for an electrodeposition bath, but match the requirements imposed by the different precursors and process parameters, e.g. increased temperature, for potential deposition experiments. The two supercritical fluids that have been explored in this study are difluoromethane (CH2F2) and 1,1-difluoroethane (CHF2CH3). For CH2F2, the phase behaviour and electrical conductivity of eight ionic compounds have been studied. Each compound consists of a cation and an anion from the selected candidates i.e. tetramethylammonium ([N(CH3)4](+)), tetrabutylammonium ([N((n)C4H9)4](+)), 1-ethyl-3-methylimidazolium ([EMIM](+)) and 1-butyl-3-methylimidazolium ([BMIM](+)) for cations, and tetrakis(perfluoro-tert-butoxy)aluminate ([Al(OC(CF3)3)4](-)), chloride (Cl(-)), trifluoromethyl sulfonimide ([NTf2](-)) and tris(pentafluoroethyl)trifluorophosphate ([FAP](-)) for anions. For CHF2CH3, [N((n)C4H9)4][BF4] and [N((n)C4H9)4][B{3,5-C6H3(CF3)2}4] have been investigated for comparison with the previously measured solubility and conductivity in CH2F2. We have found that [N((n)C4H9)4][Al(OC(CF3)3)4], [N((n)C4H9)4][FAP] and [N(CH3)4][FAP] have much higher molar conductivity in scCH2F2 at similar conditions than [N((n)C4H9)4][BF4], a widely used commercial electrolyte. Additionally, scCHF2CH3 shows potential for use as the solvent for supercritical fluid electrodeposition, especially at high temperatures since high density of this fluid can be achieved at lower operating pressures than similar fluids that can be used to produce electrochemical baths with comparable conductivity.

  5. Distinct difference in ionic transport behavior in polymer electrolytes depending on the matrix polymers and incorporated salts.

    Science.gov (United States)

    Seki, Shiro; Susan, Md Abu Bin Hasan; Kaneko, Taketo; Tokuda, Hiroyuki; Noda, Akihiro; Watanabe, Masayoshi

    2005-03-10

    Two different electrolyte salts, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and a room temperature ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMITFSI), were incorporated into network polymers to obtain ion-conductive polymer electrolytes. Network polymers of poly(ethylene oxide-co-propylene oxide) (P(EO/PO)) and poly(methyl methacrylate) (PMMA) were chosen as matrixes for LiTFSI and EMITFSI, respectively. Both of the polymer electrolytes were single-phase materials and were completely amorphous. Ionic conductivity of the polymer electrolytes was measured over a wide temperature range, with the lowest temperatures close to or below the glass transition temperatures (Tg). The Arrhenius plots of the conductivity for both of the systems exhibited positively curved profiles and could be well fit to the Vogel-Tamman-Fulcher (VTF) equation. The conductivity of the PMMA/EMITFSI electrolytes was higher at most by 3 orders of magnitude than that of the LiTFSI/P(EO/ PO) electrolytes at ambient temperature. When the ideal glass transition temperature, T0 (one of the VTF fitting parameters), was compared with the Tg, a difference in the ionic conduction was apparent in these systems. In the P(EO/PO)/LiTFSI electrolytes, the T0 and Tg increased in parallel with salt concentration and the T0 was lower than the Tg by ca. 50 degrees C. On the contrary, the difference between the T0 and the Tg increased with increasing content of PMMA in the PMMA/EMITFSI electrolytes, with the observed difference in the concentration range studied reaching up to ca. 100 degrees C. The conductivity at the Tg, sigma(Tg), for the LiTFSI/P(EO/PO) electrolytes was on the order of 10(-14-)10(-13) S cm(-1) and increased with increasing salt concentration, whereas that for the PMMA/EMITFSI polymer electrolytes reached 10(-7) S cm(-1) when the concentration of PMMA was high. The ion transport mechanism was discussed in terms of the concepts of coupling

  6. Solution-processable electrochemiluminescent ion gels for flexible, low-voltage, emissive displays on plastic.

    Science.gov (United States)

