간행물

Carbon Letters KCI 등재 Carbon letters

권호리스트/논문검색
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권호

Vol.5 No.2 (2004년 6월) 6

1.
2004.06 구독 인증기관 무료, 개인회원 유료
Isotropic pitch-based carbon fiber was isothermally activated in CO2 atmosphere. Structural parameters of the isotropic carbon fibers and activated carbon fibers (ACFs) were evaluated by X-ray diffraction (XRD). The d002 and La of the carbon fibers were measured to be 4.04 a and 23.6 a and those of ACFs were 4.29 a and 22.7 a, respectively, representing less ordered through activation process. The pores in the ACFs were characterized by BET, and they showed super-high specific surface area of maximum value 3,495 m2/g from average pore size of 8.3 a at 59% burn-off. It was recognized that 8-9 a was optimum range of pore size for efficient creation of high specific surface area. The average size of the pores formed at higher temperature (1100℃) was larger than that of the pores formed at lower temperature (900℃).
3,000원
2.
2004.06 구독 인증기관 무료, 개인회원 유료
Adsorption isotherms of p-nitrophenol from its aqueous solutions on two samples of activated carbon fibres and two samples of granulated activated carbons have been determined in the concentration range 40~800 mg/L (ppm). The surface of these carbons was modified by oxidation with nitric acid and oxygen gas, and by degassing the carbon surface under vacuum at temperatures of 400℃, 650℃ and 950℃. The oxidation of carbon enhances the amount of carbon-oxygen surface groups, while degassing decreases the amount of these surface groups. The adsorption of p-nitrophenol does not depend upon the surface area alone but appears to be influenced by the presence of oxygen groups on the carbon surface. The adsorption decreases on oxidation while the degassing of the carbon surface enhances the adsorption. The decrease in adsorption depends upon the strength of the oxidative treatment being much larger in case of the oxidation with nitric acid, while the decrease in adsorption on degassing depends upon the temperature of degassing. The results show that while the presence of acidic surface groups which are evolved as CO2 on degassing suppress the adsorption of p-nitrophenol, the presence of non acidic surface groups which are evolved as CO on degassing tend to enhance the adsorption. Suitable mechanisms compatible with the results have been presented.
4,000원
3.
2004.06 구독 인증기관 무료, 개인회원 유료
Performance of carbon-carbon composites is known to be influenced by the fibre matrix interactions. The present investigation was undertaken to ascertain the development of microstructure in such composites when carbon fibres possessing different surface energies (T-300, HM-35, P120 and Dialed 1370) and pitch matrices with different characteristics (Coal tar pitch SP110℃ and mesophase pitch SP285℃) are used as precursor materials. These composites were subjected to two different heat treatment temperatures of 1000℃ and 2600℃. Quite interesting changes in the crystalline parameters as well as the matrix microstructure are observed and attempt has been made to correlate these observations with the fibre matrix interactions.
4,000원
4.
2004.06 구독 인증기관 무료, 개인회원 유료
The polymer with contents of C60 up to 57 wt.% was produced by mutual condensation of fullerene C60 and ethylenediamine. The investigations of this polymer as well as pristine fullerene to comparison were carried out by FT-IR and UV-Vis spectroscopy, ToF-SIMS, TGA, and elemental analysis. At least three kinds of components was revealed as building blocks of polymer. The fullerene cage underwent only distortion but didn't destroy during formation of polymer. The pure fullerene was found as an intermediate of the thermal decomposition of polymer. The conclusion that this polymer could serve as precursor to produce carbon nanomaterial with high concentration curved graphene sheets and can be used for gas adsorption and electrochemical application was made.
4,000원
5.
2004.06 구독 인증기관 무료, 개인회원 유료
The studies on activated carbon prepared from walnut shell and groundnut shell were undertaken to ascertain the effect of initial state of precursor and activation process on the development of porosity in the resulting activated carbon. Walnut shell based carbon shows the presence of cellular pores while Groundnut shell based carbon shows fibrillar pore structure. The adsorption parameters, characterization of product and scanning electron microscopic studies carried out showed the presence of mainly Micro, Meso and Macro porosity in carbon prepared from Walnut shell while mainly micro porosity was observed in Groundnut shell based activated carbon. An interrelationship between the adsorption efficiency and porosity in terms of quality control parameters, for before and after activation, was validated through the scanning electron microscopic data.
4,000원
6.
2004.06 구독 인증기관 무료, 개인회원 유료
The effect of compositions of Al2O3 in the mixed Fe/Al2O3 catalysts on the synthetic behaviors of carbon nanotubes (CNTs) by catalytic chemical vapor deposition (CCVD) process was investigated in wide range of the mixture ratios of support materials. CNTs were synthesized with Fe/Al2O3 catalysis under the condition of 40 min in synthetic time, and 923 K of synthetic temperature using C2H4 and H2 as synthetic and carrier gas, respectively. The carbon yield with the content of Al2O3 showed in a parabolic curve and the maximum carbon yield was 40 wt.% of Al2O3. As the mixture ratio of Al2O3 increased, decreasing tendency was observed in the diameter of CNTs. Specific surface areas of CNTs were increased with the increase of the mixture ratio of Al2O3.
4,000원