Aerogels enable multifunctionality in GFRP composites: enhanced mechanical properties, thermal conductivity, and electromagnetic microwave absorption

To meet the stringent requirements of next-generation aerospace, electronics, and environmental applications, structural materials must possess intrinsic multi-functionality. However, conventional glass fiber/epoxy (GF/EP) composites, while structurally competent, are hindered by deficiencies such as poor interlaminar toughness, low thermal conductivity, and an inability to interact effectively with electromagnetic microwaves. In this study, we transform GF/EP composites from traditional structural components into advanced structural multifunctional materials by embedding T₃C₂T_x MXene/poly(acrylic acid) (PAA) aerogels (TPA) as integral interlayers. Hybrid composites with tailored architectures, the aligned (GFAM_A) and the random (GFAM_R) TPA/GF/EP laminates, were fabricated using unidirectional and isotropic freeze-casting, respectively. The resulting hybrid composites show significant improvements over baseline GF/EP. The integrated aerogel phase promotes mechanisms of crack deflection and distributed energy dissipation, leading to notable enhancements in interlaminar shear strength (ILSS) and fracture toughness. Critically, the continuous T₃C₂T_x MXene network within the aerogel creates efficient through-thickness thermal conduction pathways and imparts strong microwave absorption properties to the previously electromagnetically transparent composite. Notably, the configuration incorporating aligned aerogels achieves simultaneous increases of approximately 52% in ILSS, 78% in toughness, and 42% in thermal conductivity, along with effective microwave absorption properties, exhibiting a minimum reflection loss of −23.47 dB and a maximum effective bandwidth of 2.70 GHz. This study demonstrates that precision aerogel engineering provides a powerful strategy for upgrading conventional glass fiber composites into advanced multifunctional structural materials. (Figure presented.).