Electron-beam-induced chromism combined with photo- or thermal reverse reaction for color imaging

Enomoto, Kazuyuki; Maekawa, Yasunari; Kono, Sachiko*; Iwasaki, Masakazu*; Narita, Tadashi*

Journal of Photopolymer Science and Technology, 23(2), p.217 - 224, 2010/06

https://doi.org/10.2494/photopolymer.23.217

Reversible color imaging on polymer films with spiropyran (SP-NO) or diarylethene (DE) has been examined by electron-beam (EB) induced chromism combined with a photo- or thermal reverse reaction. Colorless SP-NO in a film transformed into red-colored merocyanine (MC-NO), which subsequently converted to the original SP-NO via thermal treatment. In contrast, a photo reverse reaction could be applied for EB-induced color imaging using DE in the polymer films, where the thermally stable colored close-form can be converted to the original colorless open-form via photoreaction. The color images of 200 nm L/S patterns were produced in the PMMA film containing SP-NO; the images could be faded upon the thermal treatment. It is noted that these reactions are the first example for reversible transformation of color imaging induced by EB radiation together with heat or light treatment.

Oxidation process of xylene in air using Ag/TiO under electron beam irradiation

Hakoda, Teruyuki; Matsumoto, Kanae; Mizuno, Akira*; Narita, Tadashi*; Kojima, Takuji; Hirota, Koichi

IEEE Transactions on Industry Applications, 44(6), p.1950 - 1956, 2008/11

https://doi.org/10.1109/TIA.2008.2006328

Oxidation of xylene and its irradiation-induced organic byproducts in air using Ag-loaded TiO (Ag/TiO) beds was studied under electron beam (EB) irradiation. The Ag/TiO beds were placed in an irradiation or a non-irradiation space in order to identify the oxidation of xylene/its byproducts by EB irradiation, by catalytic process, and by a combination of the two. Placement of the Ag/TiO bed to the irradiation space resulted in the suppression of xylene decomposition. On the other hand, production of CO was observed in the gas phase of the irradiation space and on the surface of the Ag/TiO pellets placed both in the irradiation and non-irradiation spaces. The concentration of CO became higher when the layer was placed in the non-irradiation space. The production of CO was enhanced by loading of Ag to the TiO pellet surface. The highest concentration of CO was obtained for Ag/TiO with Ag contents greater than 5wt%.

-rays radiation-induced homopolymerization of trifluorovinyl heptafluoropropyl ether

Narita, Tadashi*; Enomoto, Kazuyuki*; Maekawa, Yasunari; Yoshida, Masaru; Ichikawa, Mitsuru*; Hamana, Hiroshi*

Journal of Fluorine Chemistry, 128(1), p.52 - 54, 2007/01

https://doi.org/10.1016/j.jfluchem.2006.08.009

Perfluorinated polymers have expected to be the key materials for fuel cell membranes owing to the high chemical stability, thermo-durability and optical property. However, a homopolymer of FVPE has never yielded under usual polymerization conditions and alternating copolymers with several non-fluorinated vinyl monomers have only been reported. Thus, using radiation-induced polymerization, in which initiating species (radicals) can be continuously produced, the polymerization of trifluorovinyl heptafluoropropyl ether (FVPE) was examined to afford high molecular weight polymers of FVPE. The formation of FVPE homopolymers was confirmed by NMR and IR spectroscopy.

Study of hydraulic behavior for reactor upper plenum in sodium-cooled fast reactor; Verification analysis of water experiment and applicability of vortex prediction method

Fujii, Tadashi; Chikazawa, Yoshitaka; Konomura, Mamoru; Kamide, Hideki; Kimura, Nobuyuki; Nakayama, Okatsu; Ohshima, Hiroyuki; Narita, Hitoshi*; Fujimata, Kazuhiro*; Itooka, Satoshi*

JAEA-Research 2006-017, 113 Pages, 2006/03

JAEA-Research-2006-017.pdf:14.98MB

A conceptual design study of the sodium-cooled fast reactor is in progress in the Feasibility Study on Commercialized Fast Reactor Cycle Systems. Reduced scale water experiments are being performed in order to clarify the flow pattern in the upper plenum of the reactor which has higher velocity condition than the past design. In this report, the hydraulic analyses of the water experiments using the general-purpose thermal hydraulic analysis program were executed; and the applicability to evaluation of flow pattern and vortex cavitations for the designed reactor was examined. (1) Steady-state analyses under the Froude number similar condition were carried out for the 1/10th reduced scale plenum experiments. Analyses results reproduced the characteristic flow patterns in the upper plenum, such as gushed flow from the inside of the upper internal structure to reactor vessel wall and the jet flow from the slit of the upper internal structure. Further, it was confirmed that the calculated flow pattern of a designed reactor system agreed with that of the water experiment qualitatively. Moreover, the influence which setting of numerical solution and boundary condition etc. in analyzing causes to flow pattern in the plenum became clear. (2) The distribution of the vortices under the dipped plate region in the 1/10th plenum model was evaluated using the prediction method of a submerged vortex which is based on the stretching vortex theory. In case of the same velocity condition as the reactor, it identified the two vortices which were sucked into the hot leg piping from the cold leg piping wall as the submerged vortex cavitations. From this analysis result, it confirmed that the submerged vortex cavitations, which may occur in the reactor upper plenum steadily, could be identified using this prediction method.

