WorldWideScience

Sample records for carbon ionic liquid

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

    Science.gov (United States)

    Cui, Guokai; Wang, Jianji; Zhang, Suojiang

    2016-07-25

    Development of novel technologies for the efficient and reversible capture of CO2 is highly desired. In the last decade, CO2 capture using ionic liquids has attracted intensive attention from both academia and industry, and has been recognized as a very promising technology. Recently, a new approach has been developed for highly efficient capture of CO2 by site-containing ionic liquids through chemical interaction. This perspective review focuses on the recent advances in the chemical absorption of CO2 using site-containing ionic liquids, such as amino-based ionic liquids, azolate ionic liquids, phenolate ionic liquids, dual-functionalized ionic liquids, pyridine-containing ionic liquids and so on. Other site-containing liquid absorbents such as amine-based solutions, switchable solvents, and functionalized ionic liquid-amine blends are also investigated. Strategies have been discussed for how to activate the existent reactive sites and develop novel reactive sites by physical and chemical methods to enhance CO2 absorption capacity and reduce absorption enthalpy. The carbon capture mechanisms of these site-containing liquid absorbents are also presented. Particular attention has been paid to the latest progress in CO2 capture in multiple-site interactions by amino-free anion-functionalized ionic liquids. In the last section, future directions and prospects for carbon capture by site-containing ionic liquids are outlined. PMID:27243042

  2. Carbon films produced from ionic liquid carbon precursors

    Science.gov (United States)

    Dai, Sheng; Luo, Huimin; Lee, Je Seung

    2013-11-05

    The invention is directed to a method for producing a film of porous carbon, the method comprising carbonizing a film of an ionic liquid, wherein the ionic liquid has the general formula (X.sup.+a).sub.x(Y.sup.-b).sub.y, wherein the variables a and b are, independently, non-zero integers, and the subscript variables x and y are, independently, non-zero integers, such that ax=by, and at least one of X.sup.+ and Y.sup.- possesses at least one carbon-nitrogen unsaturated bond. The invention is also directed to a composition comprising a porous carbon film possessing a nitrogen content of at least 10 atom %.

  3. High performance ultracapacitors with carbon nanomaterials and ionic liquids

    Science.gov (United States)

    Lu, Wen; Henry, Kent Douglas

    2012-10-09

    The present invention is directed to the use of carbon nanotubes and/or electrolyte structures in various electrochemical devices, such as ultracapacitors having an ionic liquid electrolyte. The carbon nanotubes are preferably aligned carbon nanotubes. Compared to randomly entangled carbon nanotubes, aligned carbon nanotubes can have better defined pore structures and higher specific surface areas.

  4. Carbon dioxide in ionic liquid microemulsions.

    Science.gov (United States)

    Zhang, Jianling; Han, Buxing; Li, Jianshen; Zhao, Yueju; Yang, Guanying

    2011-10-10

    Tailor-made emulsion: a CO(2) -in-ionic-liquid microemulsion was produced for the first time. The CO(2)-swollen micelles are "tunable" because the micellar size can be easily adjusted by changing the pressure of CO(2). The microemulsion has potential applications in materials synthesis, chemical reactions, and extraction. PMID:21898733

  5. Carbon Dioxide Separation with Supported Ionic Liquid Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Luebke, D.R.; Ilconich, J.B.; Myers, C.R.; Pennline, H.W.

    2007-04-01

    Supported liquid membranes are a class of materials that allow the researcher to utilize the wealth of knowledge available on liquid properties as a direct guide in the development of a capture technology. These membranes also have the advantage of liquid phase diffusivities higher than those observed in polymeric membranes which grant proportionally greater permeabilities. The primary shortcoming of the supported liquid membranes demonstrated in past research has been the lack of stability caused by volatilization of the transport liquid. Ionic liquids, which possess high carbon dioxide solubility relative to light gases such as hydrogen, are an excellent candidate for this type of membrane since they have negligible vapor pressure and are not susceptible to evaporation. A study has been conducted evaluating the use of several ionic liquids, including 1-hexyl-3-methyl-imidazolium bis(trifuoromethylsulfonyl)imide, 1-butyl-3-methyl-imidazolium nitrate, and 1-ethyl-3-methyl-imidazolium sulfate in supported ionic liquid membranes for the capture of carbon dioxide from streams containing hydrogen. In a joint project, researchers at the University of Notre Dame lent expertise in ionic liquid synthesis and characterization, and researchers at the National Energy Technology Laboratory incorporated candidate ionic liquids into supports and evaluated the resulting materials for membrane performance. Initial results have been very promising with carbon dioxide permeabilities as high as 950 barrers and significant improvements in carbon dioxide/hydrogen selectivity over conventional polymers at 37C and at elevated temperatures. Results include a comparison of the performance of several ionic liquids and a number of supports as well as a discussion of innovative fabrication techniques currently under development.

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

    Directory of Open Access Journals (Sweden)

    Kamalakanta Behera

    2015-12-01

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

  7. Carbons, ionic liquids and quinones for electrochemical capacitors

    OpenAIRE

    Raul eDiaz; Doherty, Andrew P.

    2016-01-01

    Carbons are the main electrode materials used in electrochemical capacitors, which are electrochemical energy storage devices with high power densities and long cycling lifetimes. However, increasing their energy density will improve their potential for commercial implementation. In this regard, the use of high surface area carbons and high voltage electrolytes are well known strategies to increase the attainable energy density, and lately ionic liquids have been explored as promising alterna...

  8. Carbons, Ionic Liquids, and Quinones for Electrochemical Capacitors

    OpenAIRE

    Díaz-Delgado, Raül; Doherty, Andrew P.

    2016-01-01

    Carbons are the main electrode materials used in supercapacitors, which are electrochemical energy storage devices with high power densities and long cycling lifetimes. However, increasing their energy density capacity will improve their potential for commercial implementation. In this regard, the use of high surface area carbons and high voltage electrolytes are well known strategies to increase the attainable energy density, and lately ionic liquids have been explored as promising alternati...

  9. Carbons, ionic liquids and quinones for electrochemical capacitors

    Directory of Open Access Journals (Sweden)

    Raul eDiaz

    2016-04-01

    Full Text Available Carbons are the main electrode materials used in electrochemical capacitors, which are electrochemical energy storage devices with high power densities and long cycling lifetimes. However, increasing their energy density will improve their potential for commercial implementation. In this regard, the use of high surface area carbons and high voltage electrolytes are well known strategies to increase the attainable energy density, and lately ionic liquids have been explored as promising alternatives to current state of the art acetonitrile-based electrolytes. Also, in terms of safety and sustainability ionic liquids are attractive electrolyte materials for electrochemical capacitors. In addition, it has been shown that the matching of the carbon pore size with the electrolyte ion size further increases the attainable electric double layer (EDL capacitance and energy density.The use of pseudocapacitive reactions can significantly increase the attainable energy density, and quinonic-based materials offer a potentially sustainable and cost effective research avenue for both the electrode and the electrolyte. This perspective will provide an overview of the current state of the art research on electrochemical capacitors based on combinations of carbons, ionic liquids and quinonic compounds, highlighting performances and challenges and discussing possible future research avenues. In this regard, current interest is mainly focused on strategies which may ultimately lead to commercially competitive sustainable high performance electrochemical capacitors for different applications including those requiring mechanical flexibility and biocompatibility.

  10. Carbons, ionic liquids and quinones for electrochemical capacitors

    Science.gov (United States)

    Diaz, Raul; Doherty, Andrew

    2016-04-01

    Carbons are the main electrode materials used in electrochemical capacitors, which are electrochemical energy storage devices with high power densities and long cycling lifetimes. However, increasing their energy density will improve their potential for commercial implementation. In this regard, the use of high surface area carbons and high voltage electrolytes are well known strategies to increase the attainable energy density, and lately ionic liquids have been explored as promising alternatives to current state of the art acetonitrile-based electrolytes. Also, in terms of safety and sustainability ionic liquids are attractive electrolyte materials for electrochemical capacitors. In addition, it has been shown that the matching of the carbon pore size with the electrolyte ion size further increases the attainable electric double layer (EDL) capacitance and energy density. The use of pseudocapacitive reactions can significantly increase the attainable energy density, and quinonic-based materials offer a potentially sustainable and cost effective research avenue for both the electrode and the electrolyte. This perspective will provide an overview of the current state of the art research on electrochemical capacitors based on combinations of carbons, ionic liquids and quinonic compounds, highlighting performances and challenges and discussing possible future research avenues. In this regard, current interest is mainly focused on strategies which may ultimately lead to commercially competitive sustainable high performance electrochemical capacitors for different applications including those requiring mechanical flexibility and biocompatibility.

  11. Ionic Liquid Membranes for Carbon Dioxide-Methane Separation

    Czech Academy of Sciences Publication Activity Database

    Uchytil, Petr; Schauer, Jan; Pientka, Zbyněk; Petričkovič, Roman; Suen, S.-Y.

    2010, s. 1. ISBN N. [AMS6/IMSTEC10. Sydney (AU), 22.11.2010-25.11.2010] R&D Projects: GA ČR GA104/09/1165; GA ČR GCP106/10/J038 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40500505 Keywords : carbon dioxide * methane * ionic liquid membranes Subject RIV: CB - Analytical Chemistry, Separation

  12. Carbon dioxide in an ionic liquid: Structural and rotational dynamics

    Science.gov (United States)

    Giammanco, Chiara H.; Kramer, Patrick L.; Yamada, Steven A.; Nishida, Jun; Tamimi, Amr; Fayer, Michael D.

    2016-03-01

    Ionic liquids (ILs), which have widely tunable structural motifs and intermolecular interactions with solutes, have been proposed as possible carbon capture media. To inform the choice of an optimal ionic liquid system, it can be useful to understand the details of dynamics and interactions on fundamental time scales (femtoseconds to picoseconds) of dissolved gases, particularly carbon dioxide (CO2), within the complex solvation structures present in these uniquely organized materials. The rotational and local structural fluctuation dynamics of CO2 in the room temperature ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EmimNTf2) were investigated by using ultrafast infrared spectroscopy to interrogate the CO2 asymmetric stretch. Polarization-selective pump probe measurements yielded the orientational correlation function of the CO2 vibrational transition dipole. It was found that reorientation of the carbon dioxide occurs on 3 time scales: 0.91 ± 0.03, 8.3 ± 0.1, 54 ± 1 ps. The initial two are attributed to restricted wobbling motions originating from a gating of CO2 motions by the IL cations and anions. The final (slowest) decay corresponds to complete orientational randomization. Two-dimensional infrared vibrational echo (2D IR) spectroscopy provided information on structural rearrangements, which cause spectral diffusion, through the time dependence of the 2D line shape. Analysis of the time-dependent 2D IR spectra yields the frequency-frequency correlation function (FFCF). Polarization-selective 2D IR experiments conducted on the CO2 asymmetric stretch in the parallel- and perpendicular-pumped geometries yield significantly different FFCFs due to a phenomenon known as reorientation-induced spectral diffusion (RISD), revealing strong vector interactions with the liquid structures that evolve slowly on the (independently measured) rotation time scales. To separate the RISD contribution to the FFCF from the structural spectral

  13. Carbon-Carbon Cross Coupling Reactions in Ionic Liquids Catalysed by Palladium Metal Nanoparticles

    OpenAIRE

    Martin H. G. Prechtl; Scholten, Jackson D.; Jairton Dupont

    2010-01-01

    A brief summary of selected pioneering and mechanistic contributions in the field of carbon-carbon cross-coupling reactions with palladium nanoparticles (Pd-NPs) in ionic liquids (ILs) is presented. Five exemplary model systems using the Pd-NPs/ILs approach are presented: Heck, Suzuki, Stille, Sonogashira and Ullmann reactions which all have in common the use of ionic liquids as reaction media and the use of palladium nanoparticles as reservoir for the catalytically active palladium species.

  14. Ultrafast diffusion of Ionic Liquids Confined in Carbon Nanotubes.

    Science.gov (United States)

    Ghoufi, Aziz; Szymczyk, Anthony; Malfreyt, Patrice

    2016-01-01

    Over the past decade many works have focused on various aspects of the dynamics of liquids confined at the nanoscale such as e.g. water flow enhancement through carbon nanotubes (CNTs). Transport of room temperature ionic liquids (RTILs) through various nanochannels has also been explored and some conflicting findings about their translational dynamics have been reported. In this work, we focus on translational dynamics of RTILs confined in various CNTs. By means of molecular dynamics simulations we highlight a substantially enhanced diffusion of confined RTILs with an increase up to two orders of magnitude with respect to bulk-phase properties. This ultrafast diffusion of RTILs inside CNTs is shown to result from the combination of various factors such as low friction, molecular stacking, size, helicity, curvature and cooperative dynamics effects. PMID:27334208

  15. Electrochemical detection of rutin with a carbon ionic liquid electrode modified by Nafion, graphene oxide and ionic liquid composite

    International Nuclear Information System (INIS)

    We report on a carbon ionic liquid electrode modified with a composite made from Nafion, graphene oxide and ionic liquid, and its application to the sensitive determination of rutin. The modified electrode was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. It shows excellent cyclic voltammetric and differential pulse voltammetric performance due to the presence of nanoscale graphene oxide and the ionic liquid, and their interaction. A pair of well-defined redox peaks of rutin appears at pH 3.0, and the reduction peak current is linearly related to its concentration in the range from 0.08 μM to 0.1 mM with a detection limit of 0.016 μM (at 3σ). The modified electrode displays excellent selectivity and good stability, and was successfully applied to the determination of rutin in tablets with good recovery. (author)

  16. Effect of phosphonium-based ionic liquids on the corrosion of carbon steel under gamma radiation

    International Nuclear Information System (INIS)

    The interactions of two ionic liquids with carbon steel surfaces were studied in absence and presence of γ-radiation. Both studied ionic liquids were found to corrode the carbon steel. One of the ionic liquids (labelled [P66614]+ [Br]-) was found to produce corrosion products both with and without radiation present. The second ionic liquid (labelled [P66614]+ [NTf2]-) did not corrode the steel in absence of γ-radiation, but did corrode it in the presence of γ-radiation. (author)

  17. High performance batteries with carbon nanomaterials and ionic liquids

    Science.gov (United States)

    Lu, Wen

    2012-08-07

    The present invention is directed to lithium-ion batteries in general and more particularly to lithium-ion batteries based on aligned graphene ribbon anodes, V.sub.2O.sub.5 graphene ribbon composite cathodes, and ionic liquid electrolytes. The lithium-ion batteries have excellent performance metrics of cell voltages, energy densities, and power densities.

  18. Combined physical and chemical absorption of carbon dioxide in a mixture of ionic liquids

    International Nuclear Information System (INIS)

    Highlights: • Carbon dioxide can be absorbed in mixtures of two ionic liquids: [C2mim][EtSO4] and [C2mim][OAc]. • A combination of physical and chemical absorption mechanisms is observed. • The CO2 absorption capacity of the mixture of ionic liquids decreases with increasing temperature. • [C2mim][EtSO4] in the mixture prevents solidification of the product resulting from reaction of [C2mim][OAc] and CO2. • Density and viscosity studies of the mixture of ionic liquids also lead to synergies, in particular at low temperatures. - Abstract: Ionic liquids have attracted great interest recently as the basis of a potential alternative technology for the capture of carbon dioxide. Beyond the inherent tunability of properties of individual ionic liquids, a further strategy in optimising the ionic liquid sorbent for this application is the use of mixtures of ‘pure’ ionic liquids. Some ionic liquids absorb CO2 physically, whereas others do so chemically. Both mechanisms of absorption present advantages and disadvantages for a CO2 capture process operating in a continuous regime. In this work, a mixture of 1-ethyl-3-methylimidazolium acetate (an ionic liquid that reacts chemically with CO2) and 1-ethyl-3-methylimidazolium ethylsulfate (an ionic liquid that absorbs CO2 only through a physical mechanism) was investigated for the absorption of CO2 as a function of temperature and at pressures up to 17 bar. The absorption/desorption studies were complemented by the characterisation of thermal and physical properties of the mixture of ionic liquids, which provide extra information on the interactions at a molecular level, and are also critical for the assessment of its suitability for a proposed process and for the subsequent process design

  19. Immobilization of Lipase on Single Walled Carbon Nanotubes in Ionic Liquid

    International Nuclear Information System (INIS)

    A lipase from Pseudomonas cepacia was immobilized onto single walled carbon nanotubes (SWNTs) in two different ways in each of two solvent systems (buffer and ionic liquid). The most efficient immobilization was achieved in ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate, BMIM-BF4). In this procedure, carbon nanotubes were first functionalized noncovalently with 1-pyrenebutyric acid N-hydroxysuccinimide ester and then subject to the coupling reaction with the lipase in ionic liquid. The resulting immobilized enzyme displayed the highest activity in the transesterification of 1-phenylethyl alcohol in the presence of vinyl acetate in toluene

  20. Comparative investigation on electrochemical behavior of hydroquinone at carbon ionic liquid electrode, ionic liquid modified carbon paste electrode and carbon paste electrode

    International Nuclear Information System (INIS)

    Ionic liquid, 1-heptyl-3-methylimidazolium hexafluorophosphate (HMIMPF6), has been used to fabricate two new electrodes, carbon ionic liquid electrode (CILE) and ionic liquid modified carbon paste electrode (IL/CPE), using graphite powder mixed with HMIMPF6 or the mixture of HMIMPF6/paraffin liquid as the binder, respectively. The electrochemical behaviors of hydroquinone at the CILE, the IL/CPE and the CPE were investigated in phosphate buffer solution. At all these electrodes, hydroquinone showed a pair of redox peaks. The order of the current response and the standard rate constant of hydroquinone at these electrodes were as follows: CILE > IL/CPE > CPE, while the peak-to-peak potential separation was in an opposite sequence: CILE < IL/CPE < CPE. The results show the superiority of CILE to IL/CPE and CPE, and IL/CPE to CPE in terms of promoting electron transfer, improving reversibility and enhancing sensitivity. The CILE was chosen as working electrode to determine hydroquinone by differential pulse voltammetry, which can be used for sensitive, simple and rapid determination of hydroquinone in medicated skin cosmetic cream

  1. 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.

  2. Sustainable Ways of Combining Reactions and Separations Using Ionic Liquids and Carbon Dioxide

    OpenAIRE

    Kazemi, S.

    2013-01-01

    Traditional chemical processes show shortcomings caused by using volatile organic compounds as solvents during reactions and separations. Therefore, it is necessary to address this issue by moving toward more environmentally friendly processes. This is possible by using less toxic and hazardous solvents, such as ionic liquids and supercritical carbon dioxide (scCO2). Ionic liquids have attracted a lot of attention as potential “green” solvents to replace conventional organic solvents due to t...

  3. Relation Between the Composition and Properties of Carbon Ionic Liquid Electrodes (CILEs)

    Czech Academy of Sciences Publication Activity Database

    Mikysek, T.; Stočes, M.; Jovanovski, V.; Sopha, H.; Švancara, I.; Ludvík, Jiří

    Pardubice : University Press Centre, 2011 - (Kalcher, K.; Metelka, R.; Švancara, I.; Vytřas, K.), s. 157-166 ISBN 978-80-7395-434-5 R&D Projects: GA MŠk LC510 Institutional research plan: CEZ:AV0Z40400503 Keywords : carbon ionic liquid electrode * carbon paste electrode * characterization Subject RIV: CG - Electrochemistry

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

    Science.gov (United States)

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

    2015-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-27

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

  6. Single-walled carbon nanotubes modified carbon ionic liquid electrode for sensitive electrochemical detection of rutin

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Zhihong [Institute of Nano-Science and Technology Center, Huazhong Normal University, Wuhan 430079 (China); Sun Xiaoying; Zhuang Xiaoming [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Zeng Yan [Institute of Nano-Science and Technology Center, Huazhong Normal University, Wuhan 430079 (China); Sun Wei, E-mail: sunwei@qust.edu.c [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Huang Xintang [Institute of Nano-Science and Technology Center, Huazhong Normal University, Wuhan 430079 (China)

    2010-11-01

    The single-walled carbon nanotubes (SWCNTs) modified carbon ionic liquid electrode (CILE) was designed and further used for the voltammetric detection of rutin in this paper. CILE was prepared by mixing graphite powder with ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate and liquid paraffin together. Based on the interaction of SWCNTs with IL present on the electrode surface, a stable SWCNTs film was formed on the CILE to get a modified electrode denoted as SWCNTs/CILE. The characteristics of SWCNTs/CILE were recorded by different methods including cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. The electrochemical behaviors of rutin on the SWCNTs/CILE were investigated by cyclic voltammetry and differential pulse voltammetry. Due to the specific interface provided by the SWCNTs-IL film, the electrochemical response of rutin was greatly enhanced with a pair of well-defined redox peaks appeared in pH 2.5 phosphate buffer solution. The oxidation peak currents showed good linear relationship with the rutin concentration in the range from 1.0 x 10{sup -7} to 8.0 x 10{sup -4} mol/L with the detection limit as 7.0 x 10{sup -8} mol/L (3{sigma}). The SWCNTs/CILE showed the advantages such as excellent selectivity, improved performance, good stability and it was further applied to the rutin tablets sample detection with satisfactory results.

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

    Science.gov (United States)

    García, Gregorio; Atilhan, Mert; Aparicio, Santiago

    2015-09-17

    The N-ethyl-N-(furan-2-ylmethyl)ethanaminium dihydrogen phosphate ionic liquid was studied as a model of ionic liquids which can be produced from totally renewable sources. A computational study using both molecular dynamics and density functional theory methods was carried out. The properties, structuring, and intermolecular interactions (hydrogen bonding) of this fluid in the pure state were studied as a function of pressure and temperature. Likewise, the adsorption on graphene and the confinement between graphene sheets was also studied. The solvation of single walled carbon nanotubes in the selected ionic liquid was analyzed together with the behavior of ions confined inside these nanotubes. The reported results show remarkable properties for this fluid, which show that many of the most relevant properties of ionic liquids and their ability to interact with carbon nanosystems may be maintained and even improved using new families of renewable compounds instead of classic types of ionic liquids with worse environmental, toxicological, and economical profiles. PMID:26305599

  8. Direct electrochemistry and electrocatalysis of hemoglobin with carbon nanotube-ionic liquid-chitosan composite materials modified carbon ionic liquid electrode

    International Nuclear Information System (INIS)

    A novel composite biomaterial was prepared by combining chitosan, multi-walled carbon nanotubes (MWCNTs), hemoglobin (Hb) and ionic liquid (IL) 1-butyl-3-methyl-imidazolium bromide together, which was further modified on the surface of a carbon ionic liquid electrode (CILE) with another ionic liquid 1-ethyl-3-methylimidazolium ethylsulphate as the binder. Ultraviolet-visible and Fourier transform infrared spectroscopic results indicated that Hb molecules in the composite film retained the native structure. Cyclic voltammetric results showed that a pair of well-defined redox peaks appeared in 0.1 mol/L phosphate buffer solution, indicating that the direct electron transfer of Hb in the composite film with the underlying electrode was realized. The results were attributed to the synergistic effect of MWCNTs and IL in the composite film, which promoted the electron transfer rate of Hb. The composite material modified electrode showed excellent electrocatalytic ability towards the reduction of different substrates such as trichloroacetic acid and NaNO2 with good stability and reproducibility.

  9. Electrochemical determination of hydroquinone using hydrophobic ionic liquid-type carbon paste electrodes

    OpenAIRE

    Liu Hongtao; Tang Yougen; She Yiyi; He Ping

    2010-01-01

    Abstract Three types of carbon paste electrodes (CPEs) with different liquid binders were fabricated, and their electrochemical behavior was characterized via a potassium hexacyanoferrate(II) probe. 1-Octyl-3-methylimidazolium hexafluorophosphate ionic liquid (IL) as a hydrophobic conductive pasting binder showed better electrochemical performance compared with the commonly employed binder. The IL-contained CPEs demonstrated excellent electroactivity for oxidation of hydroquinone. A diffusion...

  10. Interfacial properties of a carbyne-rich nanostructured carbon thin film in ionic liquid

    Science.gov (United States)

    Giacomo Bettini, Luca; Della Foglia, Flavio; Piseri, Paolo; Milani, Paolo

    2016-03-01

    Nanostructured carbon sp2 (ns-C) thin films with up to 30% of sp-coordinated atoms (carbynes) were produced in a high vacuum by the low kinetic energy deposition of carbon clusters produced in the gas phase and accelerated by a supersonic expansion. Immediately after deposition the ns-C films were immersed in situ in an ionic liquid electrolyte. The interfacial properties of ns-C films in the ionic liquid electrolyte were characterized by electrochemical impedance spectroscopy and cyclic voltammetry (CV). The so-prepared carbyne-rich electrodes showed superior electric double layer (EDL) capacitance and electric conductivity compared to ns-C electrodes containing only sp2 carbon, showing the substantial influence of carbynes on the electrochemical properties of nanostructured carbon electrodes.

  11. Interfacial properties of a carbyne-rich nanostructured carbon thin film in ionic liquid.

    Science.gov (United States)

    Bettini, Luca Giacomo; Della Foglia, Flavio; Piseri, Paolo; Milani, Paolo

    2016-03-18

    Nanostructured carbon sp(2) (ns-C) thin films with up to 30% of sp-coordinated atoms (carbynes) were produced in a high vacuum by the low kinetic energy deposition of carbon clusters produced in the gas phase and accelerated by a supersonic expansion. Immediately after deposition the ns-C films were immersed in situ in an ionic liquid electrolyte. The interfacial properties of ns-C films in the ionic liquid electrolyte were characterized by electrochemical impedance spectroscopy and cyclic voltammetry (CV). The so-prepared carbyne-rich electrodes showed superior electric double layer (EDL) capacitance and electric conductivity compared to ns-C electrodes containing only sp(2) carbon, showing the substantial influence of carbynes on the electrochemical properties of nanostructured carbon electrodes. PMID:26878188

  12. Ionic Liquid Directed Mesoporous Carbon Nanoflakes as an Effiencient Electrode material

    Science.gov (United States)

    Kong, Lirong; Chen, Wei

    2015-01-01

    Supercapacitors are considered to be the most promising approach to meet the pressing requirements for energy storage devices. The electrode materials for supercapacitors have close relationship with their electrochemical properties and thus become the key point to improve their energy storage efficiency. Herein, by using poly (vinylidene fluoride-co-hexafluoropropylene) and ionic liquid as the dual templates, polyacrylonitrile as the carbon precursor, a flake-like carbon material was prepared by a direct carbonization method. In this method, poly (vinylidene fluoride-co-hexafluoropropylene) worked as the separator for the formation of isolated carbon flakes while aggregated ionic liquid worked as the pore template. The obtained carbon flakes exhibited a specific capacitance of 170 F/g at 0.1 A/g, a high energy density of 12.2 Wh/kg and a high power density of 5 kW/kg at the current of 10 A/g. It also maintained a high capacitance retention capability with almost no declination after 500 charge-discharge cycles. The ionic liquid directed method developed here also provided a new idea for the preparation of hierarchically porous carbon nanomaterials. PMID:26656464

  13. Thermotropic Ionic Liquid Crystals

    OpenAIRE

    Sabine Laschat; Axenov, Kirill V

    2011-01-01

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

  14. Acidic Ionic Liquids.

    Science.gov (United States)

    Amarasekara, Ananda S

    2016-05-25

    Ionic liquid with acidic properties is an important branch in the wide ionic liquid field and the aim of this article is to cover all aspects of these acidic ionic liquids, especially focusing on the developments in the last four years. The structural diversity and synthesis of acidic ionic liquids are discussed in the introduction sections of this review. In addition, an unambiguous classification system for various types of acidic ionic liquids is presented in the introduction. The physical properties including acidity, thermo-physical properties, ionic conductivity, spectroscopy, and computational studies on acidic ionic liquids are covered in the next sections. The final section provides a comprehensive review on applications of acidic ionic liquids in a wide array of fields including catalysis, CO2 fixation, ionogel, electrolyte, fuel-cell, membrane, biomass processing, biodiesel synthesis, desulfurization of gasoline/diesel, metal processing, and metal electrodeposition. PMID:27175515

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

    Science.gov (United States)

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

    2013-07-10

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

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

    Science.gov (United States)

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

    2015-04-01

    During the past decade, increasing attention has been paid to photoluminescent nanocarbon materials, namely, carbon quantum dots (CQDs). It is gradually accepted that surface engineering plays a key role in regulating the properties and hence the applications of the CQDs. In this paper, we prepared highly charged CQDs through a one-pot pyrolysis with citric acid as carbon source and a room-temperature imidazolium-based ionic liquid as capping agent. The as-prepared CQDs exhibit high quantum yields up to 25.1% and are stable under various environments. In addition, the amphiphilicity of the CQDs can be facilely tuned by anion exchange, which leads to a spontaneous phase transfer between water and oil phase. The promising applications of the CQDs as ion sensors and fluorescent inks have been demonstrated. In both cases, these ionic-liquid-modified CQDs were found to possess novel characteristics and/or superior functions compared to existing ones. PMID:25774972

  17. Composition and structural effects on the adsorption of ionic liquids onto activated carbon

    OpenAIRE

    Lemus, Jesús; Freire, Mara G.; Palomar, Jose; Neves, Catarina M. S. S.; Marques, Carlos F. C.; Coutinho, João A. P.

    2013-01-01

    The applications and variety of ionic liquids (ILs) have increased during the last few years, and their use at a large scale will require their removal/recovery from wastewater streams. Adsorption on activated carbons (ACs) has been recently proposed for this aim and this work presents a systematic analysis of the influence of the IL chemical structures (cation side chain, head group, anion type and the presence of functional groups) on their adsorption onto commercial AC from water solution....

  18. A Highly Viscous Imidazolium Ionic Liquid inside Carbon Nanotubes

    DEFF Research Database (Denmark)

    Ohba, T.; Chaban, Vitaly V.

    2014-01-01

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

  19. New Characterisation Approaches for Carbon Ionic Liquid Electrodes (CILES)

    Czech Academy of Sciences Publication Activity Database

    Mikysek, T.; Stočes, M.; Švancara, I.; Vytřas, K.; Ludvík, Jiří

    Ústí nad Labem : BEST servis, 2012 - (Navrátil, T.; Fojta, M.), s. 77-81 ISBN 978-80-905221-0-7. [Moderní elektrochemické metody /32./. Jetřichovice (CZ), 21.05.2012-25.05.2012] Institutional support: RVO:61388955 Keywords : carbon * paste * electrode Subject RIV: CG - Electrochemistry

  20. Electrochemical determination of hydroquinone using hydrophobic ionic liquid-type carbon paste electrodes

    Directory of Open Access Journals (Sweden)

    Liu Hongtao

    2010-10-01

    Full Text Available Abstract Three types of carbon paste electrodes (CPEs with different liquid binders were fabricated, and their electrochemical behavior was characterized via a potassium hexacyanoferrate(II probe. 1-Octyl-3-methylimidazolium hexafluorophosphate ionic liquid (IL as a hydrophobic conductive pasting binder showed better electrochemical performance compared with the commonly employed binder. The IL-contained CPEs demonstrated excellent electroactivity for oxidation of hydroquinone. A diffusion control mechanism was confirmed and the diffusion coefficient (D of 5.05 × 10-4 cm2 s-1 was obtained. The hydrophobic IL-CPE is promising for the determination of hydroquinone in terms of high sensitivity, easy operation, and good durability.

  1. Nacre-like calcium carbonate controlled by ionic liquid/graphene oxide composite template

    International Nuclear Information System (INIS)

    Nacre-like calcium carbonate nanostructures have been mediated by an ionic liquid (IL)-graphene oxide (GO) composite template. The resultant crystals were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and X-ray powder diffractometry (XRD). The results showed that either 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) or graphene oxide can act as a soft template for calcium carbonate formation with unusual morphologies. Based on the time-dependent morphology changes of calcium carbonate particles, it is concluded that nacre-like calcium carbonate nanostructures can be formed gradually utilizing [BMIM]BF4/GO composite template. During the process of calcium carbonate formation, [BMIM]BF4 acted not only as solvents but also as morphology templates for the fabrication of calcium carbonate materials with nacre-like morphology. Based on the observations, the possible mechanisms were also discussed. - Highlights: • Nacre-like CaCO3/GO were prepared by gas diffusion. • Ionic liquid/GO served as composite templates. • The interaction of Ca2+ ions and GO played a very important role in the formation of nacre-like CaCO3

  2. Molecular interactions between carbon nanotubes and ammonium ionic liquids and their catalysis properties

    International Nuclear Information System (INIS)

    Highlights: • We report interactions between multi-walled carbon nanotubes and ionic liquids. • Triethylammonium hydrogen phosphate ionic liquids are studied. • Raman spectroscopy is used to study interactions. • Morphological studies were carried out using scanning electron microscopy. • Bucky gel was used as catalyst for Michael reactions. - Abstract: A new catalytic method has been developed for the synthesis of aza/thia-Michael addition reactions of amines/thiols, which provide higher product yields. This catalyst is a combination of multi-walled carbon nanotubes (MWCNT) with triethylammonium hydrogen phosphate (TEAP) ionic liquid (IL), commonly referred to as bucky gel. In order to gain insight into the interactions involved between IL and MWCNT, we utilised Raman spectroscopy for our analysis. The interactions between MWCNT with TEAP were clearly evidenced by the increasing intensity ratios and spectral shift in the wavelength for the Raman D and G bands of MWCNT. The morphological studies of the resulting composite materials of TEAP and MWCNT (bucky gel) were carried out using scanning electron microscopy (SEM). The key advantage of using bucky gel as a catalyst is that higher product yield is obtained in reduced reaction time for Michael reactions

  3. Single-walled carbon nanotubes modified by ionic liquid as antiwear additives of thermoplastics

    OpenAIRE

    Carrión, F.J.; Espejo, C.; Sanes, J.; Bermúdez, M.D.

    2010-01-01

    Abstract Pristine single-walled carbon nanotubes (CNTs) were dispersed in the room-temperature ionic liquid (IL) 1-octyl, 3-methylimidazolium tetrafluoroborate ([OMIM]BF4) by grinding and ultrasounds. Excess IL was removed to obtain single-walled carbon nanotubes modified by [OMIM]BF4 (mCNTs). mCNTs were added in a 1wt.% to polystyrene (PS), polymethylmethacrylate (PMMA) and polycarbonate (PC) to obtain PS+mCNT, PMMA+mCNT and PC+mCNT. The dry tribological performance of the new nan...

  4. Nanoscale Carbon Greatly Enhances Mobility of a Highly Viscous Ionic Liquid

    DEFF Research Database (Denmark)

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

    2014-01-01

    liquids (ILs) and apolar carbon nanotubes (CNTs) are disparate objects; nevertheless, their interaction leads to spontaneous CNT filling with ILs. Moreover, ionic diffusion of highly viscous ILs can increase 5-fold inside CNTs, approaching that of molecular liquids, even though the confined IL phase still......The ability to encapsulate molecules is one of the outstanding features of nanotubes. The encapsulation alters physical and chemical properties of both nanotubes and guest species. The latter normally form a separate phase, exhibiting drastically different behavior compared to the bulk. Ionic...... contains exclusively ions. We exemplify these unusual effects by computer simulation on a highly hydrophilic, electrostatically structured, and immobile 1-ethyl-3-methylimidazolium chloride, [C2C1IM][CI]. Self-diffusion constants and energetic properties provide microscopic interpretation of the observed...

  5. Aqueous solutions of acidic ionic liquids for enhanced stability of polyoxometalate-carbon supercapacitor electrodes

    Science.gov (United States)

    Hu, Chenchen; Zhao, Enbo; Nitta, Naoki; Magasinski, Alexandre; Berdichevsky, Gene; Yushin, Gleb

    2016-09-01

    Nanocomposites based on polyoxometalates (POMs) nanoconfined in microporous carbons have been synthesized and used as electrodes for supercapacitors. The addition of the pseudocapacitance from highly reversible redox reaction of POMs to the electric double-layer capacitance of carbon lead to an increase in specific capacitance of ∼90% at 1 mV s-1. However, high solubility of POM in traditional aqueous electrolytes leads to rapid capacity fading. Here we demonstrate that the use of aqueous solutions of protic ionic liquids (P-IL) as electrolyte instead of aqueous sulfuric acid solutions offers an opportunity to significantly improve POM cycling stability. Virtually no degradation in capacitance was observed in POM-based positive electrode after 10,000 cycles in an asymmetric capacitor with P-IL aqueous electrolyte. As such, POM-based carbon composites may now present a viable solution for enhancing energy density of electrical double layer capacitors (EDLC) based on pure carbon electrodes.

  6. Determination of 4-aminophenylarsonic acid using a glassy carbon electrode modified with an ionic liquid and carbon nanohorns

    International Nuclear Information System (INIS)

    We have developed a sensor for 4-aminophenylarsonic acid (4-APhAA) by coating a glassy carbon electrode (GCE) with a composite prepared from an ionic liquid and dahlia-like carbon nanohorns (CNHs). The good electric conductivity, large surface area and high pore volume of the CNHs, and the synergistic action of the ionic liquid (which is a good dispersant with excellent ion conductivity) result in efficient electrocatalysis towards oxidation of 4-APhAA. The effect was investigated by various electrochemical methods, and the electron transfer coefficient, diffusion coefficient, standard heterogeneous rate constant and thermodynamic activation energy were determined. The response range of 4-APhAA was evaluated using an i-t plot. If operated at a working voltage of 900 mV (vs Ag/AgCl), the sensor responds to 4-APhAA over the 0.5 μM to 3.5 M concentration range. (author)

  7. Preparation of Multi-Walled Carbon Nanotube/Amino-Terminated Ionic Liquid Arrays and Their Electrocatalysis towards Oxygen Reduction

    OpenAIRE

    Li Niu; Ari Ivaska; Carita Kvarnström; Rose-Marie Latonen; Zhijuan Wang

    2010-01-01

    Arrays of aligned multi-walled carbon nanotube-ionic liquid (MIL) were assembled on silicon wafers (Si-MIL). Formation of Si-MIL was confirmed by ATR-FTIR, AFM and Raman techniques. The electrochemical measurements indicated that Si-MIL showed good electrocatalysis towards oxygen reduction compared with MIL drop-cast on a glassy carbon electrode.

  8. Electrochemical investigations of ionic liquids with vinylene carbonate for applications in rechargeable lithium ion batteries

    International Nuclear Information System (INIS)

    Ionic liquids based on methylpropylpyrrolidinium (MPPY) and methylpropylpiperidinium (MPPI) cations and bis(trifluoromethanesulfionyl)imide (TFSI) anion have been synthesized and characterized by thermal analysis, cyclic voltammetry, impedance spectroscopy as well as gavanostatic charge/discharge tests. 10 wt% of vinylene carbonate (VC) was added to the electrolytes of 0.5 M LiTFSI/MPPY.TFSI and 0.5 M LiTFSI/MPPI.TFSI, which were evaluated in Li || natural graphite (NG) half cells at 25 oC and 50 oC under different current densities. At 25 oC, due to their intrinsic high viscosities, the charge/discharge capacities under the current density of 80 A cm-2 were much lower than those under the current density of 40 A cm-2. At 50 oC, with reduced viscosities, the charge/discharge capacities under both current densities were almost indistinguishable, which were also close to the typical values obtained using conventional carbonate electrolytes. In addition, the discharge capacities of the half cells were very stable with cycling, due to the effective formation of solid electrolyte interphase (SEI) on the graphite electrode. On the contrary, the charge/discharge capacities of the Li || LiCoO2 cells using both ionic liquid electrolytes under the current density of 40 A cm-2 decreased continually with cycling, which were primarily due to the low oxidative stability of VC on the surface of LiCoO2.

  9. Electrochemical investigations of ionic liquids with vinylene carbonate for applications in rechargeable lithium ion batteries

    International Nuclear Information System (INIS)

    Ionic liquids based on methylpropylpyrrolidinium (MPPY) and methylpropylpiperidinium (MPPI) cations and bis(trifluoromethanesulfonyl)imide (TFSI) anion have been synthesized and characterized by thermal analysis, cyclic voltammetry, impedance spectroscopy as well as galvanostatic charge/discharge tests. 10 wt% of vinylene carbonate (VC) was added to the electrolytes of 0.5 M LiTFSI/MPPY.TFSI and 0.5 M LiTFSI/MPPI.TFSI, which were evaluated in Li || natural graphite (NG) half cells at 25 deg. C and 50 deg. C under different current densities. At 25 deg. C, due to their intrinsic high viscosities, the charge/discharge capacities under the current density of 80 μA cm-2 were much lower than those under the current density of 40 μA cm-2. At 50 deg. C, with reduced viscosities, the charge/discharge capacities under both current densities were almost indistinguishable, which were also close to the typical values obtained using conventional carbonate electrolytes. In addition, the discharge capacities of the half cells were very stable with cycling, due to the effective formation of solid electrolyte interphase (SEI) on the graphite electrode. On the contrary, the charge/discharge capacities of the Li || LiCoO2 cells using both ionic liquid electrolytes under the current density of 40 μA cm-2 decreased continually with cycling, which were primarily due to the low oxidative stability of VC on the surface of LiCoO2.

  10. Voltammetric detection of bisphenol a by a chitosan–graphene composite modified carbon ionic liquid electrode

    International Nuclear Information System (INIS)

    In this paper 1-ethyl-3-methylimidazolium tetrafluoroborate based carbon ionic liquid electrode (CILE) was fabricated and further modified with chitosan (CTS) and graphene (GR) composite film. The fabricated CTS-GR/CILE was further used for the investigation on the electrochemical behavior of bisphenol A (BPA) by cyclic voltammetry and differential pulse voltammetry. A well-defined anodic peak appeared at 0.436 V in 0.1 mol/L pH 8.0 Britton–Robinson buffer solution, which was attributed to the electrooxidation of BPA on the modified electrode. The electrochemical parameters of BPA on the modified electrode were calculated with the results of the charge transfer coefficient (α) as 0.662 and the apparent heterogeneous electron transfer rate constant (ks) as 1.36 s−1. Under the optimal conditions, a linear relationship between the oxidation peak current of BPA and its concentration can be obtained in the range from 0.1 μmol/L to 800.0 μmol/L with the limit of detection as 2.64 × 10−8 mol/L (3σ). The CTS-GR/CILE was applied to the detection of BPA content in plastic products with satisfactory results. - Highlights: ► A graphene modified carbon ionic liquid electrode was fabricated and characterized. ► Electrochemical behaviors of bisphenol A were investigated. ► Bisphenol A was detected by the proposed electrode.

  11. Ionic liquid modified carbon paste electrode and investigation of its electrocatalytic activity to hydrogen peroxide

    Indian Academy of Sciences (India)

    Erhan Canbay; Hayati Türkmen; Erol Akyilmaz

    2014-05-01

    This paper reports on the preparation and advantages of novel amperometric biosensors in the presence of hydrophobic ionic liquid (IL), 1-methyl-3-butylimidazolium bromide ([MBIB]). Carbon paste bio-sensor has been constructed by entrapping horseradish peroxidase in graphite and IL mixed with paraffin oil as a binder. The resulting IL/graphite material brings new capabilities for electrochemical devices by combining the advantages of ILs composite electrodes. Amounts of H2O2 were amperometrically detected by monitoring current values at reduction potential (–0.15 V) of K3Fe(CN)6. Decrease in biosensor responses were linearly related to H2O2 concentrations between 10 and 100 M with 2 s response time. Limit of detection of the biosensor were calculated to be 3.98 M for H2O2. In the optimization studies of the biosensor some parameters such as optimum pH, optimum temperature, enzyme amount, interference effects of some substances on the biosensor response, reproducibility and storage stability were carried out. The promising results are ascribed to the use of an ionic liquid, which forms an excellent charge-transfer bridge and wide electrochemical windows in the bulk of carbon paste electrode.

  12. Electrochemically reduced graphene modified carbon ionic liquid electrode for the sensitive sensing of rutin

    Energy Technology Data Exchange (ETDEWEB)

    Gao Feng [Fujian Province University Key Laboratory of Analytical Science, Department of Chemistry and Environment Science, Zhangzhou Normal University, Zhangzhou 363000 (China); Qi Xiaowei [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Cai Xili; Wang Qingxiang; Gao Fei [Fujian Province University Key Laboratory of Analytical Science, Department of Chemistry and Environment Science, Zhangzhou Normal University, Zhangzhou 363000 (China); Sun Wei, E-mail: sunwei@qust.edu.cn [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China)

    2012-05-31

    In this paper a graphene (GR) modified carbon ionic liquid electrode that was obtained by one-step potentiostatic electroreduction of a graphene oxide solution was described. The resulting electrode displayed excellent electrochemical performance due to the formation of highly conductive GR film on the electrode surface. Electrochemistry of rutin was carefully studied with a pair of well-defined redox peaks appeared in pH 2.5 buffer solution. Rutin exhibited a diffusion-controlled two-electron and two-proton transfer reaction on the modified electrode with the electrochemical parameters calculated. The reduction peak currents are linearly related to rutin concentration in the concentration range from 0.070 to 100.0 {mu}mol/L with a detection limit as low as 24.0 nmol/L (3{sigma}). The modified electrode displayed excellent selectivity with good stability, and was applied to the determination of rutin content in tablet, human serum and urine samples with satisfactory results. - Highlights: Black-Right-Pointing-Pointer Electroreduced graphene modified carbon ionic liquid electrode was obtained. Black-Right-Pointing-Pointer Electrochemical behaviors of rutin were investigated on the modified electrode. Black-Right-Pointing-Pointer Rutin in different samples were detected by the proposed electrode.

  13. Application of N-doped graphene modified carbon ionic liquid electrode for direct electrochemistry of hemoglobin

    International Nuclear Information System (INIS)

    Nitrogen-doped graphene (NG) was synthesized and used for the investigation on direct electrochemistry of hemoglobin (Hb) with a carbon ionic liquid electrode as the substrate electrode. Due to specific characteristics of NG such as excellent electrocatalytic property and large surface area, direct electron transfer of Hb was realized with enhanced electrochemical responses appearing. Electrochemical behaviors of Hb on the NG modified electrode were carefully investigated with the electrochemical parameters calculated. The Hb modified electrode exhibited excellent electrocatalytic reduction activity toward different substrates, such as trichloroacetic acid and H2O2, with wider dynamic range and lower detection limit. These findings show that NG can be used for the preparation of chemically modified electrodes with improved performance and has potential applications in electrochemical sensing. - Graphical abstract: The utilization of N-doped graphene enables direct electrochemistry of hemoglobin with a pair of well-defined redox peaks appearing. - Highlights: • Nitrogen-doped graphene (NG) was synthesized by a solvothermal method. • NG was used for the investigation on direct electrochemistry of hemoglobin with carbon ionic liquid electrode. • The Hb modified electrode exhibited excellent electrocatalytic activity toward different substrates

  14. Application of N-doped graphene modified carbon ionic liquid electrode for direct electrochemistry of hemoglobin

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Wei, E-mail: swyy26@hotmail.com [College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China); Dong, Lifeng, E-mail: donglifeng@qust.edu.cn [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Department of Physics, Astronomy, and Materials Science, Missouri State University, Springfield, MO 65897 (United States); Deng, Ying; Yu, Jianhua [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Wang, Wencheng [College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China); Zhu, Qianqian [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China)

    2014-06-01

    Nitrogen-doped graphene (NG) was synthesized and used for the investigation on direct electrochemistry of hemoglobin (Hb) with a carbon ionic liquid electrode as the substrate electrode. Due to specific characteristics of NG such as excellent electrocatalytic property and large surface area, direct electron transfer of Hb was realized with enhanced electrochemical responses appearing. Electrochemical behaviors of Hb on the NG modified electrode were carefully investigated with the electrochemical parameters calculated. The Hb modified electrode exhibited excellent electrocatalytic reduction activity toward different substrates, such as trichloroacetic acid and H{sub 2}O{sub 2}, with wider dynamic range and lower detection limit. These findings show that NG can be used for the preparation of chemically modified electrodes with improved performance and has potential applications in electrochemical sensing. - Graphical abstract: The utilization of N-doped graphene enables direct electrochemistry of hemoglobin with a pair of well-defined redox peaks appearing. - Highlights: • Nitrogen-doped graphene (NG) was synthesized by a solvothermal method. • NG was used for the investigation on direct electrochemistry of hemoglobin with carbon ionic liquid electrode. • The Hb modified electrode exhibited excellent electrocatalytic activity toward different substrates.

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

    Directory of Open Access Journals (Sweden)

    Xiaolin Xie

    2013-06-01

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

  16. Ionic Liquids in Tribology

    Directory of Open Access Journals (Sweden)

    Ichiro Minami

    2009-06-01

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

  17. Direct electrochemistry of hemoglobin entrapped in dextran film on carbon ionic liquid electrode

    Indian Academy of Sciences (India)

    Xiaoqing Li; Yan Wang; Xiaoying Sun; Tianrong Zhan; Wei Sun

    2010-03-01

    Direct electrochemistry of hemoglobin (Hb) entrapped in the dextran (De) film on the surface of a room temperature ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6) modified carbon paste electrode (CILE) has been investigated. UV-Vis and FT-IR spectroscopy showed that Hb retained its native structure in the De film. Scanning electron microscopy (SEM) indicated an uniform film was formed on the electrode surface. Cyclic voltammetric experiments indicated that the electron transfer efficiency between Hb and the electrode was greatly improved due to the presence of the De film and ionic liquid, which provided a biocompatible and higher conductive interface. A pair of well-defined and quasi-reversible redox peak was obtained with the anodic and cathodic peaks located at -0.195 V and -0.355 V in pH 7.0 phosphate buffer solution, respectively. The electrochemical parameters were calculated by investigating the relationship of the peak potential with the scan rate. The fabricated De/Hb/CILE showed good electrocatalytic ability to the reduction of H2O2 with the linear concentration range from 4.0 × 10-6 to 1.5 × 10-5 mol/L and the apparent Michaelis-Menten constant ($K_{M}^{\\text{app}}$) for the electrocatalytic reaction was calculated as 0.17 M.

  18. Electrodeposited nickel oxide and graphene modified carbon ionic liquid electrode for electrochemical myglobin biosensor

    International Nuclear Information System (INIS)

    By using ionic liquid 1-hexylpyridinium hexafluorophosphate based carbon ionic liquid electrode (CILE) as the substrate electrode, graphene (GR) and nickel oxide (NiO) were in situ electrodeposited step by step to get a NiO/GR nanocomposite modified CILE. Myoglobin (Mb) was further immobilized on the surface of NiO/GR/CILE with a Nafion film to get the electrochemical sensor denoted as Nafion/Mb/NiO/GR/CILE. Cyclic voltammetric experiments indicated that a pair of well-defined quasi-reversible redox peaks appeared in pH 3.0 phosphate buffer solution with the formal peak potential (E0′) located at − 0.188 V (vs. SCE), which was the typical characteristics of Mb Fe(III)/Fe(II) redox couples. So the direct electron transfer of Mb was realized and promoted due to the presence of the NiO/GR nanocomposite on the electrode. Based on the cyclic voltammetric data, the electrochemical parameters of Mb on the modified electrode were calculated. The Mb modified electrode showed an excellent electrocatalytic activity towards the reduction of different substrates including trichloroacetic acid and H2O2. Therefore a third-generation electrochemical Mb biosensor based on NiO/GR/CILE was constructed with good stability and reproducibility. - Highlights: • Graphene and nickel oxide nanocomposites were prepared by electrodeposition. • Electrochemical myoglobin sensor was prepared on a nanocomposite modified electrode. • Direct electrochemistry and electrocatalysis of myglobin were realized

  19. Electrodeposited nickel oxide and graphene modified carbon ionic liquid electrode for electrochemical myglobin biosensor

    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; Deng, Ying; Li, Tongtong; Cheng, Yong [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Wang, Wencheng [College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China); Wang, Lei [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China)

    2014-07-01

    By using ionic liquid 1-hexylpyridinium hexafluorophosphate based carbon ionic liquid electrode (CILE) as the substrate electrode, graphene (GR) and nickel oxide (NiO) were in situ electrodeposited step by step to get a NiO/GR nanocomposite modified CILE. Myoglobin (Mb) was further immobilized on the surface of NiO/GR/CILE with a Nafion film to get the electrochemical sensor denoted as Nafion/Mb/NiO/GR/CILE. Cyclic voltammetric experiments indicated that a pair of well-defined quasi-reversible redox peaks appeared in pH 3.0 phosphate buffer solution with the formal peak potential (E{sup 0′}) located at − 0.188 V (vs. SCE), which was the typical characteristics of Mb Fe(III)/Fe(II) redox couples. So the direct electron transfer of Mb was realized and promoted due to the presence of the NiO/GR nanocomposite on the electrode. Based on the cyclic voltammetric data, the electrochemical parameters of Mb on the modified electrode were calculated. The Mb modified electrode showed an excellent electrocatalytic activity towards the reduction of different substrates including trichloroacetic acid and H{sub 2}O{sub 2}. Therefore a third-generation electrochemical Mb biosensor based on NiO/GR/CILE was constructed with good stability and reproducibility. - Highlights: • Graphene and nickel oxide nanocomposites were prepared by electrodeposition. • Electrochemical myoglobin sensor was prepared on a nanocomposite modified electrode. • Direct electrochemistry and electrocatalysis of myglobin were realized.

  20. Scanning Electron Microscope Observation of Carbon Nanotubes with Room Temperature Ionic Liquids: Effect of Their Hydrophilicities.

    Science.gov (United States)

    Hyono, Atsushi; Abe, Shigeaki; Kawai, Koji; Yonezawa, Tetsu

    2015-11-01

    In this study, we succeeded in acquiring scanning electron microscope (SEM) images of carbon nanotube (CNT) derivatives with different surface properties based on an electro-conductive pretreatment using a room temperature ionic liquid (IL). The quality of the obtained SEM images depended on their surface properties and the hydrophilicities of IL used. When the hydrophilicities of both the sample surface and the IL were close, the obtained SEM images had a high resolution. In contrast, SEM imges of samples pretreated with an IL, which had different hydrophilicities from the sample, was observed with low resolution and low quality. This result suggests that the relationship between both hydrophilicities is the dominant factor for this visualization method. PMID:26726681

  1. Ionic liquid coated single-walled carbon nanotube buckypaper as supercapacitor electrode

    Institute of Scientific and Technical Information of China (English)

    Chao Zheng; Weizhong Qian; Yuntao Yu; Fei Wei

    2013-01-01

    Effect of stacking structure of single-walled carbon nanotubes (SWCNTs) on its performance as electrode of supercapacitor was investigated in the present work.Considering SWCNTs easily formed bundles due to strong van de Waals attraction between tubes,we proposed first dispersion of SWCNTs by ionic liquids (ILs) of 1-ethyl-3-methyl imidazolium tetrafluoroborate (EMIMBF4),followed by fabrication of buckypaper by compression.The debundling effect of ILs on SWCNTs increased the interface between electrode and electrolyte,decreased electrical resistance,and,consequently,increased performance of the supercapacitor.Since ILs,used to disperse SWCNTs,also functioned as electrolyte in supercapacitor,our method is a simple way to prepare buckypaper electrode with high performance.

  2. "Unrolling" multi-walled carbon nanotubes with ionic liquids: application as fillers in epoxy-based nanocomposites

    Czech Academy of Sciences Publication Activity Database

    Kleinschmidt, A. C.; Donato, R. K.; Perchacz, Magdalena; Beneš, Hynek; Štengl, Václav; Amico, S. C.; Schrekker, H. S.

    2014-01-01

    Roč. 4, č. 82 (2014), s. 43436-43443. ISSN 2046-2069 R&D Projects: GA ČR(CZ) GA14-05146S Institutional support: RVO:61389013 ; RVO:61388980 Keywords : carbon nanotubes * ionic liquids * epoxy Subject RIV: CD - Macromolecular Chemistry; CA - Inorganic Chemistry (UACH-T) Impact factor: 3.840, year: 2014

  3. Hydrophobic ionic liquids

    Science.gov (United States)

    Koch, Victor R.; Nanjundiah, Chenniah; Carlin, Richard T.

    1998-01-01

    Ionic liquids having improved properties for application in non-aqueous batteries, electrochemical capacitors, electroplating, catalysis and chemical separations are disclosed. Exemplary compounds have one of the following formulas: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are either H; F; separate alkyl groups of from 1 to 4 carbon atoms, respectively, or joined together to constitute a unitary alkylene radical of from 2 to 4 carbon atoms forming a ring structure converging on N; or separate phenyl groups; and wherein the alkyl groups, alkylene radicals or phenyl groups may be substituted with electron withdrawing groups, preferably F--, Cl--, CF.sub.3 --, SF.sub.5 --, CF.sub.3 S--, (CF.sub.3).sub.2 CHS-- or (CF.sub.3).sub.3 CS--; and X.sup.- is a non-Lewis acid-containing polyatomic anion having a van der Waals volume exceeding 100 .ANG..sup.3.

  4. Functional ionic liquids

    International Nuclear Information System (INIS)

    In the thesis at hand, new functional ionic liquids were investigated. Main focus was attended to their structure property relations and the structural features leading to a decrease of the melting point. New compounds of the type 1-butyl-3-methylimidazolium tris(N,Ndialkyldithiocarbamato) uranylate with variously substituated dithiocarbamato ligands were synthesized and characterized. Ligands with asymmetrical substitution pattern proved to be most suitable for ionic liquid formation. The single-crystal X-ray structures revealed the interactions in the solid state. Here, the first spectroscopic investigation of the U-S bond in sulfur donated uranyl complexes, up to now only observed in single-crystal X-ray structures, is presented, and the participation of the uranium f-orbitals is shown by theoretical calculations. Electrochemical investigations showed the accessibility of the respective UVO2+ compounds. As well, ionic liquids with [FeCl4]- and [Cl3FeOFeCl3]2- as anion were synthesized. Both of these anions contain high-spin Fe(III) centres in distorted tetrahedral environment, but exhibit different magnetic behaviour. The tetrachloroferrates show the usual paramagnetism, the m-oxobis(trichloroferrate) exhibits unexpectedly strong antiferromagnetic coupling, as was observed by NMR experiments and susceptibility measurements. To investigate structure-property relations in functionalized ionic liquids, a set of protic, primary alkylammonium and aprotic, quarternary trimethylalkylammonium based ionic liquids was synthesized, and characterized. The length of the alkyl chain was systematically varied, and all compounds were synthesized with and without hydroxyl group, as well as formate and bis(triflyl)amide salts, aiming at getting insight into the influence of the different structure parts on the respective ionic liquid's properties.

