Direct removal of
99
TcO
4
–
from alkaline nuclear
waste is desirable because of the nuclear
waste management and environmental protection relevant to nuclear
energy but is yet to be achieved given that combined features of decent
base-resistance and high uptake selectivity toward anions with low
charge density have not been integrated into a single anion-exchange
material. Herein, we proposed a strategy overcoming these challenges
by rationally modifying the imidazolium unit of a cationic polymeric
network (SCU-CPN-4) with bulky alkyl groups avoiding its ring-opening
reaction induced by OH
–
because of the steric hindrance
effect. This significantly improves not only the base-resistance but
also the affinity toward TcO
4
–
as a result
of enhanced hydrophobicity, compared to other existing anion-exchange
materials. More importantly, SCU-CPN-4 exhibits record high uptake
selectivity, fast sorption kinetics, sufficient robustness, and promising
reusability for removing
99
TcO
4
–
from the simulated high-level waste stream at the U.S. Savannah
River Site, a typical alkaline nuclear waste, in both batch experiment
and dynamic column separation test for the first time.
This feature article reviews the development of functionalized pillararenes as supramolecular materials for lanthanide and actinide separation and heavy metal removal.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.