• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2015년도 추계학술대회 논문집
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• pp.303-303
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• 2015

In order to investigate ion release and biocompatibility of Ti-6Al-4V dental alloy by electrochemical corrosion test and MTT assay, commercial Ti-6Al-4V alloy rod (99.99% Ti, USA, Co) were used in the study. The microstructure of the alloys was examined by optical microscopy (OM), Field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), MTT assay, and corrosion test. From the polarization curves, very low current densities were obtained for Ti-6Al-4V alloys, indicating a formation of stable passive layer.

• Macromolecular Research
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• 제14권1호
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• pp.59-65
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• 2006

We report a new approach to fabricate electrospun polymer nonwoven mats with porous surface morphology by varying the collector temperature during electrospinning. Polymers such as poly(L-lactide) (PLLA), polystyrene (PS), and poly(vinyl acetate) (PVAc) were dissolved in volatile solvents, namely methylene chloride (Me) and tetrahydrofuran (THF), and subjected to electrospinning. The temperature of the collector in the electrospinning device was varied by a heating system. The resulting nonwoven mats were characterized by using scanning electron microscopy (SEM), field emission SEM (FESEM), and atomic force microscopy (AFM). We observed that the surface morphology, porous structure, and the properties such as pore size, depth, shape, and distribution of the nonwoven mats were greatly influenced by the collector temperature.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2015년도 춘계학술대회 논문집
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• pp.107-107
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• 2015

In order to investigate electrochemical behavior and biocompatibility of Co-Cr dental alloy by electrochemical corrosion test and MTT assay, the xCo-25Cr-yW-zNi alloys were used in this study. Samples of Co-Cr-W-Ni alloys were manufactured using arc melting furnace. The microstructure of the alloys was examined by optical microscopy (OM), Field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), MTT assay, and corrosion test. Corrosion resistance increased slightly as cobalt (Co) content increased. And bioactivity was concerned with nickel (Ni) and tungsten (W). Biocompatibility of Co-Cr alloy depended on Ni and W contents.

• 한국표면공학회지
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• 제55권2호
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• pp.77-83
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• 2022

Nanocrystalline MoN coatings were prepared by inductively coupled plasma magnetron sputtering (ICPMS) changing the plasma power from 0 W to 200 W. The properties of the coatings were analyzed by x-ray diffraction, field emission scanning electron microscopy, atomic force microscopy, nanoindentation tester and semiconductor characterization system. As the ICP power increases, the crystal structure of the MoN coatings changed from a mixed phase of γ-Mo₂N and α-Mo to a single phase γ-Mo₂N. MoN coatings deposited by ICPMS at 200 W showed the most compact microstructure with the highest nanoindentation hardness of 27.1 GPa. The electrical resistivity of the coatings decreased from 691.6 μΩ cm to 325.9 μΩ cm as the ICP power increased.

• 마이크로전자및패키징학회지
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• 제26권1호
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• pp.23-28
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• 2019

타이타니아 ($TiO_2$)는 독성이 없고 매우 높은 굴절률, 촉매 활성 및 생체 적합성을 지니고 있으며 화학적 안정성이 있고 높은 이방성을 갖는 저렴한 재료로써 다양한 분야에서 각광받고 있는 세라믹 소재이다. 이러한 $TiO_2$를 sol-gel법을 이용하여 나노입자화 하였다. 나노입자 형성중에 pH를 조절하여 $TiO_2$의 결정성을 제어하였다. 합성된 나노입자는 엑스선 회절분석법, 퓨리에 분광기(Fourier transform infrared), 전계방사형 주사전자현미경(field emission scanning electron microscopy)과 포토루미네선스(photoluminescence spectroscopy)를 이용하여 분석하였다. 합성된 $TiO_2$ 나노입자는 5 nm 이하의 크기를 갖는 것을 확인하였다. 나노입자의 결정성이 증가됨에 따라 550 nm 영역의 발광세기가 증가함을 확인하였다. 이러한 결과로 $TiO_2$ 나노입자의 결정성 조절을 통한 발광 특성 조절을 기대할 수 있다.

• 한국염색가공학회지
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• 제23권2호
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• pp.107-117
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• 2011

Polyurethane (PU) was synthesized by one-shot process and the PU nanofiber was prepared by electrospinning. In this study, electrospun PU multi-membranes were prepared with various coating thickness ratio of base resin to top resin, where the base resin contains melamine curing agent and acid catalyst and the top resin contains water-repellent agent of fluoro-carbon compounds. The PU nanofiber multi-membranes were analyzed by field-emission scanning electron microscopy, differential scanning calorimeter, breathability, tensile strenth, air permeability and water resistance. The results showed that the PU multi-membrane provided excellent waterproof and moisture permeability.

• 반도체디스플레이기술학회지
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• 제18권2호
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• pp.53-57
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• 2019

In this study, we prepared sputtering cathode for large sputtering thin film in the facing targets sputtering(FTS) system. Before fabrication of cathode equipment, we investigated optimal magnetic flux in the sputtering cathode by using magnetic field stimulation(Comsol). According to the result of magnetic field stimulation, we manufactured the cathode. After we mounted laboratory-designed cathode on FTS system, the discharge properties were observed in vacuum condition. In addition, ITO films were deposited on glass substrate and their electrical and optical properties were investigated by various measurements (four-point probe, UV-VIS spectrometer, field emission scanning electron microscopy(FE-SEM), Hall-effect measurement).

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.692-693
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• 2002

Well-aligned multi-wall carbon nanotubes (MWNTs) were fabricated by utilizing a radio frequency plasma-enhanced chemical vapor deposition (rf-PECVD) system from Ni particles at the bottom of anodic alumina nanoholes (AAN). To remove the amorphous graphite layers on the AAN surface and to eliminate the protrusion of MWNT tips, the AAN surface with MWNTs were treated by external rf plasma source. As a result, the AAN surface almost became flat without having any protrusion of MWNT tips. The diameter, length of MWNTs and AAN were investigated by using a scanning electron microscopy (SEM). Raman spectroscopy was also used to characterize wall structure of the carbon nanotube. And the emission properties of the MWNTs were measured for the application of field emission display (FED) in near future.

• 한국분말재료학회지
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• 제11권4호
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• pp.328-332
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• 2004

Fe nanopowders were successfully synthesized by plasma arc discharge (PAD) process using Fe rod. The influence of chamber pressure on the microstructure was investigated by means of X-ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM), Transmission Electron Microscopy (TEM) and X-ray Photoelectron Spectroscopy (XPS). The prepared particles had nearly spherical shapes and consisted of metallic cores (a-Fe) and oxide shells (Fe$_{3}$O$_{4}$), The powder size increased with increasing chamber pressure due to the higher dissolution and ejection rate of H$_2$ and gas density in the molten metal.

• Carbon letters
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• 제13권2호
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• pp.88-93
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• 2012

Polypyrrole (PPy)/multi-walled carbon nanotubes (MWCNTs) composites were prepared by in situ polymerization of pyrrole on the surface of MWCNTs templates to improve the ammonia gas sensing properties. PPy morphologies, formed on the surface of MWCNTs, were investigated by field emission scanning electron microscopy. The thermal stabilities of the PPy/MWCNTs composites were improved as the content of MWCNTs increased due to the higher thermal stability of the MWCNTs. PPy/MWCNTs composites showed synergistic effects in improving the ammonia gas sensing properties, attributed to the combination of efficient electron transfer between PPy/MWCNTs composites and ammonia gas, and the reproducible electrical resistance variation on PPy during the gas sensing process.