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[en] Highlights: • Hybrid nanoparticles were synthesized via soap-free seeded emulsion polymerization. • Simultaneous surface functionalization with two ionic comonomers was carried out. • 4-styrenesulfonic acid sodium salt hydrate & potassium methacrylate used as comnomers. • Results showed that the adjusting population of surface charge groups is plausible. • Semi-continuous emulsion polymerization lets incorporation of various comonomers.
[en] According to the present invention, there is provided an apparatus for the continuous production of cured rubber sheets having a surface design comprising: means for extruding rubber into a soft, viscous rubber strip: rotating molding means having the selected design formed in recesses on its surface for receiving the soft, viscous rubber; means for forcing the rubber into recesses; means for directing a beam of high energy ionizing radiation into the viscous rubber to cure the rubber; and means for removing the cured rubber from the recesses. (auth)
[en] Polyacrylonitrile can be synthesized within the micropores of zeolites Beta and ZSM-11 by irradiating gamma ray to the zeolites, on which acrylonitrile monomer was already adsorbed. Alternatively, it can be carried out by heating such zeolites which have impregnated azobisisobutyronitrile as initiator. The resultant composite was analyzed using Thermo Gravimetric Analysis, Differential Scanning Calorimetry and Fourier Transform Infrared Spectroscopy. It was found that framework topology, particularly the pore size limitation, strongly effects polymerization reaction and also thermal degradation behavior of the polymer formed
[en] Two pheomelanin model compounds were prepared and their photochemistries examined. Upon irradiation, an oxygen-mediated photopolymerization reaction was observed. The photopolymers obtained were characterized by their apparent molecular weights, UV and fluorescence spectra. The implications of these findings with respect to the structure and photobiology of pheomelanin are discussed. (author)
[en] Complete text of publication follows. We have developed a new type of radiation dosimeter which is based on radio-fluorogenic co-polymerization 'RFCP'. In this method the dosimeter consists of a liquid monomer which polymerizes when exposed to high energy radiation, for example methylmethacrylate. Dissolved in this bulk monomer is a small (ca millimolar) concentration of a compound that is non-fluorescent but which becomes fluorescent when it is incorporated into a growing polymer chain. The resulting fluorescence is then proportional to the yield of initiating free-radicals formed and hence to the accumulated radiation dose. The method is illustrated by application to remote, real-time dose monitoring within a small (< 0.2 ml) volume. Using a semi-rigid gel form of the RFCP dosimeter, two and three dimensional fluorescent images of a masked 3 MeV electron beam and a 6 MeV X-ray beam have been created.
[en] This research is focused on improving the efficiency of the anion exchange process for purifying plutonium. While initially focused on plutonium, the technology could also be applied to other ion-exchange processes. Work in FY17 focused on the improvement and optimization of porous foam columns that were initially developed in FY16. These foam columns were surface functionalized with poly(4-vinylpyridine) (PVP) to provide the Pu specific anion-exchange sites. Two different polymerization methods were explored for maximizing the surface functionalization with the PVP. The open-celled polymeric foams have large open pores and large surface areas available for sorption. The fluid passes through the large open pores of this material, allowing convection to be the dominant mechanism by which mass transport takes place. These materials generally have very low densities, open-celled structures with high cell interconnectivity, small cell sizes, uniform cell size distributions, and high structural integrity. These porous foam columns provide advantages over the typical porous resin beads by eliminating the slow diffusion through resin beads, making the anion-exchange sites easily accessible on the foam surfaces. The best performing samples exceeded the Pu capacity of the commercially available resin, and also offered the advantage of sharper elution profiles, resulting in a more concentrated product, with less loss of material to the dilute heads and tails cuts. An alternate approach to improving the efficiency of this process was also explored through the development of a microchannel array system for performing the anion exchange.