• Title, Summary, Keyword: ionic liquids

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Influence of Ionic Liquid as a Template on Preparation of Porous η-Al2O3 to DME Synthesis from Methanol

  • Yoo, Kye-Sang;Lee, Se-Hee
    • Bulletin of the Korean Chemical Society
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    • v.31 no.6
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    • pp.1628-1632
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    • 2010
  • Porous ${\eta}-Al_2O_3$ was synthesized by modified sol-gel method using ionic liquid as a templating material. The addition of ionic liquid assisted to increase the surface area of alumina. However, the acidity of aluminas prepared with ionic liquids was hardly affected regardless the change of its structural properties. Among the ionic liquids used in this study, 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][$PF_6$]) was the most effective ionic liquid to produce porous ${\eta}-Al_2O_3$ particles. The catalytic performance of these aluminas has been investigated in dehydration of methanol to produce dimethyl ether. The alumina prepared with [Bmim][$PF_6$] outperformed the other aluminas except ${\eta}-Al_2O_3$ without modification in this reaction.

Removal of Na+ from Ionic Liquids by Zeolite for High Quality Electrolyte Manufacture

  • Cho, Won-Je;Seo, Yongseong;Jung, Soon Jae;Lee, Won Gil;Kim, Byung Chul;Mathieson, Grant;Yu, Kook-Hyun
    • Bulletin of the Korean Chemical Society
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    • v.34 no.6
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    • pp.1693-1697
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    • 2013
  • This study develops a novel method to remove the free cations created during the synthesis of ionic liquid. The cations are removed from the ionic liquid by size-selective adsorption onto chemically surface-modified Zeolite. The porous crystal nano-structure of Zeolite has several electron-rich Al sites to attract cations. While large cations of an ionic liquid cannot access the Zeolite nano-structure, small cations like $Na^+$ have ready access and are adsorbed. This study confirms that: $Na^+$ can be removed from ionic liquid effectively using Zeolite; and, in contrast to the conventional and extensively applied ion exchange resin method or solvent extraction methods, this can be done without changing the nature of the ionic liquid.

The effect of cyano groups on the solubility of carbon dioxide in ionic liquids containing cyano groups in anion

  • Cho, Hang-Kyu;Kim, Ji Eun;Lim, Jong Sung
    • The Korean Journal of Chemical Engineering
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    • v.34 no.5
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    • pp.1475-1482
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    • 2017
  • The solubility of carbon dioxide ($CO_2$) was investigated using three ionic liquids containing different numbers of cyano groups in the anion, 1-hexyl-3-methylimidazolium tricyanomethanide ($[c_6mim][C(CN)_3]$), 1-hexyl-3-methylimidazolium dicyanamide ($[c_6mim][N(CN)_2]$), and 1-hexyl-3-methylimidazolium thiocyanate ($[c_6mim][SCN]$). The $CO_2$ solubilities were determined by measuring the bubble point pressures of the $CO_2$+ionic liquid mixtures at temperatures ranging from 303.15 to 373.15 K and pressure up to 105 MPa. The experimental results showed that the solubilities of $CO_2$ in ionic liquids increased with pressure, decreased with temperature, and increased with the length of the alkyl chains in the cation. Furthermore, a higher $CO_2$ solubility was achieved in the ionic liquid with more cyano groups in the anion. The experimental data were correlated with the Peng-Robinson equation of state (PR-EoS), using the conventional van der Waals one fluid mixing rule and the modified Lydersen-Joback-Reid method. The average absolute deviation values of pressure (AAD-P) were 0.0658 for $CO_2+[c_6mim][SCN]$, 0.0633 for $CO_2+[c_6mim][N(CN)_2]$, and 0.0761 for $CO_2+[c_6mim][C(CN)_3]$ system.

