Katakai, Akio*; Yotsumoto, Toshiro*; Takahashi, Akio*; Ueki, Yuji; Seko, Noriaki
JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 43, 2013/01
no abstracts in English
Mizote, Norihito*; Katakai, Akio; Tamada, Masao
Journal of Applied Polymer Science, 123(4), p.2172 - 2176, 2012/02
Surface of natural rubber was modified by radiation-induced grafting of 2-hydroxyethyl methacrylate (HEMA) to improve the properties of surface hardness, dry friction, wiping performance, and wear duration. The composition ration of HEMA to rubber was controlled from 0.29 to 0.93 by changing HEMA concentration and dose in graft polymerization. When this composition ration was higher than 0.7, the surface hardness was higher than 64 and the coefficient of dry friction lower than 0.65. Those values became better than those of commercially available chlorinated-rubber in terms of wear and friction against glass. The resulting wear resistance was 10 times higher than chlorinated rubber. However, the surface hardness in wet state was 62.5 since grafted-HEMA gave the hydrophilicity to the rubber. As a result, the grafted-HEMA rubber realized 95% and higher wiping performance of water on glass.
Mizote, Norihito*; Katakai, Akio*; Tamada, Masao
JAEA-Review 2010-065, JAEA Takasaki Annual Report 2009, P. 47, 2011/01
no abstracts in English
Mizote, Norihito*; Katakai, Akio; Tamada, Masao; Matsuoka, Hiroshige*
Journal of Applied Polymer Science, 117(5), p.2825 - 2830, 2010/09
Hydrophilic monomer, 2-hydroxyethyl methacrylate (HEMA), and hydrophobic monomer, 3-(methacryloyloxy)propyltris(trimethylsiloxy)silane (MPTS), were grafted on vulcanized rubber surface by simultaneous electron beam irradiation. We studied the characteristics of graft polymerization, the relationship between the contact angle of water on the modified surface and friction behavior at the moment of semi-dry. Grafted rubbers were investigated with composition ratio and contact angle. As a result of graft polymerization of HEMA and MPTS, the composition ratio increased as the monomer concentration and the irradiation dose increased. By the graft polymerization of HEMA, the contact angle decreased to approximately 70. By the graft polymerization of MPTS, the contact angle increased approximately to 108. Friction behavior at the moment of semi-dry was evaluated by which is difference with the coefficient of dry friction and maximum friction. The increase in the contact angle owing to hydrophobic properties by graft polymerization of MPTS led to the decrease of . The decrease in the contact angle owing to hydrophilic properties by graft polymerization of HEMA resulted in the increase of .
Go, Yasuhiro*; Yoshida, Hiromi*; Jo, Akinori*; Tamada, Masao; Katakai, Akio
Proceedings of 2008 Conference on Ion Exchange Technology (IEX 2008), p.353 - 361, 2008/07
Although granular anion exchange resins are useful for column-mode removal of nitrate in water, sizes of granular resins used in industrial scale columns are ca. 0.5 mm to reduce pressure loss in column operations. Since large granular resins bring down adsorption kinetics, it is difficult to supply water polluted with nitrate to granular resin packed columns at extremely high flow rates more than 1000 h in space velocity (SV). In this work, we have prepared an anion exchange fiber named FBDA, which rapidly takes up nitrate in column-mode even at the flow rate of feed of 3000 h in SV. FBDA was prepared by electron beam irradiation induced liquid phase graft polymerization of chloromethylstyrene (CMS) onto polyethylene-coated polypropylene fiber (PPPE; 1.5 denier) and the subsequent quaternization of the CMS-grafted fiber with n-butyldimethylamine (BDA). The resulting BDA-fixed fiber (FBDA) has anion exchange capacity of 2.2 meq/g. To the column (i.d. 1.3 cm) containing 2.0 mL wet FBDA, 1 mM nitrate feeding solutions in the absence and presence of a competing anion was fed to the column at given flow rates. In the absence of a competing anion, shapes of breakthrough profiles of nitrate are independent of the flow rates from 1000 to 3000 h in SV, giving the constant breakthrough capacity for nitrate as high as 1.1 mmol/g. Effect of chloride and sulfate was tested at the flow rate of 1000 h. In the presence of 1 mM and 5 mM chloride, breakthrough capacities for nitrate were reduced to 0.83 and 0.48 mmol/g, respectively. However, equimolar sulfate reduced the breakthrough capacity down to 0.43 mmol/g. Thus, the presented FBDA is useful for rapid purification of water contaminated with low concentration levels of nitrate, so long as concentrations of chloride and sulfate are nearly equal orders as those in most river waters. Almost the same results were also obtained in case of the triethylamine-fixed fiber named FTEA.