    Moon, Hong Chul; Lodge, Timothy P; Frisbie, C Daniel

    2014-03-05

    Ion gels comprising ABA triblock copolymers and ionic liquids have received much attention as functional materials in numerous applications, especially as gate dielectrics in organic transistors. Here we have expanded the functionality of ion gels by demonstrating low-voltage, flexible electrochemiluminescent (ECL) devices using patterned ion gels containing redox-active luminophores. The ECL devices consisted only of a 30 μm thick emissive gel and two electrodes and were fabricated on indium tin oxide-coated substrates (e.g., polyester) simply by solution-casting the ECL gel and brush-painting a top Ag electrode. The triblock copolymer employed in the gel was polystyrene-block-poly(methyl methacrylate)-block-polystyrene, where the solvophobic polystyrene end blocks associate into micellar cross-links in the versatile ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMI][TFSI]). An ECL gel containing ~6.25 wt % Ru(bpy)3Cl2 (relative to [EMI][TFSI]) as the luminophore turned on at an AC peak-to-peak voltage as low as 2.6 V (i.e., -1.3 to +1.3 V) and showed a relatively rapid response (sub-ms). The wavelength of maximum emission was 610 nm (red-orange). With the use of an iridium(III) complex, Ir(diFppy)2(bpy)PF6 [diFppy = 2-(2',4'-difluorophenyl)pyridine; bpy = 2,2'-bipyridyl], the emitting color was tuned to a maximum wavelength of 540 nm (green). Moreover, when a blended luminophore system containing a 60:40 mixture of Ru(bpy)3(2+) and Ir(diFppy)2(bpy)(+) was used in the emissive layer, the luminance of red-orange-colored light was enhanced by a factor of 2, which is explained by the generation of the additional excited state Ru(bpy)3(2+)* by a coreactant pathway with Ir(diFppy)2(bpy)(+)* in addition to the usual annihilation pathway. This is the first time that enhanced ECL has been achieved in ion gels (or ionic liquids) using a coreactant. Overall, the results indicate that ECL ion gels are attractive multifunctional materials for

  7. Prominent roles of impurities in ionic liquid for catalytic conversion of carbohydrates

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Haibo; Brown, Heather M.; Holladay, Johnathan E.; Zhang, Z. Conrad

    2012-02-07

    In the last two decades, ionic liquids have emerged as new and versatile solvents, and many of them are also catalysts for a broad range of catalytic reactions. Certain ionic liquids have been found to possess the unique capability of dissolving cellulosic biomass. The potential of such ionic liquids as solvent to enable catalytic conversion of cellulosic polymers was first explored and demonstrated by Zhao et al. This field of research has since experienced a rapid growth. Most ionic liquids have negligible vapor pressure and excellent thermal stability over a wide temperature range. For example, ionic liquids composed of 1-ethyl-3-methylimidazolium (EMIM+) cation and Cl- anion was reported to be stable up to 285 C, while salts of the same cation with other anions such as BF4- and PF6- are thermally stable above 380 C under inert atmosphere. It is well known that presence of impurities in ionic liquids typically causes changes in physical properties, e.g. decreasing in melting point and viscosity. Addition of Lewis acidic metal chlorides, e.g. AlCl3 to 1-alkyl-3-methylimidazolium chloride, [AMIM]Cl, is an exothermic reaction and considerably reduces the melting point by forming [AMIM]AlCl4 or [AMIM]Al2Cl7 that are also ionic liquids but have much lower melting point than the parent [AMIM]Cl. While most early research on catalysis of ionic liquids involving metallohalide anions were typically conducted from stoichiometric ratio of such anions to organic cations, e.g. [AMIM]+, the use of pure ionic liquids only as a solvent to carry out catalysis by a catalytic amount of a metal halide as catalyst truly displayed the solvent property of such ionic liquids.4 In such reaction systems, catalytic amounts of metal halides were used to catalyze the conversion of glucose and cellulose.4,11,12 The metal chloride catalyst concentration was in the order of 10-3 M. The presence of another metal chloride in the ionic liquids, even in the order of 10-5 M concentration was found

  8. Ionic fluids in lubrication of aluminium-steel contacts. Surface and tribochemical interactions

    Science.gov (United States)

