Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Saito, Kyoichi*; Asai, Shiho
Bunseki Kagaku, 66(11), p.771 - 782, 2017/11
Times Cited Count:1 Percentile:3.39(Chemistry, Analytical)Recovery and purification of rare metals, which are essential ingredients for highly functional materials, generally comes with operational difficulty. In this study, we have developed polymer adsorbents specially designed for highly-efficient adsorption of rare metal ions and exhibited their practical adsorption performances. Radiation-induced graft polymerization, one of the effective modification techniques for polymers, was employed for preparing the proposed adsorbents. Among such adsorbents, a 6-nylon fiber with nucleic-acid base, adenine, on the surface of the fiber demonstrated specific adsorption of ruthenium and palladium ions. In addition, a 6-nylon fiber with an extractant HDEHP (bis (2-ethylhexyl) phophoric acid) that has high affinity for lanthanides, achieved higher separation speed than a commercially available HDEHP-impregnated resin.
Saito, Kyoichi*; Kojima, Takashi*; Asai, Shiho
Bunseki Kagaku, 66(4), p.233 - 242, 2017/04
Times Cited Count:1 Percentile:3.39(Chemistry, Analytical)Insoluble cobalt ferrocyanide and sodium titanate specifically capture cesium and strontium ions, respectively, in water contaminated with radionuclides which is found in Fukushima Daiichi NPP. The inorganic compounds used in this study were formed as precipitates in the polymer chain grafted onto a commercially available 6-nylon fiber using radiation-induced graft polymerization. An impregnation structure with the precipitates entangled by the grafted polymer chain through an electrostatic interaction via multipoints was indicated. The resultant insoluble cobalt ferrocyanide- or sodium titanate-impregnated fiber exhibited a higher adsorption rate and adsorption capacity per gram of the inorganic compound for cesium or strontium ions in seawater than conventional granular adsorbents.
Saito, Toru; Okubo, Toshikazu*; Izumi, Keisuke*; Okawa, Yoshinao*; Kobayashi, Norihiro*; Yamazaki, Toru; Kawano, Katsumi; Isono, Takaaki
Teion Kogaku, 50(8), p.400 - 408, 2015/08
Aramid fiber-reinforced plastic (AFRP) has been developed as a structural material that has the advantages of light weight and high strength. In this study, tensile tests were carried out to measure the tensile properties of AFRP rod on the market for reinforcement of concrete at room temperature, 77 K and 4.2 K. Especially at cryogenic temperatures, it is difficult to perform a tensile test of the bar because the specimen slips through the jig grip. To prevent the rod from slipping, tensile tests were carried out with some filling conditions. The applicable and appropriate tensile test conditions were established by modifying the jig grip, treating the surface of the rod and using cryogenic epoxy infill to grip the rod. They were more than 1100 MPa. Additionally, the AFRP rod included a temperature dependence in which the Young's modulus increased as the test temperature decreased. It was confirmed that the Young's modulus increased because aramid fiber was more dominant than epoxy.
Katakai, Akio; Tamada, Masao; Nagamoto, Hiroyuki*; Miyagawa, Hiroshi*
Nihon Ion Kokan Gakkai-Shi, 16(2), p.122 - 126, 2005/05
A chelating fiber containing an amidoxime group as a chelate-forming group was prepared by radiation-induced cograft polymerization of acrylonitrile and methacrylic acid and subsequent conversion of the produced cyano group into the amidoxime group. The effect of repeated use of monomers for radiation-induced graft copolymerization on the composition of the graft chain and its adsorption capacity for metal ions was determined. The degree of cografting decreased by as low as 10% at the fourth cycle of cografting, compared with an initial degree of cografting of 170%, because the amount of homopolymer formed in cografting was negligibly small at 0.15 g/L of the monomer solution. The repeated use of monomers did not affect the amidoxime group density and the adsorption capacities of zinc and cadmium ions, resulting in the cost reduction of the preparation of the chelating fiber.
