“Moisture-gas dual-effect”: Three-layer leaf-vein-inspired nanofiber filter membrane based on multi-gradient structure for personal protection in high-dust environments

Designed MC-loaded leaf-vein-inspired 3-layer gradient P224 membrane with multi-functions for high-dust protection. • Combined electrospinning with pore/wettability gradient to make filter with dust removal & moisture transport. • Achieved dual mechanism of efficient dust filtration and unidirectional moisture transport. • Enabled P224 use in high-dust environments, promoting next-gen personal respiratory protective equipment. Herein, we designed a facial nanofiber filter capable of efficiently adsorbing dust and achieving unidirectional water transport for moisture wicking (named P224). Multifunctional filtering fiber membrane loaded with Cu-MOF@MXene (MC) was successfully prepared via electrospinning, based on a three-layer leaf-vein-inspired multi-gradient structure. From inner to outer layers, P224 consists of PVDF@MC, PVDF/PVA, and PVA@MC. The decreasing fiber pore size gradient and the increasing wettability gradient enable it to have both mechanical filtration and single-stream water transport functions. The P224 fiber membrane prepared under the optimal ratio and spinning conditions has a filtration performance of up to 99.2% for PM0.3 (NaCl aerosol), an increased self-cleaning ability of approximately 150%, an antibacterial rate of 90% against Staphylococcus aureus . The test results of the unidirectional water transmission experiment and the water vapor transmission meter show that the water vapor transmission rate of this fiber membrane is 1542 g/(m 2 ·24h), and it has very good unidirectional water transmission capacity. This “moisture-gas dual-effect” nanofiber protective dust-filtering membrane paved the way for the design of personal protective equipment. We designed a three-layer leaf-vein-inspired nanofiber filter membrane (P224) via electrospinning, composed of inner PVDF@MC, middle PVDF/PVA, and outer PVA@MC. It has pore size and wettability gradients, enabling “moisture-gas dual-effect”. Optimized P224 shows 99.2% PM2.5 filtration efficiency, ∼150% enhanced self-cleaning, 90% antibacterial rate against Staphylococcus aureus , 1542 g/(m 2 ·24h) water vapor transmission rate, and good unidirectional water transport, laying a foundation for personal protective equipment. Download: Download high-res image (350KB) Download: Download full-size image