Awual, Md. R.*; Jo, Akinori*; Tamada, Masao; Katakai, Akio
Nihon Ion Kokan Gakkai-Shi, 18(4), p.422 - 427, 2007/10
Fibrous arsenate adsorbent was prepared by loading Zr(IV) onto a bifunctional cation exchange fiber containing both phosphonate and sulfonate. This bifuctional cation exchange fiber was prepared by phosphorylation and sulfonation of the precursory fiber, which was obtained by co-graft polymerization of chloromethylstyrene and styrene onto polyethylene coated polypropylene fiber. Performances of the Zr(IV) loaded fiber as arsenate adsorbent was studied in columnar mode. The column packed with Zr(IV) loaded fiber removed arsenate from a weakly acidic pH solution containing 0.016 mM arsenate (1.2 mg of As dm) even at a flow rate of 200 h in space velocity. Sodium salts of chloride, nitrate and sulfate did not interfere with uptake of arsenate but they slightly enhanced arsenate uptake. Adsorbed arsenate was quantitatively eluted with aqueous sodium hydroxide, and then the column was able to be regenerated by contact with dilute sulfuric acid for the next arsenate adsorption operation.
Jo, Akinori*; Shibata, Yoshikazu*; Tamada, Masao; Seko, Noriaki; Katakai, Akio
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 43, 2007/02
Adsorbent fiber of bifunctional chelating was synthesized by grafting of the precursor of aminomethylphosphpnate and sulfonate onto polyethylene fiber. Breakthrough curve showed the same characterisctics in the space velocity from 50 to 1000 h when 0.01 M Zn solution was pumped into the column of the synthesized fiber adsorbent. In thease cases, the adsorption capacities of Zn were 0.72-0.85 mmol/g-ad. The adsorped Zn could be eluted quantitaively by 1 M HCl solution.
Ueki, Yuji; Umemura, Tomonari*; Iwashita, Yoshikazu*; Hotta, Hiroki*; Odake, Tamao*; Tsunoda, Kinichi*; Katakai, Akio; Tamada, Masao
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 58, 2007/02
In late years, the studies on monolithic columns, which consist of porous material with through-pore of a few micrometer dimensions, have been vigorously performed for rapid and high-resolution separations. Monolithic capillary columns for reversed-phase liquid chromatography were directly prepared by ray-induced polymerization of hexyl methacrylate (HMA) and ethylene dimethacrylate in the fused silica capillaries, 0.25 mm in inner diameter. High separation efficiency of the monolithic columns were realized when the columns were prepared in the condition of 10 kGy irradaiation, total monomer concentration of 20% inclusive 25% crosslinker. The produced HMA-based monolithic columns were composed of adhered polymer particles, 1 m and less than in diameter. The pressure drop of column, this 200 mm long, was below 2.0 MPa at linear velocity of 1 mm s. The height equivalent to a theoretical plate was approximately 30 m for the five kinds of alkylbenzenes.
Katakai, Akio; Tamada, Masao; Nagamoto, Hiroyuki*; Ono, Sayuri*; Miyagawa, Hiroshi*
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 49, 2007/02
no abstracts in English
Wada, Yuki; Mitomo, Hiroshi*; Kasuya, Kenichi*; Nagasawa, Naotsugu; Seko, Noriaki; Katakai, Akio; Tamada, Masao
Journal of Applied Polymer Science, 101(6), p.3856 - 3861, 2006/09
Radiation-induced graft polymerization of acrylic acid (AAc) on the surface of poly(3-hydroxybutyric acid) (PHB) film was carried out by applying pre-irradiation techniques. The PHB films grafted with AAc (PHB-g-AAc) possessed a degree of grafting higher than 5% have completely lost the enzymatic degradability. The enzymatic degradability of the grafted film was recovered by remolding. And the highest enzymatic degradation rate was observed to grafted films with AAc 10% of degree. Difference of enzymatic degradability of PHB-g-AAc film was caused by decrement of amount of enzyme contact and decrement of crystallinity of PHB by remolding.
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.
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%.
Seko, Noriaki; Katakai, Akio; Tamada, Masao; Sugo, Takanobu*; Yoshii, Fumio
Separation Science and Technology, 39(16), p.3753 - 3767, 2004/00
Fibrous amidoxime adsorbents were prepared by radiation-induced co-grafting of acrylonitrile (AN) and methacrylic acid (MAA) and subsequent amidoximation. Adsorption of uranium in seawater was evaluated by pumping seawater into the adsorbent column. The best monomer ratio of AN and MAA was 7:3 for continual usage of uranium adsorption. Though hydrochloric acid is an effective eluting agent for the metals adsorbed on the adsorbent, amidoxime groups were simultaneously damaged after five cycles of adsorption-desorption. This deterioration was reduced by an alkaline treatment of the adsorbents after each elution. Furthermore, various organic acids were examined as elution agents. It was found that the 80% of adsorption activity was still maintained after five cycles of adsorption-desorption when tartaric acid was used for eluting agent.
