• Title/Summary/Keyword: 슬러리코팅

Search Result 51, Processing Time 0.023 seconds

Characteristics of Meta-aramid Fabrics Coated with Slurry of Nanoscale SiC Particles (나노 탄화규소(SiC) 슬러리로 코팅된 메타-아라미드 직물의 특성)

  • Park, Jong Hyeon;Lee, Sun Young;Won, Jong Sung;Lee, Eung Bo;Kim, Eui Hwa;Lee, Seung Goo
    • Textile Coloration and Finishing
    • /
    • v.29 no.3
    • /
    • pp.131-138
    • /
    • 2017
  • Most of high performance fabrics for the car racing protective clothing have been developed to have thermal resistance, flame retardant property, impact resistance and anti-frictional properties to protect the racer from the crucial accident. In this study, the meta-aramid fabric, which has inherent flame retardant, was coated with nanoparticles of SiC to enhance the impact resistance and anti-friction properties. Uniform coating of the nanoparticles onto the fabrics was obtained by using tape casting method. As the experimental parameters, size and content of the SiC nanoparticle were varied with the coating conditions of the fabric surface. The effects of the nanoparticle coating on the properties of meta-aramid fabric were examined with various instrumental analyses such as SEM, tensile strength and abrasion test.

Fabrication of Gas Diffusion Layer for Fuel Cells Using Heat treatment Slurry Coating Method (열처리 슬러리코팅법을 이용한 연료전지 가스확산층의 제조)

  • Kim, Sungjin;Park, Sung Bum;Park, Yong-Il
    • Journal of the Korean Society for Heat Treatment
    • /
    • v.25 no.2
    • /
    • pp.65-73
    • /
    • 2012
  • The Gas Diffusion Layer (GDL) of fuel cell, are required to provide both delivery of reactant gases to the catalyst layer and removal of water in either vapor or liquid form in typical PEMFCs. In this study, the fabrication of GDL containing Micro Porous Layer (MPL) made of the slurry of PVDF mixed with carbon black is investigated in detail. Physical properties of GDL containing MPL, such as electrical resistance, gas permeability and microstructure were examined, and the performance of the cell using developed GDL with MPL was evaluated. The results show that MPL with PVDF binder demonstrated uniformly distributed microstructure without large cracks and pores, which resulted in better electrical conductivity. The fuel cell performance test demonstrates that the developed GDL with MPL has a great potential due to enhanced mass transport property due to its porous structure and small pore size.

Optimization for Ammonia Decomposition over Ruthenium Alumina Catalyst Coated on Metallic Monolith Using Response Surface Methodology (반응표면분석법을 이용한 루테늄 알루미나 메탈모노리스 코팅촉매의 암모니아 분해 최적화)

  • Choi, Jae Hyung;Lee, Sung-Chan;Lee, Junhyeok;Kim, Gyeong-Min;Lim, Dong-Ha
    • Clean Technology
    • /
    • v.28 no.3
    • /
    • pp.218-226
    • /
    • 2022
  • As a result of the recent social transformation towards a hydrogen economy and carbon-neutrality, the demands for hydrogen energy have been increasing rapidly worldwide. As such, eco-friendly hydrogen production technologies that do not produce carbon dioxide (CO2) emissions are being focused on. Among them, ammonia (NH3) is an economical hydrogen carrier that can easily produce hydrogen (H2). In this study, Ru/Al2O3 catalyst coated onmetallic monolith for hydrogen production from ammonia was prepared by a dip-coating method using a catalyst slurry mixture composed of Ru/Al2O3 catalyst, inorganic binder (alumina sol) and organic binder (methyl cellulose). At the optimized 1:1:0.1 weight ratio of catalyst/inorganic binder/organic binder, the amount of catalyst coated on the metallic monolith after one cycle coating was about 61.6 g L-1. The uniform thickness (about 42 ㎛) and crystal structure of the catalyst coated on the metallic monolith surface were confirmed through scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Also, a numerical optimization regression equation for NH3 conversion according to the independent variables of reaction temperature (400-600 ℃) and gas hourly space velocity (1,000-5,000 h-1) was calculated by response surface methodology (RSM). This model indicated a determination coefficient (R2) of 0.991 and had statistically significant predictors. This regression model could contribute to the commercial process design of hydrogen production by ammonia decomposition.