Electrochemical properties of PEO-based solid polymer electrolytes blended with different room temperature ionic liquids

  • Kim, Y.H.;Cheruvally, G.;Choi, J.W.;Ahn, J.H.;Kim, K.W.;Ahn, H.J.;Song, C.E.;Choi, D.S.
    • Proceedings of the Polymer Society of Korea Conference
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    • pp.276-276
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    • 2006
  • The incorporation of room temperature ionic liquids (IL) in poly (ethyleneoxide)-lithium salt (PEO-LiX) based solid polymer electrolytes is presently being studied as an effective means of enhancing the room temperature ionic conductivity of these electrolytes to acceptable levels for use in lithium batteries. In the present study, $PEO_{20}-LiTFSI$ solid polymer electrolyte was blended with three different ionic liquids, namely 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMIMTFSI), 1-butyl-3-methylimidazolium tetraflouroborate (BMIMBF4) and 1-butyl-3-methylimidazolium trifluromethanesulfonate ($BMIMCF_{3}SO_{3}$). The incorporation of all these ILs resulted in the enhancement of ionic conductivity, the effect being more pronounced at lower temperatures. Electrochemical properties of the blended electrolytes were studied by cyclic voltammetry, linear sweep voltammetry and interfacial resistance measurements. The optimum results were obtained with the blending of BMIMTFSI in the solid polymer electrolyte.

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Application of Silica-supported Ionic Liquid Catalysts to Cycloaddition of CO2 (CO2 부가반응에 적용된 Silica 담지 이온성 액체 촉매)

  • Kim, Dong-Woo;Kim, Hyeon-Gook;Cho, Deug-Hee
    • Applied Chemistry for Engineering
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    • v.27 no.3
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    • pp.239-244
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    • 2016
  • The catalytic applicability of various ionic liquids immobilized on different silica-supports such as amorphous, SBA, MCM and commercial silica for the cycloaddition of $CO_2$ and epoxides is reviewed in this work. The effects of different structures of supported ionic liquids and silica supports in the synthesis cyclic carbonate by the cycloaddition of $CO_2$ have been remarked. The studies revealed that ionic liquids possessing functional groups or metals exhibited increased catalytic performance towards cyclic carbonate synthesis. Moreover, the reusability of SSIL catalyst and mechanism for the cycloaddition of $CO_2$ were studied.

Phase-and Size-Controlled Synthesis of CdSe/ZnS Nanoparticles Using Ionic Liquid (이온성 액체에 의한 CdSe/ZnS 나노입자의 상과 크기제어 합성)

  • Song, Yun-Mi;Jang, Dong-Myung;Park, Kee-Young;Park, Jeung-Hee;Cha, Eun-Hee
    • Journal of the Korean Electrochemical Society
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    • v.14 no.1
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    • pp.1-8
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    • 2011
  • Ionic liquids are room-temperature molten salts, composed of organic mostly of organic ions that may undergo almost unlimited structural variation. We approach the new aspects of ionic liquids in applications where the semiconductor nanoparticles used as sensitizers of solar cells. We studied the effects of ionic liquids as capping ligand and/or solvent, on the morphology and phase of the CdSe/ZnS nanoparticles. Colloidal CdSe/ZnS nanoparticles were synthesized using a series of imidazolium ionic liquids; 1-R-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([RMIM][TFSI]), where R = ethyl ([EMIM]), butyl ([BMIM]), hexyl ([HMIM]), octyl ([OMIM]). The average size of nanoparticles was 8~9 nm, and both zinc-blende and wurtzite phase was produced. We also synthesized the nanoparticles using a mixture of trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide ([$P_{6,6,6,14}$][TFSI]) and octadecene (ODE). The CdSe/ZnS nanoparticles have a smaller size (5.5 nm) than that synthesized using imidazolium, and with a controlled phase from zinc-blende to wurtzite by increasing the volume ratio of [$P_{6,6,6,14}$][TFSI]. For the first time, the phase and size control of the CdSe/ZnS nanoparticles was successfully demonstrated using those ionic liquids.

