Gelatin/β–Cyclodextrin Bio–Nanofibers as respiratory filter media for filtration of aerosols and volatile organic compounds at low air resistance

Air pollution is a universal concern. The suspended solid/liquid particles in the air and volatile organic compounds (VOCs) are ubiquitous. Synthetic polymer-based air filter media not only has disposal issues but also is a source of air and water pollution at the end of their life cycle. It has been a challenge to filter both particulate matter and VOC pollutants by a common biodegradable filter media having low air resistance. This study reports gelatin/β–cyclodextrin composite nanofiber mats with dual function air filtration ability at reduced air resistance (148 Pa) and low basis weight (1 g/m²). Gelatin/β–cyclodextrin nanofibers captured aerosols (0.3–5 μm) with < 95% filtration efficiency at 0.029/Pa quality factor. They adsorbed great amount of xylene (287 mg/g), benzene (242 mg/g), and formaldehyde (0.75 mg/g) VOCs. VOC adsorption of gelatin/β–cyclodextrin nanofibers is found several times higher than a commercial face mask and pristine powder samples. This study provides a solution for a ‘green’ dual function respiratory air filtration at low resistance. Gelatin/β–cyclodextrin nanofibers also have the potential to filter nano-sized viruses.