Optimization of anode and electrolyte microstructure for Solid Oxide Fuel Cells (고체산화물 연료전지 연료극 및 전해질 미세구조 최적화)

  • Noh, Jong Hyeok;Myung, Jae-ha
    • Korean Chemical Engineering Research
    • /
    • v.57 no.4
    • /
    • pp.525-530
    • /
    • 2019
  • The performance and stability of solid oxide fuel cells (SOFCs) depend on the microstructure of the electrode and electrolyte. In anode, porosity and pore distribution affect the active site and fuel gas transfer. In an electrolyte, density and thickness determine the ohmic resistance. To optimizing these conditions, using costly method cannot be a suitable research plan for aiming at commercialization. To solve these drawbacks, we made high performance unit cells with low cost and highly efficient ceramic processes. We selected the NiO-YSZ cermet that is a commercial anode material and used facile methods like die pressing and dip coating process. The porosity of anode was controlled by the amount of carbon black (CB) pore former from 10 wt% to 20 wt% and final sintering temperature from $1350^{\circ}C$ to $1450^{\circ}C$. To achieve a dense thin film electrolyte, the thickness and microstructure of electrolyte were controlled by changing the YSZ loading (vol%) of the slurry from 1 vol% to 5 vol. From results, we achieved the 40% porosity that is well known as an optimum value in Ni-YSZ anode, by adding 15wt% of CB and sintering at $1350^{\circ}C$. YSZ electrolyte thickness was controllable from $2{\mu}m$ to $28{\mu}m$ and dense microstructure is formed at 3vol% of YSZ loading via dip coating process. Finally, a unit cell composed of Ni-YSZ anode with 40% porosity, YSZ electrolyte with a $22{\mu}m$ thickness and LSM-YSZ cathode had a maximum power density of $1.426Wcm^{-2}$ at $800^{\circ}C$.

Fabrication of Electrolyte for Direct Carbon Fuel Cell and Evaluation of Properties of Direct Carbon Fuel Cell (직접탄소 연료전지용 전해질 제조 및 직접탄소 연료전지 특성 평가)

  • Pi, Seuk-Hoon;Cho, Min-Je;Lee, Jong-Won;Lee, Seung-Bok;Lim, Tak-Hyoung;Park, Seok-Joo;Song, Rak-Hyun;Shin, Dong-Ryul
    • Korean Chemical Engineering Research
    • /
    • v.49 no.6
    • /
    • pp.786-789
    • /
    • 2011
  • In order to estimate the possibility of applying electrolytes generally used in solid oxide fuel cells(SOFCs) to direct carbon fuel cells(DCFCs), properties of YSZ(yttria stabilized zirconia) electrolyte were evaluated. In this study, vacuum slurry coating method was adapted to coat thin layer on anode support substrate. After sintering the electrolyte at $1400^{\circ}C$ for 5hrs, microstructure was analyzed by using SEM image. Also, gas permeability and ionic conductivity were measured to find out the potential possibility of electrolyte for DCFCs. The YSZ electrolyte represented dense coating layer and low gas permeability value. The ionic conductivity of YSZ electrolyte was high over $800^{\circ}C$. After measurement of the electrolyte properties, direct carbon fuel cell was fabricated and its performance was measured at $800^{\circ}C$.

