• Journal of Magnetics
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• 제16권2호
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• pp.164-168
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• 2011

Magnetic nanoparticles can potentially be used in drug delivery systems and for hyperthermia therapy. The applicability of $Fe_3O_4$, $CoFe_2O_4$, $MgFe_2O_4$, and $NiFe_2O_4$ nanoparticles for the same was studied by evaluating their magnetization, thermal efficiency, and biocompatibility. $Fe_3O_4$ and $CoFe_2O_4$ nanoparticles exhibited large magnetization. $Fe_3O_4$ and $NiFe_2O_4$ nanoparticles exhibited large induction heating. $MgFe_2O_4$ nanoparticles exhibited low magnetization compared to the other nanoparticles. $NiFe_2O_4$ nanoparticles were found to be cytotoxic, whereas the other nanoparticles were not cytotoxic. This study indicates that $Fe_3O_4$ nanoparticles could be the most suitable ones for hyperthermia therapy.

• 청정기술
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• 제23권1호
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• pp.27-33
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• 2017

본 연구에서는 중금속 7종(Cu, Cd, Cr, As(III), As(V), Zn, Ni) 및 나노입자 5종(CuO, ZnO, NiO, $TiO_2$, $Fe_2O_3$)에 대한 독성을 수계 대표 생물종인 녹조류 Chlorella vulgaris를 이용한 생물검정법으로 평가하였다. 조류에 미치는 영향은 흡광도, 클로로필 및 개체수 측정에 대한 결과를 통합하여 평가하였다. 중금속의 통합결과독성($TEC_{50}$) 순서는 Cr ($0.7mgL^{-1}$) > Cu ($1.7mgL^{-1}$) > Cd ($3.2mgL^{-1}$) > Zn ($3.9mgL^{-1}$) > Ni ($13.2mgL^{-1}$) > As(III) ($17.8mgL^{-1}$) ${\gg}$ As(V) (> $1000mgL^{-1}$)로 나타났다. 중금속은 측정종말점에 따라 일부 상이한 민감도와 독성이 조사되었다. 나노입자의 독성($TEC_{50}$) 순서는 ZnO ($2.4mgL^{-1}$) > NiO ($21.1mgL^{-1}$) > CuO ($36.6mgL^{-1}$) > $TiO_2$ ($62.5mgL^{-1}$) > $Fe_2O_3$ ($82.7mgL^{-1}$)로 나타났다. 나노입자는 측정종말점간에 비슷한 민감도와 독성을 보였다. 따라서 오염물의 독성을 평가하기 위해서 단일 방법에 의한 결과보다는 다양한 측정종말점의 통합결과에 근거한 접근이 적절할 것이다.

• 대한환경공학회지
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• 제36권6호
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• pp.396-401
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• 2014

나노물질은 다양한 분야에 널리 사용되고 있다. 본 연구에서는 Lactuca(상추)와 Raphanus(알타리무) 씨앗의 발아와 발아지수에 금속산화물 나노입자(CuO, NiO, $Fe_2O_3$, $Co_3O_4$, $TiO_2$, ZnO)가 미치는 영향을 조사하였다. 용액상 노출에서 CuO가 가장 큰 영향을 나타내었으며, 발아와 발아지수의 $EC_{50}$는 각 0.46 mg/L와 0.37%로 조사되었다. 씨앗 이용 식물독성 측정에서 상추가 알타리무보다 나노입자 노출에 대해 더욱 민감한 반응을 나타내었다. 일반적으로 나노입자의 씨앗발아와 발아지수에 근거한 영향은 다음의 순서로 조사되었다: CuO > ZnO >NiO > $TiO_2$, $Fe_2O_3$, $Co_3O_4$. 특히 $TiO_2$, $Fe_2O_3$와 $Co_3O_4$는 최대 노출 농도 1,000 mg/L 농도에서도 뚜렷한 영향을 나타내지 않았다.

