• 제목/요약/키워드: nano-morphology

검색결과 674건 처리시간 0.032초

인버스 확산화염에서의 나노 수트 입자 생성 (Nano-Soot Particle Formation in Inverse Diffusion Flames)

  • 이의주;신현준;오광철;신현동
    • 한국연소학회:학술대회논문집
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    • 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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    • pp.19-26
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    • 2003
  • Experimental measurements of flame structure and soot characteristics were performed for ethene inverse diffusion flames (IDF). IDF has been considered as the excellent flow field to study the incipient soot because soot particle do not experience the oxidation process. In this study, LIF image clarified the reaction zone of IDF with OH signal and PAH distribution. laser light scattering technique also identified the being of soot particle. To address the degree of soot maturing, C/H ratio and morphology of soot sample were investigated. From these measurements, the effect of flow residence time and temperature on soot inception could be suggested, and more details on soot characteristic in the IDF was determined according to fuel dilution and flame condition. The fuel dilution results in a decrease of temperature and enhancement of residence time, but the critical dilution mole fraction is existed for temperature not to effect on soot growth. Also, the soot inception evolved on the specific temperature and its morphology are independent of the fuel dilution ratio of fuel.

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Nanoscale Morphology of Bis(1-anthraquinoxy)glycols

  • Kwon, Soon-Sik;Liang, Hui;Kim, Jong-Pil;Lee, Young-A;Jung, Ok-Sang
    • Bulletin of the Korean Chemical Society
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    • 제28권11호
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    • pp.2065-2068
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    • 2007
  • The nanoscale morphologies on a series of new anthraquinone substitutes have been carried out. Among the substitutes, only bis[2-(1-anthraquinonoxy)-ethyl]ether in a mixture of dichloromethane/acetone (1/1) slowly forms uniform nanowires with 80-120 nm diameters. The same compound in a mixture of dichloromethane/tetrahydrofuran (1/1) slowly produces uniform nanobelts with 400-600 nm widths. Thus, both the spacer lengths and the solvent effects of the compounds are important factors for the formation of nanoscale morphologies. The nano patterns seem to be formed by the π-π interactions between the anthraquinone moieties.

Nanotube Morphology Change of Ti-Ta-Zr Alloy as Zr Content

  • Kim, Won-Gi;Choe, Han-Cheol;Ko, Yeong-Mu
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2008년도 추계학술대회 초록집
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    • pp.105-106
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    • 2008
  • Nanotube morphology change of Ti-Ta-Zr alloy as Zr content increase has been researched using various experimental methods. Ti-Ta-Zr(3, 7 and 15 wt%) alloys were prepared by arc melting and nano-structure controlled for 24 hr at $1000^{\circ}C$ in argon atmosphere. Formation of oxide nanotubes are conducted by anodizing a Ti-Ta-Zr alloy in $H_3PO_4$ electrolytes with small amounts of fluoride ions at room temperature. Electrochemical experiments were carried out with conventional three-electrode configuration with a platinum counter electrode and a saturated calomel reference electrode. The samples were embedded with epoxy resin, leaving a square surface area of $10mm^2$ exposed to the anodizing electrolyte, 1.0M $H_3PO_4$ containing 0.8wt% NaF.

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기능성 덴드리머 유기단분자막의 분자계면제어 및 분자모폴로지 특성 (Molecular Interfacial Control and Molecular Morphology Properties of Functionalized Dendrimer Organic Monolayers)

  • 신훈규;김두석
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.365-366
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    • 2007
  • The dendrimer has been well known as a promising macromolecules for a building the organized nanostructure, which of the size can be controlled and which of periphery can be terminated by various functionalities. Currently a variety of research is being carried out in the field of dendrimer / polymer characterization, nano-scale atomic manipulation, and supramolecular nanostructure analysis. We investigated monolayer behavior and its characteristics at the air-water interface by LB method. In this report, we will present the interfacial properties of dendrimer monolayers on various conditions such as the surface-pressure, barrier speed and spreading quantity.

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Studies on Properties of Polyaniline-Dodecylbenzene Sulfonic Acid Composite Films Synthesized Using Different Oxidants

  • Basavaraja, C.;Pierson, R.;Huh, Do-Sung;Venkataraman, A.;Basavaraja, S.
    • Macromolecular Research
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    • 제17권8호
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    • pp.609-615
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    • 2009
  • Two types of nano composite were obtained by in situ chemical method in polyaniline (PANI)/dodecyl-benzenesulfonic acid (DBSA) system depending on the use of either ammonium persulfate (APS) or ferric chloride ($FeCl_3$) as the oxidant. In order to study the difference of the two composites in the surface characteristics, thermal stability, and electric properties, the composite films were studied by transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and temperature dependent DC electrical conductivity. The results revealed a large difference in the surface morphology, thermal stability, and the microstructure properties between the two composites, and these differences were considered responsible for the molecular order and conductivity.

