Polyamidoxime-based colloidal particles with a 3D network for synergistic uranium extraction from seawater

It is still a challenge to synthesize high-performance adsorbents for uranium extraction from seawater. The stable uranyl tricarbonate complex in seawater seems to preclude coordination of uranyl ions by adsorbents. This study reports 3D networked colloidal particles consisting of polyamidoxime (PAO) and sodium polyacrylate (PAA-Na) segments via competitive conversion between amidoximation and hydrolysis in NaOH aqueous solutions. PAA-Na can promote the dissociation of uranyl ions via ion exchange for high-efficiency coordination by PAO. As a result, the colloidal particles, with high selectivity for uranyl ions, reach an outstanding uranium uptake capacity of 17.8 mg U per g in real seawater after 20-day adsorption.