This study investigates the microwave-assisted catalytic pyrolysis of polyetherimide (PEI). Activated carbon (AC), petroleum coke, graphite, silicon carbide, and AC-supported oxides (Fe₃O₄, Fe₂O₃, Al₂O₃, and ZnO) were chosen as microwave absorbers and/or catalysts to determine the impact of microwave absorber/catalyst type on the decomposition. Experiments were conducted at a microwave power of 400 W, which corresponded to an average bulk temperature of 400 °C, for 10 min in an argon atmosphere. No PEI remained intact after the treatments and the products were in the gas, liquid, wax, and solid phases, with the gas phase being the dominant fraction. Decomposition with the AC–Fe₃O₄ catalyst resulted in the highest gas yield and hydrogen production of up to 20 mmol g⁻¹ PEI, corresponding to 76% of the hydrogen content of PEI. Decomposition without metal oxides produced more wax, whereas metal oxides shifted the product distribution toward gases and/or aromatic condensates (notably toluene), depending on the oxide. The catalysts were deactivated by carbon deposition, degradation of the carbon support and/or reduction of metal oxide species. These results demonstrate that microwave-assisted catalytic pyrolysis of PEI enables hydrogen generation and the recovery of aromatic hydrocarbons (e.g., toluene, styrene, and naphthalene), highlighting its potential as a chemical recycling route for high-performance thermoplastics. • Microwave-assisted PEI decomposition achieved complete polymer conversion. • AC–Fe₃O₄ combined microwave absorption with high H₂ yield from PEI. • Catalyst choice controlled H₂ and aromatic recovery from PEI decomposition.

Microwave absorption and mechanical properties of integrated glass-carbon hybrid composites: Co-design of weaving mode and frequency-selective surface for X-band applications

Robust and thermostable silicon-based aerogels towards highly efficient thermal insulation and microwave absorption

Colloidal particle shape matters: Emulsion-directed shape design, interfacial mechanisms, and applications.

A“Waste-to-Resource” strategy for fabricating efficient ceramic-based composite microwave absorbers

PI/BaF12O19/CS/MWCNTs coating with porous PI-walled encapsulation structure enables thickness-insensitive and robust microwave absorption

Microwave absorption performance of an ultra-thin carbon composite absorber CuFe2O4/Cu/Fe4N/Fe3O4/C

Preparation of a flexible SCF for ultra-high bandwidth-to-thickness ratio microwave absorption in the C-band

Flexible and transparent SiO2-ITO composite films for microwave absorption by magnetron co-sputtering

Bimetallic MOF-derived CoZn-C/MWCNTs composite for lightweight and wideband microwave absorption

Synergistic molecular assembly and impedance matching in polyimide-derived porous carbon nanosheets for advanced microwave absorption

Spectrum-to-thermo defense: Te-Ni S6@Diatomite hierarchical networks simultaneously mastering microwave absorption, corrosion resistance, antibacterial activity, and thermal insulation

Facile synthesis of carbon spheres with isomeric heterogeneous interfaces for efficient microwave absorption

Controllable preparation of 3D porous Co/Mo2C/C aerogels: Synergizing multifunctionality with efficient microwave absorption performance

The rapid advances in detection technologies have raised greater demands on microwave-steady materials, particularly for curved surfaces and movable components of aircraft that are highly susceptible to detection. However, electromagnetic wave (EMW) absorbers based on composite metastructures or metal-backed resonant cavities often suffer from intrinsic rigidity, resulting in poor conformability to complex surfaces and consequently compromised microwave-absorption performance. Herein, inspired by the locally segmented deformability of soft-bodied organisms, a deformation-adaptive EGaIn/CIP-TPU nanofibrous absorber is developed through liquid-metal confinement within electrospun nanofibers, which integrates segmented fiber network reconfiguration with EGaIn/CIP-induced dielectric-magnetic synergistic attenuation for flexible microwave absorption. Specifically, the flexible microwave absorber delivers a minimum reflection loss (RL) of -51.4 dB at a matching thickness of 2.2 mm. Meanwhile, these absorbers exhibit elastic recovery ratios above 70% and show stable mechanical responses over 500 compression cycles. This study demonstrates an effective balance between mechanical adaptability and microwave-absorption performance, providing a promising strategy for next-generation flexible EMWA.

The high-efficiency absorption of low-frequency electromagnetic waves remains a key bottleneck in electromagnetic protection. Conventional carbon/magnetic fillers are limited by excessively large skin depth, limited magnetic response, and oxidation-induced parameter drift at elevated temperatures, making it difficult to simultaneously satisfy low-frequency absorption and high-temperature durability. This work proposes a charge imbalance-driven Jahn-Teller strategy and fabricates single-phase La1-xCaxMnO3 perovskites via a sol-gel method. The Ca2+/La3+ ionic-size mismatch induces MnO6 octahedral distortion and is accompanied by Mn3+/Mn4+ redistribution and oxygen-vacancy evolution, which strengthens polarization-related dielectric loss and enables coordinated improvement in attenuation capability and impedance matching. Consequently, the dominant dielectric relaxation/absorption response is shifted toward lower frequencies. The optimized sample achieves a minimum reflection loss of -40.46 dB at 4.72 GHz with an effective absorption bandwidth of 4.40 GHz. Far-field radar cross-section simulations further provide evidence of scattering suppression, with a maximum echo reduction of 30.7 dB·m2 for a metal plate. This strategy is extendable to perovskite oxide systems and offers a generalizable design guideline for thermally robust low-frequency absorbing coatings.

