• Transactions of the Korean hydrogen and new energy society
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• v.20 no.3
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• pp.238-244
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• 2009

We investigated the electrochemical properties of lithium/molybdenum sulfide(Li/MoS$_2$) using tetra (ethylene glycol) dimethyl ether(TEGDME) electrolyte. The Li/TEGDME/MoS$_2$ cell showed the first discharge capacity of 288mAhg$^{-1}$. From the XRD, SEM results of the MOS$_2$ electrode in various cut-off voltage during charge-discharge process, MoS$_2$ partly changed into Li$_2$S and Mo during discharge and Li$_2$S partly recovered into MOS$_2$ and Li during charge. Full charged MOS$_2$ electrode showed lump shape of big size, which might be related to agglomerate of MoS$_2$ particles. Therefore, the degradation might be related to decrease of active material for electrochemical reaction by agglomeration of MOS$_2$.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.24-27
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• 2009

Solid-state dye-sensitized solar cells (DSSCs) have been constructed employing supramolecular electrolytes with multiple hydrogen bonding. A supramolecule was facilely synthesized by one-pot reaction between the amines of methyl isocytosine (MIC) and the epoxy groups of poly(ethylene glycol diglycidyl ether) (PEGDGE) to produce quadruple hydrogen bonding units. Hydrogen bonding interactions and dissolution behavior of salt in supramolecular electrolytes are investigated. The ionic conductivity of the supramolecular electrolytes with ionic liquid, i.e. 1-methyl-3-propylimidazolium iodide (MPII) reaches $8.5{\times}10^{-5}$ S/cm at room temperature, which is higher than that with metal salt (KI). A worm-like morphology is observed in the FE-SEM micrographs of $TiO_2$ nanoporous layer, due to the connection of $TiO_2$ nanoparticles resulting from adequate coating by electrolytes. DSSCs employing the supramolecular electrolytes with MPII and KI exhibit an energy conversion efficiency of 2.5 % and 0.5 %, respectively, at 100 $mW/cm^2$, indicating the importance of the cation of salt. Solar cell performances were further improved up to 3.7 % upon introduction of poly(ethylene glycol dimethyl ether) (PEGDME) with 500 g/mol.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6590-6596
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• 2013

Carbon dioxide should be removed to increase the productivity of dimethyl ether(DME) from the DME manufacturing process. In this study, carbon dioxide can be removed using a physical absorbent through a solvent absorption method and membrane separation method. After performing the simulation for the carbon dioxide removal process, the energy consumption of the processes was compared. Methanol was used as a physical absorbent for the rectisol process, dimethyl ethers of polyethylene glycol for the Selexol process and N-methyl pyrrolidone for the Purisol process. By performing the simulation for each process, the energy consumption was compared. The Purisol process had the lowest energy consumption, followed in order by the Selexol process, Rectisol process and Membrane process. Therefore, the Purisol process was the most suitable method for the carbon dioxide process in the DME manufacturing process.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1235-1242
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• 2019

In this study, prepolymer was synthesized through the reaction of isoporon diisocyanate (IPDI) and dimethylolbutanoic acid (DMBA) based on poly (tetramethylene ether) glycol (PTMG) for the synthesis of water-soluble polyurethane to be used as a leather surface coating applied with ethyl acetate and piperazine. Thereafter, the piperazine was chain-extended with 0.01 M, 0.03 M, 0.05 M, and 0.07 M in the water-dispersed resin, and the tensile strength, elongation, CV (cyclic voltammetry), and solvent resistance analysis were performed. Tensile strength of the prepared sample was measured at 5.422 kg_f/㎟ when the piperazine content was 0.07M, and elongation was measured as 587% when the piperazine was 0.01M. Solvent resistance analysis showed the same solvent resistance regardless of piperazine content, and the redox potential was changed according to piperazine content through CV measurement.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.443-450
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• 1994

Polyelectrolytes of various ionization degrees, which are prepared by neutralization of poly(acrylic acid)(PAA), were crosslinked by ethylane glycol diglycidyl ether(EGDE) in aqueous solution. $C_{gel}$, the minimum polymer concentration at which gelation occurs, was higher than expected. $C_{gel}$ was comparable with that of neutral polymer. This is considered to be due to the size contraction of polyelectrolyte, which comes from ionic strength increase as polymer concentration is increased. $C_{gel}$ is low when molecular weight of the sample becomes high. It reveals that polyelectrolyte is crosslinked in coil form not in extended rod form. This behavior is similar to the crosslinking of neutral polymers. Polyelectrolytes of partially ionized sample generally follow the behavior of fully ionized polyelectrolyte. Polyelectrolyte with added salt was also studied. Considering the pH dependence of EDGE reactivity it was difficult to compare the system which differs in pH significantly.

