Tough polyamidoxime-nanocellulose supramolecular composite hydrogels for effective uranium extraction from seawater

It is highly desirable to synthesize high-performance composite hydrogels in a simple and economical manner for uranium extraction from seawater. In this study, tough polyamidoxime-nanocellulose (PAO-CNF) composite hydrogels are fabricated via supramolecular complexation. The nanostructured PAO domains are dispersed in the supramolecularly cross-linked CNF network, guaranteeing superior mechanical strength and satisfied uranium uptake in seawater. A high tensile strength of 4.3 MPa is retained for the composite hydrogels after immersion in seawater for 30 days, which is beneficial for long-term survival in the ocean. The uranium uptake capacity reaches 6.6 mg-U/g in seawater after 35-day adsorption, a synergistic effect from nanostructured PAO domains and hydrophilic CNF network. The tough supramolecular composite hydrogels have great potentials for uranium extraction from seawater, enabling sustainable development of energy and environment.