CARBON
4 7 ( 20 0 9 ) 1 2 0 7–12 0 8
available at www.sciencedirect.com
journal homepage: www.elsevier.com/locate/carbon
Tanso 235—Abstracts Control
carbon
dispersion in ethanol. The effect of C60 particle size on the yield
cryogel porous structures as electrodes for electric double-layer
and
behaviors
of
resorcinol-acetaldehyde
was found to be more significant than the stirring rate. Therefore,
capacitors
the SFM is more sensitive to the collision frequency between C60
Yusuke Kuwabara, Hironori Yano, Yoshiaki Kanematsu, Hirokazu
and amino-PEG compared to the diffusion of C60 in amino-PEG. In
Oda
order to understand the chemical modification mechanism, sim-
Faculty of Engineering, Kansai University, High Technology Research Center, 3-3-35 Yamate-cho, Suita 564-8680, Japan
ulation was performed based on a shrinking-core model assuming a chemical reaction as a rate limiting step. Using this model it was possible to estimate the number of amino-PEG molecules
The porous structures of mesoporous carbon materials, which
attached to C60. The results of simulation are a good fit to the
are known to be effective energy storage systems, were manipu-
gel permeation chromatography (GPC) data collected in the early
lated and their behaviors as electric double-layer capacitor elec-
period of the reaction considering that there is one amino-PEG
trodes were evaluated. Resorcinol (R) as the raw material and
attached to C60. As for the final period of reaction, the number
acetaldehyde (A) as the cross-linking agent were used to synthe-
of attached amino-PEG molecules increases according to the
size RA hydrogels via sol-gel polycondensation in a slightly basic
GPC data but the simulation shows an opposite tendency. This
aqueous solution. The RA hydrogels were freeze-dried and subse-
tendency was explained by a decrease in C60 surface activity
quently pyrolyzed at 1073 K for 30 min (heating rate, 10 K/min) to
and by additional reaction between products in the fluid phase.
obtain the RA carbon cryogels. The obtained samples were con-
[TANSO 2008;(235):268–74.]
firmed to have a high mesoporous carbon content, with a primary
doi:10.1016/j.carbon.2008.11.021
pore size diameter distribution of 20–40 nm. Due to a high ratio of ion adsorption and desorption capacitances, the samples were effective electrode materials capable of high-speed electrical charge and discharge for use as electrode materials of electric double layer capacitors. [TANSO 2008;(235):263–7] doi:10.1016/j.carbon.2008.11.020
Small-angle X-ray scattering study on structure of adsorbed molecular assemblies in carbon micropores Taku Iiyama, Sumio Ozeki Faculty of Science, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan The in situ small-angle X-ray scattering (SAXS) of water and
Solvent-free chemical modification of fullerene C60 by an
CCl4 adsorbed on pitch-based activated carbon fibers (ACF) was
amino-terminated polyethylene glycol
measured at 303 K. We extended the Debye–Bueche theory to
Manabu Okuyamaa, Akira Teramotob, Masaru Watanabeb,
the 3-phase mixed system (solid phase: carbon, adsorbed phase,
Hiroshi Inomatab
and vacant space) to obtain the average dimension of each phase
a
(ls, la, and lv). The la of water in a wider pore system (pore width:
Process Engineering Lab, Mitsubishi Chemical, Group Science and
Technology Research Center, Inc., 1000 Kamoshida-cho, Aoba-ku, Yokohama 227-8502, Japan b
Research Center of Supercritical Fluid Technology, Tohoku University,
6-6-11-414 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan The solvent-free chemical modification (SFM) of fullerene (C60) by polyethylene glycol with amino termination (amino-PEG) was
w = 1.13 nm) increases with the fractional filling /. On the other hand, la in a smaller pore system (w = 0.75 nm) does not change with /. These results show the difference in the cluster growing process with the pore width. It seems that the difference in the size and shape of water clusters in the adsorption and desorption processes should lead to adsorption hysteresis. The developed analysis method may give direct information on molecular
studied in order to improve fullerene dispersability. The effect
assemblies in micropores.
of the stirring rate and the C60 particle size on the modification
[TANSO 2008;(235):275–9.]
yield was investigated in the temperature range 60–120 °C for
doi:10.1016/j.carbon.2008.11.022
3–24 h. As a result, 65% of C60 was modified at 60°C for 24 h for
doi:10.1016/S0008-6223(08)00623-4