• Title, Summary, Keyword: ionic liquids

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Application of Ionic Liquids as Mobile Phase Modifier in HPLC

  • Polyakova Yulia;Koo Yoon-Mo;Row Kyung-Ho
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.1
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    • pp.1-6
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    • 2006
  • Ionic liquids are receiving an upsurge of interest as 'green' solvents; primarily as replacements for conventional media in chemical processes. Although ionic liquids are rather 'young' modifier, their great potential in high-performance liquids chromatography (HPLC) has already been demonstrated. This review presents an overview of the applications of ionic liquids as mobile phase modifiers in HPLC.

Extraction of Biomolcules by Ionic Liquids (이온성 액체를 이용한 생물분자의 추출)

  • Lee, Woo Yun;Lee, Yong Hwa;Lee, Jun;Hong, Yeon Ki
    • Journal of Institute of Convergence Technology
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    • v.4 no.2
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    • pp.23-26
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    • 2014
  • As an effective separation method for biomolecules, aqueous two-phase systems based on ionic liquids were suggested. Hydrophobic ionic liquids are more expensive and viscous in spite of their usage in the ionic liquid/water biphasic extraction compared with hydrophilic ionic liquids. In case of aqueous two-phase systems using hydrophilic ionic liquids, they can be diluted in aqueous phase. Experimental results show that aqueous two phase systems can be formed by adding appropriate amount of ionic liquids to aqueous salts solutions. The viscosity of ionic liquid aqueous phase is proportional to the cation chain length in ionic liquids. It is founded that the ionic liquid based aqueous two phase systems are effective for the separation of biomolecules such as acrylic acid.

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.

Application of Ionic Liquids in Biotechnology (생물공학에서 이온성 액체의 응용)

  • Lee Sang-Mok;Chang Woo-Jin;Koo Yoon-Mo
    • KSBB Journal
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    • v.20 no.3
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    • pp.183-191
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    • 2005
  • Ionic liquids, composed of organic cations and either organic or inorganic anions remain liquid over a wide range of temperature. ionic liquids are a new group of solvents or extractants of great interest as a potential 'green solvent'. Ionic liquids are gaining wide recognition as novel solvents in many research fields, such as chemistry, chemical engineering, electrochemitry, etc. However, not much researches have been done related to biotechnology using ionic liquids, while a lot of researches have been performed in chemistry. The merits of ionic liquids in bioseparation technology are originated from some unique properties of ionic liquids, such as negligible vapor pressure, good thermal stability, controllable viscosity and miscibility with water and organic solvents. An appropriate selection of ionic liquid for bioprocesses requires basic knowledge on physicochemical properties of ionic liquids. This review gives a brief overview on the application of ionic liquids in biotechnology, including bioconversion and bioseparation.

Effect of microwave irradiation on lipase-catalyzed reactions in ionic liquids

  • An, Gwangmin;Kim, Young Min;Koo, Yoon-Mo;Ha, Sung Ho
    • Analytical Science and Technology
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    • v.30 no.3
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    • pp.138-145
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    • 2017
  • Microwave-assisted organic synthesis has gained a remarkable interest over the past years because of its advantages - (i) rapid energy transfer and superheating, (ii) higher yield and rapid reaction, (iii) cleaner reactions. Ionic liquids are well known for their unique properties such as negligible vapor pressure and high thermal stability. With these properties, ionic liquids have gained increasing attention as green, multi-use reaction media. Recently, ionic liquids have been applied as reaction media for biocatalysis. Lipase-catalyzed reactions in ionic liquids provide high activity and yield compared to conventional organic solvents or solvent free system. Since polar molecules are generally good absorbent to microwave radiation, ionic liquids were investigated as reaction media to improve activity and productivity. In this study, therefore, the effect of microwave irradiation in ionic liquids was investigated on lipase catalyzed reactions such as benzyl acetate synthesis and caffeic acid phenethyl ester synthesis. Comparing to conventional heating, microwave heating showed almost the same final conversion but increased initial reaction rate (3.03 mM/min) compared to 2.11 mM/min in conventional heating at $50^{\circ}C$.

Synthesis and Antiwear Properties of Ammonium Dithiocarbamate-based Ionic Liquid (I) (암모니움 디티오카바메이트계 이온성 액체의 합성 및 내마모성능 (I))

  • Baek, Seung-Yeob;Kim, Nam-Kyun;Shin, Jihoon;Chung, Keunwo;Kim, Young-Wun
    • Tribology and Lubricants
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    • v.30 no.6
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    • pp.323-329
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    • 2014
  • The friction-reducing properties of lubricants containing ionic liquids based on ammonium dithiocarbamate are studied. The ionic liquids are produced through the following two steps: the synthesis of sodium alkyl dithiocarbamates via the substitution reaction of dialkylamine and carbon disulfide and their subsequent conversion into ammonium dithiocarbamate-based ionic liquids through an ion-exchange reaction with a quaternary alkyl ammonium halide salt. The structures of the ionic liquids are characterized by NMR spectroscopy and Fourier transform infrared spectroscopy. The isolated yields of the ionic liquids, which are viscous and pale yellow, are approximately 92%. The Brookfield viscosities and pour points of the ionic liquids are determined. Further, their wear resistances are measured through the four-ball wear test and the Schwingung Reibung Ver-schleiss (oscillation, friction, wear) test. The wear scar diameter of the lubricants containing 1 wt of the quaternary alkyl ammonium dithiocarbamate-based ionic liquids (0.475-0.631 mm) is significantly lower than that of the base oil (0.825 mm), proving that the ammonium dithiocarbamate-based ionic liquids have good friction-reducing characteristics. However, these friction-reducing characteristics fade significantly after long-term storage, owing to the degradation of the ionic liquids.

