• Title/Summary/Keyword: ionic liquid additives

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Influence of ionic liquid additives on the conducting and interfacial properties of organic solvent-based electrolytes against an activated carbon electrode

  • Kim, Kyungmin;Jung, Yongju;Kim, Seok
    • Carbon letters
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    • v.15 no.3
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    • pp.187-191
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    • 2014
  • This study reports on the influence of N-butyl-N-methylpyrrolidinium tetrafluoroborate ($PYR_{14}BF_4$) ionic liquid additive on the conducting and interfacial properties of organic solvent based electrolytes against a carbon electrode. We used the mixture of ethylene carbonate/dimethoxyethane (1:1) as an organic solvent electrolyte and tetraethylammonium tetrafluoroborate ($TEABF_4$) as a common salt. Using the $PYR_{14}BF$ ionic liquid as additive produced higher ionic conductivity in the electrolyte and lower interface resistance between carbon and electrolyte, resulting in improved capacitance. The chemical and electrochemical stability of the electrolyte was measured by ionic conductivity meter and linear sweep voltammetry. The electrochemical analysis between electrolyte and carbon electrode was examined by cyclic voltammetry and electrochemical impedance spectroscopy.

Lyotropic Chromonic Liquid Crystals: Effects of Additives and Optical Applications

  • Park, H.S.;Tortora, L.;Vasyuta, R.M.;Golovin, A.B.;Augustin, E.;Finotello, D.;Lavrentovich, O.D.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.307-310
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    • 2007
  • We describe effects of ionic and neutral additives on phase and structural behavior of the lyotropic chromonic liquid crystals used in preparation of optical elements such as polarizers and compensators.

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Chiral Separation of Tryptophan Enantiomers by Liquid Chromatography with BSA-Silica Stationary Phase

  • Kim Kwonil;Lee Kisay
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.1
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    • pp.17-22
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    • 2000
  • The separation of tryptophan enantiomers was carried out with medium-pressure liquid chromatography using BSA (bovine serum albumin)-bonded silica as a chiral stationary phase. The influence of various experimental factors such as pH and ionic strength of mobile phase, separation temperature, and the presence of organic additives on the resolution was studied. In order to expand this system to preparative scale, the loadability of sample and the stability of stationary phase for repeated use were also examined. The separation of tryptophan enantiomers was successful with this system. The data indicated that a higher separation factor (a) was obtained at a higher pH and lower temperature and ionic strength in mobile phase. Addition of organic additives (acetonitrile and 2-propanol) in mobile phase contributed to reduce the retention time of L-tryptophan. About $30\%$ of the separation factor was reduced after 80 days of repeated use.

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Optimization of Extraction of Astaxanthin from Portunus trituberculatus by Ionic Liquids (이온성 액체를 사용한 꽃게 껍질에서 아스타크산틴 추출 조건의 최적화)

  • Lee, Yu Jin;Lee, Yu Ri;Tang, Baokun;Row, Kyung Ho
    • KSBB Journal
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    • v.28 no.4
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    • pp.238-243
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    • 2013
  • Astaxanthin is one of the carotenoid with strong antioxidant. The conditions of extraction of astaxanthin from Portunus trituberculatus were optimized in this work. Six factors of conditions such as, extraction method, extraction solvent, ratio of solvent to raw material, temperature, and time, were investigated. For the increase of the extraction yield, ionic liquids were used as additives in the extraction solvent. The optimum extraction conditions were found: heat reflux extraction, Dichloromethane/methanol (25:75, v/v) as solvent, 1:30 of the ratio of solvent raw material, $80^{\circ}C$, 90 min, and ionic liquid as additive. As a result, 45.81 ${\mu}g/g$ of astaxanthin was extracted from waste.

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.

