• Title/Summary/Keyword: Carbon-carbon composite

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Dispersion of carbon nanotube in polymer composite and their field emission superiority

  • Park, J.H.;Jeon, S.Y.;Alegonkar, P.S.;Yoo, J.B.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.778-781
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    • 2007
  • The dispersion of carbon nanotubes in composite and their field emission superiority have been discussed. Four synthesis methods have been studied. The CNT-composite, synthesized by the combination of the chemical and mechanical dispersion routes shows superior dispersion as well as field emission characteristics as compared to other syntheses methods.

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Carbon/TiO2 Prepared from Anatase to Pitch and their Photocatalytic Performance

  • Chen, Ming-Liang;Ko, Young-Shin;Oh, Won-Chun
    • Carbon letters
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    • v.8 no.1
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    • pp.6-11
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    • 2007
  • Carbon/$TiO_2$ composites were prepared by $CCl_4$ solvent mixing method with different mixing ratios. Since the carbon layers derived from pitch on the $TiO_2$ particles were porous, the Carbon/$TiO_2$ composite series showed a good adsorptivity and photo decomposition activity. The BET surface area for the carbon layer in the sample increases to increasing with pitch contents. The SEM results present to the characterization of porous texture on the Carbon/$TiO_2$ composite and pitch distributions on the surfaces for all the materials used. From XRD data, a weak and broad carbon peak of graphene with pristine anatase peaks were observed in the X-ray diffraction patterns for the Carbon/$TiO_2$. The EDX spectra show the presence of C, O and S with strong Ti peaks. Most of these samples are richer in carbon and major Ti metal than any other elements. Finally, the excellent photocatalytic activity of Carbon/$TiO_2$ with slope relationship between relative concentration (C/$C_0$) of MB and t could be attributed to the homogeneous coated pitch on the external surface by $CCl_4$ solvent method.

Preparation and pH-Sensitive Release Behavior of Alginate/Activated Carbon Composite Magnetic Hydrogels

  • Han, Min-Hee;Yun, Ju-Mi;Lee, Young-Seak;Kim, Hyung-Il
    • Carbon letters
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    • v.11 no.2
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    • pp.122-126
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    • 2010
  • The alginate-based hydrogel was prepared as a pH-sensitive drug delivery system. To enhance the drug loading capacity, activated carbon was introduced as a drug absorbent. The iron oxide was incorporated into the alginate matrix for the magnetic transferring to the target organ. The activated carbon and iron-oxide were dispersed uniformly in the alginate hydrogel. The drug release from the alginate/activated carbon composite hydrogel was carried out in various pH conditions with vitamin B12 and Lactobacillus lamnosers as model drugs. The fast and sustainable release of drug was observed in the basic condition due to the pH-sensitive solubility of alginate. The novel drug delivery system having pH-sensitive release property and magnetic movement to target place was developed by using the alginate/activated carbon composite magnetic hydrogels.

Thermomechanical Properties of Carbon Fibres and Graphite Powder Reinforced Asbestos Free Brake Pad Composite Material

  • Thiyagarajan, P.;Mathur, R.B.;Dhami, T.L.
    • Carbon letters
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    • v.4 no.3
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    • pp.117-120
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    • 2003
  • Asbestos is being replaced throughout the world among friction materials because of its carcinogenic nature. This has raised an important issue of heat dissipation in the non-asbestos brake pad materials being developed for automobiles etc. It has been found that two of the components i.e. carbon fibres as reinforcement and graphite powder as friction modifier, in the brake pad material, can playa vital role in this direction. The study reports the influence of these modifications on the thermal properties like coefficient of thermal expansion (CTE) and thermal conductivity along with the mechanical properties of nonasbestos brake pad composite samples developed in the laboratory.

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Transient Thermoelastic Analysis and 3 Dimensional Stress Analysis of Carbon/Carbon Brake Disks (탄소/탄소 브레이크 디스크의 과도기 열탄성 해석과 3차원 응력해석)

  • 오세희;유재석;김천곤;홍창선;김광수
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2000.11a
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    • pp.147-152
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    • 2000
  • This paper presents the thermoelastic analysis and 3-D failure analysis of the carbon/carbon brake disk. The mechanical properties of the carbon/carbon brake disk were measured for both in-plane and out of plane directions. The mechanical properties were used as the input of the thermoelastic analysis and 3-D stress analysis for the brake disk. The gap between rotor clip and clip retainer was an important parameter in the loading transfer mechanism of the rotor. The change of gap was considered separating the mechanical deformation and thermal deformation. Because the rotor clip and clip retainers were not contacted, the clip retainers and rivets were excluded from the rotor analysis model. The disk was modeled by using the cyclic symmetry condition and the contact problem between the rotor disk and rotor clip was considered. From the results of the 3-D stress analysis, the stress concentration at the key hole of the brake disk was confirmed.