  5. Epoxy resin/phosphonium ionic liquid/carbon nanofiller systems: Chemorheology and properties

    Directory of Open Access Journals (Sweden)

    H. Maka

    2014-10-01

    Full Text Available Epoxy nanocomposites with commercial carbon nanotubes (CNT or graphene (GN have been prepared using phosphonium ionic liquid [trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl phosphinate, IL-f]. IL-f served simultaneously as nanofiller dispersing medium and epoxy resin catalytic curing agent. An influence of IL-f/epoxy weight ratio (3, 6 and 9/100, phr, carbon nanofiller type and content on viscosity of epoxy compositions during storage at ambient temperature was evaluated. Curing process was controlled for neat and CNT or GN modified epoxy compositions (0.25-1.0 wt.% load using differential scanning calorimetry and rheometry. Epoxy nanocomposites exhibited slightly increased glass transition temperature values (146 to 149°C whereas tan δ and storage modulus decreased (0.30 to 0.27 and 2087 to 1070 MPa, respectively as compared to reference material. Crosslink density regularly decreased for composites with increasing CNT content (11 094 to 7 020 mol/m3. Electrical volume resistivity of the nanocomposites was improved in case of CNT to 4•101 Ω•m and GN to 2•105 Ω•m (nanofiller content 1 wt.%. Flame retardancy was found for modified epoxy materials with as low GN and phosphorus content as 0.25 and 0.7 wt.%, respectively (increase of limiting oxygen index to 26.5%.

  6. Three-dimensional graphitized carbon nanovesicles for high-performance supercapacitors based on ionic liquids.

    Science.gov (United States)

    Peng, Chengxin; Wen, Zubiao; Qin, Yao; Schmidt-Mende, Lukas; Li, Chongzhong; Yang, Shihe; Shi, Donglu; Yang, Jinhu

    2014-03-01

    Three-dimensional nanoporous carbon with interconnected vesicle-like pores (1.5-4.2 nm) has been prepared through a low-cost, template-free approach from petroleum coke precursor by KOH activation. It is found that the thin pore walls are highly graphitized and consist of only three to four layers of graphene, which endows the material with an unusually high specific surface area (2933 m(2)  g(-1) ) and good conductivity. With such unique structural characteristics, if used as supercapacitor electrodes in ionic liquid (IL) electrolytes, the graphitized carbon nanovesicle (GCNV) material displays superior performance, such as high energy densities up to 145.9 Wh kg(-1) and a high combined energy-power delivery, and an energy density of 97.6 Wh kg(-1) can be charged in 47 s at 60 °C. This demonstrates that the energy output of the GCNV-based supercapacitors is comparable to that of batteries, and the power output is one order of magnitude higher. Moreover, the synergistic effect of the GCNVs and the IL electrolyte on the extraordinary performance of the GCNV supercapacitors has been analyzed and discussed. PMID:24474720

  7. Ionic liquid based EDLCs: influence of carbon porosity on electrochemical performance.

    Science.gov (United States)

    Noofeli, Asa; Hall, Peter J; Rennie, Anthony J R

    2014-01-01

    Electrochemical double layer capacitors (EDLCs) are a category of supercapacitors; devices that store charge at the interface between electrodes and an electrolyte. Currently available commercial devices have a limited operating potential that restricts their energy and power densities. Ionic liquids (ILs) are a promising alternative electrolyte as they generally exhibit greater electrochemical stabilities and lower volatility. This work investigates the electrochemical performance of EDLCs using ILs that combine the bis(trifluoromethanesulfonyl)imide anion with sulfonium and ammonium based cations. Different activated carbon materials were employed to also investigate the influence of varying pore size on electrochemical performance. Electrochemical impedance spectroscopy (EIS) and constant current cycling at different rates were used to assess resistance and specific capacitance. In general, greater specific capacitances and lower resistances were found with the sulfonium based ILs studied, and this was attributed to their smaller cation volume. Comparing electrochemical stabilities indicated that significantly higher operating potentials are possible with the ammonium based ILs. The marginally smaller sulfonium cation performed better with the carbon exhibiting the largest pore width, whereas peak performance of the larger sulfonium cation was associated with a narrower pore size. Considerable differences between the performance of the ammonium based ILs were observed and attributed to differences not only in cation size but also due to the inclusion of a methoxyethyl group. The improved performance of the ether bond containing IL was ascribed to electron donation from the oxygen atom influencing the charge density of the cation and facilitating cation-cation interactions. PMID:25427314

  8. Electrochemical behavior of labetalol at an ionic liquid modified carbon paste electrode and its electrochemical determination

    Directory of Open Access Journals (Sweden)

    Zhang Yan-Mei

    2013-01-01

    Full Text Available Electrochemical behavior of labetalol (LBT at carbon paste electrode (CPE and an ionic liquid1-benzyl-3-methylimidazolehexafluorophosphate([BnMIM]PF6modified carbon paste electrode([BnMIM]PF6/CPEin Britton-Robinson buffer solution (pH 2.0 was investigated by cyclic voltammetry (CV and square wave voltammetric (SWV. The experimental results showed that LBT at both the bare CPE and [BnMIM]PF6/CPEshowed an irreversible oxidation process, but at [BnMIM]PF6/CPE its oxidation peak current increased greatly and the oxidation peak potential shifted negatively. The electrode reaction process is a diffusion-controlled process involving one electron transferring accompanied by a participation of one proton at [BnMIM]PF6/CPE. At the same time, the electrochemical kinetic parameters were determined. Under the optimized electrochemical experimental conditions, the oxidation peak currents were proportional to LBT concentration in the range of 7.0 x 10-6-1.0 x 10-4 mol L-1 with the limit of detection(LOD, S/N=3 of 4.810 x 10-8 mol L-1and the limit of quantification(LOQ, S/N=10 of 1.60 x 10-7 mol L-1, respectively. The proposed method was successfully applied in the determination of LBT content in commercial tablet samples.

  9. Lithium-sulfur batteries based on nitrogen-doped carbon and an ionic-liquid electrolyte.

    Science.gov (United States)

    Sun, Xiao-Guang; Wang, Xiqing; Mayes, Richard T; Dai, Sheng

    2012-10-01

    Nitrogen-doped mesoporous carbon (NC) and sulfur were used to prepare an NC/S composite cathode, which was evaluated in an ionic-liquid electrolyte of 0.5 M lithium bis(trifluoromethane sulfonyl)imide (LiTFSI) in methylpropylpyrrolidinium bis(trifluoromethane sulfonyl)imide ([MPPY][TFSI]) by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and cycle testing. To facilitate the comparison, a C/S composite based on activated carbon (AC) without nitrogen doping was also fabricated under the same conditions. Compared with the AC/S composite, the NC/S composite showed enhanced activity toward sulfur reduction, as evidenced by the lower onset sulfur reduction potential, higher redox current density in the CV test, and faster charge-transfer kinetics, as indicated by EIS measurements. At room temperature under a current density of 84 mA g(-1) (C/20), the battery based on the NC/S composite exhibited a higher discharge potential and an initial capacity of 1420 mAh g(-1), whereas the battery based on the AC/S composite showed a lower discharge potential and an initial capacity of 1120 mAh g(-1). Both batteries showed similar capacity fading with cycling due to the intrinsic polysulfide solubility and the polysulfide shuttle mechanism; capacity fading can be improved by further cathode modification. PMID:22847977

  10. Ionic and Molecular Liquids

    DEFF Research Database (Denmark)

    Chaban, Vitaly V.; Prezhdo, Oleg

    2013-01-01

    Because of their outstanding versatility, room-temperature ionic liquids (RTILs) are utilized in an ever increasing number of novel and fascinating applications, making them the Holy Grail of modern materials science. In this Perspective, we address the fundamental research and prospective...

  11. Reduction of Carbon Dioxide to Formate at Low Overpotential Using a Superbase Ionic Liquid

    OpenAIRE

    Hollingsworth, Nathan; Taylor, S. F. Rebecca; Galante, Miguel T.; Johan JACQUEMIN; Longo, Claudia; Holt, Katherine B.; Nora H. de Leeuw; Hardacre, Christopher

    2015-01-01

    A new low-energy pathway is reported for the electrochemical reduction of CO2 to formate and syngas at low overpotentials, utilizing a reactive ionic liquid as the solvent. The superbasic tetraalkyl phosphonium ionic liquid [P66614][124Triz] is able to chemisorb CO2 through equimolar binding of CO2 with the 1,2,4-triazole anion. This chemisorbed CO2 can be reduced at silver electrodes at overpotentials as low as 0.17 V, forming formate. In contrast, physically absorbed CO2 within the same ion...

  12. Applications of functionalized ionic liquids

    Institute of Scientific and Technical Information of China (English)

    LI Xuehui; ZHAO Dongbin; FEI Zhaofu; WANG Lefu

    2006-01-01

    Recent developments of the synthesis and applications of functionalized ionic liquids(including dual-functionalized ionic liquids) have been highlighted in this review. Ionic liquids are attracting attention as alternative solvents in green chemistry, but as more functionalized ILs are prepared, a greater number of applications in increasingly diverse fields are found.

  13. Radiation chemistry of ionic liquids

    International Nuclear Information System (INIS)

    Ionic liquids are expected as a replacement of processing media for the nuclear fuel cycle. Therefore, an understanding of the interactions of ionizing radiations and photons with ionic liquids is strongly needed. However, the radiation chemistry of ionic liquids is still a relatively unexplored topic although there has been a significant increase in the number of researchers in the field recently. (author)

  14. Voltammetric determination of norepinephrine in the presence of acetaminophen using a novel ionic liquid/multiwall carbon nanotubes paste electrode

    International Nuclear Information System (INIS)

    A novel multiwall carbon nanotubes (MWCNTs) modified carbon ionic liquid electrode (CILE) was fabricated and used to investigate the electrochemical behavior of norepinephrine (NP). MWCNTs/CILE was prepared by mixing hydrophilic ionic liquid, 1-methyl-3-butylimidazolium bromide (MBIDZBr), with graphite powder, MWCNTs, and liquid paraffin. The fabricated MWCNTs/CILE showed great electrocatalytic ability to the oxidation of NE. The electron transfer coefficient, diffusion coefficient, and charge transfer resistant (Rct) of NE at the modified electrode were calculated. Differential pulse voltammetry of NE at the modified electrode exhibited two linear dynamic ranges with slopes of 0.0841 and 0.0231 μA/μM in the concentration ranges of 0.3 to 30.0 μM and 30.0 to 450.0 μM, respectively. The detection limit (3σ) of 0.09 μM NP was achieved. This modified electrode exhibited a good ability for well separated oxidation peaks of NE and acetaminophen (AC) in a buffer solution, pH 7.0. The proposed sensor was successfully applied for the determination of NE in human urine, pharmaceutical, and serum samples. Highlights: ► Electrochemical behavior of norepinephrine study using carbon ionic liquid electrode ► This sensor resolved the overlap response of norepinephrine and acetaminophen. ► This sensor is also used for the determination of above compounds in real samples.

  15. Voltammetric determination of norepinephrine in the presence of acetaminophen using a novel ionic liquid/multiwall carbon nanotubes paste electrode

    Energy Technology Data Exchange (ETDEWEB)

    Salmanpour, Sadegh [Department of Chemistry, Sari Branch, Islamic Azad University, Sari (Iran, Islamic Republic of); Tavana, Toktam [Department of Chemistry, Qaemshahr Branch, Islamic Azad University, Qaemshahr (Iran, Islamic Republic of); Pahlavan, Ali [Department of Physics, Science and Research Branch, Islamic Azad University, Mazandaran (Iran, Islamic Republic of); Khalilzadeh, Mohammad A., E-mail: khalilzadeh73@yahoo.com [Department of Chemistry, Science and Research Branch, Islamic Azad University, Mazandaran (Iran, Islamic Republic of); Ensafi, Ali A. [Department of Chemistry, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of); Karimi-Maleh, Hassan, E-mail: h.karimi.maleh@gmail.com [Department of Chemistry, Science and Research Branch, Islamic Azad University, Mazandaran (Iran, Islamic Republic of); Beitollahi, Hadi [Environment Department, Research Institute of Environmental Sciences, International Center for Science, High Technology and Environmental Sciences, Kerman (Iran, Islamic Republic of); Kowsari, Elaheh [Department of Chemistry, Amirkabir University of Technology, No. 424, Hafez Avenue, Tehran (Iran, Islamic Republic of); Zareyee, Daryoush [Department of Chemistry, Qaemshahr Branch, Islamic Azad University, Qaemshahr (Iran, Islamic Republic of)

    2012-10-01

    A novel multiwall carbon nanotubes (MWCNTs) modified carbon ionic liquid electrode (CILE) was fabricated and used to investigate the electrochemical behavior of norepinephrine (NP). MWCNTs/CILE was prepared by mixing hydrophilic ionic liquid, 1-methyl-3-butylimidazolium bromide (MBIDZBr), with graphite powder, MWCNTs, and liquid paraffin. The fabricated MWCNTs/CILE showed great electrocatalytic ability to the oxidation of NE. The electron transfer coefficient, diffusion coefficient, and charge transfer resistant (R{sub ct}) of NE at the modified electrode were calculated. Differential pulse voltammetry of NE at the modified electrode exhibited two linear dynamic ranges with slopes of 0.0841 and 0.0231 {mu}A/{mu}M in the concentration ranges of 0.3 to 30.0 {mu}M and 30.0 to 450.0 {mu}M, respectively. The detection limit (3{sigma}) of 0.09 {mu}M NP was achieved. This modified electrode exhibited a good ability for well separated oxidation peaks of NE and acetaminophen (AC) in a buffer solution, pH 7.0. The proposed sensor was successfully applied for the determination of NE in human urine, pharmaceutical, and serum samples. Highlights: Black-Right-Pointing-Pointer Electrochemical behavior of norepinephrine study using carbon ionic liquid electrode Black-Right-Pointing-Pointer This sensor resolved the overlap response of norepinephrine and acetaminophen. Black-Right-Pointing-Pointer This sensor is also used for the determination of above compounds in real samples.

  16. Ionic Liquid for in situ Vis/NIR and Raman Spectroelectrochemistry: Doping of Carbon Nanostructures

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav; Dunsch, L.

    2003-01-01

    Roč. 4, - (2003), s. 944-950. ISSN 1439-4235 R&D Projects: GA AV ČR IAA4040306 Institutional research plan: CEZ:AV0Z4040901 Keywords : ionic liquids * nanotubes * Raman spectroscopy Subject RIV: CG - Electrochemistry Impact factor: 3.316, year: 2003

  17. Anisometric Charge Dependent Swelling of Porous Carbon in an Ionic Liquid

    CERN Document Server

    Kaasik, F; Hantel, M M; Perre, E; Aabloo, A; Lust, E; Bazant, M Z; Presser, V

    2013-01-01

    In situ electrochemical dilatometry was used to study, for the first time, the expansion behavior of a porous carbon electrode in a pure ionic liquid, 1-ethyl-3-methyl-imidazolium-tetrafluoroborate. For a single electrode, an applied potential of -2 V and +2 V against the potential of zero charge resulted in maximum strain of 1.8 % and 0.5 %, respectively. During cyclic voltammetry, the characteristic expansion behavior strongly depends on the scan rate, with increased scan rates leading to a decrease of the expansion. Chronoamperometry was used to determine the equilibrium specific capacitance and expansion. The obtained strain versus accumulated charge relationship can be fitted with a simple quadratic function. Cathodic and anodic expansion data collapses on one parabola when normalizing the surface charge by the ratio of ion volume and average pore size. There is also a transient spike in the height change when polarity is switched from positive to negative that is not observed when changing the potential...

  18. An electrochemical in situ study of freezing and thawing of ionic liquids in carbon nanopores.

    Science.gov (United States)

    Weingarth, Daniel; Drumm, Robert; Foelske-Schmitz, Annette; Kötz, Rüdiger; Presser, Volker

    2014-10-21

    Room temperature ionic liquids (RTILs) are an emerging class of electrolytes enabling high cell voltages and, in return, high energy density of advanced supercapacitors. Yet, the low temperature behavior, including freezing and thawing, is little understood when ions are confined in the narrow space of nanopores. This study shows that RTILs may show a tremendously different thermal behavior when comparing bulk with nanoconfined properties as a result of the increased surface energy of carbon pore walls. In particular, a continuous increase in viscosity is accompanied by slowed-down charge-discharge kinetics as seen with in situ electrochemical characterization. Freezing reversibly collapses the energy storage ability and thawing fully restores the initial energy density of the material. For the first time, a different thermal behavior in positively and negatively polarized electrodes is demonstrated. This leads to different freezing and melting points in the two electrodes. Compared to bulk, RTILs in the confinement of electrically charged nanopores show a high affinity for supercooling; that is, the electrode may freeze during heating. PMID:25201074

  19. Development of a sensitive and selective Riboflavin sensor based on carbon ionic liquid electrode

    Energy Technology Data Exchange (ETDEWEB)

    Safavi, Afsaneh, E-mail: safavi@chem.susc.ac.ir [Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of); Maleki, Norouz; Ershadifar, Hamid; Tajabadi, Fariba [Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of)

    2010-08-03

    The electrochemical properties of Riboflavin adsorbed on carbon ionic liquid electrode (CILE) were studied by cyclic voltammetry. A film with a surface coverage of up to 3.3 x 10{sup -9} mol cm{sup -2} was formed after 10 min exposure time. Electron transfer coefficient and rate constant of electron transfer across the modified electrode were found to be 0.43 and 3.03 s{sup -1}, respectively. Differential pulse voltammetry was used for the determination of Riboflavin. Two linear working ranges of 0.8-110 nM and 0.11-1.0 {mu}M were obtained with correlation coefficients of 0.998 and 0.996, respectively. The experimental detection limit was obtained as 0.1 nM. The relative standard deviation for five replicate analyses was 4.7%. Other soluble vitamins had no significant interferences and the electrode was used for the determination of Riboflavin in pharmaceutical products, nutrition and beverages.

  20. Structure evolution of carbon black under ionic-liquid-assisted microwave irradiation

    International Nuclear Information System (INIS)

    The interactions between the carbon black (CB) and the ionic liquid (IL), 1-butyl-3-methyl-imiazolium hexafluorophosphate ([BMIM+][PF6-]), are firstly examined. The CB, mixed with the IL via simple blending, is then subjected to microwave (MW) irradiation to prepare the modified CB. The structure evolutions of the modified CB such as the microcrystalline structure and surface chemistry are revealed by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and pore analysis. After mixing but before MW irradiation, the microcrystalline arrangement of CB turns to be more ordering and microcrystalline size (La) to be a little bigger but with a limited degree. Under MW irradiation, the IL undergoes severe decomposition. The combination of localized high temperature (proposed to be higher than 425 deg. C) and the decomposition of the IL leads to substantial structure changes of the CB. The graphitization of the CB surface, the disordering of the microcrystalline and the decrease in La are disclosed. In addition, compared with the untreated CB, the CB treated with IL-assisted MW irradiation is found to have much higher volume of the smaller mesopore.

  1. Green chemical functionalization of multiwalled carbon nanotubes with poly({epsilon}-caprolactone) in ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Yang Yingkui, E-mail: yingkuiyang@gmail.com [Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan 430062 (China); Qiu Shengqiang; He Chengen; He Wenjie; Yu Linjuan [Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan 430062 (China); Xie Xiaolin, E-mail: xlxie@mail.hust.edu.cn [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2010-11-15

    Multiwalled carbon nanotubes (MWNTs) have been successfully functionalized by free radical addition of 4,4'-azobis(4-cyanopentanol) in aqueous media to generate the terminal-hydroxyl-modified MWNTs (MWNT-OH), followed by surface-initiated in situ ring-opening polymerization of {epsilon}-caprolactone in 1-butyl-3-methylimidazolium tetrafluoroborate (BmimBF{sub 4}) to obtain poly({epsilon}-caprolactone)-grafted MWNTs (MWNT-g-PCL). Spectroscopic methods in conjunction with electron microscopy clearly revealed that hairy PCL chains were chemically attached to the surface of MWNTs to form core-shell nanostructures with the latter as core and the former as shell. With increasing polymerization time from 2 to 8 h, the amount of the grafted-PCL synthesized in BmimBF{sub 4} varies from 30.6 to 62.7 wt%, which is clearly higher than that (41.5 wt%) obtained in 1,2-dichlorobenzene under comparable conditions (8 h). The proposed methodology here uses water and room temperature ionic liquids (RTILs) as the reaction media and promises a green chemical process for functionalizing nanotubes.

  2. Synthesis and Characterisation of Fluorescent Carbon Nanodots Produced in Ionic Liquids by Laser Ablation.

    Science.gov (United States)

    Castro, Hemerson P S; Souza, Virgínia S; Scholten, Jackson D; Dias, Janine H; Fernandes, Jesum A; Rodembusch, Fabiano S; Dos Reis, Roberto; Dupont, Jairton; Teixeira, Sérgio R; Correia, Ricardo R B

    2016-01-01

    Carbon nanodots (C-dots) with an average size of 1.5 and 3.0 nm were produced by laser ablation in different imidazolium ionic liquids (ILs), namely, 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF4 ), 1-n-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMI.NTf2 ) and 1-n-octyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (OMI.NTf2 ). The mean size of the nanoparticles is influenced by the imidazolium alkyl side chain but not by the nature of the anion. However, by varying the anion (BF4 vs. NTf2 ) it was possible to detect a significant modification of the fluorescence properties. The C-dots are much probably stabilised by an electrostatic layer of the IL and this interaction has played an important role with regard to the formation, stabilisation and photoluminescence properties of the nanodots. A tuneable broadband fluorescence emission from the colloidal suspension was observed under ultraviolet/visible excitation with fluorescence lifetimes fitted by a multi-exponential decay with average values around 7 ns. PMID:26558445

  3. Density, conductivity, viscosity, and excess properties of (pyrrolidinium nitrate-based Protic Ionic Liquid + propylene carbonate) binary mixture

    OpenAIRE

    Pires, J; Timperman, L.; Jacquemin, J.; A. Balducci; Anouti, M.

    2013-01-01

    Density, ?, viscosity, ?, and conductivity, s, measurements of binary mixtures containing the pyrrolidinium nitrate Protic Ionic Liquid (PIL) and propylene carbonate (PC), are determined at the atmospheric pressure as a function of the temperature from (283.15 to 353.15) K and within the whole composition range. The temperature dependence of both the viscosity and conductivity of each mixture exhibits a non-Arrhenius behaviour, but is correctly fitted by using the Vogel–Tamman–Fulcher (VTF) e...

  4. Molecular Dynamics Simulation for the Binary Mixtures of High Pressure Carbon Dioxide and Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    徐君臣; 王松; 喻文; 徐琴琴; 王伟彬; 银建中

    2014-01-01

    Molecular dynamics simulation with an all-atom force field has been carried out on the two binary sys-tems of [bmim][PF6]-CO2 and [bmim][NO3]-CO2 to study the transport properties, volume expansion and micro-structures. It was found that addition of CO2 in the liquid phase can greatly decrease the viscosity of ionic liquids (ILs) and increase their diffusion coefficient obviously. Furthermore, the volume expansion of ionic liquids was found to increase with the increase of the mole fraction of CO2 in the liquid phase but less than 35%for the two simulated systems, which had a significant difference with CO2 expanded organic solvents. The main reason was that there were some void spaces inter and intra the molecules of ionic liquids. Finally, site to site radial distribution functions and corresponding number integrals were investigated and it was found that the change of microstructures of ILs by addition CO2 had a great influence on the properties of ILs.

  5. Cyclic phosphonium ionic liquids

    Directory of Open Access Journals (Sweden)

    Sharon I. Lall-Ramnarine

    2014-01-01

    Full Text Available Ionic liquids (ILs incorporating cyclic phosphonium cations are a novel category of materials. We report here on the synthesis and characterization of four new cyclic phosphonium bis(trifluoromethylsulfonylamide ILs with aliphatic and aromatic pendant groups. In addition to the syntheses of these novel materials, we report on a comparison of their properties with their ammonium congeners. These exemplars are slightly less conductive and have slightly smaller self-diffusion coefficients than their cyclic ammonium congeners.

  6. Wettability by Ionic Liquids.

    Science.gov (United States)

    Liu, Hongliang; Jiang, Lei

    2016-01-01

    Ionic liquids (ILs) have become particularly attractive recently because they have demonstrated themselves to be important construction units in the broad fields of chemistry and materials science, from catalysis and synthesis to analysis and electrochemistry, from functional fluids to clean energy, from nanotechnology to functional materials. One of the greatest issues that determines the performance of ILs is the wettability of correlated surfaces. In this concept article, the key developments and issues in IL wettability are surveyed, including the electrowetting of ILs in gas-liquid-solid systems and liquid-liquid-solid systems, ILs as useful probe fluids, the superwettability of Ils, and future directions in IL wettability. This should generate extensive interest in the field and encourage more scientists to engage in this area to tackle its scientific challenges. PMID:26619157

  7. Electrochemical horseradish peroxidase biosensor based on dextran-ionic liquid-V2O5 nanobelt composite material modified carbon ionic liquid electrode

    International Nuclear Information System (INIS)

    Direct electrochemistry of horseradish peroxidase (HRP) was realized in a dextran (De), 1-ethyl-3-methylimidazolium ethylsulphate ([EMIM]EtOSO3) and V2O5 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-V2O5 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-1. The proposed electrode is valuable for the third-generation electrochemical biosensor.

  8. Green synthesis of polymer monoliths incorporated with carbon nanotubes in room temperature ionic liquid and deep eutectic solvents.

    Science.gov (United States)

    Zhang, Li-Shun; Gao, Shu-Ping; Huang, Yan-Ping; Liu, Zhao-Sheng

    2016-07-01

    In this work, an efficient method to prepare polymer monoliths with incorporated carbon nanotubes in a mixture of room temperature ionic liquid and deep eutectic solvents was developed. With assistance of the binary green solvent, 1-butyl-3-methylimidazolium tetrafluoroborate and choline chloride/ethylene glycol, single-walled carbon nanotubes were dispersed successfully in pre-polymerization mixture without need of oxidative cutting of carbon nanotubes, which may allow depletion of the emission of volatile organic compounds into environment. The novel single-walled carbon nanotubes monolith was evaluated by capillary electrochromatography. Compared with the monolith made without single-walled carbon nanotubes, the monolith with the incorporation of single-walled carbon nanotubes exhibited high column efficiency (251,000plates/m) in the chromatographic separation. The morphology of the monolith can be tuned by the composition of mixture of ionic liquids and deep eutectic solvents to afford good column permeability and excellent separation ability for small molecules of alkyl phenones and alkyl benzenes. The results demonstrated that the method is a green strategy for the fabrication of multifunctional polymer monoliths. PMID:27154683

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

    Directory of Open Access Journals (Sweden)

    Eero eSalminen

    2014-02-01

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

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

    Science.gov (United States)

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

    2014-02-01

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

  11. Solubility dynamic of methyl yellow and carbon black in microemulsions and lamellar liquid crystal of water, non ionic surfactants and cyclohexane system

    Science.gov (United States)

    Amran, A.; Harfianto, R.; Dewi, W. Y.; Beri, D.; Putra, A.

    2016-02-01

    Solubility dynamics of methyl yellow and carbon black in microemulsions and liquid crystals of water, non-ionic surfactants and cyclohexane system, have been investigated. Actually, solubility dynamics of these dyes both in microemulsion (w/o microemulsions) and the lamellar liquid crystal (LLC) were strongly related to the chemical composition, nature and characteristics of microemulsions and the lamellar liquid crystals.

  12. Electrochemical reduction of aromatic ketones in 1-butyl-3-methylimidazolium-based ionic liquids in the presence of carbon dioxide: the influence of the ketone substituent and the ionic liquid anion on bulk electrolysis product distribution.

    Science.gov (United States)

    Zhao, Shu-Feng; Horne, Mike; Bond, Alan M; Zhang, Jie

    2015-07-15

    Electrochemical reduction of aromatic ketones, including acetophenone, benzophenone and 4-phenylbenzophenone, has been undertaken in 1-butyl-3-methylimidazolium-based ionic liquids containing tetrafluoroborate ([BF4](-)), trifluoromethanesulfonate ([TfO](-)) and tris(pentafluoroethyl)trifluorophosphate ([FAP](-)) anions in the presence of carbon dioxide in order to investigate the ketone substituent effect and the influence of the acidic proton on the imidazolium cation (C2-H) on bulk electrolysis product distribution. For acetophenone, the minor products were dimers (50%) derived from proton coupled electron transfer reactions involving the electrogenerated radical anions and C2-H. In the cases of both acetophenone and benzophenone, the product distribution is essentially independent of the ionic liquid anion. By contrast, 4-phenylbenzophenone shows a product distribution that is dependent on the ionic liquid anion. Higher yields of carboxylic acids (∼40%) are obtained with [TfO](-) and [FAP](-) anions because in these ionic liquids the C2-H is less acidic, making the formation of alcohol less favourable. In comparison with benzophenone, a higher yield of carboxylic acid (>30% versus ∼15%) was obtained with 4-phenylbenzophenone in all ionic liquids due to the weaker basicity of 4-phenylbenzophenone radical anion. PMID:26136079

  13. IONIC LIQUIDS: PREPARATIONS AND LIMITATIONS

    OpenAIRE

    Dzulkefly Kuang Abdullah; Ahmad Adlie Shamsuri

    2010-01-01

    Ionic liquids are considered as an ideal alternative to volatile organic solvents and chemical industries in the future,because they are non-volatile. Ionic liquids are also considered as new novel chemical agents and widely regarded as agreener alternative to many commonly used solvents. Ionic liquids have been studied for a wide range of syntheticapplications and have attracted considerable interest for use as electrolytes in the areas of organic synthesis, catalysis,solar cell, fuel cells,...

  14. All-solid-state flexible supercapacitors based on papers coated with carbon nanotubes and ionic-liquid-based gel electrolytes

    International Nuclear Information System (INIS)

    All-solid-state flexible supercapacitors were fabricated using carbon nanotubes (CNTs), regular office papers, and ionic-liquid-based gel electrolytes. Flexible electrodes were made by coating CNTs on office papers by a drop-dry method. The gel electrolyte was prepared by mixing fumed silica nanopowders with ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][NTf2]). This supercapacitor showed high power and energy performance as a solid-state flexible supercapacitor. The specific capacitance of the CNT electrodes was 135 F g−1 at a current density of 2 A g−1, when considering the mass of active materials only. The maximum power and energy density of the supercapacitors were 164 kW kg−1 and 41 Wh kg−1, respectively. Interestingly, the solid-state supercapacitor with the gel electrolyte showed comparable performance to the supercapacitors with ionic-liquid electrolyte. Moreover, the supercapacitor showed excellent stability and flexibility. The CNT/paper- and gel-based supercapacitors may hold great potential for low-cost and high-performance flexible energy storage applications. (paper)

  15. Ionic liquids, electrolyte solutions including the ionic liquids, and energy storage devices including the ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Gering, Kevin L.; Harrup, Mason K.; Rollins, Harry W.

    2015-12-08

    An ionic liquid including a phosphazene compound that has a plurality of phosphorus-nitrogen units and at least one pendant group bonded to each phosphorus atom of the plurality of phosphorus-nitrogen units. One pendant group of the at least one pendant group comprises a positively charged pendant group. Additional embodiments of ionic liquids are disclosed, as are electrolyte solutions and energy storage devices including the embodiments of the ionic liquid.

  16. Understanding the effect of side groups in ionic liquids on carbon-capture properties: a combined experimental and theoretical effort

    OpenAIRE

    Yan, Fangyong; Lartey, Michael; Damodaran, Krishnan; Albenze, Erik; Thompson, Robert L.; Kim, Jihan; Haranczyk, Maciej; Nulwala, Hunaid B.; Luebke, David R.; Smit, Berend

    2013-01-01

    Ionic liquids are an emerging class of materials with applications in a variety of fields. Steady progress has been made in the creation of ionic liquids tailored to specific applications. However, the understanding of the underlying structure-property relationships has been slower to develop. As a step in the effort to alleviate this deficiency, the influence of side groups on ionic liquid properties has been studied through an integrated approach utilizing synthesis, experimental determinat...

  17. Coupling of Carbon Dioxide Stretch and Bend Vibrations Reveals Thermal Population Dynamics in an Ionic Liquid.

    Science.gov (United States)

    Giammanco, Chiara H; Kramer, Patrick L; Yamada, Steven A; Nishida, Jun; Tamimi, Amr; Fayer, Michael D

    2016-01-28

    The population relaxation of carbon dioxide dissolved in the room temperature ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EmimNTf2) was investigated using polarization-selective ultrafast infrared pump-probe spectroscopy and two-dimensional infrared (2D IR) spectroscopy. Due to the coupling of the bend with the asymmetric stretch, excitation of the asymmetric stretch of a molecule with a thermally populated bend leads to an additional peak, a hot band, which is red-shifted from the main asymmetric absorption band by the combination band shift. This hot band peak exchanges population with the main peak through the gain and loss of bend excitation quanta. The isotropic pump-probe signal originating from the unexcited bend state displays a fast, relatively small amplitude, initial growth followed by a longer time scale exponential decay. The signal is analyzed over its full time range using a kinetic model to determine both the vibrational lifetime (the final decay) and rate constant for the loss of the bend energy. This bend relaxation manifests as the fast initial growth of the stretch/no bend signal because the hot band (stretch with bend) is "over pumped" relative to the ground state equilibrium. The nonequilibrium pumping occurs because the hot band has a larger transition dipole moment than the stretch/no bend peak. The system is then prepared, utilizing an acousto-optic mid-infrared pulse shaper to cut a hole in the excitation pulse spectrum, such that the hot band is not pumped. The isotropic pump-probe signal from the stretch/no bend state is altered because the initial excited state population ratio has changed. Instead of a growth due to relaxation of bend quanta, a fast initial decay is observed because of thermal excitation of the bend. Fitting this curve gives the rate constant for thermal excitation of the bend and the lifetime, which agree with those determined in the pump-probe experiments without frequency

  18. Mixtures of ionic liquid and organic carbonate as electrolyte with improved safety and performance for rechargeable lithium batteries

    International Nuclear Information System (INIS)

    Highlights: → Mixtures of PC, PYR14TFSI and LiTFSI as electrolyte for lithium-ion batteries. → Mixtures with a high ionic liquid (IL) content are non-flammable. → Al corrosion potential is shifted to higher potentials by the addition of IL. → Cycling stability of a Li/LiFePO4 cell at 60 oC is improved by the addition of IL. - Abstract: In this paper we report the results of physical-chemical and electrochemical investigations performed on ternary mixtures of the room temperature ionic liquid (IL) N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14TFSI), propylene carbonate (PC), and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) as electrolyte for lithium-ion batteries. The thermal stability, ionic conductivity, viscosity and electrochemical stability windows of all considered mixtures were investigated and compared with those of electrolytes based on the pure PYR14TFSI and PC. The mixtures were also used as electrolyte in combination with LiFePO4-based electrodes. The specific capacity and cycling stability of these systems were investigated at different C-rates, both at room temperature and 60 oC.

  19. Liquid-liquid extraction of cadmium(II) by TIOACl (tri-iso-octyl ammonium chloride) ionic liquid and its application to a TIOACl impregnated carbon nanotubes system

    International Nuclear Information System (INIS)

    The extraction of cadmium(II) by the ionic liquid (R3NH+Cl-) (R: tri-iso-octyl) in Exxsol D100 from hydrochloric acid solution has been investigated. The extraction reaction is exothermic. The numerical analysis of metal distribution data suggests the formation of R3NH+CdCl-3 - and (R3NH+)2CdCl42- species in the organic phase. The results obtained for cadmium(II) distribution have been implemented in an impregnated multi-walled carbon nanotubes system. The influence of aqueous solution stirring speed (250-2000 min-1), adsorbent dosage (0.05-0.2 g) and temperature (20 degree centigrade-60 degree centigrade) on cadmium adsorption have been investigated. (Author)

  20. Liquid-liquid extraction of cadmium(II) by TIOACl (tri-iso-octyl ammonium chloride) ionic liquid and its application to a TIOACl impregnated carbon nanotubes system

    Energy Technology Data Exchange (ETDEWEB)

    Alguacil, F. J.; Garcia-Diaz, I.; Lopez, F. A.; Rodriguez, O.

    2015-07-01

    The extraction of cadmium(II) by the ionic liquid (R{sub 3}NH{sup +}Cl{sup -}) (R: tri-iso-octyl) in Exxsol D100 from hydrochloric acid solution has been investigated. The extraction reaction is exothermic. The numerical analysis of metal distribution data suggests the formation of R{sub 3}NH{sup +}CdCl{sup -}{sub 3} - and (R{sub 3}NH{sup +}){sub 2}CdCl{sub 4}{sup 2}- species in the organic phase. The results obtained for cadmium(II) distribution have been implemented in an impregnated multi-walled carbon nanotubes system. The influence of aqueous solution stirring speed (250-2000 min{sup -}1), adsorbent dosage (0.05-0.2 g) and temperature (20 degree centigrade-60 degree centigrade) on cadmium adsorption have been investigated. (Author)

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    implemented, leading to an entirely predictive method for densities of mixed compressed ionic liquids. Quantitative agreement with experimental data is obtained over wide ranges of conditions. Previously, the method has been applied to solubilities of sparingly soluble gases in ionic liquids and in organic......A corresponding-states form of the generalized van der Waals equation, previously developed for mixtures of an ionic liquid and a supercritical solute, is here extended to mixtures including an ionic liquid and a solvent (water or organic). Group contributions to characteristic parameters are...... solvents. Here we show results for heavier and more-than-sparingly solutes such as carbon dioxide and propane in ionic liquids....

  2. Electrochemical aspects of ionic liquids

    CERN Document Server

    Ohno, Hiroyuki

    2011-01-01

    The second edition is based on the original book, which has been revised, updated and expanded in order to cover the latest information on this rapidly growing field. The book begins with a description of general and electrochemical properties of ionic liquids and continues with a discussion of applications in biochemistry, ionic devices, functional design and polymeric ionic liquids. The new edition includes new chapters on Li ion Batteries and Actuators, as well as a revision of existing chapters to include a discussion on purification and the effects of impurities, adsorption of ionic liqui

  3. Electrophoretic deposition of multi-walled carbon nanotubes on porous anodic aluminum oxide using ionic liquid as a dispersing agent

    Science.gov (United States)

    Hekmat, F.; Sohrabi, B.; Rahmanifar, M. S.; Jalali, A.

    2015-06-01

    Multi-wall carbon nanotubes (MW-CNTs) have been arranged in nanochannels of anodic aluminum oxide template (AAO) by electrophoretic deposition (EPD) to make a vertically-aligned carbon nanotube (VA-CNT) based electrode. Well ordered AAO templates were prepared by a two-step anodizing process by applying a constant voltage of 45 V in oxalic acid solution. The stabilized CNTs in a water-soluble room temperature ionic liquid (1-methyl-3-octadecylimidazolium bromide), were deposited in the pores of AAO templates which were conductive by deposition of Ni nanoparticles in the bottom of pores. In order to obtain ideal results, different EPD parameters, such as concentration of MWCNTs and ionic liquid on stability of MWCNT suspensions, deposition time and voltage which are applied in EPD process and also optimal conditions for anodizing of template were investigated. The capacitive performance of prepared electrodes was analyzed by measuring the specific capacitance from cyclic voltammograms and the charge-discharge curves. A maximum value of 50 Fg-1 at the scan rate of 20 mV s-1was achieved for the specific capacitance.

  4. Reversible CO2 Capture by Conjugated Ionic Liquids through Dynamic Covalent Carbon-Oxygen Bonds.

    Science.gov (United States)

    Pan, Mingguang; Cao, Ningning; Lin, Wenjun; Luo, Xiaoyan; Chen, Kaihong; Che, Siying; Li, Haoran; Wang, Congmin

    2016-09-01

    The strong chemisorption of CO2 is always accompanied by a high absorption enthalpy, and traditional methods to reduce the absorption enthalpy lead to decreased CO2 capacities. Through the introduction of a large π-conjugated structure into the anion, a dual-tuning approach for the improvement of CO2 capture by anion-functionalized ionic liquids (ILs) resulted in a high capacity of up to 0.96 molCO2  mol-1IL and excellent reversibility. The increased capacity and improved desorption were supported by quantum chemical calculations, spectroscopic investigations, and thermogravimetric analysis. The increased capacity may be a result of the strengthened dynamic covalent bonds in these π-electron-conjugated structures through anion aggregation upon the uptake of CO2 , and the improved desorption originates from the charge dispersion of interaction sites through the large π-electron delocalization. These results provide important insights into effective strategies for CO2 capture. PMID:27458723

  5. (Liquid + liquid) equilibria of perfluorocarbons with fluorinated ionic liquids

    International Nuclear Information System (INIS)

    Highlights: • (Liquid + liquid) equilibria perfluorocarbons and fluorinated ionic liquids. • Non-Random Two Liquid model was successfully applied. • Thermodynamic functions that describe the solvation process were calculated. -- Abstract: In order to evaluate the feasibility of partially replace perfluorocarbons (PFCs) with fluorinated ionic liquids (FILs) in PFCs-in-water emulsions, usually used for biomedical purposes, herein the (liquid + liquid) phase equilibria of FILs containing fluorinated chains longer than four carbons with PFCs were carried out in a wide range of temperatures. With this goal in mind, two PFCs (perfluorooctane and perfluorodecalin) were selected and the (liquid + liquid) equilibria of the binary mixtures of these PFCs and FILs were studied at atmospheric pressure in a temperature range from T (293.15 to 343.15) K. For these studies, FILs containing ammonium, pyridinium and imidazolium cations and different anions with fluorocarbon alkyl chains between 4 and 8 were included. Additionally, Non-Random Two Liquid (NRTL) thermodynamic model was successfully applied to correlate the behaviour of the PFCs + FILs binary mixtures. Moreover, thermodynamic functions that describe the solvation process were calculated from the experimental data

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

    Science.gov (United States)

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

    2015-06-22

    Several ionic liquids (ILs) comprising [B(hfip)4 ](-) [hfip=OCH(CF3 )2 ] or [Al(hfip)4 ](-) anions and imidazolium or ammonium cations were prepared and mixed with up to 270 mol % of dimethyl carbonate (DMC). The viscosities, conductivities, and self-diffusion constants of these mixtures and, where possible, of the neat ILs were measured and compared with common [NTf2 ](-) based ILs and their mixtures with DMC. A tremendous decrease of the viscosities and a likewise increase of the conductivities and diffusion constants can be achieved for all classes of ILs. However, the order of the conductivities is partially reversed in the diffusion data. This is probably due to the low dielectric constant of DMC and the, thus, favored ion pairing, as evidenced, for example, by the calculated ionicities. Altogether, our data show that the chemically robust, but high-melting and more viscous [B(hfip)4 ](-) ILs might be candidates for electrolytes when mixed with suitable molecular solvents. PMID:25877038

  7. Ionic Liquid Epoxy Resin Monomers

    Science.gov (United States)

    Paley, Mark S. (Inventor)

    2013-01-01

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

  8. Electrochemical Depositions in Ionic Liquids

    OpenAIRE

    De Vreese, Peter

    2013-01-01

    In this PhD thesis, several aspects of the electrodeposition of metals and alloys in ionic liquids were investigated. First, the deposition of brass from choline acetate was studied. Secondly, the electrodeposition of pure molybdenum from ionic liquids based on phosphonium chloride and zinc chloride was treated. In each case, the influence of water, either as a main constituent of the electrolyte or an impurity, was investigated. When comparing electrochemical processes such as electrodeposit...

  9. Ionic liquids within polymer matrices

    Czech Academy of Sciences Publication Activity Database

    Matějka, Libor; Donato, Ricardo Keitel; Schrekker, H. S.

    Gargnano, Lago di Garda : European Polymer Federation, 2013. s. 10. [EUPOC 2013 on Polymers & Ionic Liquids. 01.09.2013-05.09.2013, Gargnano, Lago di Garda] R&D Projects: GA ČR GAP108/12/1459 Grant ostatní: AV ČR(CZ) M200501203 Institutional support: RVO:61389013 Keywords : ionic liquids * nanocomposite * epoxide Subject RIV: CD - Macromolecular Chemistry

  10. Direct Electrochemistry and Electrocatalysis of Myoglobin with CoMoO4 Nanorods Modified Carbon Ionic Liquid Electrode

    International Nuclear Information System (INIS)

    By using ionic liquid 1-hexylpyridinium hexafluorophosphate (HPPF6) based carbon ionic liquid electrode (CILE) as the substrate electrode, a CoMoO4 nanorods and myoglobin (Mb) composite was casted on the surface of CILE with chitosan (CTS) as the film forming material to obtain the modified electrode (CTS/CoMoO4-Mb/CILE). Spectroscopic results indicated that Mb retained its native structures without any conformational changes after mixed with CoMoO4 nanorods and CTS. Electrochemical behaviors of Mb on the electrode were carefully investigated by cyclic voltammetry with a pair of well-defined redox peaks from the heme Fe(III)/Fe(II) redox center of Mb appeared, which indicated that direct electron transfer between Mb and CILE was realized. Electrochemical parameters such as the electron transfer number (n), charge transfer coefficient (α) and electron transfer rate constant (ks) were estimated by cyclic voltammetry with the results as 1.09, 0.53 and 1.16 s-1, respectively. The Mb modified electrode showed good electrocatalytic ability toward the reduction of trichloroacetic acid in the concentration range from 0.1 to 32.0 mmol L-1 with the detection limit as 0.036 mmol L-1 (3σ), and the reduction of H2O2 in the concentration range from 0.12 to 397.0 μmol L-1 with the detection limit as 0.0426 μmol L-1 (3σ)

  11. A novel nonenzymatic hydrogen peroxide sensor based on silver nanoparticles and ionic liquid functionalized multiwalled carbon nanotube composite modified electrode

    International Nuclear Information System (INIS)

    Highlights: • A novel nonenzymatic H2O2 sensor was constructed on AgNPs/MWCNTs-IL modified GCE. • Ionic liquid functionalized carbon nanotube was used as matrices for deposition of AgNPs effectively. • AgNPs were uniformly and less agglomerate formed on the MWCNTs-IL film. • AgNPs/MWCNTs-IL/GCE displayed good electrocatalytic activity to the reduction of H2O2 and applied to real samples. • The electrocatalytic mechanism of the constructed sensor was proposed. -- Abstract: A novel hydrogen peroxide (H2O2) sensor was fabricated by electrodepositing Ag nanoparticles (NPs) on a glassy carbon electrode (GCE) modified with ionic liquid functionalized multiwalled carbon nanotube (MWCNTs-IL) composites. The AgNPs/MWCNTs-IL composite was characterized by different methods including scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The constructed electrode exhibited good catalytic activity toward the reduction of H2O2, and obtained a linear response to logarithm of the H2O2 concentrations ranging from 1.2 × 10−8 to 4.8 × 10−6 M with a limit of detection (LOD) of 3.9 × 10−9 M. Moreover, it can be applied to real samples analysis. The excellent performance of hydrogen peroxide sensor were ascribed to the MWCNTs-IL composites being used as effective load matrix for the deposition of AgNPs and the synergistic amplification effect of the two kinds of nanomaterials – AgNPs and MWCNTs. Therefore, the catalytic mechanism of the constructed sensor was proposed. AgNPs dispersed on MWCNTs-IL were used as the catalyst for the H2O2 into O2, and the generated oxygen transported the electrode surrounding where it was detected by reduction on the electrode

  12. Structure and morphology controllable synthesis of Ag/carbon hybrid with ionic liquid as soft-template and their catalytic properties

    International Nuclear Information System (INIS)

    Ag/carbon hybrids were fabricated by the redox of glucose and silver nitrate (AgNO3) in the presence of imidazolium ionic liquid ([C14mim]BF4) under hydrothermal condition. Monodisperse carbon hollow sub-microspheres encapsulating Ag nanoparticles and Ag/carbon cables were selectively prepared by varying the concentration of ionic liquid. Other reaction parameters, such as reaction temperature, reaction time and the mole ratio of silver nitrate to glucose, play important roles in controlling the structures of the products. The products were characterized by XRD, TEM (HRTEM), SEM, energy-dispersive X-ray spectroscopy (EDX), FTIR spectroscopy and a Raman spectrometer. The possible formation mechanism was proposed. The catalytic property of the hybrid in the oxidation of 1-butanol by H2O2 was also investigated. - Graphical abstract: Monodisperse carbon hollow nanospheres encapsulating Ag nanoparticles and Ag/carbon nanocables were selectively prepared with ionic liquids as the soft-template. The controllable synthesis of Ag/C nano-hybrids was realized by varying the concentration of ionic liquids, reaction temperature, reaction time and the mole ratio of silver nitrate to glucose. The catalysis of Ag/C nano-hybrid in the oxidation of 1-butanol by H2O2 was also investigated

  13. Simultaneous Determination of Hydroquinone, Catechol and Resorcinol at Graphene Doped Carbon Ionic Liquid Electrode

    Directory of Open Access Journals (Sweden)

    Li Ma

    2012-01-01

    Full Text Available A new composite electrode has been prepared with doping graphene into the paste consisting graphite and ionic liquid, n-octyl-pyridinum hexafluorophosphate (OPFP. This electrode shows an excellent electrochemical activity for the redox of hydroquinone (HQ, catechol (CC, and resorcinol (RS. In comparison with bare paste electrode, the redox peaks of three isomers of dihydroxybenzene can be obviously, simultaneously observed at graphene doping paste electrode. Under the optimized condition, the simultaneous determination of HQ, CC, and RS in their ternary mixture can be carried out with a differential pulse voltammetric technique. The peak currents are linear to the concentration of HQ, CC, and RS in the range form 1×10−5 to 4×10−4, 1×10−5 to 3×10−4, and 1×10−6 to 1.7×10−4 mol L−1, respectively. The limits of detection are 1.8×10−6 mol L−1 for HQ, 7.4×10−7 mol L−1 for CC, and 3.6×10−7 M for RS, respectively.

  14. Understanding the effect of side groups in ionic liquids on carbon-capture properties: a combined experimental and theoretical effort

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Fangyong [Univ. of California, Berkeley, CA (United States). Dept. of Chemical and Biomolecular Engingeering; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Lartey, Michael [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Damodaran, Krishnan [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Univ. of Pittsburgh, PA (United States). Dept. of Chemistry; Albenze, Erik [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); URS Corporation, South Park, PA (United States); Thompson, Robert L. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); URS Corporation, South Park, PA (United States); Kim, Jihan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Science Div.; Harancyzk, Maciel [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Computational Research Div.; Nulwala, Hunaid B. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Carnegie Mellon Univ., Pittsburgh, PA (United States); Luebke, David R. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Smit, Berend [Univ. of California, Berkeley, CA (United States). Dept. of Chemical and Biomolecular Engingeering; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division

    2013-01-01

    Ionic liquids are an emerging class of materials with applications in a variety of fields. Steady progress has been made in the creation of ionic liquids tailored to specific applications. However, the understanding of the underlying structure–property relationships has been slower to develop. As a step in the effort to alleviate this deficiency, the influence of side groups on ionic liquid properties has been studied through an integrated approach utilizing synthesis, experimental determination of properties, and simulation techniques. To achieve this goal, a classical force field in the framework of OPLS/Amber force fields has been developed to predict ionic liquid properties accurately. Cu(I)-catalyzed click chemistry was employed to synthesize triazolium-based ionic liquids with diverse side groups. Values of densities were predicted within 3% of experimental values, whereas self-diffusion coefficients were underestimated by about an order of magnitude though the trends were in excellent agreement, the activation energy calculated in simulation correlates well with experimental values. The predicted Henry coefficient for CO{sub 2} solubility reproduced the experimentally observed trends. This study highlights the importance of integrating experimental and computational approaches in property prediction and materials development, which is not only useful in the development of ionic liquids for CO{sub 2} capture but has application in many technological fields.

  15. Ultrafast vibrational spectroscopy (2D-IR) of CO{sub 2} in ionic liquids: Carbon capture from carbon dioxide’s point of view

    Energy Technology Data Exchange (ETDEWEB)

    Brinzer, Thomas; Berquist, Eric J.; Ren, Zhe; Dutta, Samrat; Johnson, Clinton A.; Krisher, Cullen S.; Lambrecht, Daniel S.; Garrett-Roe, Sean, E-mail: sgr@pitt.edu [Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260 (United States)

    2015-06-07

    The CO{sub 2}ν{sub 3} asymmetric stretching mode is established as a vibrational chromophore for ultrafast two-dimensional infrared (2D-IR) spectroscopic studies of local structure and dynamics in ionic liquids, which are of interest for carbon capture applications. CO{sub 2} is dissolved in a series of 1-butyl-3-methylimidazolium-based ionic liquids ([C{sub 4}C{sub 1}im][X], where [X]{sup −} is the anion from the series hexafluorophosphate (PF{sub 6}{sup −}), tetrafluoroborate (BF{sub 4}{sup −}), bis-(trifluoromethyl)sulfonylimide (Tf{sub 2}N{sup −}), triflate (TfO{sup −}), trifluoroacetate (TFA{sup −}), dicyanamide (DCA{sup −}), and thiocyanate (SCN{sup −})). In the ionic liquids studied, the ν{sub 3} center frequency is sensitive to the local solvation environment and reports on the timescales for local structural relaxation. Density functional theory calculations predict charge transfer from the anion to the CO{sub 2} and from CO{sub 2} to the cation. The charge transfer drives geometrical distortion of CO{sub 2}, which in turn changes the ν{sub 3} frequency. The observed structural relaxation timescales vary by up to an order of magnitude between ionic liquids. Shoulders in the 2D-IR spectra arise from anharmonic coupling of the ν{sub 2} and ν{sub 3} normal modes of CO{sub 2}. Thermal fluctuations in the ν{sub 2} population stochastically modulate the ν{sub 3} frequency and generate dynamic cross-peaks. These timescales are attributed to the breakup of ion cages that create a well-defined local environment for CO{sub 2}. The results suggest that the picosecond dynamics of CO{sub 2} are gated by local diffusion of anions and cations.

  16. Ultrafast vibrational spectroscopy (2D-IR) of CO2 in ionic liquids: Carbon capture from carbon dioxide's point of view

    Science.gov (United States)

    Brinzer, Thomas; Berquist, Eric J.; Ren, Zhe; Dutta, Samrat; Johnson, Clinton A.; Krisher, Cullen S.; Lambrecht, Daniel S.; Garrett-Roe, Sean

    2015-06-01

    The CO2ν3 asymmetric stretching mode is established as a vibrational chromophore for ultrafast two-dimensional infrared (2D-IR) spectroscopic studies of local structure and dynamics in ionic liquids, which are of interest for carbon capture applications. CO2 is dissolved in a series of 1-butyl-3-methylimidazolium-based ionic liquids ([C4C1im][X], where [X]- is the anion from the series hexafluorophosphate (PF 6- ), tetrafluoroborate (BF 4- ), bis-(trifluoromethyl)sulfonylimide (Tf2N-), triflate (TfO-), trifluoroacetate (TFA-), dicyanamide (DCA-), and thiocyanate (SCN-)). In the ionic liquids studied, the ν3 center frequency is sensitive to the local solvation environment and reports on the timescales for local structural relaxation. Density functional theory calculations predict charge transfer from the anion to the CO2 and from CO2 to the cation. The charge transfer drives geometrical distortion of CO2, which in turn changes the ν3 frequency. The observed structural relaxation timescales vary by up to an order of magnitude between ionic liquids. Shoulders in the 2D-IR spectra arise from anharmonic coupling of the ν2 and ν3 normal modes of CO2. Thermal fluctuations in the ν2 population stochastically modulate the ν3 frequency and generate dynamic cross-peaks. These timescales are attributed to the breakup of ion cages that create a well-defined local environment for CO2. The results suggest that the picosecond dynamics of CO2 are gated by local diffusion of anions and cations.

  17. Ultrafast vibrational spectroscopy (2D-IR) of CO2 in ionic liquids: Carbon capture from carbon dioxide’s point of view

    International Nuclear Information System (INIS)

    The CO2ν3 asymmetric stretching mode is established as a vibrational chromophore for ultrafast two-dimensional infrared (2D-IR) spectroscopic studies of local structure and dynamics in ionic liquids, which are of interest for carbon capture applications. CO2 is dissolved in a series of 1-butyl-3-methylimidazolium-based ionic liquids ([C4C1im][X], where [X]− is the anion from the series hexafluorophosphate (PF6−), tetrafluoroborate (BF4−), bis-(trifluoromethyl)sulfonylimide (Tf2N−), triflate (TfO−), trifluoroacetate (TFA−), dicyanamide (DCA−), and thiocyanate (SCN−)). In the ionic liquids studied, the ν3 center frequency is sensitive to the local solvation environment and reports on the timescales for local structural relaxation. Density functional theory calculations predict charge transfer from the anion to the CO2 and from CO2 to the cation. The charge transfer drives geometrical distortion of CO2, which in turn changes the ν3 frequency. The observed structural relaxation timescales vary by up to an order of magnitude between ionic liquids. Shoulders in the 2D-IR spectra arise from anharmonic coupling of the ν2 and ν3 normal modes of CO2. Thermal fluctuations in the ν2 population stochastically modulate the ν3 frequency and generate dynamic cross-peaks. These timescales are attributed to the breakup of ion cages that create a well-defined local environment for CO2. The results suggest that the picosecond dynamics of CO2 are gated by local diffusion of anions and cations

  18. Fabrication of gallium hexacyanoferrate modified carbon ionic liquid paste electrode for sensitive determination of hydrogen peroxide and glucose

    International Nuclear Information System (INIS)

    Gallium hexacyanoferrate (GaHCFe) and graphite powder were homogeneously dispersed into n-dodecylpyridinium hexafluorophosphate and paraffin to fabricate GaHCFe modified carbon ionic liquid paste electrode (CILPE). Mixture experimental design was employed to optimize the fabrication of GaHCFe modified CILPE (GaHCFe-CILPE). A pair of well-defined redox peaks due to the redox reaction of GaHCFe through one-electron process was observed for the fabricated electrode. The fabricated GaHCFe-CILPE exhibited good electrocatalytic activity towards reduction and oxidation of H2O2. The observed sensitivities for the electrocatalytic oxidation and reduction of H2O2 at the operating potentials of + 0.8 and − 0.2 V were about 13.8 and 18.3 mA M−1, respectively. The detection limit (S/N = 3) for H2O2 was about 1 μM. Additionally, glucose oxidase (GOx) was immobilized on GaHCFe-CILPE using two methodology, entrapment into Nafion matrix and cross-linking with glutaraldehyde and bovine serum albumin, in order to fabricate glucose biosensor. Linear dynamic rage, sensitivity and detection limit for glucose obtained by the biosensor fabricated using cross-linking methodology were 0.1–6 mM, 0.87 mA M−1 and 30 μM, respectively and better than those obtained (0.2–6 mM, 0.12 mA M−1 and 50 μM) for the biosensor fabricated using entrapment methodology. - Highlights: • Gallium hexacyanoferrate modified carbon ionic liquid paste electrode was fabricated. • Mixture experimental design was used to optimize electrode fabrication. • Response trace plot was used to show the effect of electrode materials on response. • The sensor exhibited electrocatalytic activity towards H2O2 reduction and oxidation. • Glucose biosensor was fabricated by immobilization of glucose oxidase on sensor

  19. Lipid processing in ionic liquids

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  20. Surface structured platinum electrodes for the electrochemical reduction of carbon dioxide in imidazolium based ionic liquids.

