• Title/Summary/Keyword: silver materials

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Facile Synthesis of Silver Chloride Nanocubes and Their Derivatives

  • Kim, Seung-Wook;Chung, Haeg-Eun;Kwon, Jong-Hwa;Yoon, Ho-Gyu;Kim, Woong
    • Bulletin of the Korean Chemical Society
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    • v.31 no.10
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    • pp.2918-2922
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    • 2010
  • We demonstrate a facile route to synthesize silver chloride nanocubes and derivative nanomaterials. For the synthesis of silver chloride nanocubes, silver nitrate and hydrochloric acid were used as precursors in ethylene glycol, and poly (vinyl pyrrolidone) as a surfactant. Molar ratio of the two precursors greatly influenced the morphology and composition of the final products. As-synthesized silver chloride nanocubes showed size-dependent optical properties in the visible region of light, which is likely due to a small amount of silver clusters formed on the surface of silver chloride nanocubes. Moreover, we show for the first time that simple reduction of silver chloride nanocubes with different reducing reagents leads to the formation of delicate nanostructures such as cube-shaped silver-nanoparticle aggregates, and silver chloride nanocubes with truncated corners and with silver-nanograin decorated corners. Additionally, we quantitatively investigated for the first time the evolution of silver chloride nanocubes to silver chloride nanocubes decorated with silver nanoparticles upon exposure to e-beam. Our novel and facile synthesis of silver chloride related nanoparticles with delicately controlled morphologies could be an important basis for fabricating efficient photocatalysts and antibacterial materials.

Printability of synthesized Silver Nano sol in Micro-patterning of Electrode on ITO Glass

  • Ryu, Beyong-Hwan;Park, Han-Sung;Byun, Jong-Hoon;Choi, Young-Min;Kong, Ki-Jeong;Lee, Jeong-O;Chang, Hyun-Ju
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.981-984
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    • 2004
  • We have studied a printability of synthesized silver nano solon ITO glass substrate. The highly concentrated polymeric dispersant-assisted silver nano sol was prepared by variation of molecular weight and control of initial nucleation and growth of silver nanoparticles, to achive dispersion stability and controlling the size of silver nanoparticles. The synthesized silver nano-sol was tested for printability to explore the possibility of micro-electrodes patterning on ITO glass substrate. The silver micro-electrode with 50${\sim}100{\mu}m$ line width was formed on ITO glass substrate.

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Effect of Surfactant on Synthesis of Colloidal Ag Nanoparticles (콜로이드 Ag 나노입자 합성시 계면활성제의 영향)

  • Lee Jong-Kook;Choi Nam-Kyu;Seo Dong-Seok
    • Korean Journal of Materials Research
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    • v.15 no.5
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    • pp.340-347
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    • 2005
  • Silver nanoparticles were synthesized by chemical reduction method from aqueous silver nitrate solution ana hydrazine as a reduction agent. The morphology, particle size and shape were dependent on the mixing method, reaction temperature and time, molar ratio of hydrazine and silver nitrate, the kind of surfactant, and the addition of surfactant. The stability of the colloidal silver was achieved by the adsorption of surfactant molecules onto the particle. Silver nanoparticles have a characteristic absorption maximum at 430 nm under UV irradiation. It was found that the colloid was nanometer m size and formed very stable dispersion of silver. The Ag nanoparticles obtained showed the spherical shape with the size range of 10-30 nm.

Silver Materials Induce Differential Cytotoxicity and Pulmonary Toxicity Based on Size and Shape

  • Pak, Pyo June;Kang, Beob Hwa;Chung, Namhyun
    • Journal of Applied Biological Chemistry
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    • v.58 no.2
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    • pp.113-116
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    • 2015
  • Silver materials may be toxic in humans because they can enter the body and accumulate, typically in the lungs. We hypothesized that the cytotoxicity of naive silver materials is affected by their size and shape. Our in vitro assays revealed that the overall toxicity was in the following order: submicro-particles>wires>micro-particles. These results contrast with previous studies, which showed that silver wires are the most toxic among the three tested materials, possibly due to differences in cell lines. Evaluations of in vivo pulmonary toxicity revealed eryptosis in the cavity lining of the lung sections. The observed eryptosis was consistent with the in vitro results. Our results indicate that silver materialinduced cytotoxicity must be measured and compared using various methods.

Preparation of Lead-free Silver Paste with Nanoparticles for Electrode (나노입자를 첨가한 전극용 무연 silver 페이스트의 제조)

  • Park, Sung Hyun;Park, Keun Ju;Jang, Woo Yang;Lee, Jong Kook
    • Journal of the Korean Society for Heat Treatment
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    • v.19 no.4
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    • pp.219-224
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    • 2006
  • Silver paste with low sintered temperature has been developed in order to apply electronic parts, such as bus electrode, address electrode in PDP (Plasma Display Panel) with large screen area. In this study, nano-sized silver particles with 10-30 nm were synthesized from silver nitrate ($AgNO_3$) solution by chemical reduction method and silver paste with low sintered temperature was prepared by mixing silver nanoparticles, conventional silver powder with the particle size 1.6 um and Pb-free frit. Conductive thick film from silver paste was fabricated by screen printing on alumina substrate. After firing at $540^{\circ}C$, the cross section and surface morphology of the thick films were analyzed by FE-SEM. Also, the sheet resistivity of the fired thick films was measured using the four-point technique.

