• 제목/요약/키워드: Flame Synthesis

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Synthesis of Carbon-Supported Pt-Ru Catalysts using a Flame Spray Pyrolysis Method for Fuel Electrode of Low Temperature Fuel Cell (화염분무열분해 공정을 이용한 저온 연료전지 연료전극용 탄소담지 Pt-Ru 촉매의 제조)

  • Lee, Hyun-Min;Lee, Dong-Geun
    • Particle and aerosol research
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    • v.8 no.2
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    • pp.69-74
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    • 2012
  • This study describes how successfully a conventional flame aerosol synthesis was used to continuously synthesize Pt-Ru catalysts supported by carbon agglomerates. Nearly spherical catalysts produced in the flame were mainly composed of metallic Pt and Ru with the molar ratio of 1:1 and those sizes were controllable from ~1.5 nm to ~2.0 nm. Nevertheless, only Pt peaks were found from X-ray diffraction experiments, suggesting that amorphous-like Ru was well mixed in the crystalline Pt lattices. It was found from Cyclo-voltamograms and CO stripping experiments that the electrochemical properties of the catalysts are at least comparable to that of a conventional commercial sample.

Synthesis of Carbon Nanotubes and Nanofibers on a Substrate Coated with Metal Nitrates using an C2H4 Inverse Diffusion Flame (메탈나이트레이트가 도포된 기판과 C2H4 역확산화염을 이용한 탄소나노튜브 및 탄소나노섬유의 합성)

  • Lee, Gyo-Woo;Jurng, Jong-Soo;Hwang, Jung-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.10
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    • pp.1480-1488
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    • 2003
  • Synthesis of carbon nanomaterials on a substrate coated with metal nitrates using an ethylene fueled inverse diffusion flame was illustrated. The effects of radial distance, residence time of the substrate, and hydrocarbon composition on the synthesis of carbon nanomaterials were investigated. The effects of catalyst metal particles were also studied using SUS304 substrates coated with Fe(NO$_3$)$_3$ (ferric nitrate, nonahydrate) and Ni(NO$_3$)$_2$(nickel nitrate, hexahydrate), and Cu substrate. Carbon nanomaterials, with diameters ranging from 30 - 70 nm, were observed on the substrate for both cases of using substrates only and using them with metal nitrates. In case of using the substrate with metal nitrates, the formation and growth of carbon nanomaterials were occurred in the lower temperature region than that of using the substrates only due to the easy activation of the metal particles coated on the surface of the substrates.

Effects of Flame Temperature on the Characteristics of Flame Synthesized $TiO_{2}$ Nanoparticles (화염온도에 따른 $TiO_{2}$ 나노입자의 결정구조 및 입자크기 변화)

  • Lee, Gyo-Woo;Jurng, Jong-Soo;Bae, Gwi-Nam
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1347-1352
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    • 2004
  • In this work, $TiO_{2}$ nanoparticles were synthesized using a $N_{2}-diluted$ hydrogen coflow diffusion flame. The effect of flame temperature on the crystalline structure and the size of formed nanoparticles was investigated. The maximum centerline temperature of the flame ranged from 1,920K for $H_{2}-only$ flame to 863K for 81% $N_{2}-diluted$ flame. When the temperature was higher than about 1,000K, the particle size was tend to increase due to the agglomeration and sintering among the primary particles. On the other hand, when the temperature was lower than 1,000K, the portion of anatase phase was greater than 80%.

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Synthesis of Flame Retardants for ABS using Cyclophosphazene (Cyclophosphazene을 이용한 ABS용 난연제의 합성)

  • Shin, Young-Jae;Kim, Hae-Young;Shin, Jae-Sup
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.2
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    • pp.142-151
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    • 2007
  • Non-halogen flame retardant have been focus of extensive research because of environmental problem. Hexakisphenokycyclotriphosphazene was synthesized in order to use as the flame retardant of ABS resin. And using bisphenol A, bisphenol S, and resorcinol, the polymers which contained cyclophosphazene structure were synthesized in order to also use as the flame retardants of ABS resin. All of the synthesized polymers themselves got the excellent flame retardancy. And as the molecular weight of the compound were increased, the thermal stability was increased. But when the synthesized compounds were used as the flame retardants for ABS resin, the lower molecular weight compound in these compounds showed the better flame retardancy and the better physical properties of ABS resin. In case of using resorcinol, it showed the best flame retardancy.

Pt Coating on Flame-Generated Carbon Particles (화염법을 이용한 Pt/C 촉매 제조)

  • Choi, In-Dae;Lee, Dong-Geun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.2
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    • pp.116-123
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    • 2009
  • Carbon black, activated carbon and carbon nanotube have been used as supporting materials for precious metal catalysts used in fuel cell electrodes. One-step flame synthesis method is used to coat 2-5nm Pt dots on flame-generated carbon particles. By adjusting flame temperature, gas flow rates and resident time of particles in flame, we can obtain Pt/C nano catalyst-support composite particles. Additional injection of hydrogen gas facilitates pyrolysis of Pt precursor in flame. The size of as-incepted Pt dots increases along the flame due to longer resident time and sintering in high temperature flame. Surface coverage and dispersion of the Pt dots is varied at different sampling heights and confirmed by Transmission electron microscopy (TEM), Energy-dispersive spectra (EDS) and X-ray diffraction (XRD). Crystalinity and surface bonding groups of carbon are investigated through X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy.

