Organic Semiconductor‐Mediated Electrospinning: Bimodal Micro‐Nano Fiber Membranes with Precise Diameter Control for Multifunctional Air Purification

Electrospinning is a promising technique for fabricating air filtration materials. Nevertheless, significant challenges remain in precise fiber diameter control, efficiency-pressure drop balance, and achieving multifunctional air purification. In this study, an organic semiconductor material (PDINN) is first utilized to modulate the fiber diameters of PLA nanofiber membranes (PDINN@PLA) by electrospinning. Due to the relatively high conductivity of PDINN, the fiber diameters were reduced from 2 µm to 500 nm. Subsequently, PDINN@PLA was employed in combination with PLA to fabricate the bimodal micro-nanofiber membrane, named PLA-PDINN@PLA. Benefiting from the gradient distribution of fiber diameters, PLA-PDINN@PLA has filtration efficiency of more than 99.5% for PM_0.3, maintained low pressure drop at air flow rates of both 32 and 85 L/min. In addition to remarkable filtration performance, this membrane also demonstrates excellent antibacterial properties, achieving inhibition rates of 99.99% against both S. aureus and E. coli. Meanwhile, the membrane exhibits deodorization efficiencies of 99.99% and 82% for ammonia and acetic acid, respectively, which can be attributed to the amino groups in PDINN. Therefore, this work presents an innovative strategy that enables simultaneous control over fiber diameters and functionalization of fibrous membranes, offering a promising approach toward highly efficient multifunctional nanofiber-based air filters.