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.

Silver nano-particles, that were either attached on granular activated carbon or dispersed in a liquid solution, were applied to investigate the removal efficiency of airborne bacteria. The antibacterial experiments were performed by changing the gas residence time in a GAC filtration column and a scrubber module. The GAC filter experiment showed that the antibacterial efficiency declined with time at a gas residence time (RT) of 0.02 second, and the bacterial quantity in the outlet of the column exceeded that of the inlet after 30 hours of operation. However, when using Ag-GAC, the removal efficiency was higher than that of the GAC, and it was maintained over a 3-day period. The experiment results at different gas RTs of 3, 1.5 and 0.5 seconds also showed that Ag-GAC had higher antibacterial efficiencies. The low antibacterial efficiency at a short RT indicates that a careful consideration needs to be implemented for the design of indoor air purification devises. In the scrubber experiment using distilled water, a removal efficiency of 50% was observed initially; however, it declined gradually and the outlet bacterial quantity was even higher than that of the inlet. This result was mainly due to the accumulation of bacteria in the recirculating solution. Contrarily, another scrubber experiment using silver nano-particle solution showed that an antibacterial efficiency of 66% was maintained over a 3-day period. Silver nano-particles were able to minimize the growth of microorganisms in the spray solution, and it resulted in an improved and stable efficiency for the airborne bacterial control.

목적: 본 연구는 안경수건에 함유된 은나노 입자의 항균효과를 연구하기 위해 수행되었다. 방법: 은나노 입자가 함유된 안경수건과 함유되지 않은 안경수건의 세균수를 비교하였다. 결과: 은나노입자가 함유된 안경수건에서 뚜렷한 세균수의 감소가 관찰되었으며, 이 결과는 안경렌즈에 존재하는 세균에 대해 은나노 입자가 높은 항균성을 가짐을 의미한다. 결론: 가까운 미래에 나노기술을 이용한 항균작용 안경수건의 개발이 기대된다.

This paper presents a novel single-step method to prepare the Ag nanometallic particle dispersed fluid (nanofluid) by electrical explosion of wire in liquid, deionized water (DI water). X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM) were used to investigate the characteristics of the Ag nanofluids. Zeta potential was also used to measure the dispersion properties of the as-prepared Ag nanofluid. Pure Ag phase was detected in the nanofluids using water. FE-SEM analysis shows that the size of the particles formed in DI water was about 88 nm and Zeta potential value was about -43.68 without any physical and chemical treatments. Thermal conductivity of the as-prepared Ag particle dispersed nanofluid shows much higher value than that of pure DI water.

Silver particles were synthesized from silver nitrate by homogeneous precipitation and chemical reduction methods involving the intermediate silver cyanate. The obtained silver particles were characterized by XRD, SEM, TEM, and BET. Urea which could prevent the agglomeration of the reduced silver particles was used as a homogeneous precipitator. The spherical silver particles with average particle diameter of 100 nm were obtained under the optimum reaction conditions. The optimum synthetic conditions were found as follows: reaction temperature , reaction time 60 min, concentration of silver nitrate mol, urea mol, and sodium citrate mol. The phase of obtained silver particles was crystalline state and the silver particles were relatively dense, which had the surface area of .

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.

Carbon nanotube (CNT) cathodes were fabricated using nano-sized silver (Ag) powders as a bonding material between the CNTs and cathode electrodes. The effects of the powder size on the sintering behavior, the current density and emission image for CNT cathodes were investigated. As the diameter of the Ag powders decreases to 10 nm, the sintering temperature of the CNT cathode was lowered primarily due to the higher specific surface area of the Ag powders. In this study, it was demonstrated that nano-sized Ag powders can be feasibly used as a bonding material for a screen-printed CNT cathode, yielding a high current density and a uniform emission image.

Silver nanoparticles was synthesized by the method of W/O microemulsions with AOT (bis(2-ethylhexyl) sodium sulfosuccinate). The nucleation particle growth and aggregation was controlled by the droplet exchange process. The intermicellar exchange reaction is varied by changing the AOT and the H2O concentration. The synthesized W/O microemulsions was found to give the nanoparticles, which was confirmed by SEM, TEM, particle-size-analyzer, and UV-spectrometer. The most stable particles was obtained at 0.056 mole AOT solution, and the particle size distribution was found in the range from 27 to 31 nm. The mean particle size was reduced by adding Tween 20 significantly, and distribution was found from 14 to 16 nm. And, It's size was reduced by cosurfactants as toluene and benzyl alcohol. In case of toluene and benzyl alcohol, the range of particle size was found 7~11 nm and 8~12 nm.

Background : Anemarrhena asphodeloides has efficacy such as anti-fungal, anti-cancerous, anti-inflammatory, anti-diabetic, Anti-UV etc. Metal nanoparticles are used for photo imaging, cancer resection and drug delivery etc in medical field. Therefore A. asphodeloides nanoparticles will be expected better efficacy for therapeutic properties in medical field. Methods and Results : The water extract of A. asphodeloides mediated the synthesis of Aa-AgNPs and Aa-AuNPs. Their characterized by several physicochemical techniques such as UV-Vis spectrophotometry, FE-TEM, EDX spectroscopy, SAED pattern, DLS size analysis, XRD analysis, and FTIR analysis. Both Aa-Ag/AuNPs were evaluated for cytotoxicity towards 3T3-L1, A549, HT29 and MCF7. Aa-AgNPs and Aa-Au NPs were found to be spherical, face-centered cubic nanocrystals with hydrodynamic diameter of 190 and 258 ㎚. In vitro cytotoxic analysis revealed that up to 50 ㎍/㎖-1 concentration Aa-Au NPs did not exhibit any toxicity on 3T3-L1, HT29 and MCF7 cell lines, while being specifically cytotoxic to A549 cell line. On the contrary, Aa-Ag NPs displayed a significantly higher toxicity in all cell lines specially MCF7 cell line. ROS generation was not affected by Aa-Au NPs, but Aa-AgNPs has a higher potential to induce oxidative stress in A549 cells than HT29 and MCF7 cells. Aa-Au NPs have the potential for anticancer agent during lung cancer treatment. Aa-AgNPs is also exhibited to inhibit cell migration by induce oxidatie stress. Conclusion : The Aa-Au/AgNPs might have the anticancer potential and might be effective in the lung cancer therapy, however further evaluation is must needed.