• Journal of Korean Society of Environmental Engineers
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• v.39 no.7
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• pp.418-425
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• 2017

ZnO nanoparticles (ZnO NPs) are mainly used in semiconductors, solar cells, biosensors, and cosmetics (sunscreen). In this study, we investigated the behavior of ZnO NPs in aquatic and soil environments and their effects on plants (Artemisia annua L.) in hydroponic cultivation. It was confirmed that the ZnO NPs size increased and their dissolution decreased with increasing in pH. Leaching distance of ZnO NPs was less than 2.5 cm, indicating that ZnO NPs had a little potential to leach into deeper soil layers. When ZnO NPs were exposed to plant, the total weights of plants decreased. The effects on the length of root and shoot were not observed. In addition large amount of ZnO NPs were adsorbed on the surface of plant root and didn't translocate into shoot. These results suggest that ZnO NPs block the pores of the root cell wall and decrease the bioavailability of plant nutrients. Therefore it can be speculated that the particles increase in size and settle down in the water environment and may adversely affect the plant growth by firmly adhering to the root surface when the ZnO NPs are exposed to the environment.

• Journal of the Korean Vacuum Society
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• v.22 no.3
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• pp.138-143
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• 2013

Recently, ZnO nanoparticles have been studied in various application fields due to their physico-chemical properties. In this study, we have researched on the ZnO photocatalytic activity by redox reaction. ZnO nanoparticles have low photocatalytic activity in comparison with $TiO_2$ nanoparticles because it has the disadvantage that the formation of $Zn(OH)_2$ in water solvent. Therefore, we were synthesized ZnO nanoparticles by spray-pyrolysis method, and then studied on stability in water solvent. At the results, the water treated-ZnO nanoparticles showed higher photocatalytic activity than non-treated ZnO nanoparticles because molecular $H_2O$ was increased onto the ZnO surface under the water treatment. Also, we confirmed that the ZnO nanoparticles synthesized by spray-pyrolysis method is very stable in the water solvent.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.467-472
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• 2009

Seedling growth test is used to assess toxicity of nanoparticles (NPs). This study evaluates toxicity of zinc, zinc oxide NPs on Cucumis sativus using two methods; phytagel and filter paper. From the comparison, phytagel method prevents precipitation of water insoluble NPS. Seeding length was negatively related to the exposed concentration of Zn, ZnO NPs in filter method. The median effective concentrations (EC50) for C. sativus exposed to Zn, ZnO NPs were estimated about 598, 600 mg/L in filter method. Bioaccumulation increased with the exposed concentration of Zn, ZnO NPs in only filter method. The results showed that the filter paper method was much better protocol than phytagel method.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.34 no.4
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• pp.117-124
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• 2024

Zinc oxide nanoparticles were synthesized using the polyol method with ethylene glycol containing hydroxyl groups (-OH). It was confirmed that the zinc compounds prepared by the polyol method were a mixture of zinc carbonate hydroxide (Zn₅(OH)₆(CO₃)₂) and zinc oxide (ZnO) crystalline structures. Calcination at 400℃, 600℃ and 800℃ was performed to examine the effects of calcination temperature on the particle size, morphology and crystallinity of zinc oxide. ZnO powders of calcination at 800 ℃ was evaluated to particle size analysis from ethylene glycol containing precursor solution compared with distilled water based solution. The zinc oxide particles obtained from the former had a particle size of approximately 404 ± 51 nm, whereas those from the latter exhibited a more uniform nanoparticles morphology with a particle size of approximately 109 ± 29 nm. This demonstrates that the addition of ethylene glycol can control the influence of water molecules, enabling the direct synthesis of zinc oxide in the form of uniform nanoparticles.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.243-244
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• 2012

산화아연 나노구조를 금을 금속촉매로 사용하여 실리콘 기판위에 기상이동법으로 성장하였다. 성장할 때 소스(source)와 기판 사이의 거리는 5에서 50 mm로 변화를 주며 아르곤과 산소 분위기에서 $900^{\circ}C$로 성장하였다. 산화아연 나노구조의 구조적 및 광학적 특성을 조사하기 위해 field-emission scanning electron microscopy, X-ray diffraction (XRD), 그리고 photoluminescence (PL)를 이용하였다. 산화아연 나노구조는 나노선과 나노입자의 형태로 성장하였다. 산화아연 나노구조의 광학적 특성은 소스와 기판사이의 거리가 가까울수록 향상되었다. 특히, 소스와 기판사이의 거리가 5 mm 일 때, 산화아연 나노선이 관찰되었으며 XRD 와 PL 분석에서 나타난 반가폭 (full width at half maximum)은 $0.061^{\circ}$ 와 96 meV로써 가장 작았다. 산화아연 나노선은 산화아연 나노입자와 비교하여, 결정성 및 광학적 특성이 우수하였다.

