Magnetic Bimetallic Heterointerface Nanomissiles with Enhanced Microwave Absorption for Microwave Thermal/Dynamics Therapy of Breast Cancer

Microwave thermotherapy (MWT) has shown great potential in cancer treatment due to its deep tissue penetration and minimally invasive nature. However, the poor microwave absorption (MA) properties of the microwave thermal sensitizer in the medical frequency band significantly limit the thermal effect of MWT and then weaken the therapeutic efficacy. In this paper, a Ni-based multilayer heterointerface nanomissile of MOFs-Ni-Ru@COFs (MNRC) with improved MA performance in the desired frequency band via introducing magnetic loss and dielectric loss is developed for MWT-based treatment. The loading of the Ni nanoparticle in MNRC mediates the magnetic loss, introducing the MA in the medical frequency band. The heterointerface formed in the MNRC by nanoengineering induces significant interfacial polarization, increasing the dielectric loss and then enhancing the generated MA performance. Moreover, MNRC with the strong MA performance in the desired frequency range not only enhances the MW thermal effect of MWT but also facilitates the electron and energy transfer, generating reactive oxygen species (ROS) at tumor sites to mediate microwave dynamic therapy (MDT). The strategy of strengthening the MA performance of the sensitizer in the medical frequency band to improve MWT-MDT provides a direction for expanding the clinical application of MWT in tumor treatment.

Lightweight and Hydrophobic Three-Dimensional Wood-Derived Anisotropic Magnetic Porous Carbon for Highly Efficient Electromagnetic Interference Shielding

Constructing multifunctional characteristics toward advanced electromagnetic interference shielding materials in harsh environments has become a development trend. Herein, the wood-derived magnetic porous carbon composites with a highly ordered anisotropic porous architecture were successfully fabricated through a pyrolysis procedure. The three-dimensional porous skeleton inherited from the wood stock serves as an electrically conductive network and incorporates magnetic Ni nanoparticles homogeneously and firmly embedded within the carbon matrix that can further improve the electromagnetic attenuation capacity. The optimized Ni/porous carbon (PC) composite exhibits an exceptional electromagnetic interference (EMI) shielding effectiveness of 50.8 dB at the whole X band (8.2-12.4 GHz) with a low thickness (2 mm) and an ultralow density (0.288 g/cm³) and simultaneously possesses an extraordinary compressive strength (11.7 MPa) and a hydrophobic water contact angle (152.1°). Our study provides an alternative strategy to utilize green wood-based materials to design multifunctional EMI shielding composites.

Lightweight carbon-red mud hybrid foam toward fire-resistant and efficient shield against electromagnetic interference

Lightweight, porous, high-performance electromagnetic interference (EMI) shielding and fire-resistant materials are highly demanded in aerospace and defense applications. Due to the lightweight, open porosity and high surface area, carbon foam has been considered as one of the most promising candidates for EMI shielding applications. In the present investigation, we demonstrate the development of novel carbon-red mud hybrid foams with excellent EMI shielding effectiveness (SE). The carbon-red mud hybrid foams are prepared using phenolic resin as a carbon source and red mud (industrial waste) as filler. We observed that the inclusion of red mud in carbon-red mud hybrid foams significantly enhances their dielectric, magnetic, EMI shielding and thermal properties. The EMI shielding results show that absorption is the main contributor to the total EMI SE. The maximum total EMI shielding effectiveness is achieved to be 51.4 dB in the frequency range of 8.2–12.4 GHz for carbon-red mud hybrid foam having 20 wt. % of red mud. The CF-RM20 also showed excellent fire resistance and high thermal stability at elevated temperatures.

