Impregnation structure of cobalt ferrocyanide microparticles by the polymer chain grafted onto nylon fiber

Abstract

At Tokyo Electric Power Company (TEPCO) Fukushima Daiichi nuclear power plant (NPP), water contaminated with radionuclides such as Cs-137 and Sr-90 has been stored in tanks and seawaterintake area. We have prepared cobalt-ferrocyanide-impregnated fibers via four steps: the grafting of an epoxy-group-containing monomer, the conversion of the epoxy group into positively charged groups, the binding of ferrocyanide ions ([Fe(CN) 6 ] 4− ), and the precipitation of cobalt ferrocyanide (Co 2 [Fe(CN) 6 ]) by contact with cobalt ions. However, the impregnation structure of cobalt ferrocyanide microparticles onto the fiber remains unclear. Here, we describe the impregnation structure from the results of rebinding [Fe(CN) 6 ] 4− to the cobalt-ferrocyanide-impregnated fiber. The amount of [Fe(CN) 6 ] 4− re-bound onto the fiber was found to decrease with increasing amount of Co 2 [Fe(CN) 6 ] initially impregnated. This suggests that the microparticles of cobalt ferrocyanide become entangled with the grafted polymer chains via multipoint electrostatic interactions.

Development of a Simplified Radiation-Induced Emulsion Graft Polymerization Method and Its Application to the Fabrication of a Heavy Metal Adsorbent

“…To solve the problem concerning the dissolved oxygen during emulsion graft polymerization as mentioned in “Introduction,” we introduced a new method, SREG, as shown in Scheme 1. GMA was chosen as a grafting agent, as it could be easily converted to structures having various functions [21,22,23,24,25,26,27]. The process is as follows: (a) The preirradiated PE/PP fabric was set in the commercially available sealed glass jar, made up of the glass lid, the rubber packing, and the jar itself.…”

Recent Progress in Charged Polymer Chains Grafted by Radiation-Induced Graft Polymerization; Adsorption of Proteins and Immobilization of Inorganic Precipitates

“…The CoFC precipitate formed in the graft chain did not leak into the external liquid when the pH and ionic strength of the liquid varied in the ranges of 0 to 13 and 0 to 1.0 mol/L, respectively, and when rubbing stress was applied by hand. This stable immobilized structure is ascribed to the entanglement and penetration of the CoFC precipitate by the graft chain owing to the electrostatic attraction between the negative surface charge of the CoFC precipitate and the positive charge of the TEDA-moiety-containing graft chain [64].…”

Summary report of recent activities for decontamination and environmental restoration after Fukushima Daiichi nuclear power plant accident

“…For the development of the system for aircooling the nuclear fuel during the accident like FDNPP, numerical study was carried out [22]. For the waste management, estimation of the inventory [23], vitrification for the immobilization of radioactive sludge generated from FDNPP [24], treatment of radioactive Cs by cobalt ferrocyanide microparticles [25], treatment of radioactive-waste-seawater [26] and U separation from a simulant fuel debris [27] were reported. Interestingly, two reviews on the effects of radiation damage on spent fuel (SF) for direct disposal [28,29] were reported.…”