Rational Process Design for Facile Fabrication of Dual Functional Hybrid Membrane of MOF and Electrospun Nanofiber towards High Removal Efficiency of PM2.5 and Toxic Gases

The application of nanofiber (NF) and porous metal-organic framework (MOF) has increasingly attracted attention for the protection of public health. This composite platform provides the physical sieving of particulate matters (PMs) and capturing gases, serving as an outstanding filtering medium with lightweight and multifunctionality. Herein, process design and optimization are performed to produce a multifunctional membrane comprised NFs and MOF particles. Electrospinning/electrospray techniques are used to fabricate a hybrid membrane of poly(vinyl alcohol) NF and Fe-BTC as an adsorptive MOF on a macroporous nonwoven (NW). Three types of filters are prepared by varying the order of processing steps, that is, MOF/NF/NW, MOF+NF/NW, and NF/MOF/NW, to elucidate the effect of the fabrication process in the filtration of air pollutant. The optimal filtration performance is achieved in MOF+NF/NW system: the highest filtration efficiency (97%) and outstanding gas capturing efficiencies (≈60% and ≈35% decreases from initial NH3 and H2 S concentrations, respectively). However, when air permeability and filtration efficiency are considered, the most desirable configuration for personal protection equipment (PPE) is NF/MOF/NW system, which effectively enabled comfortable breathing without compromising the lightweight and multifunctional performance.