Progress and perspective of polymer electret-based PM2.5 filtration: Efficiencies, regeneration, and energy implications

Abstract

High-performance PM2.5 filtration technologies are urgently needed for both air purification and energy conservation. As a superior filtration media, the polymer electret filters have attracted wide attention. Herein, the current research status of electret PM2.5 filter media are firstly analyzed from three aspects: (i) the electret properties of various electret filters, (ii) the dynamic filtration performance of typical electret filters, and (iii) the novel reusable electret filters and their regeneration technologies. Then the initial air resistance and lifespan energy consumption of a variety of mechanical and electret filter media are analyzed and compared, disclosing the advantages of charging and material compositing. Based on the analysis, perspectives on electret filter are provided from interdisciplinary views of energy, environmental and material engineering. An in-depth understanding of the charge storage characteristics of electret media at the nm and μm scales is necessary for elucidating the impact of material properties on dynamic efficiency. Meanwhile, the next generation of electret PM2.5 filters should have better dust holding capacity and regeneration performance for energy saving, but also be more versatile and intelligent to meet ever-evolving demands.