RESUMEN
Efficient uranium extraction from seawater is critical for the development of the nuclear industry. Herein, a polydopamine/salicylaldoxime decorated hierarchical zeolitic imidazolate framework-8 (H-PDA/SA-ZIF-8) is constructed by using a controlled etching process. Benefiting from the combination of PDA/SA and the zeolitic imidazolate framework-8 (ZIF-8), as well as a controlled etching process, the H-PDA/SA-ZIF-8 possesses multiaffinity sites, excellent specific surface area (1234.92 m2 g-1), and a hierarchical pore structure. The H-PDA/SA-ZIF-8 exhibits excellent adsorption capacity (Qm = 869.6 mg g-1), selectivity, and reusability in uranium adsorption. The adsorption process of H-PDA/SA-ZIF-8 fits very well with the Langmuir isotherm model and pseudo-second-order models, and the adsorption process equilibrates within 20 min (C0 = 20 mg L-1). Furthermore, the H-PDA/SA-ZIF-8 shows remarkable antibacterial ability. Impressively, the adsorption capacity of H-PDA/SA-ZIF-8 to uranium in natural seawater reaches 6.9 mg g-1 after circulation for 15 days. Therefore, the H-PDA/SA-ZIF-8 is a promising and fascinating material for uranium extraction from natural seawater.
RESUMEN
Based on the Dielsâ»Alder reaction and hydroxyl-terminated polybutadiene (HTPB) binders of solid propellants, two novel compounds-furfuryl-terminated polybutadiene (FTPB) and trifurfuryl propane (TFP)-were designed and synthesized, and their structures were characterized. A new kind of reversible Dielsâ»Alder reaction system was formed by FTPB as main resin, N,N'-1,3-phenylenedimaleimide (PDMI) as curing agent and TFP as chain extender. The results showed that this system had good mechanical properties with a tensile strength of 1.76 MPa and a tensile strain of 284% after curing, and the repair efficiency of the crack was 88%. Therefore, it could be used as a novel binder of energetic materials such as solid propellant and PBX explosives to provide them with self-repairing characteristics and improve the reliability for application.