Synthesis of (2,3-Dibromopropyl)Phenyl Lauroyl Phosphate and Its Application as Emulsified Flame Retardant ((2, 3-Dibromopropyl)Phenyl Lauroyl Phosphate 합성과 유화난연제로서의 응용)

  • Park, Hong-Soo;Pyoun, Moo-Sil
    • Journal of the Korean Applied Science and Technology
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    • v.7 no.2
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    • pp.63-69
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    • 1990
  • (2,3-Dibromopropyl) phenyl lauroyl phosphate[DPPL] was synthesized by adding lauric acid to (2,3-dibromopropyl)chloro phenyl phosphate [DPP]. which prepared from phenyl phosphoric acid dichloride with 2,3-dibromo propyl alcohol. Flame retardants of DPPF and DPPLF were prepared respectively. DPPF was a water soluble flame retardant, and DPPLF was o/w type emulsion flame retardant. After flame retardant treating two kinds of flame retardants to the various synthetic fabrics respectively. the flame retardancy and tear strength were measured. As the results of the measurement. DPPF had only name retardancy, but DPPLF had both of flame retardancy and softness.

Effect of Flame Temperature on the Characteristics of the Combustion Synthesized $TiO_2$ Nanoparticles (연소합성된 $TiO_2$ 나노입자의 입자특성에 대한 화염온도 변화의 영향)

  • Lee, Gyo-Woo
    • Journal of the Korean Society of Combustion
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    • v.11 no.1
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    • pp.11-18
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    • 2006
  • In this work, $TiO_2$ nanoparticles were synthesized using $N_2-diluted$ and Oxygen-enriched coflow hydrogen diffusion flames. The effect of flame temperature on the characteristics of the formed $TiO_2$ nanoparticles was investigated. The measured maximum centerline temperature of the flame ranged from 2,103 K for oxygen-enriched flame to 1,339 K for $N_2-diluted$ flame. The visible flame length and the height of the main reaction zone were characterized by direct photographs. The characteristics of synthesized $TiO_2$ nanoparticles were analyzed by SEM and TEM images. From these images, it was evident that the formed nanoparticles were divided into two sorts. In the higher temperature region, over the 1,700 K, $TiO_2$ nanoparticles having spherical shapes with diameters about 60 nm were synthesized. In the lower temperature region, below the 1,600 K, the diameters of formed nanoparticles having unclear boundaries were ranged from 35 - 50 nm.

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Synthesis of (2, 3-Dibromopropyl)Phenyl Octadecanoyl Phospate and Its Application as Softening Flame Retardant ((2,3-Dibromopropyl)Phenyl Octadecanoyl Phosphate 합성과 유연난연제로서의 응용)

  • Park, Hong-Soo
    • Applied Chemistry for Engineering
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    • v.3 no.4
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    • pp.670-677
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    • 1992
  • (2, 3-Dibromopropyl) phenyl phosphate[DPP] was synthesized from 2, 3-dibromopropyl alcohol and chlorophenyl phosphate. Also, (2, 3,-dibromopropyl)phenyl octadecyl phosphate[DPOP] was synthesized from DPP and n-octadecyl chloride. Flame retardants, DPPF and DPOPF, were prepared by blending DPP and DPOP with emulsifier, respectively. The flame retardants prepared were o/w(oil in water) type emulsion flame retardants. As a result of treatments of the flame retardants on various synthetic textiles, DPPF showed only good flame retardancy, but DPOPF showed both good flame retardancy and good softness.

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Effect of Oxygen-Enriched Flame Temperature on the Crystalline Structures of the Flame-Synthesized TiO2 Nanoparticles (산소부화를 통한 화염온도 변화에 따른 연소합성된 TiO2 나노입자의 결정구조 변화)

  • Lee Gyo-Woo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.30 no.7 s.250
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    • pp.692-699
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    • 2006
  • In this work, $TiO_2$ nanoparticles were synthesized using $N_2-diluted$ and Oxygen-enriched co-flow hydrogen diffusion flames. The effect of flame temperature on the crystalline structure of the formed $TiO_2$ nanoparticles was investigated. The measured maximum centerline temperature of the flame ranged from 2,103k for oxygen-enriched flame to 1,339K for $N_2-diluted$ flame. The visible flame length and the height of the main reaction zone were characterized by direct photographs. The crystalline structures of $TiO_2$ nanoparticles were analyzed by XRD. From the XRD analysis, it was evident that the crystalline structures of the formed nanoparticles were divided into two sorts. In the higher temperature region, over the 1,700K, the fraction of formed $TiO_2$ nanoparticles having anatase-phase crystalline structure increased with increasing the flame temperature. On the contrary, in the lower temperature region, below the 1,600K, the fraction of anatase-phase nanoparticles increased with decreasing the flame temperature.

Effects of the Distribution of Nickel-Nitrate and the Substrate Temperature on the Synthesis of Multi-Walled Carbon Nanotubes (기판 상에 합성한 탄소나노튜브의 성장에 미치는 촉매금속 입자의 분포와 기판온도의 영향)

  • Lee, Gyo-Woo;Jung, Jong-Soo;Hwang, Jung-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.2
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    • pp.215-222
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    • 2004
  • Synthesis of multi-walled carbon nanotubes on a nickel-nitrate-deposited substrate using an ethylene fueled inverse diffusion flame was illustrated. The deposition of nickel-nitrate particles on substrates was used for the smaller-diameter nanotubes than those formed in our previous studies. Also the effect of temperature variations on the size of formed nanotubes was investigated. The diameters of formed multi-walled carbon nanotubes were ranging from 15 to 100 nm in the several radial locations. In case of using a nickel-nitrate-deposited substrate, the smaller-diameter carbon nanotubes were synthesized than those in case of using the substrate with melted nickel-nitrate. In the formation region of carbon nanotubes, the diameter of formed nanotubes was tend to be decrease as the radial distance form the flame center was increased, that is the decreased substrate temperature.