Manganese residue is a dangerous industrial by-product and has traditionally been stored. Conventional harmless treatment can stabilize Mn2+, but its resource utilization is relatively difficult due to the complex composition of manganese residue. This study proposes a sustainable development approach for synthesizing high-performance M-type ferrite BaFe11.6Mn0.4O19 from manganese residue rich in Fe and Mn for microwave absorption. By optimizing roasting conditions, we controlled oxygen vacancy concentration, enhancing the ferrite's dielectric and magnetic properties for superior microwave absorption. By simulating the composition of rare earth solid waste, rare earth elements La2O3 and CeO2 were incorporated into ferrite. Further optimize the loss matching mechanism and shielding effect. Characterization techniques confirmed a multiphase-phase M-type ferrite structure with a minimum reflection loss of -33.42 dB. It is clarified that the main reason for the performance improvement mechanism after the incorporation of rare earths is that the formation of new phases and the appearance of solid solutions promote the synergistic effect in polarization and electromagnetic energy dissipation. This method provides a scalable model for industrial waste recycling. This method provides a scalable model for industrial waste recycling.

Combing untrabroadband electromagnetic wave absorption with efficient de-icing is critical in aerospace applications. However, synergistically integrating these two functions poses a significant challenge. A critical barrier lies in the opposing requirements that achieving efficient electrothermal heating demands high electrical conductivity, which is often counterproductive to the impedance matching needed for effective electromagnetic wave (EMW) absorption. Herein, we report a bionic mandala-like heterostructure designed to overcome this compatibility challenge. This architecture is constructed from MOF-derived NiCo2O4/CoO@C composites, which create hierarchical conductive networks. The biomimetic mandala heterostructure simultaneously promotes multi-dimensional EMW scattering for absorption and enables efficient Joule heating for de-icing. The resulting multilayer metastructure achieves full-band effective microwave absorption (RL < -10dB) across the entire 2-18GHz range, which overcame the compatibility contradiction between broadband electromagnetic wave absorption and electrothermal deicing. Notably, it delivers a record-breaking strong absorption bandwidth (RL < -20dB) of 6.36GHz, outperforming all reported materials to date, alongside excellent broadband terahertz absorption performance. Furthermore, the surface material of multilayer absorber structure exhibits a rapid electrothermal response under a low driving voltage. This work provides a biomimetic structural design strategy for multifunctional materials that concurrently address broadband electromagnetic protection and active thermal management.

Extra-heavy oil is an important strategic energy resource, but its ultra-high viscosity severely limits efficient production. Conventional thermal recovery and chemical flooding are often associated with high energy consumption, environmental concerns, and limited reservoir adaptability. In this study, an intelligent responsive magnetic Janus nanocatalyst (IRMJN) was developed and coupled with microwave irradiation to enable low-energy and controllable in situ upgrading and oil mobilization. IRMJN features a spatially separated multifunctional architecture, in which Fe₃O₄ serves as the magnetic core for rapid recovery, MoS₂ nanosheets are selectively anchored on one side as catalytic active sites, and graphene quantum dots enhance microwave absorption to generate a synergistic nanoscale hotspot effect. Long-chain alkyl groups grafted onto the magnetic side further impart interfacial orientation capability. Under optimized conditions, the IRMJN-microwave system reduced the viscosity of extra-heavy oil by more than 95% at a bulk temperature of 100°C, clearly outperforming microwave treatment alone and conventional catalytic systems. Core flooding tests showed an additional oil recovery of more than 18.5% after water flooding. The catalyst also exhibited excellent magnetic recoverability and cycling stability. These results provide a promising strategy for the green and efficient development of extra-heavy oil resources.

Developing multifunctional materials that integrate microwave absorption, thermal insulation, ultralow density, and load-bearing capabilities is crucial for applications in complex environments. Herein, hydrogenated titanium dioxide nanofibrous sponges (H-TiO2 NFSs) featuring oxygen vacancies and heterogeneous interfaces were fabricated simply via electrospinning, followed by calcination and plasma treatment. The hydrogenation process modulated the band structure and introduced interfacial polarization, effectively enhancing the electromagnetic wave (EMW) attenuation performance. Consequently, the synthesized ceramic sponges exhibited a minimum reflection loss (RLmin) of -55.95 dB at 4.4 mm, with an effective absorption bandwidth of 4.2 GHz covering the X-band. Furthermore, the three-dimensional interconnected nanofibrous architecture endowed the H-TiO2 NFSs with ultralow density (0.047 g/cm3), low thermal conductivity (0.0356 W·m-1·K-1), and stable compressive resilience, including a residual strain of less than 18% after 100 cycles at 50% strain for H-TiO2-150 W. The as-obtained defect-engineered H-TiO2 NFSs are competitive candidates for thermal insulation and highly efficient X-band microwave absorption in harsh thermomechanical environments.