In situ one-step production of hierarchical silicon nanofilaments/polyimide nonwovens for environmentally sustainable applications

Highly architectures with roughness and low surface energy reagent are the key toward developing superwetting materials. Silicon nanofilaments (SiNFs) had been grown on polyimide (PI) nonwovens by liquid deposition, which could enhance the hydrophobicity of the nonwovens without additives. These newly prepared nonwovens with micro/nano-scale secondary rough structures demonstrate outstanding air filtration and oil/water separation abilities. The in situ hybrid nonwoven shows extremely high efficiency air filtration function (the increase in filtration efficiency for PM1.0 by 63 % with stable pressure drop), stable particulate filtering effect after storage 15 months at ambient temperature, and good thermal stability at 350 °C. The oil/water separation test showed a separation efficiency of over 98 % and a high flux (above 40,000 Lm-2h−1) for different oil/water mixtures. Additionally, nonwovens prepared in this study demonstrated exceptional durability and stability when subjected to corrosive conditions, as evidenced by the results of realistic industrial simulations. The introduction of SiNFs on nonwoven, which combines the multiple capture and wettability properties, shows promise as a potential solution for large-scale air filtration and oil/water separation.