Hesham Tantawy

Electromagnetic interference (EMI) threatens the reliability of modern electronic systems, creating a demand for lightweight, absorption‐dominated shielding materials. In this work, multifunctional polyurethane (PU) foams reinforced with multi‐walled carbon nanotubes (MWCNTs) were fabricated via in situ polymerization and systematically evaluated in terms of microstructure, mechanical performance, electrical conductivity, and EMI shielding behavior. SEM analysis revealed a strong morphology–property correlation, where moderate MWCNT loading (1 wt%) refined the pore structure (average pore size ≈ 160 μm) and increased pore density, resulting in enhanced mechanical reinforcement (compressive modulus ≈ 4.1 MPa) and improved conductive pathways. EMI shielding measurements in the X‐band (8–12 GHz) demonstrated absorption‐dominated behavior, with the 1 wt% composite achieving an optimal total shielding effectiveness of approximately −16 dB. Although increasing the MWCNT content to 2 wt% further improved shielding effectiveness to −23 dB, it caused severe pore collapse and mechanical degradation due to nanotube agglomeration. Electromagnetic parameter analysis based on NRW‐derived relations confirmed strong dielectric losses and favorable impedance matching, explaining the effective attenuation achieved with only 6 mm thickness. Overall, this study establishes a structure–property optimization strategy for MWCNT/PU foams, highlighting their potential for lightweight EMI shielding applications.

In the quest for environmentally friendly materials with enhanced electromagnetic interference (EMI) shielding capabilities, carbon-based materials and metal–organic frameworks (MOFs) have shown significant promise. This study focuses on synthesizing a bimetallic ferromagnetic MOF [MIL-88B(Fe/Co)], in combination with graphene oxide (GO), to assess their EMI shielding performance as a composite. Controlled pyrolysis of the MOF/GO composites with varying GO content (15%, 20%, and 30%) led to partial decomposition of the MOF structure (P-Co-Fe-MOF) while preserving its crystallographic integrity and reducing GO to its reduced form (RGO). The resulting P-Co-Fe-MOF/RGO composites were evaluated at different loadings (0.5 g, 1 g, 1.5 g, and 2 g), with the P-Co-Fe-MOF/RGO30 composite exhibiting the highest EMI shielding efficiency. Based on these findings, a double-layer structure was designed, where the first layer was composed of the bimetallic MIL-88B(Fe/Co) framework. The second layer, consisting of pyrolyzed MOF combined with RGO, achieves a remarkable total shielding effectiveness (SE _T ) of 33 dB within the X-band range, attenuating nearly 99% of electromagnetic waves. This innovative double-layer structure demonstrates high shielding performance, offering a promising approach for developing effective EMI shielding materials.

The expanded graphite (EG) was used as a filler in EG/polyurethane (PU) composite foams for electromagnetic interference shielding (EMI). The EG/PU composite foams were characterized by Fourier transform infrared spectroscopy (FTIR) and SEM. The shielding effectiveness (SE) of the EG/PU composite form containing 5 wt% EG was −24 dB at 5 wt% in the 8–12 GHz range. The optimal EG loading was 3 wt% and the corresponding EG/PU composite foam had a total SE of −18.9 dB and fairly good mechanical characteristics (compressive strength: 13.43 MPa and compressive modulus: 4.95 MPa). These attributes position the EG/PU composite foam as a promising candidate for diverse EMI SE applications.Highlights: Synthesis by thermal exfoliation and characterization by x‐ray diffraction, Raman and SEM of EG. Preparation of EG/PU foams for enhanced EMI SE. Optimization of the EG loading with regard to SE and mechanical properties of the EG/PU foams.

Efficient electromagnetic waves absorbing materials while preserving structural integrity based on MIL-53(Fe)/reduced graphene oxide composites remains a challenging task. Most reported preparation techniques compromise structural integrity which limits its practical applications. This study reports innovative method by carefully controlling pyrolysis in a tubular furnace to produce Pyrolyzed MIL-53(Fe)/reduced graphene oxide (P-MIL-53(Fe)/RGO) composites to safeguard structural integrity while preserving RGO’s structure and achieving high EMI shielding efficiency. Various mass ratios of reduced graphene oxide were investigated (15%, 20%, and 30%) to indicate the impact of calcination in changing the degree of graphitization and its effect on the shielding performance. P-MIL-53(Fe)/RGO30 stands out, achieving notable total shielding effectiveness (SE_T) of 46.5 dB and absorption shielding efficiency (SE_A) of 40.3 dB with 2 g of reduced graphene oxide (5 mm thick). The study offers a simple strategy to produce the desired composite with preserved reduced graphene oxide’s structural integrity which has a potential EMI shielding performance. These insights hold promise for diverse applications demanding robust, high-performance electromagnetic wave shielding materials.