• Title/Summary/Keyword: silver ion

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Construction of Carbon Paste Coated Wire Ion-Selective Electrode for Chloride and Its Application to Environmental Water Analysis

  • Yong-Kyun Lee;Soo Kil Rhim;Kyu-Ja Whang
    • Bulletin of the Korean Chemical Society
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    • v.10 no.6
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    • pp.485-488
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    • 1989
  • A carbon paste coated-wire ion-selective electrode for chloride (carbon chloride-CWE) was constructed using epoxy resin, ion-exchanger and carbon powder as a polymer membrane. Its utility, the composition of a polymer membrane, the response characteristics, and the selectivity were examined and applied to the environmental water analysis. The carbon chloride-CWE was prepared using a silver wire, which was covered with silver chloride and then coated with epoxy resin into which chloride ion-exchanger and carbon powder were previously incorporated in advance. The response of the carbon chloride-CWE was Nernstian for $1.0{\times}10^{-2}-2{\times}10^{-5}$ M chloride and the useful pH range from $10^{-2} M Cl- to 10^{-4} M Cl^-$ was 3.0-9.0. Furthermore, the selectivity of chloride over iodide, bromide, and cyanide was much improved compared with those for a solid state epoxy body chloride electrode and a liquid membrane chloride electrode. The carbon chloride-CWE was applied to determine Cl^-$ in tap and ground water. The obtained results were in good agreement with those by the established methods such as spectrophotometric or other chloride-selective electrode methods.

Antimicrobial Effects and Mechanism(s) of Silver Nanoparticle (은나노 입자의 항균작용과 작용기작)

  • Hwang, In-Sok;Cho, Jae-Yong;Hwang, Ji-Hong;Hwang, Bo-Mi;Choi, Hye-Min;Lee, June-Young;Lee, Dong-Gun
    • Microbiology and Biotechnology Letters
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    • v.39 no.1
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    • pp.1-8
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    • 2011
  • The antimicrobial effects of silver (Ag) ion or salts are well known. Recently, silver nanoparticle is attracting an interest in a wide variety of fields since it has been known to be safe and effective as an antimicrobial agent against a broad spectrum of microorganisms. Although silver nanoparticle has been applied to various kinds of products owing to its potent antimicrobial activity, the effects of silver nanoparticle on microorganisms and antimicrobial mechanism have not been revealed clearly. In this paper, we summarized the characteristics, antimicrobial activities and mechanisms, cytotoxicity and applicability of silver nanoparticle.

Silver recovery from photographic wastewater by electrowinning process with electrolyte recirculation (실제(實際) 사진폐액(寫眞廢液)의 순환(循環) 전해채취(電解採取) 공정(工程)에 의한 은(銀)의 환원(還元) 특성(特性))

  • Chung, Won-Ju;Kim, Dong-Su
    • Resources Recycling
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    • v.16 no.1 s.75
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    • pp.54-58
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    • 2007
  • In the continuous flow reductive treatment for recovery of silver from actual photographic wastewater, the effects of electrolysis time, applied potential, and the concentration of silver ion on the process have been examined. The efficiency of silver recovery for diluted photographic wastewater was increased with applied potential and reached its maximum at 6 V. However, the recovery of silver was shown to be decreased with potential above this. When the wastewater was undiluted, the efficiency of silver recovery was observed to rise as the applied potential became lower under the experimental conditions.

Characteristics of Silver Ion-Exchange and Methyl Iodide Adsorption at High Temperature Condition by Surface-Modified Natural Zeolite (표면개질 천연제올라이트를 이용한 은이온 교환 및 고온공정에서 메틸요오드 흡착특성)

  • Park, Geun Il;Cho, Il-Hoon;Kim, Kae-Nam;Lee, Min Ok;Yu, Jae-Hyung
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.10
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    • pp.1765-1775
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    • 2000
  • The removal of radioactive organic iodide generated from high temperature process in nuclear facility was generally performed by silver ion-exchanged synthetic zeolite (AgX). The purpose of this study is to obtain fundamental data for the substitution of natural zeolite(NZ) in stead of synthetic zeolite as supporter for the removal of methyl iodide in high temperature conditions. Therefore, NZ was modified with NaCl, $NaNO_3$ solution, and the analysis of the physical or surface characteristics through XRD, SEM-EDAX, and BET analysis was performed. In order to obtain the optimal surface-modification condition of NZ, adsorption capacities at $150^{\circ}C$ on surface-modified silver ion-exchanged NZ prepared with the variation of solution concentration were evaluated. The optimal condition of surface modification is that concentration of $NaNO_3$ and $AgNO_3$ are 1N and 1.2N, respectively(namely Ag-SMNZ). The adsorption isotherm of methyl iodide on Ag-SMNZ in a range of $100^{\circ}C$ to $300^{\circ}C$ was obtained, which is similar to that of 13X, and the maximum adsorption amount of Ag-SMNZ reached approximately 50% that of AgX. It would be evaluated that the adsorption capacity at $150{\sim}200^{\circ}C$ is relatively higher than other temperature, and the chemisorption between silver and iodide is attributed to a strong binding even after desorption test.

