• 반도체디스플레이기술학회지
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• 제11권2호
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• pp.23-26
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• 2012

The monodispersed polystyrene spheres were prepared by emulsion polymerization in aqueous alcohol system. They coated with silver by reduction of silver ion percolated on the surface of them. The spherical hollow type silver has been prepared by dissolving polystyrene with toluene. Epoxy resin compositions with spherical hollow type silver were manufactured, which were composed of a bisphenol F type epoxy resin (RE-304S), amine type hardener (Kayahard AA), and 1-benzyl 2-methyl imidazole (1B2MI) as catalyst. The electrical conductivity with silver content ratio were investigated after cure, the percolation threshold weight ratio for conductance in this epoxy resin system was obtained above the 70 wt% of silver.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.390-391
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• 2007

LED Packaging 과정 중 Die bond 재료로 Silver epoxy를 사용하여 Packaging 한 후 T3Ster 장비로 열 저항 값(Rth)을 측정하였다. Silver epoxy 의 접착 두께를 조절하여 열 저항 값을 측정하였고, 열전도도 값이 다른 Silver epoxy를 사용하여 열 저항 값을 측정하였다. Silver epoxy 접착 두께가 충분하여 Chip 전면에 고루 분포되었을 경우 그렇지 않은 경우보다 평균 4.8K/W 낮은 13.23K/W의 열 저항 값을 나타내었고, 열전도도가 높은 Silver epoxy 일수록 열전도도가 낮은 재료보다 평균 4.1K/W 낮은 12K/W의 열 저항 값을 나타내었다.

• Advances in nano research
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• 제4권4호
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• pp.281-294
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• 2016

The advantages of nano-scale materials (size 1-99 nm in at least in one dimension) could be realized with their potential applications in diversified avenues. Herein, we report for the first time on the successful synthesis of homogeneous epoxy coatings containing phytogenic silver nanoparticles (Ag) on PVC and glass substrates by room-temperature curing of fully mixed epoxy slurry diluted by acetone. Alstonia scholaris bark extract was used to reduce and stabilize the silver ions. The surface morphology and mechanical properties of these coatings were characterized using the techniques like, UV-Vis (UV-Visible) spectrophotometry, X-ray diffraction (XRD), Fourier transform infrared spectrophotometry (FT-IR), Epifluorescence microscopy and scanning electron microscopy (SEM). The effect of incorporating Ag nanoparticles on the biofilm (scale) resistant epoxy-coated PVC was investigated by total viable counts ($CFU/cm^2$) from epoxy coating from (Initial) $1^{st}$ day to $25^{th}$ days. The phytogenic Ag nanoparticles were found to be significantly improving the microstructure of the coating matrix and thus enhanced the anti-biofilm performance of the epoxy coating. In addition, the antimicrobial mechanism of Ag nanoparticles played an important role in improving the anti-biofilm performance of these epoxy coatings.

• Advances in aircraft and spacecraft science
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• 제4권6호
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• pp.729-744
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• 2017

This investigation highlights rationale of electrically conductive nano adhesives for its essential application for Electromagnetic Interference (EMI) Shielding in satellites and Lightning Strike Protection in aircrafts. Carbon Nano Fibres (CNF) were functionalized by electroless process using Tollen's reagent and by Plasma Enhanced Chemical Vapour Deposition (PECVD) process by depositing silver on CNF. Different weight percentage of CNF and silver coated CNF were reinforced into the epoxy resin hardener system. Scanning Electron Microscopy (SEM) micrographs clearly show the presence of CNF in the epoxy matrix, thus giving enough evidence to show that dispersion is uniform. Transmission Electron Microscopy (TEM) studies reveal that there is uniform deposition of silver on CNF resulting in significant improvement in interfacial adhesion with epoxy matrix. There is a considerable increase in thermal stability of the conductive nano adhesive demonstrated by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Four probe conductivity meters clearly shows a substantial increase in the electrical conductivity of silver coated CNF-epoxy composite compared to non-coated CNF-epoxy composite. Tensile test results clearly show that there is a significant increase in the tensile strength of silver coated CNF-composites compared to non-coated CNF-epoxy composites. Consequently, this technology is highly desirable for satellites and EMI Shielding and will open a new dimension in space research.

• 비파괴검사학회지
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• 제33권5호
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• pp.459-464
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• 2013

Structures can be evaluated their health status by allowable loading criteria. These criteria can be determined by the maximum strain. Therefore, in order to detect this maximum strain of structures, fiber optic Bragg grating(FBG) sensor probes are newly designed and fabricated to perform the memorizing detection even if the sensor system is on-and-off. The probe is constructed with an FBG optical fiber embedded in silver epoxy. When the load is applied and removed on the structure, the residual strain remains in the silver epoxy to memorize the maximum strain effect. In this study, a commercial Al-foil bonded FBG sensor probe was tested to investigate the detection feasibility at first. FBG sensor probes with silver epoxy were fabricated as three different sizes. The detection feasibility of maximum strain was studied by doing the tensile tests of CFRP specimens bonded with these FBG sensor probes. It was investigated the sensitivity coefficient defined as the maximum strain divided by the residual strain. The highest sensitivity was 0.078 of the thin probe having the thickness of 2 mm.

