Scalable synthesis of ultralight, multifunctional, and high-temperature resilient ceramic nanofiber sponges by blow-spinning.

electricity on a large scale with ultralow greenhouse gases emission. [2] Uranium is the most critical ingredient for the production of nuclear power. In order for nuclear power to be a sustainable energy generation in the future, economically viable sources of uranium beyond terrestrial ores must be developed. [3] The oceans hold ≈4.5 billion tons of uranium, [4] making them a potential huge resource to support nuclear power production for hundreds of years. [5] All that is required is the ability to capture this element from seawater in cost-and energy-efficient ways. In the last decades, researchers worldwide have tried various methods to recover uranium from seawater and aqueous solution, such as coprecipitation, [6] ion-exchange, [7] adsorption via porous organic polymers, [8,9] and organic-inorganic hybrid adsorbents. [10][11][12][13][14][15][16] Among these technologies, the adsorption approach, particularly by using fiber-based adsorbents, is recognized as the most feasible process in terms of practicality, processability, cost, and environmental concerns. [3,17] In the 1990s, Japan Atomic Energy Agency (JAEA) research teams had successfully captured over 1083 g of uranium directly from ocean by using nonwoven fabric adsorbent, firmly establishing the practicality of uranium recovery from the oceans in appreciable quantities. [3,18] Uranium extraction from seawater via fiber adsorption has recentlyThe oceans contain hundreds of times more uranium than terrestrial ores. Fiber-based adsorption is considered to be the most promising method to realize the industrialization of uranium extraction from seawater. In this work, a pre-amidoximation with a blow spinning strategy is developed for mass production of poly(imide dioxime) nanofiber (PIDO NF) adsorbents with many chelating sites, excellent hydrophilicity, 3D porous architecture, and good mechanical properties. The structural evidences from 13 C NMR spectra confirm that the main functional group responsible for the uranyl binding is not "amidoxime" but cyclic "imidedioxime." The uranium adsorption capacity of the PIDO NF adsorbent reaches 951 mg-U per g-Ads in uranium (8 ppm) spiked natural seawater. An average adsorption capacity of 8.7 mg-U per g-Ads is obtained after 56 d of exposure in natural seawater via a flowthrough column system. Moreover, up to 98.5% of the adsorbed uranium can be rapidly eluted out and the adsorbent can be regenerated and reused for over eight cycles of adsorption-desorption. This new blow spun PIDO nanofabric shows great potential as a new generation adsorbent for uranium extraction from seawater.

Particulate matter (PM) is a major air pollutant in many regions, jeopardizing ecosystems and public health. Filtration at pollutant source is one of the most important ways to protect the environment, however, considering the high-temperature exhaust gas emissions, effective removal of PM and related pollutants from their sources remains a major challenge. In this study, a resilient, heat-resisting, and high-efficiency PM filter based on yttria-stabilized ZrO (YSZ) nanofiber sponge produced with a scalable solution blow spinning process is reported. The porous 3D sponge composed of YSZ nanofibers is lightweight (density of 20 mg cm ) and resilient at both room temperature and high temperatures. At room-temperature conditions, the YSZ nanofiber sponge exhibits 99.4% filtration efficiency for aerosol particles with size in the range of 20-600 nm, associated with a low pressure drop of only 57 Pa under an airflow velocity of 4.8 cm s . At a high temperature of 750 °C, the ceramic sponge maintains a high filtration efficiency of 99.97% for PM under a high airflow velocity of 10 cm s . A practical vehicle exhaust filter to capture particles with filtration efficiency of >98.3% is also assembled. Hence, the YSZ nanofiber sponge has enormous potential to be applied in industry.

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Brain–computer interfaces (BCIs) enable direct and near-instant communication between the brain and electronic devices. One of the biggest remaining challenges is to develop an effective noninvasive BCI that allows the recording electrodes to avoid hair on human skin without the inconveniences and complications of using a conductive gel. In this study, we developed a cost-effective, easily manufacturable, flexible, robust, and gel-free silver nanowire/polyvinyl butyral (PVB)/melamine sponge (AgPMS) electroencephalogram (EEG) electrode that circumvents problems with hair. Because of surface metallization by the silver nanowires (AgNWs), the sponge has a high conductivity of 917 S/m while its weight remains the same. The flexible sponge framework and self-locking AgNWs combine to give the new electrode remarkable mechanical stability (the conductivity remains unchanged after 10 000 cycles at 10% compression) and the ability to bypass hair. A BCI application based on steady-state visual evoked potential (SSVEP) measurements on hairless skin shows that the BCI accuracy of the new electrode (86%) is approximately the same as that of conventional electrodes supported by a conductive gel (88%). Most importantly, the performance of the AgPMS on hairy skin is not significantly reduced, which indicates that the new electrode can replace conventional electrodes for both hairless and hairy skin BCIs and other EEG applications.