Shun'ichi Sugimoto

Irradiation effects of excimer laser radiation and electron beam on polypropylene and ethylene-tetrafluoroethylene copolymer films

Abstract The irradiation effects of the intense ultraviolet radiation from an excimer laser on polypropylene (PP) and ethylene-tetrafluoroethylene (ETFE) copolymer films are compared with those from electron beam studies. Irradiation of PP films with a KrF laser and an electron beam induced the degradation of the polymer, and use of an ArF laser selectively decomposed the alkyl phenol type additive contained as an antioxidant in PP instead of degrading the polymer. Irradiation with a KrF laser induced the carbonization of ETFE copolymer due to polymer degradation, and irradiation with an ArF laser and an electron beam formed ue5f8Cue5fbO and ue5f8Cue5fbCue5f8 groups in the polymer chains.

Radiation-induced chemical reactions of carbon monoxide and hydrogen mixture. I: Electron beam irradiation at atmospheric pressure

Abstract The radiation chemical reaction of Coue5f8H2 mixture has been studied in the pressure range from 104 to 1.3×105 Pa using 7 1. reaction vessel made of stainless. Various hydrocarbons and oxygen containing compounds such as methane, formadehyde, acetaldehyde, and methanol have been obtained as radiolytic products. The amounts and the G values of these products depended upon the irradiation conditions such as composition of reactant, total pressure, reaction temperature, and dose. It was found that the irradiation at low dose produced small amounts of trioxane and tetraoxane, which have not yet been reported in literature. The yields of these cyclic ethers increased at high pressure and at low temperature. An experiment was also made on Coue5f8H2 mixture containing ammonia as a cation scavenger to investigate the precursor of these products.

Radiation-induced chemical reactions of carbon monoxide and hydrogen mixture. II: Effects of reactant pressure and temperature on the yields of oxygen containing products

Abstract The radiation chemical reaction of CO-H2 mixture up to 8.4 x 105 Pa has been studied. The G values of oxygen containing organic compounds except methanol increased with increasing total pressure of reactant. The G values of most of products except trioxane and tetraoxane were increased with raising of temperature in the range from 210 to 350 K, while the G values of trioxane and tetraoxane reached the maxima at 243 K and decreased rapidly with raising of temperature. From the dependencies of G values of these cyclic ethers on pressure and temperature of the reactant, it is considered that these cyclic ethers produced from the neutralization reaction of HCO+ (CO)n cluster ions with electrons in an atmosphere of relatively large amount of hydrogen. The effects of CO content on G values of products did not change with the pressure change of the reactant.

The γ-ray-induced reactions of carbon monoxide-hydrogen mixtures at elevated pressures

Abstract The γ-irradiation of COue5f8H 2 mixture has been studied in the pressure range from 5 × 10 6 Pa to 6.9 × 10 6 Pa in an autoclave made of stainless steel. Hydrocarbons and oxygen containing compounds such as formaldehyde and acetaldehyde were identified as radiolytic products. The amounts of products increased with increasing pressure. The effects of dose, irradiation temperature, and reactant composition on the amounts of products were also reported.

High enrichment of 28Si by infrared multiple photon decomposition of Si2F6

High enrichment of 28Si has been carried out using the laser isotope separation technique based on the isotopically selective infrared multiple photon decomposition of Si2F6. When about 2 Torr of Si2F6 was irradiated at a fluence of 1.0 J/cm2 per pulse with the 10P(8) line of a TEA CO2 laser at 954.55 cm-1, the compound decomposed very efficiently with high isotope selectivity. The products SiF4 and white solids were enriched with 29Si and 30Si, while the residual Si2F6 was enriched with 28Si. The atomic fraction of 28Si in residual Si2F6 increased with increasing decomposition of Si2F6; 99.9% of 28Si was obtained at a consumption of 50% of initial Si2F6. The large-scale flow experiment yielded 99.7% 28Si at a production rate of 2.5 g/h, where a mixture of 3.3 Torr Si2F6 and 6.6 Torr argon was irradiated with 10P(8) laser pulses at a repetition rate of 5 Hz. Merits and demerits of the present laser separation are discussed in comparison to those of conventional separation methods. Laser enrichment of 28Si seems promising for economical production of large quantity of pure 28Si. Various applications of silicon isotopes are briefly reviewed.

Radiation-induced chemical reactions of carbon monoxide and hydrogen mixture—IV. On the water produced by the addition of small amounts of ammonia

Abstract The isotope content in water obtained from irradiated CO-H2 mixture with added small amounts of NH3 or their deuterated equivalents was compared. Compared with that in water obtained from CO-D2 mixture with added NH3, D content in water produced from the mixture with the substitution of ND3 for NH3 was increased remarkably. The NH3 added to the mixture contributes to the water formation under irradiation.

Fischer-Tropsch reaction on iron catalysts prepared by electron beam implantation on Kapton film

Abstract Electron beam irradiation of an Ar-iron pentacarbonyl gas mixture in the presence of a Kapton film has been carried out and the catalytic activity via the Fischer-Tropsch reaction on the irradiated Kapton film was investigated. The electron beam irradiation resulted in the deposition of iron on the Kapton film surface. Most of the deposited iron was removed when the film was immersed in aqueous hydrochloric acid solution, but a small amount of iron remained undissolved, indicating that iron was implanted in the Kapton film (electron beam implantation) and contributed to the catalytic activity via the Fischer-Tropsch reaction. The activity increased with increasing electron energy of implantation above 400 keV, but no activity was found when the irradiation was carried out below this energy.

Radiation-induced chemical reactions of carbon monoxide and hydrogen mixture— V. Increase in product yields due to the addition of methane

Abstract When the CO-H 2 mixture containing 1 mol% CH 4 at 6.6 × 10 5 Pa in total pressure was irradiated by electron beam, the G values of trioxane and tetraoxane increased remarkably compared with those obtained by the irradiation of the CO-H 2 mixture in the absence of CH 4 . The result suggests that in the presence of CH 4 , the cyclic ethers are produced by the neutralization reaction of the cluster ion containing CH 4 , CH + 4 (CO) n , with electron. The G values of aldehydes and carboxylic acids constituted of C 2 or more carbon atoms, increased by the addition of CH 4 of 20 mol% or more. It is considered that the increase in the G values of these aldehydes and carboxylic acids by the addition of CH 4 was caused by the contribution of the acyl radicals, RCO, which formed by the reaction of hydrocarbon radicals produced from added CH 4 and CO.

Radiation-induced chemical reactions of carbon monoxide and hydrogen mixture—III. Solid materials produced under irradiation

Abstract Three varieties of nonvolatile solid products A, B, and C were obtained from the CO-H 2 mixtures irradiated by electron beam in different conditions. Solids A and B were obtained as a deposit on the wall of reaction vessel from the mixture containing 15 and 78 mol % CO, respectively. The solid C was obtained as the deposit in the cold traps set in the path of reactant (15 mol% CO) circulation. From the analyses by IR, GC, and mass spectrometer and characteristics of these solids, it was suggested that the solid A was the substance formed from the reaction of HCHO with carboxylic acid, the solid B was C 3 O 2 polymer having low molecular weight, and the solid C was paraformaldehyde.