Environmentally durable and washable tanghulu-like amphiphobic fluorinated PVA/SiO2 electrospun nanofibrous membrane for efficient and reusable oil aerosol filtration

The filtration of oil aerosols is crucial for safeguarding human health and protecting industrial machinery. While most research focuses on achieving high efficiency and low air resistance, limited studies have investigated filters that effectively combine these attributes with easy cleaning, primarily due to challenges associated with oil adhesion and the low mechanical strength of filter media. This study introduces a novel nanofibrous membrane (NFM) composed of fluorinated PVA/SiO 2 fibers, which exhibits cleanability alongside with high filtration efficiency. The F-PVA/SiO 2 NFM features a fibrous structure with periodic SiO 2 nano-protrusions on the PVA nanofibers, resembling the Chinese sweet Tanghulu . This design significantly enhances the surface roughness of the fibers. Moreover, the hydroxyl-rich PVA/SiO 2 matrix, in conjunction with the rough fiber surface, forms a durable amphiphobic coating after fluorination treatment. This coating retains its amphiphobic properties for over a year under ambient conditions while resisting swelling caused by organic solvents. Consequently, this design achieves an impressive filtration quality factor of 0.0190 Pa −1 , surpasses 95.58 % removal efficiency, and possessed an oil load capacity of 12.8 g m −2 . Furthermore, the filter can be easily regenerated through simple spray cleaning procedures without compromising its original filtration efficiency or experiencing significant pressure drop changes. Throughout ten consecutive filtration and cleaning cycles, the NFM consistently maintained its original filtration efficiency, with a 99 % restoration of pressure drop after each cycle. This F-PVA/SiO 2 NFM presents a practical solution for efficient oil aerosol filtration while offering excellent reusability and durability.