Effect of Concentration and Surface Property of Silica Sol on the Determination of Particle Size and Electrophoretic Mobility by Light Scattering Method (광산란법에서 실리카 졸의 농도 및 표면특성이 입자 크기 및 전기영동 이동도 측정결과에 미치는 영향)

  • Cho, Gyeong Sook;Lee, Dong-Hyun;Kim, Dae Sung;Lim, Hyung Mi;Kim, Chong Youp;Lee, Seung-Ho
    • Korean Chemical Engineering Research
    • /
    • v.51 no.5
    • /
    • pp.622-627
    • /
    • 2013
  • Colloidal silica is used in various industrial products such as chemical mechanical polishing slurry for planarization of silicon and sapphire wafer, organic-inorganic hybrid coatings, binder of investment casting, etc. An accurate determination of particle size and dispersion stability of silica sol is demanded because it has a strong influence on surface of wafer, film of coatings or bulks having mechanical, chemical and optical properties. The study herein is discussed on the effect of measurement results of average particle size, sol viscosity and electrophoretic mobility of particle according to the volume fraction of eight types of silica sol with different size and surface properties of silica particles which are presented by the manufacturer. The measured particle size and the mobility of these sol were changed by volume fraction or particle size due to highly active surface of silica particle and change of concentration of counter ion by dilution of silica sol. While in case the measured sizes of small particles less than 60 nm are increased with increasing volume fraction, the measured sizes of larger particles than 60 nm are slightly decreased. The mobility of small particle such as 12 nm are decreased with increase of viscosity. However, the mobility of 100 nm particles under 0.048 volume fraction are increased with increasing volume fraction and then decreased over higher volume fraction.

The Effect of Fe and Fe2O3 Powder Mixing Ratios on the Pore Properties of Fe Foam Fabricated by a Slurry Coating Process (슬러리 코팅 공정으로 제조된 Fe 폼의 기공 특성에 미치는 Fe 및 Fe2O3 분말의 혼합 비율의 영향)

  • Choi, Jin Ho;Jeong, Eun-Mi;Park, Dahee;Yang, Sangsun;Hahn, Yoo-Dong;Yun, Jung-Yeul
    • Journal of Powder Materials
    • /
    • v.21 no.4
    • /
    • pp.266-270
    • /
    • 2014
  • Metal foams have a cellular structure consisting of a solid metal containing a large volume fraction of pores. In particular, open, penetrating pores are necessary for industrial applications such as in high temperature filters and as a support for catalysts. In this study, Fe foam with above 90% porosity and 2 millimeter pore size was successfully fabricated by a slurry coating process and the pore properties were characterized. The Fe and $Fe_2O_3$ powder mixing ratios were controlled to produce Fe foams with different pore size and porosity. First, the slurry was prepared by uniform mixing with powders, distilled water and polyvinyl alcohol(PVA). After slurry coating on the polyurethane(PU) foam, the sample was dried at $80^{\circ}C$. The PVA and PU foams were then removed by heating at $700^{\circ}C$ for 3 hours. The debinded samples were subsequently sintered at $1250^{\circ}C$ with a holding time of 3 hours under hydrogen atmosphere. The three dimensional geometries of the obtained Fe foams with an open cell structure were investigated using X-ray micro CT(computed tomography) as well as the pore morphology, size and phase. The coated amount of slurry on the PU foam were increased with $Fe_2O_3$ mixing powder ratio but the shrinkage and porosity of Fe foams were decreased with $Fe_2O_3$ mixing powder ratio.

A Study on the Application of Aluminosilicate Sols in Shell Mold for Investment Casting ( I ) (정밀주조용 쉘 몰드에 알루미노실리케이트계 졸의 응용에 관한 연구 ( I ))

  • Kim, Jae-Won;Kim, Du-Hyeon;Seo, Seong-Mun;Jo, Chang-Yong;Choe, Seung-Ju;Kim, Jae-Cheol;Park, Yeong-Gyu
    • Korean Journal of Materials Research
    • /
    • v.9 no.12
    • /
    • pp.1188-1195
    • /
    • 1999
  • The effect of aluminosilicate sol on the formation of mullite layer in zircon shell mold was investigated. Aluminosilicate sol was prepared by mixing of colloidal silica(NALCO(R) 1130) and an aqueous solution of aluminium nitrate at room temperature. The sol gelled at 50$^{\circ}C$ for 48 hrs. It was identified that the gel consists of aluminosilicate complexes and gibbsite. The coordination number of all aluminium ion bonded with silicon ion was four. Mullite phase formed by sintering above 1300$^{\circ}C$. XRD peak of mullite sharpened with increasing sintering temperature and the content of aluminium nitrate. Mullite phase displayed whisker-like 0.5~5${\mu}m $ particles. Separation between 1st and 3rd layers during sintering and the difference in thermal expansion coefficient between residual silica and mullite.

