• Bulletin of the Korean Chemical Society
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• 제30권1호
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• pp.53-56
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• 2009

At room-temperature, a facile, seedless, and environmentally benign green route for the synthesis of star like PbS nanoclusters at 7 min in aqueous solution of 1-ethyl-3-methylimidazolium ethyl sulfate, [EMIM] [$EtSO_{4}$], room-temperature ionic liquid (RTIL), via ultrasonic irradiation is proposed. The X-ray diffraction studies display that the products are excellently crystallized in the form of cubic structure. An energy dispersive X-ray spectroscopy (EDX) investigation reveals the products are extremely pure. The absorption spectra of the product exhibit band gap energy of about 4.27 eV which shows an enormous blue shift of 3.86 eV that can be attributed to very small size of PbS nanoparticles produced and quantum confinement effect. A possible formation mechanism of the PbS nanoparticles using ultrasonic irradiation in aqueous solution of the RTIL is presented.

• Bulletin of the Korean Chemical Society
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• 제32권spc8호
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• pp.3149-3151
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• 2011

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3458-3460
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• 2012

• Bulletin of the Korean Chemical Society
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• 제27권11호
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• pp.1851-1853
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• 2006

We herein report a new analytical application of XPS to the identification of organic molecules in room temperature ionic liquid for the first time. An organic compound, propargylamine (1), produced in 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][$PF_6$]), which is one of the room temperature ionic liquids (RTILs), via $A^3$ coupling reaction, is characterized by means of x-ray photoelectron spectroscopy (XPS) rather than using conventional organic compound analysis techniques. There are four non-equivalent carbons in RTILs and 1 each. The ratios of normalized integrated areas of the deconvoluted binding energy of core electron of carbon (C1s) peaks are well matched to the number of carbons in those compounds. The binding energies of C1s of the featured carbons in 1, C4 (sp carbons in acetylene group) and C5 ($sp^2$ carbons in benzene ring), are assigned 286.2 and 285.4 eV, respectively. These results will be able to provide an important tool and a new strategy for the analysis of organic molecules

• Journal of Industrial and Engineering Chemistry
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• 제68권
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• pp.168-172
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• 2018

This study first investigates the effect of the choice of cation on three different ionic-liquid-based gel polymer electrolytes (ILPEs) with polyimide membranes. The preparation of three ILPEs based on electrospun membranes of PI and incorporating a room-temperature ionic liquid, 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide complexed with lithium bis(trifluoromethylsulfonyl)imide, is described. ILPE-EMImTFSI has an ionic conductivity as high as $5.3{\times}10^{-3}S\;cm^{-1}$ at $30^{\circ}C$. Furthermore, it shows higher thermal stability and electrochemical oxidation stability compared to the other two ILPEs because of its stronger bonds. These results indicate that polyimide-based ILPE-EMImTFSI is a good candidate for use in high-safety rechargeable lithium metal batteries.

• 공업화학
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• 제23권1호
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• pp.14-17
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• 2012

다양한 종류의 상온 이온성액체를 이용한 화학적 환원법으로 미세 은 입자를 제조하였다. 이온성액체의 음이온의 종류에 따라 제조된 은 입자는 다양한 크기와 입도분포를 가지는 것이 관찰되었으며, 이는 이온성액체의 음이온이 은 입자들의 결합에 영항을 주기 때문이다. 여러 가지 이온성액체 중에서 미세 은입자를 제조하는데 있어서 가장 효과적인 이온성액체는 1-Butyl-3-methylimidazolium hexafluorophosphate였다.

• 한국재료학회지
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• 제29권2호
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• pp.121-128
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• 2019

Supercapacitors are attracting much attention in sensor, military and space applications due to their excellent thermal stability and non-explosion. The ionic liquid is more thermally stable than other electrolytes and can be used as a high temperature electrolyte, but it is not easy to realize a high temperature energy device because the separator shrinks at high temperature. Here, we report a study on electrochemical supercapacitors using a composite electrolyte film that does not require a separator. The composite electrolyte is composed of thermoplastic polyurethane, ionic liquid and fumed silica nanoparticles, and it acts as a separator as well as an electrolyte. The silica nanoparticles at the optimum mass concentration of 4wt% increase the ionic conductivity of the composite electrolyte and shows a low interfacial resistance. The 5 wt% polyurethane in the composite electrolyte exhibits excellent electrochemical properties. At $175^{\circ}C$, the capacitance of the supercapacitor using our free standing composite electrolyte is 220 F/g, which is 25 times higher than that at room temperature. This study has many potential applications in the electrolyte of next generation energy storage devices.

• 멤브레인
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• 제16권4호
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• pp.268-275
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• 2006

이온전도도가 높은 상온 이온액을 이용하여 저온, 고온 상분리에 의한 multi-stage phase separation process로 새로운 고정화 이온액 전해질 막(supported ionic liquid electrolyte membranes, SILEMs)을 제조하였다. PVDF와 imidazolium계 이온액을 각각 분리막 소재와 전해액으로 사용하였다. 이온전도도 특성을 알아보기 위해 SILEMs을 LCR meter를 이용 해 $30^{\circ}C$부터 $130^{\circ}C$까지 실험하였다. 가습조건에서 cast Nafion 막의 이온전도도는 $30^{\circ}C$부터 $100^{\circ}C$까지는 직선적으로 증가하였으나 그 이후에는 감소하였다. 그러나 SILEMs의 경우 운전온도의 증가에 따라 이온전도도가 증가하였다. 또한 SILEMs의 이온전도도 거동은 가습과 관계없이 거의 같았다. SILEMs의 이온전도도는 $30^{\circ}C$에서 $2.7{\times}10^{-3}S/cm$이었고 온도가 $130^{\circ}C$까지 증가함에 따라 $2.2{\times}10^{-2}S/cm$까지 거의 직선적으로 증가하였다. $SiO_2$를 이용하여 SILEMs의 물리적 성질에 대한 무기첨가제의 영향에 관하여 연구하였다. SILEMs에 $SiO_2$의 첨가는 비록 약간의 이온전도도 감소는 있으나 SILEMs의 기계적 강도를 향상시킬 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제30권1호
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• pp.233-235
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• 2009

• 전기화학회지
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• 제14권3호
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• pp.152-156
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• 2011

A room temperature ionic liquid (RTIL) based on trihexyl (tetradecyl)phosphonium bis(trifluoromethanesulfonyl) imide ([$(C_6H_{13})_3P(C_{14}H_{29)}$] [TFSI];P66614TFSI) was synthesized and analyzed to determine their characteristics and properties. The bis(trifluoromethanesulfonyl)imide (TFSI) anion is widely studied as an ionic liquid (IL) forming anion which imparts many useful properties, notably electrochemical stability. Especially its electrochemical and physical characteristics for solvent of lithium ion battery were investigated in detail. $P_{66614}$ TFSI exhibits fairly low conductivity (0.89 mS $cm^{-1}$) and higher viscosity (298 K: 277 cP; 343 K: 39 cP) than other ionic liquids, but it exhibits a high thermal stability (over $400^{\circ}C$). Especially corrosion behavior on Al current collector was tested at room temperature and further it was confirmed that thermal resistivity for Al corrosion was highly increased in 1.0M LiTFSI/$P_{66614}$-TFSI electrolyte comparing with other RTILs by linear sweep thermometry.