Utilizing electrostatic effect in fibrous filters for efficient airborne particles removal: Principles, fabrication, and material properties

Particulate matter (PM) poses a severe health threat to the public, and fibrous filtration is a powerful method for efficient PM removal. Arming the fibers with electrostatic effect is a gold rush to promote PM-fiber interaction, thus reaching high PM removal efficiency, decreasing airflow resistance, and achieving multifunctional applications simultaneously. In this study, we are to provide a comprehensive overview of electrostatic fibrous filters, including the principles, fabrication process, electrical properties, and applications. Firstly, PM-fiber adhesion forces during the filtration were analyzed according to the electrified principle for the filters. Furthermore, electrostatic filters were classified into monopolar-charged and dipolar-induced filters in the dimension of charging characteristics. Compared with other PM removal techniques, the electrical properties, comprehensive performance, and applications for various electrostatic filters are systematically stated and discussed. In the end, we highlighted that the electrostatic fibrous filters would be a competitive candidate for PM removal owing to their durability, versatility, and plasticity. We also discussed the importance of conducting rigorous filtration tests to report accurate performance for electrostatic filters. In an interdisciplinary view between environmental engineering and material engineering, we hope this work could provide a better understanding of the PM-fiber electrostatic interactions and practical insights for designing next-generation air filters.