Aromatic Amine/Diketene-Adduct-Modified Poly(ethylenimine): Facile One-Pot Tandem Reaction Preparation for High-Efficiency Iodine Capture

Abstract

As an efficient energy source, nuclear energy plays an increasingly important role in current energy composition. However, the radioactive nuclides retained in nuclear waste, especially 129I and 131I, pose potential threats to the ecological environment. In this study, tris(4-aminophenyl) amine (TAPA), diketene (DK), and poly(ethylenimine) (PEI) were used as reaction substrates, and the reactivity differences between arylamine/alkylamine with DK were rationally addressed. The polymer (DK-TAP) with multiple N/O-containing units (amide/enamine/tertiary amine) and aromatic fragments was successfully synthesized through a one-pot and catalyst-free aromatic amine-DK-alkyl amine multicomponent tandem reaction (ADA-MCTR) at room temperature. The characterization of the chemical structure and basic physicochemical properties of DK-TAP indicates that it is a type of amorphous, cross-linked polymer. DK-TAP can effectively adsorb iodine in gaseous, organic, and aqueous phases, and its saturated adsorption capacities were recorded as 6.73 g g–1 (gas phase), 3.20 g g–1 (cyclohexane phase), and 3.22 g g–1 (I2/KI aqueous phase), respectively. Adsorption mechanism analysis indicates that the commendable iodine capture performance of DK-TAP is attributed to the synergistic charge transfer between N/O heteroatom units and aromatic fragments in its skeleton with iodine.