To fabricate intermetallic nanoparticles with high oxygen reduction reaction activity, a high-temperature heat treatment of 700 to 1,000 °C is required. This heat treatment provides energy sufficient to induce an atomic rearrangement inside the alloy nanoparticles, increasing the mobility of particles, making them structurally unstable and causing a sintering phenomenon where they agglomerate together naturally. These problems cannot be avoided using a typical heat treatment process that only controls the gas atmosphere and temperature. In this study, as a strategy to overcome the limitations of the existing heat treatment process for the fabrication of intermetallic nanoparticles, we propose an interesting approach, to design a catalyst material structure for heat treatment rather than the process itself. In particular, we introduce a technology that first creates an intermetallic compound structure through a primary high-temperature heat treatment using random alloy particles coated with a carbon shell, and then establishes catalytic active sites by etching the carbon shell using a secondary heat treatment process. By using a carbon shell as a template, nanoparticles with an intermetallic structure can be kept very small while effectively controlling the catalytically active area, thereby creating an optimal alloy catalyst structure for fuel cells.

수처리 후 직접 해양으로 배출하는 산업시설 등에서 Hazardous and Noxious Substance (HNS) 농도 변화를 연속 자동 측정하기 위 한 센서의 기본적 성능으로 상온에서도 ppb 수준의 검출이 가능한 센서가 필요하다고 판단하여 기존의 센서의 감도를 높이기 위한 방법 을 제안하였다. 우선 나노입자 박막에 전도성 탄소계 첨가물을 이용하여 필름의 전도도를 높이는 방법과 촉매 금속을 이용하여 표면에서 의 이온 흡착도를 높이는 방법에 대해서 각각 연구하였다. 전도성 개선을 위해서 ITO 나노입자를 활용한 필름에 carbon black을 첨가물로 선택하여, 첨가물 함유량에 따른 센서의 성능변화를 관찰하였다. 그 결과 CB 함량 5 wt% 정도에서 전도성 증가에 의한 저항과 응답시간 의 변화를 관찰할 수 있었고, 유기용제를 대상으로 한 실험에서 검출하한은 250 ppb 정도까지 낮아지는 것을 확인하였다. 또한 액체 중 이 온 흡착도를 높이기 위하여 센서 표면에 촉매로 Au를 스퍼터로 제작한 표면 촉매층을 형성한 시료를 이용한 실험에서 센서의 응답은 20% 이상 증가하고 평균 검출하한은 61 ppm까지 낮아지는 것을 확인하였다. 이 결과로부터 금속산화물 나노입자를 활용한 화학저항형 센서가 상온에서도 수십 ppb 정도의 HNS를 검출할 수 있다는 것을 확인하였다.

해수 중 존재하는 유해화학물질 검출을 목적으로 센서 시작품 제작하고 성능을 확인하였다. 센서 시작품은 검지부, 기구부, 구 동부로 구성하였다. 센서의 검지부는 ITO (Indium-Tin-Oxide) 금속산화물 나노입자 (metal oxide nanoparticle) 필름을 기판위에 인쇄하여 제작 하였고, 온도와 HNS 농도를 동시에 검출할 수 있도록 2개의 검출 부분을 갖도록 설계하였다. 센서의 기구부는 검지부와 구동부를 연결하 며, 검출에 영향을 줄 수 있는 화학적 반응을 막기 위해 테프론 재질을 이용하여 제작하였고, 특히 검지부의 착탈이 용이하도록 설계 하 였다. 구동부는 브릿지 회로와 아두이노 보드를 이용하여 전원 공급과 데이터 측정 및 디스플레이가 가능하도록 제작하였다. 시작품의 성 능에 대해서는 기존의 수질 센서를 참고한 성능 사양을 제시하고, 유기용제를 사용한 검지부와 시작품의 동작을 확인하여 응답 (ΔR), 검 출하한 (Limit of Detection), 응답시간 (response time), 오차 (error) 등을 평가하였다. 또한 해수 중 동작 특성을 파악하여 설계 사양이 구현되 었는지 확인하였다.

Irradiation of the metal nanoparticles causes local plasmon resonance in a specific wavelength band, which can improve the absorption and scattering properties of a structure. Since noble metal nanoparticles have better resonance effects than those of other metals, it is easy to identify plasmonic reactions and this is advantageous to find the optical tendency. Compared to having a particle gap or randomly arranged particle structures, densely and evenly packed structures can exhibit more uniform optical properties. Using the uniform properties, the structure can be applied to optical filtering applications. Therefore, in this paper, validation tests about metal nanoparticles and thin film structures are conducted for more accurate analysis. The optical properties of monolayer and bilayer noble metal nanoparticle structures with different diameters, packed in a uniform array, are investigated and their optical trends are analyzed. In addition, a thin film structure under identical conditions as metal nanoparticle structure is evaluated to confirm the improved optical characteristics.

본 연구에서는 수용성 도료의 내후성 및 내광성을 향상 시키고 광택도 및 비극성수지와의 결합을 조절하기 위해 수용성 도료와 표면 개질된 금속 산화물 나노입자를 혼합하여 물성 변화 특성을 연구하였다. SiO2, TiO2를 실란커플링 제로 표면개질 하여 수용성 도료에 혼합하였으며, 볼밀을 이용하여 금속산화물 나노입자를 수용성 도료에 분산 시켰다. (3-Glycidoxypropyl) trimethoxysilane (GPS)로 표면 개질된 금속 산화물 나노입자를 VOC(Volatile Organic Compounds), 저장 안정성 평가 및 광택을 측정하였다.

