• Elastomers and Composites
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• 제49권3호
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• pp.191-198
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• 2014

산성기를 도입한 폴리우레탄에 나노산화아연을 첨가하여 열가소성 폴리우레탄 탄성체를 합성하였으며, 합성된 폴리우레탄 탄성체의 기계적물성, 열적특성, 접촉각, 그립특성을 평가하였다. 그리고 산화아연의 함량과 입자 크기가 폴리우레탄 탄성체에 미치는 영향에 대해서 연구하였다. 나노산화아연을 도입한 경우 이온결합이 형성되어 산성기에 의한 수소결합과 동시에 작용하기 때문에 인장강도, 마모 등 기계적 물성 및 그립특성이 향상되는 것이 확인되었다. 폴리우레탄내의 산화아연 함량에 따른 물성평가 결과 나노산화아연 함량이 증가할수록 이온결합 도입에 의한 친수성이 커져서 wet slip이 지속적으로 상승되었으며, 기계적 물성은 산화아연에 의한 이온화율 50%까지 향상되다가 그 이후에는 감소되는 현상을 나타내었다.

• 대한화장품학회지
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• 제47권1호
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• pp.1-7
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• 2021

전 세계적으로 자외선 차단제의 유효성 및 안전성에 대한 관심이 증가함에 따라 새로운 무기 자외선 차단제 개발에 대한 연구도 활기를 띄고 있다. 본 연구에서는 최근에 이슈화된 나노물질규제에 대응 가능한 나노 사이즈가 아닌 non-nano 막대형 산화아연을 합성하였고, 이를 세틸알코올로 표면처리한 막대형 산화아연분체를 개발하여 물리적 특성을 조사하였으며 자외선 차단제로서의 응용가능성을 평가하였다. 실험 결과, non-nano인 막대형 산화아연 분체를 적용한 선크림의 자외선 차단 효능과 백탁 정도는 40 nm 크기의 산화아연과 비슷한 결과를 나타냈으며, 막대형 산화아연 분산액을 사용한 선크림은 자외선 차단효능이 현저히 증가함을 확인하였다. 따라서 본 연구를 통해 개발된 막대형 산화아연 분체는 non-nano (200 nm)임에도 불구하고 투명성(백탁 개선), 자외선 차단 효능 그리고 사용감 측면에서 우수한 자외선 차단제로서 응용 가능성이 있음을 시사하였다.

• 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.

• Journal of Veterinary Science
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• 제24권1호
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• pp.3.1-3.13
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• 2023

Background: Zinc (Zn) is an essential cofactor for physiological homeostasis in the body. Zn oxide (ZnO), an inorganic compound that supplies Zn, exists in various sizes, and its bioavailability may vary depending on the size in vivo. However, comparative studies on the nutritional effects of micro-sized ZnO (M-ZnO) and nano-sized ZnO (N-ZnO) supplementation on Zn deficiency (ZnD) animal models have not been reported. Objectives: This study investigated the nutritional bioavailability of N-ZnO and M-ZnO particles in dietary-induced ZnD mice. Methods: Animals were divided into six experimental groups: normal group, ZnD control group, and four ZnO treatment groups (Nano-Low, Nano-High, Micro-Low, and MicroHigh). After ZnD induction, N-ZnO or M-ZnO was administered orally every day for 4 weeks. Results: ZnD-associated clinical signs almost disappeared 7 days after N-ZnO or M-ZnO administration. Serum Zn concentrations were higher in the Nano-High group than in the ZnD and M-ZnO groups on day 7 of ZnO treatment. In the liver and testis, Nano-Low and Nano-High groups showed significantly higher Zn concentrations than the other groups after 14-day treatment. ZnO supplementation increased Mt-1 mRNA expression in the liver and testis and Mt-2 mRNA expression in the liver. Based on hematoxylin-and-eosin staining results, N-ZnO supplementation alleviated histological damage induced by ZnD in the testis and liver. Conclusions: This study suggested that N-ZnO can be utilized faster than M-ZnO for nutritional restoration at the early stage of ZnD condition and presented Mt-1 as an indicator of Zn status in the serum, liver, and testis.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2012년도 제46차 학술발표회
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• pp.66-66
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• 2012

최근 환경파괴, 병원성 세균감염 등 각종질병과 환경문제로 인한 피부염 등 우리 몸을 보호하기 위하여 친환경 소재의 용품들이 소비자들의 이목을 끌고 있다. 또한, 부가가치를 높이고 특수한 기능성을 나타내는 기능성 섬유에 대한 관심이 증가하고 있으며 이러한 기능성 섬유들 중에서 항균성을 가지는 천연섬유를 주제로 연구를 진행하고 있다. 대표적인 천연섬유인 면 직물에 Zinc alginate로 코팅시켜 부가적인 기능들을 부여시키는 방법으로 실험을 진행하였다. 미처리 면직물과 Zinc alginate가 코팅 된 면직물을 서로 비교하여 분석하였다. 증류수와 생리식염수로 흡습량과 흡습시간을 동시에 측정 후 비교하였으며 접촉각은 Contact angle system OCA20을 이용하여 측정하였다. Zinc alginate의 흡착량은 EDS(EX-250, HORIBA, Japan)를 이용하여 확인하였다. 표면과 단면의 형태는 주사전자현미경(S-4100, Hitachi Co., Japan)으로 x300, x500 배율로 측정하였다.

