In-situ construction of phase-separated interconnected PVA@RGO frameworks using dual-crosslinking/reduction steps for broadband microwave absorption and enhanced structural performance of aramid honeycombs

Achieving broad effective absorption bandwidth (EAB) with minimal weight gain in aramid honeycomb (HC) remains a significant challenge. This study successfully prepared crosslinked PVA/RGO foam in situ-filled aramid HC composites using freeze-drying and low-temperature chemical reduction processes. By adjusting the GO content, partial to complete encapsulation of the PVA framework by RGO sheets could be achieved, and all samples exhibited a dense framework network structure as seen in the SEM. The [email protected]/0.4Vc foam filled HC achieves a broadband EAB of 12.74 GHz at a thickness of 30 mm. Such foam samples can also achieve effective absorption at 1.19–2 GHz. The foam filled honeycomb further increases the compressive strength to 5.24 MPa compared with pure HC. Obvious overlap between the CST electric field distribution demonstrates that the conductive loss and λ/4 interference cancels are the main pathways of MA. Overall, the PVA/RGO foam-filled HC composites exhibit ultra-broadband microwave absorption performance with enhanced structural compressive strength, which has significant feasibility and application value in aerospace stealth structures.