• 수산해양기술연구
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• 제51권4호
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• pp.561-566
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• 2015

In this study, the effect of temperature effect of the rubber matrix filled with nano sized silica particles composites with silica volume fraction of 19-25% was investigated by the Charpy impact test. The Charpy impact test was conducted in the temperature range from $-40^{\circ}C$ to $0^{\circ}C$. The critical energy release rate GIC of the rubber matrix composites filled with nano sized silica particles was considerably affected by temperature and it was shown that the maximum value was appeared at higher temperature between temperature tested and it was shown that the value of GIC increases as temperature tested increases. The major fracture mechanisms were matrix deformation, silica particle debonding and delamination, microcrack between particles and matrix, and/or pull out between particles and matrix which is ascertained by SEM photographs of Charpy impact surfaces fracture.

• International Journal of Advanced Culture Technology
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• 제3권1호
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• pp.13-20
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• 2015

The self-cleaning properties of nano-zinc oxide on cotton fabrics have been investigated. The cotton fabric has been prepared by pad-dry method. The nano-zinc oxide was encapsulated in the polystyrene particle by mini-emulsion process prior used. The loading amount of zinc oxide particles into the mini-emulsion were various from 1% wt to 40%wt. The particles sizes of ZnO-encapsulated polystyrene mini-emulsion were determined using dynamic light scattering. It was showed that the particle size of the mini-emulsion was in the range of 124-205 nm. The topography and morphology of ZnO-encapsulated polystyrene which coated on cotton fabrics was observed using scanning electron microscopy. The crystal structure of ZnO-coated on cotton fabrics was explored by X-ray diffraction spectroscopy. The photocatalytic activities of zinc oxide were present through the self-cleaning properties. The presents of the zinc oxide on cotton fabrics significantly showed the improving of the self-cleaning properties under UV radiation.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 광주전남지부
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• pp.39-42
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• 2006

Titania sols or powders were are very promising materials for environment as photocatalyst. The band gap energy of $TiO_2$ has been known to be 2.8 to 3.2 eV. But the measuring system of its band gap is usually depend on absorption properties. Thus, in this study, absorption properties of $TiO_2$ sols prepared by hydrothermal process were researched with the effect of various particle sizes and concentrations. The mean particle size in $TiO_2$ sols increased as 15 nm to 60 nm, absorption graph measured by UV-Vis spectrometer shows to move red-shift. When dilute solution added with $2^n$ in $TiO_2$, the band gap energy increases as linear function.

• 한국전기전자재료학회논문지
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• 제36권2호
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• pp.164-169
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• 2023

Nano Pt particles were dispersed on carbon-based supports by a polyol process for a catalyst application in a polymer electrolyte fuel cell. We tried to optimize the effect of pH on the electrostatic forces between the support and the Pt colloids. We investigated the relationship among the surface charges on the carbon support, the solution pH, and the concentration of a glycolate, and the Pt particle size. The produced catalyst with nano Pt particles on the support was evaluated by the long-term cyclic voltammetry (CV) performance test and compared with the results from a commercial catalyst. Our experimental results reveal that the pH-control can modify the particle size distribution and the dispersion of the nano Pt particles. This resulted in a cost-effective method for the synthesis of highly Pt loaded Pt/C catalysts for fuel cells better than a commercial catalyst system.

• Journal of Pharmaceutical Investigation
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• 제38권2호
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• pp.99-104
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• 2008

PLGA micro/nano particles encapsulating ranitidine as a hydrophilic model drug were prepared by the double-emulsion solvent evaporation method. Surface morphology investigation by scanning electron microscope (SEM) showed that the emulsification by sonication could produce nanoparticles, whereas microparticles were prepared using high speed homogenizer. Moreover, while nanohalf-shell structure instead of spherical nanoparticle could be produced by adding poloxamer into oil phase (MC) with PLGA 504H, the addition of poloxamer didn't change particle shape in case of PLGA 502H. On the other hand, microparticle with poloxamer had more surface pores than those without poloxamer. The size and polydispersity (PDI) of particles were determined by particle size analyzer. Effective diameters of particles were in the range of $400{\sim}800\;nm$ and $1200{\sim}3300\;nm$ in case of nanoparticles and microparticles, respectively. Encapsulation efficiencies were in the range of $1.2{\sim}2.9%$. The addition of poloxamer produced the particles with higher encapsulation efficiency. In vitro release study in phosphate buffer (pH 7.4) at $37^{\circ}C$ showed common large initial burst release. However, the relative slower release profile could be observed in case of microparticles. Poloxamer addition increased the release rate, which was thought to be related to the increased surface area of particles.

• 자원리싸이클링
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• 제16권1호
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• pp.28-36
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• 2007

폐 ITO 타겟을 염산에 용해시킨 복합 산용액을 원료로 하여 자체기술에 의해 개발한 분무열분해 반응장치를 통하여 평균입도가 50nm이하인 나노 ITO 분말을 제조하였으며, 반응온도 및 원료용액의 농도 등의 반응인자들의 변화에 따른 ITO 분말의 특성을 파악하였다. 반응온도가 $800^{\circ}C$로부터 $1100^{\circ}C$로 변화함에 따라 생성된 ITO 분말의 평균 입도는 40nm로부터 100nm정도까지 증가하고 있었으며, 조직도 점점 치밀화되면서 각각의 입자들이 독립된 다각형 형태를 나타내었으며, 입도분포는 더욱 불균일하게 나타나고 있었다. 또한 반응온도 증가에 따라 XRD 피크의 강도는 증가하였으며 비표면적은 감소하고 있었다. 원료용액 내의 인듐 성분의 농도가 50g/l로부터 400g/l로 증가됨에 따라 생성된 ITO 분말의 평균입도는 점점 증가하는 반면 입도분포는 더욱 불균일 하였다. 농도가 50g/l인 경우에는 ITO 분말의 평균입도는 30nm 이하이면서 입도분포는 비교적 균일하게 나타나고 있었다. 반면 농도가 포화농도에 가까운 400g/l인 경우에는 분말들의 입도분포는 20nm 정도부터 100nm 이상까지 공존하는 매우 불균일한 형태를 나타내고 있었다. 농도가 증가함에 따라 XRD 피크의 강도는 점점 증가하였으며 비표면적은 점점 감소하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.595-596
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• 2012

• 한국분말재료학회지
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• 제8권3호
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• pp.192-196
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• 2001

Ag doped Hydroxyapatite powder in nano-scale was successfully synthesized either by co-precipitation or by ion exchange route. The fabricated powder was successfully dispersed through freeze drying due to the prevention of secondary particles. The antimicrobial effects of nano-HAp against E.coli was superior to micron ones not only in its strength but also in duration.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.413-414
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• 2006

The effects of several experimental parameters on the formation of stable Ni nanoparticles dispersion were investigated. The suspensions of Ni nanoparticles were produced in organic solvents using Hypermer KD-2 as a dispersant. The transmission profiles, particle size distribution, zeta potential, and visual inspection results were used to discuss the stability of the dispersion. The optimal conditions for the formation of stable dispersion are evaluated.

• 한국고분자학회지:고분자과학과기술
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• 제17권3호
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• pp.303-311
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• 2006