Conformal Build‐Up of Functionalized Air Filters with Improved Air Cleaning and Bioprotective Traps

Abstract Air filtration is vital for passive pollution control toward advanced manufacturing industries and human health protection. However, large‐scale air‐filter utilization is limited by high energy costs. Therefore, it is crucial to develop filter media that exhibit a high removal efficiency, low pressure drop, and stable biocidal effects. This study reports an efficient and scalable bottom‐up approach for fabricating shellac‐based glass fiber matrices with bioprotective traps (GFMs‐traps) with tunable conformal micro/nanostructures, superhydrophobicity, and biocidal functions. The synthesis, which involves freeze‐drying‐free ice‐shellac double‐template formation, perfluorosilane‐based grafting, and filtration, eliminates capillary‐force‐induced micro/nanofibrous cluster formation. Theoretical modeling and experimental results indicate that the air cleaning and biocidal properties of the GFMs‐traps can be attributed to their uniformly distributed micro/nanofibrous structures and stable nanoparticle (NP) coatings (AgNPs, CuNPs, and TiO₂NPs). The GFMs‐traps exhibit integrated air cleaning, with excellent filtration performance at the most penetrating particle size (99.97%, 234 Pa), superhydrophobicity (≥150°), a high virus‐filtration efficiency (99.995%), and good antibacterial and antiviral activity. Additionally, a commercial air purifier comprising a GFMs‐trap filter exhibits high potential for commercial applications. The facile strategy for fabricating high‐performance bioprotective filter media reported here may facilitate advanced large‐scale air filtration applications in the future.