• Title/Summary/Keyword: Meso-porous

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Manufacturing of active carbon used city waste (도시쓰레기를 이용한 활성탄의 제조)

  • Sang, Hie-sun;Tamon, Hajime
    • Journal of the Korean Society of Industry Convergence
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    • v.9 no.1
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    • pp.87-91
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    • 2006
  • This research exposes the process of carbonization of solid waste from the city and the method of activated, as well as the process of meso-porous under several test conditions. In addition, it is expected that the active carbon obtained through this process can be used as filter for air and sewage treatment, and can absorb dioxin(as almost 60-80% of meso-porous and porous properties area) unlike the existing active carbon.

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Highly Ordered Porous Silica Adsorbent with Dual Pore Size Regime for Bulky VOC Gas Sensing

  • Yun, Ji Sun;Jeong, Young Hun;Nam, Joong-Hee;Cho, Jeong-Ho;Paik, Jong-Hoo
    • Journal of Sensor Science and Technology
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    • v.22 no.3
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    • pp.181-184
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    • 2013
  • Highly ordered porous materials having mesopores in the walls of macropores showed improved adsorption dynamics results for VOC molecules, especially bulky molecules. These meso/macroporous mataerials were synthesized by the dual templating method, and mesopore and macropore size were controlled by adjusting the templates for each pore size regime. In the case of adsorption and desorption of small VOC molecules (toluene), although meso/macroporous MCM-41 with smaller mesopore size showed improved results, meso/macroporous SBA-15 with larger mesopore size was not improved regardless of the existence of macropores, since there was no limitation of movement through the larger mesopore. However, the adsorption dynamics of bulky VOC molecules (p-xylene) over meso/macroporous SBA-15 were drastically improved by increasing the macropore size.

Preparation of Micro-spherical Activated Carbon with Meso-porous Structure for the Electrode Materials of Electric Double Layer Capacitor (전기이중층 캐패시터 전극용 meso-pore구조의 미소구형 활성탄소 제조)

  • Um, Eui-Heum;Lee, Chul-Tae
    • Applied Chemistry for Engineering
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    • v.20 no.4
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    • pp.396-401
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    • 2009
  • A micro-spherical activated carbon with meso-pore structure of 52~64% and particle diameter of $2{\sim}10{\mu}m$ was prepared for the improvement electrochemical performance of activated carbon as electrode material for electric double layer capacitor. Resorcinol-formaldehyde resin was used as a carbon source in this preparation. According to electrochemical analysis of EDLC using this activated a carbon with showing effects to reduce charge transfer resistance and to increase rate capability, it was found out that micro-spherical activated carbon could be a good method as well as a material for enhancing the performance of electric double layer capacitor.

Application of Hierarchically Porous Fe2O3 Nanofibers for Anode Materials of Lithium-ion Batteries (계층적 다공구조를 갖는 Fe2O3 나노섬유의 리튬 이차전지 음극소재 적용)

  • Jo, Min Su;Cho, Jung Sang
    • Korean Chemical Engineering Research
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    • v.57 no.2
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    • pp.267-273
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    • 2019
  • Hierarchically porous $Fe_2O_3$ nanofibers with meso- and macro- pores are designed and synthesized by electrospinning and subsequent heat-treatment. The macro pores are generated by selectively decomposition of polystyrene as a dispersed phase in the as-spun fibers containing $Fe(acac)_3$/polyacrylonitrile continuous phases during heat-treatment. Additionally, meso-pores formed by evaporation of infiltrated water vapor during electrospinning process interconnected the macro-pores and results in the formation of hierarchically porous $Fe_2O_3$ nanofibers. The initial discharge capacity and Coulombic efficiency of the hierarchically porous $Fe_2O_3$ nanofibers at a current density of $1.0A\;g^{-1}$ are $1190mA\;h\;g^{-1}$ and 79.2%. Additionally, the discharge capacity of the nanofibers is $792mA\;h\;g^{-1}$ after 1,000 cycles. The high structural stability and morphological benefits of the hierarchically porous $Fe_2O_3$ nanofibers resulted in superior lithium ion storage performance.

Interconnected meso/microporous carbon derived from pumpkin seeds as an efficient electrode material for supercapacitors

  • Gopiraman, Mayakrishnan;Saravanamoorthy, Somasundaram;Kim, Seung-Hyun;Chung, Ill-Min
    • Carbon letters
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    • v.24
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    • pp.73-81
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    • 2017
  • Interconnected meso/microporous activated carbons were prepared from pumpkin seeds using a simple chemical activation method. The porous carbon materials were prepared at different temperatures (PS-600, PS-700, PS-800, and PS-900) and demonstrated huge surface areas ($645-2029m^2g^{-1}$) with excellent pore volumes ($0.27-1.30cm^3g^{-1}$). The well-condensed graphitic structure of the prepared activated carbon materials was confirmed by Raman and X-ray diffraction analyses. The presence of heteroatoms (O and N) in the carbon materials was confirmed by X-ray photoemission spectroscopy. High resolution transmission electron microscopic images and selected area diffraction patters further revealed the porous structure and amorphous nature of the prepared electrode materials. The resultant porous carbons (PS-600, PS-700, PS-800, and PS-900) were utilized as electrode material for supercapacitors. To our delight, the PS-900 demonstrated a maximum specific capacitance (Cs) of $303F\;g^{-1}$ in 1.0 M $H_2SO_4 $ at a scan rate of 5 mV. The electrochemical impedance spectra confirmed the poor electrical resistance of the electrode materials. Moreover, the stability of the PS-900 was found to be excellent (no significant change in the Cs even after 6000 cycles).