    Science.gov (United States)

    Hanc-Scherer, Florin A; Montiel, Miguel A; Montiel, Vicente; Herrero, Enrique; Sánchez-Sánchez, Carlos M

    2015-10-01

    The direct CO2 electrochemical reduction on model platinum single crystal electrodes Pt(hkl) is studied in [C2mim(+)][NTf2(-)], a suitable room temperature ionic liquid (RTIL) medium due to its moderate viscosity, high CO2 solubility and conductivity. Single crystal electrodes represent the most convenient type of surface structured electrodes for studying the impact of RTIL ion adsorption on relevant electrocatalytic reactions, such as surface sensitive electrochemical CO2 reduction. We propose here based on cyclic voltammetry and in situ electrolysis measurements, for the first time, the formation of a stable adduct [C2mimH-CO2(-)] by a radical-radical coupling after the simultaneous reduction of CO2 and [C2mim(+)]. It means between the CO2 radical anion and the radical formed from the reduction of the cation [C2mim(+)] before forming the corresponding electrogenerated carbene. This is confirmed by the voltammetric study of a model imidazolium-2-carboxylate compound formed following the carbene pathway. The formation of that stable adduct [C2mimH-CO2(-)] blocks CO2 reduction after a single electron transfer and inhibits CO2 and imidazolium dimerization reactions. However, the electrochemical reduction of CO2 under those conditions provokes the electrochemical cathodic degradation of the imidazolium based RTIL. This important limitation in CO2 recycling by direct electrochemical reduction is overcome by adding a strong acid, [H(+)][NTf2(-)], into solution. Then, protons become preferentially adsorbed on the electrode surface by displacing the imidazolium cations and inhibiting their electrochemical reduction. This fact allows the surface sensitive electro-synthesis of HCOOH from CO2 reduction in [C2mim(+)][NTf2(-)], with Pt(110) being the most active electrode studied. PMID:26307480

  1. The preparation of carbon dots/ionic liquids-based electrolytes and their applications in quasi-solid-state dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Highlights: ► A facile means to generate carbon dots/ionic liquids (ILs) – were demonstrated. ► The carbon dots/ILs blend were used for fabricating quasi-solid-state DSSCs. ► Cells exhibited good stability in room temperature without any further sealing. -- Abstract: A facile means to generate carbon dots/ionic liquids (ILs) blend using ionic liquid-assisted electrochemical exfoliation was demonstrated. Two kinds of ILs, 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) and 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]), were used in this work. Transmission electron microscopy and UV–vis spectrum were employed to characterize the formed carbon dots/ILs. The carbon dots/ILs were used for fabricating quasi-solid-state dye-sensitized solar cells (DSSCs), where 1-butyl-3-methylimidazolium iodide and LiI/I2 were added to enhance the performance of DSSCs. Effects of the varied contents of components in the complex on the performance of DCCSs have been studied in detail at ambient temperature. The electrochemical impedance spectroscopy showed that the introduction of carbon dots into ionic liquids can enhance the electrical properties by facilitating charge transfer processes of the electrolytes. The overall energy-conversion efficiency (η) was 2.71% and 2.41% for carbon dots/[bmim][PF6] and carbon dots/[bmim][BF4] based blend electrolytes, respectively. A 82% enhancement in η was obtained by introduction of carbon dots into [bmim][PF6] comparing with pure [bmim][PF6] (η = 1.49%). In addition, the cells exhibited good stability under continuous illumination in room temperature without any further sealing

  2. Sensitive voltammetric determination of chloramphenicol by using single-wall carbon nanotube-gold nanoparticle-ionic liquid composite film modified glassy carbon electrodes

    International Nuclear Information System (INIS)

    A novel composite film modified glassy carbon electrode has been fabricated and characterized by scanning electron microscope (SEM) and voltammetry. The composite film comprises of single-wall carbon nanotube (SWNT), gold nanoparticle (GNP) and ionic liquid (i.e. 1-octyl-3-methylimidazolium hexafluorophosphate), thus has the characteristics of them. The resulting electrode shows good stability, high accumulation efficiency and strong promotion to electron transfer. On it, chloramphenicol can produce a sensitive cathodic peak at -0.66 V (versus SCE) in pH 7.0 phosphate buffer solutions. Parameters influencing the voltammetric response of chloramphenicol are optimized, which include the composition of the film and the operation conditions. Under the optimized conditions, the peak current is linear to chloramphenicol concentration in the range of 1.0 x 10-8-6.0 x 10-6 M, and the detection limit is estimated to be 5.0 x 10-9 M after an accumulation for 150 s on open circuit. The electrode is applied to the determination of chloramphenicol in milk samples, and the recoveries for the standards added are 97.0% and 100.3%. In addition, the electrochemical reaction of chloramphenicol and the effect of single-wall carbon nanotube, gold nanoparticle and ionic liquid are discussed

  3. Mixture of ionic liquid and carbon nanotubes: comparative studies of the structural characteristics and dispersion of the aggregated non-bundled and bundled carbon nanotubes.

    Science.gov (United States)

    Mohammadi, Morteza; Foroutan, Masumeh

    2013-02-21

    In this work, the two mixtures of ionic liquid 1-n-propyl-4-amino-1,2,4-triazolium bromide and each type of the aggregated single-walled carbon nanotubes (SWCNTs), i.e. bundled SWCNTs and non-bundled, were investigated using molecular dynamics (MD) simulations. The structural characteristics of a SWCNT in the ionic liquid (IL) were examined by analyzing the radial distribution functions and the results show that the nearest IL cations to the SWCNT surface can approach it from three different positions. Also, the possibility of the dispersion of the bundled SWCNTs containing three and seven carbon nanotubes was investigated. The obtained results showed that under the investigated conditions, the IL cannot disperse the bundled SWCNTs, but it can disperse six and seven aggregated non-bundled ones. Moreover, we investigated the underlying dispersion mechanism of the aggregated SWCNTs in the IL, using MD simulations. The self diffusion coefficients and transport numbers of the cations and anions were computed in the systems containing pure IL, the mixtures of IL and one, six and seven non-bundled SWCNTs and the systems containing IL and bundled SWCNTs with three and seven carbon nanotubes. The obtained results showed that the diffusion coefficients and the transport numbers of the cations are more than anions in all mentioned systems. PMID:23318467

  4. The direct electrochemistry of glucose oxidase based on the synergic effect of amino acid ionic liquid and carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Amino acid ionic liquids(AAILs) have attracted much attention due to their special chemical and physical properties,especially their outstanding biocompatibility and truly green aspect.In this work,a novel electrochemical biosensing platform based on AAILs/carbon nanotubes(CNTs) composite was fabricated.AAILs were used as a novel solvent for glucose oxidase(GOD) and the GOD-AAILs/CNTs/GC electrode was conveniently prepared by immersing the carbon nanotubes(CNTs) modified glassy carbon(GC) electrode into AAILs containing GOD.The direct electrochemistry of GOD on the GOD-AAILs/CNTs/GC electrode has been investigated and a pair of reversible peaks was obtained by cyclic voltammetry.The immobilized glucose oxidase could retain bioactivity and catalyze the reduction of dissolved oxygen.Due to the synergic effect of AAILs and CNTs,the GOD-AAILs/CNTs/GC electrode shows excellent electrocatalytic activity towards glucose with a linear range from 0.05 to 0.8 mM and a detection limit of 5.5 μM(S/N = 3).Furthermore,the biosensor exhibits good stability and ability to exclude the interference of commonly coexisting uric and ascorbic acid.Therefore,AAILs/CNTs composite can be a good candidate biocompatible material for the direct electrochemistry of the redox-active enzyme and the construction of third-generation enzyme sensors.

  5. The direct electrochemistry of glucose oxidase based on the synergic effect of amino acid ionic liquid and carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    WANG MengDong; DENG ChunYan; NIE Zhou; XU XiaHong; YAO ShouZhuo

    2009-01-01

    Amino acid ionic liquids (AAILs) have attracted much attention due to their special chemical and physical properties,especially their outstanding biocompatibility and truly green aspect.In this work,a novel electrochemical biosensing platform based on AAILs/carbon nanotubes (CNTs) composite was fabricated.AAILs were used as a novel solvent for glucose oxidase (GOD) and the GOD-AAILs/CNTs/GC electrode was conveniently prepared by immersing the carbon nanotubes (CNTs) modified glassy carbon (GC) electrode into AAILs containing GOD.The direct electrochemistry of GOD on the GOD-AAILs/CNTs/GC electrode has been investigated and a pair of reversible peaks was obtained by cyclic voltammetry.The immobilized glucose oxidase could retain bioactivity and catalyze the reduction of dissolved oxygen.Due to the synergic effect of AAILs and CNTs,the GOD-AAILs/CNTs/GC electrode shows excellent electrocatalytic activity towards glucose with a linear range from 0.05 to 0.8 mM and a detection limit of 5.5 μM (S/N=3).Furthermore,the biosensor exhibits good stability and ability to exclude the interference of commonly coexisting uric and ascorbic acid.Therefore,AAILs/CNTs composite can be a good candidate biocompatible material for the direct electrochemistry of the redox-active enzyme and the construction of third-generation enzyme sensors.

  6. Fabrication of electrochemical theophylline sensor based on manganese oxide nanoparticles/ionic liquid/chitosan nanocomposite modified glassy carbon electrode

    International Nuclear Information System (INIS)

    In this study, the preparation of a glassy carbon (GC) electrode modified with chitosan/NH2-ionic liquid/manganese oxide nanoparticles (Chit/NH2-IL/MnOx) was described for electrocatalytic detection of theophylline (TP). First, chitosan hydrogel (Chit) was electrodeposited on the GC electrode surface at a constant potential (−1.5 V) in acidic solution. Then, the previously synthesized amine-terminated 1-(3-Aminopropyl)-3-methylimidazolium bromide ionic liquid (NH2-IL) was covalently attached to the modified electrode via glutaraldehyde (GA) as linking agent. Finally, manganese oxide (MnOx) nanoparticles were electrodeposited onto the Chit/NH2-IL film by potential cycling between −1.0 and 1.7 V in Mn(CH3COO)2·4H2O neutral aqueous solution. Electrochemical behavior of the modified electrode was evaluated by cyclic voltammetry (CV) technique. The charge transfer coefficient (α) and electron transfer rate constant (ks) for MnOOH/MnO2 redox couple were calculated to be 0.35 and 1.62 s−1, respectively. The resulting system brings new capabilities for electrochemical sensing through combining the advantages of IL and MnOx nanoparticles. The differential pulse voltammetric (DPV) results indicated the high ability of GC/Chit/NH2-IL/MnOx modified electrode to catalyze the oxidation of TP. DPV determination of TP in acetate buffer solution (pH 5) gave linear responses over the concentration range up to 120 μM with the detection limit of 50 nM and sensitivity of 804 nA μM−1. Furthermore, the applicability of the sensor for TP analysis in pharmaceutical samples has been successfully demonstrated

  7. Poly(methylene blue) functionalized graphene modified carbon ionic liquid electrode for the electrochemical detection of dopamine

    Energy Technology Data Exchange (ETDEWEB)

    Sun Wei, E-mail: swyy26@hotmail.com [College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China); College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Wang Yuhua; Zhang Yuanyuan; Ju Xiaomei; Li Guangjiu [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Sun Zhenfan [College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China)

    2012-11-02

    Highlights: Black-Right-Pointing-Pointer Poly(methylene blue) functionalized graphene was electrodeposited on the electrode. Black-Right-Pointing-Pointer The fabricated electrode showed better electrochemical performances. Black-Right-Pointing-Pointer Dopamine was sensitive detected by the modified electrode. - Abstract: An ionic liquid 1-butylpyridinium hexafluorophosphate based carbon ionic liquid electrode (CILE) was used as the substrate electrode and a poly(methylene blue) (PMB) functionalized graphene (GR) composite film was co-electrodeposited on CILE surface by cyclic voltammetry. The PMB-GR/CILE exhibited better electrochemical performances with higher conductivity and lower electron transfer resistance. Electrochemical behavior of dopamine (DA) was further investigated by cyclic voltammetry and a pair of well-defined redox peaks appeared with the peak-to-peak separation ({Delta}E{sub p}) as 0.058 V in 0.1 mol L{sup -1} pH 6.0 phosphate buffer solution, which proved a fast quasi-reversible electron transfer process on the modified electrode. Electrochemical parameters of DA on PMB-GR/CILE were calculated with the electron transfer number as 1.83, the charge transfer coefficients as 0.70, the apparent heterogeneous electron transfer rate constant as 1.72 s{sup -1} and the diffusional coefficient (D) as 3.45 Multiplication-Sign 10{sup -4} cm{sup 2} s{sup -1}, respectively. Under the optimal conditions with differential pulse voltammetric measurement, the linear relationship between the oxidation peak current of DA and its concentration was obtained in the range from 0.02 to 800.0 {mu}mol L{sup -1} with the detection limit as 5.6 nmol L{sup -1} (3{sigma}). The coexisting substances exhibited no interference and PMB-GR/CILE was applied to the detection of DA injection samples and human urine samples with satisfactory results.

  8. Poly(methylene blue) functionalized graphene modified carbon ionic liquid electrode for the electrochemical detection of dopamine

    International Nuclear Information System (INIS)

    Highlights: ► Poly(methylene blue) functionalized graphene was electrodeposited on the electrode. ► The fabricated electrode showed better electrochemical performances. ► Dopamine was sensitive detected by the modified electrode. - Abstract: An ionic liquid 1-butylpyridinium hexafluorophosphate based carbon ionic liquid electrode (CILE) was used as the substrate electrode and a poly(methylene blue) (PMB) functionalized graphene (GR) composite film was co-electrodeposited on CILE surface by cyclic voltammetry. The PMB–GR/CILE exhibited better electrochemical performances with higher conductivity and lower electron transfer resistance. Electrochemical behavior of dopamine (DA) was further investigated by cyclic voltammetry and a pair of well-defined redox peaks appeared with the peak-to-peak separation (ΔEp) as 0.058 V in 0.1 mol L−1 pH 6.0 phosphate buffer solution, which proved a fast quasi-reversible electron transfer process on the modified electrode. Electrochemical parameters of DA on PMB–GR/CILE were calculated with the electron transfer number as 1.83, the charge transfer coefficients as 0.70, the apparent heterogeneous electron transfer rate constant as 1.72 s−1 and the diffusional coefficient (D) as 3.45 × 10−4 cm2 s−1, respectively. Under the optimal conditions with differential pulse voltammetric measurement, the linear relationship between the oxidation peak current of DA and its concentration was obtained in the range from 0.02 to 800.0 μmol L−1 with the detection limit as 5.6 nmol L−1 (3σ). The coexisting substances exhibited no interference and PMB–GR/CILE was applied to the detection of DA injection samples and human urine samples with satisfactory results.

  9. Structure and morphology controllable synthesis of Ag/carbon hybrid with ionic liquid as soft-template and their catalytic properties

    Science.gov (United States)

    Wu, Shu Ying; Ding, Yun Sheng; Zhang, Xiao Min; Tang, Hai Ou; Chen, Long; Li, Bo Xuan

    2008-09-01

    Ag/carbon hybrids were fabricated by the redox of glucose and silver nitrate (AgNO 3) in the presence of imidazolium ionic liquid ([C 14mim]BF 4) under hydrothermal condition. Monodisperse carbon hollow sub-microspheres encapsulating Ag nanoparticles and Ag/carbon cables were selectively prepared by varying the concentration of ionic liquid. Other reaction parameters, such as reaction temperature, reaction time and the mole ratio of silver nitrate to glucose, play important roles in controlling the structures of the products. The products were characterized by XRD, TEM (HRTEM), SEM, energy-dispersive X-ray spectroscopy (EDX), FTIR spectroscopy and a Raman spectrometer. The possible formation mechanism was proposed. The catalytic property of the hybrid in the oxidation of 1-butanol by H 2O 2 was also investigated.

  10. A novel and simple electrochemical sensor for electrocatalytic reduction of nitrite and oxidation of phenylhydrazine based on poly (o-anisidine) film using ionic liquid carbon paste electrode

    International Nuclear Information System (INIS)

    In this study, nitrite electroreduction and phenylhydrazine electrooxidation were investigated on poly(o-anisidine) formed by cyclic voltammetry at the surface of ionic liquid carbon paste electrode. The films were characterized by cyclic voltammetry and scanning electron microscopy (SEM) and were contrasted with poly(o-anisidine) prepared under identical conditions in the absence of ionic liquid in carbon paste electrode. This carbon paste modified electrode exhibits a good electrocatalytic capability (via an EC’ mechanism) for both electrooxidation and electroreduction of some important molecules. The obtained results showed that the catalytic oxidation peak currents of phenylhydrazine and catalytic reduction peak currents of nitrite at the surface of this simple (unfunctionalized) polymeric electrode were linearly dependent on their concentrations. Electrode was successfully applied for determination of nitrite and phenylhydrazine in real samples.

  11. Liquid-liquid extraction of cadmium(II by TIOACl (tri-iso-octylammonium chloride ionic liquid and its application to a TIOACl impregnated carbon nanotubes system

    Directory of Open Access Journals (Sweden)

    Alguacil, Francisco J.

    2015-09-01

    Full Text Available The extraction of cadmium(II by the ionic liquid (R3NH+Cl- (R: tri-iso-octyl in Exxsol D100 from hydrochloric acid solution has been investigated. The extraction reaction is exothermic. The numerical analysis of metal distribution data suggests the formation of R3NH+CdCl3− and (R3NH+2CdCl42− species in the organic phase. The results obtained for cadmium(II distribution have been implemented in an impregnated multi-walled carbon nanotubes system. The influence of aqueous solution stirring speed (250–2000 min−1, adsorbent dosage (0.05–0.2 g and temperature (20 °C–60 °C on cadmium adsorption have been investigated.Se ha estudiado la extracción de cadmio(II, de disoluciones en medio HCl, por el líquido iónico (R3NH+Cl- (R: tri-iso-octyl disuelto en Exxsol D100. La reacción de extracción tiene un carácter exotérmico. El análisis numérico de la distribución del metal sugiere la formación de las especies R3NH+CdCl3− y (R3NH+2CdCl42− en la fase orgánica. Estos resultados se han implementado en un sistema que utiliza nanotubos de carbono de pared múltiple impregnados con este líquido iónico. Se han investigado diversas variables experimentales: velocidad de agitación de la disolución acuosa (250–2000 min−1, adición del adsorbente (0,05–0,2 g y temperatura (20–60 °C.

  12. Gaseous Hydrocarbon Separations Using Functionalized Ionic Liquids

    OpenAIRE

    Moura Leila; Santini Catherine C.; Costa Gomes Margarida F.

    2016-01-01

    The functionalization of the side chains on the cation or the anion of an ionic liquid is a common approach to tailor its properties for different processes including the separation of gases. In this paper, we present the current state of the art concerning the usage of ionic liquids for hydrocarbon separations. We also show how the functionalization of ionic liquids or the appropriate anion/cation combinations can contribute to the increase of the performance of the ionic liquids for the sep...

  13. Fabrication of gallium hexacyanoferrate modified carbon ionic liquid paste electrode for sensitive determination of hydrogen peroxide and glucose

    Energy Technology Data Exchange (ETDEWEB)

    Haghighi, Behzad, E-mail: haghighi@iasbs.ac.ir; Khosravi, Mehdi; Barati, Ali

    2014-07-01

    Gallium hexacyanoferrate (GaHCFe) and graphite powder were homogeneously dispersed into n-dodecylpyridinium hexafluorophosphate and paraffin to fabricate GaHCFe modified carbon ionic liquid paste electrode (CILPE). Mixture experimental design was employed to optimize the fabrication of GaHCFe modified CILPE (GaHCFe-CILPE). A pair of well-defined redox peaks due to the redox reaction of GaHCFe through one-electron process was observed for the fabricated electrode. The fabricated GaHCFe-CILPE exhibited good electrocatalytic activity towards reduction and oxidation of H{sub 2}O{sub 2}. The observed sensitivities for the electrocatalytic oxidation and reduction of H{sub 2}O{sub 2} at the operating potentials of + 0.8 and − 0.2 V were about 13.8 and 18.3 mA M{sup −1}, respectively. The detection limit (S/N = 3) for H{sub 2}O{sub 2} was about 1 μM. Additionally, glucose oxidase (GOx) was immobilized on GaHCFe-CILPE using two methodology, entrapment into Nafion matrix and cross-linking with glutaraldehyde and bovine serum albumin, in order to fabricate glucose biosensor. Linear dynamic rage, sensitivity and detection limit for glucose obtained by the biosensor fabricated using cross-linking methodology were 0.1–6 mM, 0.87 mA M{sup −1} and 30 μM, respectively and better than those obtained (0.2–6 mM, 0.12 mA M{sup −1} and 50 μM) for the biosensor fabricated using entrapment methodology. - Highlights: • Gallium hexacyanoferrate modified carbon ionic liquid paste electrode was fabricated. • Mixture experimental design was used to optimize electrode fabrication. • Response trace plot was used to show the effect of electrode materials on response. • The sensor exhibited electrocatalytic activity towards H{sub 2}O{sub 2} reduction and oxidation. • Glucose biosensor was fabricated by immobilization of glucose oxidase on sensor.

  14. Hydrophobic ionic liquid immoblizing cholesterol oxidase on the electrodeposited Prussian blue on glassy carbon electrode for detection of cholesterol

    International Nuclear Information System (INIS)

    A novel cholesterol biosensor was fabricated on hydrophobic ionic liquid (IL)/aqueous solution interface. The hydrophobic IL thin film played a signal amplification role because it not only enriched the cholesterol from the aqueous solution, but also immobilized matrix for cholesterol oxidase (ChOx). Prussian blue (PB) as advanced sensing materials was used as effective low-potential electron transfer mediation toward hydrogen peroxide (H2O2). The fabricated IL-ChOx/PB/Glassy carbon electrode (GCE) was characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammogram (CV), respectively. And it exhibited a linear response to cholesterol in the range of 0.01–0.40 mM with a detection limit of 4.4 μM. In addition, the kinetics behavior of cholesterol at IL-Chox/PB/GCE electrode was examined, and the electrocatalytic mechanism was proposed as shown in first scheme. ChOx immobilized in hydrophobic IL thin film was used as the first electrocatalyst for the cholesterol into H2O2, and the PB film onto the GCE was used as the second electrocatalyst for the 2e− reduction of the produced H2O2 into H2O

  15. Imidazolium Ionic Liquid Functionalized Carbon Nanotubes for Improved Interfacial Charge Transfer and Simultaneous Determination of Dihydroxybenzene Isomers

    Directory of Open Access Journals (Sweden)

    Huan Wei

    2016-05-01

    Full Text Available In this paper; an imidazolium ionic liquid (IL is used to functionalize multi-walled carbon nanotubes (MWNTs by covalent bonding on the MWNT surface. The functionalization not only provides a hydrophilic surface for ion accessibility but also prevents the aggregation of MWNTs. The IL-functionalized MWNTs were then applied for the electrochemical determination of the dihydroxybenzene isomers hydroquinone (HQ; catechol (CC; and resorcinol (RC, exhibiting excellent recognition ability towards the three compounds. The linear calibration ranges for HQ; CC and RC are 0.9–150 μM; 0.9–150 μM and 1.9–145 μM and the detection limits are found to be 0.15 μM for HQ; 0.10 μM for CC and 0.38 μM for RC based on S/N of 3. The proposed electrochemical sensor was also found to be useful for the determination of the dihydroxybenzene isomers in Yellow River water with reliable recovery.

  16. Imidazolium Ionic Liquid Functionalized Carbon Nanotubes for Improved Interfacial Charge Transfer and Simultaneous Determination of Dihydroxybenzene Isomers.

    Science.gov (United States)

    Wei, Huan; Wu, Xiao-Shuai; Wen, Guo-Yun; Qiao, Yan

    2016-01-01

    In this paper; an imidazolium ionic liquid (IL) is used to functionalize multi-walled carbon nanotubes (MWNTs) by covalent bonding on the MWNT surface. The functionalization not only provides a hydrophilic surface for ion accessibility but also prevents the aggregation of MWNTs. The IL-functionalized MWNTs were then applied for the electrochemical determination of the dihydroxybenzene isomers hydroquinone (HQ); catechol (CC); and resorcinol (RC), exhibiting excellent recognition ability towards the three compounds. The linear calibration ranges for HQ; CC and RC are 0.9-150 μM; 0.9-150 μM and 1.9-145 μM and the detection limits are found to be 0.15 μM for HQ; 0.10 μM for CC and 0.38 μM for RC based on S/N of 3. The proposed electrochemical sensor was also found to be useful for the determination of the dihydroxybenzene isomers in Yellow River water with reliable recovery. PMID:27187344

  17. Chromatography as a data source for biphasic green solvent systems: Distribution of low-volatility organic nonelectrolytes between ionic liquids and supercritical carbon dioxide

    Czech Academy of Sciences Publication Activity Database

    Planeta, Josef; Karásek, Pavel; Roth, Michal

    Frankfurt a/M: DECHEMA, 2006. s. 107. [ACHEMA 2006. 28th International Exhibition-Congress on Chemical Engineering, Environmental Protection and Biotechnology. 15.05.2006-19.05.2006, Frankfurt a/M] R&D Projects: GA AV ČR IAA4031301; GA AV ČR KJB400310504; GA ČR GA203/05/2106 Keywords : ionic liquid * supercritical carbon dioxide * solute partition coefficient Subject RIV: CF - Physical ; Theoretical Chemistry

  18. Fixation of CO2 by electrocatalytic reduction to synthesis of dimethyl carbonate in ionic liquid using effective silver-coated nanoporous copper composites

    Institute of Scientific and Technical Information of China (English)

    Xuan Yun Wang; Su Qin Liu; Ke Long Huang; Qiu Ju Feng; De Lai Ye; Bing Liu; Jin Long Liu; Guan Hua Jin

    2010-01-01

    With high surface area, open porosity and high efficiency, a catalyst was prepared and firstly employed in electrocatalytic reduction of CO2 and electrosynthesis of dimethyl carbonate (DMC). The electrochemical property for electrocatalytic reduction of CO2 in ionic liquid was studied by cyclic voitammogram (CV). The effects of various reaction variables like temperature, working potential and cathode materials on the electrocatalytic performance were also investigated. 80% yield of DMC was obtained under the optimal reaction conditions.

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

    Science.gov (United States)

    Perez, Carlos R.

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

  20. Ionic liquids for enzymatic sensing

    OpenAIRE

    Fraser, Kevin J.

    2012-01-01

    Point-of-care (POC) glucose biosensors play an important role in the management of blood sugar levels in patients with diabetes. One of the most commonly used enzymes in glucose biosensors is Glucose Oxidase (GOx). It is a biorecognition enzyme, which recognises the glucose molecule and acts as a catalyst to produce gluconic acid and hydrogen peroxide in the presence of glucose and oxygen. Ionic liquids (ILs) have evolved as a new type of solvent for biocatalysis, mainly due to their uniq...

  1. Application of Ionic Liquids in Hydrometallurgy

    OpenAIRE

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

    2014-01-01

    Ionic liquids, low temperature molten salts, have various advantages manifesting themselves as durable and environmentally friendly solvents. Their application is expanding into various fields including hydrometallurgy due to their unique properties such as non-volatility, inflammability, low toxicity, good ionic conductivity, and wide electrochemical potential window. This paper reviews previous literatures and our recent results adopting ionic liquids in extraction, synthesis and processing...

  2. Mercury determination in urine samples by gold nanostructured screen-printed carbon electrodes after vortex-assisted ionic liquid dispersive liquid-liquid microextraction.

    Science.gov (United States)

    Fernández, Elena; Vidal, Lorena; Costa-García, Agustín; Canals, Antonio

    2016-04-01

    A novel approach is presented to determine mercury in urine samples, employing vortex-assisted ionic liquid dispersive liquid-liquid microextraction and microvolume back-extraction to prepare samples, and screen-printed electrodes modified with gold nanoparticles for voltammetric analysis. Mercury was extracted directly from non-digested urine samples in a water-immiscible ionic liquid, being back-extracted into an acidic aqueous solution. Subsequently, it was determined using gold nanoparticle-modified screen-printed electrodes. Under optimized microextraction conditions, standard addition calibration was applied to urine samples containing 5, 10 and 15 μg L(-1) of mercury. Standard addition calibration curves using standards between 0 and 20 μg L(-1) gave a high level of linearity with correlation coefficients ranging from 0.990 to 0.999 (N = 5). The limit of detection was empirical and statistically evaluated, obtaining values that ranged from 0.5 to 1.5 μg L(-1), and from 1.1 to 1.3 μg L(-1), respectively, which are significantly lower than the threshold level established by the World Health Organization for normal mercury content in urine (i.e., 10-20 μg L(-1)). A certified reference material (REC-8848/Level II) was analyzed to assess method accuracy finding 87% and 3 μg L(-1) as the recovery (trueness) and standard deviation values, respectively. Finally, the method was used to analyze spiked urine samples, obtaining good agreement between spiked and found concentrations (recovery ranged from 97 to 100%). PMID:26995639

  3. Optimization of modified carbon paste electrode with multiwalled carbon nanotube/ionic liquid/cauliflower-like gold nanostructures for simultaneous determination of ascorbic acid, dopamine and uric acid

    Energy Technology Data Exchange (ETDEWEB)

    Afraz, Ahmadreza [Department of Physical Chemistry, Faculty of Chemistry, Bu-Ali Sina University, P.O. Box 65174, Hamedan (Iran, Islamic Republic of); Rafati, Amir Abbas, E-mail: aa_rafati@basu.ac.ir [Department of Physical Chemistry, Faculty of Chemistry, Bu-Ali Sina University, P.O. Box 65174, Hamedan (Iran, Islamic Republic of); Najafi, Mojgan [Department of Materials Engineering, Hamedan University of Technology (HUT), 65169 Hamedan (Iran, Islamic Republic of)

    2014-11-01

    We describe the modification of a carbon paste electrode (CPE) with multiwalled carbon nanotubes (MWCNTs) and an ionic liquid (IL). Electrochemical studies by using a D-optimal mixture design in Design-Expert software revealed an optimized composition of 60% graphite, 14.2% paraffin, 10.8% MWCNT and 15% IL. The optimal modified CPE shows good electrochemical properties that are well matched with model prediction parameters. In the next step, the optimized CPE was modified with gold nanostructures by applying a double-pulse electrochemical technique. The resulting electrode was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and electrochemical impedance spectroscopy. It gives three sharp and well-separated oxidation peaks for ascorbic acid (AA), dopamine (DA), and uric acid (UA). The sensor enables simultaneous determination of AA, DA and UA with linear responses from 0.3 to 285, 0.08 to 200, and 0.1 to 450 μM, respectively, and with 120, 30 and 30 nM detection limits (at an S/N of 3). The method was successfully applied to the determination of AA, DA, and UA in spiked samples of human serum and urine. - Highlights: • New method for simultaneous determination of AA, DA and UA was developed. • MWCNT/ionic liquid/cauliflower-like Au nanostructure was used for CPE modification. • Optimization of electrode composition was done by Design-Expert software. • The pH effect, peak separation mechanism and real samples was thoroughly studied.

  4. Optimization of modified carbon paste electrode with multiwalled carbon nanotube/ionic liquid/cauliflower-like gold nanostructures for simultaneous determination of ascorbic acid, dopamine and uric acid

    International Nuclear Information System (INIS)

    We describe the modification of a carbon paste electrode (CPE) with multiwalled carbon nanotubes (MWCNTs) and an ionic liquid (IL). Electrochemical studies by using a D-optimal mixture design in Design-Expert software revealed an optimized composition of 60% graphite, 14.2% paraffin, 10.8% MWCNT and 15% IL. The optimal modified CPE shows good electrochemical properties that are well matched with model prediction parameters. In the next step, the optimized CPE was modified with gold nanostructures by applying a double-pulse electrochemical technique. The resulting electrode was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and electrochemical impedance spectroscopy. It gives three sharp and well-separated oxidation peaks for ascorbic acid (AA), dopamine (DA), and uric acid (UA). The sensor enables simultaneous determination of AA, DA and UA with linear responses from 0.3 to 285, 0.08 to 200, and 0.1 to 450 μM, respectively, and with 120, 30 and 30 nM detection limits (at an S/N of 3). The method was successfully applied to the determination of AA, DA, and UA in spiked samples of human serum and urine. - Highlights: • New method for simultaneous determination of AA, DA and UA was developed. • MWCNT/ionic liquid/cauliflower-like Au nanostructure was used for CPE modification. • Optimization of electrode composition was done by Design-Expert software. • The pH effect, peak separation mechanism and real samples was thoroughly studied

  5. Ionic Liquids: Green Solvents for Chemical Processing

    OpenAIRE

    Antonia Pérez de los Ríos; Angel Irabien; Frank Hollmann; Francisco José Hernández Fernández

    2013-01-01

    Ionic liquids are organic salts, usually consisting of an organic cation and a polyatomic inorganic anion, which are liquid under 100∘ C. The most relevant properties of ionic liquids are their almost negligible vapour pressure. Furthermore, their physical and chemical properties can be fine-tuned by the adequate selection of the cation and anion constituents. Ionic liquids have been recognized as environmental benign alternative to volatile organic solvents. Applicati...

  6. Quantized Friction across Ionic Liquid Thin Films

    OpenAIRE

    Smith, Alexander M.; Lovelock, Kevin R. J.; Gosvami, Nitya Nand; Welton, Tom; Perkin, Susan

    2013-01-01

    Ionic liquids, salts in the liquid state under ambient conditions, are of great interest as precision lubricants. Ionic liquids form layered structures at surfaces, yet it is not clear how this nano-structure relates to their lubrication properties. We measured the friction force between atomically smooth solid surfaces across ionic liquid films of controlled thickness in terms of the number of ion layers. Multiple friction-load regimes emerge, each corresponding to a different number of ion ...

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

    OpenAIRE

    Xiaolin Xie; Yingkui Yang; Rengui Peng; Yuanzhen Wang; Wei Tang

    2013-01-01

    Carbon nanotubes (CNTs) and graphene sheets are the most promising fillers for polymer nanocomposites due to their superior mechanical, electrical, thermal optical and gas barrier properties, as well as high flame-retardant efficiency. The critical challenge, however, is how to uniformly disperse them into the polymer matrix to achieve a strong interface for good load transfer between the two. This problem is not new but more acute in CNTs and graphene, both because they are intrinsically ins...

  8. Ionic Liquids to Replace Hydrazine

    Science.gov (United States)

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

    2011-01-01

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

  9. Supported Ionic Liquid Phase (SILP) catalysis

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Haumann, Marco;

    2006-01-01

    Applications of ionic liquids to replace conventional solvents in homogeneous transition-metal catalysis have increased significantly during the last decade. Biphasic ionic liquid/organic liquid systems offer advantages with regard to product separation, catalyst stability, and recycling but...... utilise in the case of fast chemical reactions only a small amount of expensive ionic liquid and catalyst. The novel Supported Ionic Liquid Phase (SILP) catalysis concept overcomes these drawbacks and allows the use of fixed-bed reactors for continuous reactions. In this Microreview the SILP catalysis...

  10. New catalytic systems based on carbon nanotubes supported ionic liquid phase

    OpenAIRE

    Rodriguez Perez, Laura

    2009-01-01

    Récemment, les liquides ioniques ont attiré l'attention de la communauté scientifique de la catalyse homogène en tant que solvants répondant aux principes de la chimie verte. De par leur nature chargée, ces phases ioniques sont idéales pour des réactions biphasiques avec des substrats organiques et permettent une récupération facile du catalyseur. Leur caractère ionique leur confère une organisation spatiale à l'échelle nanométrique permettant des phénomènes de solvatations particuliers et un...

  11. Electrochemical performance of hard carbon negative electrodes for ionic liquid-based sodium ion batteries over a wide temperature range

    International Nuclear Information System (INIS)

    Sodium ion batteries (SIBs) have been attracting much attention as promising next-generation energy storage devices for large-scale applications. The major safety issue with SIBs, which arises from the flammability and volatility of conventional organic solvent-based electrolytes, is resolved by adopting an ionic liquid (IL) electrolyte. However, there are only a few reports on the study of negative electrodes in ILs. Here, we report the electrochemical performance of a hard carbon (HC) negative electrode in Na[FSA]-[C3C1pyrr][FSA] (FSA = bis(fluorosulfonyl)amide, C3C1pyrr = N-methyl-N-propylpyrrolidinium) IL over a wide temperature range of −10 °C to 90 °C. High-temperature operation, which is realized for the first time by using an IL, can take full advantage of the high capacity of HC even at a very high discharge rate of 1000 mA (g-HC)−1: the discharge capacity is 230 mAh (g-HC)−1 at 90 °C and 25 mAh (g-HC)−1 at 25 °C. Moreover, surprisingly stable cycleability is observed for the HC electrode at 90 °C, i.e. a capacity retention ratio of 84% after 500 cycles. Finally, a high full-cell voltage of 2.8 V and stable full-cell operation with Coulombic efficiency higher than 99% are achieved for the first time when using NaCrO2 as the positive electrode at 90 °C

  12. Electrochemical oxidation of adenosine-5 Prime -triphosphate on a chitosan-graphene composite modified carbon ionic liquid electrode and its determination

    Energy Technology Data Exchange (ETDEWEB)

    Sun Wei, E-mail: swyy26@hotmail.com [College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, 571158 (China); College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Liu Jun; Wang Xiuzhen; Li Tongtong; Li Guangjiu; Wu Jie [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Zhang Liqi [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2012-10-01

    In this paper a new electrochemical method was proposed for the determination of adenosine-5 Prime -triphosphate (ATP) based on a chitosan (CTS) and graphene (GR) composite film modified carbon ionic liquid electrode (CTS-GR/CILE). CILE was fabricated by using ionic liquid 1-butyl-3-methylimidazolium dihydrogen phosphate ([BMIM]H{sub 2}PO{sub 4}) as the binder, which was further modified by GR and CTS composite. The modified electrode exhibited an excellent electrocatalytic activity toward the oxidation of ATP with the increase of the oxidation peak current and the decrease of the oxidation peak potential. The electrochemical parameters of ATP on CTS-GR/CILE were calculated with the electron transfer coefficient ({alpha}) as 0.329, the electron transfer number (n) as 2.15, the apparent heterogeneous electron transfer rate constant (ks) as 3.705 Multiplication-Sign 10{sup -5} s{sup -1} and the surface coverage ({Gamma}{sub T}) as 9.33 Multiplication-Sign 10{sup -10} mol cm{sup -2}. Under the optimal conditions the oxidation peak current was proportional to ATP concentration in the range from 1.0 Multiplication-Sign 10{sup -6} to 1.0 Multiplication-Sign 10{sup -3} M with the detection limit of 0.311 {mu}M (S/N = 3). The proposed electrode showed excellent reproducibility, stability, anti-interference ability and further successfully applied to the ATP injection sample detection. - Highlights: Black-Right-Pointing-Pointer Ionic liquid [BMIM]H{sub 2}PO{sub 4} based carbon ionic liquid electrode (CILE) was prepared. Black-Right-Pointing-Pointer Graphene modified CILE was fabricated for the sensitive electrochemical detection of ATP. Black-Right-Pointing-Pointer Good electrocatalytic ability to the ATP oxidation was achieved. Black-Right-Pointing-Pointer Detection of 5 Prime -ATP in commercial injection samples with satisfactory results.

  13. Solvatochromic Study on Binary Solvent Mixtures with Ionic Liquids

    Science.gov (United States)

    Koel, Mihkel

    2008-08-01

    Solvent effects on 2,6-dichloro-4-(2,4,6-triphenyl-pyridinium-1-yl)phenolate [ET (33) dye] and 7- diethylamino-3,4-benzophenoxazine-2-one (Nile Red) in binary mixtures of organic solvents (acetone, acetonitrile, propylene carbonate, methanol and ethane-1,2-diol) with 1,3-dialkyl imidazoliumbased ionic liquids were studied by UV-visible spectroscopy. Highly nonlinear behaviour of mixtures of alcohols and ionic liquids was found. A preferential solvation model was applied to the data obtained on solvatochromic shifts over the entire mixing range. It is fitting the data well for alcohol mixtures and for other solvent mixtures with different ionic liquids.

  14. Photochemical Schiemann Reaction in Ionic Liquids

    OpenAIRE

    Heredia-Moya, Jorge; Kirk, Kenneth L.

    2007-01-01

    Photochemical Schiemann reactions of imidazole derivatives 1 and 4 were carried out in 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid [bmim][BF4] as solvent. The effects of temperature, co-solvent and wavelength on the rate of the reaction and product yield were examined. The use of ionic liquid increases the yield of the photochemical fluorodediazoniation reaction of 2 at 0°C. Careful temperature control is necessary to minimize the photodecomposition of the ionic liquid in order...

  15. Rearrangement reactions in ionic liquid media

    OpenAIRE

    Sarmīte Katkeviča

    2009-01-01

    ABSTRACT Ph.D. theses „Rearrangement reactions in ionic liquid media” are devoted to the subject that has gained great actuality and large popularity today - ionic liquids. The research about three different by reaction mechanisms organic transformations – Fries, Beckmann and Claisen rearrangement reactions in ionic liquid media is discussed in the thesis. The novelty of the research is connected with the replacement of organic solvents with environmentally friendly material...

  16. Improved Ionic Liquids as Space Lubricants Project

    Data.gov (United States)

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

  17. Membrane separation of ionic liquid solutions

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-01

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

  18. Simultaneous determination of ascorbic acid, dopamine, and uric acid using a carbon paste electrode modified with multiwalled carbon nanotubes, ionic liquid, and palladium nanoparticles

    International Nuclear Information System (INIS)

    We describe the modification of a carbon paste electrode (CPE) with multiwalled carbon nanotubes (MWCNT) and an ionic liquid (IL). Electrochemical studies revealed an optimized composition of 60 % graphite, 20 % paraffin, 10 % MWCNT and 10 % IL. In a next step, the optimized CPE was modified with palladium nanoparticles (Pd-NPs) by applying a double-pulse electrochemical technique. The resulting electrode was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, cyclic voltammetry, and electrochemical impedance spectroscopy. It gives three sharp and well separated oxidation peaks for ascorbic acid (AA), dopamine (DA), and uric acid (UA), with peak separations of 180 and 200 mV for AA-DA and DA-UA, respectively. The sensor enables simultaneous determination of AA, DA and UA with linear responses from 0.6 to 112, 0.1 to 151, and 0.5 to 225 μM, respectively, and with 200, 30 and 150 nM detection limits (at an S/N of 3). The method was successfully applied to the determination of AA, DA, and UA in spiked samples of human serum and urine. (author)

  19. Immunoassay for serum amyloid A using a glassy carbon electrode modified with carboxy-polypyrrole, multiwalled carbon nanotubes, ionic liquid and chitosan

    International Nuclear Information System (INIS)

    We report on a highly sensitive electrochemical immunoassay for the serum inflammation marker amyloid A (SAA). It is making use of a glassy carbon electrode that was modified with carboxy-endcapped polypyrrole (PPy-α-COOH), multiwalled carbon nanotubes (MWCNTs), ionic liquid and chitosan acting as the support platform. The nanocomposite increases the sensitivity and stability of the assay. Antibody against SAA was immobilized on a monolayer surface consisting of PPy-α-COOH. The electrode material was characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectra, cyclic voltammetry, electrochemical impedance spectroscopy and differential pulse voltammetry. The calibration plot for this assay, when operated at 0.16 V (vs. SCE) and applied to spiked serum samples, is linear in the 0.001 to 900 ng mL−1 SAA concentration range, and the detection limit is as low as 0.3 pg mL−1 (at an S/N ratio of 3). The electrode is stable and highly sensitive. The detection scheme is likely to be applicable to numerous other kinds of immunoassays. (author)

  20. Ionic-Liquid-Tethered Nanoparticles: Hybrid Electrolytes

    KAUST Repository

    Moganty, Surya S.

    2010-10-22

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

  1. Discrimination and simultaneous determination of hydroquinone and catechol by tunable polymerization of imidazolium-based ionic liquid on multi-walled carbon nanotube surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xun; Gao, Weiwei; Zhou, Shenghai; Shi, Hongyan; Huang, Hao; Song, Wenbo, E-mail: wbsong@jlu.edu.cn

    2013-12-17

    Graphical abstract: -- Highlights: •Tunable free radical polymerization of ionic liquid on MWCNT surfaces. •Discrimination of hydroquinone and catechol at functional electrochemical interface. •Excellent performances in simultaneous determination based on cation-π interaction. -- Abstract: Tunable polymerization of ionic liquid on the surfaces of multi-walled carbon nanotubes (MWCNTs) was achieved by a mild thermal-initiation-free radical reaction of 3-ethy-1-vinylimidazolium tetrafluoroborate in the presence of MWCNTs. Successful modification of polymeric ionic liquid (PIL) on MWCNTs surfaces (PIL-MWCNTs) was demonstrated by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and X-ray photoelectron spectroscopy. The resulting PIL-MWCNTs possessed unique features of high dispersity in aqueous solution and tunable thickness of PIL layer, due to positive imidazole groups along PIL chains and controllable ionic liquid polymerization by tuning the ratio of precursor. Based on cation-π interaction between the positive imidazole groups on PIL-MWCNTs surface and hydroquinone (HQ) or catechol (CC), excellent discrimination ability toward HQ and CC and improved simultaneous detection performance were achieved. The linear range for HQ and CC were 1.0 × 10{sup −6} to 5.0 × 10{sup −4} M and 1.0 × 10{sup −6} to 4.0 × 10{sup −4} M, respectively. The detection limit for HQ was 4.0 × 10{sup −7} M and for CC 1.7 × 10{sup −7} M (S/N = 3), correspondingly.

  2. A Sensitive Simultaneous Determination of Adrenalin and Paracetamol on a Glassy Carbon Electrode Coated with a Film of Chitosan/Room Temperature Ionic Liquid/Single-Walled Carbon Nanotubes Nanocomposite%A Sensitive Simultaneous Determination of Adrenalin and Paracetamol on a Glassy Carbon Electrode Coated with a Film of Chitosan/Room Temperature Ionic Liquid/Single-Walled Carbon Nanotubes Nanocomposite

    Institute of Scientific and Technical Information of China (English)

    Babaei, Ali; Babazadeh, Mitra; Afrasiabi, Mohammad

    2011-01-01

    The present work demonstrates that simultaneous determination of adrenalin (AD) and paracetamol (PAR) can be performed on single-walled carbon nanotube/chitosan/ionic liquid modified glassy carbon electrode (SWCNT-CHIT-IL/GCE). The electro-oxidations of AD and PAR were investigated with cyclic voltammetry (CV), differential pulse voltammetry (DPV) and also chronoamperometry (CA) methods. DPV experiments showed that the oxidation peak currents of AD and PAR are proportional to the corresponding concentrations over the 1-580 μmol/L and 0.5-400 μmol/L ranges, respectively. The RSD at a concentration level of 15 μmol/L AD and 15 μmol/L PAR were 1.69% and 1.82%, respectively. Finally the modified electrode was used for simultaneous determination of AD and PAR in real samples with satisfactory results.

  3. Ionic liquid tunes microemulsion curvature.

    Science.gov (United States)

    Liu, Liping; Bauduin, Pierre; Zemb, Thomas; Eastoe, Julian; Hao, Jingcheng

    2009-02-17

    Middle-phase microemulsions formed from cationic dioctadecyldimethylammonium chloride (DODMAC), anionic sodium dodecylsulfate (SDS), n-butanol, and n-heptane were studied. An ionic liquid (IL), 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), was employed as the electrolyte in the aqueous media instead of inorganic salts usually used in microemulsion formulation. Studies have been carried out as a function of the concentrations of [bmim][BF4], n-butanol, total surfactant (cDODMAC+SDS), and temperature on the phase behavior and the ultralow interfacial tensions in which the anionic component is present in excess in the catanionic film. Ultralow interfacial tension measurements confirmed the formation of middle-phase microemulsions and the necessary conditions for stabilizing middle-phase microemulsions. Electrical conductivity, small-angle X-ray scattering (SAXS), and small-angle neutron scattering (SANS) experiments were also performed, indicating that the typical heptane domain size has an average radius of 360 A and the ionic liquid induces softening of the charged catanionic film. Most interestingly, the IL concentration (cIL) is shown to act as an effective interfacial curvature-control parameter, representing a new approach to tuning the formulation of microemulsions and emulsions. The results expand the potential uses of ILs but also point to the design of new ILs that may achieve superefficient control over interfacial and self-assembly systems. PMID:19161325

  4. Ionic liquid coated carbon nanospheres as a new adsorbent for fast solid phase extraction of trace copper and lead from sea water, wastewater, street dust and spice samples.

    Science.gov (United States)

    Tokalıoğlu, Şerife; Yavuz, Emre; Şahan, Halil; Çolak, Süleyman Gökhan; Ocakoğlu, Kasım; Kaçer, Mehmet; Patat, Şaban

    2016-10-01

    In this study a new adsorbent, ionic liquid (1,8-naphthalene monoimide bearing imidazolium salt) coated carbon nanospheres, was synthesized for the first time and it was used for the solid phase extraction of copper and lead from various samples prior to determination by flame atomic absorption spectrometry. The ionic liquid, carbon nanospheres and ionic liquid coated carbon nanospheres were characterized by using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, (1)H NMR and (13)C NMR, Brunauer, Emmett and Teller surface area and zeta potential measurements. Various parameters for method optimization such as pH, adsorption and elution contact times, eluent volume, type and concentration, centrifuge time, sample volume, adsorption capacity and possible interfering ion effects were tested. The optimum pH was 6. The preconcentration factor, detection limits, adsorption capacity and precision (as RSD%) of the method were found to be 300-fold, 0.30µgL(-1), 60mgg(-1) and 1.1% for copper and 300-fold, 1.76µgL(-1); 50.3mgg(-1) and 2.2%, for lead, respectively. The effect of contact time results showed that copper and lead were adsorbed and desorbed from the adsorbent without vortexing. The equilibrium between analyte and adsorbent is reached very quickly. The method was rather selective for matrix ions in high concentrations. The accuracy of the developed method was confirmed by analyzing certified reference materials (LGC6016 Estuarine Water, Reference Material 8704 Buffalo River Sediment, and BCR-482 Lichen) and by spiking sea water, wastewater, street dust and spice samples. PMID:27474302

  5. Quantized friction across ionic liquid thin films.

    Science.gov (United States)

    Smith, Alexander M; Lovelock, Kevin R J; Gosvami, Nitya Nand; Welton, Tom; Perkin, Susan

    2013-10-01

    Ionic liquids - salts in the liquid state under ambient conditions - are of great interest as precision lubricants. Ionic liquids form layered structures at surfaces, yet it is not clear how this nano-structure relates to their lubrication properties. We measured the friction force between atomically smooth solid surfaces across ionic liquid films of controlled thickness in terms of the number of ion layers. Multiple friction-load regimes emerge, each corresponding to a different number of ion layers in the film. In contrast to molecular liquids, the friction coefficients differ for each layer due to their varying composition. PMID:23942943

  6. Synthesis of Cu, Zn and Cu/Zn brass alloy nanoparticles from metal amidinate precursors in ionic liquids or propylene carbonate with relevance to methanol synthesis

    OpenAIRE

    Schütte, K.; H. Meyer; Gemel, Chr.; Barthel, Juri; Fischer, R.A.; Janiak,Chr.

    2014-01-01

    Microwave-induced decomposition of the transition metal amidinates {[Me(C(NiPr)2)]Cu}2 (1) and [Me(C(NiPr)2)]2Zn (2) in the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]) or in propylene carbonate (PC) gives copper and zinc nanoparticles which are stable in the absence of capping ligands (surfactants) for more than six weeks. Co-decomposition of 1 and 2 yields the intermetallic nano-brass phases β-CuZn and γ-Cu3Zn depending on the chosen molar ratios of the precursor...

  7. Aqueous solutions of ionic liquids: microscopic assembly

    NARCIS (Netherlands)

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

    2016-01-01

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

  8. Ionic liquid-in-oil microemulsions.

    Science.gov (United States)

    Eastoe, Julian; Gold, Sarah; Rogers, Sarah E; Paul, Alison; Welton, Tom; Heenan, Richard K; Grillo, Isabelle

    2005-05-25

    Phase stability and small-angle neutron scattering (SANS) data show that surfactant-stabilized nanodomains of a typical ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate [bmim][BF4]) may be dispersed by the nonionic surfactant Triton-X100 in cyclohexane. Analyses of these SANS data are consistent with the formation of ionic liquid-in-oil microemulsion droplets. PMID:15898765

  9. Improved ionic model of liquid uranium dioxide

    NARCIS (Netherlands)

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

    2000-01-01

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

  10. Engineered microorganisms having resistance to ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Ruegg, Thomas Lawrence; Thelen, Michael P.

    2016-03-22

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

  11. Gaseous Hydrocarbon Separations Using Functionalized Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Moura Leila

    2016-03-01

    Full Text Available The functionalization of the side chains on the cation or the anion of an ionic liquid is a common approach to tailor its properties for different processes including the separation of gases. In this paper, we present the current state of the art concerning the usage of ionic liquids for hydrocarbon separations. We also show how the functionalization of ionic liquids or the appropriate anion/cation combinations can contribute to the increase of the performance of the ionic liquids for the separation of gaseous hydrocarbons – either by improving the capacity of the ionic liquid to absorb a given gas or by increasing the selectivity towards a particular hydrocarbon. Original results concerning the usage of olefin-complexing metal salts of lithium (I, nickel (II and copper (II dissolved in ionic liquids for selectively absorbing light olefins are presented. It is observed that the absorption capacity of an imidazolium-based ionic liquid is doubled by the addition of a copper (II salt. This result is compared with the effect of the functionalization of the ionic liquid and the advantages and difficulties of the two approaches are analyzed.

  12. A voltammetric sensor based on NiO/CNTs ionic liquid carbon paste electrode for determination of morphine in the presence of diclofenac

    International Nuclear Information System (INIS)

    A novel ionic liquid modified NiO/CNTs carbon paste electrode (IL/NiO/CNTCPE) had been fabricated by using hydrophilic ionic liquid 1-methyl-3-butylimidazolium chloride [MBIDZ]Cl as a binder. The cyclic voltammogram showed an irreversible oxidation peak at 0.61 V (vs. Ag/AgClsat), which corresponded to the oxidation of morphine. Compared to common carbon paste electrode, the electrochemical response was greatly improved for morphine electrooxidation. This modified electrode exhibited a potent and persistent electron mediating behavior followed by well separated oxidation peaks of morphine and diclofenac. Detection limit of morphine was found to be 0.01 μM using square wave voltammetry (SWV) method. The proposed sensor was successfully applied for the determination of morphine in human urine and pharmaceutical samples. - Graphical abstract: Diclofenac as a nonsteroidal anti-inflammatory drug has been shown to decrease morphine consumption after operation in adults. The addition of regular doses of diclofenac may reduce the need for morphine after abdominal surgery. Therefore, in this study we describe a sensitive electrochemical sensor for simultaneous determination of morphine and diclofenac. - Highlights: • Electrochemical behavior of morphine study using modified carbon paste electrode • The sensor resolved the overlap of morphine and diclofenac • This sensor is also used for the determination of morphine in real samples

  13. A voltammetric sensor based on NiO/CNTs ionic liquid carbon paste electrode for determination of morphine in the presence of diclofenac

    Energy Technology Data Exchange (ETDEWEB)

    Sanati, Afsaneh L. [Department of Chemistry, Graduate University of Advanced Technology, Kerman (Iran, Islamic Republic of); Karimi-Maleh, Hassan, E-mail: h.karimi.maleh@gmail.com [Department of Chemistry, Graduate University of Advanced Technology, Kerman (Iran, Islamic Republic of); Badiei, Alireza [School of Chemistry, College of Science, University of Tehran, Tehran (Iran, Islamic Republic of); Biparva, Pourya [Department of Basic Sciences, Sari Agricultural Sciences and Natural Resources University, Sari (Iran, Islamic Republic of); Ensafi, Ali A. [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2014-02-01

    A novel ionic liquid modified NiO/CNTs carbon paste electrode (IL/NiO/CNTCPE) had been fabricated by using hydrophilic ionic liquid 1-methyl-3-butylimidazolium chloride [MBIDZ]Cl as a binder. The cyclic voltammogram showed an irreversible oxidation peak at 0.61 V (vs. Ag/AgCl{sub sat}), which corresponded to the oxidation of morphine. Compared to common carbon paste electrode, the electrochemical response was greatly improved for morphine electrooxidation. This modified electrode exhibited a potent and persistent electron mediating behavior followed by well separated oxidation peaks of morphine and diclofenac. Detection limit of morphine was found to be 0.01 μM using square wave voltammetry (SWV) method. The proposed sensor was successfully applied for the determination of morphine in human urine and pharmaceutical samples. - Graphical abstract: Diclofenac as a nonsteroidal anti-inflammatory drug has been shown to decrease morphine consumption after operation in adults. The addition of regular doses of diclofenac may reduce the need for morphine after abdominal surgery. Therefore, in this study we describe a sensitive electrochemical sensor for simultaneous determination of morphine and diclofenac. - Highlights: • Electrochemical behavior of morphine study using modified carbon paste electrode • The sensor resolved the overlap of morphine and diclofenac • This sensor is also used for the determination of morphine in real samples.

  14. Performance of Ion-gel Actuator Containing Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    H.Kokubo; Y.Kato; T.Honda; M.Watanabe

    2007-01-01

    1 Results Electroactive polymers (EAPs) driven by transducing electric energy into mechanical energy have been the subjects of recent interest[1]."Ionic liquids",consisting entirely of cation and anion,have characteristic features such as negligible volatility,non-flammability,thermal and chemical stability,and high ionic conductivity.We proposed an EAP actuator utilizing ion-gels[2-3],which consist of ionic liquids and polymers,sandwiching with two carbon material sheets as shown in Fig.1.This electrol...

  15. Ionic liquid incorporating thiosalicylate for metal removal

    Science.gov (United States)

    Wilfred, Cecilia Devi; Mustafa, Fadwa Babiker; Romeli, Fatimah Julia

    2012-09-01

    Ionic liquids are a class of organic molten salts "designer solvents" that are composed totally of anions (inorganic and organic polyatomic) and organic cations. The replacement of volatile organic solvents from a separation process is of utmost importance since the use of a large excess of these solvents is hazardous and creates ecological problem. The new method for metal ion extraction is by using task-specific ionic liquids such as ionic liquids which incorporate thiosalicylate functionality. This paper looks at producing a new cluster of ionic liquids which incorporates thiosalicylate with pyridinium cation. Its thermophysical properties such as density and viscosity in single and binary mixtures are studied. The ionic liquids' capability in metal removal processes is evaluated.

