Origin of the unusually strong and selective binding of vanadium by polyamidoximes in seawater.

Amidoxime-functionalized polymeric adsorbents are the current state-of-the-art materials for collecting uranium (U) from seawater. However, marine tests show that vanadium (V) is preferentially extracted over U and many other cations. Herein, we report a complementary and comprehensive investigation integrating ab initio simulations with thermochemical titrations and XAFS spectroscopy to understand the unusually strong and selective binding of V by polyamidoximes.

Kinetics of complexation of V(v), U(vi), and Fe(iii) with glutaroimide-dioxime: studies by stopped-flow and conventional absorption spectroscopy.

Uranium extracted from seawater is a promising source of uranium for nuclear energy, and the extraction technology using polymer sorbents has been shown to be feasible. However, improving selectivity for uranium over other metals, notably vanadium and iron, is essential to increase efficiency and reduce costs. In the present work, the kinetics of the binding of these three metals with glutaroimide-dioxime as a molecular analogue of polymer sorbents has been studied using stopped-flow and conventional UV Visible absorption spectroscopy to monitor the reactions over a range of time scales.