Selective and efficient removal of ReO4- from aqueous solution by imidazolium-based porous organic polymers

Creation of Cationic Polymeric Nanotrap Featuring High Anion Density and Exceptional Alkaline Stability for Highly Efficient Pertechnetate Removal from Nuclear Waste Streams

“…A noteworthy observation in the XPS spectrum of CPN-3@ReO 4 – is the emergence of a new peak at 399.8 eV, corresponding to the N + –O – species, providing further confirmation that the primary adsorption sites are the N + moieties within the imidazolium units (Figure f). Similar phenomena have been observed in a published work …”

“…Similar phenomena have been observed in a published work. 55 Density functional theory (DFT) calculations were further conducted to investigate the mechanisms behind the remarkable alkaline stability of CPN-3 and its superior separation capability toward 99 TcO 4 − . In alkaline environments, the nucleophilic reagent OH − is known to preferentially attack the C2 position of imidazolium ions, resulting in the degradation of the imidazolium ring through nucleophilic addition, ring-opening, and rearrangement reactions.…”

Modulating Anion Nanotraps via Halogenation for High-Efficiency 99TcO4–/ReO4– Removal under Wide-Ranging pH Conditions

“…The presence of polymeric C–C bonds in all of the iCOPs was evidenced by the appearance of signals at around 38.4 (peak h) to 42.5 (peak g) ppm in the solid-state 13 C cross-polarization with magic-angle spinning (CP-MAS) NMR spectra, confirming the success of the vinyl addition polymerization (Figure b). Moreover, the 13 C CP-MAS solid-state NMR spectra of iCOPs-1, 2, and 3 showed signals at ∼60 ppm attributed to C–imidazolium–N + bonds, consistent with the FT-IR results . The C–F and C–Br groups were also identified in the 13 C NMR spectra, and thus could be used to “fingerprint” iCOP-2 (C–F, 160 ppm, peak b) and iCOP-3 (C–Br, 125 ppm, peak b) (Figure b). , Scanning electron microscopy (SEM) revealed similar nanosphere morphologies for iCOP-1, iCOP-2, and iCOP-3 (Figure c–e).…”

“…Moreover, the 13 C CP-MAS solidstate NMR spectra of iCOPs-1, 2, and 3 showed signals at ∼60 ppm attributed to C−imidazolium−N + bonds, consistent with the FT-IR results. 63 The C−F and C−Br groups were also identified in the 13 C NMR spectra, and thus could be used to "fingerprint" iCOP-2 (C−F, 160 ppm, peak b) and iCOP-3 (C−Br, 125 ppm, peak b) (Figure 2b). 64,65 Scanning electron microscopy (SEM) revealed similar nanosphere morphologies for iCOP-1, iCOP-2, and iCOP-3 (Figure 2c−e).…”