In-situ grown nanofiber-decorated microfibrous nonwovens boosting air filtration and heat dissipation

Air pollution remains a pressing global challenge, necessitating the urgent development of advanced air filtration and protection technologies. Although personal protective masks have addressed the concerns to some extent, designing those that combine high filtration efficiency with low pressure drop and enhanced wearing comfort are still desirable. To remove this hurdle, we here harness a direct freeze-drying strategy to enable in-situ grown polyethylene oxide (PEO) nanofibrous structures (ranging from 10 nm to several hundred nanometers) into polypropylene (PP) melt-blown (MB) nonwovens (1–10 μm). Compared to the original PP MB nonwovens, the PEO nanofiber-decorated counterparts demonstrate a remarkable improvement in filtration efficiency, increasing from 30 % to 99.8 %, alongside an approximately two-fold enhancement in the quality factor. Furthermore, the addition of the PEO nanofibrous structure significantly enhanced the thermal conductivity of the material, enabling superior heat dissipation. Notably, the minimum air permeability of the PEO/PP-nano/microfibrious nonwovens (PEO/PP-NMNs) remained as high as 340 mm/s, even after incorporation of the nanofiber network. These findings underscore the potential of PEO/PP-NMNs as promising materials for next-generation personal protective equipment.