Seko, Noriaki; Katakai, Akio; Hasegawa, Shin; Tamada, Masao; Kasai, Noboru; Takeda, Hayato*; Sugo, Takanobu; Saito, Kyoichi*
Nuclear Technology, 144(2), p.274 - 278, 2003/11
The total amount of uranium dissolved in seawater at a uniform concentration of 3 mg-U/m in the world's oceans is 4.5 billion tons. An adsorption method using polymeric adsorbents capable of specifically recovering uranium from seawater is reported to be economically feasible. A uranium-specific non-woven fabric was used as the adsorbent packed in an adsorption cage. We submerged adsorption cages, 16 m in cross-sectional area and 16 cm in height, in the Pacific Ocean at a depth of 20 m at 7 km offshore of Japan. The cage consisted of stacks of 52,000 sheets of the uranium-specific non-woven fabric with a total mass of 350 kg. The total amount of uranium recovered by the non-woven fabric was more than one kg in terms of yellow cake during a total submersion time of 240 days in the ocean.
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.
Katakai, Akio; Kasai, Noboru; Tamada, Masao; Hasegawa, Shin; Seko, Noriaki; Kawabata, Yukiya*; Onuma, Kenji*; Takeda, Hayato*; Sugo, Takanobu
JAERI-Tech 2002-040, 79 Pages, 2002/03
The present report dealt with experimental methods of adsorbents synthesis, recovery, elution, analysis in experimental equipment for recovery of rare metals from seawater to evaluate performance of the adsorbent synthesized by radiation-induced graft-polymerization. In the adsorbent synthesis, monomers of acrylonitrile and methacryl acid were continuously co-grafted into polymer nonwoven fabric irradiated with electron beam. The grafted nonwoven fabric was amidoximated and treated with alkaline solution in batch processing. The obtained adsorbent fabrics which were cut into 116 sheets of the square, 160 mm×290 mm, were alternatively stacked with spacers to make an adsorbent cassette. In recovery process, a large-sized cage packing 144 pieces of the adsorbent cassette was dipped into sea in the depth of 20 m by using an experimental marine equipment. In the case of a small-sized cage, there are 36 adsorbent cassettes in it. In elution step, first, marine animals which were adhered on the adsorbent cassette were washed out immediately after the adsorbent cassettes were recovered from sea. From every 72 adsorbent cassettes packed into elution unit, second, alkaline and rare metals were fractionally eluted by changing acid concentration in fractional elution equipment. The eluted metals were adsorbed onto a commercial chelate resin to transport them to purificatory factory. Concentrations of metals in eluent and waste solution were analyzed with inducticely coupled plasma atomic emission and mass spectrometry (ICP-AES and ICP-MS). The rare metal distribution in the adsorbent was evaluated by using the same analytical methods.
Tamada, Masao; Kasai, Noboru; Seko, Noriaki; Hasegawa, Shin; Kawabata, Yukiya*; Onuma, Kenji*; Takeda, Hayato*; Katakai, Akio; Sugo, Takanobu
JAERI-Tech 2001-065, 39 Pages, 2001/11
Positioning and monitoring system for marine component in recovery equipment of significant metals from seawater by using adsorbent was designed and assembled to avoid unexpected accidents. This system which was set on float part of the marine component obtains the position data by means of GPS satellites and send them to Takasaki and Mutsu establishments through satellite communication. As characteristic test for 20 days in the real sea, 256 data were obtained every 2 hours. The wrong data was eight and the positioning accuracy was 200.7m. To improve these characteristics, two new functions were added to the present firmware. These are to raise positioning resolutions in longitude and latitude from 0.001 to 0.00001 degree and to average remaining three data of positioning after maximum and minimum data were removed from continuous five times positioning. The improved system shows no wrong datum, average positioning of 6.74m. This performance is enough to prevent marine equipment from its drifting accident.
Takeda, Hayato*; Onuma, Kenji*; Tamada, Masao; Kasai, Noboru; Katakai, Akio; Hasegawa, Shin; Seko, Noriaki; Kawabata, Yukiya*; Sugo, Takanobu
JAERI-Tech 2001-062, 66 Pages, 2001/10
Real sea experiment for the recovery of significant metals such as uranium and vanadium has been carried out at the offing of Mutsu establishment to evaluate the adsorption performance of adsorbent synthesized by radiation-induced graft-polymerization. After elution of uranium and vanadium from the adsorbent, their metals were adsorbed onto the conventional chelate resin. This chelate resin in a plastic column was further put in a cylindrical stainless transport container. The container was transported to the facility for separation and purification by a truck for the exclusive loading. The maximum concentration is 60 Bq/g when the uranium is adsorbed on the chelate resin. Transportation of recovered metals can be treated as general substance since these amount and concentration are out of legal control. However, the recovered metals were transported in conformity to L type transportation as a voluntary regulation. The strength analysis of the container was equal to the safety level of IP-2 type which is higher transportation grade than L type .