• Journal of the Korean Vacuum Society
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• v.21 no.4
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• pp.205-211
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• 2012

We investigated the optical and hydrophobic properties of the deposited silver (Ag) zinc oxide (ZnO) nanorods (NRs) on flexible indium tin oxide (ITO) coated polyethylene terephthalate (PET) substrates (i.e., ITO/PET). The ZnO NRs were grown by an electrochemical deposition using a sputtered ZnO seed layer and the Ag was deposited by using a thermal evaporator. For comparison, the same fabrication process was carried out on the bare ITO/PET without ZnO NRAs. Due to the discrete surface of ZnO NRs, the deposited Ag was formed as nano-scale particles, while the Ag became film-like for bare ITO/PET. In order to control the size and amount of Ag particles, the Ag deposition time was changed from 100 to 600 s. When the deposition time was increased, the Ag particles became larger and denser, and the absorptance was increased. This enhanced absorptance may be due to the localized surface plasmon resonance of Ag particles. Furthermore, the relatively high hydrophobicity was observed for the deposited Ag on the ZnO NRs/ITO/PET. These improved optical and surface properties are expected to be useful for flexible photovoltaic and optoelectronic devices.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.12
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• pp.1129-1134
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• 2009

Increasing application of nanotechnology highlights the need to clarify nanotoxity and nanoparticles characterization. However, few researches have focused on phytotoxicity of nanoparticles. This study was to examine phytotoxicity on Cumumis sativus seedling and the dissolution of Zn, ZnO nanoparticles in hydroponic culture system. Results of this study; characteristics of Zn, ZnO nanoparticles are more aggregated in nutrient solution than deionized water. C. sativus biomass significantly reduced in the nutrient solution were higher than 100 mg/L, and Zn toxicity showed $Zn^{2+}$> Zn> ZnO NPs. Results of transmission electron microscopy images, Zn and ZnO nanoparticles greatly adhered onto the root cell wall and nanoparticles were observed in the root cell.

• Elastomers and Composites
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• v.49 no.3
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• pp.191-198
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• 2014

We synthesized thermoplastic polyurethane elastomer(TPU) with acid group and nano zinc oxide, and characterized their mechanical properties, thermal properties, contact angle and grip property. The effects of the zinc oxide content and size on the physical property of TPU were investigated. When the nano zinc oxide was introduced in TPU with acid group, it had excellent mechanical properties and grip by formation of hydrogen and ionic bonding. The wet slip of TPU with zinc oxide was increased continuously as ionization rate increased due to increase of hydrophilicity and ionic interaction, and mechanical properties were increased with increasing ionization rate up to 50%.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.110-110
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• 2012

아라미드 섬유소재는 고강도, 고내열성의 소재로 다양한 용도전개가 가능하나, 일광 및 부식에 의한 내광성 및 내후성이 급격하게 저하되는 단점이 있다. 자외선의 광화학적 작용에 의해 변퇴, 경화, 취하, 강도저하가 일어나는 단점을 보완하기 위해 내광성 및 내화학성이 우수한 전이금속산화물 소재와의 복합화를 통해 내광성 및 내화학성 개선에 대하여 연구하였다. zinc acetate 수화물과 수산화리튬을 무수에탄올로 용해시킨 용액을 강하게 교반하여 나노 산화아연 졸을 제조하였다. 제조된 나노크기의 zinc oxide 입자의 형상과 입자분포 등 제조특성을 입도분석기, FE-SEM 및 EDS 분석을 통하여 고찰하였으며, 제조된 나노졸을 아라미드 섬유에 침지시켜 Xenon-arc 내후성시험기에서 80시간 동안 노출시켜 노출시간에 따른 물성변화를 분석하였다. 나노졸을 5~20% 픽업으로 패딩한 후 광에 노출된 아라미드의 인장강도는 나노졸을 처리하지 않은 아라미드 섬유보다 20~30% 개선된 인장강도를 나타내었다.

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.171-172
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• 2002

나노미터 규모의 작은 충전제 입자는 마이크로 미터 규모의 일반적인 충전제 입자에 비해서 많은 다른 점이 발견되어 왔다. 이 연구에서는 최근에 알게된 입경이 100nm 이하인 ZnO 입자가 radical 중합된 고분자의 열안정성을 향상시키는 현상을 보다 자세하게 연구한 것이다. HDPE, LDPE, LLDPE, PP 및 PS를 열분해가 아주 느리게 일어나는 낮은 RPM으로 Haake사의 Torque Rheometer의 internal mixer 안에서 녹인 후 평균입경 49nm인 ZnO 나노입자를 약4분간 충부히 분산되도록 혼합하고 50 RPM으로 혼합속도를 높여서 시간에 따른 Trque의 변화를 측정하므로써 열안정성 효과를 관찰하였다. (중략)