• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.49.1-49.1
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• 2010

본 연구에서는 증착법에 의해 제조된 다결정 실리콘을 이용한 태양전지 제작과 관련하여 다결정 실리콘 씨앗층 제조를 위한 기판에 대하여 연구를 수행하였다. 다결정 실리콘 씨앗층을 제조할 수 있는 기술중 aluminum-induced layer exchange(ALILE) 공정을 이용하여 다결정 실리콘 씨앗층을 제조하였다. glass/Al/oxide/a-Si 구조로 알루미늄과 비정질 실리콘 계면에 알루미늄 산화막을 다양한 두께로 형성시켜, 알루미늄 유도 결정화에서 산화막의 두께가 결정화 특성에 미치는 영향, 결정결함, 결정크기에 대하여 연구하였다. 형성된 다결정 실리콘 씨앗층 막의 특성은 OM, SEM, FIB, EDS, Raman spectroscopy, XRD, EBSD 을 이용하여 분석하였다. 그 결과 산화막의 두께가 증가할수록 결함도 함께 증가하였다. 16nm 두께의 산화막 구조에서 <111> 방향의 우선배향성을 가진, $10{\mu}m$의 sub-grain 결정립을 갖는 씨앗층을 제조 하였다.

• Korean Chemical Engineering Research
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• v.45 no.5
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• pp.506-514
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• 2007

To select the best oxygen carrier particle for syngas fueled chemical-looping combustor, the reduction reactivity and carbon deposition characteristics were determined in a thermogravimetric analyzer. Four kinds of oxygen carrier particles (NiO/bentonite, $NiO/LaAl_{11}O_{18}$, $Co_xO_y/CoAl_2O_4$, $NiO/NiAl_2O_4$) were tested with the simulated syngas (30% $H_2$, 10% $CO_2$, 60% CO) as a reduction gas. With each of these particles, the maximum conversion and oxygen transfer capacity increase with increasing the reduction temperature At the given experimental range, the optimum operating temperature to maximize oxygen transfer rate is found to be $900^{\circ}C$ and carbon deposition on the particles could avoid at the temperature above $800^{\circ}C$. Among four kinds of oxygen carrier particles, the NiO-based particles exhibits better reactivity than the CoO-based particle. Moreover, the NiO/bentonite particle produces the best reactivity based on the oxygen transfer rate and the degree of carbon deposition. The measured oxygen transfer rate increases as the metal oxide content in NiO/bentonite particle is increased thereby higher metal oxide contents could provide stable operation of chemical-looping combustor.

• Applied Chemistry for Engineering
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• v.27 no.3
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• pp.227-238
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• 2016

This review article highlights different types of nano-sized catalysts for the selective alcohol oxidation to form aldehydes (or ketones) with supported or immobilized metal nanoparticles. Metal nanoparticle catalysts are obtained through dispersing metal nanoparticles over a solid support with a large surface area. The nanocatalysts have wide technological applications to industrial and academic fields such as organic synthesis, fuel cells, biodiesel production, oil cracking, energy conversion and storage, medicine, water treatment, solid rocket propellants, chemicals and dyes. One of main reactions for the nanocatalyst is an aerobic oxidation of alcohols to produce important intermediates for various applications. The oxidation of alcohols by supported nanocatalysts including gold, palladium, ruthenium, and vanadium is very economical, green and environmentally benign reaction leading to decrease byproducts and reduce the cost of reagents as opposed to stoichiometric reactions. In addition, the room temperature alcohol oxidation using nanocatalysts is introduced.

• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.36-38
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• 2012

본 연구는 석탄계 핏치를 원료로 하여 구형 활성탄소를 제조하여 독성 물질인 Dimethyl Methlphosphonate, Hydrogen Chloride에 대한 흡착과파 특성을 연구하였다. 본 연구에서 적용된 구형활성탄 제조방법은 피치를 이용하여 제조하였다. 제조방법은 원료 핏치의 연화점을 상승시키는 전처리 과정, 상기 전처리된 원료 핏치 용융물을 수용액에 현탁시켜 구형입자로 성장시키는 구형화 과정, 구형입자를 산화, 탄화 및 활성화하는 과정으로 구성되며 첨착 활성탄소에 첨착되는 첨착물질의 성분 및 첨착방법의 변화에 따른 독성가스의 흡착성능을 관찰하기 위하여 Dimethyl Methlphosphonate와 Hydrogen Chloride 가스를 대상으로 열중량반응기를 이용하여 흡착실험을 수행하였다. 최적의 담지체 선정을 위하여 담지금속에 따른 흡착능을 시험하여 최적 금속과 함침량을 도출하였다.

• Transactions of the Korean hydrogen and new energy society
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• v.16 no.3
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• pp.269-276
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• 2005

Zn, Bi 와 V 금속이온 전구체를 사용하여 모노클리닉 결정구조를 갖는 신규 ZnBiVO4 광촉매를 손쉽게 합성 할 수 있는 방법을 개발하였다. 합성된 $ZnBiVO_4$ 광촉매는 XRD 과 FESEM등을 이용하여 미세구조를 분석하였으며, 분석결과 본 삼성분계 금속산화물 반도체 광촉매는 모노클리닉 결정구조를 갖는 것을 알 수 있었다. 저온 수용액방법에 의해 손쉽게 나노 구조를 갖는 $ZnBiVO_4$가 제조되었으며, 그 광촉매의 최소 입자크기는 20-30 nm 이다. $ZnBiVO_4$ 광촉매는 UV-visible DRS (diffuse reflectance spectroscopy)로 그 띠간격(band gap)을 측정하였으며, FT-IR을 사용하여 구조 및 물질 상의 순도를 확인하였다. 그리고 $H_2S$를 광분해하여 수소를 발생하는($122ml/hr{\cdot}g$) 우수한 광촉매 활성을 보여 주었다.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1988.06a
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• pp.31-38
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• 1988

최근, 유체윤활영역에 있어서 될수 있는 한 점성저항을 감소시키기 위해서 윤활유의 저점도화가 진행되고 있는 실정이다. 그러나 윤활유의 저점도화로 인한 문제점으로써 금속-금속간 접식부가 증가하게 된다. 금속간 접식이 증가함에 따라 마찰저항이 커지게 되며, 이와 같은 마찰저항의 증대를 방지하기 위하여 마찰조정제(FM)가 자동차 엔진유를 비롯한 각종 윤활유에 첨가되어지고 있다. 또한 윤활유의 사용조건이 가곡(고온, 고가중) 해짐에 따라 첨가제의 다기능성이 요구되고 있는 가운데, 이와 같은 요구를 만족시켜 주기 위한 연구가 진행되고 있다. 최근에 와서 유용성 유기모리브덴계 화합물이 마찰,마모 및 산화방지제로서 주목받고 있다. 마찰, 마모을 감소시키기 위한 목적으로 널리 사용되고 있는 $MoS_2$는 고체윤활제로서 각광을 받고 있지만, 실제사용상의 문제로서 입자의 크기, 분산상의 문제 및 분산제와의 반응으로 인하여 마찰, 마모를 증대시키므로 역효과를 가져 오기도 한다. $MoS_2$와 같은 고체윤활제의 분상상의 무제점을 보완한 유용성 모리브덴계 화합물은 마찰, 마모 및 산화방지제로서 자동차 엔진유를 비롯하여 각종 윤활유에 첨가되고는 있지만 메카니즘에 대해서는 거의 해명되고 있지 않는 현실정이다. 본 연구는 유용성 유기모리브덴계 화합물중의 Molybdenum dialkyl dithiophosphate (MoDTP)의 마찰감소작용을 해명하기 위해서, MoDTP 첨가제의 마찰시험 및 마찰표면의 분석을 통하여 MoDTP의 마찰감소작용의 메카니즘을 명확하게 함을 자적으로 하고 있다.