유화확산법을 이용한 피톤치드오일 함유 폴리입실론카프로락톤 나노캡슐의 제조와 성질(1) (Preparation and Properties of Poly($\varepsilon$-caprolactone) Nanocapsules Containing Phytoncide Oil by Emulsion-diffusion Method(1))

  • Jeong, Cheon-Hee;Kim, Hea-In;Park, Soo-Min
    • 한국염색가공학회:학술대회논문집
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    • 한국염색가공학회 2008년도 제38차 학술발표대회
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    • pp.114-116
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    • 2008
  • Poly(${\varepsilon}$-caprolactone) nanocapsules(nanoPCL) containing phytoncide oil were synthesized by emulsion diffusion method using ethyl acetate as organic solvent. The influence of the degree of hydrolyzation of poly(vinyl acohol) used as an emulsion stabilizer, and the different weight ratio of core material to wall material on the particle size, morphology, and emulsion stability was investigated to design nanocapsules. The encapsulated nanoPCL were characterized by FT-IR spetrometry, Scanning electron microscope, Differential scanning calorimetry, and Thermogravimetry analysis, respectively.

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The geometry change of carbon nanofilaments by SF6 incorporation in a thermal chemical vapor deposition system

  • Kim, Sung-Hoon
    • 한국결정성장학회지
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    • 제21권3호
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    • pp.119-123
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    • 2011
  • Carbon nanotilaments (CNFs) could be synthesized on nickel catalyst layer-deposited silicon oxide substrate using $C_2H_2$ and$H_2$ as source gases under thermal chemical vapor deposition system. By the incorporation of $SF_6$ as a cyclic modulation manner, the geometries of carbon coils-related materials, such as nano-sized coil and wave-like nano-sized coil could be observed on the substrate. The characteristics (formation density and morphology) of as-grown CNFs with or without $SF_6$ incorporation were investigated. Diameter size reduction for the individual CNFs-related shape and the enhancement of the formation density of CNFs-related material could be achieved by the incorporation of $SF_6$ as a cyclic modulation manner. The cause for these results was discussed in association with the slightly increased etching ability by $SF_6$ addition and the sulfur role in SF 6 for the geometry change.

Synthesis and electrochemical analysis of Pt-loaded, polypyrrole-decorated, graphene-composite electrodes

  • Park, Jiyoung;Kim, Seok
    • Carbon letters
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    • 제14권2호
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    • pp.117-120
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    • 2013
  • In this study, an electro-catalyst of Pt nanoparticles supported by polypyrrole-functionalized graphene (Pt/PPy-reduced graphene oxide [RGO]) is reported. The Pt nanoparticles are deposited on the PPy-RGO composite by chemical reduction of H2PtCl6 using NaBH4. The presence of graphene (RGO) caused higher activity. This might have been due to increased electro-chemically accessible surface areas, increased electronic conductivity, and easier charge-transfer at polymer-electrolyte interfaces, allowing higher dispersion and utilization of the deposited Pt nano-particles. Microstructure, morphology and crystallinity of the synthesized materials were investigated using X-ray diffraction and transmission electron microscopy. The results showed successful deposition of Pt nano-particles, with crystallite size of about 2.7 nm, on the PPy-RGO support film. Catalytic activity for methanol electro-oxidation in fuel cells was investigated using cyclic voltammetry. The fundamental electrochemical test results indicated that the electro-catalytic activity, for methanol oxidation, of the Pt/PPy-RGO combination was much better than for commercial catalyst.

Electrosynthesis and Electrochemical Properties of Metal Oxide Nano Wire/ P-type Conductive Polymer Composite Film

  • Siadat, S.O. Ranaei
    • Journal of Electrochemical Science and Technology
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    • 제6권3호
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    • pp.81-87
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    • 2015
  • This study introduces a facile strategy to prepare metal oxide/conducting polymer nanocomposites that may have promising applications in energy storage devices. Ploy aniline/nano wire manganese dioxide (PANI/NwMnO2) was synthesized by cyclic voltammetry on glassy carbon electrode. Morphology and structure of the composite, pure PANI, MnO2 nanowires were fully characterized using XRD and SEM analysis. Electrochemical studies shows excellent synergistic effect between PANI and MnO2 nanowires which results in its capacitance increase and cycle stability against PANI electrode. Specific capacitances of PANI/NwMnO2 and PANI were 456 and 190 F/g respectively. The electrochemical performance of electrodes studied using cyclic voltammetry, Galvanostatic charge/discharge and impedance spectroscopy.

Precipitation Behaviors of Hydroxyapatite on Highly Ordered Nanotubular Ti-35Ta-xNb Alloy Surface

  • Jo, Chae-Ik;Eun, Sang-Won;Choe, Han-Cheol
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2013년도 춘계학술대회 논문집
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    • pp.81-82
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    • 2013
  • In this study, precipitation behaviors of hydroxyapatite on highly ordered nanotubular Ti-35Ta-xNb alloy surface were researched. Ta and Nb additions to Ti increased corrosion resistance. The surface characteristics of anodized alloy depended on the nanotube formed voltage and alloy element. The HA precipitation morphology was influenced by nanorubular structure of alloys.

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