New surprise for metal-binding polymer

Abstract

The world’s oceans contain more than 4 billion tons of uranium, an amount that could supply fuel for nuclear power production for centuries. The trick is how to harvest the metal ions, which occur at a dilute 3.3 ppb in the vast and deep blue sea. Chemists have long been developing polymeric materials that selectively absorb uranium, gold, and other valuable metals from seawater. For uranium, researchers have focused on sorbent mats made from poly(amidoxime)s in which the nitrogen-oxygen functional groups in the polymers selectively bind uranium ions. In a new study, Alexander S. Ivanov of Oak Ridge National Laboratory (ORNL) and coworkers report a nuance in this chemistry: poly(amidoxime)s actually bind vanadium ions better than uranium ions. This observation could lead to developing better materials for plucking uranium out of seawater, Ivanov says, but also help in efforts to mine the oceans for metals like vanadium and lithium, which