• 한국세라믹학회지
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• 제32권2호
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• pp.248-256
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• 1995

The electrical conducton in the sintered 3Bi2O3.WO3 solid electrolyte was investigated by measuring the conductivity and ionic transport number. The electrical conductivity was about three to ten times higher than that of YSZ at temperatures between 300 and 80$0^{\circ}C$. D.C. polarization method confirmed that 3Bi2O3.WO3 was predominantly an ionic conductor. Unlike the instability of high conductive fcc phase in the rare-earth oxide-Bi2O3 or Y2O3-Bi2O3 systems at temperature below $700^{\circ}C$, fcc phase in the 3Bi2O3.WO3 exhibited no transformation even after annealing over 900 hrs at 600 and $650^{\circ}C$. Two samples which had different grain sizes showed almost the same conductivity. This result suggests that the electrical properties of grain and grain boundry were very similar.

• The Korean Journal of Ceramics
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• 제4권2호
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• pp.141-145
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• 1998

The electrical properties of the mixed conducting yttria(8 mol%) stabilized zirconia(YSZ)-nickel oxide(NiO) composites were examined by a.c. impedance, 4-probe d.c. conductivity between 400 and $1000^{\circ}C$. The oxygen partial pressure dependence of conductivity, and electromotive force measurement of galvanic cell enabled to determine the electronic contribution to the conduction. Up to 6 vol% NiO addition, the conductivity decreased since the electronic NiO acted as an insulator in ionic matrix. However the ionic transport was dominant until NiO content reaches 26 vol%. Mixed conduction was observed between 26 and 68 vol% of NiO. The effect of composition on the electrical property was explained by the microstructure and thus by the distribution of two phases.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.146-147
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• 2008

Poly(3,4-ethylenedioxythiophene) (PEDOT) / poly(1-vinyl-3-ethylimidazolium bis(trifluoromethane sulfonyl)imide) (poly(ViEtIm $^+TFSI^-$) complex was prepared for organic solvent dispersible conductive nano particles. By molar ratio, PEDOT / poly(ViEtIm $^+TFSI^-$) complex was polymerized and dispersed in propylene carbonate by 1 wt%. The maximum conductivity of the complexes was $1.2\times10^{-1}$ S/cm.

• Journal of the Korean Wood Science and Technology
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• 제25권4호
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• pp.10-16
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• 1997

This study was carried out to improve coating structure by controlling the electrostatic interaction of coating components and by changing the coating structure of coated paper prepared with amphoteric and anionic latices. The results indicated that amphoteric latex copolymerized with carboxylic and amine groups had stronger interaction with other coating components than anionic latex with branched carboxylic group by controlling pH. These properties of amphoteric latex showed positive effects on viscosity rheology, and supernatant sediment of coating color. The coated paper using amphoteric latex had also produced more porous and smoother coverage of the coating layer than that using anionic latex. This porous and smooth coating layer showed better optical properties and printability than those of anionic latex such as opacity, porosity, ink set-off, and wet ink receptivity.

• Bulletin of the Korean Chemical Society
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• 제14권2호
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• pp.215-220
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• 1993

Experiment on isomorphous substitution of Al by Fe in sodalite framework was carried out using dry way method at 800-900$^{\circ}$C in nitrogen atmosphere. The substitution of Fe was possible up to 25 mole% with some deviation of symmetry in sodalite cage. The cubic unit cell parameter increased with increasing Fe content. It showed ionic semiconducting property, especially the highest conductivity and the lowest activation energy in 10 mole% Fe-substituted sodalite which could behave as a superionic conductor at above 400$^{\circ}$C. When more Fe was introduced into sodalite the electronic conductivity was improved at high temperature. But the relative electronic contribution was found to be lower compared with ionic contribution at high temperature. In infrared spectra some major absorption bands of sodalite shifted to lower wave numbers due to heavier Fe atoms substitution in Al lattice sites.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.133-136
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• 2007

