High Efficiency Antibacterial, Moisture Permeable, and Low Temperature Comfortable Janus Nanofiber Membranes for High Performance Air Filters and Respiration Monitoring Sensors

In this work, high efficiency and multifunctional poly(vinyl alcohol-co-ethylene) nanofiber, Ag particle, and polypropylene (PP) meltblown nonwoven substrate composite (NF@Ag) air filters by a simple spray coating method and subsequent UV irradiation treatment are demonstrated. The water vapor transmission rate of the NF@Ag-4 air filter is 4753.36 ± 316.75 g/(m² d), which is higher than that of commercial PP nonwoven (4240.71 ± 354.36 g/(m² d)). It is can be explained that the NF@Ag-4 air filter is a Janus structure with asymmetric wettability, which enhances moisture permeability, thereby improving comfort while wearing. The NF@Ag-2 air filter exhibits high filtration efficiency (95.80 ± 0.89%) and relatively low pressure drop (122.00 ± 1.73 Pa) without relying on the electrostatic adsorption effect. The resulting NF@Ag air filters display excellent antibacterial properties against Escherichia coli and Staphylococcus aureus, photothermal disinfection, and thermal insulation performance. Furthermore, the as-prepared NF@Ag air filters can be simply patterned and designed as respiration monitoring sensors to precisely detect the respiratory activity and health of the human being. Therefore, it is believed that these multifunctional air filters will have good potential for applications in the removal of particular matters and breathable wearable electronic devices.