• Title, Summary, Keyword: Decal method

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Decal Method with High Catalyst Transfer Ratio and Its Performance in PEMFC

  • Park, Hyun-Seo;Cho, Yong-Hun;Cho, Yoon-Hwan;Sung, Yung-Eun
    • 한국신재생에너지학회:학술대회논문집
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    • pp.169-171
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    • 2007
  • A breaking layer was introduced to conventional decal transfer method in membrane electrolyte assembly fabrication for high catalyst transfer ratio. In this study, the modified decal transfer method with high catalyst transfer ratio was introduced and its performance is studied. The structural features of electrodes made by decal method were investigated using scanning electron microscopy and current-voltage polarization measurement.

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Development of a MEA Made by Decal Method in PEM Fuel Cells (데칼법을 이용한 연속 제조 공정에서의 고분자 전해질 연료전지용 전극 개발)

  • Yim, Sung-Dae;Park, Seok-Hee;Yoon, Young-Gi;Yang, Tae-Hyun;Kim, Chang-Soo
    • New & Renewable Energy
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    • v.6 no.1
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    • pp.46-52
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    • 2010
  • Membrane electrode assemblies (MEAs) for proton exchange membrane fuel cells (PEMFCs) have been extensively studied to improve their initial performance as well as their durability and to facilitate the commercialization of fuel cell technology. To improve the MEA performance, particularly at low Pt loadings, many approaches have been made. In the present study, MEA performance improvement was performed by adding $TiO_2$ particles into the catalyst layer of MEA. Most of previous studies have focused on the MEA performance enhancement under low humidity conditions by adding metal oxides into the catalyst layer mainly due to the water keeping ability of those metal oxides particles such as $Al_2O_3$, $SiO_2$ and zeolites. However, this study mainly focused on the improvement of MEA performance under fully humidified normal conditions. In this study, the MEA was prepared by decal method aiming for a continuous MEA fabrication process. The decal process can make very thin and uniform catalyst layer on the surface of electrolyte membrane resulting in very low interfacial resistance between catalyst layer and the membrane surface and uniform electrode structure in the MEA. It was found that the addition of $TiO_2$ particles into the catalyst layer made by decal method can minimize water flooding in the catalyst layer, resulting in the improvement of MEA performance.

Effects of Nafion Contents on the Performance of MEAs Prepared by Decal-Transfer Method (Nafion 함량이 데칼전사기법을 통해 제작된 고분자 전해질 연료전지의 MEA 성능에 미치는 영향)

  • Kim, Gyeong-Hee;Cho, Eun-Ae;Han, Jong-Hee;Kim, Sung-Hyun;Eom, Kwang-Sup
    • Transactions of the Korean hydrogen and new energy society
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    • v.23 no.2
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    • pp.125-133
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    • 2012
  • Nafion ionomer located in electrode helps to increase the platinum utilization and proton conductivity. To achieve higher performance in PEMFCs, it is important an optimum Nafion content in the electrode. As the platinum loading and fabricated method depend on the optimum Nafion content. In this study, we have examined the interrelationship between platinum loading and Nafion content fabricated by decal transfer method. For electrodes with 0.25 and 0.4 mg/$cm^2$ Pt loading, best performance was obtained at 25 wt.% Nafion ionomer loading. It is also found that MEA with 0.25 mg/$cm^2$ Pt, the optimum Nafion content appears differently at low and high current density.

Development of High Performance MEA by Decal Method for PEM Fuel Cell (데칼 공정을 적용한 고성능 MEA 개발)

  • Lee, Ki-Sub;Lee, Jae-Seung;Kwon, Nak-Hyun;Hwang, In-Chul
    • Transactions of the Korean hydrogen and new energy society
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    • v.22 no.5
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    • pp.585-591
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    • 2011
  • This study has focused on the development of high performance membrane-electrode assemblies (MEAs) fabricated by decal method for proton exchange membrane fuel cell (PEMFC). To study the effect of ionomer contents on performance, we fabricated MEAs with several electrodes which were prepared by varying the quantity of ionomer from 20 wt.% to 45 wt.% in catalyst layer. The MEA performance was obtained through single cell test. The MEA prepared from electrode with 25wt.% of ionomer showed the best performance. We evaluated the surface area and pore volume of electrode with BET. We found that the surface area and pore volume in electrode decreased rapidly at the electrode with 40wt.% of ionomer in catalyst layer. MEA was fabricated by roll laminator machine and the roll laminating conditions for the preparation of MEA, such as laminating press, temperature and speed, were optimized. The MEA performance is not affected by laminating temperature and speed, but roll laminating press have a great effect on MEA performance.

enhanced performance of Membrane electrode assembly made by decal method (데칼법으로 제조된 고분자 연료전지용 전극 막 접합체의 성능평가)

  • Ryu, S.K.;Park, S.H.;Yoon, Y.G.;Lee, W.Y.;Kim, C.S.
    • 한국신재생에너지학회:학술대회논문집
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    • pp.65-68
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    • 2007
  • 전극 막 접합체를 만드는 방법 중 연속식 공정으로서의 데칼법의 장점은 제조공정의 단순화와 두께 균일성 그리고 대량생산 등을 그 예로 들 수 있다. 본 실험에서는 코터를 이용해 전극 막 접합체를 만들기 위해 높은 점도의 촉매 슬러리를 제조하였다. Johnson Mattey 사의 HiSPEC 40 wt% Pt/C 촉매와 Dupont사의 20 wt% Nafion Solution 그리고 물을 이용하여 촉매 슬러리를 제조한 후 코터를 이용하여 데칼법으로 전극 막 접합체를 제조하였다. 완성된 전극 막 접합체의 성능 평가를 실시하였으며 상용화된 전극 막 접합체와 그 특성을 비교 분석을 실시해보았다.

