Lightweight Composite Aramid Nanofiber Aerogel With Multistage Pores and Layered Structure for Acoustic and Thermal Insulation

Aerogels are currently advanced multifunctional sound-absorbing materials. Aramid nanofiber aerogels (ANFs) also possess lightweight and excellent thermal insulation properties, making them high-performance materials for extreme environments with broad application prospects. In this study, aramid fibers were used as raw materials, which were uniformly mixed with surfactants and cross-linkers, followed by ultrasonic pulverization treatment to fabricate multilayered porous hierarchical composite aramid nanofiber aerogels (MPL-ANFs). The results show that MPL-ANFs not only retain the lightweight and excellent thermal insulation properties of ANFs but also form a hierarchical porous structure that effectively absorbs sound. Specifically, MPL-ANFs with a surfactant-to-aramid fiber weight ratio of 1:1 exhibit excellent acoustic properties, with a noise reduction coefficient of 0.52 and an average sound absorption coefficient of 0.71. MPL-ANFs also demonstrate flame retardant and superior thermal insulation properties, with a thermal conductivity of 0.0368 W/(m*K). After heating on a 120 degrees C heat plate, the sound absorption performance of the aerogel remains largely unchanged. This work significantly enhances the potential of ANFs as novel acoustic materials, broadening their application prospects.