CO2 Solubilities in Amide-based Brønsted Acidic Ionic Liquids

  • Palgunadi, Jelliarko;Im, Jin-Kyu;Kang, Je-Eun;Kim, Hoon-Sik;Cheong, Min-Serk
    • Bulletin of the Korean Chemical Society
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    • v.31 no.1
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    • pp.146-150
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    • 2010
  • A distinguished class of hydrophobic ionic liquids bearing a Br${\o}$nsted acidic character derived from amide-like compounds were prepared by a neutralization reaction of N,N-diethylformamide, N,N-dibutylformamide, 1-formylpiperidine, and $\varepsilon$-caprolactam with trifluoroacetic acid and physical absorptions of $CO_2$ in these ionic liquids were demonstrated and evaluated. $CO_2$ solubilities in these ionic liquids were influenced by the molecular structure of the cation and were apparently increased with the molar volume. Comparison based on a volume unit reveals that $CO_2$ solubilities in these liquids are relatively higher than those in imidazolium-based ionic liquids. Henry's coefficients calculated from low-pressure solubility tests at 313 to 333 K were used to derive the thermodynamics quantities. Enthalpy and entropy of solvation may share equal contributions in solubility.

Retention Factors and Resolutions of Amino Benzoic Acid Isomers with Some Ionic Liquids

  • Zheng, Jinzhu;Polyakova, Yulia;Row, Kyung-Ho
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.6
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    • pp.477-483
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    • 2006
  • Ionic liquids in the form of organic salts are being widely used as new solvent media. In this paper three positional isomers, o-amino benzoic acid, m-amino benzoic acid, and p-amino benzoic acids were separated with four different ionic liquids as mobile phase additives using high performance liquid chromatography (HPLC). The following ionic liquids were used: 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][$BF_{4}$]), 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIm][$BF_{4}$]), 1-ethyl-3-methylimidazolium methylsulfate ([EMIm][MS]), and 1-octyl-3-methylimidazolium methylsulfate ([OMIm][MS]). The effects of the alkyl group length on the imidazolium ring and its counterion, and the concentrations of the ionic liquids on the retention factors and resolutions of amino benzoic acid isomers were tested. The results of the separations with ionic liquids as the eluents were better than those without ionic liquids. Excellent separations of the three isomers were achieved using 2.0-8.0 mM/L [OMIm][MS] and 1.0-8.0 mM/L [EMIm][MS] as the eluent modifiers.

Pd(II) Catalyzed Copolymerization of Styrene and CO in Quaternary Ammonium Ionic Liquids

  • Tian, Jing;Guo, Jin-Tang;Zhu, Cheng-Cai;Zhang, Xin;Xu, Yong-Shen
    • Macromolecular research
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    • v.17 no.3
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    • pp.144-148
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    • 2009
  • Poly(1-oxo-2-phenyltrimethylene) was synthesized by palladium-catalyzed copolymerization of styrene and carbon monoxide in quaternary ammonium ionic liquids. The $[Pd(bipy)_2][PF_6]_2$ compound had relatively more catalytic activity than $[Pd(bipy)_2][BF_4]_2$ in ionic liquids. The catalytic activity of palladium (II) composite catalyst was superior to the catalyst formed in situ from palladium acetate, 2,2-bipyridyl, and $X^-$ ($X^-=PF_6^-$, $BF_4^-$) in ionic liquids. The effects of the volume of ionic liquids, reaction time and benzoquinone content on the copolymerization were also described.

Pore-filling membrane with ionic liquids immobilized by cross-linking for high temperature PEFCs (고온 PEFC용 수소이온 전도 향상을 위한 가교된 이온성 액체를 갖는 세공충진막)

  • Baek, Ji-Suk;Choi, Young-Woo;Lee, Mi-Soon;Yang, Tae-Hyun;Kim, Chang-Soo
    • 한국신재생에너지학회:학술대회논문집
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    • pp.80.2-80.2
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    • 2010
  • The development of high temperature-proton exchange fuel cell (HT-PEFC) is a key in solving the problem of carbon monoxide poisoning of the platinum at anode as well as water management in PEFCs operated below $90^{\circ}C$. In order to overcome these main issues, PEFCs must be operated at high temperature above $120^{\circ}C$. Ionic liquids are available for HT-PEFC due to exhibiting non-volatility and thermal stability. Ionic liquids are however leached out from polymeric matrix resulting in the increase of gas permeability. In this study, we have prepared and characterized the composite membranes with the ionic liquids consisting of 1-(4-vinylbenzyl)-3-butyl imidazolium chloride immobilized by the cross-linkers in pore-filling membrane to prevent to be leached out from the membrane. We confirmed that cross-linked ionic liquids were not leached out from the composite membranes through the various characteristic analyses. It was also verified that the prepared membranes are thermally stable from the result of TG analysis. The pore-filling membranes with the immobilized ionic liquids have a high proton conductivity over $10^{-2}$ S/cm at high temperature (> $120^{\circ}C$).

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