Scalable antimicrobial air filters: polypropylene/rose bengal melt-blown nonwoven filters

The COVID-19 pandemic has highlighted the limitations of conventional face masks, which primarily function as aerosol physical filters without inherent antibacterial or antiviral properties. Surgical masks, which depend on electrostatic filtration, lose their efficacy as these charges dissipate within a few hours of use. This study aims to address these shortcomings by developing advanced melt-blown nonwoven filters using polypropylene (PP) and Rose bengal (RB) as a photosensitizer. The impact of varying processing temperatures during the fabrication of melt-blown nonwoven's fiber morphology, filtration efficiency, and antibacterial properties was systematically investigated. The incorporation of RB is intended to enhance antibacterial activity. Results show that processing temperature significantly influences fiber diameter, with optimized filters demonstrating superior antibacterial performance (>99 %), particulate filtration efficiency (PFE) of 63 % compared to conventional masks. These filters with advanced functionality present promising improvements in antimicrobial protection from the ambient environment and durability, contributing to the development of more effective and long-lasting personal protective equipment (PPE).