• Journal of Electrical Engineering and Technology
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• 제8권3호
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• pp.603-609
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• 2013

In this paper, we describe the analysis of inkjet-printed silver (Ag) patterns on epoxy-coated substrates according to several reliability evaluation test method guidelines for conventional printed circuit boards (PCB). To prepare patterns for the reliability analysis, various regular test patterns were created by Ag inkjet printing on flame retardant 4 (FR4) and polyimide (PI) substrates coated with epoxy for each test method. We coated the substrates with an epoxy primer layer to control the surface energy during printing of the patterns. The contact angle of the ink to the coated epoxy primer was $69^{\circ}$, and its surface energy was 18.6 $mJ/m^2$. Also, the substrate temperature was set at $70^{\circ}C$. We were able to obtain continuous line patterns by inkjet printing with a droplet spacing of $60{\mu}m$. The reliability evaluation tests included the dielectric withstanding voltage, adhesive strength, thermal shock, pressure cooker, bending, uniformity of line-width and spacing, and high-frequency transmission loss tests.

• 대한화학회지
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• 제20권4호
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• pp.280-289
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• 1976

$Ag_2Se$ 전극을 제조하고 은이온에 대한 지시전극으로서의 성질을 조사하였다. Epoxy 수지를 Ag_2Se 전극의 binder로서, Silver paste를 감응막과 은판의 접착제로서 사용하였다. 감응막은 10ton/$cm^2$로 가압성형 한다음 질소분위기에서 200${\sim}$$500^{\circ}C$로 sintering한 후 전극을 제조한 결과sintering 하지않은 전극보다 감응성이 우수하고 견고하였다. 또한 $Ag_2Se$전극보다 감응성이 우수하였다. 은이온농도의 변화에 따르는 감응도는 10-6M까지 직선관계를 유지하였다. 대부분의 중금속 이온은 방해하지 않으나 수은(II) 이온이 크게 방해를 하였으며 음이온인 halide, cyanide, thiocyanate 이온의 방해는 더욱 심하였다. 반면 이전극은 halide 이온 정량시 전위차적정법으로 사용할 수 있음을 알았다.

• 한국염색가공학회지
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• 제28권2호
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• pp.70-76
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• 2016

Silver nanoparticles(AgNPs) were attached to wool fibers using glycidyltrimethylammonium chloride(GTAC), which is a type of quaternary ammonium salt. GTAC, which contains an epoxy functional group that, under high temperatures, generates a ring-opening reaction with wool fibers, which contain the amine group. Then, the AgNPs are attached to the surface of the GTAC-treated wool fibers by treatment with a silver colloidal solution. The process involves the following procedures: (1) The wool fibers are immersed in the GTAC solution, followed by pre-drying at $80^{\circ}C$ and curing at $180^{\circ}C$ to induce an alteration in the chemical structure; and (2) The wool fibers treated with GTAC are immersed in the silver colloid at $40^{\circ}C$ for 120 min to chemically induce a strong attachment of the AgNPs to the wool fibers. Scanning electron microscopy was used to analyze the influence of the concentrations of GTAC and the silver colloid, as well as the influence of the applied temperature of the silver colloid on the wool fibers, and the influence of the morphological changes in the wool fiber surfaces. As a result, the enhanced concentrations of GTAC and the silver colloid together with an elevated applied temperature of silver colloid have a tendency to increase in Ag atomic%.

• Korean Chemical Engineering Research
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• 제55권3호
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• pp.426-429
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• 2017

본 연구에서는 은나노입자 및 보론나이트라이드의 혼합이 열전도도 및 전기전도도에 미치는 효과에 대해 고찰하였다. 에폭시/보론나이트라이드 복합체의 경우 열전도도가 보론나이트라이드의 함량에 비례하여 증가하였으며 에폭시/은나노입자의 경우는 열전도도가 크게 변화 없었으며 전기전도도는 20 vol%에서 퍼콜레이션 현상을 보여주었다. 퍼콜레이션 함량 이하에서 은나노입자를 고정시키고 보론나이트라이드를 첨가하여 조사한 결과 전기전도도 및 열전도도가 크게 향상됨을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.483-488
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• 2012

We successfully decorated multi-wall carbon nanotubes (MWNTs) with silver by reacting Ag-NPs with thiolfunctionalized MWNT-SH. Ag alkylcarbamate complex was used as an Ag precursor. Uniform Ag-NPs (5-10 nm) were effectively prepared by microwaving within 60 s using 1-amino-4-methylpiperazine (AMP), which acts as a reaction medium, reducing agent, and stabilizer. The MWNTs were functionalized with 2-aminoethanethiol. Exploiting the chemical affinity between thiol and Ag-NPs, Ag-MWNT nanohybrids were obtained by spontaneous chemical adsorption of MWNT-SH to Ag through Ag-S bonds. The Ag-S-MWNTs were characterized by TGA, XRD, and TEM to confirm that Ag-NPs were uniformly decorated onto the MWNTs. The Ag-S-MWNTs were then employed as conducting filler in epoxy resin to fabricate electrically conducting polymer composites. The electrical properties of the composites were measured and compared with that containing MWNT-SH. The electrical conductivity of composites containing 0.4 wt % Ag-S-MWNT was four orders of magnitude higher than those containing same content of MWNT-SH, confirming Ag-S-MWNT as an effective conducting filler.