• Journal of the Korean Vacuum Society
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• v.18 no.4
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• pp.281-287
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• 2009

Pd was deposited on magnesium-oxide-covered magnesium ribon substrate by metal thermal evaporation method in high vacuum. The electronic and chemical properties of Pd samples with different coverages were studied using in-situ X-ray Photoelctron Spectroscopy (XPS) and Field Emission Scanning Electron Microscopy (SEM). For relatively lower amounts of Pd deposited(< 1nm), separate Pd particles could be observed, whereas at higher Pd coverages, Pd thin films caused by agglomeration of Pd nanoparticles was found. The metal support interaction with Pd-support was observed. The Pd atoms on the metal oxide/metal interface were partially negative charged by charge transfer.

• Resources Recycling
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• v.5 no.1
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• pp.14-20
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• 1996

For recycl~ng alumhx~rn dross, the cbaraclcrislics of dross and ils reutll~zalin~af~te r plocsssing should he considered. Nurn~llumd ross was classified according to iB sire in this shldy. Tbe dross larger Illan 3001~1w as directly re-meltcd to recover aluminum, and the s~nallerd ~ossw as leachcd and riln~tedl o scparalc 111s eri~lerls alt and to oxidize the rnelals contained in the dross. As a rcwlt, amount of the dross uscd lo be dircarded ahcr processing could hc reduced Also, lhc chem~cal culnposit~ons of a domzstic alumlnum dross and the changes in con~posilii~ndsu ring processings were investigated. and Cound that most mctaU'ic aluminum in the dross was changed inlu alu~n~numox ide lhruugli the roasting. Tile processed dross would he ulillzed for malerials such as alumina, alumma cemenl or tilcs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1555-1562
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• 2015

Metal oxide semiconductors have been applied in several areas, such as solar cells, sensor, optical elements and displays, due to the high surface area, unique electrical and optical characteristics. Zinc oxide among the metal oxide has excellent physicochemical properties. Zinc oxide is a n-type semiconductor with a wide direct transition band gap of 3.37 eV at room temperature and large exciton binding energy of 60 meV. Cation-doped zinc oxide studies were conducted to complement the electrical and optical characteristics. In this paper, Al-doped ZnO was synthesized by hydrothermal synthesis using microwaves. ZnO was synthesized by adjusting the precursor ratio and using different dopants. The optimal ZnO synthesis conditions for crystal shape and optical properties were determined. The optical properties of aluminum doped zinc oxide were then examined by SEM, XRD, PL, UV-vis absorbance spectrum, and EDS.

• Journal of the Korean Chemical Society
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• v.38 no.2
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• pp.92-100
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• 1994

Ultrafine cobalt-substituted iron oxide particles were prepared by the thermal decomposition and oxidation of the new organometallic precursor, $Co_xFe_{1-x}(N_2H_3COO)_2(N_2H_4)_2$ (x = 0, 0.01, 0.02, 0.03, 0.05, 0.10, 1.00). The organometallic precursors were synthesized by the reaction of Co(II) and Fe(II) ion in a mole ratio of x : 1-x with hydrazinocarboxylic acid, and characterized by quantitative analysis, elemental analysis and infrared spectroscopy. The mechanistic study on the thermal decomposition of the organometallic precursors was performed by TG-DTG and DSC. The cobalt-substituted iron oxide particles were obtained by the heat treatment of the precursors at $350^{\circ}C$ and $450^{\circ}C$ for six hours in air. The prepared iron oxide was found to have two phases such as ${\gamma}-Fe_2O_3$ and a mixture of ${\gamma}-Fe_2O_3\;and\;{\alpha}-Fe_2O_3$ at $350^{\circ}C$ and $450^{\circ}C$ respectively. The particle shape was equiaxial and the particle size was less than 0.05 ${\mu}m.$ The coercivity and squareness of the cobalt substituted iron oxide particles increased with increasing cobalt content. Both coercivity and squareness showed higher values at $450^{\circ}C.$