  16. Ionic Liquid-Organic Carbonate Electrolyte Blends To Stabilize Silicon Electrodes for Extending Lithium Ion Battery Operability to 100 °C.

    Science.gov (United States)

    Ababtain, Khalid; Babu, Ganguli; Lin, Xinrong; Rodrigues, Marco-Tulio F; Gullapalli, Hemtej; Ajayan, Pulickel M; Grinstaff, Mark W; Arava, Leela Mohana Reddy

    2016-06-22

    Fabrication of lithium-ion batteries that operate from room temperature to elevated temperatures entails development and subsequent identification of electrolytes and electrodes. Room temperature ionic liquids (RTILs) can address the thermal stability issues, but their poor ionic conductivity at room temperature and compatibility with traditional graphite anodes limit their practical application. To address these challenges, we evaluated novel high energy density three-dimensional nano-silicon electrodes paired with 1-methyl-1-propylpiperidinium bis(trifluoromethanesulfonyl)imide (Pip) ionic liquid/propylene carbonate (PC)/LiTFSI electrolytes. We observed that addition of PC had no detrimental effects on the thermal stability and flammability of the reported electrolytes, while largely improving the transport properties at lower temperatures. Detailed investigation of the electrochemical properties of silicon half-cells as a function of PC content, temperature, and current rates reveal that capacity increases with PC content and temperature and decreases with increased current rates. For example, addition of 20% PC led to a drastic improvement in capacity as observed for the Si electrodes at 25 °C, with stability over 100 charge/discharge cycles. At 100 °C, the capacity further increases by 3-4 times to 0.52 mA h cm(-2) (2230 mA h g(-1)) with minimal loss during cycling. PMID:27237138

  17. Actinide chemistry in ionic liquids.

    Science.gov (United States)

    Takao, Koichiro; Bell, Thomas James; Ikeda, Yasuhisa

    2013-04-01

    This Forum Article provides an overview of the reported studies on the actinide chemistry in ionic liquids (ILs) with a particular focus on several fundamental chemical aspects: (i) complex formation, (ii) electrochemistry, and (iii) extraction behavior. The majority of investigations have been dedicated to uranium, especially for the 6+ oxidation state (UO2(2+)), because the chemistry of uranium in ordinary solvents has been well investigated and uranium is the most abundant element in the actual nuclear fuel cycles. Other actinides such as thorium, neptunium, plutonium, americium, and curiumm, although less studied, are also of importance in fully understanding the nuclear fuel engineering process and the safe geological disposal of radioactive wastes. PMID:22873132

  18. Application of Ionic Liquids in Hydrometallurgy

    Directory of Open Access Journals (Sweden)

    Jesik Park

    2014-08-01

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

  19. Application of graphene-ionic liquid-chitosan composite-modified carbon molecular wire electrode for the sensitive determination of adenosine-5′-monophosphate

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Fan [Key Laboratory of Tropical Medicinal Plant Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China); Gong, Shixing; Xu, Li; Zhu, Huanhuan [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Sun, Zhenfan [Key Laboratory of Tropical Medicinal Plant Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China); Sun, Wei, E-mail: swyy26@hotmail.com [Key Laboratory of Tropical Medicinal Plant Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China)

    2013-12-01

    In this paper, a graphene (GR) ionic liquid (IL) 1-octyl-3-methylimidazolium hexafluorophosphate and chitosan composite-modified carbon molecular wire electrode (CMWE) was fabricated by a drop-casting method and further applied to the sensitive electrochemical detection of adenosine-5′-monophosphate (AMP). CMWE was prepared with diphenylacetylene (DPA) as the modifier and the binder. The properties of modified electrode were examined by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. Electrochemical behaviors of AMP was carefully investigated with enhanced responses appeared, which was due to the presence of GR-IL composite on the electrode surface with excellent electrocatalytic ability. A well-defined oxidation peak of AMP appeared at 1.314 V and the electrochemical parameters were calculated by electrochemical methods. Under the selected conditions, the oxidation peak current of AMP was proportional to its concentration in the range from 0.01 μM to 80.0 μM with the detection limit as 3.42 nM (3σ) by differential pulse voltammetry. The proposed method exhibited good selectivity and was applied to the detection of vidarabine monophosphate injection samples with satisfactory results. - Highlights: • A graphene, ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate and chitosan composite were prepared. • Composite-modified carbon molecular wire electrode was fabricated and characterized. • A sensitive electrochemical method for the detection of adenosine-5′-monophosphate was established.

  20. Application of graphene-ionic liquid-chitosan composite-modified carbon molecular wire electrode for the sensitive determination of adenosine-5′-monophosphate

    International Nuclear Information System (INIS)

    In this paper, a graphene (GR) ionic liquid (IL) 1-octyl-3-methylimidazolium hexafluorophosphate and chitosan composite-modified carbon molecular wire electrode (CMWE) was fabricated by a drop-casting method and further applied to the sensitive electrochemical detection of adenosine-5′-monophosphate (AMP). CMWE was prepared with diphenylacetylene (DPA) as the modifier and the binder. The properties of modified electrode were examined by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. Electrochemical behaviors of AMP was carefully investigated with enhanced responses appeared, which was due to the presence of GR-IL composite on the electrode surface with excellent electrocatalytic ability. A well-defined oxidation peak of AMP appeared at 1.314 V and the electrochemical parameters were calculated by electrochemical methods. Under the selected conditions, the oxidation peak current of AMP was proportional to its concentration in the range from 0.01 μM to 80.0 μM with the detection limit as 3.42 nM (3σ) by differential pulse voltammetry. The proposed method exhibited good selectivity and was applied to the detection of vidarabine monophosphate injection samples with satisfactory results. - Highlights: • A graphene, ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate and chitosan composite were prepared. • Composite-modified carbon molecular wire electrode was fabricated and characterized. • A sensitive electrochemical method for the detection of adenosine-5′-monophosphate was established

  1. The structure of ionic liquids

    CERN Document Server

    Gontrani, Lorenzo

    2014-01-01

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

  2. Ionic liquid lubrication at electrified interfaces

    Science.gov (United States)

    Kong, Lingling; Huang, Wei; Wang, Xiaolei

    2016-06-01

    The lubrication performances of ionic liquids at electrified interfaces have been investigated by using a reciprocating sliding tribometer. Experimental results indicated that the lubricity of the confined ionic liquids was markedly affected by the application of external electric field and strong interface electric field strength could result in high friction. The influence was more pronounced for the ionic liquid with a shorter alkyl side chain in particular. The main reason of the friction increment might be ascribed to the electrically influenced surface adsorption where the charged ions were structured to form robust and ordered layers.

  3. A QuaternaryPoly(ethylene carbonate)-Lithium Bis(trifluoromethanesulfonyl)imide-Ionic Liquid-Silica Fiber Composite Polymer Electrolyte for Lithium Batteries

    International Nuclear Information System (INIS)

    Highlights: • A quaternary PEC-LiTFSI-Pyr14TFSI-Silica fiber electrolyte was prepared by a solvent casting method. • Both electrochemical and mechanical properties were improved by the presence of the Silica fiber. • The electrolyte showed a tLi+ value of 0.36 with an anodic stability extended up to 4.5 V vs. Li/Li+. • A prototype Li/LiFePO4 polymer cell delivered a discharge capacity of about 100 mAh g−1 (75 °C, C/15). - Abstract: Poly(ethylene carbonate) (PEC) is known as an alternating copolymer derived from carbon dioxide (CO2) and an epoxide as monomers. Here, we describe a new quaternary PEC-based composite electrolyte containing lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) salt, N-n-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (Pyr14TFSI) ionic liquid, and an electrospun silica (SiO2) fiber (SiF) with a submicron diameter in view of its possible applications in solid-state Li polymer batteries. A free-standing electrolyte membrane is prepared by a solvent casting method. The Pyr14TFSI ionic liquid enhances the ionic conductivity of the electrolyte as a result of its plasticizing effect. The electrochemical properties, such as ionic conductivity and Li transference number (tLi+), as well as mechanical strength of the electrolyte, are further improved by the SiF. We show that the quaternary electrolyte has a conductivity of the order of 10−7 S cm−1 at ambient temperature and a high tLi+ value of 0.36 with an excellent flexibility. A prototype Li polymer cell using LiFePO4 as a cathode material is assembled and tested. We demonstrate that this battery delivers a reversible charge-discharge capacity close to 100 mAh g−1 at 75 °C and C/15 rate. We believe that this work may pave the road to utilize CO2 as a carbon source for highly-demanded, functional battery materials in future

  4. Ionic liquid polyoxometalates as light emitting materials

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-01-01

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

  5. Ionic Liquid Epoxy Composite Cryotanks Project

    Data.gov (United States)

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

  6. Selective gas absorption by ionic liquids

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  7. Thermodynamic Properties of Caprolactam Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    JIANG Lu; BAI Liguang; ZHU Jiqin; CHEN Biaohua

    2013-01-01

    A series of caprolactam ionic liquids (ILs) containing incorporated halide anions were synthesized.Their physical properties,such as melting points,heats of fusion and heat capacities,were measured by differential scanning calorimeter (DSC).The results indicate that these ionic liquids exhibit proper melting points,high value of heats of fusion,and satisfying heat capacities which are suitable for thermal energy storage applications.

  8. Study of thioglycosylation in ionic liquids

    Directory of Open Access Journals (Sweden)

    Ragauskas Arthur

    2006-06-01

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

  9. Lanthanides and actinides in ionic liquids

    OpenAIRE

    Binnemans, Koen

    2007-01-01

    This lecture gives an overview of the research possibilities offered by combining f-elements (lanthanides and actinides) with ionic liquids [1] Many ionic liquids are solvents with weakly coordinating anions. Solvation of lanthanide and actinide ions in these solvents is different from what is observed in conventional organic solvents and water. The poorly solvating behavior can also lead to the formation of coordination compounds with low coordination numbers. The solvation of f-elements can...

  10. Ionic liquids behave as dilute electrolyte solutions

    OpenAIRE

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

    2013-01-01

    We combine direct surface force measurements with thermodynamic arguments to demonstrate that pure ionic liquids are expected to behave as dilute weak electrolyte solutions, with typical effective dissociated ion concentrations of less than 0.1% at room temperature. We performed equilibrium force–distance measurements across the common ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][NTf2]) using a surface forces apparatus with in situ electrochemical contr...

  11. Dynamics of Ion Transport in Ionic Liquids

    OpenAIRE

    Lee, Alpha A.; Kondrat, Svyatoslav; Vella, Dominic; Goriely, Alain

    2015-01-01

    A gap in understanding the link between continuum theories of ion transport in ionic liquids and the underlying microscopic dynamics has hindered the development of frameworks for transport phenomena in these concentrated electrolytes. Here, we construct a continuum theory for ion transport in ionic liquids by coarse graining a simple exclusion process of interacting particles on a lattice. The resulting dynamical equations can be written as a gradient flow with a mobility matrix that vanishe...

  12. Anomalous Wien Effects in Supercooled Ionic Liquids

    Science.gov (United States)

    Patro, L. N.; Burghaus, O.; Roling, B.

    2016-05-01

    We have measured conductivity spectra of several supercooled monocationic and dicationic ionic liquids in the nonlinear regime by applying ac electric fields with large amplitudes up to about 180 kV /cm . Thereby, higher harmonic ac currents up to the 7th order were detected. Our results point to the existence of anomalous Wien effects in supercooled ionic liquids. Most ionic liquids studied here exhibit a conductivity-viscosity relation, which is close to the predictions of the Nernst-Einstein and Stokes-Einstein equations, as observed for classical strong electrolytes like KCl. These "strong" ionic liquids show a much stronger nonlinearity of the conductivity than classical strong electrolytes. On the other hand, the conductivity-viscosity relation of the ionic liquid [P6 ,6 ,6 ,14][Cl ] points to ion association effects. This "weak" ionic liquid shows a strength of the nonlinear effect, which is comparable to classical weak electrolytes. However, the nonlinearity increases quadratically with the field. We suggest that a theory for explaining these anomalies will have to go beyond the level of Coulomb lattice gas models.

  13. Anomalous Wien Effects in Supercooled Ionic Liquids.

    Science.gov (United States)

    Patro, L N; Burghaus, O; Roling, B

    2016-05-01

    We have measured conductivity spectra of several supercooled monocationic and dicationic ionic liquids in the nonlinear regime by applying ac electric fields with large amplitudes up to about 180  kV/cm. Thereby, higher harmonic ac currents up to the 7th order were detected. Our results point to the existence of anomalous Wien effects in supercooled ionic liquids. Most ionic liquids studied here exhibit a conductivity-viscosity relation, which is close to the predictions of the Nernst-Einstein and Stokes-Einstein equations, as observed for classical strong electrolytes like KCl. These "strong" ionic liquids show a much stronger nonlinearity of the conductivity than classical strong electrolytes. On the other hand, the conductivity-viscosity relation of the ionic liquid [P_{6,6,6,14}][Cl] points to ion association effects. This "weak" ionic liquid shows a strength of the nonlinear effect, which is comparable to classical weak electrolytes. However, the nonlinearity increases quadratically with the field. We suggest that a theory for explaining these anomalies will have to go beyond the level of Coulomb lattice gas models. PMID:27203333

  14. Pyrrole-Terminated Ionic Liquid Surfactant: One Molecule with Multiple Functions for Controlled Synthesis of Diverse Multispecies Co-Doped Porous Hollow Carbon Spheres.

    Science.gov (United States)

    Li, Jian; Zhu, Wei; Ji, Jingwei; Wang, Peng; Lan, Yue; Gao, Ning; Yin, Xianpeng; Wang, Hui; Li, Guangtao

    2016-05-01

    Rationally and efficiently controlling chemical composition, microstructure, and morphology of carbon nanomaterials plays a crucial role in significantly enhancing their functional properties and expending their applications. In this work, a novel strategy for simultaneously controlling these structural parameters was developed on the base of a multifunctional precursor approach, in which the precursor not only serves as carbon source and structure-directing agent, but also contains two heteroatom doping sites. As exemplified by using pyrrole-terminated ionic liquid surfactant as such precursor, in conjunction with sol-gel chemistry this strategy allows for efficiently producing well-defined hollow carbon spheres with controlled microstructure and chemical compositions. Remarkably, the dual-doping sites in confined silica channels provide an exciting opportunity and flexibility to access various doped carbons through simply anion exchange or altering the used oxidative polymerization agent, especially the multispecies codoped materials by combination of the two doping modes. All the results indicate that the described strategy may open up a new avenue for efficiently synthesizing functional carbon materials with highly controllable capability. PMID:27093191

  15. 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.

  16. Ionic liquid gel materials: applications in green and sustainable chemistry

    OpenAIRE

    Marr, Patricia C.; Marr, Andrew C.

    2016-01-01

    Ionic liquid gel materials offer a way to further utilise ionic liquids in technological applications. Combining the controlled and directed assembly of gels, with the diverse applications of ionic liquids, enables the design of a heady combination of functional tailored materials, leading to the development of task specific / functional ionic liquid gels. This review introduces gels and gel classification, focusing on ionic liquid gels and their potential roles in a more sustainable future. ...

  17. Task-specific ionic liquids for solubilizing metal compounds

    OpenAIRE

    Thijs, Ben

    2007-01-01

    The main goal of this PhD thesis was to design new task-specific ionic liquids with the ability to dissolve metal compounds. Despite the large quantity of papers published on ionic liquids, not much is known about the mechanisms of dissolving metals in ionic liquids or about metal-containing ionic liquids. Additionally, many of the commercially available ionic liquids exhibit a very limited solubilizing power for metal compounds, although this is for many applications like electrodeposition a...

  18. Ionic liquids--an overview.

    Science.gov (United States)

    Jenkins, Harry Donald Brooke

    2011-01-01

    A virtually unprecedented exponential burst of activity resulted following the publication, in 1998, of an article by Michael Freeman (Freemantle, M. Chemical & Engineering News, 1998, March 30, 32), which speculated on the role and contribution that ionic liquids (ILs) might make in the future on the development of clean technology. Up until that time only a handful of researchers were routinely engaged in the study of ILs but frenzied activity followed that continues until the present day. Scientists from all disciplines related to Chemistry have now embarked on studies, including theoreticians who are immersed in the aim of improving the "designer role" so that they can tailor ILs to deliver specified properties. This article, whilst not in any sense attempting to be exhaustive, highlights the main features which characterise ILs, presenting these in a form readily assimilated by newcomers to this area of research. An extensive glossary is featured in this article as well as a chronological list which charts the major areas of development. What follows consists of a number of sections briefly describing the role of lLs as solvents, hypergolic fuels, their use in some electrochemical devices such as solar cells and lithium batteries and their use in polymerisation reactions, followed by a concise summary of some of the other roles that they are capable of playing. The role of empirical, volume-based thermodynamics procedures, as well as large scale computational studies on ILs is also highlighted. These developments which are described are remarkable in that they have been achieved in less than a decade and a half although knowledge of these materials has existed for much longer. PMID:22026149

  19. Supported ionic liquid-phase (SILP) catalysis

    DEFF Research Database (Denmark)

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

    2005-01-01

    The concept of supported ionic liquid-phase (SILP) catalysis has been demonstrated for gas- and liquid-phase continuous fixed-bed reactions using rhodium phosphine catalyzed hydroformylation of propene and 1-octene as examples. The nature of the support had important influence on both the catalyt...... performance, i.e. activity and selectivity, as well as stability of the SILP catalysts. Noticeably, a high catalyst ligand content together with presence of ionic liquid solvent are prerequisites for obtaining selective rhodium phosphine SILP catalysts systems.......The concept of supported ionic liquid-phase (SILP) catalysis has been demonstrated for gas- and liquid-phase continuous fixed-bed reactions using rhodium phosphine catalyzed hydroformylation of propene and 1-octene as examples. The nature of the support had important influence on both the catalytic...

  20. Structural and Rotational Dynamics of Carbon Dioxide in 1-Alkyl-3-methylimidazolium Bis(trifluoromethylsulfonyl)imide Ionic Liquids: The Effect of Chain Length.

    Science.gov (United States)

    Giammanco, Chiara H; Yamada, Steven A; Kramer, Patrick L; Tamimi, Amr; Fayer, Michael D

    2016-07-14

    Ionic liquids (ILs) have been proposed as possible carbon dioxide (CO2) capture media; thus, it is useful to understand the dynamics of both the dissolved gas and its IL environment as well as how altering an IL affects these dynamics. With increasing alkyl chain length, it is well-established that ILs obtain a mesoscopic structural feature assigned to polar-apolar segregation, and the change in structure with chain length affects the dynamics. Here, the dynamics of CO2 in a series of 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ILs, in which the alkyl group is ethyl, butyl, hexyl, or decyl, were investigated using ultrafast infrared spectroscopy by measuring the reorientation and spectral diffusion of carbon dioxide in the ILs. It was found that reorientation of the carbon dioxide occurs on three time scales, which correspond to two different time scales of restricted wobbling-in-a-cone motions and a long-time complete diffusive reorientation. Complete reorientation slows with increasing chain length but less than the increases in viscosity of the bulk liquids. Spectral diffusion, measured with two-dimensional IR spectroscopy, is caused by a combination of the liquids' structural fluctuations and reorientation of the CO2. The data were analyzed using a recent theory that takes into account both contributions to spectral diffusion and extracts the structural spectral diffusion. Different components of the structural fluctuations have distinct dependences on the alkyl chain length. All of the dynamics are fast compared to the complete orientational randomization of the bulk ILs, as measured with optical heterodyne-detected optical Kerr effect measurements. The results indicate a hierarchy of constraint releases in the liquids that give rise to increasingly slower dynamics. PMID:27264965

  1. An Amperometric Biosensor of Determination H/sub 2/ O/sub 2/ Based on horseradish peroxidase in carbon nanotubes/ionic liquid

    International Nuclear Information System (INIS)

    A novel amperometric biosensor for the determination of H/sub 2/ O/sub 2/ based on horseradish peroxidase (HRP) in nanocomposite material of muti-walled carbon nanotubes/ionic liquid was explored. Cyclic voltammetry (CV) was used to characterize the performance of the biosensor. Under the optimized experimental conditions, H/sub 2/ O/sub 2/ could be detected in a linear calibration range of 0.5 x 10/sup -6/ M Approximately 6.0 x 10/sup -6/ M with a correlation coefficient of 0.9902 (n = 7), a detection limit of 1.5 x 10/sup -7/ M at 3 sigma and the recovery ratio was of 96.2% ∼ 110.8%, which indicated that the accuracy of this method is also satisfied. The modified electrodes display more excellent electrochemical performance, high sensitivity, good reproducibility, and long-term stability. (author)

  2. A novel magnetic ionic liquid modified carbon nanotube for the simultaneous determination of aryloxyphenoxy-propionate herbicides and their metabolites in water

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Mai; Liu, Donghui; Zhao, Lu; Han, Jiajun; Liang, Yiran; Wang, Peng; Zhou, Zhiqiang, E-mail: zqzhou@cau.edu.cn

    2014-12-10

    Highlights: • A new kind of ionic liquid modified carbon nanotube has been synthesized and applied for simultaneous analysis of AOPPs and their metabolites. • The potential pollutants, such as metabolites of AOPPs, have been analyzed. • The mechanism of absorption has been discussed. • Varieties of experiment factors were optimized and selected. • This method has been successfully applied in the analysis of real water samples. - Abstract: A reliable, sensitive, rapid and environmentally friendly analysis procedure for the simultaneous determination of the analytes with a wide range of polarity in the environmental water was developed by coupling dispersive magnetic solid-phase extraction (d-MSPE) with high-performance liquid chromatography (HPLC)–diode array detector (DAD) and ultra-high pressure liquid chromatography (UHPLC)-triple quadrupole mass spectrometer (MS/MS), in this work. Magnetic ionic liquid modified multi-walled carbon nanotubes (m-IL-MWCNTs) were prepared by spontaneous assembly of magnetic nanoparticles and imidazolium-modified carbon nanotubes, and used as the sorbent of d-MSPE to simultaneously extract aryloxyphenoxy-propionate herbicides (AOPPs) and their polar acid metabolites due to the excellent π–π electron donor–acceptor interactions and anion exchange ability. The factors, including the amount of sorbent, pH of the sample solution, extraction time and the volume of elution solvent were investigated. Under the optimized conditions, the proposed d-MSPE coupling to HPLC–DAD system had a satisfactory performance, the limits of detection (LODs, defined as the signal to noise ratio of 3) and the limits of quantification (LOQs, defined as the signal to noise ratio of 10) for analytes in Milli-Q water were in the range of 2.8–14.3 and 9.8–43.2 μg L{sup −1} respectively. Calibration curves were linear (r{sup 2} > 0.998) over the concentration range from 0.02 to 1 mg L{sup −1}. The recoveries of the eight analytes ranged

  3. Stability of polypyrrole soft actuators in ionic liquids

    Science.gov (United States)

    Kaneto, Keiicgi; Takashima, Wataru

    2012-04-01

    Characteristics of electrochemomechanical deformation (ECMD) of polypyrrole films using ionic liquids are reported. The PPy film prepared by electrodeposition in an ionic liquid (1-Butyl-1-methylpyrrolidinium bis(trifluorometylsulfonyl)imide, BMPTFSI) was compact and high density. The other film prepared from LiTSFI/methyl benzoate and dimethyl phthalate mixed solvents was porous and low density. Both films demonstrated a stable ECMD in the ionic liquid. The strain of ECMD was 3-5% and superimposed on a creeping, showing a typical behaviour of cation movement. The Strains of ECMD in both films operated in a mixed electrolyte of BMPTFSI and propylene carbonate were enhanced up to 17- 25 %, showing anion movement. However, the large strain decreased upon several electrochemical cycles. The results were discussed in terms of swelling of the PPy film by solvents and loss of electrochemical activity.

  4. Water Contaminant Mitigation in Ionic Liquid Propellant

    Science.gov (United States)

    Conroy, David; Ziemer, John

    2009-01-01

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

  5. Supported ionic liquid-phase (SILP) catalysis

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Wasserscheid, P.; van Hal, R.

    The concept of supported ionic liquid-phase (SILP) catalysis has been demonstrated for gas- and liquid-phase continuous fixed-bed reactions using rhodium phosphine catalyzed hydroformylation of propene and 1-octene as examples. The nature of the support had important influence on both the catalytic...... performance, i.e. activity and selectivity, as well as stability of the SILP catalysts. Noticeably, a high catalyst ligand content together with presence of ionic liquid solvent are prerequisites for obtaining selective rhodium phosphine SILP catalysts systems....

  6. Key Developments in Ionic Liquid Crystals

    Science.gov (United States)

    Alvarez Fernandez, Alexandra; Kouwer, Paul H. J.

    2016-01-01

    Ionic liquid crystals are materials that combine the classes of liquid crystals and ionic liquids. The first one is based on the multi-billion-dollar flat panel display industry, whilst the latter quickly developed in the past decades into a family of highly-tunable non-volatile solvents. The combination yields materials with a unique set of properties, but also with many challenges ahead. In this review, we provide an overview of the key concepts in ionic liquid crystals, particularly from a molecular perspective. What are the important molecular parameters that determine the phase behavior? How should they be introduced into the molecules? Finally, which other tools does one have to realize specific properties in the material? PMID:27196890

  7. The Research Progress of CO2 Capture with Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    赵志军; 董海峰; 张香平

    2012-01-01

    Due to their negligible volatility, reasonable thermal stability, strong dissolubility, wide liquid range and tunability of structure and property, ionic liquids have been regarded as emerging candidate reagents for CO2 cap- ture from industries gases. In this review, the research progresses in CO2 capture using conventional ionic liquids,functionalized ionic liquids, supported ionic-liquids membranes, polymerized ionic liquids and mixtures of ionic liquids with some molecular solvents were investigated and reviewed. Discussion of relevant research fields was presented and the future developments were suggested.

  8. Dual Ionic and Organic Nature of Ionic Liquids

    Science.gov (United States)

    Shi, Rui; Wang, Yanting

    2016-01-01

    Inherited the advantages of inorganic salts and organic solvents, ionic liquids (ILs) exhibit many superior properties allowing them promising green solvents for the future. Although it has been widely acknowledged that the unique features of ILs originate from their dual ionic and organic nature, its microscopic physical origin still remains blurry. In this work, by comparing the ion/molecule cage structures obtained from molecular dynamics simulations for seven prototypic liquids—a molten inorganic salt, four ILs, a strongly polar organic solvent, and a weakly polar organic solvent, we have revealed that the depth of the cage energy landscape characterizes the ionic nature of ILs, whereas the slope and curvature of its mimimum determine the organic nature of ILs. This finding advances our understanding of ILs and thus will help their efficient utilization as well as the systematic design of novel functionalized ILs.

  9. Ionic Liquid Extractions of Soil Organic Matter

    Science.gov (United States)

    Patti, Antonio; Macfarlane, Douglas; Clarke, Michael

    2010-05-01

    A large range of ionic liquids with the ability to dissolve different classes of natural biopolymers (e.g. cellulose, lignin, protein) have been reported in the literature. These have the potential to isolate different fractions of soil organic matter, thus yielding novel information that is not available through other extraction procedures. The ionic liquids dimethylammonium dimethylcarbamate (DIMCARB), alkylbenzenesulfonate and 1-butyl-3methylimidazolium chloride (Bmim Cl) can solubilise selected components of soil organic matter. Soil extractions with these materials showed that the organic matter recovered showed chemical properties that were consistent with humic substances. These extracts had a slightly different organic composition than the humic acids extracted using the traditional International Humic Substances Society (IHSS) method. The ionic liquids also solubilised some inorganic matter from the soil. Humic acids recovered with alkali were also partially soluble in the ionic liquids. DIMCARB appeared to chemically interfere with organic extract, increasing the level of nitrogen in the sample. It was concluded that the ionic liquid Bmim Cl may function as a useful solvent for SOM, and may be used to recover organic matter of a different character to that obtained with alkali

  10. 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.

  11. Desulfurization of oxidized diesel using ionic liquids

    Science.gov (United States)

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

    2014-10-01

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

  12. TETRAALKYLPHOSPHONIUM POLYOXOMETALATES AS NOVEL IONIC LIQUIDS.

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-11-30

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

  13. Layer by layer assembly of catalase and amine-terminated ionic liquid onto titanium nitride nanoparticles modified glassy carbon electrode: Study of direct voltammetry and bioelectrocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Saadati, Shagayegh [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Salimi, Abdollah, E-mail: absalimi@uok.ac.ir [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Research Center for Nanotechnology, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Hallaj, Rahman; Rostami, Amin [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of)

    2012-11-13

    Highlights: Black-Right-Pointing-Pointer Catalase and amine-terminated ionic liquid were immobilized to GC/TiNnp with LBL assembly method. Black-Right-Pointing-Pointer First a thin layer of NH{sub 2}-IL is covalently attached to GC/TiNnp electrode using electro-oxidation. Black-Right-Pointing-Pointer With alternative assemble of IL and catalase with positive and negative charged, multilayer was formed. Black-Right-Pointing-Pointer Immobilized catalase shows excellent electrocatalytic activity toward H{sub 2}O{sub 2} reduction. Black-Right-Pointing-Pointer Biosensor response is directly correlated to the number of bilayers. - Abstract: A novel, simple and facile layer by layer (LBL) approach is used for modification of glassy carbon (GC) electrode with multilayer of catalase and nanocomposite containing 1-(3-Aminopropyl)-3-methylimidazolium bromide (amine terminated ionic liquid (NH{sub 2}-IL)) and titanium nitride nanoparticles (TiNnp). First a thin layer of NH{sub 2}-IL is covalently attached to GC/TiNnp electrode using electro-oxidation method. Then, with alternative self assemble positively charged NH{sub 2}-IL and negatively charged catalase a sensitive H{sub 2}O{sub 2} biosensor is constructed, whose response is directly correlated to the number of bilayers. The surface coverage of active catalase per bilayer, heterogeneous electron transfer rate constant (k{sub s}) and Michaelis-Menten constant (K{sub M}) of immobilized catalase were 3.32 Multiplication-Sign 10{sup -12} mol cm{sup -2}, 5.28 s{sup -1} and 1.1 mM, respectively. The biosensor shows good stability, high reproducibility, long life-time, and fast amperometric response with the high sensitivity of 380 {mu}A mM{sup -1} cm{sup -2} and low detection limit of 100 nM at concentration range up to 2.1 mM.

  14. Functional ionic liquids; Funktionelle ionische Fluessigkeiten

    Energy Technology Data Exchange (ETDEWEB)

    Baecker, Tobias

    2012-07-01

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

  15. Structure of room temperature ionic liquids.

    Science.gov (United States)

    Yethiraj, Arun

    2016-10-19

    The structure of room temperature ionic liquids is studied using molecular dynamics simulations and integral equation theory. Three ionic liquids 1-alkyl-3-methylimidazolium hexfluorophosphate, [C n MIM] [PF6], for n  =  1, 4, and 8, are studied using a united atom model of the ions. The primary interest is a study of the pair correlation functions and a test of the reference interaction site model theory. There is liquid-like ordering in the liquid that arises from electrostatic attractions and steric packing considerations. The theory is not in quantitative agreement with the simulation results and underestimates the degree of liquid-like order. A pre-peak in the static structure factor is seen in both simulations and theory, suggesting that this is a geometric effect arising from a packing of the alkyl chains. PMID:27546807

  16. Non-enzymatic sensing of uric acid using a carbon nanotube ionic-liquid paste electrode modified with poly(β-cyclodextrin)

    International Nuclear Information System (INIS)

    We describe a nonenzymatic electrochemical sensor for uric acid. It is based on a carbon nanotube ionic-liquid paste electrode modified with poly(β-cyclodextrin) that was prepared in-situ by electropolymerization. The functionalized multi-walled carbon nanotubes and the surface morphology of the modified electrodes were characterized by transmission electronic microscopy and scanning electron microscopy. The electrochemical response of uric acid was studied by cyclic voltammetry and linear sweep voltammetry. The effects of scan rate, pH value, electropolymerization cycles and accumulation time were also studied. Under optimized experimental conditions and at a working voltage of 500 mV vs. Ag/AgCl (3 M KCl), response to uric acid is linear in the 0.6 to 400 μΜ and in the 0.4 to 1 mΜ concentration ranges, and the detection limit is 0.3 μΜ (at an S/N of 3). The electrode was successfully applied to the detection of uric acid in (spiked) human urine samples. (author)

  17. Theinfluence of a hierarchical porous carbon network on the coherent dynamics of a nanoconfined room temperature ionic liquid: A neutron spin echo and atomistic simulation investigation

    Energy Technology Data Exchange (ETDEWEB)

    Banuelos, Jose Leo [ORNL; Feng, Guang [ORNL; Fulvio, Pasquale F [ORNL; Li, Song [Vanderbilt University, Nashville; Rother, Gernot [ORNL; Arend, Nikolas [ORNL; Faraone, Antonio [National Institute of Standards and Technology (NIST); Dai, Sheng [ORNL; Cummings, Peter T [ORNL; Wesolowski, David J [ORNL

    2014-01-01

    The molecular-scale dynamic properties of the room temperature ionic liquid (RTIL) 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, or [C4mim+ ][Tf2N ], confined in hierarchical microporous mesoporous carbon, were investigated using neutron spin echo (NSE) and molecular dynamics (MD) simulations. Both NSE and MD reveal pronounced slowing of the overall collective dynamics, including the presence of an immobilized fraction of RTIL at the pore wall, on the time scales of these approaches. A fraction of the dynamics, corresponding to RTIL inside 0.75 nm micropores located along the mesopore surfaces, are faster than those of RTIL in direct contact with the walls of 5.8 nm and 7.8 nm cylindrical mesopores. This behavior is ascribed to the near-surface confined-ion density fluctuations resulting from the ion ion and ion wall interactions between the micropores and mesopores as well as their confinement geometries. Strong micropore RTIL interactions result in less-coordinated RTIL within the micropores than in the bulk fluid. Increasing temperature from 296 K to 353 K reduces the immobilized RTIL fraction and results in nearly an order of magnitude increase in the RTIL dynamics. The observed interfacial phenomena underscore the importance of tailoring the surface properties of porous carbons to achieve desirable electrolyte dynamic behavior, since this impacts the performance in applications such as electrical energy storage devices.

  18. Amine-terminated ionic liquid functionalized carbon nanotubes for enhanced interfacial electron transfer of Shewanella putrefaciens anode in microbial fuel cells

    Science.gov (United States)

    Wei, Huan; Wu, Xiao-Shuai; Zou, Long; Wen, Guo-Yun; Liu, Ding-Yu; Qiao, Yan

    2016-05-01

    An amine-terminated ionic liquid (IL-NH2) is applied to functionalize carbon nanotubes (CNTs) for improving the interfacial electron transfer of Shewanella putrefaciens (S. putrefaciens) anode in Microbial fuel cells (MFCs). The introduction of thin layer of ILs does not change the morphology of CNTs a lot but increases surface positive charges as well as nitrogen functional groups of the CNTs based anode. The CNT-IL composite not only improves the adhesion of S. putrefaciens cells but also promotes both of the flavin-mediated and the direct electron transfer between the S. putrefaciens cells and the anode. It is interesting that the CNT-IL is more favorable for the mediated electron transfer than for the direct electron transfer. The CNT-IL/carbon cloth anode delivers 3-fold higher power density than that of CNT anode and shows great long-term stability in the batch-mode S. putrefaciens MFCs. This CNT-IL could be a promising anode material for high performance MFCs.

  19. Two-ply yarn supercapacitor based on carbon nanotube/stainless steel core-sheath yarn electrodes and ionic liquid electrolyte

    Science.gov (United States)

    Lyu, Xiaoming; Su, Fenghua; Miao, Menghe

    2016-03-01

    Linear supercapacitors have great potential as power source in electronic textiles. However, the energy density of most yarn supercapacitors reported so far is still quite low and decreases significantly as the supercapacitor length increases. Here, we report a two-ply yarn supercapacitor based on carbon nanotube/stainless steel core-sheath yarn electrode and ionic liquid electrolyte. The use of IL gel electrolyte widens the potential window of supercapacitor from 1.0 V to 2.7 V. The carbon nanotube/stainless steel core-sheath yarn structure greatly improves the charge transport efficiency and allows the length of the linear supercapacitor to be significantly scaled up. The resulting supercapacitor has shown outstanding electrochemical performances with a high volumetric capacitance of 263.31 F cm-3 and energy density of 6.67×10-2 Wh cm-3. The two-ply yarn supercapacitors are also very flexible and strong for use as sewing thread and for making knots without significant loss of their energy storage capacity.

  20. Ionic liquid-nanoparticle hybrid electrolytes

    KAUST Repository

    Lu, Yingying

    2012-01-01

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

  1. Synthesis and characterization of new ionic liquids

    International Nuclear Information System (INIS)

    In recent years, ionic liquids have been highlighted for its potential in various industrial applications. Among them, the salts of Broensted has a promising profile for the low toxicity, low cost and simple synthesis. This paper presents the synthesis and characterization of new salts of Bronsted with branched (lactate) or large chain anions (oleate) for future use as additives promoters of proton conductivity in fuel cells of ethanol. Experimental data were measured for density, sound velocity and conductivity of pure ionic liquids and mixtures. The density decreases linearly with increasing temperature, and sound velocity shows a similar trend, but not linear. The conductivity increases according to the Arrhenius model with activation energy less than 10 J/mol. Tests NMR, FTIR and TGA confirm ionic structure and thermal stability up to 165 deg C. (author)

  2. Applications of ionic liquids in polymer science and technology

    CERN Document Server

    2015-01-01

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

  3. Preparation and evaluation of cellulose-dissolving magnetic ionic liquid

    OpenAIRE

    MURAOKA, Jin; Kamiya, Noriho; Ito, Yuji; ムラオカ, ジン; カミヤ, ノリホ; イトウ, ユウジ; 村岡, 仁; 神谷, 典穂; 伊東, 祐二

    2013-01-01

    Ionic liquids have attracted attention as potential pretreatment agents in cellulosic biomass processing. Here we report on a new magnetic ionic liquid that can dissolve crystalline cellulose and be collected by a magnet.

  4. VOC and HAP recovery using ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Michael R. Milota : Kaichang Li

    2007-05-29

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

  5. Battery electrolytes based on saturated ring ionic liquids: Physical and electrochemical properties

    International Nuclear Information System (INIS)

    Physical and electrochemical properties of mixtures of ionic liquids based on saturated ring systems with carbonate based solvents were investigated. The conductivity and electrochemical stability of two series of ionic liquids based on piperidinium and pyrrolidinium cations with tetrafluoroborate and bis(trifluorosulfonylimide) anions were evaluated. The effects of the ionic liquid cation, substituent chain length of the cation function group, and the anion type on conductivity and electrochemical stability as determined by cyclic voltammetry were studied. The conductivity was influenced by the substituent chain length of the ionic liquid cation and the solvent carbonate type, where higher conductivities were observed with shorter substituent chains and EC versus PC. The saturated ring ionic liquid–carbonate mixtures may show particular promise for implementation as battery electrolytes due to notable high voltage stabilities, where stability >5.5 V was maintained in the presence of lithium salt. This study should promote development of future safe, high voltage lithium ion battery systems

  6. Introduction on Special Issue: Ionic Liquids

    Czech Academy of Sciences Publication Activity Database

    Jacquemin, J.; Bendová, Magdalena

    2015-01-01

    Roč. 44, 3-4 (2015), s. 379-381. ISSN 0095-9782 Institutional support: RVO:67985858 Keywords : ionic liquids * E. Hála * special issue Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.177, year: 2014

  7. Solvation and Reaction in Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Maroncelli, Mark

    2015-01-15

    The long-range goal of our DOE-sponsored research is to obtain a fundamental understanding of solvation effects on photo-induced charge transfer and related processes. Much of the focus during the past funding period has been on studies of ionic liquids and on characterizing various reactions with which to probe the nature of this interesting new solvent medium.

  8. Ionic liquids - media for polyaniline preparation

    Czech Academy of Sciences Publication Activity Database

    Konyushenko, Elena; Stejskal, Jaroslav; Morávková, Zuzana; Trchová, Miroslava; Prokeš, J.

    Atlanta : Center for Organic Photonics and Electronics - Georgia Institute of Technology, 2012. s. 280. [International Conference on Science and Technology of Synthetic Metals 2012 - ICSM 2012. 08.07.2012-13.07.2012, Atlanta] Institutional support: RVO:61389013 Keywords : polyaniline * ionic liquids Subject RIV: CD - Macromolecular Chemistry

  9. Reactions of Starch in Ionic Liquids

    Science.gov (United States)

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

  10. Esterification of Starch in Ionic Liquids

    Science.gov (United States)

    We shall discuss the use of various ionic liquids in the preparation of starch esters. Starch was reacted with vinyl acetate in different 1-butyl-3-methylimidazolium (bmim) salts as solvents in an effort to produce starches with different acetylation patterns. Overall degree of substitution (DS) w...

  11. Application of Ionic Liquids in Amperometric Gas Sensors.

    Science.gov (United States)

    Gębicki, Jacek; Kloskowski, Adam; Chrzanowski, Wojciech; Stepnowski, Piotr; Namiesnik, Jacek

    2016-01-01

    This article presents an analysis of available literature data on metrological parameters of the amperometric gas sensors containing ionic liquids as an electrolyte. Four mechanism types of signal generation in amperometric sensors with ionic liquid are described. Moreover, this article describes the influence of selected physico-chemical properties of the ionic liquids on the metrological parameters of these sensors. Some metrological parameters are also compared for amperometric sensors with GDE and SPE electrodes and with ionic liquids for selected analytes. PMID:25830724

  12. Synthesis, characterization and thermal properties of thiosalicylate ionic liquids

    Indian Academy of Sciences (India)

    Cecilia Devi Wilfred; Fadwa Babiker Mustafa

    2013-11-01

    In an attempt to produce new functionalized ionic liquids, a series of thiosalicylate ionic liquids based on imidazolium, ammonium, phosphonium, choline and pyrrolidinium cations were synthesized. The compounds were characterized by Infra Red (IR), Nuclear Magnetic Resonance (NMR) and mass spectra (ESI-MS). Their glass-transition temperatures, melting points and decomposition temperatures have been measured. Physicochemical properties of ionic liquids are influenced by alkyl chain length and nature of the cation of ionic liquids.

  13. Synthesis of Cu, Zn and Cu/Zn brass alloy nanoparticles from metal amidinate precursors in ionic liquids or propylene carbonate with relevance to methanol synthesis

    Science.gov (United States)

    Schütte, Kai; Meyer, Hajo; Gemel, Christian; Barthel, Juri; Fischer, Roland A.; Janiak, Christoph

    2014-02-01

    Microwave-induced decomposition of the transition metal amidinates {[Me(C(NiPr)2)]Cu}2 (1) and [Me(C(NiPr)2)]2Zn (2) in the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]) or in propylene carbonate (PC) gives copper and zinc nanoparticles which are stable in the absence of capping ligands (surfactants) for more than six weeks. Co-decomposition of 1 and 2 yields the intermetallic nano-brass phases β-CuZn and γ-Cu3Zn depending on the chosen molar ratios of the precursors. Nanoparticles were characterized by high-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM), dynamic light scattering and powder X-ray diffractometry. Microstructure characterizations were complemented by STEM with spatially resolved energy-dispersive X-ray spectrometry and X-ray photoelectron spectroscopy. Synthesis in ILs yields significantly smaller nanoparticles than in PC. β-CuZn alloy nanoparticles are precursors to catalysts for methanol synthesis from the synthesis gas H2/CO/CO2 with a productivity of 10.7 mol(MeOH) (kg(Cu) h)-1.Microwave-induced decomposition of the transition metal amidinates {[Me(C(NiPr)2)]Cu}2 (1) and [Me(C(NiPr)2)]2Zn (2) in the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]) or in propylene carbonate (PC) gives copper and zinc nanoparticles which are stable in the absence of capping ligands (surfactants) for more than six weeks. Co-decomposition of 1 and 2 yields the intermetallic nano-brass phases β-CuZn and γ-Cu3Zn depending on the chosen molar ratios of the precursors. Nanoparticles were characterized by high-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM), dynamic light scattering and powder X-ray diffractometry. Microstructure characterizations were complemented by STEM with spatially resolved energy-dispersive X-ray spectrometry and X-ray photoelectron spectroscopy. Synthesis in ILs yields significantly smaller nanoparticles than in PC.

  14. Microwave assisted one-step green synthesis of fluorescent carbon nanoparticles from ionic liquids and their application as novel fluorescence probe for quercetin determination

    International Nuclear Information System (INIS)

    In this study, a new sensitive and convenient method for the determination of quercetin based on the fluorescence quenching of fluorescent carbon nanoparticles (CNPs) was developed. The CNPs derived from ionic liquids were prepared using a green and rapid microwave-assisted synthetic approach for the first time. The one-step green preparation process is simple and effective, neither a strong acid solvent nor surface modification reagent is needed, which makes this approach very suitable for large-scale production. The prepared CNPs were characterized by high-resolution transmission electron microscopy, Fourier transform infrared spectrometry, elemental analysis and spectrofluorometry. In NH3–NH4Cl buffer solution (pH 9.47), the fluorescence signals of CNPs decreased obviously with increase of the quercetin concentration. The effect of other coexisting foreign substances on the intensity of CNPs showed a low interference response. Under the optimum conditions, the fluorescence intensity presented a linear response versus quercetin concentration according to the Stern–Volmer equation with an excellent 0.9989 correlation coefficient. The linearity ranged from 2.87×10−6 to 31.57×10−6 mol L−1 with the detection limit (3σ) of 9.88×10−8 mol L−1. The recovery of this method was in the range of 93.3–105.1%. Therefore, the CNPs could to be a promising candidate as a fluorescence probe for the detection of trace levels of quercetin due to their advantages in low-cost production, low cytotoxicity, strong fluorescence and excellent biocompatibility. -- Highlights: ► Fluorescent CNPs were synthesized with microwave pyrolysis approach. ► Ionic liquids were used as sources of carbon and nitrogen for the first time. ► The formation and functionalization of CNPs were accomplished simultaneously. ► CNPs were used as fluorescent probes for the determination of quercetin. ► A sensitive and convenient method based on the fluorescence quenching was developed

  15. Microwave assisted one-step green synthesis of fluorescent carbon nanoparticles from ionic liquids and their application as novel fluorescence probe for quercetin determination

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Deli; Yuan, Danhua [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing 210009 (China); He, Hua, E-mail: dochehua@163.com [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing 210009 (China); Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, China Pharmaceutical University, Nanjing 210009 (China); Gao, Mengmeng [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing 210009 (China)

    2013-08-15

    In this study, a new sensitive and convenient method for the determination of quercetin based on the fluorescence quenching of fluorescent carbon nanoparticles (CNPs) was developed. The CNPs derived from ionic liquids were prepared using a green and rapid microwave-assisted synthetic approach for the first time. The one-step green preparation process is simple and effective, neither a strong acid solvent nor surface modification reagent is needed, which makes this approach very suitable for large-scale production. The prepared CNPs were characterized by high-resolution transmission electron microscopy, Fourier transform infrared spectrometry, elemental analysis and spectrofluorometry. In NH{sub 3}–NH{sub 4}Cl buffer solution (pH 9.47), the fluorescence signals of CNPs decreased obviously with increase of the quercetin concentration. The effect of other coexisting foreign substances on the intensity of CNPs showed a low interference response. Under the optimum conditions, the fluorescence intensity presented a linear response versus quercetin concentration according to the Stern–Volmer equation with an excellent 0.9989 correlation coefficient. The linearity ranged from 2.87×10{sup −6} to 31.57×10{sup −6} mol L{sup −1} with the detection limit (3σ) of 9.88×10{sup −8} mol L{sup −1}. The recovery of this method was in the range of 93.3–105.1%. Therefore, the CNPs could to be a promising candidate as a fluorescence probe for the detection of trace levels of quercetin due to their advantages in low-cost production, low cytotoxicity, strong fluorescence and excellent biocompatibility. -- Highlights: ► Fluorescent CNPs were synthesized with microwave pyrolysis approach. ► Ionic liquids were used as sources of carbon and nitrogen for the first time. ► The formation and functionalization of CNPs were accomplished simultaneously. ► CNPs were used as fluorescent probes for the determination of quercetin. ► A sensitive and convenient method based

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

    NARCIS (Netherlands)

    Sui, Xiaofeng; Hempenius, Mark A.; Vancso, G. Julius

    2012-01-01

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

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

    OpenAIRE

    EeroSalminen; Jyri-PekkaTuomoMikkola

    2014-01-01

    The challenge in preparation of ionic liquids containing a strong alkaline anion is to identify a suitable cation which can tolerate the harsh conditions induced by the anion. In this study, a commercial quaternary ammonium compound (quat) benzalkonium [ADBA] (alkyldimethylbenzylammonium) was used as a cation in the synthesis of different alkaline ionic liquids. In fact, the precursor, benzalkonium chloride, is a mixture of alkyldimethylbenzylammonium chlorides of various alkyl chain lengths ...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-15

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

  19. Hydrogen production from glucose in ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  20. Application of Supported Ionic Liquid Membranes for Biogas Separation.

    Czech Academy of Sciences Publication Activity Database

    Sedláková, Zuzana; Kárászová, Magda; Vejražka, Jiří; Izák, Pavel

    Pardubice: Czech Membrane Platform, 2016 - (Palatý, Z.), s. 80 ISBN 978-80-904517-6-6. [PERMEA and MELPRO Conference 2016. Praha (CZ), 15.05.2016-19.05.2016] R&D Projects: GA ČR GA14-12695S Institutional support: RVO:67985858 Keywords : ionic liquid membrane * biogas upgrading * carbon dioxide removal Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  1. Synthesis of tin nanocrystals in room temperature ionic liquids

    OpenAIRE

    Le Vot, Steven; Dambournet, Damien; Groult, Henri; Ngo, Anh-tu; Petit, Christophe; Rizzi, Cécile; Salzemann, Caroline; Sirieix-Plenet, Juliette; Borkiewicz, Olaf J.; Raymundo-Piñero, Encarnación; Gaillon, Laurent

    2014-01-01

    International audience The aim of this work was to investigate the synthesis of tin nanoparticles (NPs) or tin/carbon composites, in room temperature ionic liquids (RTILs), that could be used as structured anode materials for Li-ion batteries. An innovative route for the synthesis of Sn nanoparticles in such media is successfully developed. Compositions, structures, sizes and morphologies of NPs were characterized by high-energy X-ray diffraction (HEXRD), X-ray photoelectron spectroscopy (...

  2. Effective Permeability of Binary Mixture of Carbon Dioxide and Methane and Pre-Dried Raw Biogas in Supported Ionic Liquid Membranes

    Czech Academy of Sciences Publication Activity Database

    Kárászová, Magda; Sedláková, Zuzana; Friess, K.; Izák, Pavel

    2015-01-01

    Roč. 153, OCT 16 (2015), s. 14-18. ISSN 1383-5866 R&D Projects: GA ČR GA14-12695S; GA MŠk LH14006 Institutional support: RVO:67985858 Keywords : supported ionic liquid membrane * biogas upgrading * real biogas Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.091, year: 2014

  3. Ionic liquid polymer functionalized carbon nanotubes-doped poly(3,4-ethylenedioxythiophene) for highly-efficient solid-phase microextraction of carbamate pesticides.

    Science.gov (United States)

    Wu, Mian; Wang, Liying; Zeng, Baizhao; Zhao, Faqiong

    2016-04-29

    A poly(3,4-ethylenedioxythiophene)-ionic liquid polymer functionalized multiwalled carbon nanotubes (PEDOT-PIL/MWCNTs) composite solid-phase microextraction (SPME) coating was fabricated by electrodeposition. After being dipped in Nafion solution, a Nafion-modified coating was obtained. The outer layer Nafion played a crucial role in enhancing the durability and stability of the coating, thus it was robust enough for replicated extraction for at least 150 times without decrease of extraction performance. The Nafion-modified coating exhibited much higher sensitivity than commercial coatings for the direct extraction of carbamate pesticides in aqueous solutions, due to its strong hydrophobic effect and π-π affinity based enrichment. When it was used for the determination of carbamate pesticides in combination with gas chromatography-flame ionization detection, good linearity (correlation coefficients higher than 0.9981), low limits of detection (15.2-27.2 ng/L) and satisfactory precision (relative standard deviation <8.2%, n=5) were achieved. The developed method was applied to the analysis of four carbamate pesticides in apple and lettuce samples, and acceptable recoveries (i.e. 87.5-106.5%) were obtained for the standard addition. PMID:27036210

  4. Application of poly(acridine orange) and graphene modified carbon/ionic liquid paste electrode for the sensitive electrochemical detection of rutin

    International Nuclear Information System (INIS)

    A carbon/ionic liquid paste electrode (CILPE) prepared by 1-hexylpyridinium hexafluorophosphate as the binder was used as the substrate electrode. A layer of graphene oxide (GO) film was cast on CILPE surface (GO/CILPE) and the electropolymerization of acridine orange (AO) on electrode was further realized by cyclic voltammetry in the potential range from −1.40 V to 1.40 V, which could simultaneously reduce GO to graphene (GR) electrochemically. The fabricated PAO-GR/CILPE exhibited good electrochemical performances with higher conductivity and lower electron transfer resistance. Electrochemical behaviors of rutin were further investigated on the modified electrode in 0.1 mol/L pH 2.0 phosphate buffer solution by cyclic voltammetry with a pair of well-defined redox peaks appeared. The peak-to-peak separation (ΔEp) was calculated as 0.076 V, which proved a fast quasi-reversible electron transfer process and the electrochemical parameters of rutin on PAO-GR/CILPE were calculated. Under the optimal conditions, the linear relationship between the oxidation peak current of rutin and its concentration was obtained in the range from 0.03 to 800.0 μmol/L with the detection limit as 8.33 nmol/L (3σ). The PAO-GR/CILPE showed good selectivity, stability and reproducibility, which was further applied to detect rutin tablet samples with satisfactory results

  5. A sandwich electrochemical immunosensor for Salmonella pullorum and Salmonella gallinarum based on a screen-printed carbon electrode modified with an ionic liquid and electrodeposited gold nanoparticles

    International Nuclear Information System (INIS)

    This article describes an electrochemical immunosensor for rapid determination of Salmonella pullorum and Salmonella gallinarum. The first step in the preparation of the immunosensor involves the electrodeposition of gold nanoparticles used for capturing antibody and enhancing signals. In order to generate a benign microenvironment for the antibody, the ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate was used to modify the surface of a screen-printed carbon electrode (SPCE). The single steps of modification were monitored via cyclic voltammetry and electrochemical impedance spectroscopy. Based on these findings, a sandwich immunoassay was worked out for the two Salmonella species by immobilizing the respective unlabeled antibodies on the SPCE. Following exposure to the analytes, secondary antibody (labeled with HRP) is added to form the sandwich. After adding hydrogen peroxide and thionine, the latter is oxidized and its signal measured via CV. A linear response to the Salmonella species is obtained in the 104 to 109 cfu · mL−1 concentration range, and the detection limits are 3.0 × 103 cfu · mL−1 for both species (at an SNR of 3). This assay is sensitive, highly specific, acceptably accurate and reproducible. Given its low detection limit, it represents a promising tool for the detection of S. pullorum, S. gallinarum, and - conceivably - of other food-borne pathogens by exchanging the antibody. (author)

  6. Ionic liquid-assisted bidirectional regulation strategy for carbon quantum dots (CQDs)/Bi4O5I2 nanomaterials and enhanced photocatalytic properties.

    Science.gov (United States)

    Ji, Mengxia; Xia, Jiexiang; Di, Jun; Wang, Bin; Yin, Sheng; Xu, Li; Zhao, Junze; Li, Huaming

    2016-09-15

    In this study, novel visible-light-driven carbon quantum dots (CQDs)/Bi4O5I2 material has been prepared via a reactable ionic liquid 1-hexyl-3-methylimidazolium iodide ([Hmim]I) assisted bidirectional regulation solvothermal method. This is the first time for the preparation of CQDs/Bi4O5I2 material with halogen and CQDs bidirectional regulation at the same time. With CQDs modified on the surface of Bi4O5I2, fast transfer of photogenerated charges and low recombination of photo-induced electron-hole pairs facilitated the enhancement of photodegradation activity. At the same time, the introduction of CQDs made the electrons occupied in high-energy potential on the conduction band of Bi4O5I2 transfer to the reaction center CQDs and the molecular oxygen can be thus activated. The enhanced mechanisms for the active species (holes, hydroxyl and superoxide radicals) during the photocatalytic reaction under visible irradiation were analyzed using DRS analysis, electron spin resonance (ESR) technique and free radicals trapping experiments. PMID:27318012

  7. Enhanced direct electron transfer reactivity of hemoglobin in cationic gemini surfactant-room temperature ionic liquid composite film on glassy carbon electrodes

    International Nuclear Information System (INIS)

    A novel composite film comprising cationic gemini surfactant butyl-α,ω-bis(dimethylcetylammonium bromide) (C16H33N(CH3)2-C4H8-N(CH3)2C16H33, C16-C4-C16) and ionic liquid 1-octyl-3-methylimidazolium hexafluorophate (OMIMPF6) has been prepared. The composite film shows good biocompatibility and it can promote the direct electron transfer between hemoglobin (Hb) and glassy carbon (GC) electrode. On the C16-C4-C16 (dissolved in ethanol)-OMIMPF6 film coated GC electrode, the immobilized Hb can exhibit a pair of well-defined, quasi-reversible and stable redox peaks with a formal potential of -0.317 V (vs SCE) in 0.10 M pH 7 phosphate buffer solutions. The electron transfer coefficient (α) of Hb is calculated to be 0.44 and the heterogeneous electron transfer rate constant is 6.08 s-1. With the length of alkyl chains of gemini surfactant increasing and the ethanol concentration rising, the redox peaks of the resulting electrode C16-C4-C16-OMIMPF6-Hb/GC become bigger. The electrode presents good electrocatalytic response to peroxide hydrogen. The kinetic parameters Imax and km for the catalytic reaction are estimated. In addition, UV-vis spectra and reflectance absorption infrared spectra demonstrate that the Hb immobilized in the C16-C4-C16-OMIMPF6 film almost retains the structure of native Hb

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

    International Nuclear Information System (INIS)

    The stabilization energies for the formation (Eform) of 11 ion pairs of protic and aprotic ionic liquids were studied by MP2/6-311G** level ab initio calculations to elucidate the difference between the interactions of ions in protic ionic liquids and those in aprotic ionic liquids. The interactions in the ion pairs of protic ionic liquids (diethylmethylammonium [dema] and dimethylpropylammonium [dmpa] based ionic liquids) are stronger than those of aprotic ionic liquids (ethyltrimethylammonium [etma] based ionic liquids). The Eform for the [dema][CF3SO3] and [dmpa][CF3SO3] complexes (−95.6 and −96.4 kcal/mol, respectively) are significantly larger (more negative) than that for the [etma][CF3SO3] complex (−81.0 kcal/mol). The same trend was observed for the calculations of ion pairs of the three cations with the Cl−, BF4−, TFSA− anions. The anion has contact with the N–H bond of the dema+ or dmpa+ cations in the most stable geometries of the dema+ and dmpa+ complexes. The optimized geometries, in which the anions locate on the counter side of the cations, are 11.0–18.0 kcal/mol less stable, which shows that the interactions in the ions pairs of protic ionic liquids have strong directionality. The Eform for the less stable geometries for the dema+ and dmpa+ complexes are close to those for the most stable etma+ complexes. The electrostatic interaction, which is the major source of the attraction in the ion pairs, is responsible for the directionality of the interactions and determining the magnitude of the interaction energy. Molecular dynamic simulations of the [dema][TFSA] and [dmpa][TFSA] ionic liquids show that the N–H bonds of the cations have contact with the negatively charged (oxygen and nitrogen) atoms of TFSA− anion, while the strong directionality of the interactions was not suggested from the simulation of the [etma][CF3SO3] ionic liquid

  9. Ionic liquid integrated multiwalled carbon nanotube in a poly(vinylidene fluoride) matrix: formation of a piezoelectric β-polymorph with significant reinforcement and conductivity improvement.

