• Title/Summary/Keyword: Composite particle

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Synthesis and Characterization of Al2O3/ZrO2, Al2O3/TiO2 and Al2O3/ZrO2/TiO2 Ceramic Composite Particles Prepared by Ultrasonic Spray Pyrolysis

  • Shim, In-Soo;Lee, Chang-Seop
    • Bulletin of the Korean Chemical Society
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    • v.23 no.8
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    • pp.1127-1134
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    • 2002
  • Fine ceramic particles of zirconia toughened alumina (ZTA), titania toughened alumina (TTA), and zirconia-titania toughened alumina (ZTTA) have been synthesized by ultrasonic spray pyrolysis (USP) at various temperatures from starting salt solutio ns of various compositions aiming for the development of catalytic material. These particles were characterized for properties such as shape, size and size distribution, diffraction pattern, and chemical and phase composition of elements by scanning electron microscopy (SEM), particle size analyzer (PSA), x-ray diffraction (XRD), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Chemical compositions and sizes of ceramic composites have been controled by the stoichiometry of salt solutions and the flow rate of spraying solutions. The optimum experimental conditions for the various composite particle syntheses have been proposed.

Manufacture of PMMA/PBA and PBA/PMMA core Shell Composite Particles - Effect of emulsifier - (PMMA/PBA와 PBA/PMMA Core Shell 복합입자의 제조 - 유화제의 영향 -)

  • Seul, Soo Duk
    • Journal of Adhesion and Interface
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    • v.11 no.3
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    • pp.112-119
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    • 2010
  • Poly(methyl methacrylate)/poly(butyl acrylate) PMMA/PBA core-shell composite particles were prepared by the emulsion polymerization of MMA and BA in the presence of different concentration of sodium dodecyl benzene sulfonate (SDBS). The following conclusions are drawn from the measured conversion and particle size distribution, morphology, average molecular weight distribution, observation of film formation and particle formation, glass transition temperature and physical properties of polymerized core-shell composition particles for using adhesive binder. When the concentration of 0.03 wt% surfactant, the conversions of PMMA and PBA core polymerization are excellent as 95.8% for PMMA core and 92.3% for PBA core. Core-shell composite particles are obtained 90.0% for PMMA/PBA core-shell composite particles and 89.0% for PMMA/PBA core-shell composite particles. It is considered that the core and shell particles are polymerized to be confirmed FT-IR spectra and average molecular weight measured with a GPC, formation of the composite particles is confirmed by the film formation from normal temperature, and composition of inside and outside of the composite particle is confirmed by TEM photograph. The synthesized polymer has two glass transition temperatures, suggesting that the polymer is composed of core polymer and shell polymer unlike general copolymers. It is considered that each core-shell composite particle can be used as a high functionality adhesion binder by the measurement of tensile strength and elongation.

Manufacture of Alkyl Acrylate Multi Core-shell Composite Particle (알킬 아크릴레이트계의 다중 Core-shell 복합입자의 제조)

  • Cho, Dae-Hoon;Choi, Sung-Il;Go, Hyun-Mi;Seul, Soo-Duk
    • Journal of Adhesion and Interface
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    • v.12 no.1
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    • pp.16-25
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    • 2011
  • Multi core-shell composite particles were prepared by the water-born emulsion polymerization of various core monomer such as methyl methacrylate (MMA), n-butyl methacrylate (BMA), and shell monomer such as MMA, BMA, stylene (St), 2-hydroxyl ethyl methacrylate (2-HEMA) and acrylic acid (AA) in the presence of different concentration of sodium dodecyl benzene sulfonate (SDBS). The following conclusions are drawn from the measured conversion, particle size and distribution, average molecular weight, molecular structure, glass transition temperature with DSC, morphology, tensile strength and elongation. In the case of the concentration of 0.02 wt% SDBS, the conversion of MMA core-(BMA/St/AA) shell composite particle was excellent as 98%. In the case of the concentration of 0.03 wt% SDBS, the particle size of BMA core-(MMA/St/AA) shell composite particle was high as $0.47{\mu}m$. We confirmed that 3 points of glass transition temperatures appear for multi core-shell composite particles compared to 2 points of glass transition temperatures appear for general core-shell composite particles. We showed that it is possible to adjust glass transition temperatures according to the kind and composition of the inner shell monomer that it is can be used as a adhesive binder material with improved adhesive power.

