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Volume 70, Issue 9
Journal of the Society of Fiber Science and Technology
Displaying 51-56 of 56 articles from this issue
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Xuzhe Zhao, Xianxiang Liang, Shuqin Han, Toshiyuki Uryu, Takashi Yoshi ...2014 Volume 70 Issue 9 Pages 191-196
Published: September 12, 2014
Released on J-STAGE: September 12, 2014
JOURNAL FREE ACCESSBioethanol was produced from agricultural residues in Hokkaido Prefecture, Japan, by dilute alkali pretreatment, and then successive saccharification with cellulase and fermentation with recombinant yeast pYBGA1 that is a recombinant laboratory yeast expressing β-glucosidase. The agricultural residues, beet pulp, beet leaf, corn stover, and weed were pretreated with 2% NaOH aqueous solution for 1 h at 121℃ to remove lignin. The pretreated beet pulp (20 g/L), for example, was then saccharified for 24 h by Cellic CTec (10 wt% to beet pulp) as the cellulase at 50℃ to give glucose (11.8 g/L) at relatively good rates. After the temperature decreased to 30℃, the resulting glucose was continuously fermented for 36 h by addition of 1 × 108 cells/mL of pYBGA1 yeast to give 5.54 g/L of bioethanol in 60% and 92% theoretical yields of cellulose in beet pulp and glucose saccharified, respectively. Other agricultural residues also afforded bioethanol by the successive saccharification and fermentation. It was found that the appropriate cellulase for saccharification differed with the kind of agricultural residue; beet pulp was effectively saccharified by Cellic CTec, beet leaf and corn stover by Sucrose C, and weed by Sumizyme C. These agricultural residues were found to be suitable for the production of bioethanol because Hokkaido Prefecture is the most abundant producer of beets and corn in Japan, and accordingly, agricultural residues are easily available. pYBGA1 was also found to be a good yeast for the fermentation of sugars saccharified from agricultural residues.View full abstractDownload PDF (743K) -
Lei Du, Isao Tabata, Kazumasa Hirogaki2014 Volume 70 Issue 9 Pages 197-202
Published: September 12, 2014
Released on J-STAGE: September 12, 2014
JOURNAL FREE ACCESSIn this study, a new organic aerogel was prepared through a straightforward method. Para-aramid fiber used as the precursor was dissolved in the solution of dimethyl sulfoxide (DMSO) / tetrabutylammonium fluoride (TBAF), then regenerated in the acetone and dried by the supercritical CO2 to obtain the final aerogel. The aerogel was characterized by the density measurement, the SEM observation, and the BET method. The results show that the as-prepared aerogel, which was regenerated and dried in the optimal condition, has regular bundle of molecular chain with the width about 20 nm. In this structure, there are lots of nanopores with the average pore size of 11.535 nm that belongs to mesoporous, and with the peak of the pore size distribution of 0.77 nm that belongs to micropore. Besides, the nanopores are open-pores cross-linked each other forming the 3D-network. Meanwhile, the sample has large specific surface area of 510 g / m3 and density is as low as 0.083 g / cm3 (up to 94.3% of porosity).View full abstractDownload PDF (2311K) -
―Effect of the Composition of Sheath Layer with Constant High-Isotacticity Polypropylene Content―Youhei Kohri, Tomoaki Takebe, Yutaka Minami, Toshitaka Kanai, Wataru T ...2014 Volume 70 Issue 9 Pages 203-212
Published: September 12, 2014
Released on J-STAGE: September 12, 2014
JOURNAL FREE ACCESSDevelopment of metallocene catalyst provided the technologies for producing new types of polyethylene (PE) and polypropylene (PP). Based on this technology, PPs with controlled low-isotacticity (LPP) has been developed and applied for the production of elastomeric fibers. However, difficulty arose in the spun-bonding process of non-woven fabrics consisting of the LPP fibers because of its low crystallizability. With the aim of improving the processablity, melt spinning of sheath-core type bicomponent fibers was performed in this research using the blend of LPP and ordinary high-isotacticity polypropylene (IPP) as the sheath component and pure LPP as the core component. The prepared as-spun fibers with IPP content of 10 wt% in the sheath showed elastomeric property with reasonably good elastic recovery of higher than 85 wt%. The elastic recovery showed slight reduction with the increase of sheath layer composition from 0 to 50 wt%, which corresponds to the increase of total IPP content from 0 to 5 wt%. Tensile modulus and tensile strength of the as-spun bicomponent fibers increased significantly with the increase of total IPP content. Structural analyses of as-spun fibers consisting of LPP and IPP revealed that the crystallization of IPP component was enhanced especially when the composition of sheath component was low while that of LPP was suppressed significantly with the increase of the total IPP content. These results suggested the high modulus of sheath component in the fibers with low sheath layer composition.View full abstractDownload PDF (3156K) -
