• Membrane Journal
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• v.26 no.3
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• pp.173-178
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• 2016

In this short review, the polymer electrolyte membranes consisting of polymer and Ag salts were introduced and various approaches to solve the long-term stability were summarized. In particular, utilizing $AgNO_3$ as carriers with ionic liquid, the replacement of polymer matrix as poly(ethylene phthalate) (PEP) for strong coordinative interactions with Ag ions and the introduction of $Al(NO_3)_3$ to $polymer/AgBF_4$ complexes were introduced for long-term stable facilitated olefin transport membranes. For the polymer nanocomposite membranes, the role of electron acceptors as polarizer on the surface of AgNPs and the approach to solve the low permeance were introduced.

• Applied Chemistry for Engineering
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• v.30 no.4
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• pp.389-398
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• 2019

Hydrogen energy is not only a solution to climate change problems caused by the use of fossil fuels, but also as an alternative source for the industrial power generation and automotive fuel. Among hydrogen production methods, electrolysis of water is considered to be one of the most efficient and practical methods. Compared to that of the fossil fuel production method, the method of producing hydrogen directly from water has no emission of methane and carbon dioxide, which are regarded as global environmental pollutants. In this paper, the alkaline water electrolysis (AWE) and polymer electrolyte membrane water electrolysis (PEMWE), which are one of the hydrogen production methods, were discussed. Recent research trends of hydrocarbon electrolyte membranes and the crossover phenomenon of electrolyte membranes were also described.

• Korean Chemical Engineering Research
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• v.54 no.1
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• pp.36-43
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• 2016

Hydrosilylation reactions of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane with allyl butyrate catalyzed by Karstedt's, $H_2PtCl_6$ and Pt/C catalyst were studied and 2.4.6.8-tetra (propyl butyrate)-2.4.6.8-tetramethylcyclotetrasiloxane was obtained. The reaction order, activation energies and rate constants were determined. Ringopening polymerization of 2.4.6.8-tetra (propyl butyrate)-2.4.6.8-tetramethylcyclotetrasiloxane in the presence of $CaF_2$, LiF, KF and anhydrous potassium hydroxide in $60-70^{\circ}C$ temperature range was carried out and methylsiloxane oligomers with regular arrangement of propyl butyrate pendant groups were obtained. The synthesized products were studied by FTIR and NMR spectroscopy. The polysiloxanes were characterized by wide-angle X-ray, gel-permeation chromatography and DSC analyses. Via sol-gel processes of oligomers doped with lithium trifluoromethylsulfonate or lithium bis (trifluoromethylsulfonyl)imide, solid polymer electrolyte membranes were obtained. The dependences of ionic conductivity of obtained polyelectrolytes on temperature and salt concentration were investigated, and it was shown that electric conductivity of the polymer electrolyte membranes at room temperature changed in the range $3.5{\times}10^{-4}{\sim}6.4{\times}10^{-7}S/cm$.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.309-311
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• 2007

Supramolecules containing double hydrogen bonding sites at their both chain ends were self-polymerized to become solid state polymer and were utilized to improve the efficiency of solid state DSSCs. Hydrogen bonding sites were attached at the chain ends of PEG of Mw=2000, such as pyrimethamine and glutaric acid. The solar cell with the solid state supramolecular polymer electrolyte resulted in the overall energy conversion efficiency of 4.63 % with a short circuit current density $(J_{sc})$ of 10.41 $mAcm^{-2}$, an open circuit voltage $V_{oc}$, of 0.71 V and a fill factor (FF) of 0.62 at one sun condition ([oligomer]:[1-methyl-3-propyl imidazolium iodide (MPII)]:$[I_2]$ = 20 : 1 : 0.19, active area = 0.16 $cm^2$, $TiO_2$ layer thickness = 10 ${\mu}m$). The ionic conductivity of the sol id state electrolyte was $5.11{\times}10^{-4}$ (S/cm). The cell performance was characterized by electrochemical impedance spectroscopy and ionic conductivity.

