• YAKHAK HOEJI
• /
• v.56 no.2
• /
• pp.74-79
• /
• 2012

Citrate-capped silver nanoparticles (AgNPs) are widely used in industry, consumer products and medical appliances. However, information on the toxicity, environmental fate and toxicokinetics are not enough. In this study, stability of citrate-capped AgNPs was investigated using different types of isotonic solution, which is important in the toxicokinetic study by the exposure route of intravenous injection. Size, morphology, zeta potential and ion formation were investigated in isotonic solutions for the physico-chemical characterization of AgNPs. Aggregation and precipitation of AgNPs were observed in saline or phosphate-buffered saline while they were stable without precipitation in 2% glycerol of isotonic solution. The average size of AgNPs in 2% glycerol was 6~10 nm, which was almost same as that in water-based suspension of AgNPs. Zeta potential was ranged from -30 mV to -60 mV, which was in the range of original stock AgNPs. The stability was maintained during the whole experimental period of 48 hours. Furthermore, the stability was not changed in different temperature (10~36$^{\circ}C$) and at different concentrations (10~1,000 ppm). The osmolarity of the AgNPs suspension was $299{\pm}1$ mOsm/kg which was in isotonic range. These data suggest that AgNPs in 2% glycerol solution can be used for the preparations of intravenous injection for toxicokinetic study without undesired disturbance of blood isotonicity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.20 no.12
• /
• pp.1022-1026
• /
• 2007

We have demonstrated new functionalities of Ag doped chalcogenide glasses based on their capabilities as solid electrolytes. Formation of such amorphous systems by the introduction of silver via photo-induced diffusion in thin chalcogenide films is considered. The influence of silver on the properties of the newly formed materials is regarded in terms of diffusion kinetics and Ag saturation is related to the composition of the hosting material. Silver saturated chalcogenide glasses have been used in the formation of solid electrolyte which is the active medium in programmable metallization cell (PMC) devices. In this paper, we investigated electrical and optical properties of Ag-doped chalcogenide thin film on changed thickness of Ag and chalcogenide thin films, which is concerned at Ag-doping effect of PMC cell. As a result, when thickness of Ag and chalcogenide thin film was 30 nm and 50 nm respectively, device have excellent characteristics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.24-24
• /
• 2007

We have demonstrated new functionalities of Ag doped chalcogenide glasses based on their capabilities as solid electrolytes. Formation of such amorphous systems by the introduction of silver via photo-induced diffusion in thin chalcogenide films is considered. The influence of silver on the properties of the newly formed materials is regarded in terms of diffusion kinetics and Ag saturation is related to the composition of the hosting material. Silver saturated chalcogenide glasses have been used in the formation of solid electrolyte which is the active medium in programmable metallization cell (PMC) devices. In this paper, we investigated electrical and optical properties of Ag-doped chalcogenide thin film on changed thickness of Ag and chalcogenide thin films, which is concerned at Ag-doping effect of PMC cell. As a result, when thickness of Ag and chalcogenide thin film was 30nm and 50nm respectively, device have excellent characteristics.

• Journal of the Semiconductor & Display Technology
• /
• v.16 no.3
• /
• pp.31-35
• /
• 2017

We have fabricated flexible and stretchable pressure sensors using silver nanowires (AgNWs) and analyzed their electric responses. AgNWs are spray coated directly onto uncured polydimethylsiloxane (PDMS) such that AgNWs penetrate into the uncured PDMS, enhancing the adhesion properties of AgNWs. However, the single-layered AgNW sensor exhibits unstable electric response and low pressure sensitivity. To tackle it, we have coated a conductive polymer, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) onto the AgNW layer. Such a hybrid bilayer sensor ensures a stable electric response because the over-coating layer of PEDOT:PSS effectively suppresses the protrusion of AgNWs from PDMS during release. To enhance the sensitivity further, we have also fabricated a stacked bilayer AgNW sensor. However, its electric response varies depending sensitively on the initial overlap pressure.

• Journal of the Microelectronics and Packaging Society
• /
• v.23 no.4
• /
• pp.93-99
• /
• 2016

In this paper, we investigated the mechanical and electrical reliability of silver nanowire (AgNW) films. In particular, the durability and reliability of AgNW films were studied when the AgNW film was subjected to the bending deformation under current flow. The electrical durability of AgNW was evaluated by observing changes in heat generation and current density occurring in AgNW through voltage and current tests. The AgNW film showed a constant resistance change up to a bending radius of 2 mm and 200,000 cycles in the bending fatigue tests. The over-coating layer has an effect of improving the durability of the AgNW film. In the case of AgNW with the over-coating layer, heat was uniformly dissipated on the surface of AgNW film, whereas in the case of AgNW film without the over-coating layer, heat was generated locally. In the bending test under the current flow, the current density of the AgNW film was continuously decreased up to 52.4%. During bending, the AgNW was deformed due to mechanical deformation such as tensile, bending and sliding of the AgNW, consequently contact resistance of the AgNW was increased, leading to a electrical breakdown of AgNW by Joule heating. It was found that the application of the over-coating layer can improve the electrical and mechanical reliability of the AgNW film.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.30 no.9
• /
• pp.572-576
• /
• 2017

