• 마이크로전자및패키징학회지
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• 제25권1호
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• pp.11-15
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• 2018

본 논문에서는 UV 나노임프린트 공정으로 제작한 나노 콘 형태의 구조물 위에 은 나노 입자를 증착하여 광증폭용 구조 형태를 제작하고자 하였다. 은 나노 입자의 증착은 하부 기판 표면의 젖음 특성에 따른 액적의 증발 거동을 이용하였으며, 기판 하부 열에너지의 차이에 따라서 액적 중심부부터 가장자리까지 증착 형태가 변화함을 확인하였다. 제작한 구조 형태와 유사한 구조를 시간영역 유한차분(FDTD)법을 통해 광 특성을 예측하여, 최종적으로 제작한 구조의 은나노 입자 부근에 에너지가 집중되는 결과를 확인하였다.

• Advances in nano research
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• 제4권4호
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• pp.281-294
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• 2016

The advantages of nano-scale materials (size 1-99 nm in at least in one dimension) could be realized with their potential applications in diversified avenues. Herein, we report for the first time on the successful synthesis of homogeneous epoxy coatings containing phytogenic silver nanoparticles (Ag) on PVC and glass substrates by room-temperature curing of fully mixed epoxy slurry diluted by acetone. Alstonia scholaris bark extract was used to reduce and stabilize the silver ions. The surface morphology and mechanical properties of these coatings were characterized using the techniques like, UV-Vis (UV-Visible) spectrophotometry, X-ray diffraction (XRD), Fourier transform infrared spectrophotometry (FT-IR), Epifluorescence microscopy and scanning electron microscopy (SEM). The effect of incorporating Ag nanoparticles on the biofilm (scale) resistant epoxy-coated PVC was investigated by total viable counts ($CFU/cm^2$) from epoxy coating from (Initial) $1^{st}$ day to $25^{th}$ days. The phytogenic Ag nanoparticles were found to be significantly improving the microstructure of the coating matrix and thus enhanced the anti-biofilm performance of the epoxy coating. In addition, the antimicrobial mechanism of Ag nanoparticles played an important role in improving the anti-biofilm performance of these epoxy coatings.

• Bulletin of the Korean Chemical Society
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• 제29권12호
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• pp.2368-2372
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• 2008

• Bulletin of the Korean Chemical Society
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• 제26권5호
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• pp.837-840
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• 2005

• 한국분말재료학회지
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• 제25권3호
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• pp.232-239
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• 2018

In this paper, the recovery and nanoparticle synthesis of Ag from low temperature co-fired ceramic (LTCC) by-products are studied. The effect of reaction behavior on Ag leaching conditions from the LTCC by-products is confirmed. The optimum leaching conditions are determined to be: 5 M $HNO_3$, a reaction temperature of $75^{\circ}C$, and a pulp density of 50 g/L at 60 min. For the selective recovery of Ag, the [Cl]/[Ag] equivalence ratio experiment is performed using added HCl; most of the Ag (more than 99%) is recovered. The XRD and MP-AES results confirm that the powder is AgCl and that impurities are at less than 1%. Ag nanoparticles are synthesized using a chemical reduction process for recycling, $NaBH_4$ and PVP are used as reducing agents and dispersion stabilizers. UV-vis and FE-SEM results show that AgCl powder is precipitated and that Ag nanoparticles are synthesized. Ag nanoparticles of 100% Ag are obtained under the chemical reaction conditions.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.88.1-88.1
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• 2015

In recent printed electronics technology, Photo-Sintering, a technique for sintering materials using a light source, has attracted attention as an alternative to time-consuming high-temperature thermal processes. The key principle of this technique is the selective heating of a strongly absorbent thin film, while preventing the heating of the transparent substrate by the light source. Many recent studies have used a flash lamp as the light source, and investigated the material-dependent effect of the width or intensity of the pulsed light. However, the flash lamp for sintering is not suitable for industry yet, because of needing too high power to sinter for a large scale. In energy-saving and large-scale sintering, LED technologies would be very useful in the near future. In this work, we investigated a sintering process for silver nanoparticles using UV-LED array. Silver nanoparticles in ink were inkjet-printed on a $1{\times}1cm$ area of a PET film and photo-sintered by 365 nm UV-LED module. A sheet resistance value as low as $72.6m{\Omega}/sq$ (2.3 - 4.5 times that of bulk silver) was obtained from the UV-LED sintering at 300 mW/cm2 for 50 min.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권1호
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• pp.104-110
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• 2016

