• 제목/요약/키워드: Carbonaceous materials

검색결과 91건 처리시간 0.026초

Purification of Multi Walled Carbon Nanotubes (Mwcnts) Synthesized by Arc Discharge Set Up

  • Malathi, Y.;Padya, Balaji;Prabhakar, K.V.P.;Jain, P.K.
    • Carbon letters
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    • 제11권3호
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    • pp.184-191
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    • 2010
  • Carbon nanotubes are unique tubular structures of nanometer diameter and large length/diameter ratio. The nanotubes may consist of one up to tens and hundreds of concentric shells of carbons with adjacent shells separation of ~0.34 nm. Multiwalled carbon nanotubes were synthesized by arc-discharge technique. MWCNTs were formed at the cathode deposit along with other carbonaceous materials like amorphous carbon, graphite etc. However, to get the best advantage of carbon nanotubes in various advanced applications, these undesired carbonaceous materials to be removed which is a challenging task. In the present study, various techniques were tried out for purifying MWCNTs such as physical filtration, chemical treatment and thermal annealing. SEM, FTIR, TGA and BET techniques were used to characterize the CNTs at various stages. Results shows that suitable chemical treatment followed by thermal annealing under controlled flow of oxygen gives the better route for purification of carbon nanotubes.

Novel Flexible Supercapacitors Fabricated by Simple Integration of Electrodes, Binders, and Electrolytes into Glass Fibre Separators

  • Yoo, Joung Eun;Bae, Joonho
    • 전기화학회지
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    • 제17권4호
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    • pp.237-244
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    • 2014
  • We report novel and simple structure of supercapacitors fabricated by using flexible glass fibre separators as templates. This method does not require separate electrodes, binders and high pressure/temperature to build the supercapacitor unit cells as required by the conventional technology. The supercapacitors were fabricated by drop-casting solution mixtures of carbonaceous active materials/gel electrolytes onto two sides of glass fibre separators. Two carbonaceous materials (nanoscaled activated carbons, multi-walled carbon nanotubes) were investigated as electrode materials. The electrochemical measurements reveal that the separatorbased supercapacitors using ACs successfully demonstrated significant mass specific capacitance ($22.3F\;g^{-1}$) and energy density ($9.7Wh\;kg^{-1}$), indicating this method can be useful in fabricating flexible, wearable and stretchable energy storage devices in more straightforward and cost-effective way than current technology.

임진강변 퇴적층 내 탄소물질들의 분포 및 특성 연구 (A Study on the Distribution and Property of Carbonaceous Materials in the Subsurface Sediments near the Imjin River)

  • 정상조
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제15권3호
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    • pp.34-43
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    • 2010
  • The fate of hydrophobic organic contaminants (HOCs) in ground water is highly affected by the distribution and property of the carbonaceous materials (CMs) in subsurface sediments. CMs in soils consist of organic matters (e.g., cellulose, fulvic acid, humic acid, humin, etc.) and black carbon such as char, soot, etc. The distribution and property of CMs are governed by source materials and geological evolution (e.g., diagenesis, catagenesis, etc.) of them. In this study, the distribution and property of CMs in subsurface sediments near the Imjin river in the Republic of Korea and HOC sorption property to the subsurface sediments were investigated. The organic carbon contents of sand and clay/silt layers were about 0.35% and 1.37%, respectively. The carbon contents of condensed form of CMs were about 0.13% and 0.45%, respectively. The existence of black carbon was observed using scanning electron microscopes with energy dispersive spectroscopy. The specific surface areas (SSA) of CMs in heavy fraction(HFrCM) measured with N2 were $35-46m^2/g$. However, SSAs of those HFrCM mineral fraction was only $1.6-4.3m^2/g$. The results of thermogravimetric analysis show that the mass loss of HFrCM was significant at $50-200^{\circ}C$ and $350-600^{\circ}C$ due to the degradation of soft form and condensed form of CMs, respectively. The trichloroethylene (TCE) sorption capacities of sand and clay/silt layers were similar to each other, and these values were also similar to oxidzed layer of glacially deposited subsurface sediments of the Chanute Air Force Base (AFB) in Rantoul, Illinois. However, these were 7-8 times lower than TCE sorption capacity of reduced layer of the Chanute AFB sediments. For accurate prediction of the fate of hydrophobic organic contaminants in subsurface sediments, continuous studies on the development of characterization methods for CMs are required.

고농도(高濃度) 유기물(有機物) 및 질소(窒素)를 함유(含有)한 산업폐수처리(産業廢水處理) 시스템 개발(開發) (Development of a System to Treat Industrial Wastewater with High Carbonaceous and Nitrogenous Materials)

  • 이용운;이병희;정선용;정수정
    • 상하수도학회지
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    • 제12권2호
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    • pp.67-75
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    • 1998
  • The purpose of this study is to develop a system for treating industrial wastewater with high carbonaceous and nitrogenous materials. To investigate the potential of using this system, a number of experiments are conducted for about 7 months with the varieties of COD and $NH_3-N$ concentrations, and hydraulic retention time. In the system, 1,500mg/L of COD is remover over 95% in a retention time as low as 9 hours, and the $NH_3-N$ removal efficience is nearly 100% with 90mg/L of $NH_3-N$ in the influent. These results illustrate that the system can effectively be used to treat industrial wastewater containing high concentration of COD and $NH_3-N$.

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Morphologies and surface properties of cellulose-based activated carbon nanoplates

  • Lee, Seulbee;Lee, Min Eui;Song, Min Yeong;Cho, Se Youn;Yun, Young Soo;Jin, Hyoung-Joon
    • Carbon letters
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    • 제20권
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    • pp.32-38
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    • 2016
  • In this study, cellulose nanoplates (CNPs) were fabricated using cellulose nanocrystals obtained from commercial microcrystalline cellulose (MCC). Their pyrolysis behavior and the characteristics of the product carbonaceous materials were investigated. CNPs showed a relatively high char yield when compared with MCC due to sulfate functional groups introduced during the manufacturing process. In addition, pyrolyzed CNPs (CCNPs) showed more effective chemical activation behavior compared with MCC-induced carbonaceous materials. The activated CCNPs exhibited a microporous carbon structure with a high surface area of 1310.6 m2/g and numerous oxygen heteroatoms. The results of this study show the effects of morphology and the surface properties of cellulose-based nanomaterials on pyrolysis and the activation process.

화염감지기에 대한 고찰

  • 이복영
    • 방재기술
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    • 통권13호
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    • pp.18-26
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    • 1992
  • This report is explained about operating principles, characteristices of flame detectors. Flame detector is designed to detect the UV (Ultraviolet) and IR (Infrared) rediation produced by flaming involving carbonaceous materials.

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