• Title/Summary/Keyword: Ionic liquid.

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Recent Progress in Nanoparticle Synthesis via Liquid Medium Sputtering and its Applications

  • Cha, In Young;Yoo, Sung Jong;Jang, Jong Hyun
    • Journal of Electrochemical Science and Technology
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    • v.7 no.1
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    • pp.13-26
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    • 2016
  • Nanoparticles (NPs), which have been investigated intensively as electrocatalysts, are usually synthesized by chemical methods that allow precise size and shape control. However, it is difficult to control the components and compositions of alloy NPs. On the other hand, the conventional physical method, sputtering with solid substrates, allows for facile composition control but size control is difficult. Recently, “liquid medium sputtering” has been suggested as an alternative method that is capable of combining the advantages of the chemical and conventional physical methods. In this review, we will discuss NP synthesis via the liquid medium sputtering technique using ionic liquid and low-volatile polymer media. In addition, potential applications of the technique, including the generation of oxygen reduction reaction electrocatalysts, will be discussed.

Effect of Annealing of Nafion Recast Membranes Containing Ionic Liquids

  • Park, Jin-Soo;Shin, Mun-Sik;Sekhon, S.S.;Choi, Young-Woo;Yang, Tae-Hyun
    • Journal of the Korean Electrochemical Society
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    • v.14 no.1
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    • pp.9-15
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    • 2011
  • The composite membranes comprising of sulfonated polymers as matrix and ionic liquids as ion-conducting medium in replacement of water are studied to investigate the effect of annealing of the sulfonated polymers. The polymeric membranes are prepared on recast Nafion containing the ionic liquid, 1-ethyl-3-methylimidazolium tetrafluoroborate ($EMIBF_4$). The composite membranes are characterized by thermogravitational analyses, ion conductivity and small-angle X-ray scattering. The composite membranes annealed at $190^{\circ}C$ for 2 h after the fixed drying step showed better ionic conductivity, but no significant increase in thermal stability. The mean Bragg distance between the ionic clusters, which is reflected in the position of the ionomer peak (small-angle scattering maximum), is larger in the annealed composite membranes containing $EMIBF_4$ than the non-annealed ones. It might have been explained to be due to the different level of ion-clustering ability of the hydrophilic parts (i.e., sulfonic acid groups) in the non- and annealed polymer matrix. In addition, the ionic conductivity of the membranes shows higher for the annealed composite membranes containing $EMIBF_4$. It can be concluded that the annealing of the composite membranes containing ionic liquids due to an increase in ion-clustering ability is able to bring about the enhancement of ionic conductivity suitable for potential use in proton exchange membrane fuel cells (PEMFCs) at medium temperatures ($150-200^{\circ}C$) in the absence of external humidification.

Alternative chromatographic method for the assay test of terbutaline and salbutamol using ionic liquid assisted aqueous mobile phase

  • Mai, Xuan-Lan;Choi, Yusung;Truong, Quoc-Ky;Nguyen, Thi-Ngoc-Van;Han, Sang Beom;Kim, Kyeong Ho
    • Analytical Science and Technology
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    • v.33 no.4
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    • pp.169-176
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    • 2020
  • Separation of basic compounds using reverse phase chromatography on a silica-based stationary phase represents a major challenge, because of the interaction between the cationic sites of the basic compounds with the anionic silanols of the stationary phase. This study presents a simple, reliable, and organic solvent - free liquid chromatographic method for the determination of terbutaline and salbutamol, in which a room temperature ionic liquid (RTIL) is used as mobile phase additive. We investigated various mobile phase parameters affecting the retention of the two compounds, such as types and concentration of RTILs and, pH of the mobile phase were investigated. The developed method was validated according to International Conference on Harmonization (ICH) guidelines and successfully applied effectively to determine salbutamol sulfate in pharmaceutical preparations.

Charging of an Ionic Liquid Droplet in a Dielectric Medium (비전도성 매질 내 이온성 액체 액적의 충전 현상)

  • Im, Do Jin
    • Clean Technology
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    • v.20 no.4
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    • pp.354-358
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    • 2014
  • Ionic liquid (IL) is a salt presents in a liquid form at room temperature. Recently, it attracts huge attention due to its possibilities as a clean solvent, electrolyte, and catalyst. In the present work, the charging behavior of six different ILs were investigated using droplet contact charging phenomenon in a dielectric medium. Basically, the charging of an IL droplet can be explained by a perfect conductor theory. However, there were several different features depending on the species of ions of ILs, which requires rigorous molecular level modeling of charge transport through electrochemical reaction of IL. We hope the present results contribute to build up fundamental understanding of electrochemical charge transport of IL.

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.