The transport of silver nanoparticles (AgNPs) was investigated through a column packed with sand. A series of column experiments were carried out to evaluate the effect of ionic strength (IS), pH, electrolyte type and clay mineral on mobility of polyvinylpyrrolidone-coated silver nanoparticles (PVP-AgNPs). The deposition of PVP-AgNPs was increased with increasing solution ionic strength and decreasing pH. Furthermore, the depositon of PVP-AgNPs was affected by the electrolyte type (NaCl vs. NaNO₃) and was shown to be greater at NaNO₃ solution. Also, the transport of PVP-AgNPs was greatly increased after the pre-deposition of clay particles on sand. Our results suggest that various environmental factors can influence the mobility of PVP-AgNPs in soil-groundwater systems and should be carefully considered in assessing their environmental risks.

• Advances in nano research
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• 제10권2호
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• pp.139-150
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• 2021

In this study, phytochemicals present in Propolis Extract (PE) were employed as reducing and stabilizing reagents to synthesize silver nanoparticles. Three propolis-reduced silver nanoparticles (P-AgNPs1-3) were synthesized using increasing amounts of PE. P-AgNPs were treated with different cancer cells-lung (A549), cervix (HeLa) and colon (WiDr) - for 24, 48 and 72 h to evaluate their anti-proliferative activities. A non-cancerous cell type (L929) was also used to test whether suppressive effects of P-AgNPs on cancer cell proliferation were due to a general cytotoxic effect. The characterization results showed that the bioactive contents in propolis successfully induced particle formation. As the amount of PE increased, the particle size decreased; however, the size distribution range expanded. The antioxidant capacity of the particles increased with increased propolis amounts. P-AgNP1 exhibited almost equal inhibitory effects across all cancer cell types; however, P-AgNP2 was more effective on HeLa cells. P-AgNPs3 showed greater inhibitory effects in almost all cancer cells compared to other NPs and pure propolis. Consequently, the biological effects of P-AgNPs were highly dependent on PE amount, NP concentration, and cell type. These results suggest that AgNPs synthesized utilizing propolis phytochemicals might serve as anti-cancer agents, providing greater efficacy against cancer cells.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.307-307
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• 2006

The reduction behavior of silver ions to silver nanoparticles is an important research topic in polymer/silver salt complex membranes for facilitated olefin transport, because it has a significant effect on the long-term stability of membrane performance. In this study, the effects of solvent on the formation of silver nanoparticles and long-term membrane performance in polymer/silver salt complex membrane were investigated. This effect was assessed for the complexes of poly(N-vinyl pyrrolidone) $(PVP)/AgBF_{4}$ with the use of ionic liquid (IL), acetonitrile (ACN) and water as a solvent. Membrane performance test shows that long-term stability is strongly dependent on the kind of solvent and arranged: IL > ACN >> water.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2251-2256
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• 2014

We have successfully decorated reduced graphene oxide (RGO) with silver nanoparticles (AgNPs) by microwaving silver alkylcarbamate for 13 seconds using 1-amino-4-methylpiperazine. Uniform AgNPs (20-40 nm) were effectively prepared, and 1-amino-4-methylpiperazine acted as a reaction medium, reducing agent, and stabilizer. Particle size and morphology were correlated with the silver alkylcarbamate concentration and microwave time. The graphene/AgNPs composites were characterized by Raman, X-ray diffraction, and scanning electron microscopy to confirm that the AgNPs were uniformly decorated onto the graphene. Measurements of the transparent conductive property at room temperature indicated that these graphene/AgNPs nanosheets with 55.45% transmittance were electrically continuous with a sheet resistance of approximately $43{\Omega}/{\Box}$.