    Science.gov (United States)

    Mandal, Amit; Nandi, Arun K

    2013-02-01

    Multiwalled carbon nanotubes (MWNTs) are functionalized covalently with ionic liquid (IL, 3-aminoethyl imidazolium bromide) which helps good dispersion of IL-functionalized MWNTs (MWNT-IL) in the poly(vinylidene fluoride) (PVDF) matrix. Analysis of transmission electron microscopy (TEM) micrographs suggests ∼10 nm coating thickness of MWNTs by ILs, and the covalent linkage of ILs with MWNTs is confirmed from FT-IR and Raman spectra. PVDF nanocomposites with full β-polymorphic (piezoelectric) form are prepared using MWNT-IL by both the solvent cast and melt-blending methods. The FE-SEM and TEM micrographs indicate that IL-bound MWNTs are homogeneously dispersed within the PVDF matrix. Increasing MWNT-IL concentration in the composites results in increased β polymorph formation with a concomitant decrease of the α polymorph, and a 100% β polymorph formation occurs for 1 wt % MWNT-IL in both the fabrication conditions. A differential scanning calorimetry (DSC) study shows that the MWNT-ILs are an efficient nucleating agent for PVDF crystallization preferentially nucleating the β form due to its dipolar interactions with PVDF. The glass transition temperature (T(g)) gradually increases with an increase in MWNT-IL concentration, and the storage modulus (G') of the composites increases significantly, showing a maximum increase of 101.3% for 0.5 wt % MWNT-IL. The Young's modulus increases with MWNT-IL concentration, and analysis of the data using the Halpin-Tsai equation suggests that at low concentration they adopt an orientation parallel to the film surface; however, at higher MWNT-IL concentration it is randomly oriented. The tensile strength also increases with an increase in MWNT-IL concentration, and both the Young's modulus and the tensile strength of solvent cast films are lower than melt-blended samples. The elongation at break in the solvent cast samples shows a maximum, but in melt-blended samples it decreases continuously with increasing MWNT

  10. Ionic liquids as a novel solvent for lanthanide extraction.

    Science.gov (United States)

    Nakashima, Kazunori; Kubota, Fukiko; Maruyama, Tatsuo; Goto, Masahiro

    2003-08-01

    Octyl(phenyl)-N,N-diisobutylcarbamoylmethyl phosphine oxide (CMPO) dissolved in an ionic liquids, 1-butyl-3-methyl-imidazolium hexafluorophosphate, greatly enhances extractability and selectivity of lanthanide cations compared to that dissolved in conventional organic solvents; further, the recovery of lanthanides extracted into ionic liquids can be accomplished using several stripping solutions containing complexing agents. The possibility of utilizing ionic liquids as novel separation media in an industrial liquid-liquid extraction process was demonstrated. PMID:12945658

  11. Ionic liquids for enzymatic sensing

    OpenAIRE

    Fraser, Kevin J.; Byrne, Robert; Benito-Lopez, Fernando; Warren, Susan; Dempsey, Eithne; Diamond, Dermot

    2011-01-01

    The key challenges currently faced in lab-on-a-chip biochemical sensor developments are device reliability and power consumption. The major issues faced in terms of device reliability are liquid handling over extended periods of time, as the micro-dimensioned fluidic channels are prone to blockage, and unreliable micro pumps/valves. The overall aim of this proposal is to develop a biocompatible molecular sensor that will address these key issues which are holding back biocompatible sensors te...

  12. Antimicrobial Ionic Liquids with Fumarate Anion

    Directory of Open Access Journals (Sweden)

    Biyan He

    2013-01-01

    Full Text Available The shortage of new antimicrobial drugs and increasing resistance of microbe to antimicrobial agents have been of some concern. The formulation studies of new antibacterial and antifungal agents have been an active research field. Ionic liquids are known as designed liquids with controllable physical/chemical/biological properties and specific functions, which have been attracting considerable interest over recent years. However, no attention has been made towards the preparation of ionic liquids with antimicrobial activities. In this paper, a new class of ionic liquids (ILs with fumarate anion was synthesized by neutralization of aqueous 1-butyl-3-methylimidazolium hydroxide with equimolar monoester fumarate and characterized using NMR and thermal gravimetric analysis. The ILs are soluble in water and polar organic solvents and also soluble in the common ILs. The antimicrobial activities of the ILs are more active than commercially available potassium sorbate and are greatly affected by the alkyl chain length. The significant antimicrobial properties observed in this research suggest that the ILs may have potential applications in the modern biotechnology.

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

    Directory of Open Access Journals (Sweden)

    Scott T. Handy

    2011-07-01

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

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

    Science.gov (United States)

    Lima, Thamires A.; Paschoal, Vitor H.; Faria, Luiz F. O.; Ribeiro, Mauro C. C.; Giles, Carlos

    2016-06-01

    X-ray scattering experiments at room temperature were performed for the ionic liquids n-butyl-trimethylammonium bis(trifluoromethanesulfonyl)imide, [N1114][NTf2], and methyl-tributylammonium bis(trifluoromethanesulfonyl)imide, [N1444][NTf2]. The peak in the diffraction data characteristic of charge ordering in [N1444][NTf2] is shifted to longer distances in comparison to [N1114][NTf2], but the peak characteristic of short-range correlations is shifted in [N1444][NTf2] to shorter distances. Molecular dynamics (MD) simulations were performed for these ionic liquids using force fields available from the literature, although with new sets of partial charges for [N1114]+ and [N1444]+ proposed in this work. The shifting of charge and adjacency peaks to opposite directions in these ionic liquids was found in the static structure factor, S(k), calculated by MD simulations. Despite differences in cation sizes, the MD simulations unravel that anions are allowed as close to [N1444]+ as to [N1114]+ because anions are located in between the angle formed by the butyl chains. The more asymmetric molecular structure of the [N1114]+ cation implies differences in partial structure factors calculated for atoms belonging to polar or non-polar parts of [N1114][NTf2], whereas polar and non-polar structure factors are essentially the same in [N1444][NTf2]. Results of this work shed light on controversies in the literature on the liquid structure of tetraalkylammonium based ionic liquids.

  15. Furfural production using ionic liquids: A review.

    Science.gov (United States)

    Peleteiro, Susana; Rivas, Sandra; Alonso, José Luis; Santos, Valentín; Parajó, Juan Carlos

    2016-02-01

    Furfural, a platform chemical with a bright future, is commercially obtained by acidic processing of xylan-containing biomass in aqueous media. Ionic liquids (ILs) can be employed in processed for furfural manufacture as additives, as catalysts and/or as reaction media. Depending on the IL utilized, externally added catalysts (usually, Lewis acids, Brönsted acids and/or solid acid catalysts) can be necessary to achieve high reaction yields. Oppositely, acidic ionic liquids (AILs) can perform as both solvents and catalysts, enabling the direct conversion of suitable substrates (pentoses, pentosans or xylan-containing biomass) into furfural. Operating in IL-containing media, the furfural yields can be improved when the product is continuously removed along the reaction (for example, by stripping or extraction), to avoid unwanted side-reactions leading to furfural consumption. These topics are reviewed, as well as the major challenges involved in the large scale utilization of ILs for furfural production. PMID:26708486

  16. Dynamics of Ion Transport in Ionic Liquids.

    Science.gov (United States)

    Lee, Alpha A; Kondrat, Svyatoslav; Vella, Dominic; Goriely, Alain

    2015-09-01

    A gap in understanding the link between continuum theories of ion transport in ionic liquids and the underlying microscopic dynamics has hindered the development of frameworks for transport phenomena in these concentrated electrolytes. Here, we construct a continuum theory for ion transport in ionic liquids by coarse graining a simple exclusion process of interacting particles on a lattice. The resulting dynamical equations can be written as a gradient flow with a mobility matrix that vanishes at high densities. This form of the mobility matrix gives rise to a charging behavior that is different to the one known for electrolytic solutions, but which agrees qualitatively with the phenomenology observed in experiments and simulations. PMID:26382685

  17. Interfacial properties of charge asymmetric ionic liquids

    OpenAIRE

    Alejandre, Jose; Bresme, Fernando; Gonzalez-Melchor, Minerva

    2009-01-01

    We report molecular dynamics simulations of the coexistence and interfacial properties of ionic liquids as a function of cation/anion, (z$_+$ : z$_-$) = (2:-1), (4:-1), charge asymmetry. Our results correct previous computations of the coexistence curve of (2:-1) charge asymmetric systems, obtained via the fine-lattice discretization method. In agreement with previous computations we report a reduction in the critical temperature and an increase in the critical density with charge asymmetry. ...

  18. Supported ionic liquids fundamentals and applications

    CERN Document Server

    Fehrmann, Rasmus; Haumann, Marco

    2013-01-01

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

  19. Interfacial properties of charge asymmetric ionic liquids

    OpenAIRE

    2009-01-01

    Abstract We report molecular dynamics simulations of the coexistence and interfacial properties of ionic liquids as a function of cation/anion, (z$_+$ : z$_-$) = (2:-1), (4:-1), charge asymmetry. Our results correct previous computations of the coexistence curve of (2:-1) charge asymmetric systems, obtained via the fine-lattice discretization method. In agreement with previous computations we report a reduction in the critical temperature and an increase in the critical density wit...

  20. The friction and wear characteristics and lubrication mechanism of imidazole phosphate ionic liquid

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Several imidazole phosphate ionic liquids with varying carbon chain length have been synthesized at room temperature.Corrosion characteristics and tribological properties of these synthesized ionic liquids were studied using four-ball friction and wear testing machine.Its lubrication mechanism was also investigated by means of electron microscopy and X-ray photoelectron spectroscopy.The ex-perimental results showed that no corrosion was generated when the imidazole phosphate ionic liquid was applied to steel-steel pair.Meanwhile,the imidazole phosphate showed excellent anti-wear and lubricating performances,its frictional performance was related to the polarity of ionic liquids.It is suggested that the ionic liquids react with friction surface to form a protective film of iron phosphate and result in reduction in friction and wear.

  1. The friction and wear characteristics and lubrication mechanism of imidazole phosphate ionic liquid

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lin; FENG DaPeng; XU Bin; LIU XuQing; LIU WeiMin

    2009-01-01

    Several imidazole phosphate ionic liquids with varying carbon chain length have been synthesized at room temperature. Corrosion characteristics and tribological properties of these synthesized ionic liquids were studied using four-ball friction and wear testing machine. Its lubrication mechanism was also investigated by means of electron microscopy and X-ray photoelectron spectroscopy. The ex-perimental results showed that no corrosion was generated when the imidazole phosphate ionic liquid was applied to steel-steel pair. Meanwhile, the imidazole phosphate showed excellent anti-wear and lubricating performances, its frictional performance was related to the polarity of ionic liquids. It is suggested that the ionic liquids react with friction surface to form a protective film of iron phosphate and result in reduction in friction and wear.

  2. Ionic liquids and their solid-state analogues as materials for energy generation and storage

    Science.gov (United States)

    Macfarlane, Douglas R.; Forsyth, Maria; Howlett, Patrick C.; Kar, Mega; Passerini, Stefano; Pringle, Jennifer M.; Ohno, Hiroyuki; Watanabe, Masayoshi; Yan, Feng; Zheng, Wenjun; Zhang, Shiguo; Zhang, Jie

    2016-02-01

    Salts that are liquid at room temperature, now commonly called ionic liquids, have been known for more than 100 years; however, their unique properties have only come to light in the past two decades. In this Review, we examine recent work in which the properties of ionic liquids have enabled important advances to be made in sustainable energy generation and storage. We discuss the use of ionic liquids as media for synthesis of electromaterials, for example, in the preparation of doped carbons, conducting polymers and intercalation electrode materials. Focusing on their intrinsic ionic conductivity, we examine recent reports of ionic liquids used as electrolytes in emerging high-energy-density and low-cost batteries, including Li-ion, Li-O2, Li-S, Na-ion and Al-ion batteries. Similar developments in electrolyte applications in dye-sensitized solar cells, thermo-electrochemical cells, double-layer capacitors and CO2 reduction are also discussed.

  3. Use of Ionic Liquids in Recycle of Palladium Catalysts for Synthesis of Polyketone

    Institute of Scientific and Technical Information of China (English)

    TIAN Jing; GUO Jintang; ZHANG Xuemei; ZHANG Xin; XU Yongshen

    2008-01-01

    Room temperature ionic liquids as solvents for palladium-catalyzed copolymerization of carbon monoxide and styrene were prepared by reaction of aqueous lead tetrafluoroborate with correspond-ing chloride or bromide salts. The recyclability of palladium composite catalyst in various ionic liquids was investigated.[Pd(bipy)2][BF4]2 showed a lower catalytic activity than [Pd(bipy)2][PF6]2 in similar conditions, although the catalytic activity of each composite catalyst in ionic liquids still existed after 4 successive recycles. It was shown the catalytic activity of palladium composite catalyst was higher than that of the catalyst formed in situ from palladium acetate, 2,2'-bipyridyl, and HA (A=PF6-, BF4-) in ionic liquids. The effects of volume of ionic liquids, reaction time, and the dosage of benzoquinone on the copolymerization were also studied.

  4. Understanding SO2 Capture by Ionic Liquids.

    Science.gov (United States)

    Mondal, Anirban; Balasubramanian, Sundaram

    2016-05-19

    Ionic liquids have generated interest for efficient SO2 absorption due to their low vapor pressure and versatility. In this work, a systematic investigation of the structure, thermodynamics, and dynamics of SO2 absorption by ionic liquids has been carried out through quantum chemical calculations and molecular dynamics (MD) simulations. MP2 level calculations of several ion pairs complexed with SO2 reveal its preferential interaction with the anion. Results of condensed phase MD simulations of SO2-IL mixtures manifested the essential role of both cations and anions in the solvation of SO2, where the solute is surrounded by the "cage" formed by the cations (primarily its alkyl tail) through dispersion interactions. These structural effects of gas absorption are substantiated by calculated Gibbs free energy of solvation; the dissolution is demonstrated to be enthalpy driven. The entropic loss of SO2 absorption in ionic liquids with a larger anion such as [NTf2](-) has been quantified and has been attributed to the conformational restriction of the anion imposed by its interaction with SO2. SO2 loading IL decreases its shear viscosity and enhances the electrical conductivity. This systematic study provides a molecular level understanding which can aid the design of task-specific ILs as electrolytes for efficient SO2 absorption. PMID:27119562

  5. Periodicity and map for discovery of new ionic liquids

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    There is virtually no limit in the number of ionic liquids. How to select proper ones or discover new ones with desirable properties in such a large pool of ionic liquids? It has become a bottleneck in the researches and applications of ionic liquids. Mendeleev's periodic law states that the properties of the elements vary periodically. Whether the similar regularity exists among ionic or molecular fragments of compounds is an interesting topic. In this work, we attempted to establish a periodicity and draw a "map" of ionic liquids for providing definite guidance to discover, design, and select the proper ionic liquids rather than trial-and-error. If a complete regularity of the system of ionic liquids can be finally established in the future, we are near an epoch in understanding the existing differences and the reasons for the similarity of the ions or molecular fragments.

  6. Assay of carbon nanoparticles in liquids.

    Science.gov (United States)

    Nawi, Yehuda; Sasson, Yoel; Dolgin, Bella

    2016-04-01

    The critical assay of carbon black concentration suffers from the lack of available methods, especially in-situ methods suitable for nanoparticles. We propose a useful tool for monitoring carbon nanoparticles concentration in liquids by means of RGB imaging, fluorescence and conductivity measurements. In this study carbon black particles of 25-75nm size were dispersed within two types of "green" liquids (1-butyl-3-methyl imidazolium based ionic liquids and glycerol) and the effect of carbon nanoparticles concentration on the liquids properties was measured. The conductivity of all the liquids increased with carbon concentration, while the slope of the curve was liquid dependent. The fluorescence intensity of ionic liquids decreased dramatically even when a small amount of carbon was added, while water-containing ionic liquids had a more moderate behavior. Glycerol has no native fluorescence, therefore, a known tracer present in soot (dibenzothiophene), having a characteristic fluorescence monitored by synchronous scan mode, was used. The carbon black effect on RGB imaging shows a linear dependence, while the red counts decreases with contamination. The proposed methods are simple and low-cost but nonetheless sensitive. PMID:26780588

  7. Lipid Bilayer Formation in Aqueous Solutions of Ionic Liquids

    OpenAIRE

    Young, Taylor Tront

    2012-01-01

    The formation of lipid bilayer membranes between droplets of ionic liquid is presented as a means of forming functional bimolecular networks for use in sensor applications. Ionic liquids are salts that have a number of useful properties, such as low melting points making them liquid at room temperature and exceedingly low vapor pressure. Ionic liquids have seen recent popularity as environmentally friendly industrial solvent alternatives. Our research demonstrates that it is possible to cons...

  8. Enhanced direct electron transfer reactivity of hemoglobin in cationic gemini surfactant-room temperature ionic liquid composite film on glassy carbon electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Li Jiangwen; Liu Lihong; Yan Rui; Xiao Mengying; Liu Liqin [Department of Chemistry, Wuhan University, Wuhan 430072 (China); Zhao Faqiong [Department of Chemistry, Wuhan University, Wuhan 430072 (China)], E-mail: zhaofq@chem.edu.cn; Zeng Baizhao [Department of Chemistry, Wuhan University, Wuhan 430072 (China)

    2008-05-20

    A novel composite film comprising cationic gemini surfactant butyl-{alpha},{omega}-bis(dimethylcetylammonium bromide) (C{sub 16}H{sub 33}N(CH{sub 3}){sub 2}-C{sub 4}H{sub 8}-N(CH{sub 3}){sub 2}C{sub 16}H{sub 33}, C{sub 16}-C{sub 4}-C{sub 16}) and ionic liquid 1-octyl-3-methylimidazolium hexafluorophate (OMIMPF{sub 6}) has been prepared. The composite film shows good biocompatibility and it can promote the direct electron transfer between hemoglobin (Hb) and glassy carbon (GC) electrode. On the C{sub 16}-C{sub 4}-C{sub 16} (dissolved in ethanol)-OMIMPF{sub 6} film coated GC electrode, the immobilized Hb can exhibit a pair of well-defined, quasi-reversible and stable redox peaks with a formal potential of -0.317 V (vs SCE) in 0.10 M pH 7 phosphate buffer solutions. The electron transfer coefficient ({alpha}) of Hb is calculated to be 0.44 and the heterogeneous electron transfer rate constant is 6.08 s{sup -1}. With the length of alkyl chains of gemini surfactant increasing and the ethanol concentration rising, the redox peaks of the resulting electrode C{sub 16}-C{sub 4}-C{sub 16}-OMIMPF{sub 6}-Hb/GC become bigger. The electrode presents good electrocatalytic response to peroxide hydrogen. The kinetic parameters I{sub max} and k{sub m} for the catalytic reaction are estimated. In addition, UV-vis spectra and reflectance absorption infrared spectra demonstrate that the Hb immobilized in the C{sub 16}-C{sub 4}-C{sub 16}-OMIMPF{sub 6} film almost retains the structure of native Hb.

  9. Electrochemical sensors for the simultaneous determination of zinc, cadmium and lead using a Nafion/ionic liquid/graphene composite modified screen-printed carbon electrode.

    Science.gov (United States)

    Chaiyo, Sudkate; Mehmeti, Eda; Žagar, Kristina; Siangproh, Weena; Chailapakul, Orawon; Kalcher, Kurt

    2016-04-28

    A simple, low cost, and highly sensitive electrochemical sensor, based on a Nafion/ionic liquid/graphene composite modified screen-printed carbon electrode (N/IL/G/SPCE) was developed to determine zinc (Zn(II)), cadmium (Cd(II)), and lead (Pb(II)) simultaneously. This disposable electrode shows excellent conductivity and fast electron transfer kinetics. By in situ plating with a bismuth film (BiF), the developed electrode exhibited well-defined and separate peaks for Zn(II), Cd(II), and Pb(II) by square wave anodic stripping voltammetry (SWASV). Analytical characteristics of the BiF/N/IL/G/SPCE were explored with calibration curves which were found to be linear for Zn(II), Cd(II), and Pb(II) concentrations over the range from 0.1 to 100.0 ng L(-1). With an accumulation period of 120 s detection limits of 0.09 ng mL(-1), 0.06 ng L(-1) and 0.08 ng L(-1) were obtained for Zn(II), Cd(II) and Pb(II), respectively using the BiF/N/IL/G/SPCE sensor, calculated as 3σ value of the blank. In addition, the developed electrode displayed a good repeatability and reproducibility. The interference from other common ions associated with Zn(II), Cd(II) and Pb(II) detection could be effectively avoided. Finally, the proposed analytical procedure was applied to detect the trace metal ions in drinking water samples with satisfactory results which demonstrates the suitability of the BiF/N/IL/G/SPCE to detect heavy metals in water samples and the results agreed well with those obtained by inductively coupled plasma mass spectrometry. PMID:27046207

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

    Science.gov (United States)

    Li, Zaiwei; Tang, Yongchun; Cheng; Jihong

    2009-11-10

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

  11. Importance of liquid fragility for energy applications of ionic liquids

    Science.gov (United States)

    Sippel, P.; Lunkenheimer, P.; Krohns, S.; Thoms, E.; Loidl, A.

    2015-09-01

    Ionic liquids (ILs) are salts that are liquid close to room temperature. Their possible applications are numerous, e.g., as solvents for green chemistry, in various electrochemical devices, and even for such “exotic” purposes as spinning-liquid mirrors for lunar telescopes. Here we concentrate on their use for new advancements in energy-storage and -conversion devices: Batteries, supercapacitors or fuel cells using ILs as electrolytes could be important building blocks for the sustainable energy supply of tomorrow. Interestingly, ILs show glassy freezing and the universal, but until now only poorly understood dynamic properties of glassy matter, dominate many of their physical properties. We show that the conductivity of ILs, an essential figure of merit for any electrochemical application, depends in a systematic way not only on their glass temperature but also on the so-called fragility, characterizing the non-canonical super-Arrhenius temperature dependence of their ionic mobility.

  12. Reduction of Metal Oxide to Metal using Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Ramana Reddy

    2012-04-12

    A novel pathway for the high efficiency production of metal from metal oxide means of electrolysis in ionic liquids at low temperature was investigated. The main emphasis was to eliminate the use of carbon and high temperature application in the reduction of metal oxides to metals. The emphasis of this research was to produce metals such as Zn, and Pb that are normally produced by the application of very high temperatures. The reduction of zinc oxide to zinc and lead oxide to lead were investigated. This study involved three steps in accomplishing the final goal of reduction of metal oxide to metal using ionic liquids: 1) Dissolution of metal oxide in an ionic liquid, 2) Determination of reduction potential using cyclic voltammetry (CV) and 3) Reduction of the dissolved metal oxide. Ionic liquids provide additional advantage by offering a wide potential range for the deposition. In each and every step of the process, more than one process variable has been examined. Experimental results for electrochemical extraction of Zn from ZnO and Pb from PbO using eutectic mixtures of Urea ((NH2)2CO) and Choline chloride (HOC2H4N(CH3)3+Cl-) or (ChCl) in a molar ratio 2:1, varying voltage and temperatures were carried out. Fourier Transform Infra-Red (FTIR) spectroscopy studies of ionic liquids with and without metal oxide additions were conducted. FTIR and induction coupled plasma spectroscopy (ICPS) was used in the characterization of the metal oxide dissolved ionic liquid. Electrochemical experiments were conducted using EG&G potentiostat/galvanostat with three electrode cell systems. Cyclic voltammetry was used in the determination of reduction potentials for the deposition of metals. Chronoamperometric experiments were carried out in the potential range of -0.6V to -1.9V for lead and -1.4V to -1.9V for zinc. The deposits were characterized using XRD and SEM-EDS for phase, morphological and elemental analysis. The results showed that pure metal was deposited on the cathode

  13. Evaporation from an ionic liquid emulsion.

    Science.gov (United States)

    Friberg, Stig E

    2007-03-15

    The conditions during evaporation in a liquid crystal-in-ionic liquid microemulsion (LC/microEm) were estimated using the phase diagram of the system. The equations for selected tie lines were established and the coordinates calculated for the sites, at which the evaporation lines crossed the tie lines. These values combined with the coordinates for the phases connecting the tie lines were used to calculate the amounts and the composition of the fractions of the two phases present in the emulsion during the evaporation. One of the emulsion phases was a lamellar liquid crystal and high energy emulsification would lead to the liquid crystal being disrupted to form vesicles. Such a system tenders a unique opportunity to study the interaction between vesicles and normal micelles, which gradually change to inverse micelles over bi-continuous structures. The amount of vesicles in the liquid phase versus the fraction liquid crystal was calculated for two extreme cases of vesicle core size and shell thickness. The limit of evaporation while retaining the vesicle structure was calculated for emulsions of different original compositions assuming the minimum continuous liquid phase to be 50% of the emulsion. PMID:17207810

  14. Magnetic microemulsions based on magnetic ionic liquids.

    Science.gov (United States)

    Klee, Andreas; Prevost, Sylvain; Kunz, Werner; Schweins, Ralf; Kiefer, Klaus; Gradzielski, Michael

    2012-11-28

    Microemulsions with magnetic properties were formed by employing a magnetic room temperature ionic liquid (MRTIL) as polar phase, cyclohexane as oil, and an appropriate mixture of ionic surfactant and decanol as a cosurfactant. By means of small-angle neutron scattering (SANS) and electric conductivity the microemulsion structure could be confirmed, where the classical structural sequence of oil-continuous-bicontinuous-polar phase continuous is observed with increasing ratio [polar phase]/[oil]. Accordingly a maximum of the structural size is observed at about equal volumes of oil and MRTIL contained. Therefore this system is structurally the same as normal microemulsions but with the magnetic properties added to it by the incorporation into the systems formulation. PMID:23060241

  15. Bottom-up electrochemical preparation of solid-state carbon nanodots directly from nitriles/ionic liquids using carbon-free electrodes and the applications in specific ferric ion detection and cell imaging.

    Science.gov (United States)

    Niu, Fushuang; Xu, Yuanhong; Liu, Mengli; Sun, Jing; Guo, Pengran; Liu, Jingquan

    2016-03-14

    Carbon nanodots (C-dots), a new type of potential alternative to conventional semiconductor quantum dots, have attracted numerous attentions in various applications including bio-chemical sensing, cell imaging, etc., due to their chemical inertness, low toxicity and flexible functionalization. Various methods including electrochemical (EC) methods have been reported for the synthesis of C-dots. However, complex procedures and/or carbon source-containing electrodes are often required. Herein, solid-state C-dots were simply prepared by bottom-up EC carbonization of nitriles (e.g. acetonitrile) in the presence of an ionic liquid [e.g. 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6)], using carbon-free electrodes. Due to the positive charges of BMIM(+) on the C-dots, the final products presented in a precipitate form on the cathode, and the unreacted nitriles and BMIMPF6 can be easily removed by simple vacuum filtration. The as-prepared solid-state C-dots can be well dispersed in an aqueous medium with excellent photoluminescence properties. The average size of the C-dots was found to be 3.02 ± 0.12 nm as evidenced by transmission electron microscopy. Other techniques such as UV-vis spectroscopy, fluorescence spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy were applied for the characterization of the C-dots and to analyze the possible generation mechanism. These C-dots have been successfully applied in efficient cell imaging and specific ferric ion detection. PMID:26891173

  16. Progress in Separation of Gases by Permeation and Liquids by Pervaporation Using Ionic Liquids: A Review

    OpenAIRE

    Kárászová, M. (Magda); Kačírková, M. (Marie); Friess, K.; Izák, P. (Pavel)

    2014-01-01

    The effective separation of gases and liquids by membranes containing ionic liquids actually belongs to one of the challenging topics in membrane community. During last decade, a plenty of new kinds of ionic liquids (IL), their combinations, different types of polymerized ionic liquids and polymer–IL composite membranes were developed and tested. This review summarizes the most important achievements and findings connected with the ionic liquid based membranes research and tries to answer h...

  17. A sol-gel derived pH-responsive bovine serum albumin molecularly imprinted poly(ionic liquids) on the surface of multiwall carbon nanotubes.

    Science.gov (United States)

    Liu, Mingming; Pi, Jiangyan; Wang, Xiaojie; Huang, Rong; Du, Yamei; Yu, Xiaoyang; Tan, Wenfeng; Liu, Fan; Shea, Kenneth J

    2016-08-17

    A pH-responsive surface molecularly imprinted poly(ionic liquids) (MIPILs) was prepared on the surface of multiwall carbon nanotubes (MWCNTs) by a sol-gel technique. The material was synthesized using a 3-aminopropyl triethoxysilane modified multiwall carbon nanotube (MWCNT-APTES) as the substrate, bovine serum albumin (BSA) as the template molecule, an alkoxy-functionalized IL 1-(3-trimethoxysilyl propyl)-3-methyl imidazolium chloride ([TMSPMIM]Cl) as both the functional monomer and the sol-gel catalyst, and tetraethoxysilane (TEOS) as the crosslinking agent. The molecular interaction between BSA and [TMSPMIM]Cl was quantitatively evaluated by UV-vis spectroscopy prior to polymerization so as to identify an optimal template/monomer ratio and the most suitable pH value for the preparation of the MWCNTs@BSA-MIPILs. This strategy was found to be effective to overcome the problems of trial-and-error protocol in molecular imprinting. The optimum synthesis conditions were as follows: template/monomer ratio 7:20, crosslinking agent content 2.0-2.5 mL, temperature 4 °C and pH 8.9 Tris-HCl buffer. The influence of incubation pH on adsorption was also studied. The result showed that the imprinting effect and selectivity improved significantly with increasing incubation pH from 7.7 to 9.9. This is mainly because the non-specific binding from electrostatic and hydrogen bonding interactions decreased greatly with the increase of pH value, which made the specific binding affinity from shape selectivity strengthened instead. The polymers synthesized under the optimal conditions were then characterized by BET surface area measurement, FTIR, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The adsorption capacity, imprinting effect, selective recognition and reusability were also evaluated. The as-prepared MWCNTs@BSA-MIPILs were also found to have a number of advantages including high surface area (134.2 m(2) g(-1)), high adsorption capacity (55.52

  18. Supported ionic liquids: versatile reaction and separation media

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Haumann, Marco; Wasserscheid, Peter

    The latest developments in supported ionic liquid phase (SILP) systems for catalysis and separation technology are surveyed. The SILP concept combines the advantages of homogeneous catalysis with heterogeneous process technology, and a variety of reactions have been studied where supported ionic...... liquid catalysts proved to be more active and selective than common systems. In separation applications the use of supported ionic liquids can facilitate selective transport of substrates across membranes....

  19. Ionic Liquid assisted Synthesis of Zeolite-TON

    OpenAIRE

    Tian, Yuyang; McPherson, Matthew Joseph; Wheatley, Paul Stewart; Morris, Russell Edward

    2014-01-01

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

  20. Soft ionization of thermally evaporated hypergolic ionic liquid aerosols

    OpenAIRE

    Koh, Christine J.

    2013-01-01

    Isolated ion pairs of a conventional ionic liquid, 1-Ethyl-3-Methyl-Imidazolium Bis(trifluoromethylsulfonyl)imide ([Emim+][Tf2N?]), and a reactive hypergolic ionic liquid, 1-Butyl-3-Methyl-Imidazolium Dicyanamide ([Bmim+][Dca?]), are generated by vaporizing ionic liquid submicron aerosol particles for the first time; the vaporized species are investigated by dissociative ionization with tunable vacuum ultraviolet (VUV) light, exhibiting clear intact cations, Emim+ and Bmim+, presumably origi...

  1. Silica–enzyme–ionic liquid composites for improved enzymatic activity

    OpenAIRE

    Katsuya Kato; Yuki Kawachi; Hitomi Nakamura

    2014-01-01

    Trypsin and pepsin enzyme-catalyzed precipitation of silica, synthesized by sol–gel chemistry in an ionic liquid, produces a composite material that demonstrates high enzymatic activity. This study investigates the structural properties of this silica–enzyme–ionic liquid composite material that allows for the retention of enzyme hydrolysis and condensation activity. The composite was prepared from a mixture of organo-functionalized triethoxysilane and tetraethoxysilane in an ionic liquid via ...

  2. Ion Transport in Nanostructured Block Copolymer/Ionic Liquid Membranes

    OpenAIRE

    Hoarfrost, Megan Lane

    2012-01-01

    Incorporating an ionic liquid into one block copolymer microphase provides a platform for combining the outstanding electrochemical properties of ionic liquids with a number of favorable attributes provided by block copolymers. In particular, block copolymers thermodynamically self-assemble into well-ordered nanostructures, which can be engineered to provide a durable mechanical scaffold and template the ionic liquid into continuous ion-conducting nanochannels. Understanding how the additio...

  3. Electrospun nanosized cellulose fibers using ionic liquids at room temperature

    OpenAIRE

    Freire, Mara G.; Teles, Ana Rita R.; Ferreira, Rute A. S.; Carlos, Luís D.; José A. Lopes-da-Silva; Coutinho, João A. P.

    2011-01-01

    Aiming at replacing the noxious solvents commonly employed, ionic-liquid-based solvents have been recently explored as novel non-volatile and non-flammable media for the electrospinning of polymers. In this work, nanosized and biodegradable cellulose fibers were obtained by electrospinning at room temperature using a pure ionic liquid or a binary mixture of two selected ionic liquids. The electrospinning of 8 wt% cellulose in 1-ethyl-3-methylimidazolium acetate medium (a low viscosity and roo...

  4. Atmospheric Moisture Content Effects on Ionic Liquid Wettability of Alumina

    OpenAIRE

    Brittle, S.; Samuel, A; W. B. Zimmerman

    2014-01-01

    The contact angles or wettability of 7 Ionic Liquids, on an alumina substrate, have been measured under two different storage conditions. The first using a small amount of moisture content, the second with no moisture content. The contact angle of Ionic Liquid droplets on an alumina substrate were measured using an Attension Theta instrument with automated software. The results show that a small amount of moisture improves the wettability of the Ionic Liquid – alumina system and therefore sub...

  5. INTERACTION OF IONIC LIQUIDS WITH POLYSACCHARIDES

    Directory of Open Access Journals (Sweden)

    Tim Liebert

    2008-05-01

    Full Text Available The use of ionic liquids (ILs in the field of cellulose chemistry opens up a broad variety of new opportunities. Besides the regeneration of the biopolymer to fibers, films, and beads, this new class of cellulose solvents is particularly useful for the homogeneous chemical modification of the polysaccharide. In this review, the potential of ILs as a reaction medium for the homogeneous cellulose functionalization is discussed. It is shown that numerous conversions proceed very efficiently and the ILs may be recycled. But it is also demonstrated that some side reactions have to be considered.

  6. Computationally Efficient Prediction of Ionic Liquid Properties

    DEFF Research Database (Denmark)

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

    2014-01-01

    the ability of RTILs to stay liquid at several hundred degrees Celsius and introduce a straightforward and computationally efficient method for predicting RTIL properties at ambient temperature. RTILs do not alter phase behavior at 600-800 K. Therefore, their properties can be smoothly extrapolated...... down to ambient temperatures. We numerically prove the validity of the proposed concept for density and ionic diffusion of four different RTILs. This simple method enhances the computational efficiency of the existing simulation approaches as applied to RTILs by more than an order of magnitude....

  7. ZnO-ionic liquid nanostructures

    International Nuclear Information System (INIS)

    The mixture of nanostructures derived from the surface interactions and reactivity of ZnO nanoparticles with the room-temperature ionic liquid (IL1) 1-hexyl, 3-methylimidazolium hexafluorophosphate has been studied. Results are discussed on the basis of transmission electron microscopy (TEM) observations, energy dispersive spectroscopy (EDS) analysis, X-ray diffraction (XRD) patterns and X-ray photoelectron spectroscopy (XPS) determinations. Size and morphology changes in ZnO nanoparticles by surface modification with IL1 are observed. ZnF2 crystalline needles due to reaction with the hexafluorophosphate anion are also formed.

  8. Design of Separation Processes with Ionic Liquids

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  9. A Convenient Synthesis of Triflate Anion Ionic Liquids and Their Properties

    Directory of Open Access Journals (Sweden)

    Peter Sartori

    2012-05-01

    Full Text Available A solvent- and halogen-free synthesis of high purity triflate ionic liquids via direct alkylation of organic bases (amines, phosphines or heterocyclic compounds with methyl and ethyl trifluoromethanesulfonate (methyl and ethyl triflate has been developed. Cheap and non-toxic dimethyl and diethyl carbonate serve as source for the methyl and ethyl groups in the preparation of methyl and ethyl triflate by this invented process. The properties of ionic liquids containing the triflate anion are determined and discussed.

  10. Imidazolium ionic liquids as solvents for cerium(IV)-mediated oxidation reactions

    OpenAIRE

    Mehdi, Hasan; Bodor, Andrea; Lantos, Diana; Horváth, István T; De Vos, Dirk; Binnemans, Koen

    2007-01-01

    Use of imidazolium ionic liquids as solvents for organic transformations with tetravalent cerium salts as oxidizing agents was evaluated. Good solubility was found for ammonium hexanitratocerate(IV) (ceric ammonium nitrate, CAN) and cerium(IV) triflate in 1-alkyl-3-methylimidazolium triflate ionic liquids. Oxidation of benzyl alcohol to benzaldehyde in 1-ethyl-3-methylimidazolium triflate was studied by in-situ FTIR spectroscopy and 13C NMR spectroscopy on carbon-13-labeled benzyl alcohol. Ca...

  11. Can ionic liquids avoid third phase formation in solvent extraction?

    International Nuclear Information System (INIS)

    The undesirable third phase is generally encountered in molecular diluent systems at high metal loading concentrations. Since the ionic liquids comprise entirely of ions, the use of an ionic liquid as diluent could stabilize the polar metal-solvate in organic phase and thus could prevent the third phase formation. To confirm this the extraction behavior of Eu(III) from nitric acid medium was studied in a solution of tetra-N,N,N',N'-octyldiglycolamide (TODGA) dissolved in the ionic liquid, 1-methyl-3-octylimidazolium bis(trifluoromethansulfonyl)imide ((C8mim)(NTf2)). Our results confirmed that ionic liquids prevent undesirable third phase formation. (author)

  12. Improving Stability of Gasoline by Using Ionic Liquid Catalyst

    Institute of Scientific and Technical Information of China (English)

    Gao Zhirong; Liu Daosheng; Liao Kejian; Jian Heng

    2003-01-01

    The composition, characteristics and preparation of ionic liquids are presented. The factors influencing the stability of gasoline and the significance of improving gasoline stability are discussed. A novel way to improve the stability of gasoline by using ionic liquid catalyst is developed. The contents of olefin, basic nitrogen and sulfur in gasoline are determined and the optimal experimental conditions for improving gasoline stability are established.The ionic liquid catalyst, which is environmentally friendly, can reduce the olefin content in gasoline, and such process is noted for mild reaction conditions, simple operation, short reaction time, easy recycling of the ionic liquid catalyst and ready separation of products and catalyst.

  13. Lipid extraction from microalgae using a single ionic liquid

    Science.gov (United States)

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

    2013-05-28

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

  14. Room Temperature ionic liquids based on asymmetric ammonium salts

    OpenAIRE

    Shaheen, Sobia

    2013-01-01

    Ionic liquids, ILs, in principle, are salts composed of weakly coordinating ions which are liquids at low temperature (˂100 0C). Room temperature ionic liquids, RTILs are those salts which are liquid even at room temperature. Due to the unique properties, such as large liquid range, negligible vapour pressure, solubility of wide range of materials and potential to be recycled and reused, ILs have become a popular class of solvents and catalysts.This study reports the synthesis of a library of...

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

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Robert L; Damodaran, Krishnan; Luebke, David; Nulwala, Hunaid

    2013-06-01

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

  16. Gold Functionalized Supported Ionic Liquids Catalyst for CO Oxidation

    Directory of Open Access Journals (Sweden)

    Svetlana Ivanova

    2011-11-01

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

  17. Ionic liquid nanostructure enables alcohol self assembly.

    Science.gov (United States)

    Murphy, Thomas; Hayes, Robert; Imberti, Silvia; Warr, Gregory G; Atkin, Rob

    2016-05-14

    Weakly structured solutions are formed from mixtures of one or more amphiphiles and a polar solvent (usually water), and often contain additional organic components. They contain solvophobic aggregates or association structures with incomplete segregation of components, which leads to a poorly defined interfacial region and significant contact between the solvent and aggregated hydrocarbon groups. The length scales, polydispersity, complexity and ill-defined structures in weakly structured solutions makes them difficult to probe experimentally, and obscures understanding of their formation and stability. In this work we probe the nanostructure of homogenous binary mixtures of the ionic liquid (IL) propylammonium nitrate (PAN) and octanol as a function of composition using neutron diffraction and atomistic empirical potential structure refinement (EPSR) fits. These experiments reveal why octanol forms weakly structured aggregates in PAN but not in water, the mechanism by which PAN stabilises the octanol assemblies, and how the aggregate morphologies evolve with octanol concentration. This new understanding provides insight into the general stabilisation mechanisms and structural features of weakly structured mixtures, and reveals new pathways for identifying molecular or ionic liquids that are likely to facilitate aggregation of non-traditional amphiphiles. PMID:27102801

  18. Magnetic ionic liquids: synthesis and characterization

    International Nuclear Information System (INIS)

    The synthesis of magnetic ionic liquids (MILs) based on the stable dispersions of magnetic nanoparticles (MNPs) of γ-Fe2O3, Fe3O4, and CoFe2O4 in the ionic liquid 1-n-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMI.NTf2) is reported. The MNPs were obtained by the coprecipitation method. The surface of the α-Fe2O3, Fe3O4, and CoFe2O4 MNPs with mean sizes (XRD) of 9.3, 12.3, and 11.0 nm, respectively were functionalized by 1-n-butyl-3-(3'-trimethoxypropylsilane)- imidazolium chloride. The non functionalized and functionalized MNPs were further characterized by Raman, FTIR-ATR, and FTNIR spectroscopy and by TGA. The stability of the MILs was assigned to the formation of at least one monolayer of the surface modifier agent that mimics the structure of the BMI.NTf2 IL. (author)

  19. Cellulose multilayer Membranes manufacture with Ionic liquid

    KAUST Repository

    Livazovic, S.

    2015-05-09

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

  20. Ternary (liquid + liquid) equilibria of {trifluorotris(perfluoroethyl)phosphate based ionic liquids + thiophene + heptane}: Part 2

    International Nuclear Information System (INIS)

    Highlights: • Ternary (liquid + liquid) equilibria for 3 ionic liquid + thiophene + heptane systems. • The influence of ionic liquid structure on phase diagrams is discussed. • Influence of IL structure on S and β for heptane/thiophene separation is discussed. - Abstract: Ternary (liquid + liquid) equilibria for 3 systems containing ionic liquids {(1-ethyl-3-methylimidazolium trifluorotris(perfluoroethyl)phosphate, 1-(2-hydroxyethyl)-3-methylimidazolium trifluorotris(perfluoroethyl)phosphate, ethyl-dimethyl-(2-methoxyethyl)ammonium trifluorotris(perfluoroethyl)phosphate) + thiophene + heptane} have been determined at T = 298.15 K. The selectivity and solute distribution ratio were calculated for investigated systems and compared with literature values obtained for other systems containing ionic liquids with [FAP]− anions and [emim]+ cations. In each system, high solubility of thiophene and low solubility of heptane in the ionic liquid are observed. The experimental results have been correlated using NRTL model. The influence of the structure of ionic liquid on phase equilibria, selectivity and solute distribution ratio is discussed

  1. Advanced Ionic Liquid Monopropellant for Payload Ascent Vehicles Project

    Data.gov (United States)

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

  2. 离子液体介质中尿素醇解法合成碳酸二甲酯的工艺优化%Optimization of the Synthesis Conditions of Dimethyl Carbonate from Urea and Methanol in Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    卢翠英; 张智芳; 马亚军; 王爱民

    2011-01-01

    以离子液体为介质,采用正交试验法确定尿素醇解法最佳合成碳酸二甲酯的条件,通过极差分析和方差分析法结果对比,最终确定尿素醇解法最佳合成碳酸二甲酯的条件是:150℃下,离子液体与尿素化学计算量比为2.0下合成7个小时。%Dimethyl Carbonate were synthemed from urea and methanol in ionic liquids in the work..The highly productive conditions were explored by using orthogonal expenriment design.Through compareing the results of range analysis and variance analysis,the idea sythemitic conditions of dimethyl carbonate from urea and methanol in ionic liquid were as follows:at 150℃,at 1 of the ratio of ironic liquid to urea,and for 7 hours.

  3. Ionic flotation of uranium from carbonate solutions

    International Nuclear Information System (INIS)

    Experimentally shown is principal possibility of uranium-bearing ion flotation extraction from diluted carbonate solutions using alkyl pyridinium bromides. Optimal conditions of flotation process are determined. The results on flotation are compared with the results of calculation of uranium-bearing solution ionic composition. The sublate nature is confirmed by the IR-spectroscopy method

  4. Modeling of aluminium deposition from chloroaluminate ionic liquids

    OpenAIRE

    Schaltin, Stijn; Ganapathi, Murugan; Binnemans, Koen; Fransaer, Jan

    2011-01-01

    A finite-element model of the electrodeposition of aluminium from chloroaluminate ionic liquids is introduced. The purpose of this model is to give an explanation for the reasonable current densities that can be achieved in chloroaluminate ionic liquids despite the fact that the electrochemically active Al2Cl7- complexes are transformed into inactive AlCl4- complexes during the electrodeposition of aluminium. The obtainable current density in the electrodeposition from chloroaluminate ionic l...

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

    Science.gov (United States)

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

    2011-11-01

    Ionic liquid based microemulsions were characterized by absorption solvatochromic shifts, (1)H NMR and kinetic measurements in order to investigate the properties of the ionic liquid within the restricted geometry provided by microemulsions and the interactions of the ionic liquid with the interface. Experimental results show a significant difference between the interfaces of normal water and the new ionic liquid microemulsions. Absorption solvatochromic shift experiments and kinetic studies on the aminolysis of 4-nitrophenyl laurate by n-decylamine show that the polarity at the interface of the ionic liquid in oil microemulsions (IL/O) is higher than at the interface of water in oil microemulsions (W/O) despite the fact that the polarity of [bmim][BF(4)(-)] is lower than the polarity of water. (1)H NMR experiments showed that an increase in the ionic liquid content of the microemulsion led to an increase in the interaction between [bmim][BF(4)(-)] and TX-100. The reason for the higher polarity of the microemulsions with the ionic liquid can be explained in terms of the incorporation of higher levels of the ionic liquid at the interface of the microemulsions, as compared to water in the traditional systems. PMID:21820124

  6. Absorption and oxidation of no in ionic liquids

    DEFF Research Database (Denmark)

    2013-01-01

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

  7. Ionic Liquids and Green Chemistry: A Lab Experiment

    Science.gov (United States)

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

    2010-01-01

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

  8. An Ionic Liquid Solution of Chitosan as Organocatalyst

    Directory of Open Access Journals (Sweden)

    René Wilhelm

    2013-11-01

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

  9. Synthesis and Characterization of Dual Acidic Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    Xiao Hua WANG; Guo Hong TAO; Zi Yan ZHANG; Yuan KOU

    2005-01-01

    Novel ionic liquids with dual acidity, of which the cation contains Bronsted acidity and anions contain Lewis acidity were synthesized. These ionic liquids obtained were identified by NMR,FT-IR, SDT and FAB-MS. Their acidities were determined by pyridine probe on IR spectrography.

  10. Absorption and oxidation of nitrogen oxide in ionic liquids

    DEFF Research Database (Denmark)

    Kunov-Kruse, Andreas Jonas; Thomassen, Peter Langelund; Riisager, Anders;

    2016-01-01

    A new strategy for capturing nitrogen oxide, NO, from the gas phase is presented. Dilute NO gas is removed from the gas phase by ionic liquids under ambient conditions. The nitrate anion of the ionic liquid catalyzes the oxidation of NO to nitric acid by atmospheric oxygen in the presence of water...

  11. High energy supercapattery with an ionic liquid solution of LiClO4.

    Science.gov (United States)

    Yu, Linpo; Chen, George Z

    2016-08-15

    A supercapattery combining an ideally polarized capacitor-like electrode and a battery-like electrode is demonstrated theoretically and practically using an ionic liquid electrolyte containing 1-butyl-1-methylpyrrolidinium tri(pentafluoroethyl)trifluorophosphate (BMPyrrFAP), gamma-butyrolactone (γ-GBL) and LiClO4. The electrochemical deposition and dissolution of lithium metal on a platinum and glass carbon electrode were investigated in this ionic liquid solution. The CVs showed that the fresh electrochemically deposited lithium metal was stable in the electrolyte, which encouraged the investigation of this ionic liquid solution in a supercapattery with a lithium battery negative electrode. The active material counted specific energy of the supercapattery based on a lithium negative electrode and an activated carbon (Act-C) positive electrode could reach 230 W h kg(-1) under a galvanostatic charge-discharge current density of 1 mA cm(-2). The positive electrode material (Act-C) was also investigated by CV, AC impedance, SEM and BET. The non-uniform particle size and micropores dominated porous structure of the Act-C enabled its electric double layer capacitor (EDLC) behavior in the ionic liquid solution. The measured specific capacitance of the Act-C in this ionic liquid solution is higher than the same Act-C in aqueous solution, which indicates the Act-C can also perform well in the ionic liquid electrolyte. PMID:27228429

  12. Bottom-up electrochemical preparation of solid-state carbon nanodots directly from nitriles/ionic liquids using carbon-free electrodes and the applications in specific ferric ion detection and cell imaging

    Science.gov (United States)

    Niu, Fushuang; Xu, Yuanhong; Liu, Mengli; Sun, Jing; Guo, Pengran; Liu, Jingquan

    2016-03-01

    Carbon nanodots (C-dots), a new type of potential alternative to conventional semiconductor quantum dots, have attracted numerous attentions in various applications including bio-chemical sensing, cell imaging, etc., due to their chemical inertness, low toxicity and flexible functionalization. Various methods including electrochemical (EC) methods have been reported for the synthesis of C-dots. However, complex procedures and/or carbon source-containing electrodes are often required. Herein, solid-state C-dots were simply prepared by bottom-up EC carbonization of nitriles (e.g. acetonitrile) in the presence of an ionic liquid [e.g. 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6)], using carbon-free electrodes. Due to the positive charges of BMIM+ on the C-dots, the final products presented in a precipitate form on the cathode, and the unreacted nitriles and BMIMPF6 can be easily removed by simple vacuum filtration. The as-prepared solid-state C-dots can be well dispersed in an aqueous medium with excellent photoluminescence properties. The average size of the C-dots was found to be 3.02 +/- 0.12 nm as evidenced by transmission electron microscopy. Other techniques such as UV-vis spectroscopy, fluorescence spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy were applied for the characterization of the C-dots and to analyze the possible generation mechanism. These C-dots have been successfully applied in efficient cell imaging and specific ferric ion detection.Carbon nanodots (C-dots), a new type of potential alternative to conventional semiconductor quantum dots, have attracted numerous attentions in various applications including bio-chemical sensing, cell imaging, etc., due to their chemical inertness, low toxicity and flexible functionalization. Various methods including electrochemical (EC) methods have been reported for the synthesis of C-dots. However, complex procedures and/or carbon source-containing electrodes are often

  13. Solubility of natural gas species in ionic liquids and commercial solvents: experiments and Monte Carlo simulations

    NARCIS (Netherlands)

    M. Ramdin; S.P. Balaji; A. Torres-Knoop; D. Dubbeldam; T.W. de Loos; T.J.H. Vlugt

    2015-01-01

    A detailed comparison of the solubility of carbon dioxide (CO2) and methane (CH4) in ionic liquids (ILs) and in conventional solvents like Selexol, Purisol, propylene carbonate, and sulfolane is presented. The solubilities are compared on mole fraction, molality, and volume basis to demonstrate the

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

    Science.gov (United States)

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

    2015-08-14

    We report experimental results on the diffusivity of water in two ionic liquids obtained using the pulsed-gradient spin-echo NMR method. Both ionic liquids have the same cation, 1-butyl-1-methylpyrrolidinium, but different trifluoromethyl-containing anions. One has a strongly hydrophobic anion, bis(trifluoromethylsulfonyl)amide, while the second has a hydrophilic anion, trifluoromethylsulfonate. Transport of water in these ionic liquids is much faster than would be predicted from hydrodynamic laws, indicating that the neutral water molecules experience a very different friction than the anions and cations at the molecular level. Temperature-dependent viscosities, conductivities, and densities are reported as a function of water concentration to further analyze the properties of the ionic liquid-water mixtures. These results on the properties of water in ionic liquids should be of interest to researchers in diverse areas ranging from separations, solubilizing biomass and energy technologies. PMID:26277141

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

    Energy Technology Data Exchange (ETDEWEB)

    Fadeeva, Tatiana A.; DeVine, Jessalyn A.; Castner, Edward W., E-mail: ed.castner@rutgers.edu [Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 (United States); Husson, Pascale [CNRS, UMR 6296, Institut de Chimie de Clermont-Ferrand, BP 80026, F-63171 Aubière (France); Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand (France); Costa Gomes, Margarida F. [CNRS, UMR 6296, Institut de Chimie de Clermont-Ferrand, BP 80026, F-63171 Aubière (France); Greenbaum, Steven G. [Department of Physics and Astronomy, Hunter College, CUNY, New York, New York 10065 (United States)

    2015-08-14

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

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

    International Nuclear Information System (INIS)

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

  17. Polarization versus Temperature in Pyridinium Ionic Liquids

    DEFF Research Database (Denmark)

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

    2014-01-01

    Electronic polarization and charge transfer effects play a crucial role in thermodynamic, structural, and transport properties of room-temperature ionic liquids (RTILs). These nonadditive interactions constitute a useful tool for tuning physical chemical behavior of RTILs. Polarization and charge...... transfer generally decay as temperature increases, although their presence should be expected over an entire condensed state temperature range. For the first time, we use three popular pyridinium-based RTILs to investigate temperature dependence of electronic polarization in RTILs, based on a nonperiodic...... electronic density description for a cationanion pair. Atom-centered density matrix propagation molecular dynamics, supplemented by a weak coupling to an external bath, is used to simulate the temperature impact on system properties. We show that, quite surprisingly, nonadditivity in the cationanion...

  18. Microregion detection of ionic liquid microemulsions.

    Science.gov (United States)

    Gao, Yanan; Wang, Suqing; Zheng, Liqiang; Han, Shuaibing; Zhang, Xuan; Lu, Deming; Yu, Li; Ji, Yongqiang; Zhang, Gaoyong

    2006-09-15

    Nonaqueous ionic liquid (IL) microemulsion consisting of IL, 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF(4)), surfactant TX-100, and toluene was prepared and the phase behavior of the ternary system was investigated. Electrical conductivity measurement was used for investigating the microregions of the nonaqueous IL microemulsions. On the basis of the percolation theory, the bmimBF(4)-in-toluene (IL/O), bicontinuous, and toluene-in-bmimBF(4) (O/IL) microregions of the microemulsions were successfully identified using insulative toluene as the titration phase. However, this method was invalid when conductive bmimBF(4) acted as the titration phase. The microregions obtained by conductivity measurements were further proved by electrochemical cyclic voltammetry experiments. The results indicated that the conductivity method was feasible for identifying microstructures of the nonaqueous IL microemulsions. PMID:16765365

  19. Ionic Liquids as Advanced Lubricant Fluids

    Directory of Open Access Journals (Sweden)

    Francisco-José Carrión

    2009-08-01

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

  20. Graphene terahertz modulators by ionic liquid gating

    CERN Document Server

    Wu, Yang; Qiu, Xuepeng; Liu, Jingbo; Deorani, Praveen; Banerjee, Karan; Son, Jaesung; Chen, Yuanfu; Chia, Elbert E M; Yang, Hyunsoo

    2015-01-01

    Graphene based THz modulators are promising due to the conical band structure and high carrier mobility of graphene. Here, we tune the Fermi level of graphene via electrical gating with the help of ionic liquid to control the THz transmittance. It is found that, in the THz range, both the absorbance and reflectance of the device increase proportionately to the available density of states due to intraband transitions. Compact, stable, and repeatable THz transmittance modulation up to 93% (or 99%) for a single (or stacked) device has been demonstrated in a broad frequency range from 0.1 to 2.5 THz, with an applied voltage of only 3 V at room temperature.

  1. Inorganic materials synthesis in ionic liquids

    Directory of Open Access Journals (Sweden)

    Christoph Janiak

    2014-01-01

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

  2. Retreating behavior of a charged ionic liquid droplet in a dielectric liquid under electric field

    Science.gov (United States)

    Ahn, Myung Mo; Im, Do Jin; Kang, In Seok

    2013-11-01

    Ionic liquids show great promise as excellent solvents or catalysts in energy and biological fields due to their unique chemical and physical properties. The ionic liquid droplets in microfluidic systems can also be used as a potential platform for chemical biological reactions. In order to control electrically the ionic liquid droplets in a microfluidic device, the charging characteristics of ionic liquid droplets need to be understood. In this work, the charging characteristics of various ionic liquids are investigated by using the parallel plate electrodes system. Under normal situation, a charged droplet shows bouncing motion between electrodes continuously. However, for some special ionic liquids, interesting retreating behavior of charged ionic liquid droplet has been observed. This retreating behavior of ionic liquid droplet has been analyzed experimentally by the image analysis and the electrometer signal analysis. Based on the hypothesis of charge leakage of the retreating ionic liquid droplets, FT-IR spectroscopy analysis has also been performed. The retreating behavior of ionic liquid droplet is discussed from the intermolecular point of view according to the species of ionic liquids. This research was supported by grant No. 2013R1A1A2011956 funded by the Ministry of Science, ICT and Future Planning (MSIP) and by grant No. 2013R1A1A2010483 funded by the Ministry of Education, Science and Technology (MEST) through the NRF.