• 한국수소및신에너지학회논문집
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• 제28권3호
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• pp.238-245
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• 2017

Mg-Ni nanoparticles were synthesized by a physical vapor condensation method (DC arc-discharge) in a mixture of argon and hydrogen atmosphere, using compressed mixture of micro powders as the raw materials. The crystal phases, morphology, and microstructures of nanoparticles were analyzed by means of X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). It was found that the intermetallic compounds of $Mg_2Ni$ and $Mg_2Ni$ formed with existence of phases of Mg, Ni, and MgO in Mg-Ni nanoparticles. After one cycle of hydrogen absorption/desorption process (activation treatment), Mg-Ni nanoparticles exhibited excellent hydrogen absorption properties. $Mg_2Ni$ phase became the main phase by aphase transformation during the hydrogen treatments. The phenomenon of refinement of grain size in the nanoparticle was also observed after the hydrogen absorption/desorption processes, which was attributed to the effect of volume expansion/shrinkage and subsequent break of nanoparticles. Maximum hydrogen absorption contents are 1.75, 2.21 and 2.77 wt.% at 523, 573 and 623 K, respectively.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 추계학술발표대회
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• pp.27.1-27.1
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• 2011

The recent extensive research of one-dimensional (1D) nanostructures such as nanowires (NWs) and nanotubes (NTs) has been the driving force to fabricate new kinds of nanoscale devices in electronics, optics and bioengineering. We attempt to produce silicon oxide nanowires (SiOxNWs) in a simple way without complicate deposition process, gaseous Si containing precursors, or starting material of $SiO_2$. Nickel (Ni) nanoparticles (NPs) were applied on Si wafer and thermally treated in a furnace. The temperature in the furnace was kept in the ranges between 900 and $1,100^{\circ}C$ and a mixture of nitrogen ($N_2$) and hydrogen ($H_2$) flowed through the furnace. The SiOxNWs had widths ranging from 100 to 200 nm with length extending up to ~10 ${\mu}m$ and their structure was amorphous. Ni NPs were acted as catalysts. Since there were no other Si materials introduced into the furnace, the Si wafer was the only Si sources for the growth of SiOxNWs. When the Si wafer with deposition of Ni NPs was heated, the liquid Ni-Si alloy droplets were formed. The droplets as the nucleation sites induce an initiation of the growth of SiOxNWs and absorb oxygen easily. As the droplets became supersaturated, the SiOxNWs were grown, by the reaction between Si and O and continuously dissolving Si and O onto NPs. Photoluminescence (PL) showed that blue emission spectrum was centered at the wavelength of 450 nm (2.76 eV). The details of growth mechanism of SiOxNWs and the effect of Ni NPs on the formation of SiOxNWs will be presented.

• 한국산업보건학회지
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• 제26권2호
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• pp.225-236
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• 2016

Objectives: Nanomaterials have been used in various fields. As use of nanoproducts is increasing, workers dealing with nanomaterials are also gradually increasing. Exposure assessments for nanomaterials have been carried out for protection of worker's health in workplace. Exposure studies were mainly focused on manufacturing processes, but these studies on after-treatment processes such as refinement, weighing, and packing were insufficient. So, we investigated exposure characteristics of particles during after-treatment processes of $Al_2O_3$ fibers and Ni powders. Methods: Mass-production of Ni powder process was carried out in enclosed capture-type canopy hood. In a developing stage, $Al_2O_3$ was handled with a local ventilation unit. Exposure characteristics of particles were investigated for $Al_2O_3$ fiber and Ni powder processes during the periods of 10:00 to 16:00, 20 May 2014 and 13:00 to 16:00, 21 May 2014, respectively. Three real-time aerosol instruments were utilized in exposure assessment. A scanning mobility particle sizer(SMPS, nanoscan, model 3910, TSI) and an optical particle counter(OPC, portable aerosol spectrometer, model 1.109, Grimm) were used to determine the particle size distribution in the size range of 10-420 nm and $0.25-32{\mu}m$, respectively. In addition, a nanoparticle aerosol monitor(NAM, model 9000, TSI) was used to measure lung-deposited nanoparticle surface area. Membrane filters(isopore membrane filter, pore size of 100 nm) were also used for air sampling for the FE-SEM(model S-5000H, Hitachi) analysis using a personal sampling pump(model GilAir Plus by 2.5 L/min, Gilian). Conclusions: For Ni powder after-treatment process, only 27% increase in particle concentration was found during the process. However, for $Al_2O_3$ fiber after-treatment process, significant exposure(1.56-3.34 times) was observed during the process.