    Jimenez Ballesta, Ana Eva

    Room-temperature ionic liquids (ILs) are high performance fluids with a wide thermal stability range. They are being studied as new lubricants in a variety of sliding contacts. One of their more interesting tribological applications is that of steel-aluminium lubrication. In this work we study the influence of the lateral alkyl chain length and of the anion on the lubricating ability of six imidazolium ILs, a pyridinium and a phosphonium derivative. For first time, these ILs have been studied as neat lubricants and as 1wt.% base oil additives in variable conditions of velocity, load and temperature in pin-on-disk tests for AISI 52100 steel-ASTM 2011 aluminium contacts. In this work we present the first study of ILs as lubricants under extreme temperature conditions. The tribological performance of ILs has been compared with that of a mineral oil and of a synthetic ester. Under these conditions, ILs show lower friction and wear values than conventional oils at all temperatures. As 1wt.% additives, the conditions of optimum lubrication and the transitions between regimes and lubrication mechanisms have been determined. We have also studied the performance of ILs as 1wt.% additives of the synthetic oil. A relationship between additive polarity and wear index has been established. If the more soluble phosphonium IL additive is used, no friction or wear reduction takes place due to competition between solvation and adsorption processes. Electronic microscopy (SEM), energy dispersive (EDS) and X-ray photoelectron (XPS) spectroscopies have been used to study the wear mechanisms and tribochemical processes that take place in the contact. Finally, we have studied the performance of three aluminium alloys in corrosion and erosion-corrosion tests. In immersion tests with free-water ILs, the aluminium alloy 2011 shows a good resistance to corrosion, but dilution of 1-ethyl, 3-methylimidazolium tetrafluoroborate in water produces the hydrolysis of the anion and the corrosion of

  9. 离子液体中Lewis酸催化葡萄糖和果糖脱水制备5-羟甲基呋喃甲醛%Dehydration of Glucose and Fructose into 5-Hydroxymethylfurfural Catalyzed by Lewis Acid in Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    田玉奎; 邓晋; 潘涛; 郭庆祥; 傅尧

    2011-01-01

    在离子液体中采用不同的Lewis酸催化葡萄糖和果糖脱水制备5-羟甲基呋喃甲醛(5-HMF).结果表明,CrCln和SnCln均可高效催化葡萄糖转化为5-HMF.另外,Lewis酸的酸性越强,其催化果糖转化为5-HMF的产率越高.镧系金属氯化物在反应中表现出较好的催化活性和产物选择性.同时还研究了离子液体结构对催化反应的影响.结果表明,咪唑型离子液体在葡萄糖转化为5-HMF的反应中表现出明显的奇偶效应,即离子液体支链碳原予数为偶数时,5-HMF产率较高;而在果糖转化为5-HMF的反应中,离子液体的支链烷基长度越短,5-HMF产率越高.在离子液体[C2MIM]Br(溴化1-乙基-3-甲基咪唑)中,SnCl2催化葡萄糖脱水时5-HMF收率为65%,而ErCl3催化果糖得到的5-HMF收率可达92%.%A variety of Lewis acids have been examined for the transformation of glucose and fructose into 5-hydroxymethylfurfural (5-HMF) in ionic liquids (ILs). SnCln and CrCln are effective catalysts for the isomerization, and Lewis acids with strong acidity can facili tate the dehydration of fructose. The influence of ILs structure, including the length of alkyl side chain and halide anions, on the conversion was also studied. A distinct odd-even carbon-atom-number effect is observed in the conversion of glucose to 5-HMF and the imidazolium bromides with short alkyl side-chains can provide a higher yield of 5-HMF from fructose. In the presence of 1-ethyl-3-methylimidazolium bromide ([C2MIM]Br) and SnCl2, the yields of 5-HMF are 65% and 73% from glucose and fructose, respectively.

  10. Computational and Experimental Investigation of Li-doped Ionic Liquid Electrolytes: [pyr14][tfsi], [pyr13][fsi], and [EMIM][BF4

    Science.gov (United States)

    Haskins, Justin B.; Bennett, William R.; Wu, James J.; Hernandez, Dionne M.; Borodin, Oleg; Monk, Joshua D.; Bauschlicher, Charles W.; Lawson, John W.

