• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1716-1717
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• 2011

잉크젯으로 인쇄된 실버 나노입자가 오븐, 레이저, 전기를 이용한 소결방법에 의해 소결되었다. 전도성 라인은 드롭 온 디맨드형(drop-on-demand) 잉크젯 프린터에 의해 유리 기판 위에 인쇄되었다. 레이저를 이용한 소결은 레이저 강도와 조사시간을 변화시키면서 실버나노입자를 소결하였고, 전기 소결은 인쇄된 라인에 정전류 방식을 이용하여 인가해주는 전류값을 변화시키면서 소결하였다. 소결방법에 따른 비저항변화, 단면적 변화, 미세구조변화를 관찰하였고 이 결과를 오븐 소결 결과와 비교하였다. 전기를 이용하여 소결하였을 경우 가장 낮은 비저항을 얻을 수 있었고, 은의 고유 비저항에 비하여 1.7배 큰 비저항을 얻었다.

• Composites Research
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• v.23 no.1
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• pp.31-36
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• 2010

The improvement of electrical conductivity of carbon-fiber reinforced plastics (CFRP) has been investigated by silver nano-particles coating for the purpose of lightning strike protection. Silver nano-particles in colloid were sprayed on the surface of carbon fibers, which were then impregnated by epoxy resin to form a CFRP specimen. Electrical resistance was measured by contact resistance meter which utilize the principles of the AC 4-terminal method. Electrical resistance value was then converted to electrical conductivity. The coated silver nano-particles on the carbon fibers were verified by SEM and EDS. The electrical conductivity was increased by three times of the ordinary CFRP.

• Journal of Life Science
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• v.31 no.9
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• pp.862-872
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• 2021

Recent studies on synthesis of metallic nanomaterials such as silver (Ag), gold (Au), platinum (Pt), cerium (Ce), zinc (Zn), and copper (Cu) nanoparticles (NPs) using plants and microbes are attracted researchers for their wide range of applications in the field of biomedical sciences. The plant contains abundant of bioactive contents such as flavonoids, alkaloids, saponins, steroids tannins and nutritionals components. Similarly, microbes produce bioactive metabolites, proteins and secretes valuable chemicals such as color pigments, antibiotics, and acids. Recently reported, biogenic synthesis of NPs in non-hazardous way and are promising candidates for biomedical applications such as antibacterial, antifungal, anti-cell proliferative and anti-plasmodia activity. All those activities are dose dependent, along with their shape and size also matters on potential of NPs. Microbes and plants are great source of metabolites, those useful in biomedical field, such metabolites or chemicals involved in synthesis of NPs in an ecofriendly way. NPs synthesized using microbes or plant materials are reveals more non-toxic, facile, and cost-effective compare to chemically synthesized NPs. In present review we are focusing on NPs synthesis using biological agents such as microbes (bacteria, fungi and algae) and plant, characterization using different techniques and their antibacterial applications on pathogenic Gram-positive and Gram-negative organisms.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.3
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• pp.205-213
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• 2013

This study was to improve cosmetical activity of thiamine di-lauryl sulfate (TDS) by encapsulation of nanoparticle with lecithin. Results showed that most of the nanoparticles containing the TDS were well formed in round shape with below 150 ~ 200 nm diameter as well as they were fairly stable in various pH ranges by measuring zeta potentials. The nanoparticles of TDS resulted in 85% cell viability of human normal fibroblast cells (CCD-986sk) when added at the highest concentration (1.0 mg/mL). The nanoparticles of Acer mono sap showed highest free radical scavengering effect as 88.1% in adding sample (1.0 mg/mL), compared to TDS solution of non-encapsulation (81.6%). The nanoparticles of TDS reduced the expression of MMP-1 on UV-irradiated CCD-986sk cells down to as 41.4%. The TDS solution and nanoparticles showed significant anti-microbial activities agaionst the salmonella typhimurium and listeria monocytogenes at 5 and 6 days as compared with control. Anti-microbial activities of TDS nanoparticles were similar to positive control. These results indicated that TDS nanoparticles may be a source for functional cosmetic agents capable of improving cosmetical activity such as antioxidant, whitening, and anti-wrinkling effects and can be further developed as natural preservative in cosmetics.

