• Title/Summary/Keyword: Silver Engineering Technology

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Inactivation of S. epidermidis, B. subtilis, and E. coli Bacteria Bioaerosols Deposited on a Filter Utilizing Airborne Silver Nanoparticles

  • Lee, Byung-Uk;Yun, Sun-Hwa;Ji, Jun-Ho;Bae, Gwi-Nam
    • Journal of Microbiology and Biotechnology
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    • v.18 no.1
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    • pp.176-182
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    • 2008
  • In the present study, a control methodology utilizing airborne silver nanoparticles is suggested and tested with respect to its potential to control Gram-positive Staphylococcus epidermidis and Bacillus subtilis, and Gram-negative Escherichia coli bacteria bioaerosols deposited on filters. As it is known that the Gram-negative bacteria are sensitive to airflow exposure, the main focus of this study for testing the airborne silver nanoparticles effect was the Gram-positive Staphylococcus epidermidis and Bacillus subtilis bacteria bioaerosols whereas Escherichia coli bioaerosols were utilized for comparison. Airborne bacteria and airborne silver nanoparticles were quantitatively generated in an experimental system. Bioaerosols deposited on the filter were exposed to airborne silver nanoparticles. The physical and biological properties of the airborne bacteria and airborne silver nanoparticles were measured via aerosol measurement devices. From the experimental results, it was demonstrated that this method utilizing airborne silver nanoparticles offers potential as a bioaerosol control methodology.

Study of Antimicrobial Properties for Silver/Celite Composites (은/셀라이트 복합체의 항균특성에 관한 연구)

  • Lee, Chul-Jae;Kim, Byung-So
    • Applied Chemistry for Engineering
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    • v.20 no.6
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    • pp.696-699
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    • 2009
  • In present work, the antimicrobial effect of silver-nanoparticles/celite (SN/C) and silver carbonate/celite (SC/C) composites on Escherichia coli (E. coli) by use of silver nanoparticles and silver carbonate has been studied. Characteristics of the SN/C and SC/C composites were identified by scanning electron microscopy (SEM), X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS). SN/C and SC/C composites showed antimicrobial activity and the minimum inhibitory concentration of E. coli were 0.541, 0.344 ppm and the complete sterilizing concentration for the test organism were 1.427, 1.623 ppm. From the results we identified that SN/C and SC/C composites have antimicrobial activity to E. coli.

Influence of Cation Part of Ionic Liquids on Silver Particle Structure (이온성액체의 양이온이 은 입자 구조 형성에 미치는 영향)

  • Yun, Mi Hee;Yoo, Kye Sang
    • Applied Chemistry for Engineering
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    • v.27 no.5
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    • pp.551-554
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    • 2016
  • Silver particles were synthesized by chemical reduction with ionic liquids. Structure of silver particles were significantly affected by the cation parts of the ionic liquids. With increasing the length of the cation part, the smaller silver particles were formed regardless of the anion type. This is mainly attributed to the different stability of the ionic liquid structure formed by physical bond between cation parts. Among seven ionic liquids, [Omim][$PF_6$] was the most effective for synthesizing silver particles.

Statistical Analysis for Silver Nanoparticle Synthesis Using Ionic Liquid (이온성액체 기반 은 나노입자 합성을 위한 통계적 실험 분석)

  • Lee, Kil Woo;Yoo, Kye Sang
    • Applied Chemistry for Engineering
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    • v.29 no.1
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    • pp.77-80
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    • 2018
  • Silver nanoparticles with various sizes were synthesized using ionic liquids. In order to conduct more efficient research, experimental methods and results were analyzed statistically. First, effects of five different parameters including the reaction time, temperature, NaOH concentration, reducing agent and ionic liquid amount on the size of silver particles were investigated. As a result, the effects of time and temperature were negligible. The experimental conditions for the other three factors were then statistically constructed. From XRD analyses, the particles synthesized under all conditions had a pure silver crystal structure. Sizes of the synthesized silver particles were also analyzed by HR-SEM. In the three synthetic conditions, NaOH concentration had the greatest influence on determining the size of silver particles and the reducing agent concentration was relatively minute. Synthesis conditions of silver particles with various sizes were presented by using statistical methods with respect to NaOH and ionic liquids. In addition, the sizes of silver particles according to three experimental conditions were derived by the mixture method.

SERS Study of Quinoline Using the Silver Surface (Silver Surface를 이용한 Quinoline의 SERS 연구)

  • Lee, Chul-Jae;Jung, Maeng-Joon;Kim, Dong-Yeub
    • Journal of the Korean Society of Industry Convergence
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    • v.14 no.3
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    • pp.101-104
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    • 2011
  • In this study, the experiments for surface enhancement of silver surfaces were done, where we checked the characteristics of silver surfaces made by Tollen's method. The surface enhancement of Quinoline was analyzed by three kind of silver mirror substrates. The assignments of the vibrational bands shown in SERS spectra are given based on both literature and the semi-empirical calculations at the PM3 methods. Finally, we deduced that the adsorption orientation of quinoline was little tilted flat to the silver mirror surfaces by using of the surface selection rules.