GO@Fe3O4@CuSilicate Composite with a Hierarchical Structure: Fabrication, Microstructure, and Highly Electromagnetic Shielding Performance

Two nanocomposites with a hierarchical structure (GO@CuSilicate@Fe₃O₄ and GO@Fe₃O₄@CuSilicate) were fabricated in this paper. These as-synthesized nanocomposites were analyzed for their structural, compositional, and morphological features by X-ray diffraction, scanning electron microscopy (SEM), Raman spectroscopy, and Brunauer-Emmett-Teller methods. SEM images showed that both nanocomposites had a core-shell structure, and their shells were composed of CuSilicate nanoneedle arrays. Further, their total electromagnetic shielding efficiency was measured and compared in a wide frequency range of 8-12 GHz (X-band). Because of the "antenna" role of CuSilicate nanoneedle arrays and the polarization at the interface between graphene oxide (GO) and Fe₃O₄, GO@Fe₃O₄@CuSilicate showed higher electromagnetic shielding performance than that of GO@CuSilicate@Fe₃O₄. With 1 mm thickness, GO@Fe₃O₄@CuSilicate showed a high electromagnetic shielding efficiency (over 40 dB) in the whole X-band (8.2-12.4 GHz) and reached a maximum value (41.8 dB) at 8.2 GHz. Its total electromagnetic shielding efficiency was mainly contributed by absorption rather than reflection. This study provided an idea for the structural design of high-performance electromagnetic shielding materials in the GHz frequency range (X band).

Light-weight and low-cost electromagnetic wave absorbers with high performances based on biomass-derived reduced graphene oxides

Rational structure design of microwave absorption material is extremely significant from the perspectives of enhancing the electromagnetic microwave absorption (EMA) performance and adapting to cost-effective and sustainable industrial applications. Here, reduced graphene oxides (rGOs) with curl structures derived from corn stover are applied for the absorption of electromagnetic waves. The results suggest that biomass-rGO show the maximum reflection loss of -51.7 dB and an effective absorption bandwidth 13.5 GHz (4.5-18 GHz) at a thickness of 3.25 mm, implying the unique critical role of the microstructure in adjusting the EMA performance. Moreover, the successful conversion of waste biomass into widely used electromagnetic wave absorbing materials could solve the problems of environmental pollution caused by straw burning.

Comparison of Experimental and Modeled EMI Shielding Properties of Periodic Porous xGNP/PLA Composites

Microwave absorbing materials, particularly ones that can achieve high electromagnetic interference (EMI) absorption while minimizing weight and thickness are in high demand for many applications. Herein we present an approach that relies on the introduction of periodically placed air-filled pores into polymer composites in order to reduce material requirements and maximize microwave absorption. In this study, graphene nano platelet (xGNP)/poly-lactic acid (PLA) composites with different aspect ratio fillers were characterized and their complex electromagnetic properties were extracted. Using these materials, we fabricated non-perfect electrical conductor (PEC) backed, porous composites and explored the effect of filler aspect ratio and pore geometry on EMI shielding properties. Furthermore, we developed and experimentally verified a computational model that allows for rigorous, high-throughput optimization of absorbers with periodic porous geometries. Finally, we extend the modeling approach to explore the effect of pore addition on PEC-backed composites. Our composite structures demonstrated decreased fractions of reflected power and increased fractions of absorbed power over the majority of the X Band due to the addition of periodically arranged cylindrical pores. Furthermore, we showed that for xGNP/PLA composite material, reflection loss can be increased by as much as 13 dB through the addition of spherical pores. The ability to adjust shielding properties through the fabrication of polymer composites with periodically arranged pores opens new strategies for the modeling and development of new microwave absorption materials.

Double network nested foam composites with tunable electromagnetic wave absorption performances

A double network nested SiC_nw/CF foam composite was fabricated with outstanding absorbing properties.