    2014-01-01

    We employ molecular dynamics (MD) simulation and experiment to investigate the structure, thermodynamics, and transport of N-methyl-N-butylpyrrolidinium bis(trifluoromethylsufonyl)imide ([pyr14][TFSI]), N -methyl-N-propylpyrrolidinium bis(fluorosufonyl)imide ([pyr13][FSI]), and 1-ethyl-3-methylimidazolium boron tetrafluoride ([EMIM][BF4]), as a function of Li-salt mole fraction (0.05 xLi+ 0.33) and temperature (298 K T 393 K). Structurally, Li+ is shown to be solvated by three anion neigh- bors in [pyr14][TFSI] and four anion neighbors in both [pyr13][FSI] and [EMIM][BF4], and at all levels of xLi+ we find the presence of lithium aggregates. Pulsed field gradient spin-echo NMR measurements of diffusion and electrochemical impedance spectroscopy measurements of ionic conductivity are made for the neat ionic liquids as well as 0.5 molal solutions of Li-salt in the ionic liquids. Bulk ionic liquid properties (density, diffusion, viscosity, and ionic conductivity) are obtained with MD and show excellent agreement with experiment. While the diffusion exhibits a systematic decrease with increasing xLi+, the contribution of Li+ to ionic conductivity increases until reach- ing a saturation doping level of xLi+ 0.10. Comparatively, the Li+ conductivity of [pyr14][TFSI] is an order of magnitude lower than that of the other liquids, which range between 0.1-0.3 mScm. Our transport results also demonstrate the necessity of long MD simulation runs ( 200 ns) required to converge transport properties at room T. The differences in Li+ transport are reflected in the residence times of Li+ with the anions (Li), which are revealed to be much larger for [pyr14][TFSI] (up to 100 ns at the highest doping levels) than in either [EMIM][BF4] or [pyr13][FSI]. Finally, to comment on the relative kinetics of Li+ transport in each liquid, we find that while the net motion of Li+ with its solvation shell (vehicular) significantly contributes to net diffusion in all liquids, the importance of

  11. High-performance Supercapacitors Based on Electrochemical-induced Vertical-aligned Carbon Nanotubes and Polyaniline Nanocomposite Electrodes

    Science.gov (United States)

    Wu, Guan; Tan, Pengfeng; Wang, Dongxing; Li, Zhe; Peng, Lu; Hu, Ying; Wang, Caifeng; Zhu, Wei; Chen, Su; Chen, Wei

    2017-01-01

    Supercapacitors, which store electrical energy through reversible ion on the surface of conductive electrodes have gained enormous attention for variously portable energy storage devices. Since the capacitive performance is mainly determined by the structural and electrochemical properties of electrodes, the electrodes become more crucial to higher performance. However, due to the disordered microstructure and low electrochemical activity of electrode for ion tortuous migration and accumulation, the supercapacitors present relatively low capacitance and energy density. Here we report a high-performance supercapacitor based on polyaniline/vertical-aligned carbon nanotubes (PANI/VA-CNTs) nanocomposite electrodes where the vertical-aligned-structure is formed by the electrochemical-induction (0.75 V). The supercapacitor displays large specific capacitance of 403.3 F g−1, which is 6 times higher than disordered CNTs in HClO4 electrolyte. Additionally, the supercapacitor can also present high specific capacitance (314.6 F g−1), excellent cycling stability (90.2% retention after 3000 cycles at 4 A g−1) and high energy density (98.1 Wh kg−1) in EMIBF4 organic electrolyte. The key to high-performance lies in the vertical-aligned-structure providing direct path channel for ion faster diffusion and high electrochemical capacitance of polyaniline for ion more accommodation. PMID:28272474

  12. Electrochemical behavior of aluminum foil in 1-alkyl-3-methylimidazolium tetrafiuoroborate ionic liquids electrolytes

    Institute of Scientific and Technical Information of China (English)

