• Bulletin of the Korean Chemical Society
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• v.29 no.12
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• pp.2505-2508
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• 2008

• Journal of the Korean Electrochemical Society
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• v.14 no.4
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• pp.201-207
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• 2011

Supercapacitor has been studied actively as one of the most promising electrochemical energy storage system for a wide range of applications. To increase the energy density of supercapacitor, the introduction of ionic liquids is required. In this study, two types of EMI-$BF_4$ based on quaternary imidazolium salt were prepared with quaternary reaction and anion exchange. The structural characterization and thermal stability were analyzed by nuclear magnetic resonance($^1H$-NMR) and thermogravimetric analysis(TGA), respectively. Thermal stability of the EMI-$BF_4$ using TGA confirmed that, after heat treatment, the decomposition temperature of EMI-$BF_4$ was increased. Supercapacitors were fabricated with synthesized and commercial ionic liquids, and charge/discharge characteristics were also investigated. The capacity of supercapacitor, for synthesized and commercial EMI-$BF_4$ were determined to be 0.067 F and 0.073 F respectively, by means of charge/discharge test.

• Journal of the Korean Electrochemical Society
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• v.13 no.3
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• pp.181-185
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• 2010

Polyaniline-ionic liquid composite was prepared and investigated its physical and electrochemical properties. The quasi-solidification was presented in imidazolium-based ionic liquid (1-methly-3-propylimidazolium iodide, PMI-I) containing above 30 wt% of polyaniline (emeraldine base), which exhibited around 80% decrease of conductivity compared to pristine ionic liquid, resulting in fibril structure trough ${\pi}-{\pi}$ self-assembled of imidazolium aromatic ring of ionic liquid on polyaniline framework.

• Bulletin of the Korean Chemical Society
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• v.29 no.9
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• pp.1705-1710
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• 2008

Imidazolium based zwitterions, 1,2-dimethylimidazolium-3-n-propanesulfonate (DMIm-3S) and 1-Butylimidazolium-3-n-butanesulphonate (BIm-4S), were synthesized, and utilized them as additive for Li ion cell comprising of graphite anode and $LiCoO_2$ cathode. The use of 10 wt% of DMIm-3S in 1 M $LiPF_6$, EC-EMCDMC (1:1:1 (v/v)) resulted in the increased high rate charge-discharge performance. The low temperature performance of the Li ion cells at about −20 ${^{\circ}C}$ was also enhanced by these zwitterion additives. The DMIm- 3S additive resulted in the better capacity retention by the Li-ion cells even after 120 cycles with 100% depth of discharge (DOD) at 1 C rate in room temperature. Surface morphology of both graphite and $LiCoO_2$ electrode before and after 300 cycles was studied by scanning electron microscopy. An analogous study was performed using liquid electrolyte without any additive.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2325-2332
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• 2012

A series $[C_3Omim]$[X] of imidazolium cation-based ILs, with ether functional group on the alkyl side-chain have been synthesized and structure of the materials were confirmed by various techniques like $^1H$, $^{13}C$ NMR spectroscopy, MS-ESI, FTIR spectroscopy and EA. More specifically, the influence of changing the anion with same cation is carried out. The absorption capacity of $CO_2$ for ILs were evaluated at 30 and $50^{\circ}C$ at ambient pressure (0-1.6 bar). Ether functionalized ILs shows significantly high absorption capacity for $CO_2$. In general, the $CO_2$ absorption capacity of ILs increased with a rise in pressure and decreased when temperature was raised. The obtained results showed that absorption capacity reached about 0.9 mol $CO_2$ per mol of IL at $30^{\circ}C$. The most probable mechanism of interaction of $CO_2$ with ILs were investigated using FTIR spectroscopy, $^{13}C$ NMR spectroscopy and result shows that the absorption of $CO_2$ in ether functionalized ILs is a chemical process. The $CO_2$ absorption results and detailed study indicates the predominance of 1:1 mechanism, where the $CO_2$ reacts with one IL to form a carbamic acid. The $CO_2$ absorption capacity of ILs for different anions follows the trend: $BF_4$ < DCA < $PF_6$ < TfO < $Tf_2N$. Moreover, the as-synthesized ILs is selective, thermally stable, long life operational and can be recycled at a temperature of $70^{\circ}C$ or under vacuum and can be used repeatedly.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.829-833
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• 2007

