Loofah-Inspired Hierarchically Porous Fibrous Aerogels with Flame-Retardant Properties for Efficient Low-Frequency Noise Reduction

The incessant activities of urban populations in high-density environments continuously generate noise pollution, which significantly impairs daily living conditions. Conventional fibrous sound-absorbing materials frequently encounter challenges in simultaneously achieving low-frequency acoustic absorption, lightweight characteristics, and flame retardancy. Inspired by the porous structure of natural loofah, an innovative dual-polymer interfacial separation pore-forming strategy was developed. This strategy enables the one-step fabrication of hierarchically porous fibrous aerogels via electrospinning. The resulting fibrous aerogels, with a thickness of 2 cm, exhibit notable acoustic absorption performance, achieving a noise reduction coefficient of 0.55 at an ultralow density of 15 mg·cm–3, along with a peak sound-absorption coefficient of 0.976 at 1000 Hz. Through the strategic incorporation of expanded graphite sheets, the aerogels also demonstrated excellent flame retardancy. This structural design shows considerable potential for noise reduction applications and provides an approach for preparing multifunctional acoustic materials.