On the radiation-induced polyaddition of bisperfluoroisopropenyl terephthalate with 1,4-dioxane

Enomoto, Kazuyuki*; Narita, Tadashi*; Maekawa, Yasunari; Yoshida, Masaru; Hamana, Hiroshi*

Journal of Fluorine Chemistry, 125(7), p.1153 - 1158, 2004/07

https://doi.org/10.1016/j.jfluchem.2004.03.003

Radical polyaddition of bis(-trifluoromethyl-,-difluorovinyl) terephthalate (BFP) with 1,4-dioxane (DOX) afforded higher molecular weight polymers under -rays compared to those yielded by benzoyl peroxide initiation. More detailed study on the radiation-induced polyaddition of BFP with DOX and optimization of the reaction conditions were carried out. It was necessary to irradiate with doses of 2000, 1500, and 750 kGy, to obtain quantitative conversion of BFP at the feed molar ratio DOX/BFP of 8.0, 16, and 32, respectively. Step-growth polymerization mechanism was suggested by the measurements of molecular weights of the polymers obtained with several irradiation doses. It was concluded that the molecular weight of the polymer could be controlled by the feed molar ratio of DOX/BFP and irradiation doses. The reaction between polymers might take place after the quantitative conversion of BFP. Radiation-induced radical polyaddition mechanism of BFP with DOX was proposed.

Radiation-induced reactions the lowest excited states in cinnamic acid crystals

Maekawa, Yasunari; Inaba, Tomonori; Hobo, Hiroki; Narita, Tadashi*; Koshikawa, Hiroshi; Moon, S.; Kato, Jun; Yoshida, Masaru

Chemical Communications, (18), p.2088 - 2089, 2002/09

Radiation-induced reactions of cinnamic acid derivatives have been examined and compared them with photoreactions in the crystalline states; all the reaction products were exactly the same as those of the photoreactions, indicating that the reactions proceed only via the lowest excited state to give [2+2]cycloadducts, E/Z isomerization products, or starting molecules.

Ozone catalytic oxidation of o-xylene in air under electron beam irradiation

Matsumoto, Kanae; Shimada, Akihiko; Hakoda, Teruyuki; Narita, Tadashi*; Kojima, Takuji

no journal, , 

no abstracts in English

Oxidation of xylene in air using TiO under electron beam irradiation

Matsumoto, Kanae; Hakoda, Teruyuki; Kojima, Takuji; Hirota, Koichi; Narita, Tadashi*

no journal, , 

no abstracts in English

Preparation of polymer electrolyte membranes for fuel cells by radiation induced-graft polymerization of thermostable aromatic polymers

Sato, Ken; Narita, Tadashi*; Takahashi, Shuichi; Hasegawa, Shin; Maekawa, Yasunari

no journal, , 

Radiation-grafting technique has been applied for the preparation of polymer electrolyte membranes of super engineering plastics, PES and PEEK. The radiation grafting of styrene on to a PEEK film proceeded to give grafted films (PEEK-g-Sty). The milder sulfonation condition of PEEK-g-Sty lead sulfonated PEEK-g-Sty with controlled sulfonation degrees and promising ion exchange capacity(IEC). By controlling graft and sulfonation degrees, PEEK films were transformed into the polymer electrolyte membranes exhibiting proton conductivity of 0.001 - 0.01 S/cm.

Graft polymerization of poly(ether ether ketone)s for fuel cell application; Enhancement of grafting degrees by crystallinity control

Hasegawa, Shin; Takahashi, Shuichi; Sato, Ken*; Narita, Tadashi*; Iwase, Hiroki; Koizumi, Satoshi; Maekawa, Yasunari

no journal, , 

Radiation grafting of ethyl styrylsulfonate (EtSS) onto poly(ether ether ketone) (PEEK) film with various crystallinity was performed. The crystallinity in the range of 10 30% has strong influence on the grafting degrees. The PEEK film with crystallinity of 11% did now show any dose effect on grafting degrees but those with about 20 25% showed increases of grafting degrees with more than 80%. As a result, by increasing the crystallinity from 11 to 26%, the ion conductivity of the resulting electrolyte membranes increased from 0.01 S/cm to 0.08 S/cm, which is higher than that of Nafion.