To catalytically dechlorinate PCB-related substances, palladium (Pd) was impregnated onto a nylon6 fiber by radiation-induced graft polymerization and subsequent chemical modifications. Palladium anionic species (PdCl42−) were immobilized to dimethylaminoethyl methacrylategrafted fiber, followed by the reduction of palladium anionic species to palladium with hydrazine at temperatures ranging from −3 to 25°C. 2-Chlorophenol was dechlorinated quantitatively to phenol at a reaction time of 2 h with hydrazine as a hydrogen source using Pd-impregnated fiber prepared at a reduction temperature of −3°C.
The anion-exchange fiber was prepared by radiation-induced emulsion graft polymerization of glycidyl methacrylate (GMA) on a polyethylene (PE) fiber and subsequent chemical modifications. The PE fiber was irradiated with electron beam at various doses ranging from 20 to 200 kGy before GMA was graft-polymerized. Subsequently, the epoxy group of the poly-GMA graft chain was converted into a diethylamino (DEA) group with a molar conversion of 89 to 93％. At the degrees of GMA grafting of 85±8％, the anion-exchange fibers prepared at various doses up to 200 kGy exhibited a molar ratio of amount of Cl adsorbed to DEA group density of unity irrespective of dose. In contrast, the anion-exchange fiber prepared at 20 kGy exhibited 3.4-fold higher amount of bovine serum albumin adsorbed than that prepared at 200 kGy.
Trace light elements such as Li, Be and B in materials are rather difficult to be analyzed than heavier elements. In this review outlines of elemental analysis using MeV ion beams and nuclear reaction analysis are described. As an example, our experimental method of nuclear reaction analysis with using gamma ray induced by MeV energy proton microbeams and some results of mapping of trace boron in iron are presented.
This paper reviewed the current status of food irradiation in the world in 2017. The quantities of irradiated foods are increasing as 550,000 tons in China and 110,000 tons in Vietnam. Phytosanitary irradiation of agricultural products has recently increased. The US has imported 31,000 tons of the irradiated fruits from Mexico and other countries including Hawaii. In Asia and Oceania countries, not only export to the US, but also export and import of irradiated fruits and vegetables within the region such as Australia and Vietnam are developing.