Wearable electromagnetic interference (EMI) shielding fabrics with excellent electromagnetic shielding performance, oxidation resistance, and structural stability are highly demanded for the rapid development of electronic devices and wireless communication. MXenes are metallic conductive materials with exceptional EMI shielding properties, but they are prone to oxidation in air and have poor structural stability and durability on fabric substrates. Herein, we present a one-step assembly method to fabricate fabrics coated with MXenes and polymeric sodium alginate (SA) composite (MXene-SA). SA protects MXenes from oxidation and forms a stable interlayer structure by bonding to MXenes. The MXene-SA coated fabrics are breathable and flexible, and have a low sheet resistance of 2.12 ± 0.08 Ω/sq and a high EMI shielding performance of 37.05 dB at X-band, which is comparable to the best 42.31 dB. Moreover, the MXene-SA coated fabrics exhibit high structural stability and oxidation resistance under various conditions of sonication disintegration, mechanical abuse, chemical corrosion, and humidity, compared to pure MXenes coated fabrics. We believe that the wearable and high-performance MXene-SA fabrics have great potential for the next generation of ultra-portable and wearable EMI shielding products.

In order to meet the requirements of the marine environment for microwave absorption (MA) materials, we put forward the strategy of constructing multi-functional composite materials, which integrate microwave absorption, anti-corrosion, and antibacterial properties. Herein, graphene oxide (GO) was used as a template to induce the growth of zeolitic imidazolate framework-8 (ZIF-8), simultaneously as a two-dimensional (2D) nanocontainers to load corrosion inhibitors to achieve pH-responsive and self-healing properties. Finally, quaternary ammonium salt (dimethyl octadecyl(3-trimethoxylsilyl propyl) ammonium chloride (DMAOP)) and sodium ascorbate (VCNa) were introduced to achieve synergistic antibacterial activity and the reduction of GO. The 2D strip-like structure of ZIF-8 was due to the confined growth induced by the electrostatic attraction between ZIF-8 and GO sheets. The as-obtained reduced GO (RGO)/ZIF-8/DMAOP₅ exhibited excellent microwave absorption (MA) properties, with a minimum reflection loss (RL) value of −47.08 dB at 12.73 GHz when the thickness was 2.8 mm. Moreover, the effective absorption bandwidth reached 6.84 GHz. After soaking in 3.5% NaCl solution for 35 days, the RGO/ZIF-8/DMAOP₅-0.7% coating still achieved an impedance value of 4.585 × 10⁷ Ω·cm² and a protective efficiency of 99.994%, providing superior anti-corrosion properties. In addition, fantastic antibacterial activity was obtained, with the antibacterial rates of RGO/ZIF-8/DMAOP₁₀ reaching 99.39% and 100% against Escherichia coli and Staphylococcus aureus. This work could open new avenues towards the development of a new generation of multifunctional MA materials.

Although graphene aerogels (GA) have been attracted great attention, the easy-operation and large-scale production of GA are still challenges. Further, most GA have a monolith-like appearance, limiting their application-specific needs. Herein, we highlight graphene aerogel spheres with controllable hollow structures (HGAS) that are delicately designed and manufactured via coaxial electrospinning coupled with freeze-drying and calcination. The HGAS exhibit a spherical configuration at the macroscale, while the construction elements of graphene on the microscale showing an interconnected radial microchannel structure. Further, ball-in-ball graphene aerogel spheres (BGAS) are obtained by reference to the triaxial electrospinning technology. The as-prepared spheres possess the controllable integrated conductive networks, leading to the effective dielectric loss and impedance matching, thus bringing on high-performance microwave absorption. The as-obtained HGAS shows a minimum reflection loss of -52.7 dB, and a broad effective absorption bandwidth (f_E) of 7.0 GHz with thickness of 2.3 mm. Further, the f_E reaches 9.3 GHz for BGAS with thickness of 3.4 mm. Aforementioned superior microwave absorption of HGAS and BGAS confirms combination of multiaxial electrospinning and freeze-drying on the multiscale is an effective strategy for scalable fabrication of advanced microwave absorbing functional graphene aerogel spheres.

Recently, biomass-derived three-dimensional (3D) porous carbon materials have been gaining more interest as promising microwave absorbers due to their low cost, vast availability, and sustainability. Here, a novel 3D interconnected porous magnetic carbon foams are in-situ synthesized via a combination of sol-gel and carbonization process with wheat straw as the carbon source and FeCl₃·6H₂O as the magnetic regulating agent. During the process of foams formation, the lignocelluloses from the steam-exploded wheat straw are converted into interconnected carbon sheet networks with hierarchical porous structures, and the precursor FeCl₃·6H₂O is converted into magnetic nanoparticles uniformly embedded in the porous carbon foams. The generated magnetic nanoparticles are benefit to enhance the interface polarization and magnetic loss ability to improve the efficient complementarities between the dielectric and magnetic loss, thus increasing the impedance matching. The obtained sample treated at 600 ℃ displays the best microwave absorption (MA) performance. It presents a minimal reflection loss (RL) of −43.6 dB at 7.1 GHz and the effective bandwidth (RL < −10 dB) is 3.3 GHz with the thickness of 4.7 mm. The 3D porous structure, multi-interfaces and the synergy of dielectric loss and magnetic loss make great contribution to the outstanding MA performance.