Masahiro Suzuki, Masahiro Kikuchi, Kenji Hanabusa2014 Volume 70 Issue 9 Pages 213-217
Published: September 12, 2014
Released on J-STAGE: September 12, 2014
JOURNAL FREE ACCESSTitanium oxide nano-networks, which have various crystal structures, were fabricated by the sol-gel polymerization in an organogel formed by L-isoleucine organogelator and their photocatalytic activities were evaluated by a methylene blue method. The TiO2 nano-networks were formed by which the self-assembled nanofibers of the gelator acted as a template, and their crystal structure was controlled by the calcination temperature. The rutile TiO2 nano-network, which was fabricated at 700℃, showed a good photocatalytic activity.View full abstractDownload PDF (867K) -
Qizheng Li, Feiyan Zhang, Xiaoke Jin, Shengcheng Zhang, Chengyan Zhu2014 Volume 70 Issue 9 Pages 218-224
Published: September 12, 2014
Released on J-STAGE: September 12, 2014
JOURNAL FREE ACCESSIn the textile industry, an innovative approach to achieving a special color is to use only a few colored yarns to gain various fabric color effects. This technology is highly environmentally friendly and can greatly reduce wastewater pollution caused by fabric dyes. In practice, however, matching the color of a woven fabric with the targeted or desired color by interweaving colored yarns experimentally has been difficult. Base on the optical color mixing theory and previous research on pre-colored fiber blending, this paper proposes a new model with an adjustable parameter M to predict the mixed color of yarn-dyed fabric made of dope-dyed polyester filaments. Experiments were carried out on 96 fabric samples that were a single color in the warp direction and different colors in the weft direction. A best-fit algorithm was used to determine that the optimum value of M for the Stearns-Noechel (S-N) color prediction model was 0.021. Differences in the values of the predicted and actual colors as determined with a spectrophotometer were calculated for three models: K/S, log (K/S), and S-N. The predictions of these models showed that the average color differences of the optimized S-N model were lower than those of the other two fixed-formula models. In addition, the optimized S-N model has different prediction accuracy in different range of wavelengths.View full abstractDownload PDF (2670K) -
Kentaro Tanaka, Koji Nishida, Barbara J. Gabrys, Margaret J. Lawrence, ...2014 Volume 70 Issue 9 Pages 225-231
Published: September 12, 2014
Released on J-STAGE: September 12, 2014
JOURNAL FREE ACCESSThe formation of aggregates of chitosan hydrochloride in aqueous solution, with and without added salt (i.e. NaCl), and the dissolution thereof have been studied using wide-dynamical range light transmittance measurements. The concentrations of chitosan and NaCl examined were 4 to 20 g/L and 0 to 2 mol/L, respectively. A large hysteresis loop was found for the formation of aggregates during cooling and the dissolution thereof during heating. In spite of the existence of the hysteresis, and regardless of the precise aggregation state and heating rate, the temperature at which the aggregates dissolved (namely the dissolution temperature) was uniquely determined for any given concentration of chitosan and NaCl. Further a critical dissolution ionic strength, below which no aggregation was detected, was established from the variation of dissolution temperature with ionic strength. The value of the Debye screening length, calculated at the critical dissolution ionic strength, corresponds fairly well to the size of the monomeric units comprising the chitosan chain. We therefore conclude that the aggregates of the chitosan are formed when electrostatic repulsive interactions between chitosan polyions are screened out allowing non-electrostatic attractive interactions to dominate.View full abstractDownload PDF (960K)