• Title/Summary/Keyword: Ionic liquid

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Physical and Electrochemical Properties of Polyaniline-Ionic Liquid Composite (폴리아닐린-이온성 액체 복합체의 물리적전기화학적 특성)

  • Bang, Joo-Yong;Jeong, Woo-Sung;Park, Hyung-Soon;Chung, Kyung-Ho;Nath, Narayan Chandra Deb;Lee, Jae-Joon;Cha, Eun-Hee;Lee, Jae-Kwan
    • Journal of the Korean Electrochemical Society
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    • v.13 no.3
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    • pp.181-185
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    • 2010
  • Polyaniline-ionic liquid composite was prepared and investigated its physical and electrochemical properties. The quasi-solidification was presented in imidazolium-based ionic liquid (1-methly-3-propylimidazolium iodide, PMI-I) containing above 30 wt% of polyaniline (emeraldine base), which exhibited around 80% decrease of conductivity compared to pristine ionic liquid, resulting in fibril structure trough ${\pi}-{\pi}$ self-assembled of imidazolium aromatic ring of ionic liquid on polyaniline framework.

Quasi-Solid-State Polymer Electrolytes Based on a Polymeric Ionic Liquid with High Ionic Conductivity and Enhanced Stability

  • Jeon, Nawon;Jo, Sung-Geun;Kim, Sang-Hyung;Park, Myung-Soo;Kim, Dong-Won
    • Journal of Electrochemical Science and Technology
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    • v.8 no.3
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    • pp.257-264
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    • 2017
  • A polymeric ionic liquid, poly(1-methyl 3-(2-acryloyloxypropyl) imidazolium iodide) (PMAPII), was synthesized as a single-iodide-ion-conducting polymer and employed in a gel polymer electrolyte. Gel polymer electrolytes prepared from iodine, 4-tert-butylpyridine, ${\gamma}$-butyrolactone, and PMAPII were applied in quasi-solid-state dye-sensitized solar cells (DSSCs). The addition of 16 wt.% PMAPII provided the most favorable environment, striking a compromise between the iodide ion concentration and the ionic mobility, which resulted in the highest conversion efficiency of the resulting DSSCs. The quasi-solid-state DSSC assembled with the optimized gel polymer electrolyte exhibited a relatively high conversion efficiency of 7.67% under AM 1.5 illumination at $100mA\;cm^{-2}$ and better stability than that of the DSSC with a liquid electrolyte.

Deep Desulfurization of Fuels by Heteropolyanion-Based Ionic Liquid

  • Li, Jinlei;Hu, Bing;Hu, Chuanqun
    • Bulletin of the Korean Chemical Society
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    • v.34 no.1
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    • pp.225-230
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    • 2013
  • A new heteropolyanion-based ionic ($[Hmim]_5PMo_{10}V_2O_{40}$) was synthesized by the reaction of molybdovanadophosphoric acid ($H_5PMo_{10}O_{40}$) with N-methylimidazole. [$[Hmim]_5PMo_{10}V_2O_{40}$ showed a high catalytic activity in the oxidative desulfurization of sulfur-containing compounds in 1-methylimidazolium tetrafluoroborate ($[Hmim]BF_4$) ionic liquid using 30% aqueous $H_2O_2$ as the oxidant. The catalytic system was of high activity, simplified workup and flexible recyclability. The catalytic oxidation reactivity of sulfur-containing compounds decreased in the order dibenzothiophene (DBT) > 4,6-dimethyldibenzothiophene (4,6-DMDBT) > benzothiophene (BT). The influences of various parameters including reaction time (t) and temperature (T), catalyst dosage, and oxidant to sulfur molar ratio n(O)/n(S) on the desulfurization of model oil were investigated in details. 99.1% of DBT conversion in the model oil was achieved at atmospheric pressure under the optimal conditions: n(O)/n(S) = 4:1, $60^{\circ}C$, 100 min and molar ratio of catalyst to sulfur of 0.062. The ionic liquid can be recycled six times without significant decrease in activity.

