High-efficiency and super-breathable air filters based on biomimetic ultrathin nanofiber networks

Air pollution resulted from particulate matter (PM) has rendered great risks to the global safety concerns. However, most existing filters used for air filtration are usually thick, bulky, and suffer from the trade-off between filtration capability and air permeability. Here, for the first time, an innovative electronetting technique is reported to create continuous and totally integrated 2D ultrathin polyacrylonitrile nanonets with true nanoscale fiber diameters (~30 nm) and 2D spider-web-like network structures. Such ultrafine diameters combined with their small pore sizes (~0.26 μm) endowed the 2D nanonet filters with greatly enhanced PM capture capacity (PM0.3 removal efficiency of 99.996%). Meanwhile, the features of thin thickness (~0.4 μm), high porosity (92.1%), and ultra-light base weight (0.68 g m−2) allowed the filters to exhibit low air resistance of 73.5 Pa. This work may shed light on developing new type of high-performance air filters for environmental and public protection.