Igawa, Naoki; Taguchi, Tomitsugu; Nozawa, Takashi*; Snead, L. L.*; Hinoki, Tatsuya*; McLaughlin, J. C.*; Kato, Yutai*; Jitsukawa, Shiro; Koyama, Akira*
Journal of Physics and Chemistry of Solids, 66(2-4), p.551 - 554, 2005/02
Times Cited Count:48 Percentile:82.42(Chemistry, Multidisciplinary)Silicon carbide is an important engineering ceramic because of its high strength and stability at high temperature and low induced radioactivity after neutron irradiation. Though monolithic SiC is brittle and low toughness, SiC fiber reinforced SiC matrix composites significantly improve these properties and therefore are attractive candidate materials for fusion reactor structural applications. Recently, stoichiometric SiC fibers with superior mechanical properties have been produced. We carried out the optimization of interface and composite fabrication using the chemical vapor infiltration, which is the one of the best techniques to fabricate the SiC composite. The composite with higher density and homogeneous matrix was obtained by the optimization of materials and carrier gas flow rate. The porosity was decreased with increasing the fiber volume fraction. We adopted the carbon or carbon/SiC interface between fiber and matrix and we found that the dependence of interface thickness on the tensile properties was small in the interface thickness from 50 to 300 nm.
Seko, Noriaki; Kasai, Noboru; Tamada, Masao; Hasegawa, Shin; Katakai, Akio; Sugo, Takanobu*
JAERI-Tech 2004-076, 78 Pages, 2005/01
In September 1999, we have soaked 200 kg of fibrous amidoxime adsorbents, synthesized by radiation-induced graft polymerization, into seawater to evaluate their performance. Fractional elution facility was set effectively to elute the rare metals on adsorbents in Mutsu-Establishment. This facility consists of two parts of pre-washing and elution. The present report dealt with planning, manufacture and setting of fractional facility. Marine organism and slime on adsorbent cassette (290290160 mm) were washed out and every 72 cassettes were set in elution unit (12101210H1460 mm) with nonwoven materials as a packing to avoid elution loss. In the elution process alkaline and alkaline earth metals were eluted with low concentration hydrochloric acid (0.01M) and rare metals were eluted with high concentration (0.5M) after the packing of elution unit into fractional elution facility.
Seko, Noriaki; Takeda, Hayato*; Kasai, Noboru; Tamada, Masao; Hasegawa, Shin; Katakai, Akio; Sugo, Takanobu*
JAERI-Tech 2004-075, 51 Pages, 2005/01
Fibrous adsorbent which is synthesized by radiation induced graft polymerization on the trunk polymers such as polymer nonwoven fabrics and woven cloths exhibits an excellent selective adsorption against heavy metal ions and toxic gases at extremely low concentrations. Two equipments were installed to synthesize the metal-ion and gas adsorbents by means of the radiation-induced graft polymerization in the liquid phase and the dipping, respectively. In the reaction chamber of the liquid phase reactor, the oxygen decreased to 100ppm. The inside temperature raised to 80C. These characteristics satisfied the specification. The fabric transport can regulate the rate in the range from 1 to 10m/min. The reactor for the dip grafting could reduce the inside oxygen to 100ppm and inside temperature could reach to 80 C. The grafting of GMA was carried out as a characteristic test. The degree of grafting was controlled in the range from 40 to 70%.
Jo, Akinori*; Okada, Kenji*; Tamada, Masao; Kume, Tamikazu; Sugo, Takanobu; Tazaki, Masato*
Chemistry for the Protection of the Environment 4; Environmental Science Research, Vol. 59, p.49 - 62, 2005/00
Bifunctional cation exchange fibers were synthesized by co-grafting of chloromethylstylene and styrene. on polyethylene-coated polypropylene fibers. The grafted fibers were fictionalized by Arbuzov reaction, suffonation, and acid hydrolysis. Batchwise evaluation of metal ion selectivity clarified that the bifunctional fiber exhibited cooperative recognition of metal ions by both functional groups. The bifunctional fiber took up Pb(II) more rapidly than the monofunctional phosphoric acid fiber and commercial resin adsorbent. Column-mode experiment revealed that flow rate was independent of break through profiles of Pb(II) up to flow rate of 900 h in space velocity.