Electrochemical Characterization of Lithium Polyelectrolyte Based on Ionic Liquid

  • Cha, E.-H.;Lim, S.-A.;Kim, D.-W.;Choi, N.-S.
    • Journal of the Korean Electrochemical Society
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    • v.12 no.3
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    • pp.271-275
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    • 2009
  • Five novel lithium polyelectrolyte-ionic liquid systems, using poly (lithium 2-acrylamido-2-methyl propanesulfonate; PAMPSLi) were prepared and their electrochemical properties were measured. The ionic conductivity of the PAMPSLi/1-ethyl-3-methylimidazolium tricyano methanide (emImTCM) system was exhibited high conductivity (1.28 $\times$ $10^{-3}$ $S/cm^{-1}$). The high conductivity and low viscosity of PAMPSLi/emImTCM system is due to the high flexibility of imidazolium cation and dissociation of lithium cation from the polymer chains. The PAMPSLi/N,N-dimethyl-N-propyl-Nbutylammonium tricyanomethanide ($N_{1134}TCM$) and PAMPSLi/N, N-dimethyl-N-propyl-N-butylammonium dicyanamide ($N_{1134}DCA$) systems showed fairly high conductivity (6.3 $\times$ $10^{-4}$ $S/cm^{-1}$, 6.0 $\times$ 10.4 S/cm.1). PAMPSLi/Trihexyl (tetradecyl) phosphonium bis (trifluoromethane sulfonyl) amide ($P_{66614}TFSA$) exhibited low conductivity (2.22 $\times$ $10^{-5}$ $Scm^{-1}$) and thermally stable over 400$^{\circ}C$.

Structural Analysis of Conductive Polypyrroles Synthesized in an Ionic Liquid

  • Song, Eun-Ah;Jung, Woo-Gwang;Ihm, Dae-Woo;Kim, Jin-Yeol
    • Bulletin of the Korean Chemical Society
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    • v.30 no.5
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    • pp.1009-1011
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    • 2009
  • Nano-structured conducting polypyrroles were synthesized in the ionic liquids (ILs) based on 1-alkyl-3-methylimidazolium family with tetrachloroferrate as an anion ($C_n\;mim\;[FeCl_4]\;with\;n\;=\;4,\;8,\;and\;12$). The polypyrrole nanostructures synthesized in ILs were formed as spherical shapes. For ionic liquids with alkyl side chain length $C_4,\;C_4\;mim\;[FeCl_4]$, the size of particles was ranged around 60-nm with a relatively narrow size distribution. As the length of alkyl chain increases, the particle sizes become larger and their distributions become wider. The self-assembled local structures in the solvent ionic liquids are likely to serve as templates of highly organized nano-structured polymers. The length of the alkyl chain in ionic liquids seems to affect these local structures.

Poly (vinyl acetate)-Ionic Liquids Membranes for $CO_2$ Capture (이산화탄소 포집용 폴리비닐아세테이트-이온성액체 막)

  • Lee, Sang-Jin;Choe, Su-Hyeon;Baek, Il-Hyeon
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 2010.04a
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    • pp.199-199
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    • 2010
  • Polymeric membranes have been widely used to separate gas mixtures, such as $O_2/N_2,\;CO_2/CH_4,\;CO_2/N_2$, and olefin/paraffin. The permeation selectivity is the ratio between composition ratio at the permeate side and composition ratio at the feed side. In addition, the permeation selectivity is a product of solubility selectivity and diffusivity selectivity. We present a novel idea and describe its experimental result, which was achieved by preparing polymer gel films that included a room temperature ionic liquid (RTIL) in a polymer matrix. It is known that $CO_2$ can dissolve easily in imidazolium-based RTILs. We prepared polymer-ionic liquid gel films using an ionic liquid, 1-ethyl-3-methylimidazolium acetate ([emim] acetate, C-tri) and a host polymer, poly (vinyl acetate) (PVAc, Aldrich).

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Aromatic Fluorination by Decomposition of Triazenes in Ionic Liquids

  • Chu, Chan-Kook;Kim, Jong-Hwan;Kim, Dong-Wook;Chung, Kyoo-Hyun;Katzenellenbogen, John A.;Chi, Dae-Yoon
    • Bulletin of the Korean Chemical Society
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    • v.26 no.4
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    • pp.599-602
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    • 2005
  • The aromatic fluorination method involving the acid-catalyzed decomposition of a triazene in an ionic liquid is a very convenient and efficient way to prepare a variety of aromatic fluorides in a lab-scale. It should be particularly useful for the preparation aryl fluorides substituted with electron withdrawing substituents. Fluorination of triazene 1 (1.0 mmol) and p-toluenesulfonic acid (1.2 mmol) in an ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][$BF_4$], 2.5 mL) proceeds very smoothly at 80 ${^{\circ}C}$ with or without an external source of fluoride, providing 73% yield in 30 min. Unlike diazonium salts, triazene precursors are stable enough to be stored for a long period of time without a noticeable decomposition.

