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A new polyvinyl alcohol foam gel/MOF-808 detergent was used to study the uranium removal process on the cement surface, and the mechanism was deeply analyzed. Through the mutual verification of XPS, infrared spectrum, XRD and SEM, it is confirmed for the first time that MOF-808 mainly relies on its own Zr-OH and carboxyl groups to remove uranyl ions in foam gel, rather than the carboxyl groups on the ligand. Foam gel combined with MOF-808 can improve the decontamination factor of cement surface by 37.3%, and the maximum removal rate of uranium pollution on cement surface can reach 68.1%. [ABSTRACT FROM AUTHOR]

In this work, a foam gel material based on polyvinyl alcohol were successfully prepared to remove uranium contamination on the surface of stainless steel. The material was tested through infrared spectroscopy and thermogravimetric analysis. The decontamination process of the foam gel on stainless steel surface was analyzed by SEM/EDS and XPS. The results show that the foam gel has good stripping properties, and its decontamination factor for removal of radioactive uranium on stainless steel surfaces could reach 90.9, which seems better than the methods of water washing and wiping. [ABSTRACT FROM AUTHOR]

The construction of special three-dimensional microstructure is becoming an extremely fascinating approach to upgrade the electromagnetic properties of carbon-based microwave absorption materials (MAMs) recently. Herein, we have demonstrated the successful fabrication of a series of carbon nanotubes (CNTs)@Ni/C foams (CNCFs) through two-step pyrolysis processes. It is found that the loading amount of CNTs has an obvious influence on modulating the electromagnetic diameters of CNCFs, and thus effectively tuning their microwave absorption properties. With the relative carbon content of 66.3 wt%, CNCFs-2 exhibits admirable microwave absorption performance, including the effective absorption bandwidth of 5.8 GHz with the absorber thickness of 1.8 mm and the maximum reflection loss intensity of −47.0 dB therein. Electromagnetic analysis reveals that the intrinsic attenuation ability, well-matched characteristic impedance, and multiple reflection effect synergistically work for the excellent reflection loss characteristics of CNCFs-2, which indicates rational microstructure design and appropriate chemical composition regulation are vitally important for the enhancement of microwave absorption performance. We believe these desirable microwave absorption properties can make CNCFs-2 eligible to be a very promising candidate for high-performance MAMs, and this research will provide some inspirations more or less for the development of more advanced carbon-based MAMs in the future. [Display omitted] [ABSTRACT FROM AUTHOR]