• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.138.2-138.2
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• 2010

Scandium-doped zirconium, ScSZ-based electrolyte, provides higher oxygen conductivity than YSZ and nano-based electrolyte materials are ideal for fabricating thin film electrolyte membrane of SOFC unit cell. Moreover, it may be applied to anode and cathode as well as electrolyte as ionic conductor. In this report, nano-based ScSZ-based electrolyte powder was prepared by co-precipitation synthesis. The particle size, surface area and morphology of the powder were observed by SEM and BET. Thin film electrolyte of under $10{\mu}m$ was fabricated by tape casting and co-firing using the synthesized ScSZ-based powders, and ionic conductivity and gas permeability of electrolyte film were evaluated. Finally, the SOFC unit cell was fabricated using the anode-supported electrolyte prepared by a tape casting method and co-sintering. Electrochemical evaluations of the SOFC unit cell, including measurements such as power density and impedance, were performed and analyzed.

• Journal of Sensor Science and Technology
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• v.29 no.5
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• pp.332-335
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• 2020

Drop casting, a solution process, is a simple low-cost fabrication technique that does not waste material. In this study, we elucidate the effect of the concentration of a InGaZnO solution on the electrical properties of drop-cast oxide thin-film transistors. The higher the concentration the larger the amount of remnant InGaZnO solutes, which yields a thicker thin film. Accordingly, the electrical properties were strongly dependent on the concentration. At a high concentration of 0.3 M (or higher), a large current flowed but did not lead to switching characteristics. At a concentration lower than 0.01 M, switching characteristics were observed, but the mobility was small. In addition to a high mobility, sufficient switching characteristics were obtained at a concentration of 0.1 M owing to the appropriate thickness of the semiconductor layer. This study provides a technical basis for the low-cost fabrication of switching devices capable of driving a sensor array.

• Journal of Powder Materials
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• v.22 no.6
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• pp.438-442
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• 2015

Porous thick film of alumina which is fabricated by freeze tape casting using a camphene-camphor-acrylate vehicle. Alumina slurry is mixed above the melting point of the camphene-camphor solvent. Upon cooling, the camphene-camphor crystallizes from the solution as particle-free dendrites, with the $Al_2O_3$ powder and acrylate liquid in the interdendritic spaces. Subsequently, the acrylate liquid is solidified by photopolymerization to offer mechanical properties for handling. The microstructure of the porous alumina film is characterized for systems with different cooling rate around the melting temperature of camphor-camphene. The structure of the dendritic porosity is compared as a function of ratio of camphene-camphor solvent and acrylate content, and $Al_2O_3$ powder volume fraction in acrylate in terms of the dendrite arm width.

• The Korean Journal of Ceramics
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• v.7 no.1
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• pp.16-19
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• 2001

For the fast dry of the aqueous tape, the process which water was reaplaced by organic solvent was proposed. Socalled, it was the solvent washing dry. Three organic solvents (methanol, ethanol and acetone) were selected for the washing solvent. The weight loss of the washed tapes was measured to evaluate the dry rate of the tapes and dried tapes were examined the generation of the cracks with the variations of the organic solvent and the washing time. Methanol, ethanol and acetone were available organic solvents for this method. The tapes washed in methanol, ethanol and acetone were dried rapidly for twenty minutes. After thirty minutes, the weight losses were not found any more, The solvent of the lower surface tension can decreases the crack of dried tape. If solvent substitutes water completely, though it was fast dried, crack can be eliminated.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.5
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• pp.318-324
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• 2017

Powder compaction technology is widely used to prepare thermal battery components. This method, however, is limited by the size, thickness, and geometry of the battery components. This limitation leads to excessive cell capacity, overweight, and higher cost of the pellets, which decreases the specific capacities and delays the activation time of thermal batteries. $FeS_2$ thin-film cathodes were fabricated by tape-casting technology and analyzed by SEM and EDS in this paper. The residual organic binder of the $FeS_2$ thin-film cathodes decreased with the temperature of the heat treatment, which improved the specific capacity because of the lower resistance. Specific capacities of the $FeS_2$ thin-film cathodes decreased because of the higher residual binder and the restrictive reaction of active materials with molten salts as the thickness increased. $FeS_2$ thin-film cathodes showed much higher specific capacity (1,212.2 As/g) than pellet cathodes (860.7 As/g) at the optimal heat-treatment temperature ($230^{\circ}C$).

• The Korean Journal of Ceramics
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• v.7 no.2
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• pp.55-57
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• 2001

For the fast dry of the aqueous tape, the process which water was replaced by organic solvent was proposed. Socalled, it was the solvent washing dry. Three organic solvents (methanol, ethanol and acetone) were selected for the washing solvent. The weight loss of the washed tapes was measured to evaluate the dry rate of the tapes and dried tapes were examined the generation of the cracks with the variations of the organic solvent and the washing time. Methanol, ethanol and acetone were available organic solvents for this method. The tapes washed in methanol, ethanol and acetone were dried rapidly for twenty minutes. After thirty minutes, the weight losses were not found any more. The solvent of the lower surface tension can decreases the crack of dried tape. If solvent substitutes water completely, though it was fast dried, crack can be eliminated.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.24-24
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• 2018

One of the challenges in tissue engineering is the design of optimal biomedical scaffolds, which can be governed by topographical surface characteristics, such as size, shape, and direction. Of these properties, we focus on the effects of nano - to micro - sized hierarchical surface. To fabricate the hierarchical surface structure on poly(${\varepsilon}$-caprolactone) (PCL) film, we employed a nano/micro-casting technique (NCT) and modified plasma process. The micro size topography of PCL film was controlled by sizes of the micro structures on lotus leaf. Also, the nano-size topography and hydrophilicity of PCL film were controlled by modified plasma process. After the plasma treatment, the hydrophobic property of the PCL film was significantly changed into hydrophilic property, and the nano-sized structure was well developed, as increasing the plasma exposure time and applied power. The surface properties of the modified PCL film were investigated in terms of initial cell morphology, attachment, and proliferation using osteoblast-like-cells (MG63). In particular, initial cell attachment, proliferation and osteogenic differentiation in the hierarchical structure were enhanced dramatically compared to those of the smooth surface.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.04a
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• pp.26-27
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• 1995

Most of synthetic polymeric membranes used in ultrafiltration, reverse osmosis and microfiltration processes are prepared by phase inversion(or phase separation) technique. In this technique, a homogeneous polymer solution is cast into thin film or hollow fiber shape and then immersed into a nonsolvent coagulant bath. The exchange of solvent and nonsolvent across the interface between casting solution and coagu!ant can make the casting solution phase-separate and form a membrane with a symmetric or asymmetric structure. Because of importance of this technique in membrane field, many investigations have been dedicated to elucidate the mechanism of membrane formation by phase inversion technique.[1-10] These investigation have suggested that the structure formation and permeation properties of phase inversion membrane depend on the variables such as the nature and content of casting solution and coagulant, temperature of casting solution and coagulant, and the diffusional exchange rate of solvent and nonsolvent etc. which can be related to the thermodynamic and kinetic properties of the casting system. The variables such as the nature and content of casting solution can also be the important factor affecting the structure formation and permeation property of the phase inversion membrane.

• Proceedings of the Korean Society of Rheology Conference
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• 2002.05a
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• pp.73-76
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• 2002

• Proceedings of the Korean Fiber Society Conference
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• 1995.10a
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• pp.114-115
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• 1995