• Title, Summary, Keyword: ionic liquids

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Ionic Liquids: An Environmentally Friendly Media for Nucleophilic Substitution Reactions

  • Jorapur, Yogesh R.;Chi, Dae-Yoon
    • Bulletin of the Korean Chemical Society
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    • v.27 no.3
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    • pp.345-354
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    • 2006
  • Ionic liquids are alternative reaction media of increasing interest and are regarded as an eco-friendly alternatives, of potential use in place of the volatile organic solvents typically used in current chemical processing methods. They are emerging as the smart and excellent solvents, which are made of positive and negative ions that they are liquids near room temperature. The nucleophilic substitution reaction is one of the important method for inserting functional groups into a carbon skeleton. Many nucleophilic substitution reactions have been found with enhanced reactivity and selectivity in ionic liquid. In this review, some recent interesting results of nucleophilic substitution reactions such as hydroxylations, ether cleavages, carbon-X (X= carbon, oxygen, nitrogen, fluorine) bond forming reactions, and ring opening of epoxides in ionic liquids are discussed.

Novel Imidazolium Ionic Liquids Containing Quaternary Ammonium Iodide or Secondary Amine for Dye-sensitized Solar Cell

  • Seo, Dong-Wan;Lim, Young-Don;Lee, Soon-Ho;Ur, Soon-Chul;Kim, Whan-Gi
    • Bulletin of the Korean Chemical Society
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    • v.32 no.8
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    • pp.2633-2636
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    • 2011
  • A new type of ionic liquid based on N-(3-aminepropyl)imidazolium iodide, called IIQAI, which consists of imidazolium and quaternary ammonium salt, and APII-(hydroxyethyl, propyl, hexyl) were synthesized and used as ionic liquid in dye-sensitized solar cells. APII-hexyl is solid, whereas IIQAI, APII-(hydroxyethyl, propyl) are viscous liquids. The synthesized ionic liquid showed relative thermal stability compared to the commercial ionic liquid of DMII. Among them, IIQAI was more stable than the other ionic liquid because of the two salt groups. APII-hydroxyethyl, which contains two hydroxyl groups, showed low viscosity with good flow. New types of ionic liquids were examined by $^1H$-NMR spectroscopy, thermo gravimetric analysis (TGA). IIQAI enabled a solar energy conversion efficiency of 6.3%, which is slightly higher than that of the referenced (DMII, 6.2%).

Significant Improvement of Catalytic Efficiencies in Ionic Liquids

  • Song, Choong-Eui;Yoon, Mi-Young;Choi, Doo-Seong
    • Bulletin of the Korean Chemical Society
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    • v.26 no.9
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    • pp.1321-1330
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    • 2005
  • The use of ionic liquids as reaction media can confer many advantages upon catalytic reactions over reactions in organic solvents. In ionic liquids, catalysts having polar or ionic character can easily be immobilized without additional structural modification and thus the ionic solutions containing the catalyst can easily be separated from the reagents and reaction products, and then, be reused. More interestingly, switching from an organic solvent to an ionic liquid often results in a significant improvement in catalytic performance (e.g., rate acceleration, (enantio)selectivity improvement and an increase in catalyst stability). In this review, some recent interesting results which can nicely demonstrate these positive “ionic liquid effect” on catalysis are discussed.

A study on composite membranes based on hydrocarbon polymers and ionic liquids for high temperature PEFCs (고온 PEFCs를 위한 탄화수소계열 고분자와 이온성 액체를 함유하는 복합막에 관한 연구)

  • Baek, Ji-Suk;Park, Jin-Soo;Kim, Kyung-Hyun;Moon, Gi-Young;Kim, Hye-Kyung;Choi, Young-Woo;Park, Go-Gun;Yang, Tae-Hyun;Kim, Chang-Soo;Shul, Young-Gun
    • 한국신재생에너지학회:학술대회논문집
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    • pp.147-148
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    • 2009
  • The water-like ionic liquids have been widely used to enable the proton conduction in ionic liquid based membranes at high temperature and anhydrous PEFCs. In this study, we synthesized various kinds of composite membranes based on hydrocarbon polymers having good thermal and mechanical stabilities at high temperatures and ionic liquids. The composite membrane consisting of hydrocarbon polymer and ionic liquid was characterized by thermogravimetric analyzer (TGA) and impedance spectroscopy. Consequently the non-aqueous composite membranes of a variety of hydrocarbon polymer and ionic liquids have good conductivity and thermal stability at high temperature conditions.

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Improvement in Dissolution of Cellulose with Ionic liquid by the Electron Beam Treatment (이온성 액체의 셀룰로오스 용해성 개선을 위한 전자빔 처리 효과)

  • Lee, Won-Sil;Jung, Wong Gi;Sung, Yong Joo
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.45 no.2
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    • pp.56-65
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    • 2013
  • Electron beam treatment was applied for improving dissolution of cellulose with ionic liquids. Two ionic liquids, 1-allyl-3-methylimidazolium chloride ([Amim]Cl]: AC) and 1,3-dimethylimidazolium methylphosphite ([Dmim][$(MeO)(H)PO_2$]: Me) were used for this experiment. Treatment with electron beams up to dose of 400 kGy resulted in the increase of hot water extract and alkali extract of cotton pulp and the great reduction in the molecular weight of cellulose. For the dissolution of cotton pulp with two ionic liquids, the electron beam treated samples showed faster dissolution. The dissolved cellulose with Me ionic liquid were regenerated with acetonitrile and the structure of regenerated cellulose showed distinct difference depending on the electron beam treatment. Those results provide the electron beam pre-treatment could be applied as an energy efficient and environmentally benign method to increase the dissolution of cellulose with ionic liquids.