Phase Equilibria of Ionic Liquid/Organic Compound/Supercritical CO2 Systems (이온성액체/유기화합물/초임계이산화탄소계의 상평형)

  • Lim, Bang-Hyun;Kim, Jong-Won;Paek, Sang-Min;Son, Bo-Kook;Lee, Yong-Rok;Lee, Chul Soo;Lee, Huen;Ra, Chun-Sup;Shim, Jae-Jin
    • Clean Technology
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    • v.12 no.3
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    • pp.128-137
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    • 2006
  • The volume change of an ionic liquid and the phase separation behavior of room temperature ionic liquid(RTIL)/organic compound mixture in supercritical carbon dioxide were measured in a high pressure view cell. 1-Butyl-3-methylimidazolium hexafluorophosphate ([bmim][$PF_6$]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][$BF_4$]) was used as ionic liquid(IL). and methanol and dimethyl carbonate were used as organic compound. For a fixed amount of [bmim][$PF_6$] the lower critical endpoint (LCEP) pressure, where the liquid phase is split, decreased as increasing the amount of organic compound. The LCEP pressure became higher as the water content of ionic liquid was higher. However, for water contents above a certain value, no LCEP was formed. LCEP appeared 1.0 MPa higher for a mixture with [bmim][$BF_4$] than with [bmim][$PF_6$]. There was almost no difference in the K-point pressures for different types of ionic liquid and for different amounts of organic liquid. When the concentration of ionic liquid([bmim][$PF_6$]) (IL/(IL+MeOH)) in the initial liquid mixture was larger than 5.9 mol% at the LCEP of the mixture, the volume of $L_1$ because larger than the volume of $L_2$. When it was smaller, however, the volume became smaller, too. The volume change of ionic liquid in the presence of carbon dioxide decreased as increasing the temperature, while it increased as increasing the pressure. For temperatures between 313.15 to 343.15K at 300 bar, it was about 123~125 % of the original volume.

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Influence of Ionic Liquid for Separation of D-tryptophan and N-CBZ-D-phenylalanine (D-tryptophan과 N-CBZ-D-phenylalanine의 분리에서 이온성 액체의 영향)

  • Jin, Yinzhe;Zheng, Jinzhu;Polyakova, Yulia;Koo, Yoon Mo;Row, Kyung Ho
    • Korean Chemical Engineering Research
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    • v.44 no.5
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    • pp.453-459
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    • 2006
  • D-tryptophan and N-CBZ-D-phenylalanine were separated using ionic liquid as additives for the mobile phase in high performance liquid chromatography (HPLC). The ionic liquid of 1-butyl-3- methylimidazolium tetrafluoroborate (${[BMIm]}^+{[BF_4]}^-$) was used. Mobile phases were 65%, 70%, and 80% methanol in water with addition of different concentrations (0.5, 1.0, 1.5, 2.0, 4.0, 6.0, 8.0, 10.0, 12.0, and 15.0 mmol/L) of the ionic liquid. The experiments were performed on stainless steel column, $3.9{\times}300mm$ i.d., packed with $15{\mu}m$ octadecyl-bonded silica gel at laboratory.The retention factor of D-tryptophan was not negligibly changed while that of N-CBZ-D-phenylalanine was decreased. The resolution between the two components were affected by the contents of methanol and ionic liquid in the mobile phase. With the small content of methanol and the high concentration of ionic liquid, the resolution was improved.

Current Status of Heat Capacity Measurement Techniques for Ionic Liquids by DSC (DSC를 이용한 이온성 액체 열용량 측정 기술 현황)

  • Jo, Ye Lim;Kim, Ki-Sub;Park, Byung Heung
    • Journal of Institute of Convergence Technology
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    • v.4 no.1
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    • pp.5-8
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    • 2014
  • Recently ionic liquids received much attention as novel materials capable of replacing traditional solvents. The applicability of the ionic liquids should be determined based on their physico-chemical properties. Heat capacity is one of the most important properties to be considered when a process is developed using the ionic liquids and currently DSC has been proved as an effective technique to measure the heat capacity. Micro DSCII can measure heat capacities of various liquids by both an isothermal step method and a scanning method. DSC Q100 and MDSC are able to measure heat capacities of several ionic liquids. For each ionic liquid linear regression of the heat capacity as a function of temperature has been performed to increase accuracy. To investigate the feasibility of ionic liquids as PCMs, their heat capacities have been measured by using Pysis I DSC. This paper briefly summarizes the present techniques of measuring heat capacities of ionic liquids by DSC.