• Title/Summary/Keyword: mesoporous carbon

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Thermal Insulation Properties of Epoxy/Mesoporous Carbon Composites

  • Heo, Gun-Young;Seo, Min-Kang;Oh, Sang-Yeob;Choi, Kyeong-Eun;Park, Soo-Jin
    • Carbon letters
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    • v.12 no.1
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    • pp.53-56
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    • 2011
  • This study aimed to investigate the influence of mesoporous carbons on the thermal insulation properties of epoxy/mesoporous carbon composites. The mesoporous carbon (CMK-3) was prepared by conventional templating method using SBA-15. The epoxy/mesoporous carbon composites were prepared by mixing the synthesized CMK-3 with diglycidylether of bisphenol A (DGEBA). As experimental results, the curing reactivities of the DGEBA/CMK-3 composites were found to decrease with the addition of the CMK-3. Also, the thermal conductivities of DGEBA/CMK-3 composites were found to decrease with increasing CMK-3 content. This could be interpreted in terms of the slow thermal diffusion rate resulting in pore volume existing in the gaps in the interfaces between the mesoporous carbon and the DGEBA matrix.

Synthesis and surface characterization of mesoporous carbon for the adsorption of methane gas (메탄가스 흡착을 위한 메조포러스 카본 합성과 표면 특성 연구)

  • Park, Sang-Won;Lee, Kamp-Du;Noh, Min-Soo
    • Journal of Environmental Science International
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    • v.22 no.7
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    • pp.837-845
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    • 2013
  • This study was designed to synthesize mesoporous carbon, porous carbonic material and to characterize its surface in an attempt to adsorption methane gas($CH_4$). Synthesis of mesoporous carbon was carried out under two steps ; 1. forming a RF-silica complex with a mold using CTMABr, a surfactant, and TEOS, raw material of silica, and 2. eliminating silica through carbonization and HF treatment. The mesoporous carbon was synthesized under various conditions of synthesis time and calcination. Eight different types of mesoporous carbon, which were designated as MC1, MC2, MC3, MC4, MCT1, MCT2, MCT3, and MCT4, were prepared depending upon preparation conditions. The analysis of mesoporous carbon characteristics showed that the calcination of silica stabilized the mixed structure of silica and carbonic complex, and made the particle uniform. The results also showed that hydrothermal synthesis time did not have a strong influence on the size of pore. The bigger specific surface area was obtained as the hydrothermal synthesis time was extended. However, the specific surface area was getting smaller again after a certain period of time. In adsorption experiments, $CH_4$ was used as adsorbate. For the case of $CH_4$, MCT3 showed the highest adsorption efficiency.

Synthesis of Ordered Mesoporous Manganese Oxides by Double Replication for Use as an Electrode Material

  • Guo, Xiao-Feng;Kim, Geon-Joong
    • Bulletin of the Korean Chemical Society
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    • v.32 no.1
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    • pp.186-190
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    • 2011
  • Periodically ordered mesoporous manganese oxides were synthesized in a single and double replication procedure. Mesoporous SBA-15 and -16 silica and their reverse replica carbons were successively used as hard templates. The silica and carbon pore systems were infiltrated with $Mn(NO_3)_2{\cdot}xH_2O$ or $Mn(AcAc)_2$, which was then converted to $Mn_2O_3$ at 873 K; the silica and carbon matrix were finally removed by NaOH solution or calcinations in air. The structure of the mesoporous $Mn_2O_3$, using a carbon template, corresponds to that of the original SBA-15 and SBA-16 silica. The products consist of hexagonally arranged cylindrical mesopores with crystalline pore walls or cubic mesoporous pores. The structure of replica has been confirmed by XRD, TEM analysis, and its electrochemical properties were tested with cyclic voltammetry. Formation of $Mn_2O_3$ inside the mesoporous carbon pore system showed much improved electrical properties.