Effect of Concentration of Ionic Liquids on Resolution of Nucleotides in Reversed-phase Liquid Chromatography

  • Hua, Jin Chun;Polyakova, Yulia;Row, Kyung-Ho
    • Bulletin of the Korean Chemical Society
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    • v.28 no.4
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    • pp.601-606
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    • 2007
  • The chromatographic behaviors of nucleotides (inosine 5'-monophosphate, uridine 5'-monophosphate, guanosine 5'-monophosphate, and thymine monophosphate disodium salts) on a C18 column were studied with different types of ionic liquids (ILs) as additives for the mobile phase in reversed-phase liquid chromatography (RPLC). Three ILs, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]), 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIm][BF4]), and 1-ethyl-3-methylimidazolium methylsulfate ([EMIm][MS]), were used. Eluents were composed of water and methanol (90/10%, vol) with the addition of 0.5-13.0 mM of ILs. The effects of the concentration of ILs on retention and separation were investigated and discussed. The results showed that the addition of ILs affects the retention and resolution of the tested compounds. Use of 13.0 mM of [BMIm][BF4] as the eluent modifier resulted in a baseline separation of nucleotides without requiring gradient elution. This study demonstrates that ILs can be potentially applied as a mobile phase modifier in RPLC.

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.

Recent Advances in Electrodeposition Technology (전해 석출 기술의 최근 개발 동향)

  • Kim, S.K.;Reddy, R.G.
    • Journal of the Korean institute of surface engineering
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    • v.34 no.6
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    • pp.553-567
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    • 2001
  • Electrodeposition technology is widely used in industry for various kinds of coatings. Modifications in this technology led to several processes to meet various requirements. Electrolysis in ionic liquids has many advantages such as low energy consumption of energy, low pollutant emission and low operating costs. Although ionic liquids have already been used in liquid/liquid extraction processes, only recently their use in electrodeposition was exploited. Electrochemical deposition of composites is an expanding area. Coupled with the progress in the synthesis of nanometric powder, this research will open a large number of innovative materials. Pulse current plating is another electrodeposition technique which yields improved coatings. Although electrodeposition is now regarded as an environmental non-friendly process, it is economically viable and has many inherent advantages. For certain applications, alternatives to electrodeposition have not yet been fully implemented. Hence, continued research in this technology is warranted. This article reviews some recent advances in electrodeposition technology. Aspects of electrodeposition such as electrolysis in ionic liquids, electrodeposition of composites, pulse current plating techniques, metal and alloy deposition, compound deposition and effects of additives are discussed in this review.

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High Temperature Stable Eletrolyte for Dye Solar Cell (염료태양전지용 고온안정성 전해질)

  • Han, Chi-Hwan;Lee, Hak-Soo
    • 한국태양에너지학회:학술대회논문집
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    • 2009.04a
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    • pp.220-224
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    • 2009
  • The effect of addition of single and binary additives on the performance of dye-sensitized $TiO_2$ solar cells based on 1,2-dimethyl-3-propylimidazolium iodide (DMPII) in ethylene carbonate (EC) and gamma-butyrolactone (GBL) has been evaluated at different cell temperatures in the $30-120^{\circ}C$ range. The electrolyte containing a single additive, 2-(dimethylamino)-pyridine (DMAP) showed best performance, which showed further enhancement for an electrolyte containing binary additives, DMAP and 5-chloro-1-ethyl-2-methylimidazole (CEMI) in equal molar ratio. The performance of the dye sensitized solar cell (DSC) based on electrolyte containing binary additives were found to be better than an acetonitrile based electrolyte. The dependence of different photovoltaic parameters (Voc, Jsc, ff, n) of the DSC upon temperature has been studied over the $30-120^{\circ}C$ range and only a small decrease in conversion efficiency has been observed. Thus the electrolyte containing binary additives (DMAP, CEMI) in EC/GBL solvent and show better performance in the investigated temperature range ($30-120^{\circ}C$).

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A study on the Components and Detergency of Commercial Shampoos (시판 Shampoo의 성분과 세척성)

  • Choi Sang Weon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.2 no.1
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    • pp.151-155
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    • 1978
  • General components and detergency of commercial shampoos have been investigated and the results are summerized in the following. Shampoos were analyzed for surfactants and additives by KS method and surfactants were confirmed by T.L.C. Considerable differences in amounts of non volatiles and surfactants were found. Three of them contain either lanoline or sterols as additives and in the three. propylene glycol was found in their liquid part. It was shown that predominant sufactant was anionic and in all, except one. a little ampholytic surfactant was detected. But, contrary to forecast, in only one a little of non ionic surfactant was detected. Detergency of shampoos was examined using artificially soiled wool muslin. Considerable difference was found, and all shampoos showed higher detergency than a synthetic powder type detergent for textiles. There were no significant correlation between detergency and amount of surfactants or suspending power of detergents.

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