    PENG Chengxin; YANG Li; WANG Baofeng; ZHANG Zhengxi; LI Nan

    2006-01-01

    Aluminum (Al) foil is widely used as a current collector in lithium ion batteries, EDLCs and other electrochemical devices, and its electrochemical behavior in electrolytes has great effect on the cycle performances and safety of the electrochemical devices. In this work, corrosion behavior of Al foil in 1-alkyl-3-methylimidazolium tetrafluoroborate ionic liquids and its electrolytes containing LiTFSI as salt were studied using cyclic voltammogram method. It was found that a passive film was firmly formed on the surface of Al foil after the anodic polarization in BMI-BF4 compared to those in EMI-BF4 and PMI-BF4.In addition, anodic polarization research showed that the passive film on Al surface in BMI-TFSI did not well exist. A good passive film formed on the surface of Al foil in BMI-BF4 was not broken down until the potential was up to 94.58 V. Moreover, EDX and XPS analysis showed that F and O exist on the Al surface after the anodic polarization in BMI-BF4, which indicated that a passive film like AIF3 and Al2O3 may be formed on its surface.

  13. Interconnected Hierarchical Porous Carbon from Lignin-Derived Byproducts of Bioethanol Production for Ultra-High Performance Supercapacitors.

    Science.gov (United States)

    Zhang, Liming; You, Tingting; Zhou, Tian; Zhou, Xia; Xu, Feng

    2016-06-08

    The advent of bioethanol production has generated abundant lignin-derived byproducts which contain proteins and polysaccharides. These byproducts are inapplicable for direct material applications. In this study, lignin-derived byproducts were used for the first time as carbon precursors to construct an interconnected hierarchical porous nitrogen-doped carbon (HPNC) via hydrothermal treatment and activation. The obtained HPNC exhibited favorable features for supercapacitor applications, such as hierarchical bowl-like pore structures, a large specific surface area of 2218 m(2) g(-1), a high electronic conductivity of 4.8 S cm(-1), and a nitrogen doping content of 3.4%. HPNC-based supercapacitors in a 6 M KOH aqueous electrolyte exhibited high-rate performance with a high specific capacitance of 312 F g(-1) at 1 A g(-1) and 81% retention at 80 A g(-1) as well as an excellent cyclic life of 98% initial capacitance after 20 000 cycles at 10 A g(-1). Moreover, HPNC-based supercapacitors in the ionic liquid electrolyte of EMI-BF4 displayed an enhanced energy density of 44.7 Wh kg(-1) (remaining 74% of max value) at an ultrahigh power density of 73.1 kW kg(-1). The proposed strategy may facilitate lignin utilization and lead to a green bioethanol production process.

  14. Ionic liquid pretreatment of poplar wood at room temperature: swelling and incorporation of nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, Marcel [Los Alamos National Laboratory; Macdonald, Brian A [Los Alamos National Laboratory; Wagner, Gregory L [Los Alamos National Laboratory; Joyce, Steven A [Los Alamos National Laboratory; Rector, Kirk D [Los Alamos National Laboratory

    2010-01-01

    Lignocellulosic biomass represents a potentially sustainable source of liquid fuels and commodity chemicals. It could satisfy the energy needs for transportation and electricity generation, while contributing substantially to carbon sequestration and limiting the accumulation of greenhouse gases in the atmosphere. Potential feedstocks are abundant and include crops, agricultural wastes, forest products, grasses, and algae. Among those feedstocks, wood is mainly constituted of three components: cellulose, hemicellulose, and lignin. The conversion process of lignocellulosic biomass typically consists of three steps: (1) pretreatment; (2) hydrolysis of cellulose and hemicellulose into fermentable sugars; and (3) fermentation of the sugars into liquid fuels (ethanol) and other commodity chemicals. The pretreatment step is necessary due to the complex structure of the plant cell wall and the chemical resistance of lignin. Most current pretreatments are energy-intensive and/or polluting. So it is imperative to develop new pretreatments that are economically viable and environmentally friendly. Recently, ionic liquids have attracted considerable interest, due to their ability to dissolve biopolymers, such as cellulose, lignin, native switchgrass, and others. Ionic liquids are also considered green solvents, since they have been successfully recycled at high yields for further use with limited efficiency loss. Also, a few microbial cellulases remain active at high ionic liquid concentration. However, all studies on the dissolution of wood in ionic liquids have been conducted so far at high temperatures, typically above 90 C. Development of alternative pretreatments at room temperature is desirable to eliminate the additional energy cost. In this study, thin sections of poplar wood were swollen at room temperature by a 3 h ionic liquid (1-ethyl-3-methylimidazolium acetate or EMIMAc) pretreatment. The pretreated sample was then exposed to an aqueous suspension of