Effect of Carbonization Temperature on Carbon Dioxide Adsorption Behaviors of mesoporous carbon (중기공 탄소의 탄화온도에 따른 이산화탄소 흡착 거동)

  • Jang, Dong-Il;Park, Soo-Jin
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.221.1-221.1
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    • 2011
  • In this study, we prepared the nitrogen-containing carbon spheres with mesopore processed by a facile polymerization-induced colloid aggregation method including carbonization in order to investigate the characterization and the effect on their carbon dioxide adsorption behaviors. The carbonization temperature was varied in the range of $600^{\circ}C$ to $900^{\circ}C$. The nitrogen contents of the mesoporous carbon sphere were characterized using XPS. The carbon dioxide adsorption capacities of the prepared mesoporous carbon sphere were determined by the amounts of carbon dioxide adsorptions at 298 K and 1.0 atm. The results showed that the prepared mesoporous carbons were highly effective for the carbon dioxide adsorption due to the increasing the affinity of the basic functionalities of adsorbent surface to acidic carbon dioxide. Maximum adsorption capacities of carbon dioxide at $25^{\circ}C$ were achieved up to 106 mg/g.

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Preparation of Mesoporous SiCBN Ceramic Templated by Mesoporous Carbon

  • Nghiem, Quoc Dat;Ryoo, Hyang-Im;Kim, Dong-Pyo
    • Journal of the Korean Ceramic Society
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    • v.44 no.7
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    • pp.358-361
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    • 2007
  • Well-ordered mesoporous SiCBN ceramics have been successfully synthesized by infiltrating a polymeric precursor, which was prepared from borazine and 2,4,6-trimethyl-2,4,6-trivinylcyclotrisilazane via a hydroboration reaction, into a mesoporous carbon (CMK-3) as a hard template. This was followed by pyrolysis at $1400^{\circ}C$ under nitrogen gas and subsequent oxidative removal of the carbon template without chemical etching. The prepared mesoporous SiCBN ceramic was characterized by a small-angle XRD, TEM, and BET surface area. The resulting mesoporous SiCBN ceramic revealed a BET surface area of $275 m^2g^{-1}$ and a pore volume of $0.8 cm^3 g$ with no crystallization.

Synthesis of Hollow Mesoporous Carbon Nitride Spheres Using Polystyrene Spheres as Template (폴리스티렌 구형입자를 주형으로 이용한 할로우 메조포러스 질화탄소 구형입자의 합성)

  • Park, Sung Soo;Ha, Chang-Sik
    • Journal of Adhesion and Interface
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    • v.15 no.2
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    • pp.63-68
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    • 2014
  • Hollow mesoporous carbon nitride material with sphere shape was synthesized using polystyrene sphere as template and cyanamide as nitrogen and carbon atom sources via thermal treatment process. The process of the silica removal is not necessary because silica as template is not in use for the synthesis of hollow mesoporous carbon nitride material and any solvents are also not in use. The size of polystyrene spheres was about 170 nm. Hollow diameter and wall thickness were 82 nm and 13 nm, respectively, in hollow mesoporous carbon nitride sphere. Surface area, mesopore size and pore volume of hollow mesoporous carbon nitride material was $188m^2g^{-1}$, 3.8 nm and $0.35cm^3g^{-1}$, respectively. The wall in hollow sphere has graphitic structure. Hollow mesoporous carbon nitride material has potential applications in the area of fuel cell, catalysis, photocatalysis, electroemmision device, etc.

Fabrication of CNT/CMK3 Carbon Composites with High Electrical/Thermal Conductive Properties

  • Choi, Seung Dae;Lee, Ju Hyun;Park, Da Min;Kim, Geon-Joong
    • Bulletin of the Korean Chemical Society
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    • v.34 no.7
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    • pp.2155-2161
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    • 2013
  • Composite materials of mesoporous carbon and carbon nanotubes were synthesized using Ni, Co and Pd-loaded CMK3 via a catalytic reaction of methane and $CO_2$. The CNTs grew from the pores of the mesoporous carbon supports, and they were attached tightly to the CMK3 surface in a densely tangled shape. The CNT/CMK3 composite showed both non-graphitic mesoporous structures, and graphitic characteristics originating from the MWCNTS grown in the pores of CMK3. The electrochemical properties of the materials were characterized by their electrorheological effects and cyclic voltammetry. The CNTs/CMK3 composites showed high electrical conductivity and current density. The CNT/CMK3 or KOH-modified CNT/CMK3 particles were incorporated in a PMMA matrix to improve the thermal and electrical conductivity. Even higher thermal conductivity was achieved by the addition of KOH-modified CNT/CMK3 particles.