• Macromolecular Research
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• v.15 no.5
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• pp.459-464
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• 2007

Polymer electrolyte membranes, featuring ionic channels, were prepared from sulfonated dextran/ poly(vinyl alcohol) (sD/PVA) membranes. A stiff sulfated dextran was chosen as the route for ionic transport, since ionic sites are located along the stiff dextran main chain. The sD/PVA blend membranes were annealed and then chemically crosslinked. The characteristics of the crosslinked sD/PVA membranes were investigated to determine their suitability as proton exchange membranes. The proton conductivity was found to increase with increasing amounts of sD inside the membrane, which reached a maximum and then decreased when the sD content exceeded 30 wt%, while the methanol permeability increased with increasing sD content. The good dispersion of sD inside the membrane, which serves as an ionic channels mimic, played a significant role in proton transportation.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2141-2142
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• 2010

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.05a
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• pp.233-238
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• 1999

고분자 연료전지 (polymer electrolyte membrane fuel cell (PEMFC)) 시스템은 연료전지 스택, 연료공급부, 공기공급부, 냉각부, 운전 제어부, 전자부하 및 데이터 획득부 그리고 인버터 등으로 구성된다. 이 가운데 가장 중요한 구성요소인 고분자 연료전지 스택의 성능은 전극과 전해질막 접합체의 성능뿐만 아니라 스택의 구조와 유로형상에도 크게 의존한다. 따라서 보다 고성능의 전해질막과 전극을 개발하고 소형화, 경량화가 가능한 스택의 구조와 유로형상을 찾는 것이 고분자 연료전지 스택의 개발에 있어 매우 중요하다.(중략)

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.608-612
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• 2012

We investigated the cycling behavior of $Li_4Ti_5O_{12}$ electrode in a cross-linked gel polymer electrolyte based on non-flammable ionic liquid consisting of 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide and vinylene carbonate. The $Li_4Ti_5O_{12}$ electrodes in ionic liquid-based gel polymer electrolytes exhibited reversible cycling behavior with good capacity retention. Cycling data and electrochemical impedance spectroscopy analyses revealed that the optimum content of the cross-linking agent necessary to ensure both acceptable initial discharge capacity and good capacity retention was about 8 wt %.

• Rubber Technology
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• v.13 no.1
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• pp.1-9
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• 2012

Click chemistry had enjoyed a wealthy decade after it was introduced by K.B.Sharpless and his co-worker on 2001. Since there is no optimized method for synthesis of click polymer, therefore, this paper introduced three click reaction methods such as catalyst, non-catalyst and azide-end capping for fluorene-based functional click polymers. The obtained polymers have reasonable molecular weight with narrow PDI. The polymers are thermally stable and almost emitted blue light emission. The synthesized fluorene-based functional click polymers were characterized to compare the effect of click reaction methods on polymer electro-optical properties as well as device performance on quasi-solid-state dye sensitized solar cells (DSSCs) applications. The DSSCs with configuration of $SnO_2:F/TiO_2/N719$ dye/quasi-solid-state electrolyte/Pt devices were fabricated using these click polymers as a solid-state electrolyte components. Among the devices, the catalyzed click polymer composed device exhibited a high power conversion efficiency of 4.62% under AM 1.5G illumination ($100mW/cm^2$).These click polymers are promising materials in device application and $Cu^I$-catalyst 1, 3-dipolar cycloaddition click reaction is an efficient synthetic methodology.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2355-2361
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• 2009

The current solid polymer electrolytes suffer from poor conductivity, low mechanical and electrochemical stability toward the lithium electrodes. To improve the performance of solid polymer electrolytes, the addition of nanoparticle fillers to the polymer electrolyte is being extensively investigated. In this paper, a brief review on the state of art of solid fillers for lithium battery electrolytes is presented.