  • PDF

Continuous Coating Process Development for PEFC Membrane Electrode Assembly (고분자 연료전지용 MEA 연속 코팅공정 개발)

  • Park, Seok-Hee;Yoon, Young-Gi;Kim, Chang-Soo;Lee, Won-Yong
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2006.06a
    • /
    • pp.110-112
    • /
    • 2006
  • Membrane electrode assembly (MEA) for polymer electrolyte fuel cell (PEFC) are commonly prepared in the research laboratory by spraying, screen-printing and brushing catalyst slurry onto membrane or other support material like carbon paper or polyimide film in a batch style. These hand applications of the catalyst slurry are painstaking process with respect to precision of catalyst loading and reproducibility. It has been generally mentioned that the adoption of continuous process is very helpful to develop the reliable product. In the present work, we report the results of using continuous type coater with doctor-blade to coat catalyst slurry for preparing the MEA catalyst layers In a faster and highly reproducible fashion. We show that while expectedly faster than batch style, the machine coater requires the use of slurry of appropriate composition and a properly selected transfer decal material in order to achieve superior MEA plat lnw loading reproducibility. To make highly viscous catalyst slurry that is imperative for using coater, we use 40wt.% Nafion solution and minimize the content of organic solvent. And the choice of proper high surface area catalyst is important in the viewpoint of making well-dispersed slurry. After catalyst coating onto the support material, we transferred the catalyst layer to both sides of Nafion membrane by hot-pressing In this case, the degree of transfer was Influenced by hot-pressing condition including temperature, pressure, and time. To compare the transferring ability, we compared so many films and detaching papers. And among the support, polyethylene terephthalate(PET) film shows the prominent result.

  • PDF

Study on The Effect of Electrode Drying Temperature on The Silicon Electrode Characteristics of Lithium Secondary Batteries (전극 건조 온도가 리튬이차전지의 실리콘 전극 특성에 미치는 영향 연구)

  • Dong-Wan Ham;Myeong-Hui Jeong;Jeong-Tae Kim;Beom-Hui Lee;Hyeon-Mo Moon;Sun-Yul Ryou
    • Journal of the Korean Electrochemical Society
    • /
    • v.27 no.3
    • /
    • pp.97-104
    • /
    • 2024
  • The electrodes of commercialized lithium secondary batteries are manufactured through a wet coating process, and the drying process (DC) is a very important factor as to electrode production speed and process cost. In this study, silicon anodes were manufactured under high-temperature (180 ℃) and low-temperature (50 ℃) DC to investigate the quality and the electrochemical performance of Si-electrodes according to DC. High-temperature DC can quickly evaporate the solvent in the Si-electrode slurry, improving the electrode production rate. However, this also causes the electrode composite to peel off from the current collector. As a result, the Si-electrode's adhesion weakened, and the electrode coating's quality deteriorated. In addition, the Si-electrode manufactured under high-temperature was found to have a thicker composite material than the Si-electrode manufactured under low-temperature. Si-electrodes manufactured under high-temperature had higher sheet resistance and lower electrical conductivity than those manufactured under low-temperature. Consequently, the Si-electrode manufactured under low-temperature showed 152.5% superior cycle performance compared to the Si-electrode manufactured under high-temperature. (Discharge capacities of Si-electrodes manufactured under high-temperature and low-temperature DC were 844 and 1287 mAh g-1, respectively, after 300 cycles). Establishing the DC of Si-electrodes can easily provide new perspectives to improve the quality and stability of Si-electrodes.