Hydrophobic Polyacrylonitrile Nanofibers for Particulate Matter Filtration

Polyacrylonitrile (PAN) polymer nanofiber membranes are recognized as one of the highly effective air filters with more than ~90% reported filtration efficiency for particulate matter (PM) pollution. Converting the PAN nanofiber membrane into a hydrophobic one is highly desirable, making it suitable for wet environmental conditions. In this work, we fabricate a PAN nanofiber filter with hydrophobic quality by infusing eggshell powder into the polymer solution and electrospinning it. Nanofibers with various possible combinations of eggshell powder infusion percentage and PAN precursor solution concentration are fabricated and evaluated for the filtration efficiency and hydrophobicity. SEM images of the membranes show the formation of beads and blends on the surface of the PAN nanofibers. Excellent hydrophobicity is observed in these composite polymers with a contact angle of ~132 ° . The filtration performance of the eggshell‐polyacrylonitrile (EGP) nanofiber filter is also evaluated by the filter quality measurement system, and filtration efficiency of ~93% is observed for a ~4‐ μ m thick membrane. We also fabricated composite PAN nanofibers embedded with fine calcium carbonate powder, which were found highly hydrophilic, confirming the protein content of eggshell responsible for hydrophobicity.