Novel multi-hierarchical nanofiber aerogel for high efficient filtration of high-temperature flue gas

Fibrous air filtration materials are highly effective at capturing particulate matter (PM) from emissions. Yet, many commercially available filters are difficult to achieve high filtration efficiency for PM while maintaining low filtration resistance. Furthermore, the elevated temperatures (ranging from 100.0-250.0 °C) commonly associated with pollution sources necessitate stringent thermal resistance requirements for filtration materials. Here, a new strategy for the preparation of aerogels for high-temperature gas filtration is reported. Firstly, a unique "grooved and secondary pore" structure polyaryl thioether sulfone (GPASS) nanofibers are initially fabricated using a combination of "wet" electrostatic spinning and aqueous etching. And then, the oxidized GPPASS aerogel (O-GPPASS) can be obtained through simple acid and freeze-dried treatment. It is found that the as-prepared aerogel exhibits high filtration efficiency of 99.7 % for PM0.3, accompanied by low pressure drop of 17.2 Pa, and high quality factor (QF) of 0.362 Pa−1. Remarkably, after enduring high-temperature conditions of 330.0 °C for 4.0 h, the O-GPPASS aerogel still maintains an impressive filtration performance, with a 99.6 % efficiency and a pressure drop of 17.6 Pa for PM0.3 particles. It will well meet the needs of filter materials used in high temperature environments. This innovation is poised to supersede traditional high-temperature air filtration materials, paving the way for sustainable advancements in industrial applications.