A hybrid transparent electrode was fabricated with graphene and silver nanowires (Ag NWs). Three different processes were used to fabricate the hybrid electrode. Measurements of the sheet resistances, transmittances, and surface roughnesses of the hybrid electrodes were used to identify the optimal fabrication process. The surface roughness of the hybrid electrodes with Ag NWs embedded in a transparent polymer matrix was significantly lower than that of the other hybrid electrodes. A hybrid electrode fabricated by transferring graphene onto Ag NWs after spin-coating the Ag NWs onto the substrate showed the lowest sheet resistance. The transmittance of the hybrid electrodes was comparable to that of Ag NW electrodes.

• Journal of Electrical Engineering and Technology
• /
• v.12 no.1
• /
• pp.284-287
• /
• 2017

This paper introduces liquid crystal (LC) alignment and its electro-optical properties in the LC cells with silver nanowire (AgNW) networks. The AgNW network was used as an electrode of LC cell as a substitute for an indium-tin-oxide (ITO) film. LC alignment characteristics in the LC cell using AgNW networks, which have two different sheet resistances of $60{\Omega}/m^2$ and $80{\Omega}/m^2$, were observed. The LC alignment characteristics including pretilt angle, LC alignment state, and thermal stability are similar irrespective of sheet resistance of AgNW network. However, twisted-nematic (TN)-LC cell normally operated when using AgNW network with sheet resistance of $80{\Omega}/m^2$. Electrooptical properties of TN-LC cell exhibited competitive performance compared to those of TN-LC cell based on conventional ITO electrode, which allow new approaches to replace conventional ITO electrode in display technology.

• Journal of the Korean institute of surface engineering
• /
• v.54 no.2
• /
• pp.71-76
• /
• 2021

Ag925, silver with added copper, is popular alloy due to its low price. However, it has a difficult to use because of the low corrosion resistance. In various alloys, neodymium (Nd) works as an element to improve corrosion resistance by reacting with interstitial elements in the alloy. When 1.5 wt. % Neodymium was added to Ag925, the potential on the activated polarization in a potentiodynamic polarization test was increased from -0.15 V to -0.05 V. Ag925 with added neodymium showed the passivation after activation polarization. But When the potential increased around 50 mV, the current density is increased to 3 × 10-3. Ag925 with the 1.5 wt. % Nd had the low corrosion rate.

• Journal of Life Science
• /
• v.7 no.4
• /
• pp.316-321
• /
• 1997

The effects of the silver ion-exchanged water treatment agent (Ag-Os) upon E. coli RB 797 and Bacillus sp. have been discussed in this study. Silver ion causes a number of toxic effects with no known biological function. Silver ion-exchanged water treatment agent (Ag-Os) using oyster shell here showed antimicrobial activities. the soluble form of silver ion in water is more toxic to the growth of Bacillus sp. than that of E. Coli RB 797. The minium amount of Ag-Os needed for growth inhibition is 0.2 mg/ml for E. Coli RB 797 and 0.02 mg/ml for Bacillus sp., which is consistant with the data of the survival cell fraction. Binding studies suggested that binding of silver to the cell surface was a rapid, metabolic-independent process and different from active transport. Bacillus sp. showed more binding than E. Coli RB 797. Reducing substances of the cell cultures in the presence of Ag-Os was detected using Methylen blue as an indicator. From these results, we suggest that Ag-Os is effective as an antimicrobial agent on E. Coli RB 797 and Bacillus sp. and silver binds to the cells through rapid, metabolic-independent process and might complex to sulfur group in the cells for its toxicity.

• Polymer(Korea)
• /
• v.33 no.1
• /
• pp.33-38
• /
• 2009

Monodisperse polystyrene and its copolymer beads containing amine function were prepared for the electroless silver plating using reduction of silver alkylcarbamate complex in organic solvent. Soap-free emulsion polymerization was adopted for the polymerization of styrene, divinylbenzene (DVB), and 2-(N,N-dimethylamino) ethyl methacrylate (DAEMA) in the presence of poly (vinyl alcohol) in a water/methanol solvent. The resulting poly (styrene/DVB/DAEMA), containing 30/0$\sim$1.5/0$\sim$3 wt% in monomer composition, were found to be a sphere-type particle with diameter of 1 ${\mu}m$. Silver Ag-coated polystyrene beads were prepared by in sito reduction of a silver 2-ethylhexylcarbamate (Ag-EHCB) complex solution with hydrazine without pretreatment of polystyrene beads. Robust Ag/polystyrene beads were analyzed by SEM, UV -visible spectrometer and XRD.