A synergistic strategy for fabricating a highly flexible poly(m-phenylene isophthalamide) nanofiber-reinforced polyimide aerogel for high-temperature filtration

Particulate matter (PM) has a significant impact on air quality, especially the PM produced by automobile exhaust and high temperature environment. Therefore, it is of great significance to develop a technology that can effectively intercept fine PM under high temperature conditions. This study reports the construction of poly(m-phenylene isophthalamide) (PMIA) nanofiber-reinforced polyimide aerogel (PPNFAs) filters using freeze-drying and electrospinning for high temperature filtration. After 100 compression cycles, the maximum compressive stress of PPNFAs is reduced by only 15%. When the content of PMIA is 0.65 wt%, PPNFAs has a high porosity (97.35%), high specific surface area (8.87 m 2 g −1 ) and highest dust holding capacity (124.8 m 2 g −1 ). After 15 days of continuous heating test at 300°C, the filtration efficiency of PPNFAs filter for different diameter particles of impurities remained above 98%. Therefore, the PPNFAs filter prepared in this study provides a new design concept for a new generation of high temperature filters.