Synthesis and Effect of Plasma Treatment of Acrylic Composite Particle Binder (아크릴계 복합입자 바인더의 제조와 플라즈마 처리영향)

  • Sim, Dong-Hyun;Seul, Soo-Duk
    • Polymer(Korea)
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    • v.32 no.3
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    • pp.276-283
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    • 2008
  • Kind of monomer(MMA, EA, BA, St)and the monomer ratio(80/20 to 20/80) where changed in the preparation of the core shell binder, and property was improved the plasma processing. Each material changed by plasma treatment time($1{\sim}10\;s$) to change to measure the tensile strength, contact angle and adhesion peel strength for the core shell binder optimal conditions for handling the output of the surface treatment. The type of polymerization and composition of the binder is a regardless initiator of APS, the reaction temperature of $85^{\circ}C$ to 0.3 wt% of the surfactant used to indicate when the conversion rate was the highest, core shell composite particle binder got two glass temperature curves. Core shell binder after the plasma processing contact angle change is the PEA/PSt 38 percent of cases within five seconds to indicate slight decrease was a decline rapidly if not handled $0^{\circ}$ to reach. Tensile strength PSt/PMMA varies $46.71{\sim}46.27\;kg_f$/2.5 cm and adhesion strength PEA/PMMA varies $7.89{\sim}14.44\;kg_f$/2.5 cm increases. Overall, adhesion strength of core shell composite particle is in the order of order PEA>PBA>PSt for shell monomer MMA.

Surface Coating of SiO2 on TiO2-natural Zeolite Composite Particles and Its Characterization (실리카 코팅된 TiO2-천연 제올라이트 복합입자 제조와 특성평가)

  • Lim, Hyung-Mi;Jung, Ji-Sook;Lee, Dong-Jin;Lee, Seung-Ho
    • Korean Journal of Materials Research
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    • v.16 no.11
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    • pp.692-697
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    • 2006
  • Deodorization of natural zeolites have been improved not only for polar but also for non-polar pollutants by sucessive ion exchanges of H and Ag ions starting from Korean natural zeolite with high adsorption capacity. The modified zeolites with $TiO_2$ coating on the surface revealed high deodorization and photocatalytic decomposition effects. Further modification was made with $10{\sim}20nm$ silica nano particles coating on the surface, the resulting composite particles of $SiO_2/TiO_2/modified$ natural zeolite revealed not only comparable deodorization but also better durability and resisatnce to color change compared to the $TiO_2$/modified natural zeolite without much compensation of photocatalytic decomposition effect, when the composite particles were exposed to the polypropylene non-woven fiber coated with organic binder. It is expected for the composite particle prepared here to be used as indoor building materials for indoor air quality control.

Preparation and characteristics of modified Ni/YSZ cermet for high temperature electrolysis (고온 수전해 전극용 modified Ni/YSZ cermet 제조 및 전극특성)

  • Chae, Ui-Seok;Park, Geun-Man;Hong, Hyeon-Seon;Choo, Soo-Tae;Yun, Yongseung
    • Transactions of the Korean hydrogen and new energy society
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    • v.15 no.2
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    • pp.98-107
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    • 2004
  • Modified Ni/YSZ cermets for high temperature electrolysis were synthesized by dry or wet mechanical alloying methods. The Ni/YSZ composit particle was directly fabricated from the ball milling of Ni and YSZ powder or obtained from the reduction of NiO/YSZ particle after the ball milling of NiO and YSZ. In the case of the NiO/YSZ composite particle, the dry milling increased the average particle size whereas the wet milling decreased the size. The dry milling showed that fine YSZ particles were distributed over large Ni surfaces while Ni and YSZ particles similar in size were well mixed in the wet milling method. These features were the same in the Ni/YSZ composite particle prepared from Ni and YSZ powders. The electrical conductivity of the wet-milled Ni/YSZ cermet showed the highest value of $2{\times}10^2S/cm$ among the specimens and this value was increased to $1.4\times10^4S/cm$ after the sintering at $900^\circ{C}$ for 1 h.

