• Title/Summary/Keyword: Ag particles

Search Result 269, Processing Time 0.026 seconds

Chemical Composition and Sources of Atmospheric Particulates Collected on the West Coast of Korea (서해안 대가 분진의 화학 조성 및 기원에 대한 연구 (1))

  • 최만식;조성록;이동수
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.5 no.2
    • /
    • pp.72-83
    • /
    • 1989
  • Twenty-five atmospheric particulates were collected using a high volume aerosol sampler from Septermber to December, 1988 on a site located on the West coast of Korea and analysed for twelve elements (Na, Mg, Al, Mn, Fe, Cu, Co, Ni, Zn, Ag, Cd, and Pb) by AAS. The particles being mainly crustal minerals, large quantity of spherical fly ashes were also observed. In order to identify the origin of trace metals in atmospheric particulates, enrichment factor, interelemental correlation and factor analysis were performed. Based upon these analysis, the twelve elements can be classified into three groups; the elements dominantly present in soil particles (Al, Mn, Fe, Co, and Ni), those in sea salt aerosols (Na and Mg), and those in air pollution-derived particles (Cu, Cd, Pb, Ag and Zn).

  • PDF

The Electrochemical properties of Lithium ion Secondary Battery using Ag-deposited graphite anode (은 담지한 혹연을 부극 활물질로 이용한 Li ion 2차전지의 전기화학적 특성 연구)

  • 김상필;조정수;박정후;윤문수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 1998.06a
    • /
    • pp.387-390
    • /
    • 1998
  • New Ag-deposited graphite anodes were developed using wet chemical reduction methods for depositing Ag metal onto graphite particles. In this paper, we investigated X-ray diffraction pattern and charge-discharge behavior for Ag-deposited graphite anode. The Lithium ion cello using Ag-deposited graphite anode showed a high average discharge voltage of 3.6∼3.W and a excellent cycle ability than that of conventional graphite. Little capacity loss in this battery may be due to the highly durable Ag-deposited graphite anodes.

  • PDF

SERS on Silver Formed in Anodic Aluminum Oxide Nanotemplates

  • 주영;서정상
    • Bulletin of the Korean Chemical Society
    • /
    • v.16 no.9
    • /
    • pp.808-810
    • /
    • 1995
  • A strong SERS effect has been observed on silver surfaces which were prepared by Ag deposition in anodic aluminum oxide nanotemplates and subsequent partial removal of the oxide layers. The advantage of these surfaces for SERS studies is that the controlled size and dispersion of Ag particles can be achieved.

Ag-Cu Powders Prepared by Electrical Wire Explosion of Cu-plated Ag Wires (동도금한 은선재의 전기선폭발에 의해 제조한 Ag-Cu분말)

  • Kim, Won-Baek;Park, Je-Shin;Suh, Chang-Youl
    • Journal of Powder Materials
    • /
    • v.14 no.5
    • /
    • pp.320-326
    • /
    • 2007
  • Ag-Cu alloy nano powders were fabricated by the electrical explosion of Cu-plated Ag wires. Ag wires of 0.2mm diameter was electroplated to final diameter of 0.220 mm and 0.307 mm which correspond to Ag-27Cu and Ag-68Cu alloy. The explosion product consisted of equilibrium phases of ${\alpha}-Ag$ and ${\beta}$-Cu. The particle size of Ag-Cu nano powders were 44 nm and 70 nm for 0.220 mm and 0.307 mm wires, respectively. The Ag-Cu nano powders contained less Cu than average value due to higher sublimation energy compared to that of Ag. As a result, micron-sized spherical particles formed from liquid droplets contained higher Cu content.

Heterogeneous nucleations in the polyol process for the preparation of fine cobalt particles (미립 코발트분말 합성을 위한 polyol공정에서 비균질계 핵생성 반응)

  • 김동진;정헌생;우상덕;이재장;안종관
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.12 no.2
    • /
    • pp.73-79
    • /
    • 2002
  • The polyol process which applies to cobalt, nickel. copper and precious metals is a interesting and unexpected example of such a method for preparing uniform metal powders. The reaction proceeds via dissolution, and the polyol acts simultaneously as a solvent, a reducing agent, and to some extent a protective agent. Submicrometer uniform cobalt particles can be obtained by seeding the reactive medium ($AgNO_3$) to achieve a complete substitution of homogeneous by heterogeneous nucleation. By varying the number of nuclei it is possible to control to some extent the average particle size in the submicrometer (0.5$\mu$m) range.

Ag입자를 이용한 Carbon nanotube 투명 박막의 전도특성 변화에 대한 연구

  • Lee, Su-Min;Kim, Seon-Min;Sin, Gwon-U;Han, Jong-Hun
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2011.02a
    • /
    • pp.453-453
    • /
    • 2011
  • 탄소나노튜브(CNT)를 이용한 전도성 투명 박막은 기존의 산화인듐주석(ITO)보다 가공 공정이 매우 간단하고 제조비용이 저렴하여 다양한 제품에 적용시킬 수 있고, 다양한 기판에 형성시킬 수 있어 새로운 유형의 제품을 만들 수 있는 가능성이 있다. 본 연구에서는 CNT를 이용하여 만든 투명 박막의 전도특성을 높이기 위하여 기존의 CNT 박막에 금속 이온간의 산화-환원 반응을 이용하여 Tin(II) chloride와 silver nitrate로 Ag seed를 형성시켜 투명 전도막 효율 변화를 측정하였다.

  • PDF

Fabrication of Ag doped Hydroxyapatite and its Antimicrobial Effects with the Particle Size

  • Oh, Kyung-Sik;Kim, Kyung-Ja;Jeong, Young-Keun
    • Journal of Powder Materials
    • /
    • v.8 no.3
    • /
    • pp.192-196
    • /
    • 2001
  • Ag doped Hydroxyapatite powder in nano-scale was successfully synthesized either by co-precipitation or by ion exchange route. The fabricated powder was successfully dispersed through freeze drying due to the prevention of secondary particles. The antimicrobial effects of nano-HAp against E.coli was superior to micron ones not only in its strength but also in duration.

  • PDF

Extinction Coefficient of Ag Nanofluids Manufactured by Chemical Reduction Method (화학적 환원법으로 제작한 은나노유체의 흡광계수)

  • Lee, S.H.;Kim, H.J.;Choi, T.J.;Kim, S.B.;Kang, Y.J.;Kim, D.J.;Jang, S.P.
    • Journal of ILASS-Korea
    • /
    • v.20 no.1
    • /
    • pp.53-58
    • /
    • 2015
  • In this study, we prepare the Ag nanofluids synthesized by the chemical reduction method and measure the extinction coefficient of those nanofluids at a wavelength of 632.8 nm. The Ag nanofluids are synthesized by the chemical reduction method using silver nitrate ($AgNO_3$) and sodium borohydride ($NaBH_4$) in water and ethylene glycol (EG). For stable dispersion of Ag particles in the base liquids, polyvinyl pyrrolidone (PVP) is added as a surfactant. The extinction coefficient of manufactured Ag nanofluids is measured by an in-house developed measurement system at the wavelength of 632.8 nm. The results show that the extinction coefficient of water-based and EG-based Ag nanofluids is linearly increased with respect to the particle loadings. Moreover, it is shown that the extinction coefficient of EG-based Ag nanofludis is higher than that of water-based Ag nanofluids. Finally we compare the experimental results with both the Maxwell-Garnett model and Rayleigh scattering approximation model, and they demonstrate that the Rayleigh scattering approximation model is reasonably predict the extinction coefficient of Ag nanofluids using hydraulic diameter of silver nanoparticle.