• Bulletin of the Korean Chemical Society
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• 제31권6호
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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.

• 한국세라믹학회지
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• 제50권2호
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• pp.103-107
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• 2013

In this study, the ionic liquid 1-ethyl-3-methylimidazolium tetraflouroborate (EMI-BF4) was synthesized and purified using the liquid/liquid fractional distillation method to apply a supercapacitor. EMI-BF4 was extracted with dichloromethane from the liquid/liquid extraction method in acidic, neutral, and alkali conditions for removal of impurity, and then the electrical capacities of the purified ionic liquids were measured and compared. The electrical capacities of ionic liquids under acidic condition showed higher value than those of neutral or alkali conditions. As the ratio of ionic liquid to solvent became higher, the electrical capacity value was increased.

• Journal of Electrochemical Science and Technology
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• 제14권1호
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• pp.15-20
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• 2023

Ionic liquids are considered as a promising, alternative solvent for the electrochemical synthesis of metals because of their high thermal and chemical stability, relatively high ionic conductivity, and wide electrochemical window. In particular, their wide electrochemical window enables the electrodeposition of metals without any side reaction of electrolytes such as hydrogen evolution. The electrodeposition of silver is conducted in 1-n-butyl-3-methylimidazolium chloride ([C4mim]Cl) ionic liquid system with a silver source of AgCl. This study is the first attempt to electrodeposit silver nanoparticles without using co-solvents other than [C4mim]Cl. Pulse electrolysis is employed for the synthesis of silver nanoparticles by varying applied potentials from -3.0 V to -4.5 V (vs. Pt-quasi reference electrode) and pulse duration from 0.1 s to 0.7 s. Accordingly, the silver nanoparticles whose size ranges from 15 nm to ~100 nm are obtained. The successful preparation of silver nanoparticles is demonstrated regardless of the kinds of substrate including aluminum, stainless steel, and carbon paper in the pulse electrolysis. Finally, the antimicrobial property of electrodeposited silver nanoparticles is confirmed by an antimicrobial test using Staphylococcus aureus.

• 공업화학
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• 제20권3호
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• pp.313-316
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• 2009

다양한 조성의 이온성액체(Ionic liquid, ILs)를 사용하여 다공성 산화세륨 입자를 제조하였다. 이온성액체의 조성에 따라서 제조된 산화세륨 입자의 세공구조 및 결정의 모양이 달라지는 것을 관찰하였다. 이온성액체에서 음이온의 수소결합력 세기는 산화세륨의 세공을 형성하는데 결정적인 요인으로 작용하며, 양이온인 알킬 그룹의 길이에 따라 산화세륨 입자의 세공 크기 및 비표면적이 변하는 것을 확인할 수 있었다. 여러 가지 이온성액체 중에서 1-Buthyl-3-methylimidazolium hexafluorophosphate가 다공성 산화세륨 입자를 제조하는데 가장 효과적이었다.

• Bulletin of the Korean Chemical Society
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• 제26권11호
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• pp.1771-1775
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• 2005

An efficient and environment friendly method has been described for the synthesis of various 2-alkyl-4-hydroxy-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxides starting from N-alkylation of sodium obenzosulfimide in an ionic liquid for the first time. Ring cleavage and ring closure of the resulting product were achieved in a single step in a cost effective solvent (methanol) followed by N-alkylation of resulting alkyl 4-hydroxy-2H-1,2-benzothiazine-3-carboxylate in ionic liquid while boron triflouride was used as a catalyst along with molecular sieves in carboxamide formation step.

• Bulletin of the Korean Chemical Society
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• 제30권12호
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• pp.2883-2886
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• 2009

A simple, highly efficient and environmentally benign method for the synthesis of 3-styrylchromones from 3-formylchromones and 4-nitrophenylacetic acid/4-nitrotolune in the presence of catalytic amount of basic ionic liquid 1-butyl-3-methylimidazolium hydroxide [(bmim)OH] carried out under the influence of microwave irradiation. This method gives remarkable advantages such as, short reaction times, simple work-up procedure and moderate to good yields. The ionic liquid was successfully reused for four cycles without significant loss of activity.

• Bulletin of the Korean Chemical Society
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• 제33권4호
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• pp.1154-1158
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• 2012

A room-temperature ionic liquid (RTIL) derived from 1,4-diazabicyclo[2.2.2]octane (DABCO) consisting of tetrafluoroborate anion, 1-butyl-4-(4-sulfonylbutyl)-1,4-diazoniabicyclo[2.2.2]octane hydrogen sulfate tetrafluoroborate ($[C_4DABCOC_4SO_3H][BF_4][HSO_4]$) was synthesized and catalytically evaluated in the synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes by cyclocondensation reaction of ${\beta}$-naphthol and aryl aldehydes. This novel RTIL with an acidic $SO_3H$ group showed high catalytic activity with good to excellent yields of the desired products in short reaction times. Moreover, the catalyst could be recovered and reused at least three times with only slight reduction in its catalytic activity.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2140-2144
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• 2012

A polymer support immobilized acidic ionic liquid was prepared by copolymerization of 3-vinyl-1-(4-sulfonic acid)butylimidazolium hydrogen sulfate with styrene in the presence of benzoyl peroxide and its primary application as a solid acidic heterogeneous catalyst to the synthesis of Hantzsch 1,4-dihydropyridines through a one-pot three-component reaction of aromatic aldehydes, ethyl acetoacetate and ammonium acetate was investigated. The results showed that this heterogeneous catalyst has high catalytic activity and the desired products were obtained in good to high yields. Moreover, the catalyst was found to be reusable and a considerable catalytic activity still could be achieved after third run.

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2724-2730
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• 2012

A new heterogeneous acidic catalyst was successfully prepared by impregnation of silica (Aerosil 300) by an acidic ionic liquid, named 1-(4-sulfonic acid)butylpyridinium hydrogen sulfate [$PYC_4SO_3H$][$HSO_4$], and characterized using FT-IR spectroscopy, the $N_2$ adsorption/desorption analysis (BET), thermal analysis (TG/DTG), and X-ray diffraction (XRD) techniques. The amount of loaded acidic ionic liquid on Aerosil 300 support was determined by acid-base titration. This new solid acidic supported heterogeneous catalyst exhibits excellent activity in the synthesis of 2-aryl-2,3-dihydroquinazolin-4(1H)-ones by cyclocondensation reaction of 2-aminobenzamide with aromatic aldehydes under solvent-free conditions and the desired products were obtained in very short reaction times with high yields. This catalyst has the advantages of an easy catalyst separation from the reaction medium and lower problems of corrosion. Recycling of the catalyst and avoidance of using harmful organic solvent are other advantages of this simple procedure.

• Bulletin of the Korean Chemical Society
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• 제34권6호
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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.