Preparation and Characterization of Spherical Carbon Composite for Use as Anode Material for Lithium Ion Batteries

  • Ahn, Byoung-Hoon;Lee, Sung-Man
    • Bulletin of the Korean Chemical Society
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    • v.31 no.5
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    • pp.1331-1335
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    • 2010
  • A novel spherical carbon composite material, in which nanosized disordered carbons are dispersed in a soft carbon matrix, has been prepared and investigated for use as a potential anode material for lithium ion batteries. Disordered carbons were synthesized by ball milling natural graphite in air. The composite was prepared by mixing the ball-milled graphite with petroleum pitch powder, pelletizing the mixture, and pyrolyzing the pellets at $1200^{\circ}C$ in an argon flow. The ballmilled graphite consists of distorted nanocrystallites and amorphous phases. In the composite particle, nanosized flakes are uniformly distributed in a soft carbon matrix, as revealed by X-ray diffractometer (XRD) and transmission electron microscopy (TEM) experiments. The composite is compatible with a pure propylene carbonate (PC) electrolyte and shows high rate capability and excellent cycling performance. The electrochemical properties are comparable to those of hard carbon.

Preparation of Silica-Gold Composite particles (실리카-골드 복합체의 합성 연구)

  • Kim, Dae-Wook;Shim, Seung-Bo;Chun, Yong-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.11
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    • pp.5365-5369
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    • 2011
  • Silica-gold composite particles were prepared by wet chemical route including impregnation method. The effect of precursor and solvent on the preparation of silica-gold particles was investigated. When spherical silica particles and PVP and hydrogentetrachloroaurate(III) hydrate aqueous solution were used as support material and precursor solution, silica-gold composite particles with light pink color successfully obtained. Obtained composite particles were characterized using FE-SEM, FE-TEM and XRD.

Comparative Diagnostic Studies on Serologic and Molecular Biological Tests Against Haemorrhagic Fever with Renal Syndrome (신증후출혈열 환자의 혈청학적 및 분자생물학적 진단 검사법 비교)

  • 우영대;문희주;배형준
    • Biomedical Science Letters
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    • v.6 no.2
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    • pp.141-149
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    • 2000
  • The etiologic agents of haemorrhagic fever with renal syndrome (HFRS) in Korea are Hantaan and Seoul virus in the genus Hantavirus, family Bunyaviridae. Antibody titers of sera from HFRS patients against Hantaan virus were measured by immunofluorescent antibody technique (IFAT), enzyme-linked immunosorbent assay (ELISA), high density composite particle agglutination (HDPA) and plaque reduction neutralization test (PRNI). PRNT and nested reverse transcriptase polymerase chain reaction (nested RT-PCR) was used for serotypic differentiation of Hantaviruses against Hantaan and Seoul virus. Eight doubtful HFRS patients showed higher fluorescent, IgG ELISA, agglutination and neutralizing antibody titer by IFAT, ELISA IgG, HDPA and PRNT, respectively Five out of them showed high IgM antibody titer by IgM capture ELISA against Hantaan virus, remarkably. Fifteen HFRS patients showed higher fluorescent antibody titer by IFAT. In PRNT, 12 out of them showed high neutralizing antibody titer against HTNV, 2 against SEOV and 1 against both viruses. In nested RT-PCR using serotype specific-primer, 3 out of them showed positive against HTNV and 1 against SEOV.

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Thermal Plasma Synthesis of Nano Composite Particles (열플라즈마에 의한 복합 나노 입자 제조)

  • Jeong, Min-Hee;Kim, Heon-Chang
    • Applied Chemistry for Engineering
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    • v.21 no.6
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    • pp.676-679
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    • 2010
  • Nano composite particles were synthesized from a bulk ZrVFe alloy ingot by transferred DC thermal plasma. Effects of plasma gas flow rate on the characteristics of the produced nano composite particles were investigated. The characteristics of the synthesized powder were analyzed by field scanning electron microscopy (FE-SEM), light scattering particle size analyzer (PSA), energy dispersive X-ray spectroscopy (EDS), X-ray diffractometer (XRD), and Brunauer-Emmett-Teller (BET) surface area analyzer. As the flow rate of plasma gas increased from 20 L/min to 40 L/min, the average particle size decreased from 91 nm to 55 nm, the particle size distribution became narrower, the surface area increased from $200\;m^2/g$ to $255\;m^2/g$, the particle composition was nearly unaffected, and the particle crystallinity was improved.