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Nowadays, large-scale oriented functional porous materials have been sought after by researchers. However, regulation of the long-range uniform and oriented structures of the material remains a challenge. Herein, ultralong anisotropic cellulose nanofibril (CNF) aerogels with uniformly ordered structures of pore walls inspired by lotus petioles were constructed by applying external speeds to counterbalance the growth driving forces of ice crystals. Based on the growth law of ice crystals, the ice crystals grew at a stable rate when the applied external speed was 0.04 mm/s, ensuring the consistent orientation of the large-scale CNF aerogel. The aerogel exhibited a rapid long-range directional transport ability to different liquid solvents, delivering ethanol up to 40 mm from bottom to top within 50 s. Moreover, by introducing rectorites with good cation-exchange properties, the resulting long-range composite possessed an enhanced adsorption capacity for methylene blue. Furthermore, aerogel successfully achieved realtime dye purification at a long distance, such as fast dye adsorption or selective adsorption. This flexible and straightforward strategy of fabricating ultralong oriented CNF aerogel materials is expected to promote the development of functional aerogels in directional liquid transport and sewage treatment.

The facile fabrication of thin flexible electromagnetic interference (EMI) shielding materials with fast heat dissipation for adaptable tuning in both civil and military applications is in urgent demand. In our work, the flexible poly(vinylidene fluoride) (PVDF)/carbon nanotube (CNT) composite films decorated with anisotropy-shaped Co in flowers or chains were prepared and studied. The results showed that by increasing the Co filler contents, the EC (electrical conductivity), TC (thermal conductivity), and EMI shielding properties of such PVDF/CNT/Co (flowers or chains) flexible films were significantly improved. In contrast, the PVDF/CNT/Co-chain flexible films exhibit higher performance with respect to the EC, TC, and EMI shielding properties. Total shielding of 35.3 and 32.2 dB were, respectively, obtained by the PVDF/CNT/6 wt % Cochain with an EC of 2.28 S/cm and the PVDF/CNT/6 wt % Co-flower with an EC of 1.94 S/cm at a film thickness of 0.3 mm. Possibly owing to the conductive dissipation, interfacial polarization, magnetic loss, multiple reflections, and scattering of EM waves, such flexible composite films possessed a remarkable absorption-dominated EMI shielding behavior. These new composite films with enhanced TC are easily able to transform microwave energy into Joule heating systems, making themselves greatly potential for effective EMI shielding as well as rapid heat dissipation.

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A flaky Fe-based mangetorheological elastomer film (F-Fe/MREF) composite was developed through mixing micronsized flaky Fe particles into a silicone rubber (SR) matrix by compression molding and vulcanization. The 28 wt % F-Fe/MREF with a thickness of 4.3 mm displays dual resonance peaks with an optimal reflection loss (RL) value of −53.3 dB at 4.8 GHz and an effective frequency bandwidth (RL < −10 dB) reaches 6.0 GHz. Furthermore, anisotropic F-Fe/MREF obtained by assistance of an external magnetic field demonstrates an effective bandwidth of 12.5 GHz in one thickness. This is attributed to the synergistic contributions from magnetic loss and dielectric loss and good impedance matching along with promotion of multiple reflections and scatterings. Besides, an MR effect of 39.2% was obtained for anisotropy F-Fe/MREF because of interaction enhancement between F-Fe particles and the cross-linked matrix. These results suggest that the F-Fe/MREF composites could serve as a potential candidate toward applications of electromagnetic wave absorbing.