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Fabrication of Hydrocarbon Membrane based DMFC MEAs with Low Temperature Decal Method (탄화수소계 전해질막과 저온 전사법을 이용한 DMFC용 MEA 제조)

  • Krishnan, N. Nambi;Prabhuram, Joghee;Ha, Heung-Yong;Kim, Soo-Kil
    • 한국신재생에너지학회:학술대회논문집
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    • pp.415-417
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    • 2009
  • A low temperature decal (LTD) transfer method is tried to fabricated hydrocarbon (HC) membrane based MEA. Sandwiched structures of outer ionomer/catalyst/carbon coating/substrate, which had been developed for Nafion membrane, are used for transfer of catalyst to the HC membrane. Performances of the HC MEA before and after 500hr continuous operation are compared and it is found that a severe delamination occurs at the interface between the HC membrane and the catalyst layer, which is the main reason of the low performance and its degradation. The delamination is due probably to the different nature of HC membrane to the Nafion ionomer. A substitutional method, therefore, is suggested to overcome this. In such a way, the outer ionomer process is removed and the low transfer rate of catalyst by skipping the ionomer process is compensated with optimization of other process variables such as transfer time or temperature. The resulting performance is superior to the original LTD method, which can be explained in terms of low resistive components both in ohmic and kinetic.

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A Study on Nail Art Applying the Paranoiac Critical Method of Salvador Dali (살바도르 달리(Salvador Dali)의 회화에 나타난 편집광적 비판방법(Paranoiac Critical Method)을 활용한 네일아트에 관한 연구)

  • Jeong, Seung-Eun;Kim, Jeong-Mee
    • Journal of the Korea Fashion and Costume Design Association
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    • v.16 no.2
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    • pp.151-161
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    • 2014
  • This study suggests method of expression of nail art utilizing Salvador Dali's Paranoiac Critical Method and produced the actual works based on discussions on Salvador Dali's painting, Paranoiac Critical Method, Nail Art's artistry and technique of expression. The result of the study is as follows: 1) Characteristic of Dali's painting is a Paranoiac Critical Method. If suggesting this characteristic in a method of expression of nail art, a good work which can be expressed on a small space, a nail, representing Dali is selected and 5 tips which are very similar to the rate of the painting are used in order to obtain an aesthetic effect just like a painting. And after composing on tips using the whole paining or part of painting, actual techniques of expression such as Hand Painting, Protranse or Water Decal are used. 2) the result of nail art produced utilizing Dali's Paranoiac Critical Method is as follows. Most of all, for nail art I with the topic of "The Persistence of Memory" (1931), after giving changes to 5 tips for the watch which is a part of the painting, Hand Painting technique is used using Acrylic Painting with colors which are similar colors to the painting. Then for nail art II which adopted "Slave Market with Invisible Bust of Voltaire" (1940), the whole painting is divided into 5 tips and Protranse technique which attaches printed paper onto nails was used. Lastly, for nail art III with the subject of "The Enigma of Desire My Mother, My Mother, My Mother" (1929), Water Decal which is emphasizing the parts of the painting and composing on 5 tips and copying printed picture onto Water Transfer Paper in order to attach on the nails is used. These nail arts show aesthetic characteristics such as fantasy, unconsciousness, grotesque, infinity, non-realism and horror just like paintings.

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A Study on Expression Techniques of Nail Art: Focused on Nail Holic in 2012

  • Kim, Jeongmee;Jeong, Seungeun
    • Journal of Fashion Business
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    • v.18 no.6
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    • pp.100-115
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    • 2014
  • This study examined the history of nail art in 20th century, defined characteristics of many techniques used on nails, and analyzed how those techniques have been utilized in recent nail art works. For the method of the study, books and previous studies on nail art were examined as primary sources, and newspaper articles on nail art were studied as references. Then, the case studies were conducted on photographs of nail art works published in Nail Holic in 2012. As a result of analyzing expression techniques of nail art featured on Nail Holic, there had been a total of 517 works created using a single technique. The reason why hand painting is used very frequently is because artists can draw unique images of their own to create various designs according to their tastes. Rhine stone is also very popular, because stones are easy to apply and various in their shapes and colors. There were a total of 555 works created using two or more techniques. The most important point to examine is that hand painting, rhine stone, and 3D art were most popular among all techniques. These works featured highly various effects and images by combining flat effect of hand painting with three-dimensional effects of rhine stone or 3D art. The tendency can also be found in the fact that there have been many works using techniques of flat effects such as decal or marbling combined with techniques of three-dimensional effects such as rhine stone or 3D art.

Control of Pretilt Angle using a in-situ Photoalignment Method on Photo-crosslinkable Polymer Surface (광중합 가능한 폴리머 표면에 in-situ 광배향법을 이용한 프리틸트각 제어)

  • 정은아;황정연;서대식;김재형;한은주
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.350-353
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    • 2001
  • Aligning capabilities for nematic liquid crystal (NLC) using a in-situ photodimerization method on various Photo-crosslinkable polyimide (PI) based Polymer and blending photopolymer surfaces were studied. High pretilt angle of the NLC can be measured by obliquely polarized UV exposure on a photo-crosslinkable polyimide based polymer surface containing biphenyl (BP), decal (de), and cholesterol (chol) group, respectively. However, the low pretilt angle of the NLC was measured by obliquely polarized UV exposure on the blending photopolymer (PI and cinnamate materials) surfaces. Consequently, the pretilt angle of the NLC generated on the photo-crosslinkable polyimide based polymer surfaces using the in-situ photodimerization method was higher than that of the blending photopolymers.

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