• Membrane Journal
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• v.25 no.1
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• pp.1-6
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• 2015

It was known that the polarlized surface of silver nanoparticles could be interacted revesibly with olefin molecules for facilitated olefin transport. However, it was thought that it can be regenerated by interaction between oxide surface of AgNPs and olefin molecules because the surface of the silver nanoparticles is easily oxidized in the air. In order to investigate the effect of the silver oxide, 5 wt% AgO or $Ag_2O$ was dispersed in polymer PVP solutions and 0.005~0.02% electron acceptor as TCNQ or p-BQ were added to fabricate the separation membrane. After the addition of the electron acceptor, it was expected to improve the polarity on the surface of the silver oxide and the degree of dispersion. The characteristics of the separation membrane were identified by the gas permeance, XPS and TEM.

• Applied Chemistry for Engineering
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• v.27 no.6
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• pp.669-671
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• 2016

Hydroxyapatite (HAP) was prepared by a hydrothermal synthesis method and also silver was introduced on the surface of HAP through an ion exchange reaction. The crystal phase and morphology of HAP were then evaluated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). In addition, the absorption property of HAP was characterized by diffuse reflectance UV-Vis spectroscopy. The presence of silver nanoparticles on the surface of HAP was also verified by XRD and TEM analysis. Particularly, the silver doped HAP showed an enhanced absorption property in UV-Vis region compared to that of the pristine HAP.

• Journal of the Korean Magnetics Society
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• v.22 no.2
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• pp.37-41
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• 2012

The Ag nanoparticles attached $La_{0.7}Sr_{0.3}Co_{0.3}Fe_{0.7}O_{3-{\delta}}$ (LSCF) perovskites were prepared by plasma method. The Ag nanoparticles with size of several nanometers deposited from the Ag target were coated on the surface of LSCF powders with size range from 0.2 to 3 ${\mu}m$. The agglomeration of Ag particles annealed at $800^{\circ}C$ under inert gas of Ar were rarely observed. The inter-diffusion between surface Ag and core LSCF is effectively strong to prevent aggregation of Ag nanoparticles. The wave number of FT-IR spectra for LSCF were largely shifted as the concentration of Ag on LSCF up to 2.11 wt.%. The ionic states of irons in LSCF were measured by M$\ddot{o}$ssbauer spectroscopy. The small amount of $Fe^{4+}$ ions are converted to $Fe^{3+}$ ions after Ag nanopartcles were coated on LSCF.

• Korean Chemical Engineering Research
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• v.61 no.3
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• pp.439-445
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• 2023

In this study, silver nanoparticles were synthesized by reducing silver nitrate with PVA, and the solution prepared by adding carboxymethyl cellulose (CMC) to the silver nanoparticles was coated on a PET substrate to prepare a coating film with antibacterial and antifogging function. When the coating films were in contact with water vapor at 80 ℃, the uncoated PET substrate was blurred due to the scattering of light due to the occurrence of fog, while the coating film coated with silver nanosol with CMC remained transparent despite contact with water vapor, showing excellent antifogging function. In addition, the antibacterial properties of the coating films were measured by film adhesion method for Staphylococcus aureus, gram-positive bacteria, and Escherichia coli, gram-negative bacteria. The uncoated PET substrate showed a large number of colonies of Staphylococcus aureus and Escherichia coli, while the coating film coated with the silver nanosol greatly inhibited the growth of Staphylococcus aureus and Escherichia coli, resulting in excellent antibacterial effect.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.spc
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• pp.1-3
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• 2009

Silver nanoparticles have been used in agricultural practice because of their biocide effect. However, limited information is available for the effect of silver nanoparticles on soil quality. Therefore, the main purpose of this study was to evaluate effect of silver nanoparticle application on soil especially when fertilizer is applied. To simulate potassium fertilizer, potassium chloride was mixed with silver nanoparticles in soil. Concentration of silver and chloride was measured and result showed that concentration of both compounds was decreased at the range of $3.4mg\;kg^{-1}$ and 78-84% respectively after treatment. In addition, analysis of microbial population after treatment showed that microbial population was increased when silver nanoparticles and KCl were mixed. Those results indicated that application of fertilizer has impact on biocide effect of silver nanoparticles in soil.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.2
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• pp.119-124
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• 2013

In this study, the two-dimensional transient temperature of printed Ag nanoparticle ink during continuous wave laser sintering was calculated. Ag nanoparticle ink was printed on a glass substrate by inkjet printing. Then, a 532-nm continuous wave laser with different laser intensities was irradiated on the printed Ag nanoparticle ink for 60 s. During laser irradiation, the in-situ specific resistance of the sintered ink was measured. To obtain the transient temperature of the sintered ink during the laser sintering process, a two-dimensional transient heat conduction equation was derived by applying the Wiedemann-Franz law. It was found that the specific resistance of the sintered ink decreased with an increase in the sintering temperature of the printed ink.