Search for: All records

Abstract Radioactive pertechnetate (TcO₄⁻) from the nuclear fuel cycle presents a severe risk to the environment due to its large solubility in water and non‐complexing nature. By utilizing the chaotropic properties of TcO₄⁻and its nonradioactive surrogate perrhenate (ReO₄⁻) and the principle of chaotropic interactions, a series of quaternary ammonium‐containing polyelectrolyte brush‐grafted silica particles are designed and applied to remove ReO₄⁻from water. These cationic hairy particles (HPs) are synthesized by surface‐initiated atom transfer radical polymerization of 2‐(N,N‐dimethylamino)ethyl methacrylate and subsequent quaternization with various halogen compounds. Dynamic light scattering (DLS) studies showed that the HPs with sufficiently longN‐alkyl andN‐benzyl substituents underwent sharp size reduction transitions in water when titrated with a KReO₄solution, indicating strong chaotropic interactions between the brushes and ReO₄⁻. All the HPs exhibited fast adsorption kinetics; the HPs with longerN‐alkyl andN‐benzyl substituents showed higher capabilities of removing ReO₄⁻than those with shorterN‐alkyls. Moreover, the brush particles with longerN‐substituents displayed a significantly stronger ability in selective adsorption of ReO₄⁻than the particles with shorterN‐substituents in the presence of competing anions, such as F⁻, Cl⁻, NO₃⁻, and SO₄²⁻. This work opens a new avenue to design high‐performance adsorbent materials for TcO₄⁻and ReO₄⁻.