• Journal of Magnetics
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• 제11권1호
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• pp.1-4
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• 2006

We report on the growth, structural and transport properties of zinc-blende CrAs/GaAs/MnAs/GaAs multilayers on GaAs(001) substrates. Structural analyses using in-situ reflection high-energy electron diffraction and exsitu cross-sectional transmission electron microscopy confirmed the realization of a zinc-blende crystal structure. Room temperature Hall measurements reveal that the as-grown multilayer exhibits p-type conductivity with a very low resistivity of $0.052\;\omega{cm}$, a high carrier concentration of $6.2X10^{19}\;cm^{-3}$ and a Hall mobility of $1.8\;cm^2/Vs$. We also observed a clear decrease of the resistivity in samples after low temperature annealing.

• Restorative Dentistry and Endodontics
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• 제39권2호
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• pp.109-114
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• 2014

Objectives: Recurrent caries was partly ascribed to lack of antibacterial properties in composite resin. Silver and zinc nanoparticles are considered to be broad-spectrum antibacterial agents. The aim of the present study was to evaluate the antibacterial properties of composite resins containing 1% silver and zinc-oxide nanoparticles on Streptococcus mutans and Lactobacillus. Materials and Methods: Ninety discoid tablets containing 0%, 1% nano-silver and 1% nano zinc-oxide particles were prepared from flowable composite resin (n = 30). The antibacterial properties of composite resin discs were evaluated by direct contact test. Diluted solutions of Streptococcus mutans (PTCC 1683) and Lactobacillus (PTCC 1643) were prepared. 0.01 mL of each bacterial species was separately placed on the discs. The discs were transferred to liquid culture media and were incubated at $37^{\circ}C$ for 8 hr. 0.01 mL of each solution was cultured on blood agar and the colonies were counted. Data was analyzed with Kruskall-Wallis and Mann-Whitney U tests. Results: Composites containing nano zinc-oxide particles or silver nanoparticles exhibited higher antibacterial activity against Streptococcus mutans and Lactobacillus compared to the control group (p < 0.05). The effect of zinc-oxide on Streptococcus mutans was significantly higher than that of silver (p < 0.05). There were no significant differences in the antibacterial activity against Lactobacillus between composites containing silver nanoparticles and those containing zinc-oxide nanoparticles. Conclusions: Composite resins containing silver or zinc-oxide nanoparticles exhibited antibacterial activity against Streptococcus mutans and Lactobacillus.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.236.1-236.1
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• 2015

The surface morphology of front transparent conductive oxide (TCO) films is very important to achieve high current density in amorphous silicon (a-Si) thin film solar cells since it can scatter the light in a better way. In this study, we present the low cost hydrothermal deposited uniform zinc oxide (ZnO) nano-flower structure with various aspect ratios for a-Si thin film solar cells. The ZnO nano-flower structures with various aspect ratios were grown on the RF magnetron sputtered AZO films. The diameters and length of the ZnO nano-flowers was controlled by varying the annealing time. The length of ZnO nano-flowers were varied from 400 nm to $2{\mu}m$ while diameter was kept higher than 200 nm to obtain different aspect ratios. The ZnO nano-flowers with higher surface area as compared to conventional ZnO nano structure are preferred for the better light scattering. The conductivity and crystallinity of ZnO nano-flowers can be enhanced by annealing in hydrogen atmosphere at 350 oC. The vertical aligned ZnO nano-flowers showed higher haze ratio as compared to the commercially available FTO films. We also observed that the scattering in the longer wavelength region was favored for the high aspect ratio of ZnO nano-flowers. Therefore, we proposed low cost and vertically aligned ZnO nano-flowers for the high performance of thin film solar cells.

• Advances in materials Research
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• 제4권4호
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• pp.193-205
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• 2015

Contamination by bacterial strands is a major problem after bone replacement surgeries, so there is a great need to develop low cost biocompatible antibacterial bioactive scaffolds to be used in bone tissue engineering. For this purpose, nano-zinc doped hydroxyapatite with different zinc-concentrations (5, 10 and 15 mol%) was successfully prepared by the wet chemical precipitation method. The prepared powders were used to form porous scaffolds containing biodegradable Ca-cross-linked alginate (5%) in order to enhance the properties of alginate scaffolds. The scaffolds were prepared using the freeze-gelation method. The prepared powders were tested by X-ray diffraction; transmission electron microscope and Fourier transform infrared analyses, while the prepared scaffolds were investigated by Fourier transform infrared analyses, thermogravimetric analyses and measurement of the antibacterial properties. Best results were obtained from scaffold containing 15% mol zinc-doped hydroxyapatite powders and 5% alginate concentration with ratio of 70:30.

• Bulletin of the Korean Chemical Society
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• 제33권4호
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• pp.1235-1241
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• 2012

Aluminium (Al)-doped zinc oxide (AZO) thin films with different Al concentrations were prepared by the solgel spin-coating method. Optical parameters such as the optical band gap, absorption coefficient, refractive index, dispersion parameter, and optical conductivity were studied in order to investigate the effects of the Al concentration on the optical properties of AZO thin films. The dispersion energy, single-oscillator energy, average oscillator wavelength, average oscillator strength, and refractive index at infinite wavelength of the AZO thin films were found to be affected by Al incorporation. The optical conductivity of the AZO thin films also increases with increasing photon energy.