SERS Study of Bromothymol Blue Using the Silver Mirror substrate (Silver Mirror Substrate를 이용한 Bromothymol Blue의 SERS 연구)

  • Lee, Chul-Jae;Jung, Maeng-Joon;Kim, Dong-Yeub
    • Journal of the Korean Society of Industry Convergence
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    • v.15 no.2
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    • pp.43-47
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    • 2012
  • In this study, the experiments for surface enhancement of silver mirror substrate were done, where we checked the characteristics of silver mirror substrate made by Tollen's method. The surface enhancement of Bromothymol blue was analyzed by three kind of silver mirror substrates. The assignments of the vibrational bands shown in SERS spectra are given based on both literature and the semi-empirical calculations at the PM3 methods. Finally, we deduced that the adsorption orientation of bromothymol blue was little tilted flat to the silver mirror surfaces by using of the surface selection rules.

SERS Study of Eriochrome Black T Using the Silver Mirror Substrates (Silver Mirror Substrate를 이용한 Eriochrome Black T의 SERS 연구)

  • Lee, Chul-Jae;Jung, Maeng-Joon;Kim, Dong-Yeub
    • Journal of the Korean Society of Industry Convergence
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    • v.14 no.1
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    • pp.23-27
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    • 2011
  • In this study, the experiments for surface enhancement of silver mirror substrates were done, where we checked the characteristics of silver mirror substrate made by Tollen's method. The surface enhancement of Eriochrome Black T(EBT) was analyzed by silver mirror substrates. We observed the SERS spectra of EBT. The assignments of the vibrational bands shown in SERS spectra are given based on both literature and the semi-empirical calculations at the PM3 methods. Finally, we deduced that the adsorption orientation of EBT was little tilted perpendicular to the silver mirror surfaces by using of the surface selection rules.

Effect of the Oxide Glass on the Metal Sintering Behavior in Silver Thick-Film System

  • Chung Young Sir;Kim Ho-Gi
    • Proceedings of the Korean Ceranic Society Conference
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    • 1986.12a
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    • pp.259-267
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    • 1986
  • The sintering behavior of silver-oxide glass composite thick-film has been studied with varing glass content. It is shown that during heat treatment glass became liquid phase to deeply affect the microstructure development of the silver particles and to control the physical properties of the thick-films. As glass content increased, the initial repacking of silver particles took place rapidly but the homogeneities of the microstructure showed different features. When the glass content was over some range, the silver particles exuded glass to decrease net energy and glass formed liquid pools separated from the solid skeletons. Finally the relations between the microstructures and electrical properties of the thick-film were discussed.

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Nanocarbon/silver Nanowire Hybrid Flexible Transparent Conducting Film Technology (탄소나노튜브와 은나노와이어 복합 유연투명전극 필름 기술)

  • Han, Joong Tark
    • Journal of Surface Science and Engineering
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    • v.49 no.4
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    • pp.323-330
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    • 2016
  • The flexible transparent conducting films (TCFs) are required to realize flexible optoelectronic devices. 1D nanomaterials such as carbon nanotubes (CNTs), metal nanowires are good candidates to replace indium tin oxide that is currently used to fabricate transparent electrode. Particularly, silver nanowires are used to produce flexible TCFs. In this review, we introduce TCF technologies based on silver nanowires/CNTs hybrid structures. CNTs can compromise drawbacks of silver nanowires for applications in high performance TCFs for optoelectronic devices.

Joule Heating of Metallic Nanowire Random Network for Transparent Heater Applications

  • Pichitpajongkit, Aekachan;Eom, Hyeonjin;Park, Inkyu
    • Journal of Sensor Science and Technology
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    • v.29 no.4
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    • pp.227-231
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    • 2020
  • Silver nanowire random networks are promising candidates for replacing indium tin oxide (ITO) as transparent and conductive electrodes. They can also be used as transparent heating films with self-cleaning and defogging properties. By virtue of the Joule heating effect, silver nanowire random networks can be heated when voltage bias is applied; however, they are unsuitable for long-term use. In this work, we study the Joule heating of silver nanowire random networks embedded in polymers. Silver nanowire random networks embedded in polymers exhibit breakdown under the application of electric current. Their surface morphological changes indicate that nanoparticle formation may be the main cause of this electrical breakdown. Numerical analyses are used to investigate the temperatures of the silver nanowire and substrate.