• YAKHAK HOEJI
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• v.40 no.6
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• pp.646-652
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• 1996

Epidermal Growth Factor (EGF), discovered by Stanley Cohen in 1960, has a potential healing effect for wounds and bums. Considering wound care, in order to avoid physical stress at the wound surface and efficiently apply EGF, the need for viscous spraying solutions was essential. Viscous spraying solutions containing EGF were prepared by utilizing viscosity-building polymer, poloxamer 407, and by introducing liposome systems. On the other hand, EGF is purified on reverse HPLC gradient program with the mobile solvent of acetonitrile. It is necessary to observe liposomal EGF changes as the acetonitrile contents varied in order to introduce liposome systems at the step of EGF solution (at the time of EGF purifying). By evaluating the size distribution and entrapment efficiency of EGF liposome, it was possible to detemine the limit contents of acetonitrile and establish the optimal conditions for solution formulations. It has been revealed that, as the acetonitrile content increases, mean diameter of EGF liposomes increased and the width of size distribution tends to decrease. The limit contents of acetonitrile were 10%, since there was little difference to the acetonitrile free liposomes.

• Journal of Powder Materials
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• v.30 no.5
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• pp.424-430
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• 2023

YAG phosphor powders were fabricated by the atmospheric plasma spraying method with the spray-dried spherical YAG precursor. The YAG precursor slurry for the spray drying process was prepared by the PVA solution chemical processing utilizing a domestic easy-sintered aluminum oxide (Al₂O₃) powder as a seed. The homogenous and viscous slurry resulted in dense granules, not hollow or porous particles. The synthesized phosphor powders demonstrated a stable YAG phase, and excellent fluorescence properties of approximately 115% compared with commercial YAG:Ce³⁺ powder. The microstructure of the phosphor powder had a perfect spherical shape and an average particle size of approx imately 30 ㎛. As a result of the PKG test of the YAG phosphor powder, the synthesized phosphor powders exhibited an outstanding luminous intensity, and a peak wavelength was observed at 531 nm.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.110-112
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• 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.