목적 : 본 연구는 항균 기능을 갖춘 안경테의 필요성에 주목하여 고분자 물질인 Polyvinylpyrrolidone(PVP)을 사용하여 은 나노 입자를 합성하고, 금속 안경테 소재에 코팅하여 항균성과 코팅 특성을 평가해 보고자 한다. 방법 : 안정성이 높은 고분자 물질인 PVP를 환원제, 분산제, 안정제로 사용하고 합성 온도를 달리하여 은 나노 입자를 합성하였다. 합성한 시료의 특성은 UV-visible spectrophotometer, SEM, EDS를 사용하여 분석하였으 며 paper disk diffusion method로 항균성을 평가하였다. 합성한 은 나노콜로이드를 금속 안경테 소재인 티타 늄, 스테인리스스틸 기판에 코팅하고 코팅막의 특성과 항균성을 측정하였다. 결과 : PVP를 사용하여 합성한 시료 모두에서 은(Ag)이 검출되어 은 나노 입자의 생성을 확인할 수 있었다. 합성 온도에 따른 은 나노 입자의 크기는 차이를 보였으며 Escherichia coli, Pseudomonas aeruginosa, Aspergillus brasiliensis의 경우 45℃에서 합성한 은 나노콜로이드의 항균활성이 가장 크게 나타났다. 이를 금속 안경테 소재 기판에 코팅한 후 항균성을 확인한 결과 코팅막의 항균력을 확인할 수 있었다. 결론 : PVP를 사용하여 합성한 은 나노콜로이드를 금속 안경테 소재 기판에 코팅한 결과 코팅막의 항균성이 확인되어 항균 기능을 가진 안경테 제작 시 항균 물질로 활용될 수 있을 것이라 사료된다.

물 여과, 단백질 정제 또는 생체 의학 여과 장치에 사용되는 분리막은 여러 가지 이유로 막 파울링을 거치게 된다. 박테리아에 의한 막 표면의 바이오필름 형성은 분리막의 내구성에 심각한 문제를 초래한다. 단백질 정제의 경우, 소수성 인 막의 표면으로 인해 막의 기공이 막히게 된다. 분리막의 파울링을 조절하는 방법에는 여러 가지가 있는데, 그 중 하나가 은나노 입자의 도입이다. 은나노 입자의 항균 특성은 잘 알려져 있고 따라서 여러 응용에 사용되고 있다. 본 총설에서는 은나 노 입자 또는 그 유도체가 박막 활성층에 도입되거나 또는 복합막 전체에 균일하게 분포된 분리막에 초점을 두었다.

This study investigates Ag coated Cu2O nanoparticles that are produced with a changing molar ratio of Ag and Cu2O. The results of XRD analysis reveal that each nanoparticle has a diffraction pattern peculiar to Ag and Cu2O determination, and SEM image analysis confirms that Ag is partially coated on the surface of Cu2O nanoparticles. The conductive paste with Ag coated Cu2O nanoparticles approaches the specific resistance of 6.4 Ω·cm for silver paste(SP) as (Ag) /(Cu2O) the molar ratio increases. The paste(containing 70 % content and average a 100 nm particle size for the silver nanoparticles) for commercial use for mounting with a fine line width of 100 μm or less has a surface resistance of 5 to 20 μΩ·cm, while in this research an Ag coated Cu2O paste has a larger surface resistance, which is disadvantageous. Its performance deteriorates as a material required for application of a fine line width electrode for a touch panel. A touch panel module that utilizes a nano imprinting technique of 10 μm or less is expected to be used as an electrode material for electric and electronic parts where large precision(mounting with fine line width) is not required.

We applied column experiments to investigate the environmental fate and transport of silver nanoparticles(AgNPs) in fully saturated conditions of porous media. These column experiments were performed to emphasize oxidation method with H2O2 concentration and acidic conditions. The mobility of AgNPs was decreased with the increasing ionic strength that the surface charge of AgNPs(zeta potential) was neutralized with the presence of positive ions of Na+. Additionally, it was also affected due to that not only more increased aggregated size of AgNPs and surface charge of quartz sand. The decreased breakthrough curves(BTCs) of bisphenol-A(BPA) and 17α-ethynylestradiol(EE2) were removed approximately 35.3 and 40%. This is due to that endocrine disrupting chemicals(EDCs) were removed with the release of OH․ radicals by the fenton-like mechanisms from acidic and fenton-like reagent presenting. This results considered that higher input AgNPs with acidic conditions is proved to realistic in-situ oxidation method. Overall, it should be emphasized that a set of column experiments employed with adjusting pH and H2O2 concentration in proved to be effective method having potential ability of in-situ degradation for removing organic contaminants such as BPA and EE2.