Electromagnetic and microwave absorption characteristics of PMMA composites filled with a nanoporous resorcinol formaldehyde based carbon aerogel

Nanostructured carbons have opened up new perspectives in fields of electromagnetic (EM) applications. The present study aims at the processing of microwave absorbing (MA) materials based on carbon aerogels (CAs) in polymethyl methacrylate (PMMA) matrix to be used in X-band frequency. CAs were synthesized by carbonization of a sol–gel derived organic gel from resorcinol and formaldehyde as starting materials. Microwave attenuation properties of the prepared composites were investigated in terms of CAs particle size distribution (PSD) and mass fraction. To do so, the optimal PSD was initially determined by assessing the EM attenuation performance of the CAs/PMMA composites with constant mass loading (10 wt%) and differing particle sizes. Next, the EM properties of the selected CAs with the optimal particle size was measured as a function of mass fraction varying from 1 to 15 wt% in order to obtain a highly efficient CAs based MA. The results indicate that the dielectric loss of CAs composites can be enhanced by optimizing the PSD as well as the mass fraction of CAs. The effective absorption bandwidth of composites containing 10 wt% of CAs exceeded 3.7 GHz at a very thin thickness of 1.9 mm indicating that these materials present advantages as microwave absorbers.

Both PSD and filler content play dominant role in tuning EM absorption performance of CAs composites.

Microwave absorbing property optimization of starlike ZnO/reduced graphene oxide doped by ZnO nanocrystal composites

The microwave absorption properties of a nanocomposite containing star-like ZnO and reduced graphene oxide doped by ZnO nanocrystals are optimized.

Phthalonitrile-Based Carbon Foam with High Specific Mechanical Strength and Superior Electromagnetic Interference Shielding Performance

Electromagnetic interference (EMI) performance materials are urgently needed to relieve the increasing stress over electromagnetic pollution problems arising from the growing demand for electronic and electrical devices. In this work, a novel ultralight (0.15 g/cm(3)) carbon foam was prepared by direct carbonization of phthalonitrile (PN)-based polymer foam aiming to simultaneously achieve high EMI shielding effectiveness (SE) and deliver effective weight reduction without detrimental reduction of the mechanical properties. The carbon foam prepared by this method had specific compressive strength of ∼6.0 MPa·cm(3)/g. High EMI SE of ∼51.2 dB was achieved, contributed by its intrinsic nitrogen-containing structure (3.3 wt% of nitrogen atoms). The primary EMI shielding mechanism of such carbon foam was determined to be absorption. Moreover, the carbon foams showed excellent specific EMI SE of 341.1 dB·cm(3)/g, which was at least 2 times higher than most of the reported material. The remarkable EMI shielding performance combined with high specific compressive strength indicated that the carbon foam could be considered as a low-density and high-performance EMI shielding material for use in areas where mechanical integrity is desired.

Novel 3D lightweight carbon foam as an effective adsorbent for arsenic(v) removal from contaminated water

An efficient removal of pentavalent arsenic (As(v)) from water has been developed using novel three-dimensional (3D) light weight carbon foam which exhibit adoption capacity of 38.4 μg g⁻¹.

Three-dimensional and highly ordered porous carbon–MnO2 composite foam for excellent electromagnetic interference shielding efficiency

The combination with MnO₂ nanoparticles in carbon matrix, the carbon foam exhibit absorption dominating specific EMI shielding value of −150 dB cm³ g⁻¹ with high strength of 7.8 MPa.

Mesocarbon microsphere composites with Fe3O4 nanoparticles for outstanding electromagnetic interference shielding effectiveness

In situ, development of mesocarbon microsphere (MCMS) composites with magnetic Fe₃O₄ nanoparticles for outstanding electromagnetic (EMI) shielding effectiveness.

A carbon fiber based three-phase heterostructure composite CF/Co0.2Fe2.8O4/PANI as an efficient electromagnetic wave absorber in the Ku band

The synthesized three-phase heterostructure composite CF/Co_0.2Fe_2.8O₄/PANI shows an excellent EM wave attenuation performance in the K_u band and the minimum RL values are all lower than −20 dB with an absorber thickness of 3.1–4.1 mm.

Polymer nanocomposite foam filled with carbon nanomaterials as an efficient electromagnetic interference shielding material

Among different carbon nanomaterial foam-filled polymer composites, graphene-based foam gives superior specific shielding effectiveness when compared to typical metals.

ZnS nanowall coated Ni composites: facile preparation and enhanced electromagnetic wave absorption

The microwave absorption properties of ultrathin ZnS wall-coated Ni composites were superior to those of Ni microspheres and ZnS particles.