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Interconnecting Nanomaterials for Flexible Substrate and Direct Writing Process

  • Jwa, Yong-Ho
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2012.05a
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    • pp.58.1-58.1
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    • 2012
  • Direct write technologies provide flexible and economic means to manufacture low-cost large-area electronics. In this regard inkjet printing has frequently been used for the fabrication of electronic devices. Full advantage of this method, which is capable of reliable direct patterning with line and space dimensions in the 10 to 100 um regime, is only made with all-solution based processing. Among these printable electronic materials, silver and copper nanoparticles have been used as interconnecting materials. Specially, solutions of organic-encapsulated silver and copper nanoparticles may be printed and subsequently annealed to form low-resistance conductor patterns. In this talk, we describe novel processes for forming silver nanoplates and copper ion complex which have unique properties, and discuss the optimization of the printing/annealing processes to demonstrate plastic-compatible low-resistance conductors. By optimizing both the interconnecting materials and the surface treatments of substrate, it is possible to produce particles that anneal at low-temperatures (< $200^{\circ}C$) to form continuous films having low resistivity and appropriate work function for formation of rectifying contacts.

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Isolation of Pure $\alpha$-Linolenic Acid from Perilla Seed Oil (들깨유로부터 $\alpha$-Linolenic Acid의 순수분리)

  • 정보영;류수노;허한순
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.6
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    • pp.1028-1032
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    • 1997
  • Low-temperature crystallization method silver nitrate-impregnated silicic acid column chromatography were applied for the isolation of pure $\alpha$-linolenic acid(ALA) from perilla seed oil. ALA or 78% in purity(HALA; yield, 83%) was obtained from the fatty acid mixture(ALA, 65.7%) derived from perilla oil by the low-temperature crystallization method, when the mixture was frozen at -8$0^{\circ}C$ for 210min. ALA over 90% in purity(yield, 71%) was also obtained from HALA ethyl esters(ALA, 78%) by the silver nitrate-impregnated silicic acid column(100cm$\times$10cm, i.d.) chromatography. In addition, the silver nitrate-impregnated silicic acid could be semipermanently used for isolation of ALA, because $Ag^{+}$ ion was not dissociated from the stationary phase.

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Characteristics of silver ion-exchanged glass waveguides at 633nm and $1.5{\mu}m$ (은 이온 교환법으로 만든 유리 도자로의 633nm와 $1.5{\mu}m$에서의 특성 연구)

  • 유건호
    • Korean Journal of Optics and Photonics
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    • v.3 no.3
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    • pp.198-202
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    • 1992
  • Silver ion-exchanged glass waveguide with its large surface index difference and shallow depth is suitable to be used for the hybrid integration of semiconductor device and glass waveguide using the semiconductor film grafting technique. We report characteristics of the planar and channel glass waveguides exchanged in the diluted silver nitrate melt in the visible and infrared spectral region. Especially, we determined the fabrication parameters for single-mode channel waveguide at 1.5.$\mu$m, an important wavelength in the optical communication. Directional couplers with several different configurations were fabricated, and their 3 dB coupling length was determined as a function of wavelenGh and polarization.

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Recovery of Silver from Artificial Photographic Wastewater by Continuous Flow Electrolytic Process (순환공정법(循環工程法)을 적용(適用)한 인공(人工) 사진폐액(寫眞廢液)으로부터의 전해채취(電解採取)에 의한 은(銀)의 회수(回收))

  • Chung, Won-Ju;Kim, Dong-Su
    • Resources Recycling
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    • v.16 no.1 s.75
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    • pp.68-72
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    • 2007
  • The influences of reduction time, potential difference and ionic concentration flow rate have been investigated on the electrolytic recovery of silver from artificial photographic wastewater in continuous flow reactor system. As the initial concentration of silver ion and applied potential were increased, the amount of silver recovered was observed to be raised. Also, the electrolytically recovered material from artificial wastewater was proved to be pure silver based on the qualitative analyses by EPMA and XRD.

Desorption and Regeneration Characteristics for Previously Adsorbed Silver Ions onto Crab Shells Using Nitric Acid (질산을 이용한 게껍질에 흡착된 은 이온의 탈착 및 재생 특성)

  • Jeon, Choong
    • Journal of the Korea Organic Resources Recycling Association
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    • v.21 no.4
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    • pp.82-87
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    • 2013
  • A study on desorption and regeneration characteristics for silver ions adsorbed onto crab shells was carried out by means of Nitric acid soultion which was selected as the best desorbing agent. Desorption efficiency for silver ions was the highest as about 96% at the 1.0M of Nitric acid concentration. Also, silver ions was almost desorbed below 1.0 of S/L(mg/mL) ratio which is defined as the ratio of adding amount of adsorbent and volume of desorbing agent and most of desorption process was completed within 60min. And removal efficiency of reused crab shells for silver ions was maintained as about 92% until the 2nd cycle.

Study of Ag-Doped Bioactive Ceramic Composites (은이 첨가된 생체 활성 세라믹 복합체 연구)

  • Nam, Ki-Young
    • Journal of the Korean Chemical Society
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    • v.53 no.6
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    • pp.761-764
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    • 2009
  • Ag-Doped bioactive ceramic composites were prepared by colloidal silver solution. The physical properties of colloidal silver solution and Ag-Doped bioactive ceramic composites were characterized by Scanning electron microscopy(SEM), X-Ray Diffractometer(XRD) and Raman spectrophotometer respectively. According to XRD, we have identified that the chloride ion was chemically attached silver nano particles. SEM studies showed that silver chloride phases were homogeneously distributed on the Ag-Doped bioactive ceramic composites surface. Finally, we concluded that the silver chloride phase on the Ag-Doped bioactive ceramic composites surface was strongly prevent formation of Ag-hydroxyapatite.