In this study, we prepare polymer solar cells incorporating organic ligand-modified Ag nanoparticles (O-AgNPs) highly dispersed in the P3HT:PCBM layer. Ag nanoparticles decorated with water-dispersible ligands (W-AgNPs) were also utilized as a control sample. The existence of the ligands on the Ag surface was confirmed by FT-IR spectra. Metal nanoparticles with different surface chemistries exhibited different dispersion tendencies. O-AgNPswere highly dispersed even at high concentrations, whereas W-AgNPs exhibited significant aggregation in the polymerlayer. Both dispersion and blending concentration of the Ag nanoparticles in P3HT:PCBM matrix had critical effects onthe device performance as well as light absorption. The significant changes in short-circuit current density (JSC) of thesolar cells seemed to be related to the change in the polymer morphology according to the concentration of AgNPsintroduced. These findings suggested the importance of uniform dispersion of plasmonic metal nanoparticles and theirblending concentration conditions in order to boost the solar cell performance.

has the characteristic is controlling the inhibition or promotion of particle growth by adsorbing onto specific facets of platinum nanoparticles. Therefore, in this study, was added to control the shape of platinum nanoparticles during the liquid phase reduction process. Consequently, platinum cubes were synthesized when of 1.1 mol% (with respect to the Pt concentration) was added into the solution. Platinum octahedrons were synthesized when 32 mol% (with respect to the Pt concentration) was added into the solution. These results demonstrate that the metal salt , effectively controlled the relative growth rates of each facet of Pt nano particles.

This study shows that catalytic activity of bimetallic RhPt nanoparticle arrays under CO oxidation can be tuned by varying the size and composition of nanoparticles. The tuning of size of RhPt nanoparticles was achieved by changing concentration of rhodium and platinum precursors in one-step polyol synthesis. Two-dimensional RhPt bimetallic nanoparticle arrays in different size and composition were prepared through Langmuir-Blodgett thin film technique. CO oxidation was carried out on these two-dimensional nanoparticle arrays, revealing higher activity on the smaller nanoparticles compared to the bigger nanoparticles. X-ray photoelectron spectroscopy (XPS) results indicate the preferential surface segregation of Rh compared to Pt on the smaller nanoparticles, which is consistent with the thermodynamic analysis. Because the catalytic activity is associated with differences in the rates of dissociative adsorption between Pt and Rh, this paper suppose that the surface segregation of Rh on the smaller bimetallic nanoparticles is responsible for the higher catalytic activity in CO oxidation. This result suggests a control mechanism of catalytic activity via synthetic approaches of colloid nanoparticles, with possible application in rational design of nanocatalysts.

최근프린팅기술은 전자부품소재 산업의 대형화 및 저가격화의 해법으로 기대되고 있다. 특히 전자부품소재 프린팅 기술 중 잉크젯공정은 최신 디스플레이용 전극소재, PCB, FPCB 및 기타 소재공정에 이용하려는 움직임이 활발히 진행되고 있다. 그러나 잉크젯 기술은 재료의존도 비중이 높은 기술로서 소재(금속잉크)의 개발이 최우선시 되어야한다. 전자부품소재용 금속잉크에 사용되는 금속 나노입자는 우수한 전기전도성과 산업적응용이 가능해야 한다. 따라서 최근 연구되고

Airborne bacteria, fungi, and viruses are known to have adverse effects on human health. Various antimicrobial agents have been used to prohibit the growth of microorganisms on the surfaces of air filter media. In this study, nano-sized silver and copper particles were tested for their antifungal effects on indoor fungi, Cladosporium cladosporioides and Aspergillus versicolor. The growth circle of the fungi was observed on a solid agar plate containing the two nanoparticles. The nanoparticle concentration ranged from 0 to 500 μg/mL. The size of fungal growth circle seemed to decrease with increasing nanoparticle concentration in agar plates, indicating that silver and copper nanoparticles have antifungal properties against C. cladosporioides and A. versicolor.

Storm water pollution has been the various concerns over the past decade. Decreasing the contamination levels of runoffs to the minimum accepted levels to protect the water quality of rivers, estuaries, streams, lakes, seas, and other bodies of waters have been the objectives of various storm water best management practices (BMP) implemented. BMPs has been augmented to existing water treatment facilities to provide additional resources for potable water usage. Novel filter materials are used to improve the performance of media filters and extend their capabilities to removing other pollutants such as organic/aromatic hydrocarbons and heavy metals. Among the novel materials being considered are photocatalyst nanoparticles coated into the sand media filter. Photocatalysts have been applied in the degradation of organic pollutants with the help of visible light irradiation. This paper describes the synthesis and use of nanoparticle–coated zeolite media filter to remove dissolved metals (Cu and Zn). Catalyst surface analysis revealed that the Cu and Zn were chemically adsorbed, and were transformed into its corresponding elemental forms.

금속나노입자는 진단이나 치료를 포함한 의생명응용분야에 있어 매력적인 특징들을 갖고 있다. 양성자 빔 치료를 위한 방사선증감제로 사용하기 위해 가교덱스트란이 코팅된 산화철나노입자(SPIONs)와 실리카가 코팅된 산화가돌리늄나노입자(SPGONs)를 합성하였다. 덱스트란과 실리카는 각각 SPIONs와 SPGONs의 보호수단이다. 합성된 SPIONs와 SPGONs를 투과전자현미경(TEM)으로 분석한 결과 각각 평균 직경이 3~5 nm와 30~100 nm였다. 합성된 방사선 증감제의 효과를 평가하기 위해 세포생존곡선 측정과 Western blotting을 수행하였다. 측정된 세포생존곡선으로부터 계산된 90% 세포사멸 시 방사선증감비는 SPIONs와 SPGONs에 대하여 각각 1.23과 1.03이었다. Western blotting 결과 역시 Cytochrome C의 발현량이 SPIONs를 처리한 암세포에서 유의적으로 증가됨을 보였다.