이전 연구에서 올레핀/파라핀 분리를 위해 poly(ethylene oxide)(PEO)/Ag nanoparicles (AgNPs)(전구체AgBF4)/pbenzoquinone (p-BQ) 복합막이 제조되었으며, 이 복합체 분리막의 성능은 100시간까지 선택도 10과 투과도 15 GPU로 유지 되는 것이 확인되었다. 하지만 전구체인 AgBF4의 가격이 고가이기 때문에, 본 연구에서는 가격 측면에서 경쟁력이 있는 AgNO3를 Ag nanoparticles의 전구체로 사용하여 실험을 진행하였다. 그 결과 이미 존재하고 있는 NO3 -가 AgNPs를 감싸고 있기 때문에 분리 성능이 나오지 않는 것으로 관찰되었다. 이번 연구에서는 AgNO3를 Ag nanoparticles의 전구체로 사용하여도 높은 성능을 내기 위해 전자수용체 7,7,8,8-tetracyanoquinodimethane (TCNQ)를 사용하여 PEO, polyvinyl alcohol (PVA), polyether block amide-1657 (PEBAX-1657) 고분자 복합막을 제조한 결과, 고분자와 전자수용체의 영향과는 무관하게 분리 성능을 내지 못하는 것으로 분석되었으며, 이는 분리성능에 전구체의 음이온이 결정적 역할을 하는 것으로 분석되었다.

An imprinted potentiometric sensor was developed for direct and selective determination of gabapentin. Sensor is based on carbon paste electrode adapted by graphene oxide that is decorated with silver nanoparticles and mixed with molecularly imprinted polymers nanoparticles using gabapentin as a template molecule. The synthesized nanoparticles were characterized by Fourier transmission infrared spectroscopy, transmission electron microscopy and X-ray diffraction. Under optimal experimental conditions, the studied sensor exhibited high selectivity and sensitivity with LOD of 4.8×10–11 mol L–1. It provided a wide linearity range from 1×10–10 to 1×10–3 mol L–1and high stability for more than 3 mo. The sensor was effectively used for the determination of gabapentin in pharmaceutical tablets and spiked plasma samples.

In this paper, the recovery and nanoparticle synthesis of Ag from low temperature co-fired ceramic (LTCC) by-products are studied. The effect of reaction behavior on Ag leaching conditions from the LTCC by-products is confirmed. The optimum leaching conditions are determined to be: 5 M HNO3, a reaction temperature of 75℃, and a pulp density of 50 g/L at 60 min. For the selective recovery of Ag, the [Cl]/[Ag] equivalence ratio experiment is performed using added HCl; most of the Ag (more than 99%) is recovered. The XRD and MP-AES results confirm that the powder is AgCl and that impurities are at less than 1%. Ag nanoparticles are synthesized using a chemical reduction process for recycling, NaBH4 and PVP are used as reducing agents and dispersion stabilizers. UV-vis and FE-SEM results show that AgCl powder is precipitated and that Ag nanoparticles are synthesized. Ag nanoparticles of 100% Ag are obtained under the chemical reaction conditions.

There has been much interest in recycling electronic wastes in order to mitigate environmental problems and to recover the large amount of constituent metals. Silver recovery from electronic waste is extensively studied because of environmental and economic benefits and the use of silver in fabricating nanodevices. Hydrometallurgical processing is often used for silver recovery because it has the advantages of low cost and ease of control. Research on synthesis recovered silver into nanoparticles is needed for application to transistors and solar cells. In this study, silver is selectively recovered from the by-product of electrodes. Silver precursors are prepared using the dissolution characteristics of the leaching solution. In the liquid reduction process, silver nanoparticles are synthesized under various surfactant conditions and then analyzed. The purity of the recovered silver is 99.24%, and the average particle size of the silver nanoparticles is 68 nm.

Noncontact direct-printed conductive silver patterns with an enhanced electrical resistivity are fabricated using a silver ink with a mixture of silver nanoparticles and nanoplates. The microstructure and electrical resistivity of the silver pattern are systematically investigated as a function of the mixing ratio of the nanoparticles and nanoplates. The pattern, which is fabricated using a mixture with a mixing ratio of 3(nanoparticles):7(nanoplates) and sintered at 200oC shows a highly dense and well-sintered microstructure and has a resistivity of 7.60 μΩ·cm. This originates a mutual synergistic effect through a combination of the sinterability of the nanoparticles and the packing ability of the nanoplates. This is a conductive material that can be used to fabricate noncontact direct-printed conductive patterns with excellent electrical conductivity for various flexible electronics applications, including solar cells, displays, RFIDs, and sensors.

