Preparation of transparent, amphiphobic and recyclable electrospun window screen air filter for high-efficiency particulate matters capture

Particulate matter (PM) pollution causes serious health risks to individuals. Using air filters to remove PMs is effective but energy intensive. An alternative to conventional air filter is to use window screen air filter to effectively block PMs from outside via natural ventilation. However, most the present window screen air filters still suffer from trade-offs among filtration efficiency, transparency and air permeability, and the filters are not reusable due to the difficulty of regeneration. In this study, an hierarchical electrospun fluorinated poly(vinylidene fluoride-co-hexafluoropropylene) (F-PVDF-HFP)/SiO2 nanofibrous filter with an average fiber diameter of about 70 nm was fabricated, which demonstrated large porosity (∼90%), good transparency (∼80%), high filtration efficiency (99.59%) and relatively low pressure drop (<0.13% of atmospheric pressure). Due to the hierarchical roughness and fluorinated surface, the filter exhibited superior amphiphobicity, and can be regenerated easily for at least 10 cycles via spray cleaning. The number of PMs re-entrained after high concentration PM loading tests was slight. The results indicated the F-PVDF-HFP)/SiO2 nanofibrous filter could be used as a high-efficiency and transparent window screen air filter. This study outlines a facile method for fabricating reusable and reliable window screen air filters that are expected to be used in practice.