Development of renewable anti-biofouling UHMWPE fiber-based adsorbents functionalized with amidoxime and polyguanidine salt for uranium extraction from seawater

The biological contamination of adsorption materials by marine bacteria can significantly reduce the efficiency of uranium extraction from seawater. During the adsorption-desorption cycles, the antibacterial group structure of the prepared antibacterial adsorbent material tends to degrade, resulting in reduced or complete loss of antibacterial performance. In this study, acrylic acid (AA) and acrylonitrile (AN) were grafted onto the surface of ultra-high molecular weight polyethylene (UHMWPE) fibers through radiation-induced graft polymerization. Subsequently, an aminoximation reaction was carried out, followed by ion exchange, to fabricate a polyguanidine-modified amidoxime-based uranium adsorption material (UE-g-PAO/PHMG). This process not only endows the adsorption material with excellent antibacterial properties (more than 99.4 %) but also introduces a novel approach to maintaining and regenerating the antibacterial performance of adsorbents. Benefiting from the synergistic effect of its functional groups, UE-g-PAO/PHMG achieves remarkable adsorption performance (379 mg/g) and demonstrates high selectivity for uranium over vanadium (U: V = 1.36). Furthermore, UE-g-PAO/PHMG exhibits excellent mechanical strength and extended service life, withstanding at least 10 adsorption-desorption cycles. The well-engineered structure of this material confers exceptional properties, fully meeting the economic evaluation criteria for uranium extraction from seawater (UES). The characteristics of the synthesized adsorbents align with the field adsorption indices critical for uranium extraction from seawater, presenting a promising pathway for marine nuclear fuel production.