Abstract
Radiation-induced graft polymerization provides industrially superior functionalization schemes by selection of existing polymer substrates and design of graft chains. In this review, by a pre-irradiation method of the radiation-induced graft polymerization and subsequent chemical modifications, charged polymer chains grafted onto various components and shapes of the polymer substrates are described. The charged graft chains immobilized onto a porous hollow-fiber membrane captured proteins in multilayers via multipoint binding. A membrane onto which positively charged graft chains are immobilized, i.e., an anion-exchange porous hollow-fiber membrane, was commercialized in 2011 for the removal of undesirable proteins in the purification of pharmaceuticals. On the other hand, a membrane onto which negatively charged graft chains are immobilized, i.e., a cation-exchange porous hollow-fiber membrane, exhibited a low permeation flux for pure water; however, the prepermeation of an aqueous solution of magnesium chloride through the membrane restored the permeation flux because of ionic crosslinking of graft chains with magnesium ions. The charged graft chains provide a precipitation field for inorganic compounds such as insoluble cobalt ferrocyanide. The graft chains entangle or penetrate a precipitate owing to electrostatic interactions with the surface charge on the precipitate. Braids and wound filters composed of insoluble-cobalt-ferrocyanide-impregnated fibers are used for the removal of radiocesium from contaminated water at Tokyo Electric Power Co. (TEPCO) Fukushima Daiichi Nuclear Power Plant.
Highlights
Introduction of RadiationInduced Graft PolymerizationRadiation-induced graft polymerization was first reported in the 1950s [1,2,3] and was considered a promising technique to modify polymeric materials
By combining the polymeric materials and polymer branches, radiation-induced graft polymerization provides us with facile design of desirable and useful functional materials
We focused on the pre-irradiation graft polymerization method because it is advantageous in that the formation of ungrafted polymer can be limited and a graft-polymerization is independently processed from an irradiation step, leading to promoting the industrial production of polymer chain-grafted materials
Summary
Radiation-induced graft polymerization was first reported in the 1950s [1,2,3] and was considered a promising technique to modify polymeric materials. Radiation-induced radical polymerization is widely applicable to various components and shapes of polymeric materials compared with other grafting techniques [4,5,6,7,8,9]. This allows us to select polymer substrates in terms of specific applications. By cleaving covalent bonds with radiation irradiation, chemists form graft sites (radicals) in polymeric materials suitable for specific applications. Radicals are unpaired electrons and generally show high chemical reactivity They graft a polymer branch with suitable capabilities. By combining the polymeric materials (substrates) and polymer branches (graft chains), radiation-induced graft polymerization provides us with facile design of desirable and useful functional materials
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
