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

Abstract

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 SiO₂ hollow microspheres (SiO₂ 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/m³), 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.