  3. Layering of ionic liquids on rough surfaces

    Science.gov (United States)

    Sheehan, Alexis; Jurado, L. Andres; Ramakrishna, Shivaprakash N.; Arcifa, Andrea; Rossi, Antonella; Spencer, Nicholas D.; Espinosa-Marzal, Rosa M.

    2016-02-01

    Understanding the behavior of ionic liquids (ILs) either confined between rough surfaces or in rough nanoscale pores is of great relevance to extend studies performed on ideally flat surfaces to real applications. In this work we have performed an extensive investigation of the structural forces between two surfaces with well-defined roughness (force microscopy. Statistical studies of the measured layer thicknesses, layering force, and layering frequency reveal the ordered structure of the rough IL-solid interface. Our work shows that the equilibrium structure of the interfacial IL strongly depends on the topography of the contact.Understanding the behavior of ionic liquids (ILs) either confined between rough surfaces or in rough nanoscale pores is of great relevance to extend studies performed on ideally flat surfaces to real applications. In this work we have performed an extensive investigation of the structural forces between two surfaces with well-defined roughness (force microscopy. Statistical studies of the measured layer thicknesses, layering force, and layering frequency reveal the ordered structure of the rough IL-solid interface. Our work shows that the equilibrium structure of the interfacial IL strongly depends on the topography of the contact. Electronic supplementary information (ESI) available: Optimized geometries and sizes for [HMIM] Ntf2, SEM images of the smooth and rough colloids, frequency of occurrence of layering in the resolved force-distance curves for all investigated systems with [HMIM] Ntf2, layer size and layering force measured with a sharp tip on mica for the same IL, and results of the kinetics experiments. See DOI: 10.1039/c5nr07805a

  4. Energy Efficient Electrochromic Windows Incorporating Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-11-30

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

  5. Femtosecond solvation dynamics in a neat ionic liquid and ionic liquid microemulsion: excitation wavelength dependence.

    Science.gov (United States)

    Adhikari, Aniruddha; Sahu, Kalyanasis; Dey, Shantanu; Ghosh, Subhadip; Mandal, Ujjwal; Bhattacharyya, Kankan

    2007-11-01

    Solvation dynamics in a neat ionic liquid, 1-pentyl-3-methyl-imidazolium tetra-flouroborate ([pmim][BF4]) and its microemulsion in Triton X-100 (TX-100)/benzene is studied using femtosecond up-conversion. In both the neat ionic liquid and the microemulsion, the solvation dynamics is found to depend on excitation wavelength (lambda(ex)). The lambda(ex) dependence is attributed to structural heterogeneity in neat ionic liquid (IL) and in IL microemulsion. In neat IL, the heterogeneity arises from clustering of the pentyl groups which are surrounded by a network of cation and anions. Such a nanostructural organization is predicted in many recent simulations and observed recently in an X-ray diffraction study. In an IL microemulsion, the surfactant (TX-100) molecules aggregate in form of a nonpolar peripheral shell around the polar pool of IL. The micro-environment in such an assembly varies drastically over a short distance. The dynamic solvent shift (and average solvation time) in neat IL as well as in IL microemulsions decreases markedly as lambda(ex) increases from 375 to 435 nm. In a [pmim][BF4]/water/TX-100/benzene quaternary microemulsion, the solvation dynamics is slower than that in a microemulsion without water. This is ascribed to the smaller size of the water containing microemulsion. The anisotropy decay in an IL microemulsion is found to be faster than that in neat IL. PMID:17944511

  6. Physics of transduction in ionic liquid-swollen Nafion membranes

    Science.gov (United States)

    Bennett, Matthew; Leo, Donald

    2006-03-01

    Ionic polymer transducers are a class of electroactive polymers that are able to generate large strains (1-5%) in response to low voltage inputs (1-5 V). Additionally, these materials generate electrical charge in response to mechanical strain and are therefore able to operate as soft, distributed sensors. Traditionally, ionic polymer transducers have been limited in their application by their hydration dependence. This work seeks to overcome this limitation by replacing the water with an ionic liquid. Ionic liquids are molten salts that exhibit very high thermal and electrochemical stability while also possessing high ionic conductivity. Results have shown that an ionic liquid-swollen ionic polymer transducer can operate for more than 250,000 cycles in air as compared to about 2,000 cycles for a water-swollen transducer. The current work examines the mechanisms of transduction in ionic liquid-swollen transducers based on Nafion polymer membranes. Specifically, the morphology and relevant ion associations within these membranes are investigated by the use of small-angle X-ray scattering (SAXS), Fourier transform infrared spectroscopy (FTIR), and nuclear magnetic resonance spectroscopy (NMR). These results reveal that the ionic liquid interacts with the membrane in much the same way that water does, and that the counterions of the Nafion polymer are the primary charge carriers. The results of these analyses are compared to the macroscopic transduction behavior in order to develop a model of the charge transport mechanism responsible for electromechanical coupling in these membranes.

  7. Protic Cationic Oligomeric Ionic Liquids of the Urethane Type

    DEFF Research Database (Denmark)

    Shevchenko, V. V.; Stryutsky, A. V.; Klymenko, N. S.; Gumennaya, M. A.; Fomenko, A. A.; Trachevsky, V. V.; Davydenko, V. V.; Bliznyuk, V. N.; Dorokhin, Andriy

    2014-01-01

    Protic oligomeric cationic ionic liquids of the oligo(ether urethane) type are synthesized via the reaction of an isocyanate prepolymer based on oligo(oxy ethylene)glycol with M = 1000 with hexamethylene-diisocyanate followed by blocking of the terminal isocyanate groups with the use of amine...... derivatives of imidazole, pyridine, and 3-methylpyridine and neutralization of heterocycles with ethanesulfonic acid and p-toluenesulfonic acid. The structures and properties of the synthesized oligomeric ionic liquids substantially depend on the structures of the ionic groups. They are amorphous at room...... temperature, but ethanesulfonate imidazolium and pyridinium oligomeric ionic liquids form a low melting crystalline phase. The proton conductivities of the oligomeric ionic liquids are determined by the type of cation in the temperature range 80-120 degrees C under anhydrous conditions and vary within five...

  8. Predictions of Physicochemical Properties of Ionic Liquids with DFT

    Directory of Open Access Journals (Sweden)

    Karl Karu

    2016-07-01

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

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

    CERN Document Server

    Ng, Y S; Hashim, M A

    2014-01-01

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

  10. Behaviour of actinides in room temperature ionic liquids

    International Nuclear Information System (INIS)

    The room temperature ionic liquids are potentially interesting for the treatment of nuclear fuel. But the knowledge of the behaviour of actinides in the ionic liquids is fragmented because these solvents are new, young and many. In a first time, the ionic liquids [BuMeIm][Tf2N] and [MeBu3N][Tf2N] have been studied in α and γ irradiation with different atmosphere (argon and air) and concentrations of water. ESIMS, NMR and liquid chromatography coupled ESI-MS analysis demonstrate a multitude of degradation products but in very small quantities. This good radiolytic stability makes it a major advantage for the studies of actinides. In a second time, the interaction between an anionic complex of uranium (UCl62-) and the cation of the ionic liquid and too the study of the hydrolysis of An4+ (An uranium, neptunium, plutonium) were conducted in different ionic liquids ([MeBu3N][Tf2N], [BuMe2Im][Tf2N] and [BuMeIm][Tf2N]). The experimental results showed that the intensity of these interactions between UCl62- anion and the ionic liquid cation depends on the latter and follows the order: MeBu3N+ ∼ BuMe2Im+ ≤BuMeIm+. In addition, the results obtained by UV/Vis spectroscopy showed that the reaction of hydrolysis in the ionic liquids is slow, secondary compared to the oxidation or the disproportionation and that the amount of water in ionic liquid must be relatively large compared to the concentration of actinide. The results from the coupling of different analytical techniques (NMR, mass spectrometry, UV-Visible, Infra-red, Electrochemistry..) have allowed a first approach in the understanding of the actinides in the room temperature ionic liquids. (author)

  11. Nitrogen and sulfur co-doped carbon with three-dimensional ordered macroporosity: An efficient metal-free oxygen reduction catalyst derived from ionic liquid

    Science.gov (United States)

    Wu, Hui; Shi, Liang; Lei, Jiaheng; Liu, Dan; Qu, Deyu; Xie, Zhizhong; Du, Xiaodi; Yang, Peng; Hu, Xiaosong; Li, Junsheng; Tang, Haolin

    2016-08-01

    The development of efficient and durable catalyst for oxygen reduction reaction (ORR) is critical for the practical application of proton exchange membrane fuel cell (PEMFC). A novel imidazole based ionic liquid is synthesized in this study and used subsequently for the preparation of a N and S co-doped metal-free catalyst with three dimensional ordered microstructure. The catalyst prepared at 1100 °C showed improved ORR catalytic performance and stability compared to commercial Pt/C catalyst. We demonstrate that the high graphitic N content and high degree of graphitization of the synthesized catalyst is responsible for its superb ORR activity. Our results suggest that the N and S co-doped metal-free catalyst reported here is a promising alternative to traditional ORR catalyst based on noble metal. Furthermore, the current study also demonstrate that importance of morphology engineering in the development of high performance ORR catalyst.

  12. A structural investigation of ionic liquid mixtures.

    Science.gov (United States)

    Matthews, Richard P; Villar-Garcia, Ignacio J; Weber, Cameron C; Griffith, Jeraime; Cameron, Fiona; Hallett, Jason P; Hunt, Patricia A; Welton, Tom

    2016-03-16

    The structures of mixtures of ionic liquids (ILs) featuring a common 1-butyl-3-methylimidazolium ([C4C1im](+)) cation but different anions have been investigated both experimentally and computationally. (1)H and (13)C NMR of the ILs and their mixtures has been performed both on the undiluted liquids and those diluted by CD2Cl2. These experiments have been complemented by quantum chemical density functional theory calculations and molecular dynamics simulations. These techniques have identified the formation of preferential interactions between H(2) of the imidazolium cation and the most strongly hydrogen bond (H-bond) accepting anion. In addition, a preference for the more weakly H-bond accepting anion to interact above the imidazolium ring through anion-π(+) interactions has been identified. The modelling of these data has identified that the magnitude of these preferences are small, of the order of only a few kJ mol(-1), for all IL mixtures. No clustering of the anions around a specific cation could be observed, indicating that these interactions arise from the reorientation of the cation within a randomly assigned network of anions. π(+)-π(+) stacking of the imidazolium cations was also studied and found to be promoted by ILs with a strong H-bond accepting anion. Stacking interactions are easily disrupted by the introduction of small proportions (accounting for why most IL mixtures exhibit ideal, or nearly ideal, behaviour. PMID:26947103

  13. Particle aggregation mechanisms in ionic liquids.

    Science.gov (United States)

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

    2014-05-28

    Aggregation of sub-micron and nano-sized polystyrene latex particles was studied in room temperature ionic liquids (ILs) and in their water mixtures by time-resolved light scattering. The aggregation rates were found to vary with the IL-to-water molar ratio in a systematic way. At the water side, the aggregation rate is initially small, but increases rapidly with increasing IL content, and reaches a plateau value. This behaviour resembles simple salts, and can be rationalized by the competition of double-layer and van der Waals forces as surmised by the classical theory of Derjaguin, Landau, Verwey, and Overbeek (DLVO). At the IL side, aggregation slows down again. Two generic mechanisms could be identified to be responsible for the stabilization in ILs, namely viscous stabilization and solvation stabilization. Viscous stabilization is important in highly viscous ILs, as it originates from the slowdown of the diffusion controlled aggregation due to the hindrance of the diffusion in a viscous liquid. The solvation stabilization mechanism is system specific, but can lead to a dramatic slowdown of the aggregation rate in ILs. This mechanism is related to repulsive solvation forces that are operational in ILs due to the layering of the ILs close to the surfaces. These two stabilization mechanisms are suspected to be generic, as they both occur in different ILs, and for particles differing in surface functionalities and size. PMID:24727976

  14. Soft ionization of thermally evaporated hypergolic ionic liquid aerosols

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-03-16

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

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

    OpenAIRE

    Ng, Yee Sern; Jayakumar, N.S.; Hashim, M A

    2014-01-01

    Room temperature ionic liquids show potential as an alternative to conventional organic membrane solvents mainly due to their properties of low vapor pressure, low volatility and they are often stable. In the present work, the technical feasibilities of room temperature ionic liquids as bulk liquid membranes for phenol removal were investigated experimentally. Three ionic liquids with high hydrophobicity were used and their phenol removal efficiency, membrane stability and membrane loss were ...

  16. Partition coefficients of organics in ionic liquid–supercritical carbon dioxide systems

    Czech Academy of Sciences Publication Activity Database

    Roth, Michal

    Ústav chemických procesů AV ČR, v. v. i, 2015. s. 11. [EU COST CM1206 Action Exchange on Ionic Liquids Workshop. 21.04.2015-22.04.2015, Praha] Institutional support: RVO:68081715 Keywords : ionic liquid * supercritical carbon dioxide * partition coefficient Subject RIV: CB - Analytical Chemistry, Separation https://drive.google.com/file/d/0ByvzfYWTeIHMaDRlMU5IVzQtSGs/view?pli=1

  17. Partition coefficients of organics in ionic liquid–supercritical carbon dioxide systems

    Czech Academy of Sciences Publication Activity Database

    Roth, Michal

    Ústav chemických procesů AV ČR, v. v. i, 2015. s. 11. [EU COST CM1206 Action Exchange on Ionic Liquids Workshop. 21.04.2015-22.04.2015, Praha] Institutional support: RVO:68081715 Keywords : ionic liquid * supercritical carbon dioxide * partition coefficient Subject RIV: CB - Analytical Chemistry, Separation https://drive. google .com/file/d/0ByvzfYWTeIHMaDRlMU5IVzQtSGs/view?pli=1

  18. First title: Ionic liquids-useful reaction green solvents for the future Second title: ionic liquids are the replacements for environmentally damaging solvents in a wide range of chemical processes.

    Directory of Open Access Journals (Sweden)

    K.Vijaya Bhaskar

    2012-09-01

    "designer solvents”. This means that their properties can be adjusted to suit the requirements of a particular process. Properties such as melting point, viscosity, density, and hydrophobicity can be varied by simple changes to the structure of the ions. For example, the melting points of 1-alkyl-3-methylimidazolium tetrafluoroborates and hexafluorophosphates are a function of the length of the 1-alkyl group, and form liquid crystalline phases for alkyl chain lengths over 12 carbon atoms. Another important property that changes with structure is the miscibility of water in these ionic liquids. For example, 1-alkyl-3-methylimidazolium tetrafluoroborate salts are miscible with water at 25 °C where the alkyl chain length is less than 6, but at or above 6 carbon atoms, they form a separate phase when mixed with water. This behaviour can be of substantial benefit when carrying out solvent extractions or product separations, as the relative solubility’s of the ionic and extraction phase can be adjusted to make the separation as easy as possible. In addition, ionic liquids have practically no vapour pressure which facilitates product separation by distillation. There are also indications that switching from a normal organic solvent to an ionic liquid can lead to novel and unusual chemical reactivity. This opens up a wide field for future investigations into this new class of solvents in catalytic applications. Research into ionic liquids is booming. The first industrial process involving ionic liquids was announced in March 2003, and the potential of ionic liquids for new chemical technologies is beginning to be recognized. One of the primary driving forces behind research into ionic liquids is the perceived benefit of substituting traditional industrial solvents, most of which are volatile organic compounds (VOCs, with non-volatile ionic liquids. Replacement of conventional solvents by ionic liquids would prevent the emission of VOCs, a major source of environmental

  19. Simultaneous Design of Ionic Liquids and Azeotropic Separation Processes

    DEFF Research Database (Denmark)

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

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

  20. Inorganic or organic azide-containing hypergolic ionic liquids.

    Science.gov (United States)

    Joo, Young-Hyuk; Gao, Haixiang; Zhang, Yanqiang; Shreeve, Jean'ne M

    2010-04-01

    Recently extensive research has focused on replacing toxic hydrazine, monomethylhydrazine, and unsymmetrical dimethylhydrazine as liquid propellant fuels. 2-Azido-N,N-dimethylethylamine (1) is a good candidate to replace hydrazine derivatives in certain hypergolic fuel applications. Energetic ionic liquids that contain the 2-azido-N,N,N-trimethylethylammonium cation with nitrocyanamide, dicyanamide, dinitramide, or azide anion have been successfully synthesized in good yields by metathesis reactions. Ionic liquids have received considerable attention as energetic materials. The replacement of hydrazine with tertiary ammonium salts is especially attractive since many ionic liquids are models for green chemistry. In this work, new azide-functionalized ionic liquids are demonstrated to exhibit hypergolic activity with such oxidizers as 100% nitric acid or nitrogen tetraoxide (NTO). PMID:20175509

  1. Electron solvation and geminate ion recombination in ionic liquids

    International Nuclear Information System (INIS)

    The behavior of radiation-induced active species in ionic liquids attract much attention from view point of radiation induced decomposition and reaction in ionic liquids. The formation process, lifetime, yield and reactivity of solvated electrons were studied in alkyl ammonium ionic liquid by electron beam pulse radiolysis method. As a result, the G-value of the solvated electron is about 1, the lifetime is about 300 ns, the high efficiency reaction between the dry electron and solute were clarified. Most of the ionized electron would recombine with parent radical cation geminately. Pre-solvated electron reaction and geminate ion recombination were investigated using the femtosecond pulse radiolysis system. (author)

  2. Recovery of Ionic Liquids from aqueous solution by Nanofiltration

    OpenAIRE

    Fernández Dámaso, José Francisco

    2011-01-01

    The T-SAR methodology was combined with membrane characterization methods. An application of the combined approach was demonstrated with two commercial nanofiltration membranes and it was possible to successfully predict their performance for the recovery of ionic liquids from aqueous solution. Using model solutions of Pyr16 (CF3SO2)2N, it could be evidenced the formation of a new phase of ionic liquid during the concentration process. In this case, 66% of the ionic liquid was separated and t...

  3. Periodicity and map for discovery of new ionic liquids

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Suojiang

    2006-01-01

    [1]Trohalaki,S.,Pachter,R.,Drake,G.W.,Hawkins,T.,Quantitative structure-property relationships for melting points and densities of ionic liquids,Energy & Fuels,2005,19:279-284.[2]Holbery,J.D.,Seddon,K.R.,The phase behavior of 1-alkyl-3-methylimidazolium tetrafluoroborates,ionic liquids and ionic liquid crystals,J.Chem.Soc.Dalton Trans.,1999,13:2133-2139.[3]Katritzky,A.R.,Lomaka,A.,Petrukhin,R.et al.,QSPR correlation of the melting point for pyridinium bromides,potential ionic liquids,J.Chem.Inf.Comput.Sci.,2002,42:71-74.[4]Katritzky,A.R.,Jain,R.,Lomaka,A.et al.,Correlation of the melting points of potential ionic liquids (imidazolium bromides and benzimidazolium bromides) using the CODESSA program,J.Chem.Inf.Comput.Sci.,2002,42:225-231.[5]Eike,D.M.,Brennecke,J.F.,Maginn,E.J.,Predicting melting points of quaternary ammonium ionic liquids,Green Chemistry,2003,5:323-328.[6]Dupont,J.,Souza,R.F.,Suarez,A.Z.,Ionic liquid (molten salt) phase organometallic catalysis,J.Chem.Rev.,2002,102:3667-3692.[7]Turner,E.A.,Pye,C.C.,Singer,R.D.,Use of ab initio calculations toward the rational design of room temperature ionic liquids,J.Phys.Chem.A,2003,107(13):2277-2288.[8]Morrow,T.I.,Maginn,E.J.,Molecular dynamics study of the ionic liquid 1-n-butyl-3-methylimidazolium hexafluorophosphate,J.Phys.Chem.B,2002,106:12807-12813.[9]Cadena,C.,Antony,J.L.,Shah,J.K.et al.,Why is CO2 so soluble in imidazolium-based ionic liquids? J.Am.Chem.Soc.,2004,126(16):5300-5308.[10]Liu,Z.,Huang,S.,Wang,W.,A refined force field for molecular simulation of imidazolium-based ionic liquids,J.Phys.Chem.B,2004,108(34):12978-12989.[11]Earle,M.J,Seddon,K.R.,Ionic liquids,green solvents for the future,Pure Appl.Chem.,2000,72(7):1391-1398.[12]Mendeleev on periodicity:I and II,http://www.rod.beavon.clara.net/periodic1.htm[13]Hoffmann,R.,Building bridges between inorganic and organic chemistry,Angew.Chem.Int.Ed.Engl.,1982,21(10):711-800.

  4. Thermal boundary conductance of hydrophilic and hydrophobic ionic liquids

    Science.gov (United States)

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

    2015-03-01

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

  5. Triphilic Ionic-Liquid Mixtures: Fluorinated and Non-fluorinated Aprotic Ionic-Liquid Mixtures.

    Science.gov (United States)

    Hollóczki, Oldamur; Macchiagodena, Marina; Weber, Henry; Thomas, Martin; Brehm, Martin; Stark, Annegret; Russina, Olga; Triolo, Alessandro; Kirchner, Barbara

    2015-10-26

    We present here the possibility of forming triphilic mixtures from alkyl- and fluoroalkylimidazolium ionic liquids, thus, macroscopically homogeneous mixtures for which instead of the often observed two domains-polar and nonpolar-three stable microphases are present: polar, lipophilic, and fluorous ones. The fluorinated side chains of the cations indeed self-associate and form domains that are segregated from those of the polar and alkyl domains. To enable miscibility, despite the generally preferred macroscopic separation between fluorous and alkyl moieties, the importance of strong hydrogen bonding is shown. As the long-range structure in the alkyl and fluoroalkyl domains is dependent on the composition of the liquid, we propose that the heterogeneous, triphilic structure can be easily tuned by the molar ratio of the components. We believe that further development may allow the design of switchable, smart liquids that change their properties in a predictable way according to their composition or even their environment. PMID:26305804

  6. DFT Study of the Reaction Mechanisms of Carbon Dioxide and its Isoelectronic Molecules CS2 and OCS Dissolved in Pyrrolidinium and Imidazolium Acetate Ionic Liquids.

    Science.gov (United States)

    Danten, Y; Cabaço, M I; Coutinho, J A P; Pinaud, Noël; Besnard, M

    2016-06-16

    The reaction mechanisms of CO2 and its isoelectronic molecules OCS and CS2 dissolved in N-butyl-N-methylpyrrolidinium acetate and in 1-butyl-3-methylimidazolium acetate were investigated by DFT calculations in "gas phase". The analysis of predicted multistep pathways allowed calculating energies of reaction and energy barriers of the processes. The major role played by the acetate anion in the degradation of the solutes CS2 and OCS as well as in the capture of OCS and CO2 by the imidazolium ring is highlighted. In both ionic liquids, this anion governs the conversion of CS2 into OCS and of OCS into CO2 through interatomic S-O exchanges between the anion and the solutes with formation of thioacetate anions. In imidazolium acetate, the selective capture of CS2 and OCS by the imidazolium ring competes with the S-O exchanges. From the calculated values of the energy barriers a basicity scale of the anions is proposed. The (13)C NMR chemical shifts of the predicted adducts were calculated and agree well with the experimental observations. It is argued that the scenario issued from the calculated pathways is shown qualitatively to be independent from the functionals and basis set used, constitute a valuable tool in the understanding of chemical reactions taking place in liquid phase. PMID:27186961

  7. Transport and Molecular Organization in Ionic Liquids of Various Structures

    Czech Academy of Sciences Publication Activity Database

    Andresová, Adéla; Bendová, Magdalena; Storch, Jan; Traika, M.; Wagner, Zdeněk; Husson, P.

    Eindhoven : -, 2014, O65. ISBN N. [European Symposium on Applied Thermodynamics (ESAT 2014) "Experiments meet Theory and Simulation" /27./. Eindhoven (NL), 06.07.2014-09.07.2014] Institutional support: RVO:67985858 Keywords : ionicity * transport * ionic liquids Subject RIV: CF - Physical ; Theoretical Chemistry

  8. Water in Room Temperature Ionic Liquids

    Science.gov (United States)

    Fayer, Michael

    2014-03-01

    Room temperature ionic liquids (or RTILs, salts with a melting point below 25 °C) have become a subject of intense study over the last several decades. Currently, RTIL application research includes synthesis, batteries, solar cells, crystallization, drug delivery, and optics. RTILs are often composed of an inorganic anion paired with an asymmetric organic cation which contains one or more pendant alkyl chains. The asymmetry of the cation frustrates crystallization, causing the salt's melting point to drop significantly. In general, RTILs are very hygroscopic, and therefore, it is of interest to examine the influence of water on RTIL structure and dynamics. In addition, in contrast to normal aqueous salt solutions, which crystallize at low water concentration, in an RTIL it is possible to examine isolated water molecules interacting with ions but not with other water molecules. Here, optical heterodyne-detected optical Kerr effect (OHD-OKE) measurements of orientational relaxation on a series of 1-alkyl-3-methylimidazolium tetrafluoroborate RTILs as a function of chain length and water concentration are presented. The addition of water to the longer alkyl chain RTILs causes the emergence of a long time bi-exponential orientational anisotropy decay. Such decays have not been seen previously in OHD-OKE experiments on any type of liquid and are analyzed here using a wobbling-in-a-cone model. The orientational relaxation is not hydrodynamic, with the slowest relaxation component becoming slower as the viscosity decreases for the longest chain, highest water content samples. The dynamics of isolated D2O molecules in 1-butyl-3-methylimidazolium hexafluorophosphate (BmImPF6) were examined using two dimensional infrared (2D IR) vibrational echo spectroscopy. Spectral diffusion and incoherent and coherent transfer of excitation between the symmetric and antisymmetric modes are examined. The coherent transfer experiments are used to address the nature of inhomogeneous

  9. Charge trapping in imidazolium ionic liquids.

    Science.gov (United States)

    Shkrob, Ilya A; Wishart, James F

    2009-04-23

    Room-temperature ionic liquids (ILs) are a promising class of solvents for applications ranging from photovoltaics to solvent extractions. Some of these applications involve the exposure of the ILs to ionizing radiation, which stimulates interest in their radiation and photo- chemistry. In the case of ILs consisting of 1,3-dialkylimidazolium cations and hydrophobic anions, ionization, charge transfer and redox reactions yield charge-trapped species thought to be radicals resulting from neutralization of the constituent ions. Using computational chemistry methods and the recent results on electron spin resonance (ESR) and transient absorption spectroscopy of the ionized ILs, we argue that electron localization in the imidazolium ILs yields a gauche dimer radical cation with the elongated C(2)-C(2) bond. This species is shown to absorb in the near-infrared and the visible regions and accounts for the observed ESR spectra. We suggest that the excess electron in these aromatic ILs is localized as such a dimeric ion, and consider the chemical implications of this attribution. We also suggest that three-electron N-N bonding with the formation of a dimer radical anion occurs for amide anions, such as dicyanamide, when the parent anion traps holes; steric hindrance prevents the analogous reaction for bis(triflyl)amide anion. For another anion of practical importance, bis(oxalato)borate, a pathway involving the elimination of CO(2) is suggested. Together, these results indicate the unanticipated tendency of the ILs to localize primary charges as radical ions as opposed to neutral radicals. Thus, it appears that secondary chemistry in the ionized ILs may be dominated by radical ion reactions, similarly to the previously studied conventional organic liquids, depending on the composition of the IL. PMID:19323543

  10. Morphology-induced low temperature conductivity in ionic liquids

    Science.gov (United States)

    Erbas, Aykut; Olvera de La Cruz, Monica; Olvera de la Cruz Team

    Ionic liquids exhibit nano-scale liquid crystalline order depending on the polymeric details of salt molecules. The resulting morphology and temperature behavior are key factors in determining the room temperature conductivity of ionic liquids. Here we discuss the phase behavior and related ionic conductivities of dry ionic liquids with volume fractions close to unity by using extensive molecular dynamics simulations. Temperature dependence, effective persistence length of tails, and excluded volume symmetry of amphiphilic ionic liquid molecules are investigated in large scale systems with short and long-range electrostatics. Our results suggest that by adjusting stiffness of the amphiphilic molecules and excluded volume interactions, lamellar or interconnected 3D phases can be obtained. Resulting phases have significant effects on the conductive properties. If there is no excluded volume asymmetry along the molecules, mostly lamellar phases with anisotropic conductivities emerge. If the excluded volume interactions become asymmetric, lamellar phases are replaced by interconnected phases consist of charged groups. Within temperature ranges that morphological phases are observed, conductivities exhibit low-temperature maxima in accord with experiments of ionic liquid-based liquid Center of Bio-inspried Energy Center (CBES).

  11. Nanodroplet cluster formation in ionic liquid microemulsions.

    Science.gov (United States)

    Gao, Yanan; Voigt, Andreas; Hilfert, Liane; Sundmacher, Kai

    2008-08-01

    A common ionic liquid (IL), 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF(4)), is used as polar solvent to induce the formation of a reverse bmimBF(4)-in-toluene IL microemulsion with the aid of the nonionic surfactant Triton X-100. The swelling process of the microemulsion droplets by increasing bmimBF(4) content is detected by dynamic light scattering (DLS), conductivity, UV/Vis spectroscopy, and freeze-fracture transmission electron microscopy (FF-TEM). The results show that the microemulsion droplets initially formed are enlarged by the addition of bmimBF(4). However, successive addition of bmimBF(4) lead to the appearance of large-sized microemulsion droplet clusters (200-400 nm). NMR spectroscopic analysis reveal that the special structures and properties of bmimBF(4) and Triton X-100 together with the polar nature of toluene contribute to the formation of such self-assemblies. These unique self-assembled structures of IL-based microemulsion droplet clusters may have some unusual and unique properties with a number of interesting possibilities for potential applications. PMID:18576451

  12. Ionic Liquids – Development and Challenges in Industrial Application

    Directory of Open Access Journals (Sweden)

    Cvjetko Bubalo, M.

    2014-05-01

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

  13. Production of biofuels and chemicals with ionic liquids

    CERN Document Server

    Fang, Zhen; Qi, Xinhua

    2013-01-01

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

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

    Data.gov (United States)

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

  15. The radiation chemistry of ionic liquids: A review

    International Nuclear Information System (INIS)

    Ionic liquids have received increasing attention as media for radiochemical separations. Recent literature includes examinations of the efficiencies and mechanisms of the solvent extraction of lanthanides, actinides and fission products into ionic liquid solutions. For radiochemical applications, including as replacement solvents for nuclear fuel reprocessing, a thorough understanding of the radiation chemistry of ionic liquids will be required. Such an understanding can be achieved based on a combination of steady-state radiolysis experiments coupled with post-irradiation product identification and pulse-radiolysis experiments to acquire kinetic information. These techniques allow for the elucidation of radiolytic mechanisms. This contribution reviews the current ionic liquid radiation chemistry literature as it affects separations, with these considerations in mind

  16. Use of ionic liquids in biodiesel production: a review

    Directory of Open Access Journals (Sweden)

    L. Andreani

    2012-03-01

    Full Text Available This paper discusses the feasibility of the use of ionic liquids as catalysts in the biodiesel production field, describing some studies already published in the literature on this theme. Ionic liquids are regarded as a new generation of catalysts in the chemical industry, with several uses in different commercial segments. However only a few publications involving this topic can be found in the literature addressing the manufacture of biodiesel from vegetable oils or animal fats. Through the analysis of the data generated in the studies reviewed, it is possible to affirm that ionic liquids present great potential as catalysts for biodiesel production, but there are some challenges to be faced, such as the production of ionic liquids with low cost, easy recovery and with the possibility of reutilization of the catalyst for several cycles.

  17. Synthesis of Multiester-appended and Multicarboxylic-appended Imidazolium Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    Wei Guo GENG; Xue Hui LI; Le Fu WANG; Hong Li DUAN; Wei Ping PAN

    2006-01-01

    Multiester-appended imidazolium ionic liquids were synthesized in a quatemization reaction between the imidazole derivatives carrying single or double esters and ethyl chloroacetate or bromoethane. Multicarboxylic-appended imidazolium ionic liquids were achieved from the hydrolysis of the corresponding ionic liquids. The influences of multifunctional groups on the transition temperatures and viscosity of these new ionic liquids were investigated.

  18. Separating closely resembling steroids with ionic liquids in liquid-liquid extraction systems

    NARCIS (Netherlands)

    Vitasari, C.R.; Gramblicka, M.; Gibcus, K.; Visser, T.J.; Geertman, R.M.; Schuur, B.

    2015-01-01

    Separation of steroids by liquid–liquid extraction with ionic liquids (ILs) as solvent was studied both experimentally and by simulation using a model mixture of progesterone and pregnenolone. The studies involved a solvent screening using COSMO-RS software for estimation of progesterone solubility.

  19. Lead-Salt Quantum-Dot Ionic Liquids

    KAUST Repository

    Sun, Liangfeng

    2010-03-08

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

  20. First Claisen Rearrangement Reaction in Ionic Liquids with Microwave Heating

    Institute of Scientific and Technical Information of China (English)

    XU Li-Wen; LI Fu-Wei; XIA Chun-Gu

    2003-01-01

    @@ We have demonstrated the first use of the common ionic liquids, [1] bmimBr, bmimBF4 and bmimPF6 as an environmentally benign solvent for the simple Claisen rearrangement under microwave irradiation. In many cases, the re action was carried out in toxic solvents of high boiling point. [2] Here we reported the first example of Claisen rear rangement reaction in green solvents, ionic liquids, under microwave irradiation.

  1. Electromechanical Transduction in Ionic Liquid-Swollen Nafion Membranes

    OpenAIRE

    Bennett, Matthew Damon

    2005-01-01

    Traditionally, water has been used as the diluent for ionomeric polymer transducers. The water mobilizes the counterions within the polymer and allows electromechanical transduction to occur. However, these water-swollen devices have limited stability when operated in a non-aqueous environment. In this work, ionic liquids are demonstrated as viable diluents for ionomeric polymer transducers based on Nafion membranes. Ionic liquids are molten salts that are highly thermally stable and have...

  2. Use of ionic liquids in biodiesel production: a review

    OpenAIRE

    ANDREANI, L; Rocha, J.D.

    2012-01-01

    This paper discusses the feasibility of the use of ionic liquids as catalysts in the biodiesel production field, describing some studies already published in the literature on this theme. Ionic liquids are regarded as a new generation of catalysts in the chemical industry, with several uses in different commercial segments. However only a few publications involving this topic can be found in the literature addressing the manufacture of biodiesel from vegetable oils or animal fats. Through the...

  3. Electrorefining of aluminum alloy in ionic liquids at low temperatures

    OpenAIRE

    Kamavaram V.; Mantha D.; Reddy R.G.

    2003-01-01

    The electrorefining of aluminum alloy (A360) in ionic liquids at low temperatures has been investigated. The ionic liquid electrolyte was prepared by mixing anhydrous AlCl3 and 1-Butyl-3- methylimidazolium chloride (BMIC) in appropriate proportions. The effect of the cell voltage temperature, and the composition of the electrolyte on the electrorefining process has been studied. The characterization of the deposited aluminum was performed using scanning electron microscopy (SEM) and X-ray dif...

  4. Liquid-liquid extraction of neodymium(III) by dialkylphosphate ionic liquids from acidic medium: the importance of the ionic liquid cation

    OpenAIRE

    Rout, Alok; Kotlarska, Justyna; Dehaen, Wim; Binnemans, Koen

    2013-01-01

    The ionic liquids 1-hexyl-3-methylimidazolium bis(2-ethylhexyl)phosphate, [C6mim][DEHP], 1-hexyl-1-methylpyrrolidinium bis(2-ethylhexyl)phosphate, [C6mpyr][DEHP], and tetrabutylammonium bis(2-ethylhexyl)phosphate, [N4444][DEHP], were prepared and characterized using 1H and 13C NMR spectroscopy. The extraction behavior of neodymium(III) from nitrate medium by these ionic liquids, diluted with the room temperature ionic liquids 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C6m...

  5. Voltammetric sensing of bisphenol A based on a single-walled carbon nanotubes/poly{3-butyl-1-[3-(N-pyrrolyl)propyl] imidazolium ionic liquid} composite film modified electrode

    International Nuclear Information System (INIS)

    Highlights: • Single-walled carbon nanotubes (SWCNTs)-ionic liquid (IL) nanocomposite fabrication. • SWCNTs-Poly-IL film modified electrode was prepared and characterized. • Voltammetric behaviors of bisphenol A were investigated thoroughly. • Sensitive voltammetric method for bisphenol A determination was developed. -- Abstract: Using carboxylic acid-functionalized single walled carbon nanotubes (SWCNTs-COO−) as an anion and 3-butyl-1-[3-(N-pyrrolyl)propyl]imidazolium as a cation, a novel SWCNTs-COO-ionic liquid (SWCNTs-COO-IL) nanocomposite was fabricated successfully. The as-prepared SWCNTs-COO-IL nanocomposite was confirmed with transmission electron microscopy, X-ray photoelectron spectroscopy, UV–vis, FTIR and Raman spectroscopy. The SWCNTs-COO-IL nanocomposite was coated onto a glassy carbon electrode surface followed by cyclic voltammetric scanning to fabricate a SWCNTs/poly{3-butyl-1-[3-(N-pyrrolyl)propyl] imidazolium ionic liquid} composite film modified electrode (SWCNTs/Poly-IL/GCE). Scanning electron microscope and electrochemical impedance spectroscopy were used to characterize SWCNTs/Poly-IL/GCE. Electrochemical behaviors of bisphenol A (BPA) at the SWCNTs/Poly-IL/GCE were investigated thoroughly. It was found that an obvious oxidation peak appeared without reduction peak in the reverse scanning, indicating an irreversible electrochemical process. The oxidation peak currents of BPA were linearly related to scan rate in the range of 20–300 mV s−1, suggesting an adsorption controlled process rather than a diffusion controlled process. Differential pulse voltammetry was employed for the voltammetric sensing of BPA. Experimental conditions such as film thickness, pH value, accumulation potential and time that influence the analytical performance of the SWCNTs/Poly-IL/GCE were optimized. Under optimal conditions, the oxidation peak current was linearly related to BPA concentration in the range of 5.0 × 10−9 to 3.0 × 10−5 mol L−1

  6. IONIC LIQUIDS MATERIAL AS MODERN CONTEXT OF CHEMISTRY IN SCHOOL

    Directory of Open Access Journals (Sweden)

    Hernani Hernani

    2016-04-01

    Full Text Available One way to improve students’ chemistry literacy which is demanded in the modernization of modern technology-based chemistry learning is by studying ionic liquids. Low level of scientific literacy of students in Indonesia as revealed in the PISA in 2012 was the main reason of the research. Ionic liquids-based technology are necessary to be applied as a context for learning chemistry because: (1 the attention of the scientific an technology community in the use of ionic liquids as a new generation of green solvent, electrolyte material and fluidic engineering in recent years becomes larger, in line with the strong demands of the industry for the provision of new materials that are reliable, safe, and friendly for various purposes; (2 scientific explanations related to the context of the ionic liquid contains a lot of facts, concepts, principles, laws, models and theories can be used to reinforce the learning content as a media to develop thinking skill (process/competence as demanded by PISA; (3 The modern technology-based ionic liquid can also be used as a discourse to strengthen scientific attitude. The process of synthesis of ionic liquid involves fairly simple organic reagents, so it deserves to be included in the chemistry subject in school.

  7. Employing ionic liquids to deposit cellulose on PET fibers.

    Science.gov (United States)

    Textor, Torsten; Derksen, Leonie; Gutmann, Jochen S

    2016-08-01

    Several ionic liquids are excellent solvents for cellulose. Starting from that finishing of PET fabrics with cellulose dissolved in ionic liquids like 1-ethyl-3-methyl imidazolium acetate, diethylphosphate and chloride, or the chloride of butyl-methyl imidazolium has been investigated. Finishing has been carried out from solutions of different concentrations, using microcrystalline cellulose or cotton and by employing different cross-linkers. Viscosity of solutions has been investigated for different ionic liquids, concentrations, cellulose sources, linkers and temperatures. Since ionic liquids exhibit no vapor pressure, simple pad-dry-cure processes are excluded. Before drying the ionic liquid has to be removed by a rinsing step. Accordingly rinsing with fresh ionic liquid followed by water or the direct rinsing with water have been tested. The amount of cellulose deposited has been investigated by gravimetry, zinc chloride iodine test as well as reactive dyeing. Results concerning wettability, water up-take, surface resistance, wear-resistance or washing stability are presented. PMID:27112860

  8. Thallium Transfer from Hydrochloric Acid Media into Pure Ionic Liquids.

    Science.gov (United States)

    Tereshatov, Evgeny E; Boltoeva, Maria Yu; Mazan, Valerie; Volia, Merinda F; Folden, Charles M

    2016-03-10

    Pure hydrophobic ionic liquids are known to extract metallic species from aqueous solutions. In this work we have systematically investigated thallium (Tl) extraction from aqueous hydrochloric acid (HCl) solutions into six pure fluorinated ionic liquids, namely imidazolium- and pyrrolidinium-based ionic liquids with bis(trifluoromethanesulfonyl)imide and bis(fluorosulfonyl)-imide anions. The dependence of the Tl extraction efficiency on the structure and composition of the ionic liquid ions, metal oxidation state, and initial metal and aqueous acid concentrations have been studied. Tl concentrations were on the order of picomolar (analyzed using radioactive tracers) and millimolar (analyzed using inductively coupled plasma mass spectrometry). The extraction of the cationic thallium species Tl(+) is higher for ionic liquids with more hydrophilic cations, while for the TlX(z)(3-z) anionic species (where X = Cl(-) and/or Br(-)), the extraction efficiency is greater for ionic liquids with more hydrophobic cations. The highest distribution value of Tl(III) was approximately 2000. An improved mathematical model based on ion exchange and ion pair formation mechanisms has been developed to describe the coextraction of two different anionic species, and the relative contributions of each mechanism have been determined. PMID:26769597

  9. Ion Transport in Nanostructured Block Copolymer/Ionic Liquid Membranes

    Science.gov (United States)

    Hoarfrost, Megan Lane

    Incorporating an ionic liquid into one block copolymer microphase provides a platform for combining the outstanding electrochemical properties of ionic liquids with a number of favorable attributes provided by block copolymers. In particular, block copolymers thermodynamically self-assemble into well-ordered nanostructures, which can be engineered to provide a durable mechanical scaffold and template the ionic liquid into continuous ion-conducting nanochannels. Understanding how the addition of an ionic liquid affects the thermodynamic self-assembly of block copolymers, and how the confinement of ionic liquids to block copolymer nanodomains affects their ion-conducting properties is essential for predictable structure-property control. The lyotropic phase behavior of block copolymer/ionic liquid mixtures is shown to be reminiscent of mixtures of block copolymers with selective molecular solvents. A variety of ordered microstructures corresponding to lamellae, hexagonally close-packed cylinders, body-centered cubic, and face-centered cubic oriented micelles are observed in a model system composed of mixtures of imidazolium bis(trifluoromethylsulfonyl)imide ([Im][TFSI]) and poly(styrene- b-2-vinyl pyridine) (PS-b-P2VP). In contrast to block copolymer/molecular solvent mixtures, the interfacial area occupied by each PS-b-P2VP chain decreases upon the addition of [Im][TFSI], indicating a considerable increase in the effective segregation strength of the PS-b-P2VP copolymer with ionic liquid addition. The relationship between membrane structure and ionic conductivity is illuminated through the development of scaling relationships that describe the ionic conductivity of block copolymer/ionic liquid mixtures as a function of membrane composition and temperature. It is shown that the dominant variable influencing conductivity is the overall volume fraction of ionic liquid in the mixture, which means there is incredible freedom in designing the block copolymer architecture

  10. Modern ab initio valence bond theory calculations reveal charge shift bonding in protic ionic liquids.

    Science.gov (United States)

    Patil, Amol Baliram; Bhanage, Bhalchandra Mahadeo

    2016-06-21

    The nature of bonding interactions between the cation and the anion of an ionic liquid is at the heart of understanding ionic liquid properties. A particularly interesting case is a special class of ionic liquids known as protic ionic liquids. The extent of proton transfer in protic ionic liquids has been observed to vary according to the interacting species. Back proton transfer renders protic ionic liquids volatile and to be considered as inferior ionic liquids. We try to address this issue by employing modern ab initio valence bond theory calculations. The results indicate that the bonding in the cation and the anion of a prototypical ionic liquid, ethylammonium nitrate, is fundamentally different. It is neither characteristic of covalent/polar covalent bonding nor ionic bonding but rather charge shift bonding as a resonance hybrid of two competing ionic molecular electronic structure configurations. An investigation of other analogous protic ionic liquids reveals that this charge shift bonding seems to be a typical characteristic of protic ionic liquids while the ionic solid analogue compound ammonium nitrate has less charge shift bonding character as compared to protic ionic liquids. Further the extent of charge shift bonding character has been found to be congruent with the trends in many physicochemical properties such as melting point, conductivity, viscosity, and ionicity of the studied ionic liquids indicating that percentage charge shift character may serve as a key descriptor for large scale computational screening of ionic liquids with desired properties. PMID:27229870

  11. Electrochemical Model for Ionic Liquid Electrolytes in Lithium Batteries

    International Nuclear Information System (INIS)

    ABSTRACT: Room temperature ionic liquids are considered as potential electrolytes for high performance and safe lithium batteries due to their very low vapor pressure and relatively wide electrochemical and thermal stability windows. Unlike organic electrolytes, ionic liquid electrolytes are molten salts at room temperature with dissociated cations and anions. These dissociated ions interfere with the transport of lithium ions in lithium battery. In this study, a mathematical model is developed for transport of ionic components to study the performance of ionic liquid based lithium batteries. The mathematical model is based on a univalent ternary electrolyte frequently encountered in ionic liquid electrolytes of lithium batteries. Owing to the very high concentration of components in ionic liquid, the transport of lithium ions is described by the mutual diffusion phenomena using Maxwell-Stefan diffusivities, which are obtained from atomistic simulation. The model is employed to study a lithium-ion battery where the electrolyte comprises ionic liquid with mppy+ (N-methyl-N-propyl pyrrolidinium) cation and TFSI− (bis trifluoromethanesulfonyl imide) anion. For a moderate value of reaction rate constant, the electric performance results predicted by the model are in good agreement with experimental data. We also studied the effect of porosity and thickness of separator on the performance of lithium-ion battery using this model. Numerical results indicate that low rate of lithium ion transport causes lithium depleted zone in the porous cathode regions as the porosity decreases or the length of the separator increases. The lithium depleted region is responsible for lower specific capacity in lithium-ion cells. The model presented in this study can be used for design of optimal ionic liquid electrolytes for lithium-ion and lithium-air batteries

  12. Solubility data and modeling for sugar alcohols in ionic liquids

    International Nuclear Information System (INIS)

    Highlights: • Solubility of D-sorbitol and xylitol in six ILs. • The (liquid + liquid) phase equilibrium of (SA + IL) with UCST. • Interesting properties of [BMIM][TDI] IL. • The correlation with NRTL model. - Abstract: Ionic liquids (ILs) are novel media characterized by strong interactions with different organic substances which leads to a wide spectrum of applications involving extraction. Ionic liquids have been used as a solvent for sugar alcohols, sugars and hydrates. This work demonstrates the experimental and theoretical study of (liquid + liquid) phase equilibria for two sugar alcohols, D-sorbitol and xylitol in a few ILs based on different cations and anions (namely, 1-ethyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide [EMPIP][NTf2], 1-hexyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide [HMPIP][NTf2], N-hexylquinolinium bis(trifluoromethylsulfonyl)imide [HQuin][NTf2], N-hexylisoquinolinium bis(trifluoromethylsulfonyl)imide [HiQuin][NTf2], 1-butyl-1-methylimidazolium 4,5-dicyano-2-(trifluoromethyl)-imidazolide [BMIM][TDI] and 1-(cyanomethyl)-3-methylimidazolium 4,5-dicyano-2-(trifluoromethyl)-imidazolide [CCNMIM][TDI]). This study was conducted to assess the applicability of the studied ILs for dissolution of these biomass-related materials. (Liquid + liquid) phase equilibrium diagrams (LLE) in binary systems (sugar alcohol + ionic liquid) were measured using the dynamic technique. The influence of the chemical structure of both the ionic liquids and sugar alcohols were established and is discussed

  13. Ionic structure in liquids confined by dielectric interfaces

    Science.gov (United States)

    Jing, Yufei; Jadhao, Vikram; Zwanikken, Jos W.; Olvera de la Cruz, Monica

    2015-11-01

    The behavior of ions in liquids confined between macromolecules determines the outcome of many nanoscale assembly processes in synthetic and biological materials such as colloidal dispersions, emulsions, hydrogels, DNA, cell membranes, and proteins. Theoretically, the macromolecule-liquid boundary is often modeled as a dielectric interface and an important quantity of interest is the ionic structure in a liquid confined between two such interfaces. The knowledge gleaned from the study of ionic structure in such models can be useful in several industrial applications, such as in the design of double-layer supercapacitors for energy storage and in the extraction of metal ions from wastewater. In this article, we compute the ionic structure in a model system of electrolyte confined by two planar dielectric interfaces using molecular dynamics simulations and liquid state theory. We explore the effects of high electrolyte concentrations, multivalent ions, dielectric contrasts, and external electric field on the ionic distributions. We observe the presence of non-monotonic ionic density profiles leading to a layered structure in the fluid which is attributed to the competition between electrostatic and steric (entropic) interactions. We find that thermal forces that arise from symmetry breaking at the interfaces can have a profound effect on the ionic structure and can oftentimes overwhelm the influence of the dielectric discontinuity. The combined effect of ionic correlations and inhomogeneous dielectric permittivity significantly changes the character of the effective interaction between the two interfaces.

  14. Recent advances in the use of ionic liquids for electrochemical sensing.

    Science.gov (United States)

    Silvester, Debbie S

    2011-12-01

    Ionic Liquids are salts that are liquid at (or just above) room temperature. They possess several advantageous properties (e.g. high intrinsic conductivity, wide electrochemical windows, low volatility, high thermal stability and good solvating ability), which make them ideal as non-volatile electrolytes in electrochemical sensors. This mini-review article describes the recent uses of ionic liquids in electrochemical sensing applications (covering the last 3 years) in the context of voltammetric sensing at solid/liquid, liquid/liquid interfaces and carbon paste electrodes, as well as their use in gas sensing, ion-selective electrodes, and for detecting biological molecules, explosives and chemical warfare agents. A comment on the future direction and challenges in this field is also presented. PMID:22013585

  15. Spectrophotometric determination of iron species using ionic liquid ultrasound assisted dispersive liquid--liquid microextraction

    OpenAIRE

    BAZMANDEGAN, ALIREZA; SHABANI, Ali Mohammad HAJI; DADFARNIA, SAYESSTEH; SAEIDI, MAHBOUBEH; MOGHADAM, MASOUD ROHANI

    2015-01-01

    A simple and efficient method for speciation and determination of iron in different water samples was developed. The method is based on ionic liquid ultrasound assisted dispersive liquid--liquid microextraction (IL-USA-DLLME) followed by spectrophotometric determination. Fe(II) is complexed with 2,4,6-tri(2'-pyridyl)-l,3,5-triazine (TPTZ{)}, neutralized through ion pair formation with sodium dodecyl sulfate (SDS) and extracted into 1-hexyl-3-methylimidazolium hexafluorophosphate [C$_{6}$...

  16. Correlation of Liquid-Liquid Equilibria in Ternary Systems Containing Ionic Liquids

    Czech Academy of Sciences Publication Activity Database

    Bendová, Magdalena; Aim, Karel; Klusoň, Petr; Sedláková, Zuzana; Černá, I.; Vašinová, J.

    - : -, 2009, 41/21/. ISBN B. [Thermodynamics 2009. London (GB), 23.09.09-25.09.09] R&D Projects: GA ČR GA104/07/0444; GA ČR GP104/06/P066; GA AV ČR IAA400720710 Institutional research plan: CEZ:AV0Z40720504 Keywords : liquid-liquid equilibria * ionic liquids * correlation Subject RIV: CF - Physical ; Theoretical Chemistry

  17. In situ electron holographic study of Ionic liquid

    International Nuclear Information System (INIS)

    Investigation of the effect of electron irradiation on ionic liquid (IL) droplets using electron holography revealed that electron irradiation changed the electrostatic potential around the IL. The potential for low electron flux irradiation (0.5×1017 e/m2 s) was almost constant as a function of time (up to 180 min). For higher electron flux irradiation (2×1017 e/m2 s), the potential increased exponentially for a certain time, reflecting the charging effect and then leveled off. The IL was found to be changed from liquid to solid state after a significant increase in the electrostatic potential due to electron irradiation. - Highlights: • We investigate the charging effect of ionic liquid using electron holography. • Electron irradiation changed the electrostatic potential around the ionic liquid. • The change of the potential depends on the electron irradiation flux. • The ionic liquid transformed from liquid to solid due electron irradiation. • Solidification of the ionic liquid correlates with the change of the potential

  18. Electrolyte-gated polymer thin film transistors making use of ionic liquids and ionic liquid-solvent mixtures

    Science.gov (United States)

    Sayago, Jonathan; Meng, Xiang; Quenneville, Francis; Liang, Shuang; Bourbeau, Étienne; Soavi, Francesca; Cicoira, Fabio; Santato, Clara

    2015-03-01

    Electrolyte-Gated (EG) transistors, making use of electrolytes as the gating medium, are interesting for their low operation voltage. Furthermore, EG polymer transistors offer the advantage of solution processing, low cost, and mechanical flexibility. Despite the intense research activity in EG transistors, clear guidelines to correlate the properties of the materials used for the transistor channel and electrolytes with the doping effectiveness of the transistor channel are yet to be clearly established. Here, we investigate the use of room temperature ionic liquids (RTILs) based on the [TFSI] anion (namely, [EMIM][TFSI], [BMIM][TFSI], and [PYR14][TFSI]), to gate transistors making use of MEH-PPV as the channel material. Morphological studies of MEH-PPV and RTIL films showed a certain degree of segregation between the two components. All the EG transistors featured clear drain-source current modulations at voltages below 1 V. Polar solvent additives as propylene carbonate were used to improve the transistor response time.

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

    Energy Technology Data Exchange (ETDEWEB)

    Bonetti, Marco; Nakamae, Sawako; Huang, Bo Tao; Wiertel-Gasquet, Cécile; Roger, Michel [Service de Physique de l’Etat Condensé, CEA-IRAMIS-SPEC, CNRS-UMR 3680, CEA Saclay, F-91191 Gif-sur-Yvette Cedex (France); Salez, Thomas J. [Service de Physique de l’Etat Condensé, CEA-IRAMIS-SPEC, CNRS-UMR 3680, CEA Saclay, F-91191 Gif-sur-Yvette Cedex (France); École des Ponts ParisTech, 6 et 8 avenue Blaise Pascal, Champs-sur-Marne, F-77455 Marne-la-Vallée (France)

    2015-06-28

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

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

    International Nuclear Information System (INIS)

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

  1. Lithium conducting ionic liquids based on lithium borate salts

    Energy Technology Data Exchange (ETDEWEB)

    Zygadlo-Monikowska, E.; Florjanczyk, Z.; Sluzewska, K.; Ostrowska, J.; Langwald, N.; Tomaszewska, A. [Warsaw University of Technology, Faculty of Chemistry, ul. Noakowskiego 3, 00-664 Warsaw (Poland)

    2010-09-15

    The simple reaction of trialkoxyborates with butyllithium resulted in the obtaining of new lithium borate salts: Li{l_brace}[CH{sub 3}(OCH{sub 2}CH{sub 2}){sub n}O]{sub 3}BC{sub 4}H{sub 9}{r_brace}, containing oxyethylene substituents (EO) of n=1, 2, 3 and 7. Salts of n {>=} 2 show properties of room temperature ionic liquid (RTIL) of low glass transition temperature, T{sub g} of the order from -70 to -80 C. The ionic conductivity of the salts depends on the number of EO units, the highest conductivity is shown by the salt with n = 3; in bulk its ambient temperature conductivity is 2 x 10{sup -5} S cm{sup -1} and in solution in cyclic propylene sulfite or EC/PC mixture, conductivity increases by an order of magnitude. Solid polymer electrolytes with borate salts over a wide concentration range, from 10 to 90 mol.% were obtained and characterized. Three types of polymeric matrices: poly(ethylene oxide) (PEO), poly(trimethylene carbonate) (PTMC) and two copolymers of acrylonitrile and butyl acrylate p(AN-BuA) were used in them as polymer matrices. It has been found that for systems of low salt concentration (10 mol.%) the best conducting properties were shown by solid polymer electrolytes with PEO, whereas for systems of high salt concentration, of the polymer-in-salt type, good results were achieved for PTMC as polymer matrix. (author)

  2. Fabrication of Monolithic Dye-Sensitized Solar Cell Using Ionic Liquid Electrolyte

    OpenAIRE

    Seigo Ito; Kaoru Takahashi

    2012-01-01

    To improve the durability of dye-sensitized solar cells (DSCs), monolithic DSCs with ionic liquid electrolyte were studied. Deposited by screen printing, a carbon layer was successfully fabricated that did not crack or peel when annealing was employed beforehand. Optimized electrodes exhibited photovoltaic characteristics of 0.608 V open-circuit voltage, 6.90 cm−2 mA short-circuit current, and 0.491 fill factor, yielding 2.06% power conversion efficiency. The monolithic DSC using ionic liquid...

  3. Fabrication of Monolithic Dye-Sensitized Solar Cell Using Ionic Liquid Electrolyte

    Directory of Open Access Journals (Sweden)

    Seigo Ito

    2012-01-01

    Full Text Available To improve the durability of dye-sensitized solar cells (DSCs, monolithic DSCs with ionic liquid electrolyte were studied. Deposited by screen printing, a carbon layer was successfully fabricated that did not crack or peel when annealing was employed beforehand. Optimized electrodes exhibited photovoltaic characteristics of 0.608 V open-circuit voltage, 6.90 cm−2 mA short-circuit current, and 0.491 fill factor, yielding 2.06% power conversion efficiency. The monolithic DSC using ionic liquid electrolyte was thermally durable and operated stably for 1000 h at 80°C.

