• Bulletin of the Korean Chemical Society
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• v.27 no.7
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• pp.1043-1047
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• 2006

New electroluminescence polymer, poly(5,10-dihexyl-5,10-dihydroindolo[3,2-b]indole-2,7-diyl) (PININO) was synthesized by Yamamoto conditions with Ni(0) catalyst. The full characterization of structures and properties as well as the performances of the electroluminescence devices of the new polymer are presented. The resulting polymer, which exhibits good solubility in common organic solvents, was used as the electroluminescence layer for the light-emitting diodes (LEDs) (ITO/PEDOT/polymer/Al). PININO shows turn-on voltage of 2.5 V, and electroluminescence (EL) with maximum peak at 490 nm, maximum brightness of 40 cd/$m^{2}$ at 8 V, and efficiency of 0.002 cd/A at 350 mA/$cm^{2}$.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.299-302
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• 2005

Direct Borohydride Fuel Cell은 알칼리 붕소 수소화물의 수용액을 이용하는 연료전지로 연료의 직접 산화반응을 통해 기존의 DMFC(직접 메탄을 연료전지)보다 높은 전류밀도와 OUV(Open Circuit Voltage)를 나타낸다. 또한 액체 연료를 사용하므로 장치 구성이 간단하며, 사용하는 연료가 반응성이 높은 알칼리 붕소 수소화물로 이루어져 있기 때문에 탄화수소 계열의 액체 연료와 달리 전기화학 반응이 비귀금속 전극에서도 쉽게 이루어질 수 있다는 장점을 가지고 있다 하지만 강알칼리 조건에서 전기화학 반응이 진행되므로 이에 적합한 재료로 장치를 구성해야 하며, 액체 상태의 연료가 전해질을 투과하는 현상인 크로스오버 문제를 해결해야 하고, 생성물인 $BO_2$-가 침적되어 전지효율을 떨어뜨리는 것을 방지해야 하는 문제점이 있다. 또한 알칼리 붕소 수소화물이 물과 반응하여 수소를 발생시키는 hydrolysis 반응을 억제하여야 하고 직접 산화반응만이 진행될 수 있도록 전지를 구성해야 연료효율을 높일 수 있다. 따라서 본 연구에서는 수소 생성반응일 hydrolysis 반응은 억제하고 연료의 직접 산화반응만을 진행시키기 위한 전극촉매에 대하여 연구하였다. 일반적인 저온형 연료전지의 전극촉매로 사용하는 Pt등의 귀금속 촉매와, 귀금속 촉매를 대체할 수 있는 Ni등의 비귀금속 촉매를 그 연구 대상으로 하였으며, 평가 방법으로는 unit cell station을 이용한 단위전지 성능측정 실험과 Potentiostat/Galvanostat을 이용한 half cell 실험을 병행하여 수행하였다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.132-138
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• 2007

Carbon nanotubes (CNTs) arc grown on Ni catalysts employing an inductively-coupled plasma chemical vapor deposition (ICP-CVD) method. The structural and field-emissive properties of the CNTs grown are characterized in terms of the substrate-bias applied. Characterization using the various techniques, such as field-omission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Auger spectroscopy (AES), and Raman spectroscopy, shows that the structural properties of the CNTs, including their physical dimensions and crystal qualities, as well as the nature of vertical growth, are strongly dependent upon the application of substrate bias during CNT growth. It is for the first time observed that the provailing growth mechanism of CNTs, which is either due to tip-driven growth or based-on-catalyst growth, may be influenced by substrate biasing. It is also seen that negatively substrate-biasing would promote the vertical-alignment of the CNTs grown, compared to positively substrate-biasing. However, the CNTs grown under the positively-biased condition display a higher electron-emission capability than those grown under the negatively-biased condition or without any bias applied.

• Journal of the Korean Applied Science and Technology
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• v.17 no.3
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• pp.149-157
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• 2000

The synthesis of N-methyl glucamine was performed in two step reaction. The first step involves the amination between methylamine and glucose in methane. The N-methyl glucamine was obtained by the reduction of using Ni catalyst under the high pressure. The second step was glucamide anionic derivatives synthesis from N-methyl glucamine, maleic anhydride, lauryl alcohol and laurylamine by Schotten Banmann reaction respectively. Their molecular structures of N-methyl glucamine and glucamide (EG-MAS and AC-MAS) were investigated by IR and $^{1}H-NMR$. Basic physical properties and biodegradability of there glucamide anionic surfactant was investigated. The range of cmc values determined by measurements of surface tention was $10^{-5}{\sim}10^{-4}mol/l$ and the surface tension of the aqueous solution revealed in the range $28{\sim}30$ dyne/cm and their biodegradability was very good in the pH $5{\sim}10$.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.5
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• pp.473-481
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• 2007

Compared to other types of fuel cells, SOFC has advantages like a wide output range and the direct use of hydrocarbon fuel without the process of external reforming. Particularly because the direct use of fuel without reforming reaction is closely linked to overall system efficiency, it is a very attractive advantage. We tried the operation with methane. However, although methane has a small number of carbons compared to other hydrocarbon fuels, our experiment found the deposition of carbon on the surface of the SOFC electrode. To overcome the problem, we tried the operation through activating internal reforming. The reason that internal reforming was possible was that SOFC runs at high temperature compared to other fuel cells and its electrode is made of Ni, which functions as a catalyst favorable for steam reforming.