• Journal of Korea Soil Environment Society
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• v.1 no.1
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• pp.81-88
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• 1996

To study the Cd adsorption in the presence of competing ions in soil-solution interphase, three soil samples from the Bt horizon were taken and analyzed for their physical and chemical properties. Adsorption of ethylene glycol monoethyl ether(EGME) and N, were determined to establish the specific surface area of the soils. We attempted to establish a qeneralizing competitive sorption isotherms for soils of entirely different composition of the solid phase, resulting in the routine use as a guidelines for the fate of reactive solute in soil profiles. Many physicochemical factors including competitive adsorption bettween solutes will affect the general adsorption phenomena as shown in a single not only on the soil:solution ratio used, but also on the surface areas of its respective soil samples. This phenomenon was attributed to competition Cd for sorption sites with Mg by different soil constituents. These adsorption isotherms are able to use as examples to demonstrate that this phenomenon can complicate the development of a standardized batch adsorption procedure as well as interpreting fate and adsorption of toxic inorganic compounds.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.4 s.37
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• pp.359-363
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• 2005

The organic insulation devices with MIM (metal-insulator-metal) structures as PVP gate insulation films were prepared for the application of organic thin film transistors (OTFT). The co-polymer organic insulation films were synthesized by using PVP(poly-4-vinylphenol) as solute and PGMEA (propylene glycol monomethyl ether acetate) as solvent. The cross-linked PVP insulation films were also prepared by addition of poly (melamine-co-formaldehyde) as thermal hardener. The leakage current of the cross-linked PVP films was found to be about 300 pA with low current noise. and showed better property in electrical properties as compared with the co-polymer PVP insulation films. In addition, cross-linked PVP insulation films showed better surface morphology (roughness), showing about 0.11${\~}$0.18 nF in capacitance for all PVP film samples.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.3
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• pp.498-506
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• 2002

Improvements of fuel properties have become essential for exhaust emission reduction as well as for optimization of directly-related design factors and exhaust gas aftertreatment. In this study, the potential possibility of oxygenated fuel such as ethylene glycol mono-n-butyl ether(EGBE) was investigated for the sake of smoke reduction from diesel engine. Because EGBE include oxygen content approximately 27%, it is a kind of effective oxygenated fuel that the smoke emission of EGBE is reduced remarkably in comparison with commercial diesel fuel, that is, it can supply oxygen component sufficient at high load and speed in diesel engine. And, it was tried to analyze the quantities of the low and high boiling point hydrocarbon among the exhaust emissions in diesel engine. It have been investigated by the quantitative analysis of the hydrocarbon $C_1$~ $C_{6}$ using the gas chromatography. This study was carried out by comparing the chromatogram with diesel fuel and diesel fuel blended EGBE 20vo1-%. The results of this study show that the hydrocarbon $C_1$~C$_{6}$ among the exhaust emission of the mixed fuels are exhausted lower than those of the diesel fuel at the all load and speed. In particular, high boiling point hydrocarbons such as $C_{5}$ and $C_{6}$ were reduced remarkably at high speed and load.d.

• Polymer(Korea)
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• v.25 no.4
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• pp.568-574
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• 2001

PEO-like solid polymer electrolytes based on bisphenol A ethoxylate acrylate were synthesized and their electrochemical properties and mechanical stability were studied. Low molecular weight poly(ethylene glycol) dimethyl ether (PEGDMe) was added to increase the conductivity of the electrolyte. The maximum conductivity of the resulting polymer electrolyte was found to be 1.0 ${\times}$ 10$^{-3}$ S/cm [Bisphenol A ethoxylate diacrylate ([EO]/[phenol]= 15), PEGDMe250 80 wt%, LiCF$_3SO_3$] at 30$^{\circ}$C. Tensile strength of the free standing polymer electrolyte films was measured to be in the range of 0.4 ~ 5 MPa and these polymer electrolyte films did not show a crack even in 90$^{\circ}$ and 180$^{\circ}$ bending against ${\phi}$=3 mm bar. These electrolytes showed oxidation stability up to 4.5 V vs. lithium reference electrode.

• Polymer(Korea)
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• v.38 no.5
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• pp.671-675
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• 2014

Well-defined star shaped and linear block copolymers were synthesized to study the dispersion stability of copper phthalocyanine (CuPc). We synthesized dispersants using (2-dimethylamino) ethyl methacrylate (DMAEMA) and poly(ethylene glycol) methyl ether methacrylate) (PEGMA) by activators generated by electron transfer (AGET) atom transfer radical polymerization (ATRP). pDMAEMA-b-pPEGMA copolymers were characterized by GPC and NMR. Furthermore, we studied the effect of the dispersion stability of copper phthalocyanine by controlling the degree of polymerization of PEGMA as a stabilizing group. The 4-arm star shaped polymeric dispersant showed better dispersion stability of CuPc at $25^{\circ}C$ for 7 days.