Solvent Extraction of Tb(III) from Chloride Solution using Organophosphorous Extractant, its Mixture and Ionic Liquids with Amines (염산용액에서 유기인산과 아민추출제의 혼합용매와 이온성액체에 의한 Tb(III)의 용매추출)

  • Oh, Chang Geun;Son, Seong Ho;Lee, Man Seung
    • Journal of the Korean Institute of Resources Recycling
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    • v.28 no.1
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    • pp.40-46
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    • 2019
  • The solvent extraction of Tb(III) from hydrochloric acid solution was investigated by employing single organophosphorus (D2EHPA, PC88A and Cyanex 272), its mixture with Alamine 336 and ionic liquids with Aliquat 336. The equilibrium pH after the extraction with extractant mixtures and ionic liquids was higher than that by single extractants. Among the mixtures and ionic liquids, only the ionic liquid with Cyanex 272 and Aliquat 336 showed synergism to the extraction of Tb(III). The extraction percentage of Tb(III) by the extractant mixtures was lower than that by single extractant and the extraction order was in the following order : D2EHPA + Alamine 336 > PC88A + Alamine 336 > Cyanex 272 + Alamine 336. The extraction order of Tb(III) by the ionic liquids was Cyanex 272 + Aliqaut 336 > PC88A + Aliquat 336 > D2EHPA + Aliquat 336.

Preparation and characterization of proton exchange membranes in non-aqueous conduction (무수 전도성 양성자 교환막 제조 및 특성평가)

  • Park, Jin-Soo;Sekhon, S.S.;Baek, Ji-Suk;Yang, Tae-Hyun;Kim, Chang-Soo;Yim, Sung-Dae;Park, Gu-Gon
    • 한국신재생에너지학회:학술대회논문집
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    • pp.282-285
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    • 2009
  • This study presents preparation and characterization of composite membranes based on ionic liquids. The ionic liquids act as water in sulfonated membranes. On the behalf of ionic conduction through ionic liquid inside the membranes, non-aqueous membranes showed Arrenhius dependence on temperature with no external humidification. It was implied that hopping mechanism of proton was dominant in the ionic liquid based membranes. In addition, small angle X-ray (SAXS) studies provided the information on morphology of ionic clusters formed by the interaction between sulfonic acid groups of the polymers and ionic liquids. The SAXS spectra showed matrix peaks, ionomer peaks and Prodo's law for Nafion based composite membranes and only matrix peaks for hydrocarbon based ones. However, ionic conductivity and atomic force microscopy (AFM) images showed the clear formation of ionic clusters of the hydrocarbon based composite membranes. It implies for ionic liquid based high temperature membranes that it is important to use sulfonated polymers as solid matrix of ionic liquid which can form clear ionic clusters in SAXS spectra.

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Effects of Halide Anions to Absorb SO2 in Ionic Liquids

  • Lee, Ki-Young;Kim, Chang-Soo;Kim, Hong-Gon;Cheong, Min-Serk;Mukherjee, Deb Kumar;Jung, Kwang-Deog
    • Bulletin of the Korean Chemical Society
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    • v.31 no.7
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    • pp.1937-1940
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    • 2010
  • Ionic liquids with halide anions were prepared and the dependency of halide anions on the $SO_2$ solubility of ILs was investigated. The study shows that the $SO_2$ solubility of ionic liquids lies in the range 1.91~2.22 $SO_2$/ILs mol ratio. $SO_2$ solubility in ionic liquids with varying halide anions follows the order Br > Cl > I. Theoretical investigation was also conducted at the B3LYP level using the Gaussian 03 program. From the theoretical consideration of the interaction between $SO_2$ and [EMIm]X (where X = Cl, Br, and I), it has been proposed that primary interaction of halide occurs with $C_2$-H of the imidazolium and S of $SO_2$. Experimental results further shows that the absorption and desorption process of $SO_2$ in ILs was reversible by the three cycles of the absorption at $50^{\circ}C$ and desorption at $140^{\circ}C$. The reversibility of $SO_2$ absorption was confirmed by FT-IR studies.

Applications of Ionic Liquids: The State of Arts (이온성액체의 응용기술 동향)

  • Lee, Hyunjoo;Lee, Je Seung;Kim, Hoon Sik
    • Applied Chemistry for Engineering
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    • v.21 no.2
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    • pp.129-136
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    • 2010
  • Ionic liquids are expanding their applications in various fields of chemistry, due to their unique properties such as negligible volatility, immisciblity with hydrocarbons, high electrical conductivity, and tunable acidity and basicity. In this paper, the physical properties, synthesis, and commercial applications of ionic liquids are discussed. Recent research trends are also briefly reviewed, particularly on application of ionic liquids to catalysis, biomass, and $CO_{2}$ capture and utilization.