One-step electrospinning of PVDF/PSU porous fibrous sponges with enhanced low-frequency sound absorption

Owing to their exceptional sound absorption performance, fiber materials have been extensively employed in the architecture and transportation sectors. However, their relatively large fiber diameter results in a diminished specific surface area, which consequently hinders further enhancement of their acoustic absorption capabilities. Herein, we fabricate fluffy PVDF/PSU fibrous sponges via one-step electrospinning by optimizing blending ratios to achieve microfiber (4 μm) with interconnected hierarchical pores and high specific surface area. Optimal PVDF/PSU composites produced bicontinuous porous fibers with exceptional specific surface area (specific surface area =20.58 m²·g−1 ) and structural fluffiness. Sound absorption tests revealed a noise reduction coefficient (NRC) of 0.49, notably surpassing commercial sound-absorbing materials, with a peak absorption efficiency of 0.923 at 1000 Hz, demonstrating exceptional low-frequency sound absorption performance. The porous fibrous sponges feature an ultra-low bulk density of 4.36 mg·cm−³, a substantial water contact angle of 130°, and a tensile breaking strength of 23.78 kPa, fully satisfying practical application prerequisites.