Particulate matter (PM) is a major air pollutant, which has a significant impact on public health. Filtration of PM through filters is a common method to protect the environment. However, the effective removal of PM with conventional filters still remains a challenge because of its small sizes. Here, we reported the formation of ultrafine polyamide 6 (PA‐6) nanofiber membranes formed with needleless electrospinning, in which both relative humidity condition and electrode type were included in the discussion. The PA‐6S nanofibers formed by using spiral electrode as a spinneret at 60% RH had the diameter of 33 nm, while the PA‐6C nanofibers formed by using cylindrical electrode had the diameter of 120 nm. With the integration of fine diameter, small pore size, and high porosity, the resultant PA‐6S nanofiber membrane exhibits high filtration efficiency of 99.42% and low pressure drop of 85.5 Pa under a face velocity of 85 L/min. Besides, it took only 10 minutes to reduce the concentration of PM2.5 from 999 to 34.1 μg/m3 when used to filter real PM particles.

The formation of multi-layer nylon-6 (PA-6) nanofibrous membranes by electrostatic spinning coupled with a hot pressing process, and they can be used for efficient and continuous indigo dye filtration.

We report a facile route to synthesize novel microstructured SiCNO films via a block copolymer micellar-templating approach, in which polyvinylsilazane (PVSZ)-swelled F127 micelles are used as a precursor and the crystallization of the PEO shell of PVSZ-swelled F127 micelles is used to control the microstructure of SiCNO films. By changing the evaporation temperature of multistep thermal treatments, SiCNO films containing nanospheres, rods, crosses, cuboids, and microspheres can be formed. We find that these microstructures have a significant effect on the dielectric loss of SiCNO films, which can be explained by the Maxwell-Wagner effects and impurities at interfaces.