Biodegradable Poly (L‐Lactic acid) Fibrous Membrane with Ribbon‐Structured Fibers and Ultrafine Nanofibers Enhances Air Filtration Performance

Abstract Here, the poly (l‐lactic acid) (PLLA) membrane with multi‐structured networks (MSN) is successfully prepared by electrospinning technology for the first time. It is composed of micron‐sized ribbon‐structured fibers and ultrafine nanofibers with a diameter of tens of nanometers, and they are connected to form the new network structure. Thanks to the special fiber morphology and structure, the interception and electrostatic adsorption ability for against atmospheric particulate matter (PM) are significantly enhanced, and the resistance to airflow is reduced due to the “slip effect” caused by ultrafine nanofibers. The PLLA MSN membrane shows excellent filtration performance with ultra‐high filtration efficiency (>99.9% for PM 2.5 and >99.5% for PM 0.3 ) and ultra‐low pressure drop (≈20 Pa). It has demonstrated filtration performance that even exceeds current non‐biodegradable polymer materials, laying the foundation for future applications of biodegradable PLLA in the field of air filtration. In addition, this new structure also provides a new idea for optimizing the performance of other polymer materials.