Yoshikawa, Masahito; Sugimoto, Masaki
Kombatekku, 32(8), p.56 - 60, 2004/08
no abstracts in English
Tamada, Masao
Kankyo Shigen Kogaku, 51(2), p.99 - 101, 2004/04
Fibrous chelate adsorbents have been synthesized by radiation-induced graft polymerization onto polyethylene nonwoven fabric. Graft polymerization was induced by electron beam irradiation to the trunk polymer. Then, irradiated trunk polymer was contacted with reactive monomer having function of chelate agent or its precursor. The precursor was chemically converted to chelate agent. The resulting fibrous chelate adsorbent gave the high space velocity more than 500 h in removal of lead from its solution. Such adsorbent was applied to the removal of cadmium from scallop processing waste and the removal of lead from the contaminated water which was produced by washing the inside of incinerator.
Ishihara, Masahiro; Hanawa, Satoshi; Sogabe, Toshiaki; Tachibana, Yukio; Iyoku, Tatsuo
Materials Science Research International, 10(1), p.65 - 70, 2004/04
no abstracts in English
Jo, Akinori*; Kugara, J.*; Trobradovic, H.*; Yamabe, Kazunori*; Sugo, Takanobu; Tamada, Masao; Kume, Tamikazu
Industrial & Engineering Chemistry Research, 43(7), p.1599 - 1607, 2004/03
Times Cited Count:28 Percentile:67.22(Engineering, Chemical)Fibrous iminodiacetic acid cheating cation exchangers were derived from chloromethylstyrene radiation-grafted polyethylene-coated polypropylene filamentary fiber and its nonwoven cloth. Ligand contents and acid capacities of the resulting cation exchangers were ca. 2 mmol/g and ca. 4 mmol/g for the filamentary fiber and for the non-woven cloth, respectively. The selectivity sequence of nonwoven cloth shape for dialect metal ions is Mg(II) Ca(II) Co(II) Zn(II) Cd(II) Ni(II) Pb(II) Cu(II). Capacities in mmol/g at pH 5 were Ca(II) 0.91, Mg(II) 0.98, Cd(II) 1.5, Ni(II) 1.5, Pb(II) 1.6, Cu(II) 1.8. Column mode for filamentary fiber shape revealed that breakthrough capacities for Cu(II) (ca. 1 mmol/g) were not dependent on flow rates up to 200 300 h in space velocity.
The, D. T.; Yoshii, Fumio; Nagasawa, Naotsugu; Kume, Tamikazu
Journal of Applied Polymer Science, 91(4), p.2122 - 2127, 2004/02
Times Cited Count:15 Percentile:45.21(Polymer Science)no abstracts in English
Ishihara, Masahiro
Tanso, (208), p.135 - 144, 2003/09
no abstracts in English
Kugara, J.*; Trobradovic, H.*; Jo, Akinori*; Sugo, Takanobu; Tamada, Masao; Katakai, Akio
Nihon Ion Kokan Gakkai-Shi, 14(Suppl.), p.77 - 80, 2003/00
Chloromethylstyrene-grafted polyethylene-coated polypropylene fiber (0.9 denier) was functionalized by reaction with diethyl iminodiacetate and hydrolysis of the ester introduced. An acid capacity of the resulting chelating fiber (FIDA-f) was 4.3 meq/g. Although a maximum permissible flow rate of feeds was depressed with an increase in the conditioning pH of the FIDA-f column, breakthrough profiles of Pb(II) were independent of the flow rate of feeds up to 800/h in space velocity (SV). The usefulness of FIDA-f was demonstrated by quantitative removal of Pb(II) from 600 bed volumes of a Pb(II)-spiked river water (5 ppm) at a flow rate of SV 400/h.
