Thermo‐Acoustic‐Mechanical Coupling in Polyarylate Nanofiber‐Built Aerogel Honeycombs Driven by Skeleton Blocking and Core Dissipation

In complex environments like aerospace cabins and high‐speed rail transit, structural materials must balance high specific strength, noise suppression, thermal management, and electromagnetic compatibility. To overcome the limitations of commercial aramid honeycombs under thermo‐acoustic‐mechanical coupling, this study develops a nanocomposite aerogel honeycomb using thermotropic liquid crystal polyarylate nanofibers (PAR NFs) and SiO 2 hollow microspheres (SiO 2 HMs). Fabricated via in situ thermal welding and freeze‐drying, the composite enhances load transfer, anti‐buckling capacity, and phonon/sound wave control through interfacial scattering and impedance gradients. The core PAR aerogel, with an extensive porous network, suppresses both gas‐ and solid‐phase heat conduction, achieving broadband sound absorption via the Knudsen effect, multi‐level scattering, and viscous dissipation. The composite exhibits superior compressive strength (114 MPa), Young's modulus (411 MPa), toughness (51 MJ/m 3 ), and thermal conductivity (0.0538 W m −1 K −1 ), with an average sound absorption coefficient of 0.484, outperforming commercial foams. Additionally, it demonstrates excellent electromagnetic transparency and recyclability, making it a promising multifunctional material.