Pollutants removal and disinfection effect of secondary effluent from final settling tank of sewage treatment plant of W city were investigated in Loop Reactor using ordinary granular activated carbon(GAC) and GAC coated with silver nanoparticles. The results showed that the removal efficiency of CODMn, T-N and T-P using GAC with silver nanoparticles were higher than using the ordinary GAC. The removal efficiency of T-P using GAC with silver nanoparticles is 45.4% and that of T-P using ordinary GAC is 30.9% in the same case of the input amount of 20 g/L of GAC. The total califorms is reduced according to increasing input amount of GAC with silver nanoparticles and ordinary GAC. The disinfection efficiency of total coliforms in case of GAC with silver nanoparticles is much higher than that in case of ordinary GAC. For all experiments using the silver nanoparticles, the total coliforms is under 26 cfu/mL and this shows very excellent disinfection effect.

Facilitated olefin transport membrane, containing positively charged silver nanoparticles (AgNPs) as olefin carriers dispersed in poly(vinyl pyrrolidone) (PVP), leads extremely high separation performances for propylene/propane mixtures. In this study, as representatives of electron withdrawing nitrobenzene compounds, 1,2-dinitrobenzene (DNB) and 3,4-dinitro toluene (DNT) were used for PVP/AgNPs membranes. The correlation between the surface charge density of AgNPs and the separation performance was investigated with X-ray photoelectron spectroscopy (XPS). A fairly good linear correlation between the surface charge density and the separation performance was confirmed, which meant that the positive charge density on the surface of AgNPs may be a key factor in determining the separation performance of facilitated olefin transport membranes.

In this study, the properties of Ag-coated TiO2 nanoparticles were observed, while varying the molar ratio of water and Ag+ for the surfactant and TiO2. According to the XRD results, each nanoparticle showed a distinctive diffraction pattern. The intensity of the respective peaks and the sizes of the nanoparticles increased in the order of AT1(R1 = 5)(33.3 nm), AT2 (R1 = 10)(38.1 nm), AT3(R1 = 20)(45.7 nm), AT4(R1 = 40)(48.6 nm) as well as AT5(R2 = 0.2, R3 = 0.5)(41.4 nm), AT6(R2 = 0.3, R3 = 1)(45.1 nm), AT7(R2 = 0.5, R3 = 1.5)(49.3 nm), AT8(R2 = 0.7, R3 = 2)(57.2 nm), which values were consistent with the results of the UV-Vis. spectrum. The surface resistance of the conductive pastes fabricated using the prepared Ag-coated TiO2 nanoparticles exhibited a range 7.0~9.0(274~328 μΩ/cm2) times that of pure silver paste(ATP)(52 μΩ/cm2).

Soil column experiments were evaluated effects of silver nanoparticles (i.e., 0, 2.5, 5, and 10 mg/L) on the microbial viability which is strongly associated with the degradation of organic matter, pharmaceutically active compounds(PhACs) and biological oxidation of nitrogenous compounds during river bank filtration. The addition of silver nanoparticles resulted in almost no change in the aqueous matrix. However, the intact cell concentration decreased with addition of silver nanoparticles from 2.5 to 10 mg/L, which accounted for 76% to 82% reduction compared to that of control (silver nanoparticles free surface water). The decrease in adenosine triphosphate was more pronounced; thus, the number and active cells in aqueous phase were concurrently decreased with added silver nanoparticles. Based on the florescence excitation-emission matrix and liquid chromatograph - organic carbon detection analyses, it shows that the removal of protein-like substances was relatively higher than that of humic-like substances, and polysaccharide was substantially reduced. But the extent of those substances removed during soil passage was decreased with the increasing concentration of silver nanoparticles. The attenuation of ionic PhACs ranged from 55% to 80%, depending on the concentration of silver nanoparticles. The attenuation of neutral PhACs ranged between 72% and 77%, which was relatively lower than that observed for the ionic PhACs. The microbial viability was affected by silver nanoparticles, which also resulted in inhibition of nitrifiers.