• Journal of Hydrogen and New Energy
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• v.15 no.2
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• pp.152-158
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• 2004

Hydrogen has been considered as an important and essential future energy source. But the storage of the hydrogen is a difficult problem and many studies were focused on this matter. However, the MTH-system (methylcyclohexane, toluene, hydrogen) was proposed for storage of hydrogen by Taube et al. and that is the reaction of hydrogen with toluene to give methylcyclohexane. One toluene molecule can store six hydrogen atoms to form methylcyclohexane. In this form the hydrogen can be easily stored in liquid organic hydrides and transported at ambient pressure in tanks. Hence, this study is focused on the catalytic dehydrogenation of methylcyclohexane. Since supported platinum and nickel were employed as catalysts in literature, in this study, porous Pt and Ni were prepared and tested for the dehydrogenation reaction. When the porous Pt catalyst was applied to the dehydrogenation it showed higher activity in the reaction and higher selectivity to toluene. Specially at higher pressure, it showed almost 100 % conversion and 100 % selectivity and hence porous platinum could be considered as best for the given reaction.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.73.2-73.2
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• 2011

합성천연가스(SNG: Synthetic Natural Gas)를 얻기 위해, 석탄 가스화로부터 얻은 합성가스는 일반적으로 수소와 일산화탄소의 비가 3.0($H_2$/CO)이 되도록 수성가스전환(WGS)반응을 거친 후 메탄화반응기로 유입되며, 가능하면 낮은 온도에서 메탄 전환율이 높은 메탄화 반응의 특성상 강한 발열반응이 수반되므로 이를 낮추는 것이 중요하다. 또한, 최종생성물내의 메탄 농도를 높이기 위해 WGS 이후 탈황과 동시에 이산화탄소를 제거하기 위한 공정이 요구된다. 본 연구에서는 정제된 합성가스의 WGS와 이산화탄소 제거가 생략된 공정을 개발하기 위해, 상업용 촉매에 대하여 수소의 농도가 낮은 합성가스를 이용하여 스팀과 이산화탄소에 대한 메탄화반응 특성을 평가하였다. 또한, 이산화탄소의 존재여부에 따라 스팀으로 메탄화반응과 WGS가 동시에 일어날 수 있는 최적의 운전조건을 얻고자 하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.579-579
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• 2012

Graphene has recently been a subject of much interest as a potential platform for future nanodevices such as flexible thin-film transistors, touch panels, and solar cells. And chemical vapor deposition (CVD) and related surface segregation techniques are a potentially scalable approach to synthesizing graphite films on a variety of metal substrates. The structural properties of such films have been studied by a number of methods, including Raman scattering, x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and transmission electron microscopy (TEM). An understanding of the structural quality and thickness of the graphite films is of paramount importance both in improving growth procedures and understanding the resulting films' electronic properties. In this study, we synthesized the few-layered grapheneunder optimized condition to figure out the growth mechanism seen in CVD-grown graphenee by using various electron microscope. Especially, we observed directly film thickness, quality, nucleation site, and uniformity of grpahene by using AEM. The details will be discussed in my presentation.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1995.05a
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• pp.129-132
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• 1995

상압의 유동층반응기 (0.1 m-i.d x 1.6 m-high) 에서 호주탄을 수증기와 공기를 사용하여 가스화 하였다. 또한 반응기에서 촉매효과를 고찰하기 위해 $K_2$SO$_4$+Ni(NO$_3$)$_2$ 촉매를 호주탄에 담지하여 가스화반응을 수행하였다. 생성가스조성, 생성가스량, 탄소전환율, cold gas efficiency 및 발열량 등에 대한 유동화속도 (2~5U$_{mf}$), 반응온도 (750~90$0^{\circ}C$), 공기/석탄 비 (1.6~3.2), 수증기/석탄 비 (0.63~l.26)의 영향을 조사하였다. 탄소전환율, 생성 가스량, 생성가스 발열량 및 cold gas efficiency 는 유동화속도와 반응온도의 증가에 따라 증가하였다. 공기/석탄 비가 증가함에 따라 탄소전환율과 생성가스량 및 cold gas efficiency 는 증가하지만 생성가스 발열량은 감소하였다. 수증기/석탄 비의 증가에 따라 발열량, cold gas efficiency 및 생성가스량은 증가하였으며, 탄소 전환율은 거의 일정하였다. 촉매 가스화반응에서 유동화속도, 반응온도, 공기/석탄 비 및 수증기/석탄 비의 증가에 따라 탄소 전환 율, 생성가스량, 생성가스 발열량 및 cold gas efficiency 는 크게 향상됨을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3221-3224
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• 2010

This study investigates the requirements of lithium-air cathodes, which directly influence discharge capacity. The cathodes of Li-air cell are made by using five different carbon materials, such as Ketjen black EC600JD, Super P, Ketjen black EC300JD, Denka black, and Ensaco 250G. The Ketjen black EC600JD provides discharge capacity of 2600 mAh/g per carbon weight, while that of Ensaco 250G shows only 579 mAh/g. To figure out the differences of discharge capacity from carbon materials, their surface area and pore volume are analyzed. These are found out to be the critical factors in determining discharge capacity. Furthermore, carbon loading on Ni foam and amounts of electrolyte are significant factors that affect discharge capacity. In order to investigate catalyst effect, electrolytic manganese dioxide (EMD) is incorporated and delivered 4307 mAh/g per carbon weight. This infers that EMD facilitates to break $O_2$ interactions and leads to enhance discharge capacity.