  4. Reactions of CH-acids with α,β-unsaturated aldehydes in ionic liquids

    DEFF Research Database (Denmark)

    Kryshtal, G. V.; Zhdankina, G. M.; Astakhova, Irina Kira;

    2004-01-01

    - methylimidazolium hexafluorophosphate [bmim][PF 6], and in a 1-butyl-3-methylimidazolium bromide ([bmim][Br]) - benzene system. The reactions with acrolein and crotonaldehyde afforded Michael addition products, those with citral resulted in Knoevenagel addition products. Sonication increased the yields of the...... Michael adducts. The ionic liquid [bmim][PF 6] can be recovered and repeatedly used in the reactions.......Metal carbonate-catalyzed reactions of CH-acids (diethyl malonate, ethyl acetoacetate, ethyl cyanoacetate, and ethyl 2-acetyl- and 2-ethoxycarbonyl-5,9- dimethyldeca-4,8-dienoates) with α,β-unsaturated aldehydes (acrolein, crotonaldehyde, citral) were studied in an ionic liquid, 1-butyl-3...

  5. Supported Ionic Liquid Phase (SILP) Catalysis for the Production of Acetic acid by Methanol Carbonylation

    DEFF Research Database (Denmark)

    Hanning, Christopher William

    The work presented here is focused on the development of a new reaction process. It applies Supported Ionic Liquid Phase (SILP) catalysis to a specific reaction. By reacting methanol and carbon monoxide over a rhodium catalyst, acetic acid can be formed. This reaction is important on a large scale...... at the beginning with the construction of a suitable test reactor, then followed by the synthesis and testing of all the catalysts reported. A variety of nitrogen based ionic liquids were initially tested, giving good results and stability in the system. Later a number of phosphonium based salts were...

  6. A novel ionic liquids-based scrubbing process for efficient CO2 capture

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A novel alkanolamine-based ionic liquid,N-methyl-diethanolammonium tetrafluoroborate ([MDEA][BF4]),was synthesized in our laboratory.The ionic liquid-based composite solution consisting of N-methyl-diethanolamine (MDEA),[MDEA][BF4],piperazine (PZ) and H2O was investigated for CO2 capture.The optimal performance for CO2 capture was found at 45°C,1.50 MPa,probably due to a synergistic action of the reaction and the transport.No apparent corrosion was found on stainless and carbon steel with the above composite solution.This finding is very significant to the promotion of its engineering application.

  7. 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.

  8. Method and apparatus using an active ionic liquid for algae biofuel harvest and extraction

    Science.gov (United States)

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

    2012-11-06

    The invention relates to use of an active ionic liquid to dissolve algae cell walls. The ionic liquid is used to, in an energy efficient manner, dissolve and/or lyse an algae cell walls, which releases algae constituents used in the creation of energy, fuel, and/or cosmetic components. The ionic liquids include ionic salts having multiple charge centers, low, very low, and ultra low melting point ionic liquids, and combinations of ionic liquids. An algae treatment system is described, which processes wet algae in a lysing reactor, separates out algae constituent products, and optionally recovers the ionic liquid in an energy efficient manner.

  9. A novel antibody–antigen based impedimetric immunosensor for low level detection of HER2 in serum samples of breast cancer patients via modification of a gold nanoparticles decorated multiwall carbon nanotube-ionic liquid electrode

    Energy Technology Data Exchange (ETDEWEB)

    Arkan, Elham [Nano Drug Delivery Research Center, Kermanshah University of Medical Sciences, Kermanshah (Iran, Islamic Republic of); Saber, Reza [Department of Medical Nanotechnology, School of Advanced Medical Technologies, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Research Center for Science and Technology in Medicine, Imam Khomeini Hospital, Tehran (Iran, Islamic Republic of); Karimi, Ziba [Department of Chemistry, Payame Noor University, P.O. Box 19395-3697, Tehran (Iran, Islamic Republic of); Shamsipur, Mojtaba, E-mail: mshamsipur@yahoo.com [Department of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of)

    2015-05-18

    Highlights: • Design of a novel impedimetric immunosensor for detection of HER2 in serum samples. • Use of a multiwall carbon nanotube-ionic liquid electrode modified with AuNPs as a base. • Immobilization of monoclonal HER2 antibody on AuNPs/MWCILE using 1,6-hexanedithiol as a cross linker. • Achieving linear dynamic range and limit of detection of 10–110 ng mL{sup −1} and 7.4 ng mL{sup −1}, respectively. • Method development and validation and application to assay of HER2 in biological fluids. - Abstract: A highly sensitive impedimetric immunosensor based on a gold nanoparticles/multiwall carbon nanotube-ionic liquid electrode (AuNPs/MW-CILE) was developed for the determination of human epidermal growth factor receptor 2 (HER2). Gold nanoparticles were used to enhance the extent of immobilization and to retain the immunoactivity of the antibody Herceptin on the electrode. Cyclic voltammetry and electrochemical impedance spectroscopy were employed for characterization of various layers coated onto the AuNPs/MW-CILE. The impedance measurements at different steps were based on the charge transfer kinetics of the [Fe(CN){sub 6}]{sup 3−/4−} redox pair. The immobilization of antibody and the corresponding antigen–antibody interaction at the electrode surface altered the interfacial electron transfer. The interactions of antibody with various concentrations of antigen were also monitored via the change of impedance response. The results showed that the charge transfer resistance increases linearly with increasing concentrations of HER2 antigen. The linear range and limit of detection were found as 10–110 ng mL{sup −1} and 7.4 ng mL{sup −1}, respectively. The sensitivity and specificity of the immunosensor were validated. The results showed that the prepared immunosensor is a useful tool for screening of trace amounts of HER2 in serum samples of breast cancer patients.

  10. A novel antibody–antigen based impedimetric immunosensor for low level detection of HER2 in serum samples of breast cancer patients via modification of a gold nanoparticles decorated multiwall carbon nanotube-ionic liquid electrode

    International Nuclear Information System (INIS)

    Highlights: • Design of a novel impedimetric immunosensor for detection of HER2 in serum samples. • Use of a multiwall carbon nanotube-ionic liquid electrode modified with AuNPs as a base. • Immobilization of monoclonal HER2 antibody on AuNPs/MWCILE using 1,6-hexanedithiol as a cross linker. • Achieving linear dynamic range and limit of detection of 10–110 ng mL−1 and 7.4 ng mL−1, respectively. • Method development and validation and application to assay of HER2 in biological fluids. - Abstract: A highly sensitive impedimetric immunosensor based on a gold nanoparticles/multiwall carbon nanotube-ionic liquid electrode (AuNPs/MW-CILE) was developed for the determination of human epidermal growth factor receptor 2 (HER2). Gold nanoparticles were used to enhance the extent of immobilization and to retain the immunoactivity of the antibody Herceptin on the electrode. Cyclic voltammetry and electrochemical impedance spectroscopy were employed for characterization of various layers coated onto the AuNPs/MW-CILE. The impedance measurements at different steps were based on the charge transfer kinetics of the [Fe(CN)6]3−/4− redox pair. The immobilization of antibody and the corresponding antigen–antibody interaction at the electrode surface altered the interfacial electron transfer. The interactions of antibody with various concentrations of antigen were also monitored via the change of impedance response. The results showed that the charge transfer resistance increases linearly with increasing concentrations of HER2 antigen. The linear range and limit of detection were found as 10–110 ng mL−1 and 7.4 ng mL−1, respectively. The sensitivity and specificity of the immunosensor were validated. The results showed that the prepared immunosensor is a useful tool for screening of trace amounts of HER2 in serum samples of breast cancer patients

  11. Separation of thiophene from heptane with ionic liquids

    International Nuclear Information System (INIS)

    Highlights: ► The ternary (liquid + liquid) equilibria in 1-butyl-1-methylpyrrolidinium-based ILs was measured. ► High selectivity and distribution ratio for the extraction of thiophene was found. ► [BMPYR][TCM] was proposed as entrainer for the separation process. ► Extraction of sulphur-compounds from alkanes was proposed. -- Abstract: Ionic liquids (ILs) are well known novel green solvents, which can be used for removing sulfur compounds from gasoline and diesel oils. Ternary (liquid + liquid) equilibrium data are presented for mixtures of {ionic liquid (1) + thiophene (2) + heptane (3)} at T = 298.15 K and ambient pressure to analyze the performance of the ionic liquid (IL) in the extraction of thiophene from the alkanes. Three pyrrolidinium-based ionic liquids have been studied: 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate, ([BMPYR][FAP]), 1-butyl-1-methylpyrrolidinium tetracyanoborate, [BMPYR][TCB] and 1-butyl-1-methylpyrrolidinium tricyanomethanide, [BMPYR][TCM]. The results are discussed in terms of the selectivity and distribution ratio of separation of related systems. The immiscibility in the binary liquid systems of (thiophene + heptane) with all used ILs was observed. The [TCM]− anion in comparison with [TCB]− and [FAP]− anions shows much higher selectivity and slightly lower distribution ratio for extraction of thiophene. The non-random two liquid NRTL model was used successfully to correlate the experimental tie-lines and to calculate the phase composition error in mole fraction in the ternary systems. The average root mean square deviation (RMSD) of the phase composition was 0.047. The densities of [BMPYR][TCM] in temperature range from (298.15 to 348.15) K were measured. The data presented here show that the [BMPYR][TCM] ionic liquid can be used as an alternative solvent for the separation of thiophene from the hydrocarbon stream using solvent liquid–liquid extraction at ambient conditions

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

    Directory of Open Access Journals (Sweden)

    Elena Torralba-Calleja

    2013-01-01

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

  13. A New Volume-Based Approach for Predicting Thermophysical Behavior of Ionic Liquids and Ionic Liquid Crystals.

    Science.gov (United States)

    Nelyubina, Yulia V; Shaplov, Alexander S; Lozinskaya, Elena I; Buzin, Mikhail I; Vygodskii, Yakov S

    2016-08-17

    Volume-based prediction of melting points and other properties of ionic liquids (ILs) relies on empirical relations with volumes of ions in these low-melting organic salts. Here we report an accurate way to ionic volumes by Bader's partitioning of electron densities from X-ray diffraction obtained via a simple database approach. For a series of 1-tetradecyl-3-methylimidazolium salts, the volumes of different anions are found to correlate linearly with melting points; larger anions giving lower-melting ILs. The volume-based concept is transferred to ionic liquid crystals (ILs that adopt liquid crystalline mesophases, ILCs) for predicting the domain of their existence from the knowledge of their constituents. For 1-alkyl-3-methylimidazolium ILCs, linear correlations of ionic volumes with the occurrence of LC mesophase and its stability are revealed, thus paving the way to rational design of ILCs by combining suitably sized ions. PMID:27479022

  14. [Determination of solubility parameters for asymmetrical dicationic ionic liquids by inverse gas chromatography].

    Science.gov (United States)

    Wang, Jun; Yang, Xuzhao; Wu, Jinchao; Song, Hao; Zou, Wenyuan

    2015-12-01

    Inverse gas chromatographic (IGC) technology was used to determine the solubility parameters of three asymmetrical dicationic ionic liquids ([ PyC5Pi] [ NTf2]2, [MpC5Pi] [NTf2]2 and [PyC6Pi] [NTf2]2) at 343.15-363.15 K. Five alkanes were applied as test probes including octane (n-C8) , decane (n-C10), dodecane (n-C12), tetradecane (n-C14), hexadecane (n-C16). Some thermodynamic parameters were obtained by IGC data analysis, such as the specific retention volumes of the solvents (V0(g)), the molar enthalpies of sorption (ΔHs(1)), the partial molar enthalpies of mixing at infinite dilution (ΔH∞91)), the molar enthalpies of vaporization (ΔH)v)), the activity coefficients at infinite dilution (Ω∞(1)), and Flory-Huggins interaction parameters (χ∞(12)) between ionic liquids and probes. The solubility parameters (δ2) of the three dicationic ionic liquids at room temperature (298.15 K) were 28.52-32.66 (J x cm(-3)) ½. The solubility parameters (δ2) of cationic structure with 4-methyl morpholine are bigger than those of the cationic structure with pyridine. The bigger the solubility parameter (δ2) is, the more the carbon numbers of linking group of the ionic liquids are. The results are of great importance to the study of the solution behavior and the applications of ionic liquid. PMID:27097464

  15. Magnetic effervescent tablet-assisted ionic liquid dispersive liquid-liquid microextraction of selenium for speciation in foods and beverages.

    Science.gov (United States)

    Wang, Xiaojun; Wu, Long; Cao, Jiaqi; Hong, Xincheng; Ye, Rui; Chen, Weiji; Yuan, Ting

    2016-07-01

    A novel, simple and rapid method based on magnetic effervescent tablet-assisted ionic liquid dispersive liquid-liquid microextraction (MEA-IL-DLLME) followed by graphite furnace atomic absorption spectrometry (GFAAS) determination was established for the speciation of selenium in various food and beverage samples. In the procedure, a special magnetic effervescent tablet containing CO2 sources (sodium carbonate and sodium dihydrogenphosphate), ionic liquids and Fe3O4 magnetic nanoparticles (MNPs) was used to combine extractant dispersion and magnetic recovery procedures into a single step. The parameters influencing the microextraction efficiency, such as pH of the sample solution, volume of ionic liquid, amount of MNPs, concentration of the chelating agent, salt effect and matrix effect were investigated and optimised. Under the optimised conditions, the limits of detection (LODs) for Se(IV) were 0.021 μg l(-)(1) and the linear dynamic range was 0.05-5.0 μg l(-)(1). The relative standard deviation for seven replicate measurements of 1.0 μg l(-)(1) of Se(IV) was 2.9%. The accuracy of the developed method was evaluated by analysis of the standard reference materials (GBW10016 tea, GBW10017 milk powder, GBW10043 Liaoning rice, GBW10046 Henan wheat, GBW10048 celery). The proposed method was successfully applied to food and beverage samples including black tea, milk powder, mushroom, soybean, bamboo shoots, energy drink, bottled water, carbonated drink and mineral water for the speciation of Se(IV) and Se(VI) with satisfactory relative recoveries (92.0-108.1%). PMID:27181611

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  17. Ionic Liquid Catalyzed Electrolyte for Electrochemical Polyaniline Supercapacitors

    Science.gov (United States)

    Inamdar, A. I.; Im, Hyunsik; Jung, Woong; Kim, Hyungsang; Kim, Byungchul; Yu, Kook-Hyun; Kim, Jin-Sang; Hwang, Sung-Min

    2013-05-01

    The effect of different wt.% of ionic liquid "1,6-bis (trimethylammonium-1-yl) hexane tetrafluoroborate" in 0.5 M LiClO4+PC electrolyte on the supercapacitor properties of polyaniline (PANI) thin film are investigated. The PANI film is synthesized using electropolymerization of aniline in the presence of sulfuric acid. The electrochemical properties of the PANI thin film are studied by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS) measurements. The optimum amount of the ionic liquid is found to be 2 wt.% which provides better ionic conductivity of the electrolyte. The highest specific capacitance of 259 F/g is obtained using the 2 wt.% electrolyte. This capacitance remains at up to 208 F/g (80% capacity retention) after 1000 charge-discharge cycles at a current density of 0.5 mA/g. The PANI film in the 2 wt.% ionic liquid catalyzed 0.5 M LiClO4+PC electrolyte shows small electrochemical resistance, better rate performance and higher cyclability. The increased ionic conductivity of the 2 wt.% ionic liquid catalyzed electrolyte causes a reduction in resistance at the electrode/electrolyte interface, which can be useful in electrochemically-preferred power devices for better applicability.

  18. Extractive Deep Desulfurization of Liquid Fuels Using Lewis-Based Ionic Liquids

    OpenAIRE

    Swapnil A. Dharaskar; Kailas L. Wasewar; Varma, Mahesh N.; Diwakar Z. Shende

    2013-01-01

    A new class of green solvents, known as ionic liquids (ILs), has recently been the subject of intensive research on the extractive desulfurization of liquid fuels because of the limitation of traditional hydrodesulfurization method. In present work, eleven Lewis acid ionic liquids were synthesized and employed as promising extractants for deep desulfurization of the liquid fuel containing dibenzothiophene (DBT) to test the desulfurization efficiency. [Bmim]Cl/FeCl3 was the most promising ioni...

  19. Failure Mechanisms of Hollow Fiber Supported Ionic Liquid Membranes.

    Science.gov (United States)

    Zeh, Matthew; Wickramanayake, Shan; Hopkinson, David

    2016-01-01

    Hollow fiber supported ionic liquid membranes (SILMs) were tested using the bubble point method to investigate potential failure modes, including the maximum transmembrane pressure before loss of the ionic liquid from the support. Porous hollow fiber supports were fabricated with different pore morphologies using Matrimid(®) and Torlon(®) as the polymeric material and 1-hexyl-3-methylimidalzolium bis(trifluoromethylsulfonyl)imide ([C₆mim][Tf₂N]) as the ionic liquid (IL) component. Hollow fiber SILMs were tested for their maximum pressure before failure, with pressure applied either from the bore side or shell side. It was found that the membranes exhibited one or more of three different modes of failure when pressurized: liquid loss (occurring at the bubble point), rupture, and collapse. PMID:27023620

  20. Failure Mechanisms of Hollow Fiber Supported Ionic Liquid Membranes

    Directory of Open Access Journals (Sweden)

    Matthew Zeh

    2016-03-01

    Full Text Available Hollow fiber supported ionic liquid membranes (SILMs were tested using the bubble point method to investigate potential failure modes, including the maximum transmembrane pressure before loss of the ionic liquid from the support. Porous hollow fiber supports were fabricated with different pore morphologies using Matrimid® and Torlon® as the polymeric material and 1-hexyl-3-methylimidalzolium bis(trifluoromethylsulfonylimide ([C6mim][Tf2N] as the ionic liquid (IL component. Hollow fiber SILMs were tested for their maximum pressure before failure, with pressure applied either from the bore side or shell side. It was found that the membranes exhibited one or more of three different modes of failure when pressurized: liquid loss (occurring at the bubble point, rupture, and collapse.

  1. Syntheses and applications of ionic liquids as solvents and reactants : natural substances dissolution, esterification ionic tagging

    OpenAIRE

    Zhao, Bin

    2012-01-01

    The present thesis deals with the applications of ionic liquids (ILs), especially carboxylate-based ILs. The first part describes the syntheses and uses of ILs as solvents for natural compounds to dissolve cellulose and to extract betulin. The second part reveals their applications as reactants for esterification and ionic tagging. Dissolution of cellulose allows easier processing of this important biogenic feedstock. For this, ILs have been proposed. To foster understanding of the structure ...

  2. Interaction of Ionic Liquids with a Lipid Bilayer: A Biophysical Study of Ionic Liquid Cytotoxicity.

    Science.gov (United States)

    Jing, Benxin; Lan, Nan; Qiu, Jie; Zhu, Yingxi

    2016-03-17

    Ionic liquids (ILs) have been widely considered and used as "green solvents" for more than two decades. However, their ecotoxicity results have contradicted this view, as ILs, particularly hydrophobic ones, are reported to exhibit high toxicity. Yet the origin of their toxicology remains unclear. In this work, we have investigated the interaction of amphiphilic ILs with a lipid bilayer as a model cell membrane to understand their cytotoxicity at a molecular level. By employing fluorescence imaging and light and X-ray scattering techniques, we have found that amphiphilic ILs could disrupt the lipid bilayer by IL insertion, end-capping the hydrophobic edge of the lipid bilayer, and eventually disintegrating the lipid bilayer at high IL concentration. The insertion of ILs to cause the swelling of the lipid bilayer shows strong dependence on the hydrophobicity of IL cationic alky chain and anions and is strongly correlated with the reported IL cytotoxicity. PMID:26910537

  3. Unimolecular Solvolyses in Ionic Liquid: Alcohol Dual Solvent Systems

    Directory of Open Access Journals (Sweden)

    Elizabeth D. Kochly

    2016-01-01

    Full Text Available A study was undertaken of the solvolysis of pivaloyl triflate in a variety of ionic liquid:alcohol solvent mixtures. The solvolysis is a kΔ process (i.e., a process in which ionization occurs with rearrangement, and the resulting rearranged carbocation intermediate reacts with the alcohol cosolvent via two competing pathways: nucleophilic attack or elimination of a proton. Five different ionic liquids and three different alcohol cosolvents were investigated to give a total of fifteen dual solvent systems. 1H-NMR analysis was used to determine relative amounts of elimination and substitution products. It was found, not surprisingly, that increasing the bulkiness of alcohol cosolvent led to increased elimination product. The change in the amount of elimination product with increasing ionic liquid concentration, however, varied greatly between ionic liquids. These differences correlate strongly, though not completely, to the Kamlet–Taft solvatochromic parameters of the hydrogen bond donating and accepting ability of the solvent systems. An additional factor playing into these differences is the bulkiness of the ionic liquid anion.

  4. Radiation stability of some room temperature ionic liquids

    International Nuclear Information System (INIS)

    Radiation stability of some room temperature ionic liquids (RTILs) that find useful electrochemical applications in nuclear fuel cycle has been evaluated. The ionic liquids such as protonated betaine bis(trifluoromethylsulfonyl)imide (HbetNTf2), aliquat 336 (tri-n-octlymethylammonium chloride), 1-butyl-3-methylimidazolium chloride (bmimCl), 1-hexyl-3-methylimidazolium chloride (hmimCl), N-butyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BMPyNTf2) and N-methyl-N-propylpiperidinium bis(trifluoromethylsulfonyl)imide (MPPiNTf2) have been irradiated to various absorbed dose levels, up to 700 kGy. The effect of gamma radiation on these ionic liquids has been evaluated by determining the variations in the physical properties such as color, density, viscosity, refractive index and electrochemical window. The changes in density, viscosity and refractive index of these ionic liquids upon irradiation were insignificant; however, the color and electrochemical window varied significantly with increase of absorbed dose. -- Research highlights: → Room temperature ionic liquids (RTILs). → Gamma irradiation. → Determination of physical and electrochemical properties. → Minimal change in physical properties. → Large variation in electrochemical window.

  5. Novel developments in hydrogen storage, hydrogen activation and ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Doroodian, Amir

    2010-12-03

    This dissertation is divided into three chapters. Recently, metal-free hydrogen activation using phosphorous compounds has been reported in science magazine. We have investigated the interaction between hydrogen and phosphorous compounds in presence of strong Lewis acids (chapter one). A new generation of metal-free hydrogen activation, using amines and strong Lewis acids with sterically demanding nature, was already developed in our group. Shortage of high storage capacity using large substitution to improve sterical effect led us to explore the amine borane derivatives, which are explained in chapter two. Due to the high storage capacity of hydrogen in aminoborane derivatives, we have explored these materials to extend hydrogen release. These compounds store hydrogen as proton and hydride on adjacent atoms or ions. These investigations resulted in developing hydrogen storage based on ionic liquids containing methyl guanidinium cation. Then we have continued to develop ionic liquids based on methyl guanidinium cation with different anions, such as tetrafluoro borate (chapter three). We have replaced these anions with transition metal anions to investigate hydrogen bonding and catalytic activity of ionic liquids. This chapter illustrates the world of ionic liquid as a green solvent for organic, inorganic and catalytic reactions and combines the concept of catalysts and solvents based on ionic liquids. The catalytic activity is investigated particularly with respect to the interaction with CO{sub 2}. (orig.)

  6. Task-specific ionic liquid for solubilizing metal oxides.

    Science.gov (United States)

    Nockemann, Peter; Thijs, Ben; Pittois, Stijn; Thoen, Jan; Glorieux, Christ; Van Hecke, Kristof; Van Meervelt, Luc; Kirchner, Barbara; Binnemans, Koen

    2006-10-26

    Protonated betaine bis(trifluoromethylsulfonyl)imide is an ionic liquid with the ability to dissolve large quantities of metal oxides. This metal-solubilizing power is selective. Soluble are oxides of the trivalent rare earths, uranium(VI) oxide, zinc(II) oxide, cadmium(II) oxide, mercury(II) oxide, nickel(II) oxide, copper(II) oxide, palladium(II) oxide, lead(II) oxide, manganese(II) oxide, and silver(I) oxide. Insoluble or very poorly soluble are iron(III), manganese(IV), and cobalt oxides, as well as aluminum oxide and silicon dioxide. The metals can be stripped from the ionic liquid by treatment of the ionic liquid with an acidic aqueous solution. After transfer of the metal ions to the aqueous phase, the ionic liquid can be recycled for reuse. Betainium bis(trifluoromethylsulfonyl)imide forms one phase with water at high temperatures, whereas phase separation occurs below 55.5 degrees C (temperature switch behavior). The mixtures of the ionic liquid with water also show a pH-dependent phase behavior: two phases occur at low pH, whereas one phase is present under neutral or alkaline conditions. The structures, the energetics, and the charge distribution of the betaine cation and the bis(trifluoromethylsulfonyl)imide anion, as well as the cation-anion pairs, were studied by density functional theory calculations. PMID:17048916

  7. Physicochemical properties and toxicities of hydrophobicpiperidinium and pyrrolidinium ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Salminen, Justin; Papaiconomou, Nicolas; Kumar, R. Anand; Lee,Jong-Min; Kerr, John; Newman, John; Prausnitz, John M.

    2007-06-25

    Some properties are reported for hydrophobic ionic liquids (IL) containing 1-methyl-1-propyl pyrrolidinium [MPPyrro]{sup +}, 1-methyl-1-butyl pyrrolidinium [MBPyrro]{sup +}, 1-methyl-1-propyl piperidinium [MPPip]{sup +}, 1-methyl-1-butyl piperidinium [MBPip]{sup +}, 1-methyl-1-octylpyrrolidinium [MOPyrro]{sup +} and 1-methyl-1-octylpiperidinium [MOPip]{sup +} cations. These liquids provide new alternatives to pyridinium and imidazolium ILs. High thermal stability of an ionic liquid increases safety in applications like rechargeable lithium-ion batteries and other electrochemical devices. Thermal properties, ionic conductivities, viscosities, and mutual solubilities with water are reported. In addition, toxicities of selected ionic liquids have been measured using a human cancer cell-line. The ILs studied here are sparingly soluble in water but hygroscopic. We show some structure-property relationships that may help to design green solvents for specific applications. While ionic liquids are claimed to be environmentally-benign solvents, as yet few data have been published to support these claims.

  8. Electrochemical Performance of Ionic Liquid-Graphene Modified Carbon Fiber Microelectrode%离子液体-石墨烯修饰碳纤维微电极电化学性能研究

    Institute of Scientific and Technical Information of China (English)

    范跃娟; 沙翠翠; 唐旻奕; 冉菊; 程寒

    2015-01-01

    本实验制备了离子液体-石墨烯修饰碳纤维微电极,采用循环伏安法和差分脉冲伏安法测定多巴胺(DA)在该修饰电极上的电化学行为。实验结果显示,修饰后电极的稳定性和重现性明显增加,DA在修饰电极上的氧化过程受扩散控制。在5×10-7-1×10-4mol/L浓度范围内,DA在修饰电极上的氧化峰电流与其浓度呈现良好的线性关系。%[Abstract]In this paper, the carbon fiber microelectrode modified with ionic liquid-graphene composites was fabricated, the electrochemical behaviors of dopamine (DA) at the modified carbon fiber microelectrode were determined with cyclic voltammetry and differential pulse voltammetric method. The results showed that the modified electrode showed good stability and duplicability. The oxidation of DA on the surface of the modified carbon fiber microelectrode belongs to the diffusion controlled reaction. In the 20mmol/L Tris-HCl (pH7.4) buffer solution, for DA determination, the oxidation peak current and the concentration of DA showed good linear relationships.

  9. Graphene/Ionic Liquid Composite Films and Ion Exchange

    OpenAIRE

    Yufei Mo; Yunfang Wan; Alicia Chau; Fuchuan Huang

    2014-01-01

    Wettability of graphene is adjusted by the formation of various ionic surfaces combining ionic liquid (IL) self-assembly with ion exchange. The functionalized ILs were designed and synthesized with the goal of obtaining adjustable wettability. The wettability of the graphene surface bearing various anions was measured systematically. The effect of solvent systems on ion exchange ratios on the graphene surface has also been investigated. Meanwhile, the mechanical properties of the graphene/IL ...

  10. Poly(ionic liquid)/Ionic Liquid Ion-Gels with High "Free" Ionic Liquid Content: Platform Membrane Materials for CO2/Light Gas Separations.

    Science.gov (United States)

    Cowan, Matthew G; Gin, Douglas L; Noble, Richard D

    2016-04-19

    -films (ca. 100-nm-thick active layer). Traditional polymeric membrane materials are limited by a trade-off between permeability and selectivity empirically described by the "Robeson upper bound"-placing the desired membrane properties beyond reach. Therefore, the investigation of advanced and composite materials that can overcome the limitations of traditional polymeric materials is the focus of significant academic and industrial research. In particular, there has been substantial work on ionic-liquid (IL)-based materials due to their gas transport properties. This review provides an overview of our collaborative work on developing poly(ionic liquid)/ionic liquid (PIL/IL) ion-gel membrane technology. We detail developmental work on the preparation of PIL/IL composites and describe how this chemical technology was adapted to allow the roll-to-roll processing and preparation of membranes with defect-free active layers ca. 100 nm thick, CO2 permeances of over 6000 GPU, and CO2/N2 selectivity of ≥20-properties with the potential to reduce the cost of CO2 removal from coal-fired power plant flue gas to ca. $15 per ton of CO2 captured. Additionally, we examine the materials developments that have produced advanced PIL/IL composite membranes. These advancements include cross-linked PIL/IL blends, step-growth PIL/IL networks with facilitated transport groups, and PIL/IL composites with microporous additives for CO2/CH4 separations. PMID:27046045

  11. Phase diagrams of ionic liquids-based aqueous biphasic systems as a platform for extraction processes

    International Nuclear Information System (INIS)

    Highlights: • Novel ABS based in ionic liquids were determined as a platform for distinct extraction processes. • The effect of pH, IL cation core, alkyl side chain length, IL anion nature, and salt nature on the ABS formation was investigated. • The ability to form ABS increases with the pH and alkyl chain length for all systems studied. • The ILs cation core and anion nature effect on the ABS formation is dominated by the IL (hydrophobic/hydrophilic) nature. • The effect of the different salts depends of the ionic liquid nature and salt valency. - Abstract: In the past few years, ionic liquid-based aqueous biphasic systems have become the subject of considerable interest as a promising technique for the extraction and purification of several macro/biomolecules. Aiming at developing guidelines for more benign and efficient extraction processes, phase diagrams for aqueous biphasic systems composed of ionic liquids and inorganic/organic salts are here reported. Several combinations of ionic liquid families (imidazolium, pyridinium, phosphonium, quaternary ammonium and cholinium) and salts [potassium phosphate buffer (KH2PO4/K2HPO4 at pH 7), potassium citrate buffer (C6H5K3O7/C6H8O7 at pH 5, 6, 7 and 8) and potassium carbonate (K2CO3 at pH ∼13)] were evaluated to highlight the influence of the ionic liquid structure (cation core, anion and alkyl chain length), the pH and the salt nature on the formation of aqueous biphasic systems. The binodal curves and respective tie-lines reported for these systems were experimentally determined at (298 ± 1) K. In general, the ability to promote the aqueous biphasic systems formation increases with the pH and alkyl chain length. While the influence of the cation core and anion nature of the ionic liquids on their ability to form aqueous biphasic systems closely correlates with ionic liquids capacity to be hydrated by water, the effect of the different salts depends of the ionic liquid nature and salt valency

  12. (Vapor + liquid) equilibria of binary mixtures containing light alcohols and ionic liquids

    International Nuclear Information System (INIS)

    This work presents (vapor + liquid) equilibrium (VLE) of binary mixtures containing methanol or ethanol and three imidazolium based ionic liquids: 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium acetate, and 1-butyl-3-methylimidazolium hydrogen sulfate. VLE measurements were carried out over the whole range of composition between (283.15 and 298.15) K using a static apparatus. Activity coefficients γi of these solvents in the ionic liquids have been determined from the VLE data and correlated using the NRTL model. The results show that the NRTL model can be applied successfully with systems containing ionic liquids.

  13. (Vapor + liquid) equilibria of binary mixtures containing light alcohols and ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Revelli, Anne-Laure [Laboratoire de Thermodynamique des Milieux Polyphases, Nancy-Universite, 1 rue Grandville, BP 20451, 54001 Nancy (France); Mutelet, Fabrice, E-mail: mutelet@ensic.inpl-nancy.f [Laboratoire de Thermodynamique des Milieux Polyphases, Nancy-Universite, 1 rue Grandville, BP 20451, 54001 Nancy (France); Jaubert, Jean-Noel [Laboratoire de Thermodynamique des Milieux Polyphases, Nancy-Universite, 1 rue Grandville, BP 20451, 54001 Nancy (France)

    2010-02-15

    This work presents (vapor + liquid) equilibrium (VLE) of binary mixtures containing methanol or ethanol and three imidazolium based ionic liquids: 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium acetate, and 1-butyl-3-methylimidazolium hydrogen sulfate. VLE measurements were carried out over the whole range of composition between (283.15 and 298.15) K using a static apparatus. Activity coefficients gamma{sub i} of these solvents in the ionic liquids have been determined from the VLE data and correlated using the NRTL model. The results show that the NRTL model can be applied successfully with systems containing ionic liquids.

  14. (Liquid + liquid) equilibria for mixtures of dodecane and ethanol with alkylsulfate-based ionic liquids

    International Nuclear Information System (INIS)

    Highlights: • LLE data for dodecane + ethanol + 1-alkyl-imidazoluim-based ionic liquids (ILs). • ILs are [Mmim][MeSO4], [Emim][MeSO4], and [Bmim][MeSO4]. • Measurements at T = 298.15 K and 0.101 MPa, as well as at T = 313.15 K for [Mmim][MeSO4]. • Consistency of the tie-lines checked with the Othmer–Tobias and Hand equations. • Data correlated with the NRTL model. - Abstract: The ternary (liquid + liquid) equilibrium (LLE) data for mixtures of dodecane (C12H26) and ethanol with ionic liquids 1,3-dimethylimidazolium methylsulfate [Mmim][MeSO4], 1-ethyl-3-methylimidazolium methylsulfate, [Emim][MeSO4] and 1-butyl-3-methylimidazolium methylsulfate, [Bmim][MeSO4], were studied at T = 298.15 K and 0.101 MPa. The selectivity and solute distribution coefficient ratios determined from the data were used to examine the possibility of using these ionic liquids for extraction of ethanol from dodecane. The temperature dependency was investigated by measuring the LLE data for {dodecane + ethanol + [Mmim][MeSO4]} at T = 313.15 K and 0.101 MPa. The Othmer–Tobias and Hand equations were used to test the consistency of the tie-line data. The tie-line data were correlated with the Non-Random Two Liquid (NRTL) equation which provided a good model and representation for the experimental results

  15. Ionic association and interactions in aqueous methylsulfate alkyl-imidazolium-based ionic liquids

    International Nuclear Information System (INIS)

    Highlights: • Viscosity and electrical conductivity were determined in aqueous ionic liquids. • For the shorter IL the viscosity was lower and the electrical conductivity higher. • NMR and IR were used to study ionic association and interactions in aqueous ILs. • The main change in the ionic association was only observed for high water contents. • In IR, the SO3 asymmetric stretching band is a probe of structural changes. - Abstract: Several experimental techniques were used to study ionic association and interactions in aqueous [C1C2Im][MeSO4], 1-ethyl-3-methylimidazolium methylsulfate, and [C1C4Im][MeSO4], 1-butyl-3-methylimidazolium methylsulfate. Two transport properties, viscosity and electrical conductivity, were determined for these two binary mixtures. For a better assessment of the ionic association and the perturbation of water into the molecular structure of the ionic liquid, diffusion coefficients of ions and water molecules were obtained by NMR spectroscopy while molecular interactions were probed by IR spectroscopy. The comparison of the two ionic liquids shows that for the shorter alkyl chain the viscosity was lower and the electrical conductivity was higher. While the viscosity of the mixture drops already with small additions of water, the electrical conductivity of the solution is only significantly increased for high water concentrations. A maximum is observed for compositions around xwater = (0.90 to 0.95). The SO3 asymmetric stretching band of the IR spectrum can be used as a probe to observe the evolution of the structure around the anion which was mainly occurring for high concentrations of water. Several experimental techniques show than the main change in the ionic association was only observed for high water contents (water mole fraction > 0.8)

  16. The Use of Supported Acidic Ionic Liquids in Organic Synthesis

    Directory of Open Access Journals (Sweden)

    Rita Skoda-Földes

    2014-06-01

    Full Text Available Catalysts obtained by the immobilisation of acidic ionic liquids (ILs on solid supports offer several advantages compared to the use of catalytically active ILs themselves. Immobilisation may result in an increase in the number of accessible active sites of the catalyst and a reduction of the amount of the IL required. The ionic liquid films on the carrier surfaces provide a homogeneous environment for catalytic reactions but the catalyst appears macroscopically as a dry solid, so it can simply be separated from the reaction mixture. As another advantage, it can easily be applied in a continuous fixed bed reactor. In the present review the main synthetic strategies towards the preparation of supported Lewis acidic and Brønsted acidic ILs are summarised. The most important characterisation methods and structural features of the supported ionic liquids are presented. Their efficiency in catalytic reactions is discussed with special emphasis on their recyclability.

  17. Biomass Conversion in Ionic Liquids - in-situ Investigations

    DEFF Research Database (Denmark)

    Kunov-Kruse, Andreas Jonas

    Due to rising oil prices and global warming caused by CO2 emissions, there is an increased demand for new types of fuels and chemicals derived from biomass. This thesis investigates catalytic conversion of cellulose into sugars in ionic liquids and the important platform chemical 5...... activation energies suggest that the ionic liquid acts co-catalytic by stabilizing the oxocarbenium transition state. The chromium catalyzed conversion of glucose to HMF in ionic liquid 1-butyl-3-methylimidazolium chloride with CrCl3⋅6H2O and CrCl2 as catalysts was investigated. The CrCl3⋅6H2O catalyst......-30 times higher with an activation energy of 74 kJ/mol. The thesis identifies the product inhibition as a major challenge for technical utilization of chromium catalysts in biomass conversion....

  18. Single-Molecule Electrochemical Gating in Ionic Liquids

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  19. USE OF IONIC LIQUIDS FOR IMPROVEMENT OF CELLULOSIC ETHANOL PRODUCTION

    Directory of Open Access Journals (Sweden)

    Qijun Wang

    2011-02-01

    Full Text Available Cellulosic ethanol production has drawn much attention in recent years. However, there remain significant technical challenges before such production can be considered as economically feasible at an industrial scale. Among them, the efficient conversion of carbohydrates in lignocellulosic biomass into fermentable sugars is one of the most challenging technical difficulties in cellulosic ethanol production. Use of ionic liquids has opened new avenues to solve this problem by two different pathways. One is pretreatment of lignocellulosic biomass using ionic liquids to increase its enzymatic hydrolysis efficiency. The other is to transform the hydrolysis process of lignocellulosic biomass from a heterogeneous reaction system to a homogeneous one by dissolving it into ionic liquids, thus improving its hydrolysis efficiency.

  20. Magnetically rotational reactor for absorbing benzene emissions by ionic liquids

    Institute of Scientific and Technical Information of China (English)

    Yangyang; Jiang; Chen; Guo; Huizhou; Liu

    2007-01-01

    A magnetically rotational reactor (MRR) has been developed and used in absorbing benzene emissions. The MRR has a permanent magnet core and uses magnetic ionic liquid [bmim]FeCl4 as absorbent. Benzene emissions were carried by N2 into the MRR and were absorbed by the magnetic ionic liquid. The rotation of the permanent magnet core provided impetus for the agitation of the magnetic ionic liquid, enhancing mass transfer and making benzene better dispersed in the absorbent. 0.68 g benzene emissions could be absorbed by a gram of [bmim]FeCl4, 0.27 and 0.40 g/ghigher than that by [bmim]PF6 and [bmim]BF4, respectively. The absorption rate increased with increasing rotation rate of the permanent magnet.

  1. Mechanical properties and XRD of Nafion modified by 2-hydroxyethylammonium ionic liquids

    International Nuclear Information System (INIS)

    In this work, the Nafion 112 membrane impregnated with 2-hydroxyethylammonium carboxylate ionic liquids have been investigated. The used ionic liquids were 2-hydroxyethylammonium formate [HEA]F, acetate [HEA]A and lactate [HEA]L. Prepared composite membranes Nafion/ionic liquid are characterized by mechanical testing, such as tensile test and creep test. It is found that ionic liquids decrease elastic modulus and creep compliance, but do not have significant effect on the tensile strength. Also, composite membranes were studied by wide angle X-ray diffraction. All ionic liquids shift the peak maximum to the lower angle. In this work, only biodegradable ionic liquids were used for composite preparation

  2. Ionic liquid-assisted solublization for improved enzymatic esterification of phenolic acids

    DEFF Research Database (Denmark)

    Yang, Zhiyong; Guo, Zheng; Xu, Xuebing

    2012-01-01

    in a binary system, which is composed of ionic liquid tOMA•TFA (trioctylmethylammonium Trifluoroacetate) and octanol. Ionic liquid tOMA•TFA has great solubility towards most of phenolic acid. The strategy of increasing the solubility of phenolic in ionic liquid tOMA•TFA was proved to be an efficient way...... was also higher than the parallel experiment where no ionic liquid was applied for increasing solubility of DHCA. Relative high conversion of ferulic and caffeic acids was achieved when similar reactions were conducted with these two phenolic acids, and the conversion in the system containing ionic liquid...... was significant higher than the system without ionic liquid....

  3. Single Molecule Electrochemical Detection in Aqueous Solutions and Ionic Liquids.

    Science.gov (United States)

    Byers, Joshua C; Paulose Nadappuram, Binoy; Perry, David; McKelvey, Kim; Colburn, Alex W; Unwin, Patrick R

    2015-10-20

    Single molecule electrochemical detection (SMED) is an extremely challenging aspect of electroanalytical chemistry, requiring unconventional electrochemical cells and measurements. Here, SMED is reported using a "quad-probe" (four-channel probe) pipet cell, fabricated by depositing carbon pyrolytically into two diagonally opposite barrels of a laser-pulled quartz quadruple-barreled pipet and filling the open channels with electrolyte solution, and quasi-reference counter electrodes. A meniscus forms at the end of the probe covering the two working electrodes and is brought into contact with a substrate working electrode surface. In this way, a nanogap cell is produced whereby the two carbon electrodes in the pipet can be used to promote redox cycling of an individual molecule with the substrate. Anticorrelated currents generated at the substrate and tip electrodes, at particular distances (typically tens of nanometers), are consistent with the detection of single molecules. The low background noise realized in this droplet format opens up new opportunities in single molecule electrochemistry, including the use of ionic liquids, as well as aqueous solution, and the quantitative assessment and analysis of factors influencing redox cycling currents, due to a precisely known gap size. PMID:26398675

  4. Structural studies of ionic liquid-modified microemulsions.

    Science.gov (United States)

    Rojas, Oscar; Koetz, Joachim; Kosmella, Sabine; Tiersch, Brigitte; Wacker, Philipp; Kramer, Markus

    2009-05-15

    This work is focused on the influence of an ionic liquid (IL), i.e. ethyl-methylimidazolium hexylsulfate, on the spontaneous formation of microemulsions with ionic surfactants. The influence of the ionic liquid on structure formation in the optically clear phase region in water/toluene/pentanol mixtures in presence of the cationic surfactant CTAB was studied in more detail. The results show a significant increase of the transparent phase region by adding the ionic liquid. Conductometric investigations demonstrate that adding the ionic liquid can drastically reduce the droplet-droplet interactions in the L(2) phase. (1)H nuclear magnetic resonance ((1)H NMR) diffusion coefficient measurements in combination with dynamic light scattering measurements clearly show that inverse microemulsion droplets still exist, but the droplet size is decreased to 2 nm. A more detailed characterisation of the isotropic phase channel by means of conductivity measurements, dynamic light scattering (DLS), (1)H NMR and cryo-scanning electron microscopy (SEM), allows the identification of a bicontinuous sponge phase between the L(1) and L(2) phase. When the poly(ethyleneimine) is added, the isotropic phase range is reduced drastically, but the inverse microemulsion range still exists. PMID:19278685

  5. Sorption of trifluoromethane in zeolites and ionic liquid

    International Nuclear Information System (INIS)

    Highlights: • Adsorption of trifluoromethane on zeolites Na-Y, K,H-Y, and Rb,Na-Y. • Absorption of trifluoromethane in ionic liquid, [emim][Tf2N]. • Heat of adsorption of trifluoromethane on zeolites from 29 to 35 kJ · mol−1. • Type II adsorption on zeolites. • Type V phase behavior in ionic liquid. -- Abstract: Sorption isotherms for trifluoromethane (R-23) on three zeolites, Na-Y, K,H-Y, and Rb,Na-Y and ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [emim][Tf2N] have been measured at ca. 298 and 323 K, using a gravimetric microbalance. The adsorption on the zeolites reaches about 3 mol · kg−1 at 0.025 MPa and 298 K while in the ionic liquid the absorption reaches 3 mol · kg−1 at about 2.5 MPa (100 times higher pressure). Three different adsorption models (Langmuir, multi-site Langmuir, and BET equations) have been used to analyze the zeolite sorption data, with a particular interest in the heat of adsorption (−ΔH). The heat of adsorption for zeolites Na-Y, K,H-Y, and Rb,Na-Y were about 35 ± 3 kJ · mol−1, 29 ± 3 kJ · mol−1, and 34 ± 5 kJ · mol−1, respectively. These values are within the range of typical physical adsorption. According to the IUPAC classification, the zeolites exhibit Type II adsorption and according to the Scott and van Konynenburg classification the ionic liquid is predicted to be Type V phase behavior. The adsorption process on the zeolites took more time than the absorption process in the ionic liquid to reach the thermodynamic equilibrium and both processes were reversible

  6. Ionic liquids: the link to high-temperature molten salts?

    Science.gov (United States)

    El Abedin, Sherif Zein; Endres, Frank

    2007-11-01

    Due to their wide thermal windows, ionic liquids can be regarded as the missing link between aqueous/organic solutions and high-temperature molten salts. They can be employed efficiently for the coating of other metals with thin layers of tantalum, aluminum, and presumably many others at reasonable temperatures by electrochemical means. The development of ionic liquids, especially air and water stable ones, has opened the door for the electrodeposition of reactive elements such as, for example, Al, Ta, and Si, which in the past were only accessible using high-temperature molten salts or, in part, organic solvents. PMID:17521159

  7. Electrodeposition of Lithium from Lithium-Containing Solvate Ionic Liquids

    OpenAIRE

    Vanhoutte, Gijs; Brooks, Neil R.; Schaltin, Stijn; Opperdoes, Bastiaan; Van Meervelt, Luc; Locquet, Jean-Pierre; Vereecken, Philippe M.; Fransaer, Jan; Binnemans, Koen

    2014-01-01

    Lithium-containing solvate ionic liquids [Li(L)n][X], with ligands L = 1,2-dimethoxyethane (G1, monoglyme) or 1-methoxy-2-(2-methoxyethyl)ether (G2, diglyme) (with n = 1, 2 or 3) and with anions X = bis(trifluoromethylsulfonyl)imide (Tf2N–), bromide (Br–) or iodide (I–), were synthesized and used as electrolytes for the electrodeposition of lithium metal. Very high lithium-ion concentrations could be obtained, since the lithium ion is part of the cationic structure of the solvate ionic liquid...

  8. Video-microscopic observation of ionic liquid/alcohol interface and the corresponding molecular simulation study

    Science.gov (United States)

    Zhu, Peixi

    addition to 1-butyl-3-methylimidazolium tetrafluoroborate, the generalization was tested also on tetraethyl ammonium tetrafluoroborate in propylene carbonate from low to high concentrations, and on the corresponding primitive model. Such generalization helps us understand paring of ions in electrolyte solution, especially for elevated concentrations. Two cases of 1-hexyl-3-methylimidazolium tetrafluoroborate ionic liquid/n-pentanol system were studied, which are (i) liquid-liquid interface; and (ii) solution of the former in the latter. Computation of biphasic interface revealed interaction at the liquid-liquid junction, e.g., the transport of molecules from one phase to another, and lead to evaluation of diffusion coefficient that has good agreement with experimental measurement. The simulation of dilute electrolyte solution, i.e., an ionic liquid pair in n-pentanol, gives free energy change as a function of ion separation distance. The dissociation constant K was evaluated and found to be closed to experimental value that was obtained from solution conductivity measurement. The investigation of ion dynamics, especially the memory function transformed from velocity autocorrelation function, lead to the finding of dielectric friction in the system. Furthermore, precise evaluation of D gives satisfied agreement with experimental measurement from micropipette technique.

  9. Catalytic Conversion of Biomass to Fuels and Chemicals Using Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wei; Zheng, Richard; Brown, Heather; Li, Joanne; Holladay, John; Cooper, Alan; Rao, Tony

    2012-04-13

    This project provides critical innovations and fundamental understandings that enable development of an economically-viable process for catalytic conversion of biomass (sugar) to 5-hydroxymethylfurfural (HMF). A low-cost ionic liquid (Cyphos 106) is discovered for fast conversion of fructose into HMF under moderate reaction conditions without any catalyst. HMF yield from fructose is almost 100% on the carbon molar basis. Adsorbent materials and adsorption process are invented and demonstrated for separation of 99% pure HMF product and recovery of the ionic liquid from the reaction mixtures. The adsorbent material appears very stable in repeated adsorption/regeneration cycles. Novel membrane-coated adsorbent particles are made and demonstrated to achieve excellent adsorption separation performances at low pressure drops. This is very important for a practical adsorption process because ionic liquids are known of high viscosity. Nearly 100% conversion (or dissolution) of cellulose in the catalytic ionic liquid into small molecules was observed. It is promising to produce HMF, sugars and other fermentable species directly from cellulose feedstock. However, several gaps were identified and could not be resolved in this project. Reaction and separation tests at larger scales are needed to minimize impacts of incidental errors on the mass balance and to show 99.9% ionic liquid recovery. The cellulose reaction tests were troubled with poor reproducibility. Further studies on cellulose conversion in ionic liquids under better controlled conditions are necessary to delineate reaction products, dissolution kinetics, effects of mass and heat transfer in the reactor on conversion, and separation of final reaction mixtures.

  10. Extractive Deep Desulfurization of Liquid Fuels Using Lewis-Based Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Swapnil A. Dharaskar

    2013-01-01

    Full Text Available A new class of green solvents, known as ionic liquids (ILs, has recently been the subject of intensive research on the extractive desulfurization of liquid fuels because of the limitation of traditional hydrodesulfurization method. In present work, eleven Lewis acid ionic liquids were synthesized and employed as promising extractants for deep desulfurization of the liquid fuel containing dibenzothiophene (DBT to test the desulfurization efficiency. [Bmim]Cl/FeCl3 was the most promising ionic liquid and performed the best among studied ionic liquids under the same operating conditions. It can remove dibenzothiophene from the model liquid fuel in the single-stage extraction process with the maximum desulfurization efficiency of 75.6%. It was also found that [Bmim]Cl/FeCl3 may be reused without regeneration with considerable extraction efficiency of 47.3%. Huge saving on energy can be achieved if we make use of this ionic liquids behavior in process design, instead of regenerating ionic liquids after every time of extraction.

  11. Physicochemical properties of low viscous lactam based ionic liquids

    International Nuclear Information System (INIS)

    Graphical abstract: Remarkably low viscosities of butyrolactam acetate and caprolactam acetate: experimental values (symbols) and VTF equation fitting (solid lines). - Highlights: • Caprolactam and butyrolactam based novel six ionic liquids have been synthesized. • Density, viscosity and speed of sound of lactam based ionic liquids have been measured. • Remarkably low viscosity has been observed for studied lactum based ionic liquids. • Effects of alkyl chain length on anion, geometry of cation and temperature upon studied properties have been discussed. - Abstract: Lactam based ionic liquids were synthesized by an atom economization process between a lactam such as caprolactam or butyrolactam with a Brønsted acid such as formic acid, acetic acid or hexanoic acid. The density, speed of sound and viscosity were measured at atmospheric pressure and as a function of temperature from T = (293.15 to 333.15) K. The experimental density and viscosity values were fitted with linear and Vogel–Tamman–Fulcher (VTF) equations, respectively and found to be fitting well within the experimental error. Thermodynamically important derived properties such as the coefficient of thermal expansion (α) and isentropic compressibility (βs) were calculated from the experimental density and speed of sound values. Lattice potential energy (UPOT) has been calculated to understand the strength of ionic interaction between the ions and the standard entropy (So) has been estimated to assess the disorder within the fluids. The remarkably low values of viscosity of ionic liquids studied are discussed on the basis of activation energy estimated from the Arrhenius equation. Furthermore, the effect of alkyl chain length on the anion, geometry of the cation and temperature has been analysed for the properties studied

  12. Concentration and electrode material dependence of the voltammetric response of iodide on platinum, glassy carbon and boron-doped diamond in the room temperature ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide

    International Nuclear Information System (INIS)

    The electro-oxidation of iodide has been investigated as a function of concentration using steady-state microelectrode voltammetry, transient cyclic voltammetry and linear-sweep semi-integral voltammetry on platinum, glassy carbon and boron-doped diamond electrodes in the room temperature ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide. Two oxidation processes are observed on all of the investigated electrode materials, with the first being assigned to the oxidation of iodide to triiodide (confirmed by UV/visible spectroscopy) and the second being attributed to the oxidation of triiodide to iodine. Iodide oxidation is kinetically more facile on platinum compared to glassy carbon or boron-doped diamond. At elevated bulk iodide concentrations, the nucleation and growth of sparingly soluble electrogenerated iodine at the electrode surface was observed and imaged in situ using optical microscopy. The diffusion coefficient of iodide was determined to be 2.59 (±0.04) × 10−7 cm2 s−1 and independent of the bulk concentration of iodide. The steady-state iodide oxidation current measured at a platinum microelectrode was found to be a linear function of iodide concentration, as expected if there are no contributions from non-Stokesian mass-transport processes (electron hopping and/or Grotthuss-type exchange) under the investigated conditions

  13. Ionic-Liquid Based Separation of Azeotropic Mixtures

    DEFF Research Database (Denmark)

    Kulajanpeng, Kusuma; Suriyapraphadilok, Uthaiporn; Gani, Rafiqul

    2014-01-01

    stability, toxicity, and environmental impacts of the ILs. A Hildebrand solubility parameter group contribution model for ILs is highlighted to screen the miscibility of the ILs with the target solute component which was considered as a key target property to further screen the candidates from the previous......methodology for the screening of ionic liquids (ILs) as entrainers for ILs-based separation processes in binary aqueous azeotropic systems (e.g., water + ethanol and water + isopropanol) is presented. Ionic liquids as entrainers were first screened based on a combination of criteria such as...... [C1MIM][DMP]. For the final evaluation, the best candidates for aqueous systems were used as entrainers, and then the vapor-liquid equilibrium (VLE) of the ternary systems containing ILs was predicted by the Non Random Two Liquids (NRTL) model to confirm the breaking of the azeotrope. Based on...

  14. Blending ionic liquids: how physico-chemical properties change.

    Science.gov (United States)

    Castiglione, Franca; Raos, Guido; Appetecchi, Giovanni Battista; Montanino, Maria; Passerini, Stefano; Moreno, Margherita; Famulari, Antonino; Mele, Andrea

    2010-02-28

    Ionic liquids offer the opportunity of tailoring their properties by changing the chemical structure of the cation and anion. Blending of two or more liquids adds a further dimension to this "chemical space". Here we present the results of a study of three binary and one ternary mixture of the ionic liquids formed by the N-butyl-N-methylpyrrolidinium cation with bis(trifluoromethanesulfonyl) imide, bis(pentafluoroethanesulfonyl) imide and (trifluoromethanesulfonyl)(nonafluorobutanesulfonyl) imide. We have collected viscosity and NMR-based data on ionxion correlations (NOE) and diffusion (DOSY). We also attempt to establish a quantitative correlation between mixture and the corresponding pure liquid properties. We find that the binary mixture containing the two very different anions has an intriguing and somewhat anomalous behaviour. PMID:20145843

  15. Ambient Ionic Liquids Used in the Reduction ofAldehydes and Ketones

    Institute of Scientific and Technical Information of China (English)

    Dan Qian XU; Shu Ping LUO; Bao You LIU; Zhen Yuan XU; Yin Chu SHEN

    2004-01-01

    The sodium borohydride reduction of aldehydes and ketones to corresponding alcohols has been accomplished via the use of ionic liquids. The alcohols are easily obtained with excellent yields and the ionic liquid BMImBF4 could be reused.

  16. Application of ionic liquid as a reaction field of radiation chemistry

    International Nuclear Information System (INIS)

    Radiation induced polymerizations and reductions in ionic liquids are introduced in this report. Ionic liquids are suitable substitutes not only for organic solvents as media for radiation induced reactions but also enhance their reactivities. (author)

  17. How Ionic Liquid Changes Properties of Dense Polydimethylsiloxane Membrane?

    Czech Academy of Sciences Publication Activity Database

    Kohoutová, Marie; Sikora, Antonín; Hovorka, Š.; Randová, A.; Schauer, Jan; Poloncarzová, Magda; Izák, Pavel

    2010-01-01

    Roč. 14, 1-3 (2010), s. 78-82. ISSN 1944-3994 R&D Projects: GA ČR GA203/08/0465 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40500505 Keywords : pervaporation * ionic liquid * fermentation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.752, year: 2010

  18. Imidazolium ionic liquids as catalysts for precursors of epoxy materials

    Czech Academy of Sciences Publication Activity Database

    Perchacz, Magdalena; Donato, R. K.; Beneš, Hynek; Kobera, Libor; Walterová, Zuzana

    Gargnano : European Polymer Federation, 2015. s. 1. [ EPF Summer School - Polymers at Interfaces and Surfaces /7./. 17.05.2015-22.05.2015, Gargnano] R&D Projects: GA ČR(CZ) GA14-05146S Institutional support: RVO:61389013 Keywords : ionic liquid * epoxy resin * sol-gel Subject RIV: CD - Macromolecular Chemistry

  19. Finkelstein Reaction in Functionalized Crown-ether Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    Xiao Hua WANG; Han Zhi WANG; Hui LIU; Yuan KOU

    2006-01-01

    Functional crown-ether ionic liquids were used as catalytic green solvents of Finkelstein reaction of 1-bromooctane and iodide. The rate and yield of the reaction were obvious improved compared with that using crown ether in water. No free crown ether loss was observed after reaction.

  20. Ionic liquid-facilitated preparation of lignocellulosic composites

    Science.gov (United States)

    Lignocellulosic composites (LCs) were prepared by partially dissolving cotton along with steam exploded Aspen wood and burlap fabric reinforcements utilizing an ionic liquid (IL) solvent. Two methods of preparation were employed. In the first method, a controlled amount of IL was added to preassembl...

  1. Lunar Oxygen Production and Metals Extraction Using Ionic Liquids

    Science.gov (United States)

    Marone, Matthew; Paley, Mark Steven; Donovan, David N.; Karr, Laurel J.