IPMC-EMIM (Ionic Polyer Metal Composites + 1-ethyl-3- methyl imidazolium trifluromethane sulfonate, EMIM-Tfo) is fabricated by substituting ionic liquid for water in Nafion film, which improves water sensitiveness of IPMC and guarantees uniform performance regardless of the surrounding environment. In this paper, we will introduce the design and analysis of AF Lens Actuator using IPMC-EMIM. We will briefly introduce the procedure of fabrication of IPMC-EMIM first, and proceed on to define the necessary variables, analyze performance by changing the value of the variables, make a designed AF Lens Actuator, and measure the performance of one of them.

• Carbon letters
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• v.11 no.3
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• pp.216-223
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• 2010

Two-types of ionically modified multi-walled carbon nanotube (MWNTs) based sensors were developed by radiationinduced graft polymerization using vinyl monomers such as 3-(butyl imidazol)-2-(hydroxyl)propyl methyl methacrylate and 1-[(4-ethenylphenyl)methyl]-3-buthyl-imidazolium chloride with ionic properties, in aqueous solution at room temperature. Subsequently, the tyrosinase-immobilized biosensor was fabricated by a hand-casting of the ionic property-modified MWNTs, tyrosinase, and chitosan solution as a binder onto ITO glass surface. The sensing ranges of the tyrosinase-biosensor for phenol in phosphate buffer solution was in the range of 0.005~0.2 mM. The total phenolic compounds mainly such as caffeine of the tyrosinase-immobilized biosensor for commercial coffee were also determined.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2010.04a
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• pp.199-199
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• 2010

Polymeric membranes have been widely used to separate gas mixtures, such as $O_2/N_2,\;CO_2/CH_4,\;CO_2/N_2$, and olefin/paraffin. The permeation selectivity is the ratio between composition ratio at the permeate side and composition ratio at the feed side. In addition, the permeation selectivity is a product of solubility selectivity and diffusivity selectivity. We present a novel idea and describe its experimental result, which was achieved by preparing polymer gel films that included a room temperature ionic liquid (RTIL) in a polymer matrix. It is known that $CO_2$ can dissolve easily in imidazolium-based RTILs. We prepared polymer-ionic liquid gel films using an ionic liquid, 1-ethyl-3-methylimidazolium acetate ([emim] acetate, C-tri) and a host polymer, poly (vinyl acetate) (PVAc, Aldrich).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.254-254
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• 2010

We report aqueous synthesis of cadmium telluride (CdTe) quantum dots(QDs) using imidazolium-based ionic liquids with various functional groups. The functinalized ionic liquids were designed to have thiol groups, and then phase transfer with aqueous or organic solvents can be adjusted by changing side chain lengths of the cation and the choice of anion. The quantum yield was obtained IL-functionalized CdTe QDs reached up to 40% by post-treatment method.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2212-2216
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• 2011

An ionic liquid-based ultrasonic-assisted extraction method has been successfully applied to the effective extraction of phenolic compounds from Laminaria japonica Aresch. Three kinds of 1-alkyl-3-methyl-imidazolium with different cations and anions were evaluated for extraction efficiency. The results showed that both the characteristics of anions and cations have remarkable effects on the extraction efficiency. In addition, the ionic liquid-based ultrasonic-assisted extraction procedure was also optimized on some extraction parameters, such as ultrasonic power, extraction time and solid-liquid ratio. Compared with the conventional solvent, the optimum approach gained the highest extraction efficiency within the shortest extraction time. Average recoveries of phenolic compounds were from 75.5% to 88.3% at three concentration levels.