Designing self-adaptative cyclized polyacrylonitrile-polyethyleneimine conjugates enhance uranium extraction from natural seawater
Ying Wang, Ruolan Zhao, Yachao Xu, Peng Yu, Shifang Yang, Yue Qu, Rongjuan Feng, Mingyi Zhang, Youxing Liu
Abstract
Uranium extraction from seawater offers a promising route to secure sustainable nuclear fuel and mitigate environmental issues from fossil fuel consumption, yet it remains hindered by low extraction efficiency and severe biofouling. Herein, we report a self-adaptative adsorbent—cyclized polyacrylonitrile–polyethyleneimine (CPAP)—which undergoes conformation expansion in alkaline seawater to enhance uranium uptake and contracts in acidic solution to facilitate uranium desorption. CPAP exhibits a high adsorption capacity of 22.3 mg g-1, outperforming all reported fiber-based adsorbents. Its excellent photothermal effect combined with quaternary ammonium functionalities effectively suppresses biological adhesion. Mechanistic studies reveal that electrostatic repulsion and hydrogen bonding drive pH-responsive structural transitions. Furthermore, a self-designed flow-type extraction device demonstrates high uranium extraction efficiency (1.91 mg g-1d-1) and excellent cycling stability, underscoring the practical scalability of this strategy. Overall, This work introduces a self-adaptative concept materials for enhancing seawater uranium harvesting, opening the door to fundamental research on designing intelligent adsorbent. Uranium extraction is necessary to power nuclear reactors, though it is challenging to extract uranium from seawater. Here the authors design a polyacrylonitrile-polyethyleneimine adsorbent to extract uranium from seawater.