Study on the Diameter-Controlled Synthesis of Silver Nanofibers and Their Application to Transparent Conductive Electrodes (은 나노섬유의 직경제어 합성 및 투명전극 응용 연구)

  • Lee, Young-In
    • Korean Journal of Materials Research
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    • v.25 no.10
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    • pp.537-542
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    • 2015
  • One-dimensional (1D) silver nanostructures, which possess the highest conductivity among all room-temperature materials, moderate flexibility and high transmittance, are one of the most promising candidate materials to replace conventional indium tin oxide transparent electrodes. However, the short length and large diameter of 1D silver nanostructures cause a substantial decrease in the optical transparency or an increase in the sheet resistance. In this work, ultra-long silver nanofiber networks were synthesized with a low-cost and scalable electrospinning process, and the diameter of the nanofibers were finetuned to achieve a higher aspect ratio. The decrease in the diameter of the nanofibers resulted in a higher optical transparency at a lower sheet resistance: 87 % at $300{\Omega}/sq$, respectively. It is expected that an electrospun silver nanofiber based transparent electrode can be used as a key component in various optoelectronic applications.

Effect of ICCP Potential with Electrolyte on Corrosion and Discolor of Silver (은의 부식 및 변식에 미치는 전해질 용액에 따른 ICCP 전압의 영향)

  • Shin, Byung-Hyun;Kim, Do-Hyung;Chung, Won-Sub
    • Journal of Surface Science and Engineering
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    • v.53 no.5
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    • pp.207-212
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    • 2020
  • Silver is an inexpensive precious metal and is used in various jewelry in Asia. Although silver has high potential, it has corrosion resistance that is vulnerable to boiling sulfuric acid and nitric acid. So, silver research is needed to prevent the corrosion with environment. But silver corrosion is not studied. sulfuric acid make the uniform corrosion and chloride ion make the pitting corrosion. ICCP inhibits the corrosion because it offset electrons. This study used a potential from - 4 V to 4 V to check the effect of potential. Corrosion rate is lowet at -1 V.

Fabrication of Conductive Pastes for Induction Cookware with the Variation of the Contents of Silver Powder and Glass Frit (인덕션 조리용기용 도전성 Paste의 Silver 및 Glass Frit 함량 변화에 따른 미세구조 및 전기적 특성 고찰)

  • Gu, Hyun Ho;Kim, Bong Ho;Yoon, Young Joon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.11
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    • pp.690-695
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    • 2016
  • Induction cooktop has a great attention due to its safety, quick heating and cleanness compared to gas oven. However, the materials for induction cookware is limited to steel or stainless-steel which has the magnetic property. Recently, it has been tried to apply various porcelain to induction cookware after printing the silver layer on the bottom of cookware plates and co-firing at high temperature. Glass frits are added in the silver paste to improve an adhesion force between porcelain materials containers and transferred silver layer. The hybrid silver pastes for induction cookware requires the proper electrical resistance and the thermal conductivity with base plates. After sintering process at $800^{\circ}C$, a part of melted glass migrated to the porcelain and the rest of the glass frit was exposed to the surface. It was confirmed that most of the glass frit formed an adhesion layer between the porcelain and transferred silver layer that enhances the adhesion force.

Influence of Glass-Frit Size on the Microstructural Evolution of Conductive Silver Paste (전도성 실버 페이스트의 미세구조 발달에 미치는 glass-frit 크기의 영향)

  • Han, Hyun Geun;Seo, Dong Seok;Lee, Jong Kook
    • Korean Journal of Metals and Materials
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    • v.46 no.8
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    • pp.516-523
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    • 2008
  • The effect of glass-frit size on microstructural evolution and electrical resistance of conductive silver paste was investigated. Silver paste was prepared by mixing 70 wt% commercial silver powder with $1.6{\mu}m$, 3 wt% Bi based glass-frit and 27 wt% organic vehicle. Two different sizes of glass-frit were obtained by ball-milling of commercial glass-frit ($3{\mu}m$) for 3 and 5 days, which had an average particle size of 1.0 and $0.5{\mu}m$. The smaller glass-frit was melt at low sintered temperature and rapidly spread between the silver particles, which is induced the dense networking among silver particles and strong adhesiveness to $Al_2O_3$ substrate. The silver film with smaller glass-frit sintered at $500^{\circ}C$ showed the small pore size and low porosity resulting in low electrical resistivity of $4{\mu}{\Omega}cm$.

Controlling Size and Distribution of Silver Nanoparticles Generated in Inorganic Silica Nanofibers Using Poly(vinyl pyrrolidone)

  • Min, Kyung-Dan;Park, Won-Ho;Youk, Ji-Ho;Kwark, Young-Je
    • Macromolecular Research
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    • v.16 no.7
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    • pp.626-630
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    • 2008
  • Poly(vinyl pyrrolidone) was used successfully to control the size and distribution of silver nanoparticles generated on inorganic silica nanofibers. The inorganic nanofibers were electro spun using sol-gel chemistry of silicates, and the diameter of the prepared nanofibers was unaffected by adding up to 7% of poly(vinyl pyrrolidone). The silver ions, in the form of silver nitrate, were introduced into the silica nanofibers and reduced to metallic silver by ultraviolet irradiation with a subsequent thermal treatment. The size of the generated silver particles was decreased dramatically by adding poly(vinyl pyrrolidone). The size of the silver nanoparticles was 73 nm when no poly(vinyl pyrrolidone) was added but 23 nm with the addition of only 1% of poly(vinyl pyrrolidone). The extent of reduction could be checked by determining the concentration of silver ions leached into water from the silica nanofibers. After thermal treatment of the silica nanofibers, more than 99% of the silver remained in the nanofibers, indicating almost complete reduction of the silver ions to silver metal.