Extraction Equilibria of Succinic Acid by Using Aqueous Two Phases System Containing Imidazolium Ionic Liquids and Salts (이미다졸계 이온성액체와 염을 포함한 수상이성분계를 이용한 숙신산의 추출 평형)

  • Lee, Yong Hwa;Kang, Jeong Won;Hong, Yeon Ki;Kim, Ki-Sub
    • Clean Technology
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    • v.20 no.4
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    • pp.349-353
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    • 2014
  • Succinic acid is an important precursor in industries producing biopolymers, pharmaceutical and food additives and green solvents. However, due to the high price of petroleum and the global $CO_2$ emission, the biological production of succinic acid from renewable biomass is a novel process due to the fixation of $CO_2$ into succinate during fermentation. In this study, aqueous two phase systems based on imidazolium ionic liquids/$K_2HPO_4$ were used as an effective separation and concentration process for succinic acid. Experimental results show that aqueous two phase systems can be formed by adding appropriate amount of imidazolium ionic liquids to aqueous $K_2HPO_4$ solutions in the presence of succinic acid. It can be found that the ability of imidazolium ionic liquids for phase separation followed the order [HMIm][Br]${\fallingdotseq}$[OMIm][Br]>[BMIm][Br]>[EMIm][Br]. The maximum value of extraction efficiency for succinic acid was about 90% and the amount of coextracted water into top phase is proportional to the chain length of cation in imidazolium ionic liquids. It was concluded that the aqueous two phase systems composed of imidazolium ionic liquids/$K_2HPO_4$ was effective for the selective extraction and concentration of succinic acid.

Precious Metals Extraction Processing in Chloride Media by Using Ionic Liquids as Novel Extractant Systems

  • Kumar, Jyothi Rajesh;Choi, In-Hyeok;Lee, Jin-Young
    • Korean Chemical Engineering Research
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    • v.55 no.4
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    • pp.503-509
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    • 2017
  • The present experimental study proposed two ionic liquids (ILs) namely [Aliquat 336] [$HSO_4$] (prepared and characterized at our laboratory) and Cyphos 101 IL (supplied by Cytec Company) dissolved in two different diluents such as DCM (di-chloro-methane) and toluene applied for PMs extraction. The first IL [Aliquat 336] [$HSO_4$] prepared and confirmed the formation of final product by using FT-IR and TGA studies. The primary experiment in solvent extraction processing is kinetic effect; 0 to 30 time varied for PMs by using two ILs and confirmed the optimized extraction equilibrium time. This study was conducted for PMs (Pt, Rh and Cu) extraction and separation from each other by using proposed ILs. This is the primary study of the utilizing green solvents such as ILs as an extractant system for Pt, Rh and Cu extraction and possible separation.

Brønsted Acidic Ionic Liquids as Efficient Catalysts for Clean Synthesis of Carbamatoalkyl Naphthols

  • Tavakoli-Hoseini, Niloofar;Heravi, Majid M.;Bamoharram, Fatemeh F.;Davoodnia, Abolghasem
    • Bulletin of the Korean Chemical Society
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    • v.32 no.3
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    • pp.787-792
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    • 2011
  • Under mild conditions and without any additional organic solvent, synthesis of carbamatoalkyl naphthols could be carried out in the present of two halogen-free Br${\phi}$nsted acidic ionic liquids, 3-methyl-1-(4-sulfonic acid)butylimidazolium hydrogen sulfate and N-(4-sulfonic acid)butylpyridinium hydrogen sulfate. A wide range of aromatic aldehydes easily undergo condensation with $\beta$-naphthol and methyl or benzyl carbamate to afford the desired products of good purity in excellent yields. The present methodology offers several advantages such as a simple procedure with an easy work-up, short reaction times, and excellent yields. The catalysts could be recycled and reused for several times without substantial reduction in their catalytic activities.