Preparation of mesoporous carbon using ion exchange (이온 교환을 이용한 메조기공 활성탄의 제조)

  • Lee, Jong-Dae;Kang, Chae-Yoen;Kang, Min-Goo
    • Journal of the Korean Applied Science and Technology
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    • v.26 no.3
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    • pp.328-334
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    • 2009
  • Recently, much interest on mesoporous carbon has been shown in their use for both hydrogen and methane storage and as an electrode material for electric double layer capacitors. The mesoporous active carbons by ion exchange were prepared and physical properties such as specific surface area and pore structure of active carbon were investigated using BET. In this study, active carbons with mesopore fraction of $60{\sim}90%$ were obtained. The Fe/Ca-exchanged active carbons showed a greater mesoporosity compared with Fe-exchanged carbons. The mean mesopore size in active carbons using Ca- and Fe-exchange was about $5.5{\sim}6.0nm$ and was approximately 1nm higher than that of the Fe-exchanged active carbon.

Fabrication of Mesoporous Carbon Nanofibers for Electrical Double-Layer Capacitors (전기 이중층 커패시터용 메조 다공성 탄소 나노섬유의 제조)

  • Lee, Do-Young;An, Geon-Hyoung;Ahn, Hyo-Jin
    • Korean Journal of Materials Research
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    • v.27 no.11
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    • pp.617-623
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    • 2017
  • Mesoporous carbon nanofibers as electrode material for electrical double-layer capacitors(EDLCs) are fabricated using the electrospinning method and carbonization. Their morphologies, structures, chemical bonding states, porous structure, and electrochemical performance are investigated. The optimized mesoporous carbon nanofiber has a high sepecific surface area of $667m^2\;g^{-1}$, high average pore size of 6.3 nm, and high mesopore volume fraction of 80 %, as well as a unifom network structure consiting of a 1-D nanofiber stucture. The optimized mesoporous carbon nanofiber shows outstanding electrochemical performance with high specific capacitance of $87F\;g^{-1}$ at a current density of $0.1A\;g^{-1}$, high-rate performance ($72F\;g^{-1}$ at a current density of $20.0A\;g^{-1}$), and good cycling stability ($92F\;g^{-1}$ after 100 cycles). The improvement of the electrochemical performance via the combined effects of high specific surface area are due to the high mesopore volume fraction of the carbon nanofibers.

Synthesis of Mesostructured Conducting Polymer-Carbon Nanocomposites and Their Electrochemical Performance

  • Choi, Moon-Jung;Lim, Byung-Kwon;Jang, Jyong-Sik
    • Macromolecular Research
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    • v.16 no.3
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    • pp.200-203
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    • 2008
  • A conducting polymer layer was introduced into the pore surface of mesoporous carbon via vapor infiltration of a monomer and subsequent chemical oxidative polymerization. The polypyrrole, conducting polymer has attracted considerable attention due to the high electrical conductivity and stability under ambient conditions. The mesoporous carbon-polypyrrole nanocomposite exhibited the retained porous structure, such as mesoporous carbon with a three-dimensionally connected pore system after intercalation of the polypyrrole layer. In addition, the controllable addition of pyrrole monomer can provide the mesoporous carbon-polypyrrole nanocomposites with a tunable amount of polypyrrole and texture property. The polypyrrole layer improved the electrode performance in the electrochemical double layer capacitor. This improved electrochemical performance was attributed to the high surface area, open pore system with three-dimensionally interconnected mesopores, and reversible redox behavior of the conducting polypyrrole. Furthermore, the correlation between the amount of polypyrrole and capacitance was investigated to check the effect of the polypyrrole layer on the electrochemical performance.