Perovskite-structured samarium strontium cobaltite (SSC), which is mixed ionic electronic conductor (MIEC), is considered as a promising cathode material for intermediate temperature-operating solid oxide fuel cell (SOFC) due to its high electrocatalytic property. Cathode material containing cobalt (Co) is unstable at high temperature and has a relatively high thermal expansion property. In this paper, Sm-Sr-(Co,Fe,Ni)-O system with perovskite and spinel structures was investigated in terms of electrochemical property and thermal expansion property, respectively. Area specific resistance (ASR) was measured by ac impedance spectroscopy to investigate the electrochemical property of cathode, and thermal expansion coefficient (TEC) was measured by using dilatometer. Micro structure of cathode was observed by scanning electron microscopy. Perovskite-structured $Sm_{0.5}Sr_{0.5}CoO_{3-\delta}$ showed the ASR of $0.87{\Omega}/cm^{2}$, and $Sm_{0.5}Sr_{0.5}NiO_{3-\delta}$, which actually has a spinel structure, showed the lowest TEC value of $13.3{\times}10^{-6}/K$.

• 폴리머
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• 제24권2호
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• pp.259-267
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• 2000

겔형 고분자 전해질에 적용 가능한 고분자 매트릭스 중 우수한 기계적 성질 및 높은 유전상수 ($\varepsilon$=8~13)를 가지는 poly(vinylidene fluoride-co-hexafluoro propylene)[P(VdF-co-HFP)]을 사용하고, Ethylene carbonate (EC)/${\gamma}$-butyrolactone (${\gamma}$-BL)의 혼합용매와 LiCF$_3$SO$_3$를 각각 유기용매와 리튬염으로 사용하여 다양한 농도의 전해액 및 겔형의 고분자 전해질을 제조하였다. 제조된 고분자 전해질의 기계적 성질 및 이온전도도를 고분자 매트릭스와 전해액의 흔합비율에 따라 측정하였다. 28.6 wt%의 P(VdF-co-HFP)가 함유된 PVH40이 $25^{\circ}C$에서 1.09$\times$$10^{-3}$S/cm의 가장 높은 이온전도도 값을 보였고, 인장강도, 인장탄성율, 압축탄성율 모두 P(VdF-co-HFP)의 함량에 따라 증가했으며 PVH70과 PVH80사이에서 급격한 변화를 나타내었다. 동역학적 특성측정 시 전형적인 겔의 거동을 보였고, 적용한 변형의 크기에 따라 저장탄성율(G')과 손실탄성율 (G")이 변화되었다.

• Carbon letters
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• 제17권1호
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• pp.70-73
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• 2016

• 대한화학회지
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• 제52권6호
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• pp.676-683
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• 2008

• Korean Chemical Engineering Research
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• 제50권4호
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• pp.708-712
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• 2012

이온성 액체는 일반적으로 거대 헤테로 고리 양이온과 무기 음이온으로 이루어진 염으로, 상온에서 액체로 존재한다. 따라서 이온성 액체의 물성은 양이온과 음이온의 종류, 알킬기의 수에 영향을 받으므로 그 조합에 의해 이온성 액체 각각의 물성이 달라진다. 또한 비휘발성, 열적 안정성, 넓은 전기 화학적 범위를 가지므로 기존의 유기용매를 대체할 주목할 만한 청정 용매(Green solvent)이다. 본 연구에서는 1-Butyl-3-methylimidazolium bromide ([BMIM][Br]), 1-butyl-3-methylimidazolium Chloride ([BMIM][Cl]), 1-butyl-3-methylimidazolium iodide ([BMIM][I]) 그리고 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][$BF_4$])을 합성하였으며, 그 중 [BMIM][Br], [BMIM][I], [BMIM][$BF_4$]의 밀도, 점도, 굴절률, 열용량과 이온전도도를 293.2~323.2 K의 온도범위에서 측정하였다. 밀도와 굴절률은 [BMIM][I]가 세 이온성 액체 중 가장 높았으며, 점성은 [BMIM][Br]가 가장 높았다. 열용량은 [BMIM][Br]보다 [BMIM][$BF_4$]가 높았으며, 이온 전도도는 [BMIM][I]보다 [BMIM][$BF_4$]가 더 높았다.