Flexible Multifunctional Porous Nanofibrous Membranes for High-Efficiency Air Filtration.

Particulate matters (PMs) discharged along with the rapid industrialization and urbanization hazardously threaten ecosystems and human health. Membrane-based filtration technology has been proved to be an effective approach to capture PMs from the polluted air. However, the fabrication of filtration membranes with excellent reusability and antibacterial activity has rarely been reported. Herein, the flexible multifunctional porous nanofibrous membranes were fabricated by embedding Ag nanoparticles into the electrospun porous SiO2-TiO2 nanofibers via an impregnation method, which integrated the abilities of PM filtration and antibacterial performance. Compared with the reported air filters, the resultant membrane (Ag@STPNM) with high surface polarity and the porous structure possessed the low density, high removal efficiency, and small pressure drop. For instance, the removal efficiency and the pressure drop of Ag@STPNM with basis weight of only 3.9 g·m-2 for PM2.5 reached to 98.84% and 59 Pa, respectively. In terms of the excellent thermal stability of Ag@STPNM, the adsorbed PMs could be removed simply by a calcination process. The filtration performance of Ag@STPNM kept stable during five purification-regeneration cycles, and the long-time filtration for 12 h, exhibiting excellent recyclability and durability. Furthermore, the embedded Ag nanoparticles could achieve the effective resistance to the breeding of bacteria on Ag@STPNM, giving the bacteriostatic rate of 95.8%. Therefore, Ag@STPNM holds promising potentials as a highly efficient, reusable, and antibacterial air filter in the practical purification of indoor environment or personal air.