Engineering electrospun PAN/PCL blend for high-performance and eco-friendly particulate matter filtration

Abstract

Particulate matter (PM) is an air pollutant that poses a significant threat to human health. Efficient air filters are crucial for reducing PM pollution. However, several existing filtration materials fail under vigorous motion, such as twisting or stretching by high-velocity airflows, owing to their poor mechanical properties. In this study, we designed and fabricated a highly stretchable and biodegradable PM filtration membrane using electrospun polyacrylonitrile (PAN)/polycaprolactone (PCL) blended nanofibers. Our study incorporated polymer blend theory, particularly Hansen's solubility theory, to determine an optimal composition that not only provides particle absorption properties (minimizing PAN content without compromising absorption performance), but also significantly improves stretchability and biodegradability (maximizing PCL content). The resulting PAN/PCL air filters exhibited 100-times-enhanced stretchability and high filtration efficiency for PM2.5 (99.95%) and PM10 (99.89%), with a simultaneous low-pressure drop (121 Pa, only <1% of atmospheric pressure) under a high gas flow velocity (5 L/min ≈ face velocity of 0.3 m/s). Moreover, the 50/50 wt% PAN/PCL air filter demonstrated biodegradability, showing weight loss of up to 40% after 72 h of enzymatic degradation. Our highly efficient and biodegradable air filter, fabricated using PAN/PCL-blended nanofibers, offers new perspectives for the design and preparation of high-performance filtration materials. Moreover, it has potential applications in air pollution control and environmental protection.