High-Temperature-Resistant Dual-Scale Ceramic Nanofiber Films toward Improved Air Filtration

Currently, air pollution primarily arises from industrial emissions, coal combustion, and automobile exhaust, posing significant challenges for mitigation. This highlights the urgent need for advanced and efficient filtration materials with low pressure drop and high-temperature resistance. Traditionally, improving filtration property has involved increasing the thickness of the filtration materials, which consequently leads to higher costs. Here, dual-scale mullite nanofiber (MNF) films containing interwoven thick nanofibers (606 nm) and thin nanofibers (186 nm) are prepared using solution blow spinning. The dual-scale structure design enables the films to maintain a low pressure drop while achieving high filtration efficiency. At an airflow velocity of 5.3 cm s^-1, the films with an areal density of 3.8 mg cm^-2, achieve a filtration efficiency of 98.23% and a pressure drop of 141 Pa for PM_0.3. In addition, the MNF films exhibit excellent flexibility and high-temperature resistance, making them have great potential for use in high-temperature flue gas filtration.