Electrospun Polymethylhydrosiloxane/Poly(lactic acid) Multiscale Nanofiber Membrane with Highly Hydrophobic Interface as Material for Protective Mask Filters

The development of high-performance, fully biodegradable air filtration materials has become a current research hotspot owing to their significant applications in environmental and personal protection; however, an inherent contradiction exists between the pressure drop and filtration efficiency of existing filter materials. To introduce the slippage effect into nanofiber membranes, a multiscale-structured air filtration material comprising scaffold fibers (200 nm) and functional fibers (32 nm) with superior slippage effect properties is designed using the COMSOL software to increase interfiber spacing. Ultrafine polylactic acid nanofibers (32 ± 5 nm) doped with polymethylhydrosiloxane are designed and fabricated by electrospinning. A multiscale nanofiber structure is engineered by adjusting the diameters of various spinning units to effectively reconcile the trade-off between filtration efficiency and resistance. The membrane exhibits a small pore size (0.62 μm), high porosity (93.21%), highly hydrophobicity (water contact angle 144.8°), high PM 0.3 removal efficiency (99.99%), low air resistance (68.23 Pa), and a PM 0.3 filtration efficiency for PM 0.3 of 95.62% after static charge decay treatment. This membrane material also exhibits complete biodegradability and filtration stability for 12 h after PM interception (>99.0%). This work provides insights into the application of polylactic acid nanofibers in fields requiring high-precision protection and filtration materials.