Evaluation of Removal Characteristics of Taste and Odor Causing Compounds using Meso-Porous Absorbent (메조공극 흡착제를 이용한 상수원수내 맛·냄새 유발물질 제거특성 평가)

  • Kim, Jong-Doo;Park, Chul-Hwi;Yun, Yeo-Bog;Lee, Dae-Sung;Kim, Hyo-Jeon;Kang, Seok-Tae
    • Journal of Korean Society of Environmental Engineers
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    • v.39 no.1
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    • pp.26-33
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    • 2017
  • The objective of this study was to evaluate the characteristic of adsorption by using a meso-porous adsorbent (MPA), and investigate the removal efficiency of geosmin which taste and odor causing compounds in drinking water supplies through batch test. The results for the adsorption isotherm was analyzed by using the Langmuir equation and Freundlich equation, generally being applied. And the study showed that the both Langmuir and Freundlich equation explains the results better. Both of pseudo-first-order model and pseudo-second-order model were respectively applied for evaluation of kinetic sorption property of geosmin onto MPA. The adsorption experiment results using MPA showed that maximum adsorption capacity of MPA was lower 7 times than that of GAC, and adsorption rate of MPA was faster 11 times than that of GAC, on the basis of pseudo-first-order model. Therefore, it was determined that MPA was effectively able to remove geosmin in drinking water supplies in short EBCT condition, but regeneration cycle in MAP process was shorter than that in conventional process.

Three Dimensionally Ordered Microstructure of Polycrystalline TiO2 Ceramics with Micro/meso Porosity

  • Chang, Myung Chul
    • Journal of the Korean Ceramic Society
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    • v.53 no.2
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    • pp.227-233
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    • 2016
  • In order to make a highly ordered three-dimensional porous structure of titania ceramics, porogen beads of PS [Polystyrene] and PMMA [poly(methylmetacrylate)] were prepared by emulsion polymerization using styrene monomer and methyl methacrylate monomer, respectively. The uniform beads of PS or PMMA latex were closely packed by centrifugation as a porogen template for the infiltration of titanium butoxide solution. The mixed compound of PS or PMMA with titanium butoxide was dried and the dry compacts were calcined at $450^{\circ}C-750^{\circ}C$ according to the firing schedule to prepare micro- and meso- structures of polycrystalline titania with monodispersed porosity. Inorganic frameworks composed of $TiO_2$ were formed and showed a three Dimensionally Ordered Microstructure [3DOM] of $TiO_2$ ceramics. The pulverized particles of the $TiO_2$ ceramic skeleton were characterized using XRD analysis. A monodispersed crystalline micro-structure with micro/meso porosity was observed by FE-SEM with EDX analysis. The 3DOM $TiO_2$ skeleton showed opalescent color tuning according to the direction of light.

Incorporation of Graphitic Porous Carbon for Synthesis of Composite Carbon Aerogel with Enhanced Electrochemical Performance

  • Singh, Ashish;Kohli, D.K.;Singh, Rashmi;Bhartiya, Sushmita;Singh, M.K.;Karnal, A.K.
    • Journal of Electrochemical Science and Technology
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    • v.12 no.2
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    • pp.204-211
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    • 2021
  • We report, synthesis of high surface area composite carbon aerogel using additive based polymerization technique by incorporating graphitic porous carbon as additive. This additive was separately prepared using sol-gel polymerization of resorcinol-furfuraldehyde in iso-propyl alcohol medium at much above the routine gelation temperature to yield porous carbon (CA-IPA) having graphitic layered morphology. CA-IPA exhibited a unique combination of meso-pore dominated surface area (~ 700 m2/g) and good conductivity of ~ 300 S/m. The composite carbon aerogel (CCA) was synthesized by traditional aqueous medium based resorcinol-formaldehyde gelation with CA-IPA as additive. The presence of CA-IPA favored enhanced meso-porosity as well as contributed to improvement in bulk conductivity. Based on the surface area characteristics, CCA-8 composition having 8% additive was found to be optimum. It showed specific surface area of ~ 2056 m2/g, mesopore area of 827 m2/g and electrical conductivity of 180 S/m. The electrode formed with CCA-8 showed improved electrochemical behavior, with specific capacitance of 148 F/g & ESR < 1 Ω, making it a better choice as super capacitor for energy storage applications.

Three Dimensionally Ordered Microstructure of Polycrystalline Zirconia Ceramics with Micro-Porosity

  • Chang, Myung Chul
    • Journal of the Korean Ceramic Society
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    • v.53 no.1
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    • pp.50-55
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    • 2016
  • In order to make a highly ordered three-dimensionally macro-porous structure of zirconia ceramics, porogen precursors PMMA beads were prepared by emulsion polymerization using acrylic monomer. The monodisperse PMMA latex beads were closely packed by centrifugation as a porogen template for the infiltration of zirconium acetate solution. The mixed compound of PMMA and zirconium acetate was dried. According to the firing schedule, dry compacts of PMMA and zirconium acetate were calcined at $475^{\circ}C$ to obtain micro-, macro-, and meso- structures of polycrystalline zirconia with monodispersed porosity. Inorganic frameworks composed of $ZrO_2$ were formed and showed a three Dimensionally Ordered Microstructure [3DOM] of $ZrO_2$ ceramics. The obtained $ZrO_2$ skeleton was calcined at $710^{\circ}C$. The 3DOM $ZrO_2$ skeleton showed color tuning in solutions such as deionized [DI] $H_2O$ and/or methanol. The monodispersed crystalline micro-structure with micro/meso porosity was observed by FE-SEM.