High-performance bag filter with a super-hydrophobic microporous polytetrafluoroethylene layer fabricated by air-assisted electrospraying

Reducing PM emissions from industrial sites has become increasingly important as the adverse health effects of particulate matter have been demonstrated by multiple epidemiological and toxicological studies. High-performance bag filters are often used for this purpose. We fabricated polytetrafluoroethylene (PTFE) nanoparticle (NP)-coated high-efficiency bag filters using air-assisted electrospraying (AAES) technology. AAES functionalized with a combination of airflow drag force and an applied electric field facilitates high-throughput without requiring additional purification or preparation process of a PTFE emulsion. PTFE NPs form a unique three-dimensional microporous structure on a foam-filter medium, enhancing mechanical filtration performance (diffusion and interception). Moreover, the surface hydrophobicity was significantly improved as the PTFE NPs covered the bag filter surface. These factors highlight the feasibility of large-scale implementation of PTFE NP-coated bag filters for reducing PM emissions from industrial sources.