목적: 본 연구는 furfuryl isocyanate를 은 나노 물질(Ag nanoparticler)과 기존의 하이드로젤 곤택트렌즈 재료와 공증합 하였으며, 제조된 콘택트렌즈의 물리적 특성을 비교하고, 내구성이 높은 콘택트렌즈 고분자로서의 활용성을 알아보았다. 방법: 교차결합제인 EGDMA(ethylene glycol dimethacrylate)와 HEMA(2-hydroxyethyl methacry-Late), MMA(methyl methacrylate), MA(merhacrylic acid) 그리고 개시제인 AIBN(azobisisobutyronitrile)과 함께 공증합 하였다. 결과: 생성된 고분자의 물리적 특성을 측정한 결과, 함수율 28.98~34.31%, 굴절률 1.441~1.453,UV-B투고율 33.2~72.0%, 접촉각 57.65~79.00° 그리고 인장강도의 경우 0.340~0.71kgf 범위의 분포를 나타내었다. 또한 은 나노 물질 1%에 furfuryl isocyanate를 첨가할수록 UV-B 투과율 저하와 인장강도가 증가한 결과를 보였다. 결론: 본 실험결과로 볼 때 생성된 공중합체는 내구성이 좋고 자외선 차단 효과가 있는 렌즈 재료로 유용하게 활용될 것으로 기대된다.

In this work, the silver nanoparticles have been synthesized by electrical explosion of wire in three liquid mediums: deionized water (DIW), polyvinylpyrrolidone (PVP) and sodium dodecyl benzene sulfonate (SDBS) solutions. Absorption in the UV-visible region of these suspensions was measured in the range of 300-800 nm. A surface plasmon peak was observed at ~400 nm in all suspensions in measured wavelength range. Particle size was analyzed by transmission electron microscope. It showed that the particles had nearly spherical shape in all samples. The average particle sizes prepared in DIW, PVP and SDBS solution were 37, 31 and 27 nm, respectively. Stability of the suspensions was estimated by multiple light scattering method. The presence of PVP and SDBS surfactants in the exploding medium resulted in enhanced stability of the silver suspensions.

Poly(vinyl chloride)-g-poly(styrene sulfonic acid) (PVC-g-PSSA) 가지형 공중합체를 합성한 후, 이를 이용하여 80℃에서 열적으로 환원하여 은 나노입자를 제조하였다. 반응 시간을 바꿈에 따라 다양한 구조의 은 나노입자를 제조하는데 성공하였다. 1시간 정도의 짧은 반응 시간에서는 가지형 공중합체의 미세 상분리 구조를 크게 변화시키지 않고 5 nm 크기의 작은 은 나노입자가 생성되었다. 5시간 정도의 중간 반응 시간에서는 30 내지 50 nm 정도의 크기를 갖는 은 나노입자가 생성되었다. 18시간 정도의 긴 반응 시간에서는, 은입자가 뭉친 허리케인 모양의 은 집합체가 관찰되었다.

원자전달 라디칼 중합을 이용하여 polystyrene-b-poly(oxyethylene methacrylate) (PS-b-POEM) 블록 공중합체를 합성하고, FT-IR을 통해 중합이 성공적으로 이루어졌음을 확인하였다. 또한 자기 조립된 블록 공중합체 막을 제조한 후, 전구체 AgCF3SO3 도입과 UV 조사를 통해 고체상에서 은 나노입자를 성장시켰다. TEM 전자현미경과 UV-visible 분광학 분석을 통해 블록 공중합체 막의 내부에 은 나노입자가 형성된 것을 확인하였고, 또한 친수성 POEM 영역의 함량을 조절함으로써 나노입자의 크기를 조절할 수 있었다. 금속 나노입자를 제조하는 데 있어서 POEM 함량이 적은 블록 공중합체가 더 효과적임을 확인하였다.

The effect of silver nanoparticles (NPs) incorporation on the electronic properties of poly (3, 4-ethylenedioxythiphene) : poly(styrenesulfonate) (PEDOT : PSS) films was investigated. The surface of silver NPs was stabilized with trisodium citrate to control the size of silver NPs and prevent their aggregation. We obtained ca. 5 nm sized silver NPs and dispersed NPs in PEDOT : PSS solution. Sheet resistance, surface morphology, bonding state, and work function values of the PEDOT : PSS films were modified by silver NPs incorporation as well as annealing temperature. Sodium in silver NPs solution could lead to a decrease of work function of PEDOT : PSS; however, large content of silver NPs have an effect on the increase in work function, resulting from charge localization on the silver NPs and a decrease in the number of charge-trapping-related defects by chemical bond formation.