In this work, the interfacial effect on the air resistance of the expanded polytetrafluoroethylene/polyphenylene sulfide (ePTFE/PPS) composite membrane was investigated experimentally and by numerical simulation. PPS fiber melting-caused diffusion, porosity reduction in laminating process, and turbulence effect of sudden changed airflow direction are confirmed to be the primary causes of the additional resistance, which occupy more than 40% of the total resistance. To eliminate the influence of PPS fiber melting-induced pore blocking in laminating process, the model modification parameter c and air permeability effective coefficient (σ) were introduced based on a digital image processing technology. A mathematical model was then established to predict and optimize the composite membrane. The predictions from the theoretical calculation were quantitatively in good agreement with the experimental measurements. It was found that profiled fiber with smaller intersection angle and diameter ratio can effectively decrease ~86% of IIR.

The strategy of constructing catalytic membrane has a significant influence on its structure and performance. In this work, Co3O4-Cx@SiO2 nanofiber membranes (NFMs) were fabricated by an in-situ growth–pyrolysis–oxidation strategy. The Co3O4-Cx catalyst derived from ZIF-67 was wrapped around nanofibers, which helps to maintain a stable membrane structure, then suppressing the reduction of gas permeability. Among the Co3O4-Cx catalyst, the carbon skeleton can prevent the agglomeration of Co3O4 nanoparticles, obtaining an ultra-fine Co3O4 nanoparticles with high dispersibility, redox property and surface area. The obtained Co3O4-C300@SiO2 NFM exhibits excellent filtration efficiency and low pressure drop for PM2.5 (99.99% and 55 Pa) and outstanding catalytic performance with T90 of 245 °C for NH3-SCR, which is 40.3% higher than that of Co3O4@SiO2 NFM. This work might provide a universal strategy for the preparation of catalytic membrane with high-performance.