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 multifunctionality. 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 T3C2Tx 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 T3C2Tx 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.