RA carbon cryogels depended on the constituent ratio of precur-
sors and the pH of the RA solution, probably due to the variation
of the subsequent gel particle size. The carbon gels prepared in
this study were mesoporous materials with a modal diameter of
20 nm.
[TANSO 2008 (No. 231) 13–7.]
doi:10.1016/j.carbon.2008.01.015
Influence of pore structure and particle size on the rate
determining step of lead (II) ion and nitrobenzene adsorption by
activated carbons
Shinya Yamanaka
a
, Motoi Machida
a
, Masami Aikawa
b
,
Hideki Tatsumoto
a
a
Graduate School of Engineering, Chiba University, 1-33 Yayoicho,
Inage-ku, Chiba 263-8522, Japan
b
Faculty of Science, Kisarazu College of Technology,
2-11-1 Kiyomidai-higashi, Kisarazu, Chiba 292-0041, Japan
The influence of pore structure and particle size on the rate
determining step of lead (II) ion and nitrobenzene adsorption
onto activated carbons (ACs) having no surface oxygen has been
studied. The adsorption kinetics were examined using the Lang-
muir type rate equation. Nitrobenzene adsorption rate was found
to be always controlled by collision between adsorbate and
adsorption sites. Though the rate determining step of lead
adsorption might include exterior and inter-particle diffusion, it
could be shifted from exterior and inter-particle diffusion to col-
lision between adsorbate and adsorption sites with either
increasing mesopore content or reducing particle size by pulveri-
zation of the ACs.
[TANSO 2008 (No. 231) 18–20.]
doi:10.1016/j.carbon.2008.01.016
Estimation of pore structures in carbon fibers prepared from
polymer blends during carbonization by small-angle X-ray
scattering
Katsuya Fukuyama
a
, Yoshikiyo Hatakeyama
b
, Tatsuro Hoshino
b
,
Asao Oya
c
, Keiko Nishikawa
d
a
Center for Liberal Arts, Meiji Gakuin University,
1518 Kamikurata, Totsuka, Yokohama 244-8539, Japan
b
Graduate School of Science and Technology, Chiba University,
1-33 Yayoi, Inage, Chiba 263-8522, Japan
c
Graduate School of Engineering, Gunma University, 1-5-1 Tenjin,
Kiryu, Gunma 376-8515, Japan
d
Graduate School of Advanced Integration Science, Chiba University,
1-33 Yayoi, Inage, Chiba 263-8522, Japan
Following an investigation of the pore structure of carbon
fibers prepared from polymer blends consisting of carbon precur-
sor resin and pore forming resin by measurements of small-angle
X-ray scattering (SAXS), and the heat treatment temperature
(HTT) dependence of the pore structure, a least-square-fitting
analysis of theoretical scattering intensities for experimental
intensities was introduced in order to obtain results with higher
reliability. We also measured SAXS intensity of the polymer blend
fiber without heat treatment and carbonization to investigate the
structure of the pore forming resin in the fiber. The structural
changes of the pore forming resin and the formed pores with heat
treatment and carbonization are discussed.
[TANSO 2008 (No. 231) 21–9.]
doi:10.1016/j.carbon.2008.01.017
Report on the round-Robin test of revised XRD Gakushin-method
Norio Iwashita
National Institute of Advanced Industrial Science & Technology (AIST),
Research Institute of Instrumentation Frontier, 1-1-1 Umezono,
Tsukuba, Ibaraki 305-8568, Japan
The purpose of the round-Robin test is to establish the stan-
dard procedure for the X-ray diffraction (XRD) measurements of
lattice parameters and crystallite sizes of carbon materials
(revised Gakushin-method). Five carbon samples, glassy carbon
heat-treated at 2200 °C, a raw coke, high modulus type of pitch
based carbon fiber, isotropic graphite block and natural graphite
powder, were prepared for the test as the first step in 2002. Two
decades of participants (Japanese Universities, Institutes and
Companies) carried out the round-Robin test. The measurement
of lattice parameters showed a high accuracy, with a measure-
ment error within 0.0002 nm in the case of graphitized samples.
However, the crystallite size measurements showed a large scatter
in results. The coefficient of variation for the crystallite size mea-
surements is more than 10%. To improve the accuracy of the crys-
tallite size measurements, it is necessary to use a reliable silicon
powder as the standard and to establish a criterion for the suitable
profile for the diffraction peaks of the standard silicon. In 2004,
three samples using different kinds of silicon powder were pre-
pared for the second stage of the round-Robin test. As the conse-
quence of the second stage test, a sample with commercial silicon
powder for XRD measurements showed relatively small scatter in
the results. Permissible conditions for the profile of the silicon dif-
fraction peak were described in the procedure specification.
[TANSO 2008 (No. 231) 30–41.]
doi:10.1016/j.carbon.2008.01.018
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46 (2008) 721– 722