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The urgent problem to solve is how to design a kind of green and porous adsorbent that can effectively remove dye pollutants in the field of the sewage treatment. The objectives of this investigation are to incorporate zeolitic imidazolate frameworks‐8 (ZIF‐8) particles in situ onto the surface of multiwalled carbon tubes (MWCNTs) and integrate them into an agarose‐sodium alginate (ASA) double network hydrogel. The resulting composite hydrogel beads, denoted as MWCNTs/ZIF‐8/ASA (MZASA), are synthesized using calcium ion crosslinking. The addition of agarose is employed to create a dual‐crosslinked hydrogel, thereby enhancing the mechanical properties of the ASA hydrogel. By incorporating MWCNTs/ZIF‐8 nanoparticles, the surface area of the MZASA hydrogel is augmented, leading to an enhancement in dye adsorption capacity. In batch sorption mode, the maximum absorbency of the resulting hydrogel beads for methylene blue (MB) is 493.799 mg/g, which was a third greater than that of pure SA beads. Absorption of MB obeys the pseudo‐second‐order kinetic model and Langmuir isotherm model, suggesting monolayer chemisorption adsorption. Analysis of the thermodynamics proves that the entire adsorption process is exothermic and spontaneous. Moreover, the MZASA hydrogel beads show high selectivity for cationic dyes in the mixed dye test. Hence, the synthesized MZASA hydrogel beads serve as a highly effective, innovative, and reusable adsorbent for eliminating cationic dyes from water‐based solutions. [ABSTRACT FROM AUTHOR]

Carbon fiber (CF) has been extensively used in the research of microwave absorption owning to its excellent performance, but it also faces a series of problems such as impedance mismatch and low absorption intensity. The core‐sheath microstructure with CF as the inner core is constructed to solve the above issues by the introduction of other sheath layers. In this work, the MoS2 sheath and polyaniline (PANI) sheath are successively introduced into the CF matrix to obtain a hierarchical CF@MoS2@PANI nanocomposite with core‐sheath structure through a straightforward hydrothermal method and in‐situ polymerization. The obtained CF@MoS2@PANI nanocomposite exhibit the minimum reflection loss value of −42.23 dB at 10.11 GHz while the thickness is 2.5 mm, much higher than those of pure CF (below −10 dB) and CF@MoS2 nanocomposite (−25.60 dB). Moreover, the distinctive hierarchical core‐sheath structure contributes to providing more active sites, prolonging the transmission path of electromagnetic waves, and forming heterogeneous interfaces. Consequently, the electromagnetic wave attenuation mechanism of CF@MoS2@PANI nanocomposite is attributed to a synergistic effect of conductive loss, multiple reflection/scattering, dipole polarization, and interface polarization. This work offers an effective and promising strategy to design a three‐dimensional hierarchical core‐sheath microstructure for the development of composite absorbers. [ABSTRACT FROM AUTHOR]

When hydrogels are in environments with high water content, they usually undergo swelling, leading to a degradation of mechanical properties, which severely limits their application in underwater sensing. To solve this problem, we synthesized an anti-swelling, tough, double-crosslinked, dual-network hydrogel, P(AA-SMA)-CMC-Na, for underwater sensing. Due to the hydrophobic association and electrostatic interactions between the cationic surfactant N-Hexadecyltrimethylammonium chloride (CTAC) and poly (acrylate-methacrylate octadecyl ester) [P(AA-SMA)], as well as the dense network structure brought about by double cross-linking and the incorporation of CMC-Na, the hydrogel has excellent anti-swelling properties and mechanical properties (large stretchability of 955%, tensile strength of 252 kPa). Notably, after seven days of immersion in water (pH = 3, 5) and saline, stress and strain were elevated compared to the original hydrogel (strain up to 1460% and stress up to 805 kPa after immersion). The dynamic hydrophobic association of CTAC with SMA and the large number of hydrogen bonds within the hydrogel contributed to the excellent self-healing efficiency of the hydrogel (90%). The hydrogel was fabricated into a flexible strain sensor that showed keen sensitivity in the sensing range of 0–400% (GF values of 1.55, 2.87, and 5.03 for the ranges of 0–200%, 200–300% and 300–400%, respectively). It could accurately detect real-time signals of human movement in air, underwater, and seawater. Therefore, the P(AA-SMA)-CMC-Na hydrogel can meet the needs of underwater sensing and have great potential for applications in electronic skin, personal health detection, and flexible wearable electronics. [ABSTRACT FROM AUTHOR]