3D bimodal-structured polysulfonamide fibrous aerogel with integrated high-temperature PMs filtration and thermal insulation properties.

Particulate matters (PMs) emitted from high-temperature industrial processes, especially ultrafine particles (PM0.3), pose severe threats to human health and the environment. Developing filtration materials that simultaneously combine high efficiency, low resistance, and thermal stability under harsh conditions remains challenging. In this study, a polysulfonamide (PSA)-based fibrous aerogel with a bimodal fiber architecture and a porous three-dimensional (3D) curly fiber network was fabricated by co-electrospinning. The aerogel consists of a thermally stable composite coarse fibers composed of PSA, polyacrylonitrile (PAN), and SiO2 nanoparticles, interpenetrated with pure PSA fine fibers, resulting in a highly porous structure with porosity above 98%. The formation of the lightweight 3D architecture was attributed to the synergistic effects of moisture-induced phase separation, enhanced jet whipping and fiber curl generation arising from the mechanical mismatch between polymer components. The resulting 3D fibrous aerogel delivered a PM0.3 filtration efficiency of 98.5% with a low pressure drop of ∼84 Pa. Even after exposure to 250°C for 12 h, it retained a PM0.3 filtration efficiency of 92.31% and a stable pressure drop of 73 Pa. The fibrous aerogel also exhibits excellent resistance to acid and alkali corrosion. Moreover, its highly porous structure and 3D architecture provided excellent thermal insulation, enabling simultaneous high-temperature PMs filtration and thermal protection. Computational fluid dynamics (CFD) simulations further demonstrated that the optimized pore geometry and fiber arrangement enhanced airflow distribution and particle interception. This study offers an effective strategy for designing lightweight, thermally robust fibrous aerogels for high-temperature filtration and thermal management applications.