Jo, Akinori*; Okada, Kenji*; Nakao, Mitsuhiro*; Sugo, Takanobu; Tamada, Masao; Katakai, Akio
Nihon Ion Kokan Gakkai-Shi, 14(Suppl.), p.69 - 72, 2003/00
The titled bifunctional fiber (FVCPS-f) were prepared by treating chloromethylated vinylbiphenyl-grafted polyethylene-coated polypropylene fiber (0.9 denier, length 3.8 cm) with triethyl phosphite, chlorosulfonic acid, and conc. hydrochloric acid, in successive. Phosphorus and sulfur contents of FVCPS-f were 1.8 and 0.7 mmol/g, respectively (acid capacity 4.2 meq/g). Its breakthrough capacity (BC) for Fe(III) gradually decreased with an increase in flow rate of feeds from 20/h to 1000/h in space velocity (SV); for instance, its BC at a SV 1000/h was 0.12 mmol/g, whereas both a commercially available phosphonate resin and a monofunctional phosphonate fiber were not able to give practically meaningful BC at such an extremely high flow rate.
Ishiyama, Shintaro; Muto, Yasushi
Nihon Kinzoku Gakkai-Shi, 66(6), p.662 - 669, 2002/06
no abstracts in English
Yamada, Reiji; Igawa, Naoki; Taguchi, Tomitsugu
Advanced SiC/SiC Ceramic Composites: Developments and Applications in Energy Systems; Ceramic Transactions Vol. 144, p.289 - 299, 2002/00
A Finite-element method(FEM) was applied for a computer simulation of a laser flash method for measuring thermal diffusivity of SiC/SiC composites. To understand the effect of individual fiber and matrix thermal conductivities as well as fiber volume on the overall composite's thermal diffusivity, the cases of high and low values for the fiber and matrix thermal conductivities were calculated as a function of fiber volume fraction at specimen temperatures of 200 and 900. The results of calculations showed that if low thermal conductive SiC fibers were used, the increase of fiber volume worsened the composite thermal diffusivity with highly conductive matrix, whereas when using highly conductive SiC fiber, the effect of increasing fiber volume was positive for increasing the composite diffusivity with low matrix thermal conductivity. The specimen temperatures altered the values of the composite thermal diffusivity but the qualitative tendencies above mentioned were maintained.
Ishitsuka, Etsuo; Uchida, Munenori*; Sato, Kazuyoshi; Akiba, Masato; Kawamura, Hiroshi
Fusion Engineering and Design, 56-57, p.421 - 425, 2001/10
Times Cited Count:2 Percentile:19.6(Nuclear Science & Technology)no abstracts in English
Sugo, Takanobu; Tamada, Masao; Seguchi, Tadao; Shimizu, Takao*; Uotani, Masaki*; Kashima, Ryoichi*
Nihon Genshiryoku Gakkai-Shi, 43(10), p.1010 - 1016, 2001/10
Times Cited Count:16 Percentile:73.13(Nuclear Science & Technology)The cost of uranium recovered from seawater was estimated by using the amidoxime adsorbent of polymer fibers synthesized by radiation modification, and the technical problems in the recovery system were extracted. The cost of adsorbent materials, storage in seawater for uranium absorption, and the uranium detachment from the adsorbent was estimated respectively in three different systems of the storage in seawater as a buoy, floating body, and chain binding system. The recovery cost of uranium from seawater was estimated to be 810 times of that from mine uranium. More than 80% of the total cost was occupied by the cost for storage in seawater, which is owing to a weight of metal cage for the holding of adsorbents. The cost can be attained to half by the reduction of the weight to 1/4. One of facing research subject is the improvement of adsorbent ability, since the cost directly depends on the adsorbent performance.