| JSR TECHNICAL REVIEW No.116 (March, 2009) |
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| Development of Aromatic Polymer Electrolyte Membrane
with High Conductivity and Durability for Fuel Cell
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| Kohei Goto, Igor Rozhanskii, Yoshitaka Yamakawa, Toshihiro Ohtsuki, Yuji Naito
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This report describes a design, preparation and evaluation data of a novel polymer electrolyte membrane,
which have been successfully developed for the use in fuel cell vehicles (FCV) . This membrane is
prepared from the aromatic block copolymer, consisting of alternating hydrophilic stiff sulfonic acid-bearing
segments and hydrophobic flexible polymeric sub-units. A bicontinuous microphase-separated morphology
of the membrane has been attested, contributing to its excellent water resistance with keeping high proton
conductivity. The JSR membrane exhibits actually the same chemical stability as a conventional poly (perfluorosulfonic
acid) one, while outperforming the latter in power output of the fuel cell, life time and temperature
range. In particular, a cold start of FCV has been first demonstrated at -20 ºC, using this material.
A manufacturing of the JSR membrane in the semi-industrial scale is established. This technology has been
officially approved for the extension through the public road examination. The Award of the Society of
Polymer Science, Japan (SPSJ) in 2006 was given for developing novel aromatic polymer electrolyte membrane
with high performance for the practical use.
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| Aggregation Behavior of New Cyclic Saturated Copolymers Synthesized via
Ring-opening Methathesis Polymerization
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| Yoichi Ogata, Motoki Okaniwa, Yutaka Makita
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Cyclic saturated copolymers were prepared from 8-methyl-8-methoxycarbonyltetracyclo[4.4.0.12,5.17,10]
dodec-3-ene(MMT) with polar ester group and dicyclopentadiene (DCP) without polar group. This procedure
consisted of ring-opening metathesis polymerization (ROMP) followed by hydrogenation. Monomer
reactivity of DCP was higher than that of MMT, the monomer reactivity ratio rDCP varied from 1.423 to 1.062
in a temperature range from 80 to 130ºC. These kinetic results indicated that the copolymer had distribution
of DCP composition in a macromolecule chain, which could provide the interesting aggregation behavior.
The aggregation behaviors of the hydrogenated copolymer and the homopolymer in various solvents
were also examined using dynamic light scattering (DLS) and static light scattering(SLS). DLS analysis indicated
that the fast mode in each polymer is attributed to the diffusive motion of each single polymer
chain, while the slow mode in the copolymer is caused by aggregated polymer. The aggregation degree of
the copolymer decreased with increasing hydrophobicity of solvent, decreasing polymer concentration, decreasing
molecular size of solvent and increasing temperature. Based on these findings, the mechanism of
aggregation behavior was clarified that the DCP-rich unit in a macromolecule might be acting as core to
give the aggregation in poor solvent.
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| Characteristics of a Structural Color of Hollow Particles
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| Takeshi Watanabe, Keisuke Tsukimawashi, Nobuhiro Matsuda
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Structural color was appeared, when the particles which size was smaller than the wavelength of visible
light were accumulated regularly. The color was changed by the particle size, the incidence of the
light, and the distance between of two particles changed on drying process. On these results, we considered
structural color was appeared by behavior of the light according to the Bragg's Law.
In the case of using hollow particles which the diameter was micron order (2200 nm) , structural color
was appeared when the incidence of the light was over 60 degrees, especially over 75 degrees. Less than
60 degrees, we could not observe structural color owing to roughness of particle surface. More than 60 degrees,
we could observe both structural color and gloss.
These phenomena were due to behavior of the light between core and shell of the hollow particles
(thin-layer interference) , not the distance between particles on drying process. Moreover, the structural
color of hollow particles which size was micron order did not need regular accumulative structure. And it
was not affected by roughness of the base materials.
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Double Patterning Materials for Sub-40 nm Application
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Tomohiro Kakizawa, Yusuke Anno, Masafumi Hori, Gouji Wakamatsu, Atsushi Nakamura, Koichi Fujiwara, Makoto Sugiura
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In this paper authors will cover the fundamentals of litho freeze litho etch (LFLE) . This novel double
patterning process requires a freeze step that is applied to the first immersion lithography step. This
freeze step cross-links the first photoresist, allowing subsequent lithography to take place with no intermixing.
It is critical that the freeze step ensures efficient cross-linking to precisely retain the profiles of the first
pattern. By doing so, authors have been able to demonstrated high performance and good reliability, both
which are necessary for sub-40 nm half-pitch design rules. Results indicate that this freeze process has met
many of the necessary criteria in terms of depth of focus, process latitude, critical dimension uniformity,
along with etch transfer needed for next generation lithography. Additionally, through the unique use of
LFLE and cross line patterning, authors will demonstrate that this process can enable lithographers to resolve
narrow contacts holes using 44 nm L/S patterns.
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