A simplified radiation-induced emulsion graft polymerization (SREG) method is proposed. This method involves a convenient and easy degassing process of a monomer solution using a commercially available sealed glass jar. A loaded weight on the lid of the jar was used to control the jar’s internal pressure as the degassing of the monomer solution took place using a vacuum pump. The degassing method was highly reproducible, resulting from no bumping of the monomer solution. The initial grafting velocity was proportional to the absorbed doses of pre-irradiation between 5 and 20 kGy. This result indicates that dissolved oxygen was sufficiently eliminated from the monomer solution at such a level where the remaining oxygen had little effect on the grafting reaction at a dose of 5 kGy. The method was then applied to the fabrication of a heavy metal adsorbent that possessed a sufficient adsorption capacity of Co(II) ions. The SREG method is applicable to the fabrication of a wide variety of functional graft polymers because high-dose-rate gamma-ray radiation and expensive experimental equipment are not necessary.
20 September 2023 in Radiation Physics and Chemistry
In this manuscript, we present the successful attachment of crown ether moieties onto fluoropolymer surfaces, via the combination of radiation-induced graft polymerization and a subsequent surface Kabachnik–Fields three-component reaction. The obtained crown ether-tethered fluoropolymer films exhibited an ammonium cation capturing ability, owing to the host–guest interactions (i.e., hydrogen bonding) between the surface-anchored crown ethers and the guest ammonium cations.
1 February 2022 in Radiation Physics and Chemistry
In the fields of polymer and material chemistries, strong acid units have mainly included sulfonic acids, which has limited the extension of related material chemistries. Here, a unique carbon acid functionality, namely the bis[(trifluoromethyl)sulfonyl]methyl group, was integrated with polymers via a simple postpolymerization modification with the outstandingly electrophilic 1,1-bis[(trifluoromethyl)sulfonyl]ethylene. The proposed synthesis protocol was verified as an efficient process even for solid-state reactions. The synthesis afforded an organic material with a surface decorated with bis[(trifluoromethyl)sulfonyl]methyl units. The fabricated membranes featuring surface bis[(trifluoromethyl)sulfonyl]methyl units functioned as efficient organocatalysts with high catalytic activity for the Mukaiyama aldol reaction. This study provides a simple method for installing superacidic carbon acid moieties onto the surfaces of materials without tedious chemical treatments.