Robust flexible poly(amidoxime) porous network membranes for highly efficient uranium extraction from seawater

The oceans contain 4.5 billion tons of uranium which can supply almost infinite nuclear energy. However, it is an urgent need to develop adsorbents simultaneously possessing enhanced efficiency, collect ability, durability and economy to massively extract uranium from seawater. Herein, a simple two-step process is designed to massively produce pure poly(amidoxime) porous network membranes (PAO PNMs) which exhibit high uranium uptake capacity and excellent mechanical strength. The resulting membranes display high hydrophilicity, flexibility, strength (16.98 MPa tensile strength), stiffness (0.55 GPa Young's modulus), and porosity (3D porous network structure) which arise from a modified phase separation technique, providing the membranes a very high adsorption efficiency of 707 ± 5.8 mg-U/g-Ads in 8 ppm uranium spiked seawater and 9.35 ± 0.47 mg-U/g-Ads in natural seawater, respectively. Furthermore, the membranes exhibit a long service life of over 10 cycles of adsorption-desorption, and they can be massively produced via this facile phase separation technique by being simply immersed in water. Overall, coupled with the techno-economic advantages, these PAO PNMs are promising in industrial uranium extraction from seawater due to their robustness, high-efficiency and low-consumption.