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

    Directory of Open Access Journals (Sweden)

    Kilicarslan, Ayfer

    2016-03-01

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

  16. Structure-property relationships: Synthesis and characterization of Perovskite-related transition metal oxides

    Science.gov (United States)

    Whaley, Louis

    ; A B-site ordered double perovskite with an unusual a+b+c+ Glazer octahedral tilt system was synthesized, SrFe1/4Re3/4O 3; single crystals of two anhydrous 1-ethyl-3-methylimidazolium (EMI) salts, EMI octamolybdate, (C6H11N2) 4Mo8O26; and EMI decatungstate, (C6H 11N2)4W10O32; and single crystals of an incommensurate modulated phase, "Sr3CoRh2O 9-delta", with a structure comprising two interpenetrating modulated lattices. Properties of the phases are also reported.

  17. Volumetric Properties and Molecular Interactions of Binary Mixtures Imidazolium Acetates-ethanol at 293.15 K%293.15 K时咪唑醋酸盐-乙醇二元体系的体积性质及分子间相互作用

    Institute of Scientific and Technical Information of China (English)

    侯海云; 黄银蓉; 白博峰; 杨靖

    2014-01-01

    用比重瓶法测定了293.15 K时1-甲基咪唑醋酸盐([Mim]Ac)/1,3-二甲基咪唑醋酸盐([Mmim]Ac)/1-乙基-3-甲基咪唑醋酸盐([Emim]Ac)-乙醇(EtOH)二元体系在全组成范围内的密度.计算出[Mim]Ac/[ Mmim] Ac/[ Emim] Ac和EtOH的表观摩尔体积和体系的超额摩尔体积.用三参数多项式关联拟合了表观摩尔体积与摩尔分数的关系,外推出组分的极限偏摩尔体积和摩尔体积.[ Mim] Ac/[ Mmim] Ac/[ Emim] Ac和EtOH的摩尔体积的外推值与实验值分别在±0.07和±0.04 cm3/mol范围内相一致.计算出了[ Mim] Ac/[ Mmim] Ac/[ Emim] Ac和EtOH分别在无限稀溶液中的溶剂化系数.用Redlich-Kister 方程关联拟合了超额摩尔体积与摩尔分数的关系.分别根据极限偏摩尔体积、摩尔体积与极限偏摩尔体积的差值、溶剂化系数和超额摩尔体积对照讨论了分子间相互作用的强弱.结果显示,在[ Mim] Ac/[ Mmim] Ac/[ Emim] Ac的浓度无限稀溶液中,[ Mim] Ac/[ Mmim] Ac/[ Emim] Ac-EtOH 分子对间相互作用的强弱顺序为[ Mim] Ac-EtOH>[Mmim]Ac-EtOH>[Emim] Ac-EtOH;在 EtOH 的浓度无限稀溶液中,以及体系中[ Mim] Ac/[ Mmim] Ac/[ Emim] Ac的摩尔分数在0.15~0.95间时,[ Mim] Ac/[ Mmim] Ac/[ Emim] Ac-EtOH分子对间相互作用的强弱顺序都为[ Emim] Ac-EtOH>[ Mmim] Ac-EtOH>[ Mim] Ac-EtOH.%Over the full molar fraction range and at 293.15 K, the densities of binary systems 1-methylimi-dazolium acetate ( [ Mim ] Ac )/1 , 3-dimethylimidazolium acetate ( [ Mmim ] Ac )/1-ethyl-3-methylimidazolium acetate([Emim]Ac)(1)-ethanol(EtOH)(2) were measured by pycnometer method. The apparent molar volumes of [ Mim] Ac/[ Mmim] Ac/[ Emim] Ac and EtOH, and the excess molar volumes of the binary mix-tures were calculated. The relations of apparent molar volumes and molar fractions were fitted by three-parame-ter polynomials, from which, the limiting partial molar volumes and molar volumes were extrapolated. For [ Mim] Ac/[ Mmim] Ac/[ Emim