• Bulletin of the Korean Chemical Society
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• 제29권9호
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• pp.1737-1741
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• 2008

The electrochemical and thermal stability of $LiNi_{0.8}Co_{0.16}Al_{0.04}O_2$ were studied before and after $Co_3(PO_4)_2$ coating. Different to conventional coating material such as $ZrO_2$ or AlPO4, the coating layer was not detected clearly by TEM analysis, indicating that the $Co_3(PO_4)_2$ nanoparticles effectively reacted with surface impurities such as $Li_2CO_3$. The coated sample showed similar capacity at a low C rate condition. However, the rate capability was significantly improved by the coating effect. It is associated with a decrease of impedance after coating because impedance can act as a major barrier for overall cell performances in high C rate cycling. In the DSC profile of the charged sample, exothermic peaks were shifted to high temperatures and heat generation was reduced after coating, indicating the thermal reaction between electrode and electrolyte was sucessfully suppressed by $Co_3(PO_4)_2$ nanoparticle coating.

• 방사성폐기물학회지
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• 제15권1호
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• pp.15-26
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• 2017

오염수로부터 자성분리가 가능하며, 방사성 세슘을 효율적으로 제거하기 위한 코발트 페로시아나이드(cobalt ferrocyanide, CoFC) 혹은 니켈 페로시아나이드(nickel ferrocyanide, NiFC)가 도입된 자성입자 흡착제를 제조하였다. $Fe_3O_4$ 나노입자는 공침법을 이용해 제조하였고, $Co^{2+}$와 $Ni^{2+}$ 이온을 입자 표면에 도입시키기 위해 금속이온과 금속 배위결합(metalcoordination)을 하는 카르복실기를 포함한 숙신산(succinic acid, SA)을 자성나노입자(magnetic nanoparticles, MNPs) 표면에 코팅하였다. CoFC와 NiFC는 자성나노입자 표면에 도입된 $Co^{2+}$ 혹은 $Ni^{2+}$ 이온이 hexacynoferrate와 결합하여 형성된다. 제조된 CoFC-MNPs 그리고 NiFC-MNPs는 각각 $43.2emu{\cdot}g^{-1}$, $47.7emu{\cdot}g^{-1}$의 우수한 포화자화 값을 보여주었다. X-선 회절분석(XRD), 퓨리에 변환 적외선 분광분석(FT-IR), 나노입자 입도 분석기(DLS), 투과전자현미경(TEM) 등의 분석을 통해 흡착제의 물성을 파악하고, 세슘에 대한 흡착 성능을 알아보았다. 흡착실험을 평가하기 위해 Langmuir/Freundlich 등온흡착식을 이용해 실험 결과 값을 곡선맞춤 하였고, CoFC-MNPs와 NiFC-MNPs의 최대흡착량($q_m$)은 각각 $15.63mg{\cdot}g^{-1}$, $12.11mg{\cdot}g^{-1}$이다. CoFC-MNPs와 NiFC-MNPs는 방사성 세슘에 대해서도 최저 99.09%의 제거율을 가지며, 경쟁이온의 존재에도 방사성 세슘만을 선택적으로 흡착한다.

• 한국세라믹학회지
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• 제53권1호
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• pp.122-127
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• 2016

Tin oxide ($SnO_2$) nanoparticles have been synthesized by solution combustion method using citric acid as a fuel. The oxide to fuel ratio has been varied to obtain ultrafine nanoparticles with better surface area; such particles will be useful in many applications. With this synthesis method, spherical particles are formed having a particle size in the range of 11-30 nm and BET surface area of ~ $24m^2/g$. The degree of agglomeration of $SnO_2$ nanoparticles has been calculated.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1473-1476
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• 2008

Doping the nanoparticles of Pd, p-$BaTiO_3$, $SiO_2$ and MgO into LCs alters their physical properties such as $K_{ii}$, $\Delta\varepsilon$, ${\Delta}n$, $\gamma_1$ and $T_{NI}$. Except for $K_{33}$, all these parameters decreases and thus bring the reduction of operating voltage and/or response times.