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Mechanical Properties of 3D Printed Composite Material on Various Thermal Environment (다양한 온도 환경에 따른 3D 프린트 복합재료의 기계적 물성 평가)

  • Sang-Hun Kang;Do-Hyeon Kim;Hyoung-Seock Seo
    • Composites Research
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    • v.36 no.3
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    • pp.193-198
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    • 2023
  • Currently, there are many discussions about composite materials and 3D printed composite material to weight reduction of ships. A test was conducted to confirm the applicability of the 3D printed composite material to ships and offshore structures by linking the 3D printing technology with excellent productivity and the composite material with corrosion resistance and lightweight characteristics in salt water environments. In order to apply the 3D printed composite material used in this paper to ships and offshore structures, the temperature environmental effects that can be exposed in the marine environment should be considered. Therefore, the tensile test was conducted with specimen of Carbon + Onyx, Carbon + Nylon, HSHT glass + Onyx, HSHT glass + Nylon material in low temperature (-50℃), room temperature (20℃), and high temperature (50℃) environments that can be exposed to the marine environment. As a result of the tensile test, the carbon + onyx specimen showed the highest tensile strength and the HSHT glass + onyx specimen showed the highest tensile strain. In addition, by analyzing the tested specimens, the failure mode of the 3D printed composite material specimens exposed to various temperature environments was analyzed.

Preparation of Amine-epoxy Adducts(AEA)/Thin Multiwalled Carbon Nanotubes (TWCNTs) Composite Particles using Dry Processes

  • Jung, Hyun-Taek;Cho, Young-Min;Kim, Tae-Ho;Kim, Tae-Ann;Park, Min
    • Carbon letters
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    • v.11 no.2
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    • pp.107-111
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    • 2010
  • We prepared the amine epoxy adducts (AEA)/thin multiwalled carbon nanotubes (TWCNTs) composite particles using nonsolvent based methods including dry mechano-chemical bonding(MCB) process and supercritical fluid (SCF) process. The resulting TWCNTs/AEA composite particles have been used as curing agents for urethane modified bispheol A type epoxy resin. The thermal, thermomechanical properties of the epoxy resins cured with TWCNTs/AEA composite particles were measured by DMA and the dispersion of CNT was characterized by SEM. Because of high degree of CNT dispersion, thermal and mechanical properties of the epoxy resin cured with TWCNTs/AEA composite particles prepared by SCF process are better than those cured with mechano-chemically prepared TWCNTs/AEA composite particles.

X-ray Photoelectron Spectroscopic Analysis of Modified MWCNT and Dynamic Mechanical Properties of E-beam Cured Epoxy Resins with the MWCNT

  • Lee, Young-Seak;Im, Ji-Sun;Yun, Seok-Min;Nho, Young-Chang;Kang, Phil-Hyun;Jin, Hang-Kyo
    • Carbon letters
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    • v.10 no.4
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    • pp.314-319
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    • 2009
  • The surface treatment effects of reinforcement filler were investigated based on the dynamic mechanical properties of mutiwalled carbon nanotubes (MWCNTs)/epoxy composites. The as-received MWCNTs(R-MWCNTs) were chemically modified by direct oxyfluorination method to improve the dispersibility and adhesiveness with epoxy resins in composite system. In order to investigate the induced functional groups on MWCNTs during oxyfluorination, X-ray photoelectron spectroscopy was used. The thermo-mechanical property of MWCNTs/epoxy composite was also measured based on effects of oxyfluorination treatment of MWCNTs. The storage modulus of MWCNTs/epoxy composite was enhanced about 1.27 times through oxyfluorination of MWCNTs fillers at $25^{\circ}C$. The storage modulus of oxyfluorinated MWCNTs (OF73-MWCNTs) reinforced epoxy composite was much higher than that of R-MWCNTs/epoxy composite. It revealed that oxygen content led to the efficient carbon-fluorine covalent bonding during oxyfluorination. These functional groups on surface modified MWCNTs induced by oxyfluorination strikingly made an important role for the reinforced epoxy composite.