    2009-01-01

    Initial results indicate that ionic liquids are promising media for the extraction of oxygen from lunar regolith. IL acid systems can solubilize regolith and produce water with high efficiency. IL electrolytes are effective for water electrolysis, and the spent IL acid media are capable of regeneration.

  2. IONIC LIQUID-CATALYZED ALKYLATION OF ISOBUTANE WITH 2-BUTENE

    Science.gov (United States)

    A detailed study of the alkylation of isobutane with 2-butene in ionic liquid media has been conducted using 1-alkyl-3-methylimidazolium halides?aluminum chloride encompassing various alkyl groups (butyl-, hexyl-, and octyl-) and halides (Cl, Br, and I) on its cations and anions,...

  3. Molecular Dynamics Simulations Study on Chiral Room -Temperature Ionic Liquids

    Czech Academy of Sciences Publication Activity Database

    Lísal, Martin; Chvál, Z.; Storch, Jan; Izák, Pavel; Aim, Karel

    Frankfurt : DECHEMA, 2012, P2-35. ISBN N. [European Symposium on Applied Thermodynamics - ESAT 2012 /26./. Potsdam (DE), 07.10.2012-10.10.2012] Institutional support: RVO:67985858 Keywords : ionic liquids * molecular dynamics simulations * thermodynamics properties Subject RIV: CF - Physical ; Theoretical Chemistry http://events.dechema.de/events/en/esat2012.html

  4. Recent Developments in Chemical Synthesis with Biocatalysts in Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Mahesh K. Potdar

    2015-09-01

    Full Text Available Over the past decade, a variety of ionic liquids have emerged as greener solvents for use in the chemical manufacturing industries. Their unique properties have attracted the interest of chemists worldwide to employ them as replacement for conventional solvents in a diverse range of chemical transformations including biotransformations. Biocatalysts are often regarded as green catalysts compared to conventional chemical catalysts in organic synthesis owing to their properties of low toxicity, biodegradability, excellent selectivity and good catalytic performance under mild reaction conditions. Similarly, a selected number of specific ionic liquids can be considered as greener solvents superior to organic solvents owing to their negligible vapor pressure, low flammability, low toxicity and ability to dissolve a wide range of organic and biological substances, including proteins. A combination of biocatalysts and ionic liquids thus appears to be a logical and promising opportunity for industrial use as an alternative to conventional organic chemistry processes employing organic solvents. This article provides an overview of recent developments in this field with special emphasis on the application of more sustainable enzyme-catalyzed reactions and separation processes employing ionic liquids, driven by advances in fundamental knowledge, process optimization and industrial deployment.

  5. Tunable reinforcement of epoxy-silica nanocomposites with ionic liquids

    Czech Academy of Sciences Publication Activity Database

    Donato, Ricardo Keitel; Donato, Katarzyna Zawada; Schrekker, H. S.; Matějka, Libor

    2012-01-01

    Roč. 22, č. 19 (2012), s. 9939-9948. ISSN 0959-9428 R&D Projects: GA ČR GAP108/12/1459 Grant ostatní: AV ČR(CZ) M200500903 Institutional support: RVO:61389013 Keywords : nanocomposite * ionic liquid * tensile properties Subject RIV: CD - Macromolecular Chemistry Impact factor: 5.968, year: 2011

  6. Dissolution of agro-waste in ionic liquids

    International Nuclear Information System (INIS)

    Full text: There are abundant of agro-wastes being produced in Malaysia. One of the largely produced agro wastes is the sago hampas. It is known as a strong environmental pollutant due to its cellulosic fibrous material. However, the presence of the starch, cellulose and hemicelluloses in the hampas can be converted into valuable products such as reducing sugars. Hence, this study was performed to investigate the ability of ionic liquids in hydrolysing the ligno celluloses biomass into reducing sugars. Three types of ionic liquids were used, 1-butyl-3-methylimidazolium chloride (BMIM Cl), 1-ethyl-3- methylimidazolium acetate (EMIM Ac) and 1-ethyl-3-methylimidazolium diethyl phosphate (EMIM DEP). The reaction was performed by heating the reaction mixture of sago hampas and ionic liquids at 100 degree Celsius. The concentrations of reducing sugars in the hydrolysates were determined by DNS method. Maximum concentration of reducing sugars were 0.424, 0.299, 0.260 mg/ml for BmimCl, EmimAc and EmimDEP respectively. These concluded that the selected ionic liquids were inefficient in hydrolysing the sago hampas to reducing sugars. (author)

  7. Ionic liquids and proteases: A clean alliance for semisynthesis

    Czech Academy of Sciences Publication Activity Database

    Wehofsky, N.; Wespe, Ch.; Čeřovský, Václav; Pech, A.; Hoess, E.; Rudolph, R.; Bordusa, F.

    2008-01-01

    Roč. 9, č. 9 (2008), s. 1493-1499. ISSN 1439-4227 Grant ostatní: DFG(DE) SPP1191; DFG(DE) SFB610 Institutional research plan: CEZ:AV0Z40550506 Keywords : chemoenzymatic synthesis * ionic liquids * peptides * proteases * substrate mimetics Subject RIV: CC - Organic Chemistry Impact factor: 3.322, year: 2008

  8. A novel cellulose hydrogel prepared from its ionic liquid solution

    Institute of Scientific and Technical Information of China (English)

    LI Lu; LIN ZhangBi; YANG Xiao; WAN ZhenZhen; CUI ShuXun

    2009-01-01

    A novel cellulose hydrogel is prepared by regenerating cellulose from its ionic liquid solution. The transparency cellulose hydrogel presents a good chemical stability and an acceptable mechanical property. This non-toxic cellulose hydrogel should be biocompatibie and may be useful in the future as a biomaterial.

  9. Electroreduction of Copper Dichloride Powder to Copper Nanoparticles in an Ionic Liquid

    OpenAIRE

    2014-01-01

    There were a large number of ionic liquids electrodeposition reported in the literature; but were still in the laboratory stage some problems in the practical application of electrodeposition remain such as easily reacted with moisture in the air (AlCl3 ionic liquid), high cost, and corrosive (dialkylimidazolium cation and BF4−, PF6− ionic liquid). In addition to the above shortcomings, low solubility of many metal salts in ionic liquids limits the practical application. In order to solve the...

  10. On the role of cyclic unsaturated additives on the behaviour of lithium metal electrodes in ionic liquid electrolytes

    International Nuclear Information System (INIS)

    Three cyclic vinyl based additives, based respectively on oxygen, sulphur and fluorine, are tested for their ability to improve the cycling of lithium in a hostile ionic liquid medium. Oxygen based vinylene carbonate is found to offer the best protection of the lithium metal whilst allowing very consistent lithium cycling to occur. The vinylene carbonate based system under study is, however, imperfect. Lithium metal is deposited in a dendritic morphology, and vinylene carbonate is rapidly consumed during lithium cycling if it is present in a small quantity. Our results suggest that ionic liquid systems critically relying on a small amount of additive to protect a lithium electrode are not viable for long cycle life secondary batteries. It is suggested that an ionic liquid which itself is lithium metal compatible be used instead.

  11. Effect of Electric Field Alignment on Morphology and Ionic Conductivity of Polymerized Ionic Liquid Block Copolymers

    Science.gov (United States)

    Sharick, Sharon; Nykaza, Jacob; Elabd, Yossef A.; Winey, Karen I.

    2014-03-01

    Polymerized ionic liquid (PIL) block copolymers are appealing for numerous electrochemical applications, including solid polymer electrolyte membranes for batteries and anion exchange membranes for fuel cells. The extent to which the reduced segmental motion caused by the non-conducting polymer segments and grain boundaries between block copolymer microdomains are detrimental to ionic conductivity is unknown. Increased long-range morphological order and connectivity of PIL microdomains are key to understanding the ion transport mechanism and may improve the ionic conductivity of PIL block copolymers. The effect of electric field on the morphology and ionic conductivity of poly(styrene- b-1-[2-(methacryloyloxy)ethyl]-3-butylimidazolium-bis(trifluoromethanesulfonyl)imide)) (PS- b-PMEBIm-TFSI) will be discussed as a function of microdomain orientation. Electric field is used to increase the perpendicular orientation of ion-conducting pathways with respect to the electrodes. The morphology and ionic conductivity were characterized by small-angle X-ray scattering and electrochemical impedance spectroscopy, respectively. The ionic conductivity of unoriented and oriented block copolymers will be compared to the PIL homopolymer, PMEBIm-TFSI, using the Sax and Ottino model.

  12. Hydroxycarbonylation of olefins and alcohols in ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Lapidus, A.L.; Eliseev, O.L.; Bondarenko, T.N.; Stepin, N.N. [Russian Academy of Sciences, Moscow (Russian Federation). N.D. Zelinsky Institute of Organic Chemistry

    2006-07-01

    Palladium-catalysed hydroxycarbonylation of olefins and alcohols proceeds in ionic liquid media. Terminal and internal olefins, cyclohexene, styrene, methanol, ethanol, n-butanol, cyclohexanol, benzyl alcohol and 1-phenylethanol were tested as substrates for the reaction. A number of molten salts were applied as a reaction medium and tetrabutylammonium bromide (m.p. 103 C) seemed to be the best. Carbon monoxide pressure of 2 MPa and reaction temperature of 110 C are suitable conditions to furnish the reaction in 2 hours in the presence of palladium acetate as a precursor. Triphenylphosphine added as a ligand reduces reaction rate. The critical role of counter anion in molten salt was also recognised. Yield of acids decreased in the order: Br{sup -} > Cl{sup -} > BF{sub 4} {approx}PF{sub 6}{sup -}. A two-route reaction scheme is proposed to explain the regularities of styrene and 1-phenylethanol hydroxycarbonylation. The catalytic system can be used repeatedly by simple extraction of products with diethyl ether. Nine cycles were carried out without loss of activity. (orig.)

  13. Enhanced performance of dicationic ionic liquid electrolytes by organic solvents

    International Nuclear Information System (INIS)

    The use of dicationic ionic liquid (DIL) electrolytes in supercapacitors is impeded by the slow dynamics of DILs, whereas the addition of organic solvents into DIL electrolytes improves ion transport and then enhances the power density of supercapacitors. In this work, the influences of organic solvents on the conductivity of DILs and the electrical double layer (EDL) of DIL-based supercapacitors are investigated using classical molecular dynamics simulation. Two types of organic solvents, acetonitrile (ACN) and propylene carbonate (PC), were used to explore the effects of different organic solvents on the EDL structure and capacitance of DIL/organic solvent-based supercapacitors. Firstly, it was found that the conductivity of DIL electrolytes was greatly enhanced in the presence of the organic solvent ACN. Secondly, a stronger adsorption of PC on graphite results in different EDL structures formed by DIL/ACN and DIL/PC electrolytes. The expulsion of co-ions from EDLs was observed in DIL/organic solvent electrolytes rather than neat DILs and this feature is more evident in DIL/PC. Furthermore, the bell-shaped differential capacitance–electric potential curve was not essentially changed by the presence of organic solvents. Comparing DIL/organic solvent electrolytes with neat DILs, the capacitance is slightly increased by organic solvents, which is in agreement with experimental observation. (paper)

  14. Solubilities of isobutane and cyclopropane in ionic liquids

    International Nuclear Information System (INIS)

    Graphical abstract: Henry’s constants for isobutane and cyclopropane in [HMIM][Tf2N] and [P(14)666][TMPP]. - Highlights: • Solubilities of isobutane and cyclopropane in two ionic liquids were reported. • Solubilities were measured from T = (302 to 344) K and from (0.03 to 1.16) MPa. • The effects of temperature and pressure on the solubilities were investigated. • Solubilities of hydrocarbons in [HMIM][Tf2N] and [P(14)666][TMPP] were compared. • A modified Krichevsky–Kasarnovsky equation was used to model experimental data. - Abstract: In this work, we presented the solubilities of isobutane and cyclopropane in 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([HMIM][Tf2N]) and trihexyl tetradecylphosphonium bis(2,4,4-trimethylpentyl) phosphinate ([P(14)666][TMPP]) from T = (302 to 344) K up to 1.16 MPa. Henry’s constants for isobutane and cyclopropane in [HMIM][Tf2N] and [P(14)666][TMPP] were calculated from experimental results. Solubilities of isobutane and cyclopropane in [HMIM][Tf2N] are apparently smaller than those in [P(14)666][TMPP]. The effects of temperature, pressure and the number of carbon atoms in the hydrocarbons on the solubility were investigated in detail. A modified Krichevsky–Kasarnovsky equation was successfully applied to correlate the experimental results. The mean absolute relative deviations and the maximum absolute relative deviations are less than (2.4 and 4.6)%, respectively

  15. Prediction of liquid−liquid equilibria of (aromatic + aliphatic + ionic liquid) systems using the Cosmo-SAC model

    International Nuclear Information System (INIS)

    Highlights: ► Aromatic/aliphatic hydrocarbons separation by ionic liquids. ► Cosmo-SAC thermodynamic model for prediction of LLE by quantum chemical calculations. ► Predictions successful for some ionic liquids. ► Correlation by single parameter for other ionic liquids. ► Preliminary screening of additional ionic liquids for aromatic/aliphatic separation. - Abstract: The extraction of aromatic hydrocarbons from aliphatic hydrocarbons is an important problem. This process can be used to enhance the capacity of ethylene crackers by prior removal of aromatics that cannot be cracked. Ionic liquids have been investigated extensively for liquid–liquid extraction of aromatics from aliphatics. The choice of a suitable ionic liquid may be made by measuring liquid−liquid equilibria. However, the large number of ionic liquids, formed by the various cation and anion combinations, makes the experimental measurements expensive and time consuming. Hence, a predictive thermodynamic model called Cosmo-SAC that uses quantum chemical calculations for calculating liquid−liquid equilibria has been evaluated. A priori predictions are accurate for some ionic liquids and inaccurate for some ionic liquids. However, it has been shown that even when a priori predictions are inaccurate, the data can be correlated using a single parameter that is characteristic of the ionic liquid and accurate predictions can be made for additional aromatic/aliphatic combinations for the same ionic liquid. A comparison with the NRTL and UNIQUAC models has also been carried out. In addition, a preliminary screening of ionic liquids for aromatic/aliphatic separations has been carried out using the Cosmo-SAC model. Finally, the “Cosmo” files for eight cations and sixteen anions corresponding to 128 potential ionic liquids have been provided for the use of the general scientific community to predict any thermodynamic equilibria involving ionic liquids without the use of any molecular modeling

  16. Enhanced ionic liquid mobility induced by confinement in 1D CNT membranes

    Science.gov (United States)

    Berrod, Q.; Ferdeghini, F.; Judeinstein, P.; Genevaz, N.; Ramos, R.; Fournier, A.; Dijon, J.; Ollivier, J.; Rols, S.; Yu, D.; Mole, R. A.; Zanotti, J.-M.

    2016-04-01

    Water confined within carbon nanotubes (CNT) exhibits tremendous enhanced transport properties. Here, we extend this result to ionic liquids (IL) confined in vertically aligned CNT membranes. Under confinement, the IL self-diffusion coefficient is increased by a factor 3 compared to its bulk reference. This could lead to high power battery separators.Water confined within carbon nanotubes (CNT) exhibits tremendous enhanced transport properties. Here, we extend this result to ionic liquids (IL) confined in vertically aligned CNT membranes. Under confinement, the IL self-diffusion coefficient is increased by a factor 3 compared to its bulk reference. This could lead to high power battery separators. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01445c

  17. Ionic liquid supported acid-catalysed esterification of lauric acid

    International Nuclear Information System (INIS)

    Ionic Liquid (IL) based on 1-n-butyl-3-methylimidazolium bis(trifluoro methylsulfonyl)imide (BMI.NTf2) under acidic condition was used as catalyst for the esterification reaction of fatty acid. Various acids namely sulphuric acid, perchloric acid, p-toulene sulphonic acid and various chloride salts such as zinc chloride (ZnCl2) and iron (III) chloride (FeCl3) immobilized in ionic liquid BMI.NTf2 gave acidic ILs. These acidic ILs were tested as catalysts for esterification reactions. Esterification of alcohol (methanol) with fatty acid (lauric acid) using ionic liquid BMI.NTf2 combined with H2SO4 (BMI.NTf2(H2SO4)) gave high activity (>85 %) and selectivity (100 %) observed over a period of 2 hours reaction with reaction temperature 70 degree Celsius. The ester became easily separated due to IL forming biphasic with product after the reaction where ester accumulated as the upper phase and IL with water produced after reaction at lower phase. Catalytic activities comparison also be studied between acidic ionic liquid BMI.NTf2 with acidic ionic liquid ChCl.2ZnCl2 and conventional acid catalyst. These ILs were characterised by using FTIR, NMR and TGA. Results from FTIR were showed no significant difference between ILs with ILs in acidic condition. The TGA curve show BMI.NTf2 thermals decomposition is ≥400 degree Celsius but when BMI.NTf2 combination with H2SO4, TGA curve show weight loss increase and becomes unstable. The advantages of ILs as catalyst are clean process and green chemistry due to its behaviour such as non-volatile, no loss of solvent through evaporation and reduced environmentally impact. This ILs-catalyst system can be recycle for further reaction. (author)

  18. Liquid-liquid extraction of U(VI) using malonamide in room temperature ionic liquid

    International Nuclear Information System (INIS)

    The extraction behavior of U(VI) from nitric acid medium by a solution of N,N-dimethyl-N,Ndiphenylmalonamide (DMPMA) in the ionic liquid, BmimPF6, was studied. The extractability was measured as a function of various parameters such as kinetics, phase ratio, the concentration of DMPMA, nitric acid and sodium nitrate, alkyl chain length of ionic liquid. The extractability from 5 M nitric acid by 0.35 M DMPMA/BmimPF6 as found to be almost 100 %. Slope analysis of the experimental data suggests that the probable molecular structure of the extraction species is [UO2NO3(DMPMA)2]+, and the mechanism likely occurs by a cation exchange mode. (author)

  19. Phase equilibria and surfactant behavior of fluorinated ionic liquids with water

    International Nuclear Information System (INIS)

    Highlights: • Phase equilibria of water and fluorinated ionic liquids. • Critical micelle concentrations of fluorinated ionic liquids. • Size of the aggregates using Dynamic Light Scattering. - Abstract: This work studies the phase equilibria and surfactant behavior of fluorinated ionic liquids (FILs) containing fluorinated chains equal to four carbons with water. The knowledge about the phase behavior is crucial for the applications of these novel FILs with tuneable properties. The phase equilibria of the binary mixtures FILs with water were studied at atmospheric pressure in a temperature range from (298.15 to 353.15) K. In this study, FILs containing ammonium, pyrrolidinium and imidazolium cations and the perfluorobutanesulfonate anion were included. The Non-Random Two Liquid (NRTL) thermodynamic model was successfully applied to rationalize the phase behavior of the binary (water + FILs) mixtures. Furthermore, the critical micelle concentrations (CMCs) of these FILs, which present cations and/or anions with surfactant properties were also performed at T = 298.15 K by measurements of the ionic conductivity. Finally, the Dynamic Light Scattering (DLS) was used with aim to determinate the size of the aggregates of these FILs in water

  20. Anomalous extraction behavior of Americium (III) in some diglycolamide isomers present in ionic liquid medium

    International Nuclear Information System (INIS)

    The alkyl derivatives of diglycolamide (DGA) such as N,N,N',N'-tetraoctyldiglycolamide (TODGA), N,N,N',N'-tetraethylhexyldiglycolamide (TEHDGA) and N,N-diethylhexyl- N',N'-dioctyldiglycolamide (DEHDODGA) are chain isomers differing only in the arrangement of carbon chain of the alkyl group. The extraction behavior of Am(III) in the solution of these diglycolamides in ionic liquid medium was studied as a function of concentration of nitric acid and diglycolamide. The results were compared with those obtained in a molecular diluent, n-dodecane. The extraction of Am(III) in ionic liquid medium increased in the order TEHDGA < TODGA < DEHDODGA, which was different from the customary trend of TEHDGA < DEHDODGA < TODGA obtained in n-DD. The anomaly observed in ionic liquid medium was probed by IR spectroscopy and measurement of stoichiometry. The stoichiometry of Am:DGA in each case was different and that exhibited a strong influence on the observed extraction trend. The unprotonated fraction of DGA, assessed from FTIR measurements, increased in the order TEHDGA < TODGA < DEHDODGA, which seems to be responsible for the observed anomalous extraction trend in DEHDODGA in ionic liquid medium. (author)

  1. Immobilization of Pd(Ⅱ) Catalysts for Cyclopropanation in Ionic Liquid

    Institute of Scientific and Technical Information of China (English)

    YANG,Fan(杨帆); ZHANG,Yang-Ming(张仰明); QIU,Wen-Wei(仇文卫); TANG,Jie(汤杰); HE,Ming-Yuan(何鸣元)

    2002-01-01

    Cyclopropanation of styrene with ethyl diazoacetate catalyzed by Pd(Ⅱ)in ionic liquid [omim] [BF4] was investigated. Palladium catalysts can be effectively immobilized in ionic liquid.The catalysts PdCl2 and cyclopalladated complex 2 contained in ionic liquid could be recycled for 6 and 7 times, respectively, without losing the efficiency.

  2. Thermomorphic phase separation in ionic liquid-organic liquid systems - conductivity and spectroscopic characterization

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Berg, Rolf W.;

    2005-01-01

    Electrical conductivity, FT-Raman and NMR measurements are demonstrated as useful tools to probe and determine phase behavior of thermomorphic ionic liquid-organic liquid systems. To illustrate the methods, consecutive conductivity measurements of a thermomorphic methoxyethoxyethyl......-imidazolium ionic liquid/1-hexanol system are performed in the temperature interval 25-80 degrees C using a specially constructed double-electrode cell. In addition, FT-Raman and H-1-NMR spectroscopic studies performed on the phase-separable system in the same temperature interval confirm the mutual solubility of...... the components in the system, the liquid-liquid equilibrium phase diagram of the binary mixture, and signify the importance of hydrogen bonding between the ionic liquid and the hydroxyl group of the alcohol....

  3. Supercritical fluid chromatography with ionic liquid stationary phases: Practical experience with determination of analyte distribution constants

    Czech Academy of Sciences Publication Activity Database

    Planeta, Josef; Karásek, Pavel; Roth, Michal

    Pardubice: Univerzita Pardubice, 2005 - (Jandera, P.). s. 186-187 ISBN 80-7194-771-7. [International Symposium on Separation Sciences (ISSS 2005) /11./. 12.09.2005-14.09.2005, Pardubice] R&D Projects: GA AV ČR IAA4031301; GA AV ČR KJB400310504; GA ČR GA203/05/2106 Keywords : ionic liquid * supecritical carbon dioxide * capillary-column chromatography Subject RIV: CB - Analytical Chemistry, Separation

  4. Ionic Liquid-Assisted Synthesis of a NiO/CNTs Composite and Its Electrochemical Capacitance

    OpenAIRE

    Yitong Chen; Xiangjun Lu; Bo Gao

    2014-01-01

    A novel solid-state method has been developed for synthesizing nickel oxide (NiO)/carbon nanotubes (CNTs) composite using an ionic liquid (IL, 1-butyl-3-methylimidazolium chloride) as the reaction medium. Ultraviolet-visible (UV-vis) absorbance spectroscopy, infrared spectroscopy (IR), and scanning electron microscopy (SEM) were employed to investigate the structure, morphology, and formation mechanism of the synthesized sample. The results demonstrated that the IL is effective for dispersing...

  5. High-Pressure Phase Equilibria in Systems Containing CO2 and Ionic Liquids

    Czech Academy of Sciences Publication Activity Database

    Sedláková, Zuzana; Wagner, Zdeněk; Aim, Karel

    Catalogue : Zagreb Inventors Association, 2011, s. 131. [International Invention Show (silver medal awarded) /36./. Zagreb (HR), 09.11.2011-12.11.2011] R&D Projects: GA ČR GP203/09/P141; GA AV ČR IAA400720710 Institutional research plan: CEZ:AV0Z40720504 Keywords : high pressure * ionic liquid * carbon dioxide Subject RIV: CF - Physical ; Theoretical Chemistry

  6. Progress in Separation of Gases by Permeation and Liquids by Pervaporation Using Ionic Liquids: A Review

    Czech Academy of Sciences Publication Activity Database

    Kárászová, Magda; Kačírková, Marie; Friess, K.; Izák, Pavel

    2014-01-01

    Roč. 132, AUG 20 (2014), s. 93-101. ISSN 1383-5866 R&D Projects: GA ČR GA14-12695S; GA ČR GAP106/10/1194; GA MŠk LH14006; GA MŠk(CZ) LD14094 Institutional support: RVO:67985858 Keywords : gas separations * ionic liquid * supported ionic liquid membranes Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.091, year: 2014

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

    OpenAIRE

    Karmakar, A.; Ghosh, A.

    2014-01-01

    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 th...

  8. Force microscopy of layering and friction in an ionic liquid.

    Science.gov (United States)

    Hoth, Judith; Hausen, Florian; Müser, Martin H; Bennewitz, Roland

    2014-07-16

    The mechanical properties of the ionic liquid 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl) trifluorophosphate ([Py1,4][FAP]) in confinement between a SiOx and a Au(1 1 1) surface are investigated by means of atomic force microscopy (AFM) under electrochemical control. Up to 12 layers of ion pairs can be detected through force measurements while approaching the tip of the AFM to the surface. The particular shape of the force versus distance curve is explained by a model for the interaction between tip, gold surface and ionic liquid, which assumes an exponentially decaying oscillatory force originating from bulk liquid density correlations. Jumps in the tip-sample distance upon approach correspond to jumps of the compliant force sensor between branches of the oscillatory force curve. Frictional force between the laterally moving tip and the surface is detected only after partial penetration of the last double layer between tip and surface. PMID:24919549

  9. Force microscopy of layering and friction in an ionic liquid

    Science.gov (United States)

    Hoth, Judith; Hausen, Florian; Müser, Martin H.; Bennewitz, Roland

    2014-07-01

    The mechanical properties of the ionic liquid 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl) trifluorophosphate ([Py1,4][FAP]) in confinement between a SiOx and a Au(1 1 1) surface are investigated by means of atomic force microscopy (AFM) under electrochemical control. Up to 12 layers of ion pairs can be detected through force measurements while approaching the tip of the AFM to the surface. The particular shape of the force versus distance curve is explained by a model for the interaction between tip, gold surface and ionic liquid, which assumes an exponentially decaying oscillatory force originating from bulk liquid density correlations. Jumps in the tip-sample distance upon approach correspond to jumps of the compliant force sensor between branches of the oscillatory force curve. Frictional force between the laterally moving tip and the surface is detected only after partial penetration of the last double layer between tip and surface.

  10. Force microscopy of layering and friction in an ionic liquid

    International Nuclear Information System (INIS)

    The mechanical properties of the ionic liquid 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl) trifluorophosphate ([Py1,4][FAP]) in confinement between a SiOx and a Au(1 1 1) surface are investigated by means of atomic force microscopy (AFM) under electrochemical control. Up to 12 layers of ion pairs can be detected through force measurements while approaching the tip of the AFM to the surface. The particular shape of the force versus distance curve is explained by a model for the interaction between tip, gold surface and ionic liquid, which assumes an exponentially decaying oscillatory force originating from bulk liquid density correlations. Jumps in the tip–sample distance upon approach correspond to jumps of the compliant force sensor between branches of the oscillatory force curve. Frictional force between the laterally moving tip and the surface is detected only after partial penetration of the last double layer between tip and surface. (paper)

  11. 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. PMID:22446050

  12. Acrylate Functionalized Tetraalkylammonium Salts with Ionic Liquid Properties

    Directory of Open Access Journals (Sweden)

    Silvia Janietz

    2012-05-01

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

  13. Morphological and electromechanical characterization of ionic liquid/Nafion polymer composites

    Science.gov (United States)

    Bennett, Matthew; Leo, Donald

    2005-05-01

    Ionic liquids have shown promise as replacements for water in ionic polymer transducers. Ionic liquids are non-volatile and have a larger electrochemical stability window than water. Therefore, transducers employing ionic liquids can be operated for long periods of time in air and can be actuated with higher voltages. Furthermore, transducers based on ionic liquids do not exhibit the characteristic back relaxation that is common with water-swollen materials. However, the physics of transduction in the ionic liquid-swollen materials is not well understood. In this paper, the morphology of Nafion/ionic liquid composites is characterized using small-angle X-ray scattering (SAXS). The electromechanical transduction behavior of the composites is also investigated. For this testing, five different counterions and two ionic liquids are used. The results reveal that both the morphology and transduction performance of the composites is affected by the identity of the ionic liquid, the cation, and the swelling level of ionic liquid within the membrane. Specifically, speed of response is found to be lower for the membranes that were exchanged with the smaller lithium and potassium ions. The response speed is also found to increase with increased content of ionic liquid. Furthermore, for the two ionic liquids studied, the actuators swollen with the less viscous ionic liquid exhibited a slower response. The slower speed of response corresponds to less contrast between the ionically conductive phase and the inert phase of the polymer. This suggests that disruption of the clustered morphology in the ionic liquid-swollen membranes as compared to water-swollen membranes attenuates ion mobility within the polymer. This attenuation is attributed to swelling of the non-conductive phase by the ionic liquids.

  14. Ionic liquid based dispersive liquid-liquid microextraction of aromatic amines in water samples

    Institute of Scientific and Technical Information of China (English)

    Yun Chang Fan; Zheng Liang Hu; Mei Lan Chen; Chao Shen Tu; Yan Zhu

    2008-01-01

    In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction (IL-DLLME) was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4-aminobiphenyl in aqueous matrices. After extraction the ionic liquid (IL) phase was injected directly into the high performance liquid chromatography (HPLC) system for determination. Some parameters that might affect the extraction efficiency were optimized. Under the optimum conditions, good linear relationship, sensitivity and reproducibility were obtained. The limits of detection (LOD, S/N = 3) for the four analytes were in the range of 0.45-2.6 μg L-1. The relative standard deviations (R.S.D., n = 6) were in the range of 6.2-9.8%. This method was applied for the analysis of the real water samples. The recoveries ranged from 93.4 to 106.4%. The main advantages of the method are high speed, high recovery, good repeatability and volatile organic solvent-free.

  15. Printing graphene-carbon nanotube-ionic liquid gel on graphene paper: Towards flexible electrodes with efficient loading of PtAu alloy nanoparticles for electrochemical sensing of blood glucose.

    Science.gov (United States)

    He, Wenshan; Sun, Yimin; Xi, Jiangbo; Abdurhman, Abduraouf Alamer Mohamed; Ren, Jinghua; Duan, Hongwei

    2016-01-15

    The increasing demands for portable, wearable, and implantable sensing devices have stimulated growing interest in innovative electrode materials. In this work, we have demonstrated that printing a conductive ink formulated by blending three-dimensional (3D) porous graphene-carbon nanotube (CNT) assembly with ionic liquid (IL) on two-dimensional (2D) graphene paper (GP), leads to a freestanding GP supported graphene-CNT-IL nanocomposite (graphene-CNT-IL/GP). The incorporation of highly conductive CNTs into graphene assembly effectively increases its surface area and improves its electrical and mechanical properties. The graphene-CNT-IL/GP, as freestanding and flexible substrates, allows for efficient loading of PtAu alloy nanoparticles by means of ultrasonic-electrochemical deposition. Owing to the synergistic effect of PtAu alloy nanoparticles, 3D porous graphene-CNT scaffold, IL binder and 2D flexible GP substrate, the resultant lightweight nanohybrid paper electrode exhibits excellent sensing performances in nonenzymatic electrochemical detection of glucose in terms of sensitivity, selectivity, reproducibility and mechanical properties. PMID:26709299

  16. Ionic liquid-assisted multiwalled carbon nanotube-dispersive micro-solid phase extraction for sensitive determination of inorganic As species in garlic samples by electrothermal atomic absorption spectrometry

    Science.gov (United States)

    Grijalba, Alexander Castro; Escudero, Leticia B.; Wuilloud, Rodolfo G.

    2015-08-01

    A highly sensitive dispersive micro-solid phase extraction (D-μ-SPE) method combining an ionic liquid (IL) and multi-walled carbon nanotubes (MWCNTs) for inorganic As species (As(III) and As(V)) species separation and determination in garlic samples by electrothermal atomic absorption spectrometry (ETAAS) was developed. Trihexyl(tetradecil)phosphonium chloride IL was used to form an ion pair with the arsenomolybdate complex obtained by reaction of As(V) with molybdate ion. Afterwards, 1.0 mg of MWCNTs was dispersed for As(V) extraction and the supernatant was separated by centrifugation. MWCNTs were re-dispersed with tetradecyltrimethylammonium bromide surfactant and ultrasound followed by direct injection into the graphite furnace of ETAAS for As determination. Pyrolysis and atomization conditions were carefully studied for complete decomposition of MWCNTs and IL matrices. Under optimum conditions, an extraction efficiency of 100% and a preconcentration factor of 70 were obtained with 5 mL of garlic extract. The detection limit was 7.1 ng L- 1 and the relative standard deviations (RSDs) for six replicate measurements at 5 μg L- 1 of As were 5.4% and 4.8% for As(III) and As(V), respectively. The proposed D-μ-SPE method allowed the efficient separation and determination of inorganic As species in a complex matrix such as garlic extract.

  17. Trivalent europium speciation in a room-temperature ionic liquid

    International Nuclear Information System (INIS)

    Since the nuclear industry is playing an important role in the power production field, a relevant number of problems have been revealed. Indeed, high-level radioactive long-lived nuclear wastes present a real difficulty for nuclear wastes management. Minor actinides, which compose most of these wastes, will be radioactive for several thousands of years. For eventual disposal deep underground, their reprocessing needs to be optimized. The extraction processes used industrially to separate actinides and lanthanides from other metal species characterizing the spent nuclear fuel produce, nevertheless, enormous quantities of contaminated liquid wastes directly issued from the liquid/liquid extraction step. During the last decade, some room-temperature ionic liquid have been studied and integrated into industrial processes. The interest on this class of solvent came out from their 'green' properties (non volatile, non flammable, recyclable, etc...), but also from the variability of their physico-chemical properties (stability, hydrophobicity, viscosity) as a function of the RTIL chemical composition. Indeed, it has been shown that classical chemical industrial processes could be transferred into those media, even more improved, while a certain number of difficulties arising from using traditional solvent can be avoided. In this respect, it could be promising to investigate the ability to use room-temperature ionic liquid into the spent nuclear fuel reprocessing field. The aim of this thesis is to test the ability of the specific ionic liquid bumimTf2N to allow trivalent europium extraction. The choice of this metal is based on the chemical analogy with trivalent minor actinides Curium and Americium which are contributing the greatest part of the long-lived high-level radioactive wastes. Handling these elements needs to be very cautious for the safety and radioprotection aspect. Moreover, europium is a very sensitive luminescent probe to its environment even at the

  18. Ionic Liquids: Radiation Chemistry, Solvation Dynamics and Reactivity Patterns

    International Nuclear Information System (INIS)

    Ionic liquids (ILs) are a rapidly expanding family of condensed-phase media with important applications in energy production, nuclear fuel and waste processing, improving the efficiency and safety of industrial chemical processes, and pollution prevention. ILs are generally nonvolatile, noncombustible, highly conductive, recyclable and capable of dissolving a wide variety of materials. They are finding new uses in chemical synthesis, catalysis, separations chemistry, electrochemistry and other areas. Ionic liquids have dramatically different properties compared to conventional molecular solvents, and they provide a new and unusual environment to test our theoretical understanding of charge transfer and other reactions. We are interested in how IL properties influence physical and dynamical processes that determine the stability and lifetimes of reactive intermediates and thereby affect the courses of chemical reactions and product distributions. Successful use of ionic liquids in radiation-filled environments, where their safety advantages could be significant, requires an understanding of ionic liquid radiation chemistry. For example, characterizing the primary steps of IL radiolysis will reveal radiolytic degradation pathways and suggest ways to prevent them or mitigate their effects on the properties of the material. An understanding of ionic liquid radiation chemistry will also facilitate pulse radiolysis studies of general chemical reactivity in ILs, which will aid in the development of applications listed above. Very early in our radiolysis studies it became evident that slow solvation dynamics of the excess electron in ILs (which vary over a wide viscosity range) increases the importance of pre-solvated electron reactivity and consequently alters product distributions. Parallel studies of IL solvation phenomena using coumarin-153 dynamic Stokes shifts and polarization anisotropy decay rates are done to compare with electron solvation studies and to evaluate

  19. Ionic liquids: radiation chemistry, solvation dynamics and reactivity patterns

    International Nuclear Information System (INIS)

    Ionic liquids (ILs) are a rapidly expanding family of condensed-phase media with important applications in energy production, nuclear fuel and waste processing, improving the efficiency and safety of industrial chemical processes, and pollution prevention. ILs are nonvolatile, noncombustible, highly conductive, recyclable and capable of dissolving a wide variety of materials. They are finding new uses in chemical synthesis, catalysis, separations chemistry, electrochemistry and other areas. Ionic liquids have dramatically different properties compared to conventional molecular solvents, and they provide a new and unusual environment to test our theoretical understanding of charge transfer and other reactions. We are interested in how IL properties influence physical and dynamical processes that determine the stability and lifetimes of reactive intermediates and thereby affect the courses of chemical reactions and product distributions. Successful use of ionic liquids in radiation-filled environments, where their safety advantages could be significant, requires an understanding of ionic liquid radiation chemistry. For example, characterizing the primary steps of IL radiolysis will reveal radiolytic degradation pathways and suggest ways to prevent them or mitigate their effects on the properties of the material. An understanding of ionic liquid radiation chemistry will also facilitate pulse radiolysis studies of general chemical reactivity in ILs, which will aid in the development of energy production, chemical industry and environmental applications. Pulse radiolysis of [R4N][NTf2] [R4N][N(CN)2], and [R4P][N(CN)2] ionic liquids produces solvated electrons that absorb over a broad range in the near infrared and persisting for hundreds of nanoseconds. Systematic cation variation shows that solvated electron's spectroscopic properties depend strongly on the lattice structure of the ionic liquid. Very early in our radiolysis studies it became evident that slow solvation

  20. Solubility of gases in 1-alkyl-3methylimidazolium alkyl sulfate ionic liquids: Experimental determination and modeling

    International Nuclear Information System (INIS)

    Highlights: ► The solubility of CO2, CH4 and C2H6 in [emim][EtSO4] is measured with a magnetic suspension balance. ► New data and literature results have been modeled with a Group Contribution equation of state. ► A specific group definition is required to model data of ionic liquids with a [MeSO4] anion. ► Deviations between model and experiments are lower than 10% in most cases. ► Deviations of 34% are observed in the case of the solubility of ethane in the ionic liquid. -- Abstract: The solubility of different gases (carbon dioxide, methane, ethane, carbon monoxide and hydrogen) in ionic liquids with an alkyl sulfate anion has been modeled with the Group Contribution equation of state developed by Skjold-Jørgensen. New gas solubility measurements have been carried out with a high pressure magnetic suspension balance in order to cover pressure and temperature ranges not considered in previous studies and to obtain more experimental information for the correlation of parameters of the equation of state. New solubility measurements include the solubility of carbon dioxide in 1-ethyl 3-methyl imidazolium ethyl sulfate [emim][EtSO4] at temperatures of 298 K and 348 K and pressures ranging from 0.3 MPa to 6.5 MPa, the solubility of methane in [emim][EtSO4] at a temperature of 293 K and pressures ranging from 0.2 MPa to 10.2 MPa, and the solubility of ethane in [emim][EtSO4] at temperatures of 323 K and 350 K and pressures ranging from 0.2 MPa to 4 MPa. Results show that the Group Contribution equation of state can be used to describe the solubility of gases in alkyl sulfate ionic liquids as well as infinite dilution coefficients of alkanes in the ionic liquids, with average deviations between experiments and calculations ranging from 1% to 10% in the case of mixtures with CO2, CO, CH4 and H2 with the alkyl sulfate ionic liquids to up to 34% in the case of the solubility of ethane in [emim][EtSO4

  1. Can Ionic Liquids Be Used As Templating Agents For Controlled Design of Uranium-Containing Nanomaterials?

    Energy Technology Data Exchange (ETDEWEB)

    Visser, A.; Bridges, N.; Tosten, M.

    2013-04-09

    Nanostructured uranium oxides have been prepared in ionic liquids as templating agents. Using the ionic liquids as reaction media for inorganic nanomaterials takes advantage of the pre-organized structure of the ionic liquids which in turn controls the morphology of the inorganic nanomaterials. Variation of ionic liquid cation structure was investigated to determine the impact on the uranium oxide morphologies. For two ionic liquid cations, increasing the alkyl chain length increases the aspect ratio of the resulting nanostructured oxides. Understanding the resulting metal oxide morphologies could enhance fuel stability and design.

  2. Superfluorinated Ionic Liquid Crystals Based on Supramolecular, Halogen-Bonded Anions

    OpenAIRE

    Cavallo, Gabriella; Terraneo, Giancarlo; Monfredini, Alessandro; Saccone, Marco; Priimagi, Arri; Pilati, Tullio; Resnati, Giuseppe; Metrangolo, Pierangelo; Bruce, Duncan W

    2016-01-01

    Unconventional ionic liquid crystals in which the liquid crystallinity is enabled by halogen-bonded supramolecular anions [CnF2n+1-I···I···I-CnF2n+1]- are reported. The material system is unique in many ways, demonstrating for the first time 1)ionic, halogen-bonded liquid crystals, and 2)imidazolium-based ionic liquid crystals in which the occurrence of liquid crystallinity is not driven by the alkyl chains of the cation.

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

    OpenAIRE

    Narcisa Marangoci; Rodinel Ardeleanu; Laura Ursu; Constanta Ibanescu; Maricel Danu; Mariana Pinteala; Simionescu, Bogdan C.

    2012-01-01

    An ionic liquid based on polydimethylsiloxane with imidazolium salt brushes was synthesized as a good solvent for β-cyclodextrin-polydimethylsiloxane rotaxane. As expected the PDMS-Im/Br ionic liquid had a liquid-like non-Newtonian behavior with rheological parameters dependent on frequency and temperature. The addition of rotaxane to the ionic liquid strengthened the non-Newtonian character of the sample and a type of stable liquid-like network was formed due to the contribution of weak...

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

    OpenAIRE

    Marangoci, Narcisa; Ardeleanu, Rodinel; Ursu, Laura; Ibanescu, Constanta; Danu, Maricel; Pinteala, Mariana; Simionescu, Bogdan C.

    2012-01-01

    An ionic liquid based on polydimethylsiloxane with imidazolium salt brushes was synthesized as a good solvent for β-cyclodextrin-polydimethylsiloxane rotaxane. As expected the PDMS-Im/Br ionic liquid had a liquid-like non-Newtonian behavior with rheological parameters dependent on frequency and temperature. The addition of rotaxane to the ionic liquid strengthened the non-Newtonian character of the sample and a type of stable liquid-like network was formed due to the contribution of weak ioni...

  5. Ionic selectivity of liquid dialkyl phthalate membranes

    International Nuclear Information System (INIS)

    Potentials of liquid dialkyl phthalate membranes have been studied. It is shown that they possess a sufficiently high selectivity to Cs2+, UO22+ ions. The method is suggested to clarify the actual role of softener and presupposed electrode-active addition in film electrodes. It is shown that selectivity of the known in literature uranyl film electrode on the basis of dioctyl sulfoxide (DOSO) is due to the softener-dialkyl phthalate, and not to DOSO, as it was previously considered

  6. Ionic Conductivity and Gas Permeability of Polymerized Ionic Liquid Block Copolymer Membranes

    Science.gov (United States)

    Evans, Christopher; Sanoja, Gabriel; Schneider, Yanika; Modestino, Miguel; Segalman, Rachel; Joint CenterArtificial Photosynthesis Team

    2014-03-01

    Polymer membranes for many energy applications, such as solar-to-hydrogen fuel production, require ionic conductivity while acting as gas diffusion barriers. We have synthesized a diblock copolymer consisting of poly(styrene-block-(4-(2-methacrylamidoethyl)-imidazolium trifluoroacetate) by treating poly(styrene-block-histamine methacrylamide) (PS- b-PHMA) with trifluoroacetic acid. The PS block serves as the structural support while the imidazolium derivative is an ion conducting polymerized ionic liquid (PIL). Small angle X-ray scattering and transmission electron microscopy demonstrate that the block copolymer self-assembles into well-ordered nanostructures, with lamellae and hexagonally packed cylindrical morphologies. The ionic conductivities of the PS-b-PHMA materials were as high as 2 x 10-4 S/cm while an order of magnitude increase in conductivity was observed upon conversion to PS-b-PIL. The ionic conductivity of the PS-b-PIL increased by a factor of ~ 4 up to 1.2 x 10-3 S/cm as the PIL domain size increased from 20 to 40 nm. These insights allow for the rational design of high performance ion conducting membranes with even greater conductivities via precise morphological control. Additionally, the role of thermal annealing on the ionic conductivity and gas permeability of copolymer membranes was investigated.

  7. Polymer--Ionic liquid Electrolytes for Electrochemical Capacitors

    Science.gov (United States)

    Ketabi, Sanaz

    Polymer electrolyte, comprised of ionic conductors, polymer matrix, and additives, is one of the key components that control the performance of solid flexible electrochemical capacitors (ECs). Ionic liquids (ILs) are highly promising ionic conductors for next generation polymer electrolytes due to their excellent electrochemical and thermal stability. Fluorinated ILs are the most commonly applied in polymer-IL electrolytes. Although possessing high conductivity, these ILs have low environmental favorability. The aim of this work was to develop environmentally benign polymer-ILs for both electrochemical double layer capacitors (EDLCs) and pseudocapacitors, and to provide insights into the influence of constituent materials on the ion conduction mechanism and the structural stability of the polymer-IL electrolytes. Solid polymer electrolytes composed of poly(ethylene oxide) (PEO) and 1-ethyl-3-methylimidazolium hydrogen sulfate (EMIHSO4) were investigated for ECs. The material system was optimized to achieve the two criteria for high performance polymer-ILs: high ionic conductivity and highly amorphous structure. Thermal and structural analyses revealed that EMIHSO4 acted as an ionic conductor and a plasticizer that substantially decreased the crystallinity of PEO. Two types of inorganic nanofillers were incorporated into these polymer electrolytes. The effects of SiO2 and TiO2 nanofillers on ionic conductivity, crystallinity, and dielectric properties of PEO-EMIHSO 4 were studied over a temperature range from -10 °C and 80 °C. Using an electrochemical capacitor model, impedance (complex capacitance) and dielectric analyses were performed to understand the ionic conduction process with and without fillers in both semi crystalline and amorphous states of the polymer electrolytes. Despite their different nanostructures, both SiO2 and TiO2 promoted an amorphous structure in PEO-EMIHSO 4 and increased the ionic conductivity 2-fold. While in the amorphous state, the

  8. Solubilities of some gases in four immidazolium-based ionic liquids

    International Nuclear Information System (INIS)

    Graphical abstract: Experimental apparatus based on the synthetic-volumetric method for measuring solubilities of gases in liquids. Highlights: • We constructed an apparatus for measuring solubilities of sparingly-soluble gases. • We measured solubilities of five gases in four immidazolium-based ionic liquids. • We calculated Henry’s constants for gases in the ionic liquids studied in this work. -- Abstract: The synthetic-volumetric method is used for rapidly measuring solubilities of sparingly-soluble gases in monoethylene glycol and in four ionic liquids. Known molar quantities of solute and solvent are charged into an equilibrium vessel. Measured quantities at equilibrium include: temperature, pressure, quantities of fluids, and volumes of the gas and liquid phases in the equilibrium vessel. These measurements enable calculation of equilibrium compositions using material balances. No sampling or chemical analyses are required. Solubilities are reported for carbon dioxide, krypton, oxygen, and hydrogen in monoethylene glycol, l-n-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4], l-n-butyl-3-methylimidazolium hexafluorophosphate [BMIM][PF6], 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [EMIM][Tf2N], or 1-ethyl-3-methylimidazolium acetate [EMIM][AC]. Solubilities were measured over the temperature range (298 to 355) K and for pressures up to about 7 MPa using two different pieces of equipment, both based on the volumetric method: a low-pressure glass apparatus and a high-pressure stainless-steel apparatus. Special emphasis is given to experimental reliability to assure consistent data

  9. Thermoreversible (Ionic-Liquid-Based) Aqueous Biphasic Systems

    Science.gov (United States)

    Passos, Helena; Luís, Andreia; Coutinho, João A. P.; Freire, Mara G.

    2016-02-01

    The ability to induce reversible phase transitions between homogeneous solutions and biphasic liquid-liquid systems, at pre-defined and suitable operating temperatures, is of crucial relevance in the design of separation processes. Ionic-liquid-based aqueous biphasic systems (IL-based ABS) have demonstrated superior performance as alternative extraction platforms, and their thermoreversible behaviour is here disclosed by the use of protic ILs. The applicability of the temperature-induced phase switching is further demonstrated with the complete extraction of two value-added proteins, achieved in a single-step. It is shown that these temperature-induced mono(bi)phasic systems are significantly more versatile than classical liquid-liquid systems which are constrained by their critical temperatures. IL-based ABS allow to work in a wide range of temperatures and compositions which can be tailored to fit the requirements of a given separation process.

  10. Freezing of liquid alkali metals as screened ionic plasmas

    International Nuclear Information System (INIS)

    The relationship between Wigner crystallization of the classical ionic plasma and the liquid-solid transition of alkali metals is examined within the density wave theory of freezing. Freezing of the classical plasma on a rigid neutralizing background into the bcc structure is first re-evaluated, in view of recent progress in the determination of its thermodynamic functions by simulation and of the known difficulties of the theory relating to the order parameter at the (200) star of reciprocal lattice vectors. Freezing into the fcc structure is also considered in this context and found to be unfavoured. On allowing for long-wavelength deformability of the background, the ensuing appearance of a volume change on freezing into the bcc structure is accompanied by reduced stability of the fluid phase and by an increase in the entropy of melting. Freezing of alkali metals into the bcc structure is next evaluated, taking their ionic pair structure as that of an ionic plasma reference fluid screened by conduction electrons and asking that the correct ionic coupling strength at liquid-solid coexistence should be approximately reproduced. The ensuring values of the volume and entropy changes across the phase transition, as estimated from the theory by two alternative routes, are in reasonable agreement with experiment. The order parameters of the phase transition, excepting the (200) one, conform rather closely to a Gaussian behaviour and yield a Lindemann ratio in reasonable agreement with the empirical value for melting of bcc crystals. It is suggested that ionic ordering at the (200) star in the metal may be (i) assisted by medium range ordering in the conduction electrons, as indicated by differences in X-ray and neutron diffraction intensities from the liquid, and/or (ii) quite small in the hot bcc solid. Such a possible premelting behaviour of bcc metals should be worth testing experimentally by diffraction. (author). 48 refs, 1 fig., 1 tab

  11. 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.

  12. Performance of solid state supercapacitors based on polymer electrolytes containing different ionic liquids

    Science.gov (United States)

    Tiruye, Girum Ayalneh; Muñoz-Torrero, David; Palma, Jesus; Anderson, Marc; Marcilla, Rebeca

    2016-09-01

    Four Ionic Liquid based Polymer Electrolytes (IL-b-PE) were prepared by blending a Polymeric Ionic Liquid, Poly(diallyldimethylammonium) bis(trifluoromethanesulfonyl)imide (PILTFSI), with four different ionic liquids: 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14TFSI) (IL-b-PE1), 1-butyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide (PYR14FSI) (IL-b-PE2), 1-(2-hydroxy ethyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (HEMimTFSI) (IL-b-PE3), and 1-Butyl-1-methylpyrrolidinium dicyanamide, (PYR14DCA) (IL-b-PE4). Physicochemical properties of IL-b-PE such as ionic conductivity, thermal and electrochemical stability were found to be dependent on the IL properties. For instance, ionic conductivity was significantly higher for IL-b-PE2 and IL-b-PE4 containing IL with small size anions (FSI and DCA) than IL-b-PE1 and IL-b-PE3 bearing IL with bigger anion (TFSI). On the other hand, wider electrochemical stability window (ESW) was found for IL-b-PE1 and IL-b-PE2 having ILs with electrochemically stable pyrrolidinium cation and FSI and TFSI anions. Solid state Supercapacitors (SCs) were assembled with activated carbon electrodes and their electrochemical performance was correlated with the polymer electrolyte properties. Best performance was obtained with SC having IL-b-PE2 that exhibited a good compromise between ionic conductivity and electrochemical window. Specific capacitance (Cam), real energy (Ereal) & real power densities (Preal) as high as 150 F g-1, 36 Wh kg-1 & 1170 W kg-1 were found at operating voltage of 3.5 V.

  13. Ionic liquid-induced synthesis of selenium nanoparticles

    International Nuclear Information System (INIS)

    A simple wet chemical method has been used to synthesize selenium nanoparticles by the reaction of ionic liquid with sodium selenosulphate, a selenium precursor, in the presence of polyvinyl alcohol stabilizer, in aqueous medium. The method is capable of producing spherical selenium nanoparticles in the size range of 76-150 nm under ambient conditions. This is a first report on the production of nano-selenium assisted by an ionic liquid. The synthesized nanoparticles can be separated easily from the aqueous sol by a high-speed centrifuge machine, and can be re-dispersed in an aqueous medium. The synthesized selenium nanoparticles have been characterized by X-ray diffraction, energy dispersive X-ray analysis, differential scanning calorimetry and transmission electron microscopy techniques.

  14. 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.

  15. Ionic-Liquid Based Separation of Azeotropic Mixtures

    DEFF Research Database (Denmark)

    Kulajanpeng, Kusuma; Suriyapraphadilok, Uthaiporn; Gani, Rafiqul

    2014-01-01

    methodology for the screening of ionic liquids (ILs) as entrainers for ILs-based separation processes in binary aqueous azeotropic systems (e.g., water + ethanol and water + isopropanol) is presented. Ionic liquids as entrainers were first screened based on a combination of criteria such as...... stability, toxicity, and environmental impacts of the ILs. A Hildebrand solubility parameter group contribution model for ILs is highlighted to screen the miscibility of the ILs with the target solute component which was considered as a key target property to further screen the candidates from the previous...... minimum concentration of the ILs required to break the given azeotrope, the best ILs as entrainers for water + ethanol and water + isopropanol azeotropic mixtures were [C1MIM][DMP] and [C2MIM][N(CN)2], respectively....

  16. Synthesis and Characterization of Tetramethylethylenediamine-Based Hypergolic Ionic Liquids

    Science.gov (United States)

    Fei, Teng; Cai, Huiwu; Zhang, Yanqiang; Liu, Long; Zhang, Suojiang

    2016-04-01

    Four energetic salts (including two ionic liquids) based on 2-(dimethylamino)-N,N,N-trimethylethanaminium and N,N‧-dialkyl-N,N,N‧,N‧-tetramethylethane-1,2-diaminium was prepared and characterized by 1H- and 13C-NMR, infrared and Raman spectroscopies, and elemental analysis. Their physicochemical properties such as melting and decomposition temperatures, density, viscosity, heat of formation, detonation performance, and specific impulse were measured or calculated. With thermal stability up to 200°C, the resulting ionic liquids show densities from 1.02 to 1.19 g cm-3 and heats of formation from 85.1 to 154.4 kJ mol-1. Moreover, 2-(dimethylamino)-N,N,N-trimethylethanaminium dicyanamide is hypergolic with the oxidizer (100% HNO3) and exhibits potential as a green fuel for bipropellants.

  17. Betaine and Carnitine Derivatives as Herbicidal Ionic Liquids.

    Science.gov (United States)

    Pernak, Juliusz; Niemczak, Michał; Chrzanowski, Łukasz; Ławniczak, Łukasz; Fochtman, Przemysław; Marcinkowska, Katarzyna; Praczyk, Tadeusz

    2016-08-16

    This study focused on the synthesis and subsequent characterization of herbicidal ionic liquids based on betaine and carnitine, two derivatives of amino acids, which were used as cations. Four commonly used herbicides (2,4-D, MCPA, MCPP and Dicamba) were used as anions in simple (single anion) and oligomeric (two anions) salts. The obtained salts were subjected to analyzes regarding physicochemical properties (density, viscosity, refractive index, thermal decomposition profiles and solubility) as well as evaluation of their herbicidal activity under greenhouse and field conditions, toxicity towards rats and biodegradability. The obtained results suggest that the synthesized herbicidal ionic liquids displayed low toxicity (classified as category 4 compounds) and showed similar or improved efficacy against weed compared to reference herbicides. The highest increase was observed during field trials for salts containing 2,4-D as the anion, which also exhibited the highest biodegradability (>75 %). PMID:27374836

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

    Directory of Open Access Journals (Sweden)

    A. Fainleib

    2016-09-01

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

  19. Fabrication of Polyacrylonitrile Hollow Fiber Membranes from Ionic Liquid Solutions

    KAUST Repository

    Kim, Dooli

    2015-10-08

    The interest in green processes and products has increased to reduce the negative impact of many industrial processes to the environment. Solvents, which play a crucial role in the fabrication of membranes, need to be replaced by sustainable and less toxic solvent alternatives for commonly used polymers. The purpose of this study is the fabrication of greener hollow fiber membranes based on polyacrylonitrile (PAN), substituting dimethylformamide (DMF) by less toxic mixtures of ionic liquids (IL) and dimethylsulfoxide (DMSO). A thermodynamic analysis was conducted, estimating the Gibbs free energy of mixing to find the most convenient solution compositions. Hollow fiber membranes were manufactured and optimized. As a result, a uniform pattern and high porosity were observed in the inner surface of the membranes prepared from the ionic liquid solutions. The membranes were coated with a polyamide layer by interfacial polymerization the hollow fiber membranes were applied in forward osmosis experiments by using sucrose solutions as draw solution.

  20. Antibacterial activities of fluorescent nano assembled triphenylamine phosphonium ionic liquids.

    Science.gov (United States)

    Brunel, Frédéric; Lautard, Christelle; Garzino, Frédéric; Giorgio, Suzanne; Raimundo, Jean M; Bolla, Jean M; Camplo, Michel

    2016-08-01

    Staphylococcus aureus, a Gram positive coccal bacterium is a major cause of nosocomial infection. We report the synthesis of new triphenylamine phosphonium ionic liquids which are able to self-assemble into multiwall nanoassemblies and to reveal a strong bactericidal activity (MIC=0.5mg/L) for Gram positive bacteria (including resistant strains) comparable to that of standard antibiotics. Time kill, metabolism and fluorescence confocal microscopy studies show a quasi-instantaneously penetration of the nanoassemblies inside the bacteria resulting of a rapid blocking (30min) of their proliferation. As confirmed by rezasurin reduction monitoring, these compounds strongly affect the bacterial metabolism and a Gram positive versus Gram negative selectivity is clearly observed. These fluorescent phosphonium ionic liquid might constitute a useful tool for both translocation studies and to tackle infectious diseases related to the field of implantology. PMID:27287371